Transmembrane protease, serine 6 (TMPRSS6) iRNA compositions and methods of use thereof

SEQUENCE LISTING

The instant application contains a Sequence Listing which has been filed electronically in XML file format and is hereby incorporated by reference in its entirety. Said XML copy, created on Dec. 21, 2022, is named 121301-015403_SL.xml and is 18,616,211 bytes in size.

BACKGROUND OF THE INVENTION

TMPRSS6 (Transmembrane Protease, Serine 6), also known as matriptase-2, is a type II serine protease. It is primarily expressed in the liver, although high levels of TMPRSS6 mRNA are also found in the kidney, with lower levels in the uterus and much smaller amounts detected in many other tissues (Beliveau et al., 2019, Cell Chemical Biology 26, 1559-1572). TMPRSS6 plays a key role in iron homeostatis via modulation of hepcidin expression. Hepcidin, a liver-derived peptide hormone, is known as a central regulator of systemic iron homeostasis, and its unbalanced production contributes to the pathogeesis of a spectrum of iron disorders. Hepcidin functions by blocking the absorption of dietary iron from the intestine, and the release of iron from macrophages and hepatocytes (Ganz T. 2011, Blood, vol. 117, 17, 4425-4433). Hepcidin gene expression can be stimulated in response to iron through BMP/SMAD-dependent signal transduction cascade mediated by the BMP-co-receptor hemojuvelin (HJV). TMPRSS6 inhibits BMP-mediated upregulation of hepcidin by cleaving the BMP co-receptor HJV, thus preventing BMP signaling, SMAD translocation to the nucleus, and hepcidin transcriptional activation, which causes downregulation of hepcidin levels (Finberg, K. E., et al., 2010, Blood 115, 3817-3826; Wang, C. Y., et al., 2014 Front. Pharmacol. 5, 114).

Therefore, inhibition of TMPRSS6 results in increased hepcidin levels, making it an attractive pharmacological target for disorders associated with iron overload and inappropriately low hepcidin or for disorders where iron restriction is desirable. Numerous disorders, such as thalassemias, hemochromatosis, and certain types of myelodysplastic syndromes (MDS), are associated with iron overload, a condition characterized by increased levels of iron. Iron overload can result in excess iron deposition in various tissues and can eventually lead to tissue and organ damage. In addition, iron restriction is desirable in certain disorders such as polycythemia vera.

Current treatments for disorders associated with iron overload and disorders where iron restriction is desirable (e.g. polycythemia vera) include phlebotomy or venesection, a treatment to remove iron-rich blood from the body; splenectomy; iron chelation therapy; and dieting. However, these treatments are not always effective. Accordingly, there is a need in the art for alternative treatments for subjects having disorders associated with iron overload.

SUMMARY OF THE INVENTION

The present invention provides iRNA compositions which affect the RNA-induced silencing complex (RISC)-mediated cleavage of RNA transcripts of a gene encoding Transmembrane protease, serine 6 (TMPRSS6). The TMPRSS6 gene may be within a cell, e.g., a cell within a subject, such as a human subject. The present invention also provides methods of using the iRNA compositions of the invention for inhibiting the expression of a TMPRSS6 gene and/or for treating a subject who would benefit from inhibiting or reducing the expression of a TMPRSS6 gene, e.g., a subject suffering or prone to suffering from a TMPRSS6-associated disorder, e.g., an iron overload associated disorder and/or a disorder of ineffective erythopoiesis, such as thalassemia, e.g., β-thalassemia, hemochromatosis, myelodysplastic syndromes (MDS), or polycythemia vera.

Accordingly, in an aspect, the present invention provides a double stranded ribonucleic acid (dsRNA) for inhibiting expression of Transmembrane protease, serine 6 (TMPRSS6) in a cell, wherein said dsRNA comprises a sense strand and an antisense strand forming a double stranded region, wherein the antisense strand comprises a region of complementarity to an mRNA encoding TMPRSS6, and wherein the region of complementarity comprises at least 15, e.g., 15, 16, 17, 18, 19, or 20, contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from any one of the antisense nucleotide sequences in any one of Tables 2-7.

In one embodiment, the dsRNA agent comprises a sense strand comprising a contiguous nucleotide sequence which has at least 85%, e.g., 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%, nucleotide sequence identity over its entire length to any one of the nucleotide sequences of the sense strands in any one of Tables 2-7 and an antisense strand comprising a contiguous nucleotide sequence which has at least 85%, e.g., 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%, nucleotide sequence identity over its entire length to any one of the nucleotide sequences of the antisense strands in any one of Tables 2-7.

In one embodiment, the dsRNA agent comprises a sense strand comprising at least 15, e.g., 15, 16, 17, 18, 19, 20, or 21, contiguous nucleotides differing by no more than three nucleotides from any one of the nucleotide sequences of the sense strands in any one of Tables 2-7 and an antisense strand comprising at least 15, e.g., 15, 16, 17, 18, 19, 20, or 21, contiguous nucleotides differing by no more than three nucleotides from any one of the nucleotide sequences of the antisense strands in any one of Tables 2-7.

In one embodiment, the dsRNA agent comprises a sense strand comprising at least 15, e.g., 15, 16, 17, 18, 19, 20, or 21, contiguous nucleotides differing by no more than two nucleotides from any one of the nucleotide sequences of the sense strands in any one of Tables 2-7 and an antisense strand comprising at least 15, e.g., 15, 16, 17, 18, 19, 20, or 21, contiguous nucleotides differing by no more than two nucleotides from any one of the nucleotide sequences of the antisense strands in any one of Tables 2-7.

In one embodiment, the dsRNA agent comprises a sense strand comprising at least 15, e.g., 15, 16, 17, 18, 19, 20, or 21, contiguous nucleotides differing by no more than one nucleotide from any one of the nucleotide sequences of the sense strands in any one of Tables 2-7 and an antisense strand comprising at least 15, e.g., 15, 16, 17, 18, 19, 20, or 21, contiguous nucleotides differing by no more than one nucleotide from any one of the nucleotide sequences of the antisense strands in any one of Tables 2-7.

In one embodiment, the dsRNA agent comprises a sense strand comprising or consisting of a nucleotide sequence selected from the group consisting of any one of the nucleotide sequences of the sense strands in any one of Tables 2-7 and an antisense strand comprising or consisting of a nucleotide sequence selected from the group consisting of any one of the nucleotide sequences of the antisense strands in any one of Tables 2-7.

In one aspect, the present invention provides a double stranded ribonucleic acid (dsRNA) for inhibiting expression of Transmembrane protease, serine 6 (TMPRSS6) in a cell, wherein said dsRNA comprises a sense strand and an antisense strand forming a double stranded region, wherein the sense strand comprises at least 15, e.g., 15, 16, 17, 18, 19, 20, or 21, contiguous nucleotides differing by no more than three, e.g., 3, 2, 1, or 0, nucleotides from any one of the nucleotide sequence of nucleotides 187-210; 227-254; 322-363; 362-390; 398-420; 404-429; 410-435; 439-461; 443-467; 448-474; 460-483; 466-488; 496-519; 519-542; 526-548; 557-593; 641-671; 652-676; 687-713; 725-762; 757-794; 886-908; 921-951; 956-987; 1051-1082; 1233-1269; 1279-1313; 1313-1341; 1327-1351; 1415-1439; 1447-1480; 1464-1486; 1486-1509; 1559-1589; 1571-1595; 1579-1609; 1707-1735; 1738-1764; 1806-1828; 1864-1886; 1934-1966; 1967-1991; 2008-2031; 2015-2043; 2042-2072; 2287-2311; 2297-2354; 2336-2361; 2360-2384; 2416-2438; 2481-2510; 2496-2527; 2526-2558; 2665-2693; 2693-2719; 2707-2729; 2799-2821; 2851-2874; 2971-2999; 2981-3006 and 3155-3195 of SEQ ID NO: 1, and the antisense strand comprises at least 15 contiguous nucleotides differing by no more than 3, e.g., 3, 2, 1, or 0, nucleotides from the corresponding nucleotide sequence of SEQ ID NO:2.

In one aspect, the present invention provides a double stranded ribonucleic acid (dsRNA) agent for inhibiting expression of Transmembrane protease, serine 6 (TMPRSS6) in a cell, wherein the dsRNA agent comprises a sense strand and an antisense strand forming a double stranded region, wherein the sense strand comprises at least 15, e.g., 15, 16, 17, 18, 19, 20, or 21, contiguous nucleotides differing by no more than three, e.g., 3, 2, 1, or 0, nucleotides from any one of the nucleotide sequence of nucleotides 230-252, 324-346, 560-578, 560-582, 2338-2360, 3163-3185, 3169-3191, and 3172-3194 of SEQ ID NO: 1, and the antisense strand comprises at least 15, e.g., 15, 16, 17, 18, 19, 20, or 21, contiguous nucleotides differing by no more than three, e.g., 3, 2, 1, or 0, nucleotides from the corresponding nucleotide sequence of SEQ ID NO:2.

In one aspect, the present invention provides a double stranded ribonucleic acid (dsRNA) agent for inhibiting expression of Transmembrane protease, serine 6 (TMPRSS6) in a cell, wherein the dsRNA agent comprises a sense strand and an antisense strand forming a double stranded region, wherein the sense strand comprises at least 15, e.g., 15, 16, 17, 18, 19, 20, or 21, contiguous nucleotides differing by no more than three, e.g., 3, 2, 1, or 0, nucleotides from any one of the nucleotide sequence of nucleotides 560-578, 2338-2360, and 3169-3191 of SEQ ID NO: 1, and the antisense strand comprises at least 15, e.g., 15, 16, 17, 18, 19, 20, or 21, contiguous nucleotides differing by no more than 3, e.g., 3, 2, 1, or 0, nucleotides from the corresponding nucleotide sequence of SEQ ID NO:2.

In some embodiments, the antisense strand comprises at least 15, e.g., 15, 16, 17, 18, 19, 20, or 21, contiguous nucleotides differing by no more than three, e.g., 3, 2, 1, or 0, nucleotides from any one of the antisense strand nucleotide sequences of a duplex selected from the group consisting of AD-1556360, AD-1571158, AD-1571033, AD-1554875, AD-1571160, AD-1555117, AD-1554911, and AD-1556915.

In one embodiment, the dsRNA agent comprises at least one modified nucleotide.

In one embodiment, substantially all of the nucleotides of the sense strand; substantially all of the nucleotides of the antisense strand comprise a modification; or substantially all of the nucleotides of the sense strand and substantially all of the nucleotides of the antisense strand comprise a modification.

In one embodiment, all of the nucleotides of the sense strand comprise a modification; all of the nucleotides of the antisense strand comprise a modification; or all of the nucleotides of the sense strand and all of the nucleotides of the antisense strand comprise a modification.

In one embodiment, at least one of the modified nucleotides is selected from the group consisting of a deoxy-nucleotide, a 3′-terminal deoxythimidine (dT) nucleotide, a 2′-O-methyl modified nucleotide, a 2′-fluoro modified nucleotide, a 2′-deoxy-modified nucleotide, a locked nucleotide, an unlocked nucleotide, a conformationally restricted nucleotide, a constrained ethyl nucleotide, an abasic nucleotide, a 2′-amino-modified nucleotide, a 2′-O-allyl-modified nucleotide, 2′-C-alkyl-modified nucleotide, 2′-hydroxly-modified nucleotide, a 2′-methoxyethyl modified nucleotide, a 2′-O-alkyl-modified nucleotide, a morpholino nucleotide, a phosphoramidate, a non-natural base comprising nucleotide, a tetrahydropyran modified nucleotide, a 1,5-anhydrohexitol modified nucleotide, a cyclohexenyl modified nucleotide, a nucleotide comprising a phosphorothioate group, a nucleotide comprising a methylphosphonate group, a nucleotide comprising a 5′-phosphate, a nucleotide comprising a 5′-phosphate mimic, a thermally destabilizing nucleotide, a glycol modified nucleotide (GNA), a nucleotide comprising a 2′ phosphate, and a 2-O—(N-methylacetamide) modified nucleotide; and combinations thereof.

In one embodiment, the modifications on the nucleotides are selected from the group consisting of LNA, HNA, CeNA, 2′-methoxyethyl, 2′-O-alkyl, 2′-O-allyl, 2′-C-allyl, 2′-fluoro, 2′-deoxy, 2′-hydroxyl, and glycol; and combinations thereof.

In one embodiment, at least one of the modified nucleotides is selected from the group consisting of a deoxy-nucleotide, a 2′-O-methyl modified nucleotide, a 2′-fluoro modified nucleotide, a 2′-deoxy-modified nucleotide, a glycol modified nucleotide (GNA), e.g., Ggn, Cgn, Tgn, or Agn, a nucleotide with a 2′ phosphate, e.g., G2p, C2p, A2p or U2p, and, a vinyl-phosphonate nucleotide; and combinations thereof.

In some embodiments, the modified nucleotide comprises a short sequence of 3′-terminal deoxythimidine nucleotides (dT).

In some embodiments, the dsRNA agent further comprises at least one phosphorothioate internucleotide linkage. In some embodiments, the dsRNA agent comprises 6-8 phosphorothioate internucleotide linkages. In one embodiment, the phosphorothioate or methylphosphonate internucleotide linkage is at the 3′-terminus of one strand. Optionally, the strand is the antisense strand. In another embodiment, the strand is the sense strand. In a related embodiment, the phosphorothioate or methylphosphonate internucleotide linkage is at the 5′-terminus of one strand. Optionally, the strand is the antisense strand. In another embodiment, the strand is the sense strand. In another embodiment, the phosphorothioate or methylphosphonate internucleotide linkage is at the both the 5′- and 3′-terminus of one strand. Optionally, the strand is the antisense strand. In another embodiment, the strand is the sense strand.

The double stranded region may be 19-30 nucleotide pairs in length; 19-25 nucleotide pairs in length; 19-23 nucleotide pairs in length; 23-27 nucleotide pairs in length; or 21-23 nucleotide pairs in length.

In one embodiment, each strand is independently no more than 30 nucleotides in length.

In one embodiment, the sense strand is 21 nucleotides in length and the antisense strand is 23 nucleotides in length.

The region of complementarity may be at least 17 nucleotides in length; between 19 and 23 nucleotides in length; or 19 nucleotides in length.

In one embodiment, at least one strand comprises a 3′ overhang of at least 1 nucleotide. In another embodiment, at least one strand comprises a 3′ overhang of at least 2 nucleotides.

In one embodiment, the dsRNA agent further comprises a ligand.

In one embodiment, the ligand is conjugated to the 3′ end of the sense strand of the dsRNA agent.

In one embodiment, the ligand is conjugated to the 5′ end of the sense strand of the dsRNA agent.

In one embodiment, the ligand is an N-acetylgalactosamine (GalNAc) derivative.

In one embodiment, the ligand is one or more GalNAc derivatives attached through a monovalent, bivalent, or trivalent branched linker.

In one embodiment, the ligand is

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In one embodiment, the dsRNA agent is conjugated to the ligand as shown in the following schematic

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and, wherein X is O or S.

In one embodiment, the X is O.

In one embodiment, the dsRNA agent is conjugated to the ligand as shown in the following schematic

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In one embodiment, the dsRNA agent further comprises at least one phosphorothioate or methylphosphonate internucleotide linkage.

In one embodiment, the phosphorothioate or methylphosphonate internucleotide linkage is at the 3′-terminus of one strand, e.g., the antisense strand or the sense strand.

In another embodiment, the phosphorothioate or methylphosphonate internucleotide linkage is at the 5′-terminus of one strand, e.g., the antisense strand or the sense strand.

In one embodiment, the phosphorothioate or methylphosphonate internucleotide linkage is at the both the 5′- and 3′-terminus of one strand. In one embodiment, the strand is the antisense strand.

In one embodiment, the base pair at the 1 position of the 5′-end of the antisense strand of the duplex is an AU base pair.

In one embodiment, the sense strand comprises at least 17 contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from the nucleotide sequence of 5′-GACGCCACGCAUGCUGUGUGU-3′(SEQ ID NO: 119).

In one embodiment, the sense strand comprises at least 19 contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from the nucleotide sequence of 5′-GACGCCACGCAUGCUGUGUGU-3′(SEQ ID NO: 119).

In one embodiment, the sense strand comprises or consists of the nucleotide sequence of 5′-GACGCCACGCAUGCUGUGUGU-3′(SEQ ID NO: 119).

In one embodiment, the antisense strand comprises at least 17 contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from the nucleotide sequence of 5′-ACACACAGCAUGCGUGGCGUCAC-3′ (SEQ ID NO: 245).

In one embodiment, the antisense strand comprises at least 19 contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from the nucleotide sequence of 5′-ACACACAGCAUGCGUGGCGUCAC-3′ (SEQ ID NO: 245).

In one embodiment, the antisense strand comprises at least 21 contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from the nucleotide sequence of 5′-ACACACAGCAUGCGUGGCGUCAC-3′ (SEQ ID NO: 245).

In one embodiment, the antisense strand comprises or consists of the nucleotide sequence of 5′-ACACACAGCAUGCGUGGCGUCAC-3′ (SEQ ID NO: 245).

In one embodiment, the sense strand comprises the nucleotide sequence of 5′-GACGCCACGCAUGCUGUGUGU-3′(SEQ ID NO: 119) and the antisense strand comprises the nucleotide sequence of 5′-ACACACAGCAUGCGUGGCGUCAC-3′ (SEQ ID NO: 245).

In one embodiment, the sense strand differs by no more than 3, e.g., 0, 1, 2, or 3, modified nucleotides from the nucleotide sequence of 5′-gsascgccacGfCfAfugcugugugu-3′ (SEQ ID NO:371) wherein a, g, c and u are 2′-O-methyl (2′-OMe) A, G, C, and U respectively; Af, Gf, Cf and Uf are 2′-fluoro A, G, C and U respectively; and s is a phosphorothioate linkage.

In one embodiment, the antisense strand differs by no more than 3, e.g., 0, 1, 2, or 3, modified nucleotides from the nucleotide sequence of 5′-asdCsacdAcdAgcaudGcGfuggcgucsasc-3′ (SEQ ID NO: 497), wherein a, g, c and u are 2′-O-methyl (2′-OMe) A, G, C, and U respectively; Af, Gf, Cf and Uf are 2′-fluoro A, G, C and U respectively; wherein dA, dG, and dC are 2′-deoxyadenosine-3′-phosphate, 2′-deoxyguanosine-3′-phosphate, and 2′-deoxycytidine-3′-phosphate respectively; and s is a phosphorothioate linkage.

In one embodiment, the sense strand comprises the nucleotide sequence of 5′-gsascgccacGfCfAfugcugugugu-3′ (SEQ ID NO: 371) and the antisense strand comprises the nucleotide sequence of 5′-asdCsacdAcdAgcaudGcGfuggcgucsasc-3′ (SEQ ID NO: 497), wherein a, g, c and u are 2′-O-methyl (2′-OMe) A, G, C, and U respectively; Af, Gf, Cf and Uf are 2′-fluoro A, G, C and U respectively; wherein dA, dG, and dC are 2′-deoxyadenosine-3′-phosphate, 2′-deoxyguanosine-3′-phosphate, and 2′-deoxycytidine-3′-phosphate respectively; and s is a phosphorothioate linkage.

In one embodiment, the sense strand comprises the nucleotide sequence of 5′-gsascgccacGfCfAfugcuguguguL96-3′ (SEQ ID NO: 2331) and the antisense strand comprises the nucleotide sequence of 5′-asdCsacdAcdAgcaudGcGfuggcgucsasc-3′ (SEQ ID NO: 497), wherein a, g, c and u are 2′-O-methyl (2′-OMe) A, G, C, and U respectively; Af, Gf, Cf and Uf are 2′-fluoro A, G, C and U respectively; wherein dA, dG, and dC are 2′-deoxyadenosine-3′-phosphate, 2′-deoxyguanosine-3′-phosphate, and 2′-deoxycytidine-3′-phosphate respectively; s is a phosphorothioate linkage, and L96 is N-[tris(GalNAc-alkyl)-amidodecanoyl)]-4-hydroxyprolinol.

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and, wherein X is O.

In one embodiment, the sense strand comprises at least 17 contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from the nucleotide sequence of 5′-CCUUUGGAAUAAAGCUGCCUU-3′ (SEQ ID NO: 844).

In one embodiment, the sense strand comprises at least 19 contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from the nucleotide sequence of 5′-CCUUUGGAAUAAAGCUGCCUU-3′ (SEQ ID NO: 844).

In one embodiment, the sense strand comprises or consists of the nucleotide sequence of 5′-CCUUUGGAAUAAAGCUGCCUU-3′(SEQ ID NO: 844).

In one embodiment, the antisense strand comprises at least 17 contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from the nucleotide sequence of 5′-AAGGCAGCUUUAUUCCAAAGGGC-3′ (SEQ ID NO: 1868).

In one embodiment, the antisense strand comprises at least 19 contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from the nucleotide sequence of 5′-AAGGCAGCUUUAUUCCAAAGGGC-3′ (SEQ ID NO: 1868).

In one embodiment, the antisense strand comprises at least 21 contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from the nucleotide sequence of 5′-AAGGCAGCUUUAUUCCAAAGGGC-3′ (SEQ ID NO: 1868).

In one embodiment, the antisense strand comprises or consists of the nucleotide sequence of 5′-AAGGCAGCUUUAUUCCAAAGGGC-3′ (SEQ ID NO: 1868).

In one embodiment, the sense strand comprises the nucleotide sequence of 5′-CCUUUGGAAUAAAGCUGCCUU-3′(SEQ ID NO: 844) and the antisense strand comprises the nucleotide sequence of 5′-AAGGCAGCUUUAUUCCAAAGGGC-3′ (SEQ ID NO: 1868).

In one embodiment, the sense strand differs by no more than 3, e.g., 0, 1, 2, or 3, modified nucleotides from the nucleotide sequence of 5′-cscsuuugGfaAfUfAfaagcugccuu-3′ (SEQ ID NO: 2095) wherein a, g, c and u are 2′-O-methyl (2′-OMe) A, G, C, and U respectively; Af, Gf, Cf and Uf are 2′-fluoro A, G, C and U respectively; and s is a phosphorothioate linkage.

In one embodiment, the antisense strand differs by no more than 3, e.g., 0, 1, 2, or 3, modified nucleotides from the nucleotide sequence of 5′-asAfsggdCa(G2p)cuuuauUfcCfaaaggsgsc-3′ (SEQ ID NO: 2324), wherein a, g, c and u are 2′-O-methyl (2′-OMe) A, G, C, and U respectively; Af, Gf, Cf and Uf are 2′-fluoro A, G, C and U respectively; wherein G2p is guanosine-2′-phosphate; and s is a phosphorothioate linkage.

In one embodiment, the sense strand comprises the nucleotide sequence of 5′-cscsuuugGfaAfUfAfaagcugccuu-3′ (SEQ ID NO: 2095) and the antisense strand comprises the nucleotide sequence of 5′-asAfsggdCa(G2p)cuuuauUfcCfaaaggsgsc-3′ (SEQ ID NO: 2324), wherein a, g, c and u are 2′-O-methyl (2′-OMe) A, G, C, and U respectively; Af, Gf, Cf and Uf are 2′-fluoro A, G, C and U respectively; wherein G2p is guanosine-2′-phosphate; and s is a phosphorothioate linkage.

In one embodiment, the sense strand comprises the nucleotide sequence of 5′-cscsuuugGfaAfUfAfaagcugccuuL96-3′ (SEQ ID NO: 2333) and the antisense strand comprises the nucleotide sequence of 5′-asAfsggdCa(G2p)cuuuauUfcCfaaaggsgsc-3′ (SEQ ID NO: 2324), wherein a, g, c and u are 2′-O-methyl (2′-OMe) A, G, C, and U respectively; Af, Gf, Cf and Uf are 2′-fluoro A, G, C and U respectively; wherein G2p is guanosine-2′-phosphate; s is a phosphorothioate linkage, and L96 is N-[tris(GalNAc-alkyl)-amidodecanoyl)]-4-hydroxyprolinol.

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and, wherein X is O.

In one embodiment, the sense strand comprises at least 17 contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from the nucleotide sequence of 5′-UCACCUGCUUCUUCUGGUU-3′(SEQ ID NO: 1686).

In one embodiment, the sense strand comprises or consists of the nucleotide sequence of 5′-UCACCUGCUUCUUCUGGUU-3′(SEQ ID NO: 1686).

In one embodiment, the antisense strand comprises at least 17 contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from the nucleotide sequence of 5′-AACCAGAAGAAGCAGGUGA-3′ (SEQ ID NO: 1790).

In one embodiment, the antisense strand comprises or consists of the nucleotide sequence of 5′-AACCAGAAGAAGCAGGUGA-3′ (SEQ ID NO: 1790).

In one embodiment, the sense strand comprises the nucleotide sequence of 5′-UCACCUGCUUCUUCUGGUU-3′(SEQ ID NO: 1686) and the antisense strand comprises the nucleotide sequence of 5′-AACCAGAAGAAGCAGGUGA-3′ (SEQ ID NO:1790).

In one embodiment, the sense strand differs by no more than 3, e.g., 0, 1, 2, or 3, modified nucleotides from the nucleotide sequence of 5′-UfcAfcCfuGfcUfuCfuUfcUfgGfsusUf-3′ (SEQ ID NO: 1974) wherein a, g, c and u are 2′-O-methyl (2′-OMe) A, G, C, and U respectively; Af, Gf, Cf and Uf are 2′-fluoro A, G, C and U respectively; and s is a phosphorothioate linkage.

In one embodiment, the antisense strand differs by no more than 3, e.g., 0, 1, 2, or 3, modified nucleotides from the nucleotide sequence of 5′-asAfscCfaGfaAfgAfaGfcAfgGfusGfsa-3′ (SEQ ID NO: 2203), wherein a, g, c and u are 2′-O-methyl (2′-OMe) A, G, C, and U respectively; Af, Gf, Cf and Uf are 2′-fluoro A, G, C and U respectively; and s is a phosphorothioate linkage.

In one embodiment, the sense strand comprises the nucleotide sequence of 5′-UfcAfcCfuGfcUfuCfuUfcUfgGfsusUf-3′ (SEQ ID NO: 1974) and the antisense strand comprises the nucleotide sequence of 5′-asAfscCfaGfaAfgAfaGfcAfgGfusGfsa-3′ (SEQ ID NO: 2203), wherein a, g, c and u are 2′-O-methyl (2′-OMe) A, G, C, and U respectively; Af, Gf, Cf and Uf are 2′-fluoro A, G, C and U respectively; and s is a phosphorothioate linkage.

In one embodiment, the sense strand comprises the nucleotide sequence of 5′-Q191sUfcAfcCfuGfcUfuCfuUfcUfgGfsusUf-3′ (SEQ ID NO: 2332) and the antisense strand comprises the nucleotide sequence of 5′-asAfscCfaGfaAfgAfaGfcAfgGfusGfsa-3′ (SEQ ID NO: 2203), wherein a, g, c and u are 2′-O-methyl (2′-OMe) A, G, C, and U respectively; Af, Gf, Cf and Uf are 2′-fluoro A, G, C and U respectively; s is a phosphorothioate linkage, and Q191 is N-[tris(GalNAc-alkyl)-amidododecanoyl]-(S)-pyrrolidin-3-ol-phosphorothioate (p-C12-(GalNAc-alkyl)3).

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In another embodiment, the RNAi agent is a pharmaceutically acceptable salt thereof. “Pharmaceutically acceptable salts” of each of RNAi agents herein include, but are not limited to, a sodium salt, a calcium salt, a lithium salt, a potassium salt, an ammonium salt, a magnesium salt, an mixtures thereof. One skilled in the art will appreciate that the RNAi agent, when provided as a polycationic salt having one cation per free acid group of the optionally modified phosophodiester backbone and/or any other acidic modifications (e.g., 5′-terminal phosphonate groups). For example, an oligonucleotide of “n” nucleotides in length contains n−1 optionally modified phosophodiesters, so that an oligonucleotide of 21 nt in length may be provided as a salt having up to 20 cations (e.g, 20 sodium cations). Similarly, an RNAi agents having a sense strand of 21 nt in length and an antisense strand of 23 nt in length may be provided as a salt having up to 42 cations (e.g., 42 sodium cations). In the preceding example, where the RNAi agent also includes a 5′-terminal phosphate or a 5′-terminal vinylphosphonate group, the RNAi agent may be provided as a salt having up to 44 cations (e.g., 44 sodium cations).

The present invention also provides cells containing any of the dsRNA agents of the invention and pharmaceutical compositions comprising any of the dsRNA agents of the invention.

The pharmaceutical composition of the invention may include dsRNA agent in an unbuffered solution, e.g., saline or water, or the pharmaceutical composition of the invention may include the dsRNA agent is in a buffer solution, e.g., a buffer solution comprising acetate, citrate, prolamine, carbonate, or phosphate or any combination thereof; or phosphate buffered saline (PBS).

In one aspect, the present invention provides a method of inhibiting expression of a Transmembrane protease, serine 6 (TMPRSS6) gene in a cell. The method includes contacting the cell with any of the dsRNAs of the invention or any of the pharmaceutical compositions of the invention, thereby inhibiting expression of the TMPRSS6 gene in the cell.

In one embodiment, the cell is within a subject, e.g., a human subject, e.g., a subject having a Transmembrane protease, serine 6 (TMPRSS6)-associated disorder, such as a disorder associated with iron overload and/or a disorder of ineffective erythropoiesis, e.g., hereditary hemochromatosis, β-thalassemia (e.g., β-thalassemia major and β-thalassemia intermedia), polycythemia vera, myelodysplastic syndrome, congenital dyserythropoietic anemias, pyruvate kinase deficiency, erythropoietic porphyria, Parkinson's Disease, Alzheimer's Disease or Friedreich's Ataxia.

In some embodiments, the TMPRSS6-associated disorder is β-thalassemia. In one embodiment, the TMPRSS6-associated disorder is β-thalassemia major. In another embodiment, the TMPRSS6-associated disorder is β-thalassemia intermedia. In some embodiments, the TMPRSS6-associated disorder is polycythemia vera.

In certain embodiments, the TMPRSS6 expression is inhibited by at least about 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95%. In one embodiment, inhibiting expression of TMPRSS6 decreases TMPRSS6 protein level in serum of the subject by at least 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95%.

In certain embodiments, contacting the cell with the dsRNA agent increases the expression of hepcidin by at least 50%, 60%, 70%, 80%, 90%, or 95%. In one embodiment, increasing expression of hepicidin increases hepicidin protein level in serum of the subject by at least 50%, 60%, 70%, 80%, 90%, or 95%.

In one aspect, the present invention provides a method of treating a subject having a disorder that would benefit from reduction in Transmembrane protease, serine 6 (TMPRSS6) expression. The method includes administering to the subject a therapeutically effective amount of any of the dsRNAs of the invention or any of the pharmaceutical compositions of the invention, thereby treating the subject having the disorder that would benefit from reduction in TMPRSS6 expression.

In another aspect, the present invention provides a method of preventing at least one symptom in a subject having a disorder that would benefit from reduction in Transmembrane protease, serine 6 (TMPRSS6) expression. The method includes administering to the subject a prophylactically effective amount of any of the dsRNAs of the invention or any of the pharmaceutical compositions of the invention, thereby preventing at least one symptom in the subject having the disorder that would benefit from reduction in TMPRSS6 expression.

In certain embodiments, the disorder is a Transmembrane protease, serine 6 (TMPRSS6)-associated disorder, e.g., a disorder associated with iron overload and/or a disorder of ineffective erythropoiesis, e.g., hereditary hemochromatosis, β-thalassemia (e.g., β-thalassemia major and β-thalassemia intermedia), polycythemia vera, myelodysplastic syndrome, congenital dyserythropoietic anemias, pyruvate kinase deficiency, erythropoietic porphyria, Parkinson's Disease, Alzheimer's Disease or Friedreich's Ataxia.

In certain embodiments, administration of the dsRNA to the subject causes a decrease in the iron level, ferritin level and/or transferrin saturation level and/or a decrease in TMPRSS6 protein accumulation in the subject. In some embodiments, administration of the dsRNA to the subject causes an increase in the hemoglobin level and/or the hematocrit level in the subject.

In a further aspect, the present invention also provides methods of inhibiting the expression of TMPRSS6 in a subject. The methods include administering to the subject a therapeutically effective amount of any of the dsRNAs provided herein, thereby inhibiting the expression of TMPRSS6 in the subject.

In one embodiment, the subject is human.

In one embodiment, the dsRNA agent is administered to the subject at a dose of about 0.01 mg/kg to about 50 mg/kg.

In one embodiment, the dsRNA agent is administered to the subject subcutaneously or intravenously.

In one embodiment, the methods of the invention include further determining the level of TMPRSS6 in a sample(s) from the subject.

In one embodiment, the level of TMPRSS6 in the subject sample(s) is a TMPRSS6 protein level in a blood, serum or liver sample(s).

In one embodiment, the methods of the invention include further determining the level of iron and/or hepcidin in a sample(s) from the subject.

In certain embodiments, the methods of the invention further comprise administering to the subject an additional therapeutic agent. In one embodiment, the methods of the invention further comprise administering an iron chelator, e.g., deferiprone, deferoxamine, and deferasirox, to a subject.

The present invention also provides kits comprising any of the dsRNAs of the invention or any of the pharmaceutical compositions of the invention, and optionally, instructions for use. In one embodiment, the invention provides a kit for performing a method of inhibiting expression of TMPRSS6 gene in a cell by contacting a cell with a double stranded RNAi agent of the invention in an amount effective to inhibit expression of the TMPRSS6 in the cell. The kit comprises an RNAi agent and instructions for use and, optionally, means for administering the RNAi agent to a subject.

The present invention also provide an RNA-induced silencing complex (RISC) comprising an antisense strand of any of the dsRNA agents of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic depicting the study plan to determine the efficacy of the dsRNA agents disclosed herein in vivo in Cynomolgus monkeys.

FIG. 2 is a graph showing the percent of serum TMPRSS6 mRNA remaining in Cynomolgous monkeys (n=3 per group) subcutaneously administered a single 3 mg/kg or 10 mg/kg dose of the indicated dsRNA duplexes at Days 21, 22, 57, and 85 post-dose. TMPRSS6 mRNA levels are shown relative to control levels obtained from Cynomolgous monkeys administered PBS as a control.

FIG. 3 is a graph showing the plasma iron levels, as a percent of predose levels, in Cynomolgous monkeys (n=3 per group) subcutaneously administered a single 3 mg/kg or 10 mg/kg dose of the indicated dsRNA duplexes at Days 1, 8, 15, 22, 29, 36, 43, 50, 57, 64, 71, 78, and 85 post-dose.

FIG. 4 is a graph showing the percent transferrin saturation levels in Cynomolgous monkeys (n=3 per group) subcutaneously administered a single 3 mg/kg or 10 mg/kg dose of the indicated dsRNA duplexes at Days 1, 8, 15, 22, 29, 36, 43, 50, 57, 64, 71, 78, and 85 post-dose.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides iRNA compositions which effect the RNA-induced silencing complex (RISC)-mediated cleavage of RNA transcripts of a Transmembrane protease, serine 6 (TMPRSS6) gene. The gene may be within a cell, e.g., a cell within a subject, such as a human. The use of these iRNAs enables the targeted degradation of mRNAs of the corresponding gene (TMPRSS6) in mammals.

The iRNAs of the invention have been designed to target the human Transmembrane protease, serine 6 (TMPRSS6) gene, including portions of the gene that are conserved in the TMPRSS6 orthologs of other mammalian species. Without intending to be limited by theory, it is believed that a combination or sub-combination of the foregoing properties and the specific target sites or the specific modifications in these iRNAs confer to the iRNAs of the invention improved efficacy, stability, potency, durability, and safety.

Accordingly, the present invention provides methods for treating and preventing a Transmembrane protease, serine 6 (TMPRSS6)-associated disorder, e.g., a disorder associated with iron overload and/or a disorder of ineffective erythropoiesis, e.g., hereditary hemochromatosis, β-thalassemia (e.g., β-thalassemia major and β-thalassemia intermedia), polycythemia vera, myelodysplastic syndrome, congenital dyserythropoietic anemias, pyruvate kinase deficiency, using iRNA compositions which effect the RNA-induced silencing complex (RISC)-mediated cleavage of RNA transcripts of a TMPRSS6 gene.

The iRNAs of the invention include an RNA strand (the antisense strand) having a region which is up to about 30 nucleotides or less in length, e.g., 19-30, 19-29, 19-28, 19-27, 19-26, 19-25, 19-24, 19-23, 19-22, 19-21, 19-20, 20-30, 20-29, 20-28, 20-27, 20-26, 20-25, 20-24, 20-23, 20-22, 20-21, 21-30, 21-29, 21-28, 21-27, 21-26, 21-25, 21-24, 21-23, or 21-22 nucleotides in length, which region is substantially complementary to at least part of an mRNA transcript of a TMPRSS6 gene.

In certain embodiments, one or both of the strands of the double stranded RNAi agents of the invention is up to 66 nucleotides in length, e.g., 36-66, 26-36, 25-36, 31-60, 22-43, 27-53 nucleotides in length, with a region of at least 19 contiguous nucleotides that is substantially complementary to at least a part of an mRNA transcript of a TMPRSS6 gene. In some embodiments, such iRNA agents having longer length antisense strands may, for example, include a second RNA strand (the sense strand) of 20-60 nucleotides in length wherein the sense and antisense strands form a duplex of 18-30 contiguous nucleotides.

The use of iRNAs of the invention enables the targeted degradation of mRNAs of the corresponding gene (TMPRSS6 gene) in mammals Using in vitro assays, the present inventors have demonstrated that iRNAs targeting a TMPRSS6 gene can potently mediate RNAi, resulting in significant inhibition of expression of a TMPRSS6 gene. Thus, methods and compositions including these iRNAs are useful for treating a subject having a TMPRSS6-associated disorder, e.g., a disorder associated with iron overload and/or a disorder of ineffective erythropoiesis, e.g., hereditary hemochromatosis, β-thalassemia (e.g., β-thalassemia major and β-thalassemia intermedia), polycythemia vera, myelodysplastic syndrome, congenital dyserythropoietic anemias, pyruvate kinase deficiency, erythropoietic porphyria, Parkinson's Disease, Alzheimer's Disease or Friedreich's Ataxia.

Accordingly, the present invention provides methods and combination therapies for treating a subject having a disorder that would benefit from inhibiting or reducing the expression of a TMPRSS6 gene, e.g., a Transmembrane protease, serine 6 (TMPRSS6)-associated disease, such as a disorder associated with iron overload and/or a disorder of ineffective erythropoiesis, e.g., hereditary hemochromatosis, β-thalassemia (e.g., β-thalassemia major and β-thalassemia intermedia), polycythemia vera, myelodysplastic syndrome, congenital dyserythropoietic anemias, pyruvate kinase deficiency, using iRNA compositions which effect the RNA-induced silencing complex (RISC)-mediated cleavage of RNA transcripts of a TMPRSS6 gene.

The present invention also provides methods for preventing at least one symptom in a subject having a disorder that would benefit from inhibiting or reducing the expression of a TMPRSS6 gene, e.g., a disorder associated with iron overload and/or a disorder of ineffective erythropoiesis, e.g., hereditary hemochromatosis, β-thalassemia (e.g., β-thalassemia major and β-thalassemia intermedia), polycythemia vera, myelodysplastic syndrome, congenital dyserythropoietic anemias, pyruvate kinase deficiency, erythropoietic porphyria, Parkinson's Disease, Alzheimer's Disease or Friedreich's Ataxia.

The following detailed description discloses how to make and use compositions containing iRNAs to inhibit the expression of a TMPRSS6 gene as well as compositions, uses, and methods for treating subjects that would benefit from inhibition and/or reduction of the expression of a TMPRSS6 gene, e.g., subjects susceptible to or diagnosed with a TMPRSS6-associated disorder.

I. Definitions

In order that the present invention may be more readily understood, certain terms are first defined. In addition, it should be noted that whenever a value or range of values of a parameter are recited, it is intended that values and ranges intermediate to the recited values are also intended to be part of this invention.

The articles “a” and “an” are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, “an element” means one element or more than one element, e.g., a plurality of elements.

The term “including” is used herein to mean, and is used interchangeably with, the phrase “including but not limited to”.

The term “or” is used herein to mean, and is used interchangeably with, the term “and/or,” unless context clearly indicates otherwise. For example, “sense strand or antisense strand” is understood as “sense strand or antisense strand or sense strand and antisense strand.”

The term “about” is used herein to mean within the typical ranges of tolerances in the art. For example, “about” can be understood as about 2 standard deviations from the mean. In certain embodiments, about means+10%. In certain embodiments, about means+5%. When about is present before a series of numbers or a range, it is understood that “about” can modify each of the numbers in the series or range.

The term “at least”, “no less than”, or “or more” prior to a number or series of numbers is understood to include the number adjacent to the term “at least”, and all subsequent numbers or integers that could logically be included, as clear from context. For example, the number of nucleotides in a nucleic acid molecule must be an integer. For example, “at least 19 nucleotides of a 21 nucleotide nucleic acid molecule” means that 19, 20, or 21 nucleotides have the indicated property. When at least is present before a series of numbers or a range, it is understood that “at least” can modify each of the numbers in the series or range.

As used herein, “no more than” or “or less” is understood as the value adjacent to the phrase and logical lower values or integers, as logical from context, to zero. For example, a duplex with an overhang of “no more than 2 nucleotides” has a 2, 1, or 0 nucleotide overhang. When “no more than” is present before a series of numbers or a range, it is understood that “no more than” can modify each of the numbers in the series or range. As used herein, ranges include both the upper and lower limit.

As used herein, methods of detection can include determination that the amount of analyte present is below the level of detection of the method.

In the event of a conflict between an indicated target site and the nucleotide sequence for a sense or antisense strand, the indicated sequence takes precedence.

In the event of a conflict between a sequence and its indicated site on a transcript or other sequence, the nucleotide sequence recited in the specification takes precedence.

As used herein, “Transmembrane protease, serine 6,” used interchangeably with the term “TMPRSS6,” refers to the type II plasma membrane serine protease (TTSP) gene or protein. TMPRSS6 is also known as matriptase-2, IRIDA (iron refractory iron-deficiency anemia), transmembrane protease serine 6, type II transmembrane serine protease 6, and membrane-bound mosaic serine proteinase matriptase-2. TMPRSS6 is a serine protease Type II transmembrane protein of approximately 899 amino acids in length. TMPRSS6 contains multiple domains, e.g., a short endo domain, a transmembrane domain, a sea urchin sperm protein/enteropeptidase domain/agrin (SEA) domain, two complement factor/urchin embryonic growth factor/BMP domains (CUB), three LDL-R class a domains (LDLa), and a trypsin-like serine protease domain with conserved His-Asp-Ser triad (HDS).

The sequence of a human TMPRSS6 mRNA transcript can be found at, for example, GenBank Accession No. GI: 1755203660 (NM_153609.4; SEQ ID NO:1; reverse complement, SEQ ID NO: 2). The sequence of mouse TMPRSS6 mRNA can be found at, for example, GenBank Accession No. GI: 125656151 (NM_027902.2; SEQ ID NO:3; reverse complement, SEQ ID NO: 4). The sequence of rat TMPRSS6 mRNA can be found at, for example, GenBank Accession No. GI: 194474097 (NM_001130556.1; SEQ ID NO:5; reverse complement, SEQ ID NO: 6). The sequence of Macaca fascicularis TMPRSS6 mRNA can be found at, for example, GenBank Accession No. GI: 982272225 (XM_005567384.2; SEQ ID NO: 7; reverse complement, SEQ ID NO: 8). The sequence of Macaca mulatta TMPRSS6 mRNA can be found at, for example, GenBank Accession No. GI: 1622838152 (XM_015150283.2; SEQ ID NO: 9; reverse complement, SEQ ID NO: 10).

Additional examples of TMPRSS6 mRNA sequences are readily available through publicly available databases, e.g., GenBank, UniProt, OMIM, and the Macaca genome project web site.

Further information on TMPRSS6 can be found, for example, at www.ncbi.nlm.nih.gov/gene/?term=TMPRSS6.

The entire contents of each of the foregoing GenBank Accession numbers and the Gene database numbers are incorporated herein by reference as of the date of filing this application.

The term TMPRSS6, as used herein, also refers to variations of the TMPRSS6 gene including variants provided in the SNP database. Numerous seuqnce variations within the TMPRSS6 gene have been identified and may be found at, for example, NCBI dbSNP and UniProt (see, e.g., www.ncbi.nlm.nih.gov/snp/?term=TMPRSS6, the entire contents of which is incorporated herein by reference as of the date of filing this application.

As used herein, “target sequence” refers to a contiguous portion of the nucleotide sequence of an mRNA molecule formed during the transcription of a TMPRSS6 gene, including mRNA that is a product of RNA processing of a primary transcription product. In one embodment, the target portion of the sequence will be at least long enough to serve as a substrate for iRNA-directed cleavage at or near that portion of the nucleotide sequence of an mRNA molecule formed during the transcription of a TMPRSS6 gene.

The target sequence may be from about 19-36 nucleotides in length, e.g., about 19-30 nucleotides in length. For example, the target sequence can be about 19-30 nucleotides, 19-30, 19-29, 19-28, 19-27, 19-26, 19-25, 19-24, 19-23, 19-22, 19-21, 19-20, 20-30, 20-29, 20-28, 20-27, 20-26, 20-25, 20-24, 20-23, 20-22, 20-21, 21-30, 21-29, 21-28, 21-27, 21-26, 21-25, 21-24, 21-23, or 21-22 nucleotides in length. In certain embodiments, the target sequence is 19-23 nucleotides in length, optionally 21-23 nucleotides in length. Ranges and lengths intermediate to the above recited ranges and lengths are also contemplated to be part of the disclosure.

As used herein, the term “strand comprising a sequence” refers to an oligonucleotide comprising a chain of nucleotides that is described by the sequence referred to using the standard nucleotide nomenclature.

“G,” “C,” “A,” “T,” and “U” each generally stand for a nucleotide that contains guanine, cytosine, adenine, thymidine, and uracil as a base, respectively. However, it will be understood that the term “ribonucleotide” or “nucleotide” can also refer to a modified nucleotide, as further detailed below, or a surrogate replacement moiety (see, e.g., Table 1). The skilled person is well aware that guanine, cytosine, adenine, and uracil can be replaced by other moieties without substantially altering the base pairing properties of an oligonucleotide comprising a nucleotide bearing such replacement moiety. For example, without limitation, a nucleotide comprising inosine as its base can base pair with nucleotides containing adenine, cytosine, or uracil. Hence, nucleotides containing uracil, guanine, or adenine can be replaced in the nucleotide sequences of dsRNA featured in the invention by a nucleotide containing, for example, inosine. In another example, adenine and cytosine anywhere in the oligonucleotide can be replaced with guanine and uracil, respectively to form G-U Wobble base pairing with the target mRNA. Sequences containing such replacement moieties are suitable for the compositions and methods featured in the invention.

The terms “iRNA”, “RNAi agent,” “iRNA agent,”, “RNA interference agent” as used interchangeably herein, refer to an agent that contains RNA as that term is defined herein, and which mediates the targeted cleavage of an RNA transcript via an RNA-induced silencing complex (RISC) pathway. iRNA directs the sequence-specific degradation of mRNA through a process known as RNA interference (RNAi). The iRNA modulates, e.g., inhibits, the expression of a TMPRSS6 gene in a cell, e.g., a cell within a subject, such as a mammalian subject.

In one embodiment, an RNAi agent of the invention includes a single stranded RNA that interacts with a target RNA sequence, e.g., a TMPRSS6 target mRNA sequence, to direct the cleavage of the target RNA. Without wishing to be bound by theory it is believed that long double stranded RNA introduced into cells is broken down into siRNA by a Type III endonuclease known as Dicer (Sharp et al. (2001) Genes Dev. 15:485). Dicer, a ribonuclease-III-like enzyme, processes the dsRNA into 19-23 base pair short interfering RNAs with characteristic two base 3′ overhangs (Bernstein, et al., (2001) Nature 409:363). The siRNAs are then incorporated into an RNA-induced silencing complex (RISC) where one or more helicases unwind the siRNA duplex, enabling the complementary antisense strand to guide target recognition (Nykanen, et al., (2001) Cell 107:309). Upon binding to the appropriate target mRNA, one or more endonucleases within the RISC cleave the target to induce silencing (Elbashir, et al., (2001) Genes Dev. 15:188). Thus, in one aspect the invention relates to a single stranded RNA (siRNA) generated within a cell and which promotes the formation of a RISC complex to effect silencing of the target gene, i.e., a TMPRSS6 gene. Accordingly, the term “siRNA” is also used herein to refer to an iRNA as described above.

In certain embodiments, the RNAi agent may be a single-stranded siRNA (ssRNAi) that is introduced into a cell or organism to inhibit a target mRNA. Single-stranded RNAi agents bind to the RISC endonuclease, Argonaute 2, which then cleaves the target mRNA. The single-stranded siRNAs are generally 15-30 nucleotides and are chemically modified. The design and testing of single-stranded siRNAs are described in U.S. Pat. No. 8,101,348 and in Lima et al., (2012) Cell 150:883-894, the entire contents of each of which are hereby incorporated herein by reference. Any of the antisense nucleotide sequences described herein may be used as a single-stranded siRNA as described herein or as chemically modified by the methods described in Lima et al., (2012) Cell 150:883-894.

In certain embodiments, an “iRNA” for use in the compositions, uses, and methods of the invention is a double stranded RNA and is referred to herein as a “double stranded RNA agent,” “double stranded RNA (dsRNA) molecule,” “dsRNA agent,” or “dsRNA”. The term “dsRNA”, refers to a complex of ribonucleic acid molecules, having a duplex structure comprising two anti-parallel and substantially complementary nucleic acid strands, referred to as having “sense” and “antisense” orientations with respect to a target RNA, i.e., a TMPRSS6 gene. In some embodiments of the invention, a double stranded RNA (dsRNA) triggers the degradation of a target RNA, e.g., an mRNA, through a post-transcriptional gene-silencing mechanism referred to herein as RNA interference or RNAi.

In general, the majority of nucleotides of each strand of a dsRNA molecule are ribonucleotides, but as described in detail herein, each or both strands can also include one or more non-ribonucleotides, e.g., a deoxyribonucleotide or a modified nucleotide. In addition, as used in this specification, an “iRNA” may include ribonucleotides with chemical modifications; an iRNA may include substantial modifications at multiple nucleotides. As used herein, the term “modified nucleotide” refers to a nucleotide having, independently, a modified sugar moiety, a modified internucleotide linkage, or modified nucleobase, or any combination thereof. Thus, the term modified nucleotide encompasses substitutions, additions or removal of, e.g., a functional group or atom, to internucleoside linkages, sugar moieties, or nucleobases. The modifications suitable for use in the agents of the invention include all types of modifications disclosed herein or known in the art. Any such modifications, as used in a siRNA type molecule, are encompassed by “iRNA” or “RNAi agent” for the purposes of this specification and claims.

In certain embodiments of the instant disclosure, inclusion of a deoxy-nucleotide if present within an RNAi agent can be considered to constitute a modified nucleotide.

The duplex region may be of any length that permits specific degradation of a desired target RNA through a RISC pathway, and may range from about 19 to 36 base pairs in length, e.g., about 19-30 base pairs in length, for example, about 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, or 36 base pairs in length, such as about 19-30, 19-29, 19-28, 19-27, 19-26, 19-25, 19-24, 19-23, 19-22, 19-21, 19-20, 20-30, 20-29, 20-28, 20-27, 20-26, 20-25, 20-24, 20-23, 20-22, 20-21, 21-30, 21-29, 21-28, 21-27, 21-26, 21-25, 21-24, 21-23, or 21-22 base pairs in length. In certain embodiments, the duplex region is 19-21 base pairs in length, e.g., 21 base pairs in length. Ranges and lengths intermediate to the above recited ranges and lengths are also contemplated to be part of the disclosure.

The two strands forming the duplex structure may be different portions of one larger RNA molecule, or they may be separate RNA molecules. Where the two strands are part of one larger molecule, and therefore are connected by an uninterrupted chain of nucleotides between the 3′-end of one strand and the 5′-end of the respective other strand forming the duplex structure, the connecting RNA chain is referred to as a “hairpin loop.” A hairpin loop can comprise at least one unpaired nucleotide. In some embodiments, the hairpin loop can comprise at least 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 23 or more unpaired nucleotides. In some embodiments, the hairpin loop can be 10 or fewer nucleotides. In some embodiments, the hairpin loop can be 8 or fewer unpaired nucleotides. In some embodiments, the hairpin loop can be 4-10 unpaired nucleotides. In some embodiments, the hairpin loop can be 4-8 nucleotides.

Where the two substantially complementary strands of a dsRNA are comprised by separate RNA molecules, those molecules need not be, but can be covalently connected. Where the two strands are connected covalently by means other than an uninterrupted chain of nucleotides between the 3′-end of one strand and the 5′-end of the respective other strand forming the duplex structure, the connecting structure is referred to as a “linker.” The RNA strands may have the same or a different number of nucleotides. The maximum number of base pairs is the number of nucleotides in the shortest strand of the dsRNA minus any overhangs that are present in the duplex. In addition to the duplex structure, an RNAi may comprise one or more nucleotide overhangs. In one embodiment of the RNAi agent, at least one strand comprises a 3′ overhang of at least 1 nucleotide. In another embodiment, at least one strand comprises a 3′ overhang of at least 2 nucleotides, e.g., 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14, or 15 nucleotides. In other embodiments, at least one strand of the RNAi agent comprises a 5′ overhang of at least 1 nucleotide. In certain embodiments, at least one strand comprises a 5′ overhang of at least 2 nucleotides, e.g., 2, 3, 4, 5, 6, 7, 9, 10, 11, 12, 13, 14, or 15 nucleotides. In still other embodiments, both the 3′ and the 5′ end of one strand of the RNAi agent comprise an overhang of at least 1 nucleotide.

In certain embodiments, an iRNA agent of the invention is a dsRNA, each strand of which comprises 19-23 nucleotides, that interacts with a target RNA sequence, e.g., a TMPRSS6 gene, to direct cleavage of the target RNA.

In some embodiments, an iRNA of the invention is a dsRNA of 24-30 nucleotides that interacts with a target RNA sequence, e.g., a TMPRSS6 target mRNA sequence, to direct the cleavage of the target RNA.

As used herein, the term “nucleotide overhang” refers to at least one unpaired nucleotide that protrudes from the duplex structure of a double stranded iRNA. For example, when a 3′-end of one strand of a dsRNA extends beyond the 5′-end of the other strand, or vice versa, there is a nucleotide overhang. A dsRNA can comprise an overhang of at least one nucleotide; alternatively the overhang can comprise at least two nucleotides, at least three nucleotides, at least four nucleotides, at least five nucleotides or more. A nucleotide overhang can comprise or consist of a nucleotide/nucleoside analog, including a deoxynucleotide/nucleoside. The overhang(s) can be on the sense strand, the antisense strand, or any combination thereof. Furthermore, the nucleotide(s) of an overhang can be present on the 5′-end, 3′-end, or both ends of either an antisense or sense strand of a dsRNA.

In one embodiment, the antisense strand of a dsRNA has a 1-10 nucleotide, e.g., a 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 nucleotide, overhang at the 3′-end or the 5′-end. In one embodiment, the sense strand of a dsRNA has a 1-10 nucleotide, e.g., a 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 nucleotide, overhang at the 3′-end or the 5′-end. In another embodiment, one or more of the nucleotides in the overhang is replaced with a nucleoside thiophosphate.

In certain embodiments, the antisense strand of a dsRNA has a 1-10 nucleotide, e.g., 0-3, 1-3, 2-4, 2-5, 4-10, 5-10, e.g., a 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 nucleotide, overhang at the 3′-end or the 5′-end. In one embodiment, the sense strand of a dsRNA has a 1-10 nucleotide, e.g., a 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 nucleotide, overhang at the 3′-end or the 5′-end. In another embodiment, one or more of the nucleotides in the overhang is replaced with a nucleoside thiophosphate.

In certain embodiments, the antisense strand of a dsRNA has a 1-10 nucleotides, e.g., a 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 nucleotide, overhang at the 3′-end or the 5′-end. In certain embodiments, the overhang on the sense strand or the antisense strand, or both, can include extended lengths longer than 10 nucleotides, e.g., 1-30 nucleotides, 2-30 nucleotides, 10-30 nucleotides, 10-25 nucleotides, 10-20 nucleotides, or 10-15 nucleotides in length. In certain embodiments, an extended overhang is on the sense strand of the duplex. In certain embodiments, an extended overhang is present on the 3′ end of the sense strand of the duplex. In certain embodiments, an extended overhang is present on the 5′ end of the sense strand of the duplex. In certain embodiments, an extended overhang is on the antisense strand of the duplex. In certain embodiments, an extended overhang is present on the 3′end of the antisense strand of the duplex. In certain embodiments, an extended overhang is present on the 5′end of the antisense strand of the duplex. In certain embodiments, one or more of the nucleotides in the extended overhang is replaced with a nucleoside thiophosphate. In certain embodiments, the overhang includes a self-complementary portion such that the overhang is capable of forming a hairpin structure that is stable under physiological conditions.

“Blunt” or “blunt end” means that there are no unpaired nucleotides at that end of the double stranded RNA agent, i.e., no nucleotide overhang. A “blunt ended” double stranded RNA agent is double stranded over its entire length, i.e., no nucleotide overhang at either end of the molecule. The RNAi agents of the invention include RNAi agents with no nucleotide overhang at one end (i.e., agents with one overhang and one blunt end) or with no nucleotide overhangs at either end. Most often such a molecule will be double-stranded over its entire length.

The term “antisense strand” or “guide strand” refers to the strand of an iRNA, e.g., a dsRNA, which includes a region that is substantially complementary to a target sequence, e.g., a TMPRSS6 mRNA.

As used herein, the term “region of complementarity” refers to the region on the antisense strand that is substantially complementary to a sequence, for example a target sequence, e.g., a TMPRSS6 nucleotide sequence, as defined herein. Where the region of complementarity is not fully complementary to the target sequence, the mismatches can be in the internal or terminal regions of the molecule. Generally, the most tolerated mismatches are in the terminal regions, e.g., within 5, 4, or 3 nucleotides of the 5′- or 3′-end of the iRNA. In some embodiments, a double stranded RNA agent of the invention includes a nucleotide mismatch in the antisense strand. In some embodiments, the antisense strand of the double stranded RNA agent of the invention includes no more than 4 mismatches with the target mRNA, e.g., the antisense strand includes 4, 3, 2, 1, or 0 mismatches with the target mRNA. In some embodiments, the antisense strand double stranded RNA agent of the invention includes no more than 4 mismatches with the sense strand, e.g., the antisense strand includes 4, 3, 2, 1, or 0 mismatches with the sense strand. In some embodiments, a double stranded RNA agent of the invention includes a nucleotide mismatch in the sense strand. In some embodiments, the sense strand of the double stranded RNA agent of the invention includes no more than 4 mismatches with the antisense strand, e.g., the sense strand includes 4, 3, 2, 1, or 0 mismatches with the antisense strand. In some embodiments, the nucleotide mismatch is, for example, within 5, 4, 3 nucleotides from the 3′-end of the iRNA. In another embodiment, the nucleotide mismatch is, for example, in the 3′-terminal nucleotide of the iRNA agent. In some embodiments, the mismatch(s) is not in the seed region.

Thus, an RNAi agent as described herein can contain one or more mismatches to the target sequence. In one embodiment, an RNAi agent as described herein contains no more than 3 mismatches (i.e., 3, 2, 1, or 0 mismatches). In one embodiment, an RNAi agent as described herein contains no more than 2 mismatches. In one embodiment, an RNAi agent as described herein contains no more than 1 mismatch. In one embodiment, an RNAi agent as described herein contains 0 mismatches. In certain embodiments, if the antisense strand of the RNAi agent contains mismatches to the target sequence, the mismatch can optionally be restricted to be within the last 5 nucleotides from either the 5′- or 3′-end of the region of complementarity. For example, in such embodiments, for a 23 nucleotide RNAi agent, the strand which is complementary to a region of a TMPRSS6 gene, generally does not contain any mismatch within the central 13 nucleotides. The methods described herein or methods known in the art can be used to determine whether an RNAi agent containing a mismatch to a target sequence is effective in inhibiting the expression of a TMPRSS6 gene. Consideration of the efficacy of RNAi agents with mismatches in inhibiting expression of a TMPRSS6 gene is important, especially if the particular region of complementarity in a TMPRSS6 gene is known to have polymorphic sequence variation within the population.

The term “sense strand” or “passenger strand” as used herein, refers to the strand of an iRNA that includes a region that is substantially complementary to a region of the antisense strand as that term is defined herein.

As used herein, “substantially all of the nucleotides are modified” are largely but not wholly modified and can include not more than 5, 4, 3, 2, or 1 unmodified nucleotides.

As used herein, the term “cleavage region” refers to a region that is located immediately adjacent to the cleavage site. The cleavage site is the site on the target at which cleavage occurs. In some embodiments, the cleavage region comprises three bases on either end of, and immediately adjacent to, the cleavage site. In some embodiments, the cleavage region comprises two bases on either end of, and immediately adjacent to, the cleavage site. In some embodiments, the cleavage site specifically occurs at the site bound by nucleotides 10 and 11 of the antisense strand, and the cleavage region comprises nucleotides 11, 12 and 13.

As used herein, and unless otherwise indicated, the term “complementary,” when used to describe a first nucleotide sequence in relation to a second nucleotide sequence, refers to the ability of an oligonucleotide or polynucleotide comprising the first nucleotide sequence to hybridize and form a duplex structure under certain conditions with an oligonucleotide or polynucleotide comprising the second nucleotide sequence, as will be understood by the skilled person. Such conditions can, for example, be stringent conditions, where stringent conditions can include: 400 mM NaCl, 40 mM PIPES pH 6.4, 1 mM EDTA, 50° C. or 70° C. for 12-16 hours followed by washing (see, e.g., “Molecular Cloning: A Laboratory Manual, Sambrook, et al. (1989) Cold Spring Harbor Laboratory Press). Other conditions, such as physiologically relevant conditions as can be encountered inside an organism, can apply. The skilled person will be able to determine the set of conditions most appropriate for a test of complementarity of two sequences in accordance with the ultimate application of the hybridized nucleotides.

Complementary sequences within an iRNA, e.g., within a dsRNA as described herein, include base-pairing of the oligonucleotide or polynucleotide comprising a first nucleotide sequence to an oligonucleotide or polynucleotide comprising a second nucleotide sequence over the entire length of one or both nucleotide sequences. Such sequences can be referred to as “fully complementary” with respect to each other herein. However, where a first sequence is referred to as “substantially complementary” with respect to a second sequence herein, the two sequences can be fully complementary, or they can form one or more, but generally not more than 5, 4, 3, or 2 mismatched base pairs upon hybridization for a duplex up to 30 base pairs, while retaining the ability to hybridize under the conditions most relevant to their ultimate application, e.g., inhibition of gene expression, in vitro or in vivo. However, where two oligonucleotides are designed to form, upon hybridization, one or more single stranded overhangs, such overhangs shall not be regarded as mismatches with regard to the determination of complementarity. For example, a dsRNA comprising one oligonucleotide 21 nucleotides in length and another oligonucleotide 23 nucleotides in length, wherein the longer oligonucleotide comprises a sequence of 21 nucleotides that is fully complementary to the shorter oligonucleotide, can yet be referred to as “fully complementary” for the purposes described herein.

“Complementary” sequences, as used herein, can also include, or be formed entirely from, non-Watson-Crick base pairs or base pairs formed from non-natural and modified nucleotides, in so far as the above requirements with respect to their ability to hybridize are fulfilled. Such non-Watson-Crick base pairs include, but are not limited to, G:U Wobble or Hoogsteen base pairing.

The terms “complementary,” “fully complementary” and “substantially complementary” herein can be used with respect to the base matching between the sense strand and the antisense strand of a dsRNA, or between two oligonucletoides or polynucleotides, such as the antisense strand of a double stranded RNA agent and a target sequence, as will be understood from the context of their use.

As used herein, a polynucleotide that is “substantially complementary to at least part of” a messenger RNA (mRNA) refers to a polynucleotide that is substantially complementary to a contiguous portion of the mRNA of interest (e.g., an mRNA encoding a TMPRSS6 gene). For example, a polynucleotide is complementary to at least a part of a TMPRSS6 mRNA if the sequence is substantially complementary to a non-interrupted portion of an mRNA encoding a TMPRSS6 gene.

Accordingly, in some embodiments, the antisense polynucleotides disclosed herein are fully complementary to the target TMPRSS6 sequence. In other embodiments, the antisense polynucleotides disclosed herein are substantially complementary to the target TMPRSS6 sequence and comprise a contiguous nucleotide sequence which is at least 80% complementary over its entire length to the equivalent region of the nucleotide sequence of any one of SEQ ID NOs:1, 3, 5, 7, or 9, or a fragment of any one of SEQ ID NOs:1, 3, 5, 7, or 9, such as about 85%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% complementary.

In some embodiments, the antisense polynucleotides disclosed herein are substantially complementary to a fragment of a target TMPRSS6 sequence and comprise a contiguous nucleotide sequence which is at least 80% complementary over its entire length to a fragment of SEQ ID NO: 1 selected from the group of nucleotides 187-210; 227-254; 322-363; 362-390; 398-420; 404-429; 410-435; 439-461; 443-467; 448-474; 460-483; 466-488; 496-519; 519-542; 526-548; 557-593; 641-671; 652-676; 687-713; 725-762; 757-794; 886-908; 921-951; 956-987; 1051-1082; 1233-1269; 1279-1313; 1313-1341; 1327-1351; 1415-1439; 1447-1480; 1464-1486; 1486-1509; 1559-1589; 1571-1595; 1579-1609; 1707-1735; 1738-1764; 1806-1828; 1864-1886; 1934-1966; 1967-1991; 2008-2031; 2015-2043; 2042-2072; 2287-2311; 2297-2354; 2336-2361; 2360-2384; 2416-2438; 2481-2510; 2496-2527; 2526-2558; 2665-2693; 2693-2719; 2707-2729; 2799-2821; 2851-2874; 2971-2999; 2981-3006; and 3155-3195 of SEQ ID NO: 1, such as about 85%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, or about 99% complementary.

In other embodiments, the antisense polynucleotides disclosed herein are substantially complementary to the target TMPRSS6 sequence and comprise a contiguous nucleotide sequence which is at least about 80% complementary over its entire length to any one of the sense strand nucleotide sequences in any one of any one of Tables 2-7, or a fragment of any one of the sense strand nucleotide sequences in any one of Tables 2-7, such as about 85%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, or 100% complementary.

In one embodiment, an RNAi agent of the disclosure includes a sense strand that is substantially complementary to an antisense polynucleotide which, in turn, is the same as a target TMPRSS6 sequence, and wherein the sense strand polynucleotide comprises a contiguous nucleotide sequence which is at least about 80% complementary over its entire length to the equivalent region of the nucleotide sequence of SEQ ID NOs: 2, 4, 6, 8, or 10, or a fragment of any one of SEQ ID NOs:2, 4, 6, 8, or 10, such as about 85%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, or 100% complementary.

In some embodiments, an iRNA of the invention includes a sense strand that is substantially complementary to an antisense polynucleotide which, in turn, is complementary to a target TMPRSS6 sequence, and wherein the sense strand polynucleotide comprises a contiguous nucleotide sequence which is at least about 80% complementary over its entire length to any one of the antisense strand nucleotide sequences in any one of any one of Tables 2-7, or a fragment of any one of the antisense strand nucleotide sequences in any one of Tables 2-7, such as about 85%, about 90%, about 91%, about 92%, about 93%, about 94%, about 95%, about 96%, about 97%, about 98%, about 99%, or 100% complementary.

In certain embodiments, the sense and antisense strands are selected from any one of duplexes AD-1556360, AD-1571158, AD-1571033, AD-1554875, AD-1571160, AD-1555117, AD-1554911, and AD-1556915.

In certain embodiments, the sense and antisense strands are selected from any one of duplexes AD-1556360, AD-1571158, and AD-1571033.

In general, an “iRNA” includes ribonucleotides with chemical modifications. Such modifications may include all types of modifications disclosed herein or known in the art. Any such modifications, as used in a dsRNA molecule, are encompassed by “iRNA” for the purposes of this specification and claims.

In certain embodiments of the instant disclosure, inclusion of a deoxy-nucleotide if present within an RNAi agent can be considered to constitute a modified nucleotide.

In an aspect of the invention, an agent for use in the methods and compositions of the invention is a single-stranded antisense oligonucleotide molecule that inhibits a target mRNA via an antisense inhibition mechanism. The single-stranded antisense oligonucleotide molecule is complementary to a sequence within the target mRNA. The single-stranded antisense oligonucleotides can inhibit translation in a stoichiometric manner by base pairing to the mRNA and physically obstructing the translation machinery, see Dias, N. et al., (2002) Mol Cancer Ther 1:347-355. The single-stranded antisense oligonucleotide molecule may be about 14 to about 30 nucleotides in length and have a sequence that is complementary to a target sequence. For example, the single-stranded antisense oligonucleotide molecule may comprise a sequence that is at least about 14, 15, 16, 17, 18, 19, 20, or more contiguous nucleotides from any one of the antisense sequences described herein.

The phrase “contacting a cell with an iRNA,” such as a dsRNA, as used herein, includes contacting a cell by any possible means. Contacting a cell with an iRNA includes contacting a cell in vitro with the iRNA or contacting a cell in vivo with the iRNA. The contacting may be done directly or indirectly. Thus, for example, the iRNA may be put into physical contact with the cell by the individual performing the method, or alternatively, the iRNA may be put into a situation that will permit or cause it to subsequently come into contact with the cell.

Contacting a cell in vitro may be done, for example, by incubating the cell with the iRNA. Contacting a cell in vivo may be done, for example, by injecting the iRNA into or near the tissue where the cell is located, or by injecting the iRNA into another area, e.g., the bloodstream or the subcutaneous space, such that the agent will subsequently reach the tissue where the cell to be contacted is located. For example, the iRNA may contain or be coupled to a ligand, e.g., GalNAc, that directs the iRNA to a site of interest, e.g., the liver. Combinations of in vitro and in vivo methods of contacting are also possible. For example, a cell may also be contacted in vitro with an iRNA and subsequently transplanted into a subject.

In certain embodiments, contacting a cell with an iRNA includes “introducing” or “delivering the iRNA into the cell” by facilitating or effecting uptake or absorption into the cell. Absorption or uptake of an iRNA can occur through unaided diffusion or active cellular processes, or by auxiliary agents or devices. Introducing an iRNA into a cell may be in vitro or in vivo. For example, for in vivo introduction, iRNA can be injected into a tissue site or administered systemically. In vitro introduction into a cell includes methods known in the art such as electroporation and lipofection. Further approaches are described herein below or are known in the art.

The term “lipid nanoparticle” or “LNP” is a vesicle comprising a lipid layer encapsulating a pharmaceutically active molecule, such as a nucleic acid molecule, e.g., an iRNA or a plasmid from which an iRNA is transcribed. LNPs are described in, for example, U.S. Pat. Nos. 6,858,225, 6,815,432, 8,158,601, and 8,058,069, the entire contents of which are hereby incorporated herein by reference.

As used herein, a “subject” is an animal, such as a mammal, including a primate (such as a human, a non-human primate, e.g., a monkey, and a chimpanzee), a non-primate (such as a cow, a pig, a horse, a goat, a rabbit, a sheep, a hamster, a guinea pig, a cat, a dog, a rat, or a mouse), or a bird that expresses the target gene, either endogenously or heterologously. In an embodiment, the subject is a human, such as a human being treated or assessed for a disease or disorder that would benefit from reduction in TMPRSS6 expression; a human at risk for a disease or disorder that would benefit from reduction in TMPRSS6 expression; a human having a disease or disorder that would benefit from reduction in TMPRSS6 expression; or human being treated for a disease or disorder that would benefit from reduction in TMPRSS6 expression as described herein. In some embodiments, the subject is a female human. In other embodiments, the subject is a male human. In one embodiment, the subject is an adult subject. In another embodiment, the subject is a pediatric subject.

As used herein, the terms “treating” or “treatment” refer to a beneficial or desired result, such as reducing at least one sign or symptom of a TMPRSS6-associated disorder in a subject. Treatment also includes a reduction of one or more sign or symptoms associated with unwanted TMPRSS6 expression; diminishing the extent of unwanted TMPRSS6 activation or stabilization; amelioration or palliation of unwanted TMPRSS6 activation or stabilization. “Treatment” can also mean prolonging survival as compared to expected survival in the absence of treatment. The term “lower” in the context of the level of TMPRSS6 in a subject or a disease marker or symptom refers to a statistically significant decrease in such level. The decrease can be, for example, at least 10%, 15%, 20%, 25%, 30%, %, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or more. In certain embodiments, a decrease is at least 20%. In certain embodiments, the decrease is at least 50% in a disease marker, e.g., protein or gene expression level. “Lower” in the context of the level of TMPRSS6 in a subject is a decrease to a level accepted as within the range of normal for an individual without such disorder. In certain embodiments, “lower” is the decrease in the difference between the level of a marker or symptom for a subject suffering from a disease and a level accepted within the range of normal for an individual, e.g., the level of decrease in bodyweight between an obese individual and an individual having a weight accepted within the range of normal.

As used herein, “prevention” or “preventing,” when used in reference to a disease, disorder or condition thereof, may be treated or ameliorated by a reduction in expression of a TMPRSS6 gene, refers to a reduction in the likelihood that a subject will develop a symptom associated with such a disease, disorder, or condition, e.g., a symptom of unwanted or excessive TMPRSS6 expression, such as elevated iron levels or iron dyregulation. The likelihood of developing elevated iron levels or iron dyregulation is reduced, for example, when an individual having one or more risk factors for elevated iron levels or iron dyregulation either fails to develop elevated iron levels or iron dyregulation, or develops elevated iron levels or iron dyregulation with less severity relative to a population having the same risk factors and not receiving treatment as described herein. The failure to develop a disease, disorder or condition, or the reduction in the development of a symptom associated with such a disease, disorder or condition (e.g., by at least about 10% on a clinically accepted scale for that disease or disorder), or the exhibition of delayed symptoms delayed (e.g., by days, weeks, months or years) is considered effective prevention.

As used herein, the term “Transmembrane protease, serine 6-associated disease” or “TMPRSS6-associated disease,” is a disease or disorder that is caused by, or associated with TMPRSS6 gene expression or TMPRSS6 protein production. The term “TMPRSS6-associated disease” includes a disease, disorder or condition that would benefit from a decrease in TMPRSS6 gene expression, replication, or protein activity.

In some embodiments, the TMPRSS6-associated disease is a disorder associated with iron overload, a condition characterized by elevated iron levels, or iron dysregulation. Iron overload may be caused, for example, by hereditary conditions, by elevated iron uptake from diet, or by excess iron administered parenterally that includes intravenous injection of excess iron, and transfusional iron overload.

In some embodiments, the TMPRSS6-associated disease is a disorder of ineffective erythropoiesis. Ineffective erythropoiesis is an abnormal expansion of the number of erythroid progenitor cells with unproductive synthesis of enucleated erythrocytes, leading to anemia and hypoxia. In particular, an increase in erythroid cells fails to produce a corresponding increase in red blood cells. As a consequence, iron absorption is still increased in response to stress, but the iron is deposited in the organs rather than being used to generate more erythrocytes.

In some embodiments, TMPRSS6-associated disorders include, but are not limited to, hereditary hemochromatosis, idiopathic hemochromatosis, primary hemochromatosis, secondary hemochromatosis, severe juvenile hemochromatosis, neonatal hemochromatosis, sideroblastic anemia, hemolytic anemia, dyserythropoietic anemia, sickle-cell anemia, hemoglobinopathy, thalassemia (e.g., β-thalassemia and α-thalassemia), polycythemia vera, myelodysplastic syndrome, congenital dyserythropoietic anemias, pyruvate kinase deficiency, chronic liver diseases, porphyria cutanea tarda, erythropoietic porphyria, atransferrinemia, hereditary tyrosinemia, cerebrohepatorenal syndrome, idiopathic pulmonary hemosiderosis, renal hemosiderosis.

In some embodiments, TMPRSS6 associated disorders include disorders associated with oral administration of excess iron, transfusional iron overload and intravenous injection of excess iron.

In other embodiments, TMPRSS6-associated disorders also include disorders with symptoms that are associated with or may be caused by iron overload. Such symptoms include increased risk for liver disease (cirrhosis, cancer), heart attack or heart failure, diabetes mellitus, osteoarthritis, osteoporosis, metabolic syndrome, hypothyroidism, hypogonadism, and in some cases premature death. In one embodiment, TMPRSS6-associated disorders include neurodegenerative disorders associated with iron overload and/or iron dysregulation, such as Alzheimer's Disease, Parkinson's Disease, Huntington's Disease, Friedreich's Ataxia, epilepsy and multiple sclerosis. Administration of an iRNA that targets TMPRSS6, e.g., an iRNA described in any one of Tables 2-7 can treat one or more of these symptoms, or prevent the development or progression of a disease or disorder that is aggravated by increased iron levels.

In one embodiment, a TMPRSS6-associated disorder is a β-thalassemia. A β-thalassemia is any one of a group of hereditary disorders characterized by a genetic deficiency in the synthesis of beta-globin chains. In the homozygous state, beta thalassemia (“thalassemia major”) causes severe, transfusion-dependent anemia. In the heterozygous state, the beta thalassemia trait (“thalassemia minor”) causes mild to moderate microcytic anemia. “Thalassemia intermedia” is a β-thalassemia that results in subjects in whom the clinical severity of the disease is somewhere between the mild symptoms of β-thalassemia minor and the β-thalassemia major. Several laboratory tests may be used to help detect and diagnose thalassemia, for example, a complete blood count to determine the number of red blood cells and the number of hemoglobin, blood smear test, hemoglobin electrophoresis, gene sequencing, or iron tests to examine the level of iron, ferritin, unstaturated iron binding capacity, total iron binding capacity, or the transferrin saturation level. The type and relative amounts of hemoglobin present in red blood cells are another indicator for thalassemia. β-thalassemia upsets the balance of beta and alpha hemoglobin chain formation and causes an increase in minor hemoglobin components. So individuals with the β-thalassemia major usually have larger percentages of Hb F. Those with β-thalassemia minor usually have elevated fraction of Hb A2.

In one embodiment, a β-thalassemia is thalassemia major. In another embodiment, a β-thalassemia is thalassemia intermedia.

In some embodiments, the TMPRSS6-associated disorder is polycythemia vera. Polycythemia vera is a type of blood cancer which causes the bone marrow to make excess red blood cells. These excess cells usually thinken the blood vessels, which make the patients more prone to develop blood clots, and other complications such as stroke or heart attack. Several tests may be performed to help detect and diagnose polycythemia vera, for example, a complete blood count, blood smear test, erythropoietin level test, bone marrow aspiration or biopsy, or gene sequencing.

“Therapeutically effective amount,” as used herein, is intended to include the amount of an RNAi agent that, when administered to a subject having a TMPRSS6-associated disease, is sufficient to effect treatment of the disease (e.g., by diminishing, ameliorating, or maintaining the existing disease or one or more symptoms of disease). The “therapeutically effective amount” may vary depending on the RNAi agent, how the agent is administered, the disease and its severity and the history, age, weight, family history, genetic makeup, the types of preceding or concomitant treatments, if any, and other individual characteristics of the subject to be treated.

“Prophylactically effective amount,” as used herein, is intended to include the amount of an RNAi agent that, when administered to a subject having a TMPRSS6-associated disorder, is sufficient to prevent or ameliorate the disease or one or more symptoms of the disease. Ameliorating the disease includes slowing the course of the disease or reducing the severity of later-developing disease. The “prophylactically effective amount” may vary depending on the RNAi agent, how the agent is administered, the degree of risk of disease, and the history, age, weight, family history, genetic makeup, the types of preceding or concomitant treatments, if any, and other individual characteristics of the patient to be treated.

A “therapeutically-effective amount” or “prophylactically effective amount” also includes an amount of an RNAi agent that produces some desired effect at a reasonable benefit/risk ratio applicable to any treatment. The iRNA employed in the methods of the present invention may be administered in a sufficient amount to produce a reasonable benefit/risk ratio applicable to such treatment.

The phrase “pharmaceutically acceptable” is employed herein to refer to those compounds, materials (including salts), compositions, or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human subjects and animal subjects without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.

The phrase “pharmaceutically-acceptable carrier” as used herein means a pharmaceutically-acceptable material, composition, or vehicle, such as a liquid or solid filler, diluent, excipient, manufacturing aid (e.g., lubricant, talc magnesium, calcium or zinc stearate, or steric acid), or solvent encapsulating material, involved in carrying or transporting the subject compound from one organ, or portion of the body, to another organ, or portion of the body. Each carrier must be “acceptable” in the sense of being compatible with the other ingredients of the formulation and not injurious to the subject being treated. Such carriers are known in the art. Pharmaceutically acceptable carriers include carriers for administration by injection.

The term “sample,” as used herein, includes a collection of similar fluids, cells, or tissues isolated from a subject, as well as fluids, cells, or tissues present within a subject. Examples of biological fluids include blood, serum and serosal fluids, plasma, cerebrospinal fluid, ocular fluids, lymph, urine, saliva, and the like. Tissue samples may include samples from tissues, organs, or localized regions. For example, samples may be derived from particular organs, parts of organs, or fluids or cells within those organs. In certain embodiments, samples may be derived from the liver (e.g., whole liver or certain segments of liver or certain types of cells in the liver, such as, e.g., hepatocytes). In some embodiments, a “sample derived from a subject” refers to urine obtained from the subject. A “sample derived from a subject” can refer to blood or blood derived serum or plasma from the subject.

II. iRNAs of the Invention

The present invention provides iRNAs which inhibit the expression of a TMPRSS6 gene. In certain embodiments, the iRNA includes double stranded ribonucleic acid (dsRNA) molecules for inhibiting the expression of a TMPRSS6 gene in a cell, such as a cell within a subject, e.g., a mammal, such as a human susceptible to developing a TMPRSS6-associated disorder, e.g., a disorder associated with iron overload and/or a disorder of ineffective erythropoiesis, e.g., hereditary hemochromatosis, β-thalassemia (e.g., β-thalassemia major and β-thalassemia intermedia), polycythemia vera, myelodysplastic syndrome, congenital dyserythropoietic anemias, pyruvate kinase deficiency, erythropoietic porphyria, Parkinson's Disease, Alzheimer's Disease or Friedreich's Ataxia. The dsRNAi agent includes an antisense strand having a region of complementarity which is complementary to at least a part of an mRNA formed in the expression of a TMPRSS6 gene. The region of complementarity is about 19-30 nucleotides in length (e.g., about 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, or 19 nucleotides in length).

Upon contact with a cell expressing the TMPRSS6 gene, the iRNA inhibits the expression of the TMPRSS6 gene (e.g., a human, a primate, a non-primate, or a rat TMPRSS6 gene) by at least about 50% as assayed by, for example, a PCR or branched DNA (bDNA)-based method, or by a protein-based method, such as by immunofluorescence analysis, using, for example, western blotting or flow cytometric techniques. In certain embodiments, inhibition of expression is determined by the qPCR method provided in the examples herein with the siRNA at, e.g., a 10 nM concentration, in an appropriate organism cell line provided therein. In certain embodiments, inhibition of expression in vivo is determined by knockdown of the human gene in a rodent expressing the human gene, e.g., a mouse or an AAV-infected mouse expressing the human target gene, e.g., when administered as single dose, e.g., at 3 mg/kg at the nadir of RNA expression.

A dsRNA includes two RNA strands that are complementary and hybridize to form a duplex structure under conditions in which the dsRNA will be used. One strand of a dsRNA (the antisense strand) includes a region of complementarity that is substantially complementary, and generally fully complementary, to a target sequence. The target sequence can be derived from the sequence of an mRNA formed during the expression of a TMPRSS6 gene. The other strand (the sense strand) includes a region that is complementary to the antisense strand, such that the two strands hybridize and form a duplex structure when combined under suitable conditions. As described elsewhere herein and as known in the art, the complementary sequences of a dsRNA can also be contained as self-complementary regions of a single nucleic acid molecule, as opposed to being on separate oligonucleotides.

Generally, the duplex structure is 15 to 30 base pairs in length, e.g., 15-29, 15-28, 15-27, 15-26, 15-25, 15-24, 15-23, 15-22, 15-21, 15-20, 15-19, 15-18, 15-17, 18-30, 18-29, 18-28, 18-27, 18-26, 18-25, 18-24, 18-23, 18-22, 18-21, 18-20, 19-30, 19-29, 19-28, 19-27, 19-26, 19-25, 19-24, 19-23, 19-22, 19-21, 19-20, 20-30, 20-29, 20-28, 20-27, 20-26, 20-25, 20-24, 20-23, 20-22, 20-21, 21-30, 21-29, 21-28, 21-27, 21-26, 21-25, 21-24, 21-23, or 21-22 base pairs in length. In certain embodiments, the duplex structure is 18 to 25 base pairs in length, e.g., 18-25, 18-24, 18-23, 18-22, 18-21, 18-20, 19-25, 19-24, 19-23, 19-22, 19-21, 19-20, 20-25, 20-24, 20-23, 20-22, 20-21, 21-25, 21-24, 21-23, 21-22, 22-25, 22-24, 22-23, 23-25, 23-24 or 24-25 base pairs in length, for example, 19-21 basepairs in length. Ranges and lengths intermediate to the above recited ranges and lengths are also contemplated to be part of the disclosure.

Similarly, the region of complementarity to the target sequence is 15 to 30 nucleotides in length, e.g., 15-29, 15-28, 15-27, 15-26, 15-25, 15-24, 15-23, 15-22, 15-21, 15-20, 15-19, 15-18, 15-17, 18-30, 18-29, 18-28, 18-27, 18-26, 18-25, 18-24, 18-23, 18-22, 18-21, 18-20, 19-30, 19-29, 19-28, 19-27, 19-26, 19-25, 19-24, 19-23, 19-22, 19-21, 19-20, 20-30, 20-29, 20-28, 20-27, 20-26, 20-25, 20-24,20-23, 20-22, 20-21, 21-30, 21-29, 21-28, 21-27, 21-26, 21-25, 21-24, 21-23, or 21-22 nucleotides in length, for example 19-23 nucleotides in length or 21-23 nucleotides in length. Ranges and lengths intermediate to the above recited ranges and lengths are also contemplated to be part of the disclosure.

In some embodiments, the duplex structure is 19 to 30 base pairs in length. Similarly, the region of complementarity to the target sequence is 19 to 30 nucleotides in length.

In some embodiments, the dsRNA is about 19 to about 23 nucleotides in length, or about 25 to about 30 nucleotides in length. In general, the dsRNA is long enough to serve as a substrate for the Dicer enzyme. For example, it is well-known in the art that dsRNAs longer than about 21-23 nucleotides in length may serve as substrates for Dicer. As the ordinarily skilled person will also recognize, the region of an RNA targeted for cleavage will most often be part of a larger RNA molecule, often an mRNA molecule. Where relevant, a “part” of an mRNA target is a contiguous sequence of an mRNA target of sufficient length to allow it to be a substrate for RNAi-directed cleavage (i.e., cleavage through a RISC pathway).

One of skill in the art will also recognize that the duplex region is a primary functional portion of a dsRNA, e.g., a duplex region of about 19 to about 30 base pairs, e.g., about 19-30, 19-29, 19-28, 19-27, 19-26, 19-25, 19-24, 19-23, 19-22, 19-21, 19-20, 20-30, 20-29, 20-28, 20-27, 20-26, 20-25, 20-24, 20-23, 20-22, 20-21, 21-30, 21-29, 21-28, 21-27, 21-26, 21-25, 21-24, 21-23, or 21-22 base pairs. Thus, in one embodiment, to the extent that it becomes processed to a functional duplex, of e.g., 15-30 base pairs, that targets a desired RNA for cleavage, an RNA molecule or complex of RNA molecules having a duplex region greater than 30 base pairs is a dsRNA. Thus, an ordinarily skilled artisan will recognize that in one embodiment, a miRNA is a dsRNA. In another embodiment, a dsRNA is not a naturally occurring miRNA. In another embodiment, an iRNA agent useful to target TMPRSS6 gene expression is not generated in the target cell by cleavage of a larger dsRNA.

A dsRNA as described herein can further include one or more single-stranded nucleotide overhangs, e.g., 1-4, 2-4, 1-3, 2-3, 1, 2, 3, or 4 nucleotides. dsRNAs having at least one nucleotide overhang can have superior inhibitory properties relative to their blunt-ended counterparts. A nucleotide overhang can comprise or consist of a nucleotide/nucleoside analog, including a deoxynucleotide/nucleoside. The overhang(s) can be on the sense strand, the antisense strand, or any combination thereof. Furthermore, the nucleotide(s) of an overhang can be present on the 5′-end, 3′-end, or both ends of an antisense or sense strand of a dsRNA.

A dsRNA can be synthesized by standard methods known in the art. Double stranded RNAi compounds of the invention may be prepared using a two-step procedure. First, the individual strands of the double stranded RNA molecule are prepared separately. Then, the component strands are annealed. The individual strands of the siRNA compound can be prepared using solution-phase or solid-phase organic synthesis or both. Organic synthesis offers the advantage that the oligonucleotide strands comprising unnatural or modified nucleotides can be easily prepared. Similarly, single-stranded oligonucleotides of the invention can be prepared using solution-phase or solid-phase organic synthesis or both.

In an aspect, a dsRNA of the invention includes at least two nucleotide sequences, a sense sequence and an anti-sense sequence. The sense strand is selected from the group of sequences provided in any one of Tables 2-7, and the corresponding antisense strand of the sense strand is selected from the group of sequences of any one of Tables 2-7. In this aspect, one of the two sequences is complementary to the other of the two sequences, with one of the sequences being substantially complementary to a sequence of an mRNA generated in the expression of a TMPRSS6 gene. As such, in this aspect, a dsRNA will include two oligonucleotides, where one oligonucleotide is described as the sense strand in any one of Tables 2-7, and the second oligonucleotide is described as the corresponding antisense strand of the sense strand in any one of Tables 2-7.

In certain embodiments, the substantially complementary sequences of the dsRNA are contained on separate oligonucleotides. In other embodiments, the substantially complementary sequences of the dsRNA are contained on a single oligonucleotide.

In one embodiment, the antisense strand comprises at least 15, e.g., 15, 16, 17, 18, 19, or 20, contiguous nucleotides differing by no more than 0, 1, 2, or 3 nucleotides from any one of the antisense strand nucleotide sequences in any one of Tables 2-7.

It will be understood that, although the sequences in, for example, Tables 3 or 5, are not described as modified or conjugated sequences, the RNA of the iRNA of the invention e.g., a dsRNA of the invention, may comprise any one of the sequences set forth in any one of Tables 2-7 that is un-modified, un-conjugated, or modified or conjugated differently than described therein. In other words, the invention encompasses dsRNA of Tables 2-7 which are un-modified, un-conjugated, modified, or conjugated, as described herein.

The skilled person is well aware that dsRNAs having a duplex structure of about 20 to 23 base pairs, e.g., 21, base pairs have been hailed as particularly effective in inducing RNA interference (Elbashir et al., EMBO 2001, 20:6877-6888). However, others have found that shorter or longer RNA duplex structures can also be effective (Chu and Rana (2007) RNA 14:1714-1719; Kim et al. (2005) Nat Biotech 23:222-226). In the embodiments described above, by virtue of the nature of the oligonucleotide sequences provided in any one of Tables 2-7. dsRNAs described herein can include at least one strand of a length of minimally 21 nucleotides. It can be reasonably expected that shorter duplexes having any one of the sequences in any one of Tables 2-7 minus only a few nucleotides on one or both ends can be similarly effective as compared to the dsRNAs described above. Hence, dsRNAs having a sequence of at least 19, 20, or more contiguous nucleotides derived from any one of the sequences of any one of Tables 2-7, and differing in their ability to inhibit the expression of a TMPRSS6 gene by not more than about 5, 10, 15, 20, 25, or 30% inhibition from a dsRNA comprising the full sequence, are contemplated to be within the scope of the present invention.

In addition, the RNAs provided in Tables 2-7 identify a site(s) in a TMPRSS6 transcript that is susceptible to RISC-mediated cleavage. As such, the present invention further features iRNAs that target within one of these sites. As used herein, an iRNA is said to target within a particular site of an RNA transcript if the iRNA promotes cleavage of the transcript anywhere within that particular site. Such an iRNA will generally include at least about 19 contiguous nucleotides from any one of the sequences provided in any one of Tables 2-7 coupled to additional nucleotide sequences taken from the region contiguous to the selected sequence in a TMPRSS6 gene.

III. Modified iRNAs of the Invention

In certain embodiments, the RNA of the iRNA of the invention e.g., a dsRNA, is un-modified, and does not comprise, e.g., chemical modifications or conjugations known in the art and described herein. In other embodiments, the RNA of an iRNA of the invention, e.g., a dsRNA, is chemically modified to enhance stability or other beneficial characteristics. In certain embodiments of the invention, substantially all of the nucleotides of an iRNA of the invention are modified. In other embodiments of the invention, all of the nucleotides of an iRNA or substantially all of the nucleotides of an iRNA are modified, i.e., not more than 5, 4, 3, 2, or lunmodified nucleotides are present in a strand of the iRNA.

The nucleic acids featured in the invention can be synthesized or modified by methods well established in the art, such as those described in “Current protocols in nucleic acid chemistry,” Beaucage, S. L. et al. (Edrs.), John Wiley & Sons, Inc., New York, NY, USA, which is hereby incorporated herein by reference. Modifications include, for example, end modifications, e.g., 5′-end modifications (phosphorylation, conjugation, inverted linkages) or 3′-end modifications (conjugation, DNA nucleotides, inverted linkages, etc.); base modifications, e.g., replacement with stabilizing bases, destabilizing bases, or bases that base pair with an expanded repertoire of partners, removal of bases (abasic nucleotides), or conjugated bases; sugar modifications (e.g., at the 2′-position or 4′-position) or replacement of the sugar; or backbone modifications, including modification or replacement of the phosphodiester linkages. Specific examples of iRNA compounds useful in the embodiments described herein include, but are not limited to RNAs containing modified backbones or no natural internucleoside linkages. RNAs having modified backbones include, among others, those that do not have a phosphorus atom in the backbone. For the purposes of this specification, and as sometimes referenced in the art, modified RNAs that do not have a phosphorus atom in their internucleoside backbone can also be considered to be oligonucleosides. In some embodiments, a modified iRNA will have a phosphorus atom in its internucleoside backbone.

Modified RNA backbones include, for example, phosphorothioates, chiral phosphorothioates, phosphorodithioates, phosphotriesters, aminoalkylphosphotriesters, methyl and other alkyl phosphonates including 3′-alkylene phosphonates and chiral phosphonates, phosphinates, phosphoramidates including 3′-amino phosphoramidate and aminoalkylphosphoramidates, thionophosphoramidates, thionoalkylphosphonates, thionoalkylphosphotriesters, and boranophosphates having normal 3′-5′ linkages, 2′-5′-linked analogs of these, and those having inverted polarity wherein the adjacent pairs of nucleoside units are linked 3′-5′ to 5′-3′ or 2′-5′ to 5′-2′. Various salts, mixed salts and free acid forms are also included. In some embodiments of the invention, the dsRNA agents of the invention are in a free acid form. In other embodiments of the invention, the dsRNA agents of the invention are in a salt form. In one embodiment, the dsRNA agents of the invention are in a sodium salt form. In certain embodiments, when the dsRNA agents of the invention are in the sodium salt form, sodium ions are present in the agent as counterions for substantially all of the phosphodiester and/or phosphorothiotate groups present in the agent. Agents in which substantially all of the phosphodiester and/or phosphorothioate linkages have a sodium counterion include not more than 5, 4, 3, 2, or 1 phosphodiester and/or phosphorothioate linkages without a sodium counterion. In some embodiments, when the dsRNA agents of the invention are in the sodium salt form, sodium ions are present in the agent as counterions for all of the phosphodiester and/or phosphorothiotate groups present in the agent.

Representative U.S. Patents that teach the preparation of the above phosphorus-containing linkages include, but are not limited to, U.S. Pat. Nos. 3,687,808; 4,469,863; 4,476,301; 5,023,243; 5,177,195; 5,188,897; 5,264,423; 5,276,019; 5,278,302; 5,286,717; 5,321,131; 5,399,676; 5,405,939; 5,453,496; 5,455,233; 5,466,677; 5,476,925; 5,519,126; 5,536,821; 5,541,316; 5,550,111; 5,563,253; 5,571,799; 5,587,361; 5,625,050; 6,028,188; 6,124,445; 6,160,109; 6,169,170; 6,172,209; 6,239,265; 6,277,603; 6,326,199; 6,346,614; 6,444,423; 6,531,590; 6,534,639; 6,608,035; 6,683,167; 6,858,715; 6,867,294; 6,878,805; 7,015,315; 7,041,816; 7,273,933; 7,321,029; and U.S. Pat RE39464, the entire contents of each of which are hereby incorporated herein by reference.

Modified RNA backbones that do not include a phosphorus atom therein have backbones that are formed by short chain alkyl or cycloalkyl internucleoside linkages, mixed heteroatoms and alkyl or cycloalkyl internucleoside linkages, or one or more short chain heteroatomic or heterocyclic internucleoside linkages. These include those having morpholino linkages (formed in part from the sugar portion of a nucleoside); siloxane backbones; sulfide, sulfoxide and sulfone backbones; formacetyl and thioformacetyl backbones; methylene formacetyl and thioformacetyl backbones; alkene containing backbones; sulfamate backbones; methyleneimino and methylenehydrazino backbones; sulfonate and sulfonamide backbones; amide backbones; and others having mixed N, O, S, and CH₂component parts.

Representative U.S. Patents that teach the preparation of the above oligonucleosides include, but are not limited to, U.S. Pat. Nos. 5,034,506; 5,166,315; 5,185,444; 5,214,134; 5,216,141; 5,235,033; 5,64,562; 5,264,564; 5,405,938; 5,434,257; 5,466,677; 5,470,967; 5,489,677; 5,541,307; 5,561,225; 5,596,086; 5,602,240; 5,608,046; 5,610,289; 5,618,704; 5,623,070; 5,663,312; 5,633,360; 5,677,437; and 5,677,439, the entire contents of each of which are hereby incorporated herein by reference.

Suitable RNA mimetics are contemplated for use in iRNAs provided herein, in which both the sugar and the internucleoside linkage, i.e., the backbone, of the nucleotide units are replaced with novel groups. The base units are maintained for hybridization with an appropriate nucleic acid target compound. One such oligomeric compound in which an RNA mimetic that has been shown to have excellent hybridization properties is referred to as a peptide nucleic acid (PNA). In PNA compounds, the sugar backbone of an RNA is replaced with an amide containing backbone, in particular an aminoethylglycine backbone. The nucleobases are retained and are bound directly or indirectly to aza nitrogen atoms of the amide portion of the backbone. Representative US patents that teach the preparation of PNA compounds include, but are not limited to, U.S. Pat. Nos. 5,539,082; 5,714,331; and 5,719,262, the entire contents of each of which are hereby incorporated herein by reference. Additional PNA compounds suitable for use in the iRNAs of the invention are described in, for example, in Nielsen et al., Science, 1991, 254, 1497-1500.

Some embodiments featured in the invention include RNAs with phosphorothioate backbones and oligonucleosides with heteroatom backbones, and in particular —CH₂—NH—CH₂—, —CH₂—N(CH₃)—O—CH₂-[known as a methylene (methylimino) or MMI backbone], —CH₂—O—N(CH₃)—CH₂—, —CH₂—N(CH₃)—N(CH₃)—CH₂— and —N(CH₃)—CH₂—CH₂— of the above-referenced U.S. Pat. No. 5,489,677, and the amide backbones of the above-referenced U.S. Pat. No. 5,602,240. In some embodiments, the RNAs featured herein have morpholino backbone structures of the above-referenced U.S. Pat. No. 5,034,506. The native phosphodiester backbone can be represented as O—P(O)(OH)—OCH₂—.

Modified RNAs can also contain one or more substituted sugar moieties. The iRNAs, e.g., dsRNAs, featured herein can include one of the following at the 2′-position: OH; F; O-, S-, or N-alkyl; O-, S-, or N-alkenyl; O-, S- or N-alkynyl; or O-alkyl-O-alkyl, wherein the alkyl, alkenyl and alkynyl can be substituted or unsubstituted C₁to C₁₀alkyl or C₂to C₁₀alkenyl and alkynyl. Exemplary suitable modifications include O[(CH₂)_nO]_mCH₃, O(CH₂)_·nOCH₃, O(CH₂)_nNH₂, O(CH₂)_nCH₃, O(CH₂)_nONH₂, and O(CH₂)_nON[(CH₂)_nCH₃)]₂, where n and m are from 1 to about 10. In other embodiments, dsRNAs include one of the following at the 2′ position: C₁to C₁₀lower alkyl, substituted lower alkyl, alkaryl, aralkyl, O-alkaryl or O-aralkyl, SH, SCH₃, OCN, Cl, Br, CN, CF₃, OCF₃, SOCH₃, SO₂CH₃, ONO₂, NO₂, N₃, NH₂, heterocycloalkyl, heterocycloalkaryl, aminoalkylamino, polyalkylamino, substituted silyl, an RNA cleaving group, a reporter group, an intercalator, a group for improving the pharmacokinetic properties of an iRNA, or a group for improving the pharmacodynamic properties of an iRNA, and other substituents having similar properties. In some embodiments, the modification includes a 2′-methoxyethoxy (2′-O—CH₂CH₂OCH₃, also known as 2′-O-(2-methoxyethyl) or 2′-MOE) (Martin et al., Helv. Chim. Acta, 1995, 78:486-504) i.e., an alkoxy-alkoxy group. Another exemplary modification is 2′-dimethylaminooxyethoxy, i.e., a O(CH₂)₂ON(CH₃)₂group, also known as 2′-DMAOE, as described in examples herein below, and 2′-dimethylaminoethoxyethoxy (also known in the art as 2′-O-dimethylaminoethoxyethyl or 2′-DMAEOE), i.e., 2′-O—CH₂—O—CH₂—N(CH₃)₂. Further exemplary modifications include: 5′-Me-2′-F nucleotides, 5′-Me-2′-OMe nucleotides, 5′-Me-2′-deoxynucleotides, (both R and S isomers in these three families); 2′-alkoxyalkyl; and 2′-NMA (N-methylacetamide).

Other modifications include 2′-methoxy (2′-OCH₃), 2′-aminopropoxy (2′-OCH₂CH₂CH₂NH₂) and 2′-fluoro (2′-F). Similar modifications can also be made at other positions on the RNA of an iRNA, particularly the 3′ position of the sugar on the 3′ terminal nucleotide or in 2′-5′ linked dsRNAs and the 5′ position of 5′ terminal nucleotide. iRNAs can also have sugar mimetics such as cyclobutyl moieties in place of the pentofuranosyl sugar. Representative US patents that teach the preparation of such modified sugar structures include, but are not limited to, U.S. Pat. Nos. 4,981,957; 5,118,800; 5,319,080; 5,359,044; 5,393,878; 5,446,137; 5,466,786; 5,514,785; 5,519,134; 5,567,811; 5,576,427; 5,591,722; 5,597,909; 5,610,300; 5,627,053; 5,639,873; 5,646,265; 5,658,873; 5,670,633; and 5,700,920, certain of which are commonly owned with the instant application. The entire contents of each of the foregoing are hereby incorporated herein by reference.

An iRNA can also include nucleobase (often referred to in the art simply as “base”) modifications or substitutions. As used herein, “unmodified” or “natural” nucleobases include the purine bases adenine (A) and guanine (G), and the pyrimidine bases thymine (T), cytosine (C), and uracil (U). Modified nucleobases include other synthetic and natural nucleobases such as deoxythimidine (dT), 5-methylcytosine (5-me-C), 5-hydroxymethyl cytosine, xanthine, hypoxanthine, 2-aminoadenine, 6-methyl and other alkyl derivatives of adenine and guanine, 2-propyl and other alkyl derivatives of adenine and guanine, 2-thiouracil, 2-thiothymine and 2-thiocytosine, 5-halouracil and cytosine, 5-propynyl uracil and cytosine, 6-azo uracil, cytosine and thymine, 5-uracil (pseudouracil), 4-thiouracil, 8-halo, 8-amino, 8-thiol, 8-thioalkyl, 8-hydroxyl anal other 8-substituted adenines and guanines, 5-halo, particularly 5-bromo, 5-trifluoromethyl and other 5-substituted uracils and cytosines, 7-methylguanine and 7-methyladenine, 8-azaguanine and 8-azaadenine, 7-deazaguanine and 7-daazaadenine and 3-deazaguanine and 3-deazaadenine. Further nucleobases include those disclosed in U.S. Pat. No. 3,687,808, those disclosed in Modified Nucleosides in Biochemistry, Biotechnology and Medicine, Herdewijn, P. ed. Wiley-VCH, 2008; those disclosed in The Concise Encyclopedia Of Polymer Science And Engineering, pages 858-859, Kroschwitz, J. L, ed. John Wiley & Sons, 1990, these disclosed by Englisch et al., Angewandte Chemie, International Edition, 1991, 30, 613, and those disclosed by Sanghvi, Y S., Chapter 15, dsRNA Research and Applications, pages 289-302, Crooke, S. T. and Lebleu, B., Ed., CRC Press, 1993. Certain of these nucleobases are particularly useful for increasing the binding affinity of the oligomeric compounds featured in the invention. These include 5-substituted pyrimidines, 6-azapyrimidines and N-2, N-6 and 0-6 substituted purines, including 2-aminopropyladenine, 5-propynyluracil and 5-propynylcytosine. 5-methylcytosine substitutions have been shown to increase nucleic acid duplex stability by 0.6-1.2° C. (Sanghvi, Y. S., Crooke, S. T. and Lebleu, B., Eds., dsRNA Research and Applications, CRC Press, Boca Raton, 1993, pp. 276-278) and are exemplary base substitutions, even more particularly when combined with 2′-O-methoxyethyl sugar modifications.

Representative U.S. Patents that teach the preparation of certain of the above noted modified nucleobases as well as other modified nucleobases include, but are not limited to, the above noted U.S. Pat. Nos. 3,687,808, 4,845,205; 5,130,30; 5,134,066; 5,175,273; 5,367,066; 5,432,272; 5,457,187; 5,459,255; 5,484,908; 5,502,177; 5,525,711; 5,552,540; 5,587,469; 5,594,121, 5,596,091; 5,614,617; 5,681,941; 5,750,692; 6,015,886; 6,147,200; 6,166,197; 6,222,025; 6,235,887; 6,380,368; 6,528,640; 6,639,062; 6,617,438; 7,045,610; 7,427,672; and 7,495,088, the entire contents of each of which are hereby incorporated herein by reference.

In some embodiments, an RNAi agent of the disclosure can also be modified to include one or more bicyclic sugar moieties. A “bicyclic sugar” is a furanosyl ring modified by a ring formed by the bridging of two carbons, whether adjacent or non-adjacent. A “bicyclic nucleoside” (“BNA”) is a nucleoside having a sugar moiety comprising a ring formed by bridging two carbons, whether adjacent or non-adjacent, of the sugar ring, thereby forming a bicyclic ring system. In certain embodiments, the bridge connects the 4′-carbon and the 2′-carbon of the sugar ring, optionally, via the 2′-acyclic oxygen atom. Thus, in some embodiments an agent of the invention may include one or more locked nucleic acids (LNA). A locked nucleic acid is a nucleotide having a modified ribose moiety in which the ribose moiety comprises an extra bridge connecting the 2′ and 4′ carbons. In other words, an LNA is a nucleotide comprising a bicyclic sugar moiety comprising a 4′-CH₂—O-2′ bridge. This structure effectively “locks” the ribose in the 3′-endo structural conformation. The addition of locked nucleic acids to siRNAs has been shown to increase siRNA stability in serum, and to reduce off-target effects (Elmen, J. et al., (2005) Nucleic Acids Research 33(1):439-447; Mook, O R. et al., (2007) Mol Canc Ther 6(3):833-843; Grunweller, A. et al., (2003) Nucleic Acids Research 31(12):3185-3193). Examples of bicyclic nucleosides for use in the polynucleotides of the invention include without limitation nucleosides comprising a bridge between the 4′ and the 2′ ribosyl ring atoms. In certain embodiments, the antisense polynucleotide agents of the invention include one or more bicyclic nucleosides comprising a 4′ to 2′ bridge.

A locked nucleoside can be represented by the structure (omitting stereochemistry),

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wherein B is a nucleobase or modified nucleobase and L is the linking group that joins the 2′-carbon to the 4′-carbon of the ribose ring. Examples of such 4′ to 2′ bridged bicyclic nucleosides, include but are not limited to 4′-(CH₂)—O-2′ (LNA); 4′-(CH₂)—S-2′; 4′-(CH₂)₂—O-2′ (ENA); 4′-CH(CH₃)—O-2′ (also referred to as “constrained ethyl” or “cEt”) and 4′-CH(CH₂OCH₃)—O-2′ (and analogs thereof; see, e.g., U.S. Pat. No. 7,399,845); 4′-C(CH₃)(CH₃)—O-2′ (and analogs thereof; see e.g., U.S. Pat. No. 8,278,283); 4′-CH₂—N(OCH₃)-2′ (and analogs thereof; see e.g., U.S. Pat. No. 8,278,425); 4′-CH₂—O—N(CH₃)-2′ (see, e.g., U.S. Patent Publication No. 2004/0171570); 4′-CH₂—N(R)—O—2′, wherein R is H, C1-C12 alkyl, or a nitrogen protecting group (see, e.g., U.S. Pat. No. 7,427,672); 4′-CH₂—C(H)(CH₃)-2′ (see, e.g., Chattopadhyaya et al., J. Org. Chem., 2009, 74, 118-134); and 4′-CH₂—C(═CH₂)-2′ (and analogs thereof; see, e.g., U.S. Pat. No. 8,278,426). The entire contents of each of the foregoing are hereby incorporated herein by reference.

Additional representative U.S. Patents and U.S. Patent Publications that teach the preparation of locked nucleic acid nucleotides include, but are not limited to, the following: U.S. Pat. Nos. 6,268,490; 6,525,191; 6,670,461; 6,770,748; 6,794,499; 6,998,484; 7,053,207; 7,034,133; 7,084,125; 7,399,845; 7,427,672; 7,569,686; 7,741,457; 8,022,193; 8,030,467; 8,278,425; 8,278,426; 8,278,283; US 2008/0039618; and US 2009/0012281, the entire contents of each of which are hereby incorporated herein by reference.

Any of the foregoing bicyclic nucleosides can be prepared having one or more stereochemical sugar configurations including for example α-L-ribofuranose and β-D-ribofuranose (see WO 99/14226).

The RNA of an iRNA can also be modified to include one or more constrained ethyl nucleotides. As used herein, a “constrained ethyl nucleotide” or “cEt” is a locked nucleic acid comprising a bicyclic sugar moiety comprising a 4′-CH(CH₃)—O-2′ bridge (i.e., L in the preceding structure). In one embodiment, a constrained ethyl nucleotide is in the S conformation referred to herein as “S-cEt.”

An iRNA of the invention may also include one or more “conformationally restricted nucleotides” (“CRN”). CRN are nucleotide analogs with a linker connecting the C2′ and C4′ carbons of ribose or the C3 and —C5′ carbons of ribose. CRN lock the ribose ring into a stable conformation and increase the hybridization affinity to mRNA. The linker is of sufficient length to place the oxygen in an optimal position for stability and affinity resulting in less ribose ring puckering.

Representative publications that teach the preparation of certain of the above noted CRN include, but are not limited to, U.S. Patent Publication No. 2013/0190383; and PCT publication WO 2013/036868, the entire contents of each of which are hereby incorporated herein by reference.

In some embodiments, an iRNA of the invention comprises one or more monomers that are UNA (unlocked nucleic acid) nucleotides. UNA is unlocked acyclic nucleic acid, wherein any of the bonds of the sugar has been removed, forming an unlocked “sugar” residue. In one example, UNA also encompasses monomer with bonds between C1′-C4′ have been removed (i.e. the covalent carbon-oxygen-carbon bond between the C1′ and C4′ carbons). In another example, the C2′-C3′ bond (i.e. the covalent carbon-carbon bond between the C2′ and C3′ carbons) of the sugar has been removed (see Nuc. Acids Symp. Series, 52, 133-134 (2008) and Fluiter et al., Mol. Biosyst., 2009, 10, 1039 hereby incorporated by reference).

Representative U.S. publications that teach the preparation of UNA include, but are not limited to, U.S. Pat. No. 8,314,227; and U.S. Patent Publication Nos. 2013/0096289; 2013/0011922; and 2011/0313020, the entire contents of each of which are hereby incorporated herein by reference.

Potentially stabilizing modifications to the ends of RNA molecules can include N-(acetylaminocaproyl)-4-hydroxyprolinol (Hyp-C6-NHAc), N-(caproyl-4-hydroxyprolinol (Hyp-C6), N-(acetyl-4-hydroxyprolinol (Hyp-NHAc), thymidine-2′-O-deoxythymidine (ether), N-(aminocaproyl)-4-hydroxyprolinol (Hyp-C6-amino), 2-docosanoyl-uridine-3′-phosphate, inverted 2′-deoxy-modified ribonucleotide, such as inverted dT(idT), inverted dA (idA), and inverted abasic 2′-deoxyribonucleotide (iAb) and others. Disclosure of this modification can be found in WO 2011/005861.

In one example, the 3′ or 5′ terminal end of a oligonucleotide is linked to an inverted 2′-deoxy-modified ribonucleotide, such as inverted dT(idT), inverted dA (idA), or a inverted abasic 2′-deoxyribonucleotide (iAb). In one particular example, the inverted 2′-deoxy-modified ribonucleotide is linked to the 3′end of an oligonucleotide, such as the 3′-end of a sense strand described herein, where the linking is via a 3′-3′ phosphodiester linkage or a 3′-3′-phosphorothioate linkage.

In another example, the 3′-end of a sense strand is linked via a 3′-3′-phosphorothioate linkage to an inverted abasic ribonucleotide (iAb). In another example, the 3′-end of a sense strand is linked via a 3′-3′-phosphorothioate linkage to an inverted dA (idA).

In one particular example, the inverted 2′-deoxy-modified ribonucleotide is linked to the 3′end of an oligonucleotide, such as the 3′-end of a sense strand described herein, where the linking is via a 3′-3′ phosphodiester linkage or a 3′-3′-phosphorothioate linkage.

In another example, the 3′-terminal nucleotides of a sense strand is an inverted dA (idA) and is linked to the preceding nucleotide via a 3′-3′-linkage (e.g., 3′-3′-phosphorothioate linkage).

Other modifications of the nucleotides of an iRNA of the invention include a 5′ phosphate or 5′ phosphate mimic, e.g., a 5′-terminal phosphate or phosphate mimic on the antisense strand of an iRNA. Suitable phosphate mimics are disclosed in, for example U.S. Patent Publication No. 2012/0157511, the entire contents of which are incorporated herein by reference.

A. Modified iRNAs Comprising Motifs of the Invention

In certain aspects of the invention, the double stranded RNA agents of the invention include agents with chemical modifications as disclosed, for example, in WO2013/075035, the entire contents of each of which are incorporated herein by reference. As shown herein and in WO2013/075035, one or more motifs of three identical modifications on three consecutive nucleotides may be introduced into a sense strand or antisense strand of a dsRNAi agent, particularly at or near the cleavage site. In some embodiments, the sense strand and antisense strand of the dsRNAi agent may otherwise be completely modified. The introduction of these motifs interrupts the modification pattern, if present, of the sense or antisense strand. The dsRNAi agent may be optionally conjugated with a GalNAc derivative ligand, for instance on the sense strand.

More specifically, when the sense strand and antisense strand of the double stranded RNA agent are completely modified to have one or more motifs of three identical modifications on three consecutive nucleotides at or near the cleavage site of at least one strand of a dsRNAi agent, the gene silencing activity of the dsRNAi agent was observed.

Accordingly, the invention provides double stranded RNA agents capable of inhibiting the expression of a target gene (i.e., TMPRSS6 gene) in vivo. The RNAi agent comprises a sense strand and an antisense strand. Each strand of the RNAi agent may be, for example, 17-30 nucleotides in length, 25-30 nucleotides in length, 27-30 nucleotides in length, 19-25 nucleotides in length, 19-23 nucleotides in length, 19-21 nucleotides in length, 21-25 nucleotides in length, or 21-23 nucleotides in length.

The sense strand and antisense strand typically form a duplex double stranded RNA (“dsRNA”), also referred to herein as “dsRNAi agent.” The duplex region of a dsRNAi agent may be, for example, the duplex region can be 27-30 nucleotide pairs in length, 19-25 nucleotide pairs in length, 19-23 nucleotide pairs in length, 19-21 nucleotide pairs in length, 21-25 nucleotide pairs in length, or 21-23 nucleotide pairs in length. In another example, the duplex region is selected from 19, 20, 21, 22, 23, 24, 25, 26, and 27 nucleotides in length.

In certain embodiments, the dsRNAi agent may contain one or more overhang regions or capping groups at the 3′-end, 5′-end, or both ends of one or both strands. The overhang can be, independently, 1-6 nucleotides in length, for instance 2-6 nucleotides in length, 1-5 nucleotides in length, 2-5 nucleotides in length, 1-4 nucleotides in length, 2-4 nucleotides in length, 1-3 nucleotides in length, 2-3 nucleotides in length, or 1-2 nucleotides in length. In certain embodiments, the overhang regions can include extended overhang regions as provided above. The overhangs can be the result of one strand being longer than the other, or the result of two strands of the same length being staggered. The overhang can form a mismatch with the target mRNA or it can be complementary to the gene sequences being targeted or can be another sequence. The first and second strands can also be joined, e.g., by additional bases to form a hairpin, or by other non-base linkers.

In certain embodiments, the nucleotides in the overhang region of the dsRNAi agent can each independently be a modified or unmodified nucleotide including, but no limited to 2′-sugar modified, such as, 2′-F, 2′-O-methyl, thymidine (T), 2′-O-methoxyethyl-5-methyluridine (Teo), 2′-O-methoxyethyladenosine (Aeo), 2′-O-methoxyethyl-5-methylcytidine (m5Ceo), and any combinations thereof.

For example, TT can be an overhang sequence for either end on either strand. The overhang can form a mismatch with the target mRNA or it can be complementary to the gene sequences being targeted or can be another sequence.

The 5′- or 3′-overhangs at the sense strand, antisense strand, or both strands of the dsRNAi agent may be phosphorylated. In some embodiments, the overhang region(s) contains two nucleotides having a phosphorothioate between the two nucleotides, where the two nucleotides can be the same or different. In some embodiments, the overhang is present at the 3′-end of the sense strand, antisense strand, or both strands. In some embodiments, this 3′-overhang is present in the antisense strand. In some embodiments, this 3′-overhang is present in the sense strand.

The dsRNAi agent may contain only a single overhang, which can strengthen the interference activity of the RNAi, without affecting its overall stability. For example, the single-stranded overhang may be located at the 3′-end of the sense strand or, alternatively, at the 3′-end of the antisense strand. The RNAi may also have a blunt end, located at the 5′-end of the antisense strand (i.e., the 3′-end of the sense strand) or vice versa. Generally, the antisense strand of the dsRNAi agent has a nucleotide overhang at the 3′-end, and the 5′-end is blunt. While not wishing to be bound by theory, the asymmetric blunt end at the 5′-end of the antisense strand and 3′-end overhang of the antisense strand favor the guide strand loading into RISC process.

In certain embodiments, the dsRNAi agent is a double blunt-ended of 19 nucleotides in length, wherein the sense strand contains at least one motif of three 2′-F modifications on three consecutive nucleotides at positions 7, 8, 9 from the 5′end. The antisense strand contains at least one motif of three 2′-O-methyl modifications on three consecutive nucleotides at positions 11, 12, and 13 from the 5′end.

In other embodiments, the dsRNAi agent is a double blunt-ended of 20 nucleotides in length, wherein the sense strand contains at least one motif of three 2′-F modifications on three consecutive nucleotides at positions 8, 9, and 10 from the 5′end. The antisense strand contains at least one motif of three 2′-O-methyl modifications on three consecutive nucleotides at positions 11, 12, and 13 from the 5′end.

In yet other embodiments, the dsRNAi agent is a double blunt-ended of 21 nucleotides in length, wherein the sense strand contains at least one motif of three 2′-F modifications on three consecutive nucleotides at positions 9, 10, and 11 from the 5′end. The antisense strand contains at least one motif of three 2′-0-methyl modifications on three consecutive nucleotides at positions 11, 12, and 13 from the 5′end.

In certain embodiments, the dsRNAi agent comprises a 21 nucleotide sense strand and a 23 nucleotide antisense strand, wherein the sense strand contains at least one motif of three 2′-F modifications on three consecutive nucleotides at positions 9, 10, and 11 from the 5′end; the antisense strand contains at least one motif of three 2′-0-methyl modifications on three consecutive nucleotides at positions 11, 12, and 13 from the 5′end, wherein one end of the RNAi agent is blunt, while the other end comprises a 2 nucleotide overhang. In one embodiment, the 2 nucleotide overhang is at the 3′-end of the antisense strand.

When the 2 nucleotide overhang is at the 3′-end of the antisense strand, there may be two phosphorothioate internucleotide linkages between the terminal three nucleotides, wherein two of the three nucleotides are the overhang nucleotides, and the third nucleotide is a paired nucleotide next to the overhang nucleotide. In one embodiment, the RNAi agent additionally has two phosphorothioate internucleotide linkages between the terminal three nucleotides at both the 5′-end of the sense strand and at the 5′-end of the antisense strand. In certain embodiments, every nucleotide in the sense strand and the antisense strand of the dsRNAi agent, including the nucleotides that are part of the motifs are modified nucleotides. In certain embodiments each residue is independently modified with a 2′-O-methyl or 3′-fluoro, e.g., in an alternating motif. Optionally, the dsRNAi agent further comprises a ligand (such as, GalNAc₃).

In certain embodiments, the dsRNAi agent comprises a sense and an antisense strand, wherein the sense strand is 25-30 nucleotide residues in length, wherein starting from the 5′ terminal nucleotide (position 1) positions 1 to 23 of the first strand comprise at least 8 ribonucleotides; the antisense strand is 36-66 nucleotide residues in length and, starting from the 3′ terminal nucleotide, comprises at least 8 ribonucleotides in the positions paired with positions 1-23 of sense strand to form a duplex; wherein at least the 3 ‘ terminal nucleotide of antisense strand is unpaired with sense strand, and up to 6 consecutive 3’ terminal nucleotides are unpaired with sense strand, thereby forming a 3′ single stranded overhang of 1-6 nucleotides; wherein the 5′ terminus of antisense strand comprises from 10-30 consecutive nucleotides which are unpaired with sense strand, thereby forming a 10-30 nucleotide single stranded 5′ overhang; wherein at least the sense strand 5′ terminal and 3′ terminal nucleotides are base paired with nucleotides of antisense strand when sense and antisense strands are aligned for maximum complementarity, thereby forming a substantially duplexed region between sense and antisense strands; and antisense strand is sufficiently complementary to a target RNA along at least 19 ribonucleotides of antisense strand length to reduce target gene expression when the double stranded nucleic acid is introduced into a mammalian cell; and wherein the sense strand contains at least one motif of three 2′-F modifications on three consecutive nucleotides, where at least one of the motifs occurs at or near the cleavage site. The antisense strand contains at least one motif of three 2′-O-methyl modifications on three consecutive nucleotides at or near the cleavage site.

In certain embodiments, the dsRNAi agent comprises sense and antisense strands, wherein the dsRNAi agent comprises a first strand having a length which is at least 25 and at most 29 nucleotides and a second strand having a length which is at most 30 nucleotides with at least one motif of three 2′-O-methyl modifications on three consecutive nucleotides at position 11, 12, 13 from the 5′ end; wherein the 3′ end of the first strand and the 5′ end of the second strand form a blunt end and the second strand is 1-4 nucleotides longer at its 3′ end than the first strand, wherein the duplex region which is at least 25 nucleotides in length, and the second strand is sufficiently complementary to a target mRNA along at least 19 nucleotide of the second strand length to reduce target gene expression when the RNAi agent is introduced into a mammalian cell, and wherein Dicer cleavage of the dsRNAi agent results in an siRNA comprising the 3′-end of the second strand, thereby reducing expression of the target gene in the mammal. Optionally, the dsRNAi agent further comprises a ligand.

In certain embodiments, the sense strand of the dsRNAi agent contains at least one motif of three identical modifications on three consecutive nucleotides, where one of the motifs occurs at the cleavage site in the sense strand.

In certain embodiments, the antisense strand of the dsRNAi agent can also contain at least one motif of three identical modifications on three consecutive nucleotides, where one of the motifs occurs at or near the cleavage site in the antisense strand.

For a dsRNAi agent having a duplex region of 19-23 nucleotides in length, the cleavage site of the antisense strand is typically around the 10, 11, and 12 positions from the 5′-end. Thus the motifs of three identical modifications may occur at the 9, 10, 11 positions; the 10, 11, 12 positions; the 11, 12, 13 positions; the 12, 13, 14 positions; or the 13, 14, 15 positions of the antisense strand, the count starting from the first nucleotide from the 5′-end of the antisense strand, or, the count starting from the first paired nucleotide within the duplex region from the 5′-end of the antisense strand. The cleavage site in the antisense strand may also change according to the length of the duplex region of the dsRNAi agent from the 5′-end.

The sense strand of the dsRNAi agent may contain at least one motif of three identical modifications on three consecutive nucleotides at the cleavage site of the strand; and the antisense strand may have at least one motif of three identical modifications on three consecutive nucleotides at or near the cleavage site of the strand. When the sense strand and the antisense strand form a dsRNA duplex, the sense strand and the antisense strand can be so aligned that one motif of the three nucleotides on the sense strand and one motif of the three nucleotides on the antisense strand have at least one nucleotide overlap, i.e., at least one of the three nucleotides of the motif in the sense strand forms a base pair with at least one of the three nucleotides of the motif in the antisense strand. Alternatively, at least two nucleotides may overlap, or all three nucleotides may overlap.

In some embodiments, the sense strand of the dsRNAi agent may contain more than one motif of three identical modifications on three consecutive nucleotides. The first motif may occur at or near the cleavage site of the strand and the other motifs may be a wing modification. The term “wing modification” herein refers to a motif occurring at another portion of the strand that is separated from the motif at or near the cleavage site of the same strand. The wing modification is either adjacent to the first motif or is separated by at least one or more nucleotides. When the motifs are immediately adjacent to each other then the chemistries of the motifs are distinct from each other, and when the motifs are separated by one or more nucleotide than the chemistries can be the same or different. Two or more wing modifications may be present. For instance, when two wing modifications are present, each wing modification may occur at one end relative to the first motif which is at or near cleavage site or on either side of the lead motif.

Like the sense strand, the antisense strand of the dsRNAi agent may contain more than one motif of three identical modifications on three consecutive nucleotides, with at least one of the motifs occurring at or near the cleavage site of the strand. This antisense strand may also contain one or more wing modifications in an alignment similar to the wing modifications that may be present on the sense strand.

In some embodiments, the wing modification on the sense strand or antisense strand of the dsRNAi agent typically does not include the first one or two terminal nucleotides at the 3′-end, 5′-end, or both ends of the strand.

In other embodiments, the wing modification on the sense strand or antisense strand of the dsRNAi agent typically does not include the first one or two paired nucleotides within the duplex region at the 3′-end, 5′-end, or both ends of the strand.

When the sense strand and the antisense strand of the dsRNAi agent each contain at least one wing modification, the wing modifications may fall on the same end of the duplex region, and have an overlap of one, two, or three nucleotides.

When the sense strand and the antisense strand of the dsRNAi agent each contain at least two wing modifications, the sense strand and the antisense strand can be so aligned that two modifications each from one strand fall on one end of the duplex region, having an overlap of one, two, or three nucleotides; two modifications each from one strand fall on the other end of the duplex region, having an overlap of one, two or three nucleotides; two modifications one strand fall on each side of the lead motif, having an overlap of one, two or three nucleotides in the duplex region.

In some embodiments, every nucleotide in the sense strand and antisense strand of the dsRNAi agent, including the nucleotides that are part of the motifs, may be modified. Each nucleotide may be modified with the same or different modification which can include one or more alteration of one or both of the non-linking phosphate oxygens or of one or more of the linking phosphate oxygens; alteration of a constituent of the ribose sugar, e.g., of the 2′-hydroxyl on the ribose sugar; wholesale replacement of the phosphate moiety with “dephospho” linkers; modification or replacement of a naturally occurring base; and replacement or modification of the ribose-phosphate backbone.

As nucleic acids are polymers of subunits, many of the modifications occur at a position which is repeated within a nucleic acid, e.g., a modification of a base, or a phosphate moiety, or a non-linking O of a phosphate moiety. In some cases the modification will occur at all of the subject positions in the nucleic acid but in many cases it will not. By way of example, a modification may only occur at a 3′- or 5′ terminal position, may only occur in a terminal region, e.g., at a position on a terminal nucleotide or in the last 2, 3, 4, 5, or 10 nucleotides of a strand. A modification may occur in a double strand region, a single strand region, or in both. A modification may occur only in the double strand region of an RNA or may only occur in a single strand region of a RNA. For example, a phosphorothioate modification at a non-linking O position may only occur at one or both termini, may only occur in a terminal region, e.g., at a position on a terminal nucleotide or in the last 2, 3, 4, 5, or 10 nucleotides of a strand, or may occur in double strand and single strand regions, particularly at termini. The 5′-end or ends can be phosphorylated.

It may be possible, e.g., to enhance stability, to include particular bases in overhangs, or to include modified nucleotides or nucleotide surrogates, in single strand overhangs, e.g., in a 5′- or 3′-overhang, or in both. For example, it can be desirable to include purine nucleotides in overhangs. In some embodiments all or some of the bases in a 3′- or 5′-overhang may be modified, e.g., with a modification described herein. Modifications can include, e.g., the use of modifications at the 2′ position of the ribose sugar with modifications that are known in the art, e.g., the use of deoxyribonucleotides, 2′-deoxy-2′-fluoro (2′-F) or 2′-O-methyl modified instead of the ribosugar of the nucleobase, and modifications in the phosphate group, e.g., phosphorothioate modifications. Overhangs need not be homologous with the target sequence.

In some embodiments, each residue of the sense strand and antisense strand is independently modified with LNA, CRN, cET, UNA, HNA, CeNA, 2′-methoxyethyl, 2′-O-methyl, 2′-O-allyl, 2′-C-allyl, 2′-deoxy, 2′-hydroxyl, or 2′-fluoro. The strands can contain more than one modification. In one embodiment, each residue of the sense strand and antisense strand is independently modified with 2′-O-methyl or 2′-fluoro.

At least two different modifications are typically present on the sense strand and antisense strand. Those two modifications may be the 2′-O-methyl or 2′-fluoro modifications, or others.

In certain embodiments, the N_aor N_bcomprise modifications of an alternating pattern. The term “alternating motif” as used herein refers to a motif having one or more modifications, each modification occurring on alternating nucleotides of one strand. The alternating nucleotide may refer to one per every other nucleotide or one per every three nucleotides, or a similar pattern. For example, if A, B and C each represent one type of modification to the nucleotide, the alternating motif can be “ABABABABABAB . . . ,” “AABBAABBAABB . . . ,” “AABAABAABAAB . . . ,” “AAABAAABAAAB . . . ,” “AAABBBAAABBB . . . ,” or “ABCABCABCABC . . . ,” etc.

The type of modifications contained in the alternating motif may be the same or different. For example, if A, B, C, D each represent one type of modification on the nucleotide, the alternating pattern, i.e., modifications on every other nucleotide, may be the same, but each of the sense strand or antisense strand can be selected from several possibilities of modifications within the alternating motif such as “ABABAB . . . ”, “ACACAC . . . ” “BDBDBD . . . ” or “CDCDCD . . . ,” etc.

In some embodiments, the dsRNAi agent of the invention comprises the modification pattern for the alternating motif on the sense strand relative to the modification pattern for the alternating motif on the antisense strand is shifted. The shift may be such that the modified group of nucleotides of the sense strand corresponds to a differently modified group of nucleotides of the antisense strand and vice versa. For example, the sense strand when paired with the antisense strand in the dsRNA duplex, the alternating motif in the sense strand may start with “ABABAB” from 5′ to 3′ of the strand and the alternating motif in the antisense strand may start with “BABABA” from 5′ to 3′ of the strand within the duplex region. As another example, the alternating motif in the sense strand may start with “AABBAABB” from 5′ to 3′ of the strand and the alternating motif in the antisense strand may start with “BBAABBAA” from 5′ to 3′ of the strand within the duplex region, so that there is a complete or partial shift of the modification patterns between the sense strand and the antisense strand.

In some embodiments, the dsRNAi agent comprises the pattern of the alternating motif of 2′-O-methyl modification and 2′-F modification on the sense strand initially has a shift relative to the pattern of the alternating motif of 2′-O-methyl modification and 2′-F modification on the antisense strand initially, i.e., the 2′-O-methyl modified nucleotide on the sense strand base pairs with a 2′-F modified nucleotide on the antisense strand and vice versa. The 1 position of the sense strand may start with the 2′-F modification, and the 1 position of the antisense strand may start with the 2′-O-methyl modification.

The introduction of one or more motifs of three identical modifications on three consecutive nucleotides to the sense strand or antisense strand interrupts the initial modification pattern present in the sense strand or antisense strand. This interruption of the modification pattern of the sense or antisense strand by introducing one or more motifs of three identical modifications on three consecutive nucleotides to the sense or antisense strand may enhance the gene silencing activity against the target gene.

In some embodiments, when the motif of three identical modifications on three consecutive nucleotides is introduced to any of the strands, the modification of the nucleotide next to the motif is a different modification than the modification of the motif. For example, the portion of the sequence containing the motif is “ . . . N_aYYYN_b. . . ,” where “Y” represents the modification of the motif of three identical modifications on three consecutive nucleotide, and “N_a” and “N_b” represent a modification to the nucleotide next to the motif “YYY” that is different than the modification of Y, and where N_aand N_bcan be the same or different modifications. Alternatively, N_aor N_bmay be present or absent when there is a wing modification present.

The iRNA may further comprise at least one phosphorothioate or methylphosphonate internucleotide linkage. The phosphorothioate or methylphosphonate internucleotide linkage modification may occur on any nucleotide of the sense strand, antisense strand, or both strands in any position of the strand. For instance, the internucleotide linkage modification may occur on every nucleotide on the sense strand or antisense strand; each internucleotide linkage modification may occur in an alternating pattern on the sense strand or antisense strand; or the sense strand or antisense strand may contain both internucleotide linkage modifications in an alternating pattern. The alternating pattern of the internucleotide linkage modification on the sense strand may be the same or different from the antisense strand, and the alternating pattern of the internucleotide linkage modification on the sense strand may have a shift relative to the alternating pattern of the internucleotide linkage modification on the antisense strand. In one embodiment, a double-stranded RNAi agent comprises 6-8 phosphorothioate internucleotide linkages. In some embodiments, the antisense strand comprises two phosphorothioate internucleotide linkages at the 5′-end and two phosphorothioate internucleotide linkages at the 3′-end, and the sense strand comprises at least two phosphorothioate internucleotide linkages at either the 5′-end or the 3′-end.

In some embodiments, the dsRNAi agent comprises a phosphorothioate or methylphosphonate internucleotide linkage modification in the overhang region. For example, the overhang region may contain two nucleotides having a phosphorothioate or methylphosphonate internucleotide linkage between the two nucleotides. Internucleotide linkage modifications also may be made to link the overhang nucleotides with the terminal paired nucleotides within the duplex region. For example, at least 2, 3, 4, or all the overhang nucleotides may be linked through phosphorothioate or methylphosphonate internucleotide linkage, and optionally, there may be additional phosphorothioate or methylphosphonate internucleotide linkages linking the overhang nucleotide with a paired nucleotide that is next to the overhang nucleotide. For instance, there may be at least two phosphorothioate internucleotide linkages between the terminal three nucleotides, in which two of the three nucleotides are overhang nucleotides, and the third is a paired nucleotide next to the overhang nucleotide. These terminal three nucleotides may be at the 3′-end of the antisense strand, the 3′-end of the sense strand, the 5′-end of the antisense strand, or the 5′ end of the antisense strand.

In some embodiments, the 2-nucleotide overhang is at the 3′-end of the antisense strand, and there are two phosphorothioate internucleotide linkages between the terminal three nucleotides, wherein two of the three nucleotides are the overhang nucleotides, and the third nucleotide is a paired nucleotide next to the overhang nucleotide. Optionally, the dsRNAi agent may additionally have two phosphorothioate internucleotide linkages between the terminal three nucleotides at both the 5′-end of the sense strand and at the 5′-end of the antisense strand.

In one embodiment, the dsRNAi agent comprises mismatch(es) with the target, within the duplex, or combinations thereof. The mismatch may occur in the overhang region or the duplex region. The base pair may be ranked on the basis of their propensity to promote dissociation or melting (e.g., on the free energy of association or dissociation of a particular pairing, the simplest approach is to examine the pairs on an individual pair basis, though next neighbor or similar analysis can also be used). In terms of promoting dissociation: A:U is preferred over G:C; G:U is preferred over G:C; and I:C is preferred over G:C (I=inosine). Mismatches, e.g., non-canonical or other than canonical pairings (as described elsewhere herein) are preferred over canonical (A:T, A:U, G:C) pairings; and pairings which include a universal base are preferred over canonical pairings.

In certain embodiments, the dsRNAi agent comprises at least one of the first 1, 2, 3, 4, or 5 base pairs within the duplex regions from the 5′-end of the antisense strand independently selected from the group of: A:U, G:U, I:C, and mismatched pairs, e.g., non-canonical or other than canonical pairings or pairings which include a universal base, to promote the dissociation of the antisense strand at the 5′-end of the duplex.

In certain embodiments, the nucleotide at the 1 position within the duplex region from the 5′-end in the antisense strand is selected from A, dA, dU, U, and dT. Alternatively, at least one of the first 1, 2, or 3 base pair within the duplex region from the 5′-end of the antisense strand is an AU base pair. For example, the first base pair within the duplex region from the 5′-end of the antisense strand is an AU base pair.

In other embodiments, the nucleotide at the 3′-end of the sense strand is deoxythimidine (dT) or the nucleotide at the 3′-end of the antisense strand is deoxythimidine (dT). For example, there is a short sequence of deoxythimidine nucleotides, for example, two dT nucleotides on the 3′-end of the sense, antisense strand, or both strands.

In certain embodiments, the sense strand sequence may be represented by formula (I):

(I)

5′ n_p-N_a-(X X X)_i-N_b-Y Y Y -N_b-(Z Z Z )_j-N_a-n_q 3′

wherein:

- i and j are each independently 0 or 1;
- p and q are each independently 0-6;
- each N_aindependently represents an oligonucleotide sequence comprising 0-25 modified nucleotides, each sequence comprising at least two differently modified nucleotides;
- each N_bindependently represents an oligonucleotide sequence comprising 0-10 modified nucleotides;
- each n_pand n_qindependently represent an overhang nucleotide;
- wherein Nb and Y do not have the same modification; and
- XXX, YYY, and ZZZ each independently represent one motif of three identical modifications on three consecutive nucleotides. In one embodiment, YYY is all 2′-F modified nucleotides.

In some embodiments, the N_aor N_bcomprises modifications of alternating pattern.

In some embodiments, the YYY motif occurs at or near the cleavage site of the sense strand. For example, when the dsRNAi agent has a duplex region of 17-23 nucleotides in length, the YYY motif can occur at or the vicinity of the cleavage site (e.g.: can occur at positions 6, 7, 8; 7, 8, 9; 8, 9, 10; 9, 10, 11; 10, 11,12; or 11, 12, 13) of the sense strand, the count starting from the first nucleotide, from the 5′-end; or optionally, the count starting at the first paired nucleotide within the duplex region, from the 5′-end.

In one embodiment, i is 1 and j is 0, or i is 0 and j is 1, or both i and j are 1. The sense strand can therefore be represented by the following formulas:

(Ib)

5′ n_p-N_a-YYY-N_b-ZZZ-N_a-n_q 3′;

(Ic)

5′ n_p-N_a-XXX-N_b-YYY-N_a-n_q 3′;

or

(Id)

5′ n_p-N_a-XXX-N_b-YYY-N_b-ZZZ-N_a-n_q 3′.

When the sense strand is represented by formula (Ib), N_brepresents an oligonucleotide sequence comprising 0-10, 0-7, 0-5, 0-4, 0-2, or 0 modified nucleotides. Each N_aindependently can represent an oligonucleotide sequence comprising 2-20, 2-15, or 2-10 modified nucleotides.

When the sense strand is represented as formula (Ic), N_brepresents an oligonucleotide sequence comprising 0-10, 0-7, 0-10, 0-7, 0-5, 0-4, 0-2, or 0 modified nucleotides. Each N_acan independently represent an oligonucleotide sequence comprising 2-20, 2-15, or 2-10 modified nucleotides.

When the sense strand is represented as formula (Id), each N_bindependently represents an oligonucleotide sequence comprising 0-10, 0-7, 0-5, 0-4, 0-2, or 0 modified nucleotides. In one embodiment, N_bis 0, 1, 2, 3, 4, 5, or 6 Each N_acan independently represent an oligonucleotide sequence comprising 2-20, 2-15, or 2-10 modified nucleotides.

Each of X, Y and Z may be the same or different from each other.

In other embodiments, i is 0 and j is 0, and the sense strand may be represented by the formula:

(Ia)

5′ n_p-N_a-YYY-N_a-n_q 3′.

When the sense strand is represented by formula (Ia), each N_aindependently can represent an oligonucleotide sequence comprising 2-20, 2-15, or 2-10 modified nucleotides.

In one embodiment, the antisense strand sequence of the RNAi may be represented by formula (II):

(II)

5′ n_q′-N_a′-(Z′Z′Z)_k-N_b′-Y′Y′Y′-N_b′-(X′X′X′)_i-N′_a-

n_p′ 3′

wherein:

- k and l are each independently 0 or 1;
- p′ and q′ are each independently 0-6;
- each N_a′ independently represents an oligonucleotide sequence comprising 0-25 modified nucleotides, each sequence comprising at least two differently modified nucleotides;
- each N_b′ independently represents an oligonucleotide sequence comprising 0-10 modified nucleotides;
- each n_p′ and n_q′ independently represent an overhang nucleotide;
- wherein N_b′ and Y′ do not have the same modification; and
- X′X′X′, Y′Y′Y′, and Z′Z′Z′ each independently represent one motif of three identical modifications on three consecutive nucleotides.

In some embodiments, the N_a′ or N_b′ comprises modifications of alternating pattern.

The Y′Y′Y′ motif occurs at or near the cleavage site of the antisense strand. For example, when the dsRNAi agent has a duplex region of 17-23 nucleotides in length, the Y′Y′Y′ motif can occur at positions 9, 10, 11; 10, 11, 12; 11, 12, 13; 12, 13, 14; or 13, 14, 15 of the antisense strand, with the count starting from the first nucleotide, from the 5′-end; or optionally, the count starting at the first paired nucleotide within the duplex region, from the 5′-end. In one embodiment, the Y′Y′Y′ motif occurs at positions 11, 12, 13.

In certain embodiments, Y′Y′Y′ motif is all 2′-OMe modified nucleotides.

In certain embodiments, k is 1 and l is 0, or k is 0 and l is 1, or both k and l are 1.

The antisense strand can therefore be represented by the following formulas:

(IIb)

5′ n_q′-N_a′-Z′Z′Z′-N_b′-Y′Y′Y′-N_a′-n_p 3′;

(IIc)

5′ n_a′-N_a′-Y′Y′Y′-N_b′-X′X′X′-n_p′ 3′;

or

(IId)

5′ n_q′-N_a′- Z′Z′Z′-N_b′-Y′Y′Y′-N_b′- X′X′X′-

N_a′-n_p 3′.

When the antisense strand is represented by formula (IIb), N_b′ represents an oligonucleotide sequence comprising 0-10, 0-7, 0-10, 0-7, 0-5, 0-4, 0-2, or 0 modified nucleotides. Each N_a′ independently represents an oligonucleotide sequence comprising 2-20, 2-15, or 2-10 modified nucleotides.

When the antisense strand is represented as formula (IIC), N_b′ represents an oligonucleotide sequence comprising 0-10, 0-7, 0-10, 0-7, 0-5, 0-4, 0-2, or 0 modified nucleotides. Each N_a′ independently represents an oligonucleotide sequence comprising 2-20, 2-15, or 2-10 modified nucleotides.

When the antisense strand is represented as formula (IId), each N_b′ independently represents an oligonucleotide sequence comprising 0-10, 0-7, 0-10, 0-7, 0-5, 0-4, 0-2, or 0 modified nucleotides. Each N_a′ independently represents an oligonucleotide sequence comprising 2-20, 2-15, or 2-10 modified nucleotides. In one embodiment, N_bis 0, 1, 2, 3, 4, 5, or 6.

In other embodiments, k is 0 and l is 0 and the antisense strand may be represented by the formula:

(Ia)

5′ n_p′-N_a′-Y′Y′Y′- N_a′-n_q′ 3′.

When the antisense strand is represented as formula (IIa), each N_a′ independently represents an oligonucleotide sequence comprising 2-20, 2-15, or 2-10 modified nucleotides. Each of X′, Y′ and Z′ may be the same or different from each other.

Each nucleotide of the sense strand and antisense strand may be independently modified with LNA, CRN, UNA, cEt, HNA, CeNA, 2′-methoxyethyl, 2′-O-methyl, 2′-O-allyl, 2′-C-allyl, 2′-hydroxyl, or 2′-fluoro. For example, each nucleotide of the sense strand and antisense strand is independently modified with 2′-O-methyl or 2′-fluoro. Each X, Y, Z, X′, Y′, and Z′, in particular, may represent a 2′-O-methyl modification or a 2′-fluoro modification.

In some embodiments, the sense strand of the dsRNAi agent may contain YYY motif occurring at 9, 10, and 11 positions of the strand when the duplex region is 21 nt, the count starting from the first nucleotide from the 5′-end, or optionally, the count starting at the first paired nucleotide within the duplex region, from the 5′-end; and Y represents 2′-F modification. The sense strand may additionally contain XXX motif or ZZZ motifs as wing modifications at the opposite end of the duplex region; and XXX and ZZZ each independently represents a 2′-OMe modification or 2′-F modification.

In some embodiments the antisense strand may contain Y′Y′Y′ motif occurring at positions 11, 12, 13 of the strand, the count starting from the first nucleotide from the 5′-end, or optionally, the count starting at the first paired nucleotide within the duplex region, from the 5′-end; and Y′ represents 2′-O-methyl modification. The antisense strand may additionally contain X′X′X′ motif or Z′Z′Z′ motifs as wing modifications at the opposite end of the duplex region; and X′X′X′ and Z′Z′Z′ each independently represents a 2′-OMe modification or 2′-F modification.

The sense strand represented by any one of the above formulas (Ia), (Ib), (Ic), and (Id) forms a duplex with an antisense strand being represented by any one of formulas (IIa), (IIb), (IIc), and (IId), respectively.

Accordingly, the dsRNAi agents for use in the methods of the invention may comprise a sense strand and an antisense strand, each strand having 14 to 30 nucleotides, the iRNA duplex represented by formula (III):

(III)

sense:

5′ n_p-N_a-(X X X)_i-N_b-Y Y Y -N_b-(Z Z Z)_j-N_a-n_q 3′

antisense:

3′ n_p′-N_a′-(X′X′X′)_k-N_b′-Y′Y′Y′-N_b′-(Z′Z′Z′)_l-

N_a′-n_q 5′

wherein:

- j, k, and l are each independently 0 or 1;
- p, p′, q, and q′ are each independently 0-6;
- each N_aand N_a′ independently represents an oligonucleotide sequence comprising 0-25 modified nucleotides, each sequence comprising at least two differently modified nucleotides;
- each N_band N_b′ independently represents an oligonucleotide sequence comprising 0-10 modified nucleotides;
- wherein each n_p′, n_p, n_q′, and n_q, each of which may or may not be present, independently represents an overhang nucleotide; and
- XXX, YYY, ZZZ, X′X′X′, Y′Y′Y′, and Z′Z′Z′ each independently represent one motif of three identical modifications on three consecutive nucleotides.

In one embodiment, i is 0 and j is 0; or i is 1 and j is 0; or i is 0 and j is 1; or both i and j are 0; or both i and j are 1. In another embodiment, k is 0 and l is 0; or k is 1 and l is 0; k is 0 and l is 1; or both k and l are 0; or both k and l are 1.

Exemplary combinations of the sense strand and antisense strand forming an iRNA duplex include the formulas below:

(IIIa)

5′ n_p- N_a-Y Y Y-N_a-n_q 3′

3′ n_p′-N_a′-Y′Y′Y -N_a′n_q′ 5′

(IIIb)

5′ n_p-N_a-Y Y Y -N_b-Z Z Z -N_a-n_q 3′

3′ n_p′-N_a′-Y′Y′Y′-N_b′-Z′Z′Z′-N_a′n_q′ 5′

(IIIc)

5′ n_p-N_a- X X X -N_b-Y Y Y - N_a-n_q 3′

3′ n_p′-N_a′-X′X′X′-N_b′-Y′Y′Y′-N_a′-n_q′ 5′

(IIId)

5′ n_p-N_a-X X X -N_b-Y Y Y -N_b-Z Z Z -N_a-n_q 3′

3′ n_p′-N_a′-X′X′X′-N_b′-Y′Y′Y′-N_b′-Z′Z′Z′-N_a-n_q′ 5′

When the dsRNAi agent is represented by formula (IIIa), each N_aindependently represents an oligonucleotide sequence comprising 2-20, 2-15, or 2-10 modified nucleotides.

When the dsRNAi agent is represented by formula (IIIb), each N_bindependently represents an oligonucleotide sequence comprising 1-10, 1-7, 1-5, or 1-4 modified nucleotides. Each N_aindependently represents an oligonucleotide sequence comprising 2-20, 2-15, or 2-10 modified nucleotides.

When the dsRNAi agent is represented as formula (IIIc), each N_b, N_b′ independently represents an oligonucleotide sequence comprising 0-10, 0-7, 0-10, 0-7, 0-5, 0-4, 0-2, or 0 modified nucleotides. Each N_aindependently represents an oligonucleotide sequence comprising 2-20, 2-15, or 2-10 modified nucleotides.

When the dsRNAi agent is represented as formula (IIId), each N_b, N_b′ independently represents an oligonucleotide sequence comprising 0-10, 0-7, 0-10, 0-7, 0-5, 0-4, 0-2, or 0 modified nucleotides. Each N_a, N_a′ independently represents an oligonucleotide sequence comprising 2-20, 2-15, or 2-10 modified nucleotides. Each of N_a, N_a′, N_b, and N_b′ independently comprises modifications of alternating pattern.

Each of X, Y, and Z in formulas (III), (IIIa), (IIIb), (IIIc), and (IIId) may be the same or different from each other.

When the dsRNAi agent is represented by formula (III), (IIIa), (IIIb), (IIIc), and (IIId), at least one of the Y nucleotides may form a base pair with one of the Y′ nucleotides. Alternatively, at least two of the Y nucleotides form base pairs with the corresponding Y′ nucleotides; or all three of the Y nucleotides all form base pairs with the corresponding Y′ nucleotides.

When the dsRNAi agent is represented by formula (IIIb) or (IIId), at least one of the Z nucleotides may form a base pair with one of the Z′ nucleotides. Alternatively, at least two of the Z nucleotides form base pairs with the corresponding Z′ nucleotides; or all three of the Z nucleotides all form base pairs with the corresponding Z′ nucleotides.

When the dsRNAi agent is represented as formula (IIIc) or (IIId), at least one of the X nucleotides may form a base pair with one of the X′ nucleotides. Alternatively, at least two of the X nucleotides form base pairs with the corresponding X′ nucleotides; or all three of the X nucleotides all form base pairs with the corresponding X′ nucleotides.

In certain embodiments, the modification on the Y nucleotide is different than the modification on the Y′ nucleotide, the modification on the Z nucleotide is different than the modification on the Z′ nucleotide, or the modification on the X nucleotide is different than the modification on the X′ nucleotide.

In certain embodiments, when the dsRNAi agent is represented by formula (IIId), the N_amodifications are 2′-O-methyl or 2′-fluoro modifications. In other embodiments, when the RNAi agent is represented by formula (IIId), the N_amodifications are 2′-O-methyl or 2′-fluoro modifications and n_p′>0 and at least one n_p′ is linked to a neighboring nucleotide a via phosphorothioate linkage. In yet other embodiments, when the RNAi agent is represented by formula (IIId), the N_amodifications are 2′-O-methyl or 2′-fluoro modifications, n_p′>0 and at least one n_p′ is linked to a neighboring nucleotide via phosphorothioate linkage, and the sense strand is conjugated to one or more GalNAc derivatives attached through a bivalent or trivalent branched linker (described below). In other embodiments, when the RNAi agent is represented by formula (IIId), the N_amodifications are 2′-O-methyl or 2′-fluoro modifications, n_p′>0 and at least one n_p′ is linked to a neighboring nucleotide via phosphorothioate linkage, the sense strand comprises at least one phosphorothioate linkage, and the sense strand is conjugated to one or more GalNAc derivatives attached through a bivalent or trivalent branched linker.

In some embodiments, when the dsRNAi agent is represented by formula (IIIa), the N_amodifications are 2′-O-methyl or 2′-fluoro modifications, n_p′>0 and at least one n_p′ is linked to a neighboring nucleotide via phosphorothioate linkage, the sense strand comprises at least one phosphorothioate linkage, and the sense strand is conjugated to one or more GalNAc derivatives attached through a bivalent or trivalent branched linker.

In some embodiments, the dsRNAi agent is a multimer containing at least two duplexes represented by formula (III), (IIIa), (IIIb), (IIIc), and (IIId), wherein the duplexes are connected by a linker. The linker can be cleavable or non-cleavable. Optionally, the multimer further comprises a ligand. Each of the duplexes can target the same gene or two different genes; or each of the duplexes can target same gene at two different target sites.

In some embodiments, the dsRNAi agent is a multimer containing three, four, five, six, or more duplexes represented by formula (III), (IIIa), (IIIb), (IIIc), and (IIId), wherein the duplexes are connected by a linker. The linker can be cleavable or non-cleavable. Optionally, the multimer further comprises a ligand. Each of the duplexes can target the same gene or two different genes; or each of the duplexes can target same gene at two different target sites.

In one embodiment, two dsRNAi agents represented by at least one of formulas (III), (IIIa), (IIIb), (IIIc), and (IIId) are linked to each other at the 5′ end, and one or both of the 3′ ends, and are optionally conjugated to a ligand. Each of the agents can target the same gene or two different genes; or each of the agents can target same gene at two different target sites.

In certain embodiments, an RNAi agent of the invention may contain a low number of nucleotides containing a 2′-fluoro modification, e.g., 10 or fewer nucleotides with 2′-fluoro modification. For example, the RNAi agent may contain 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 or 0 nucleotides with a 2′-fluoro modification. In a specific embodiment, the RNAi agent of the invention contains 10 nucleotides with a 2′-fluoro modification, e.g., 4 nucleotides with a 2′-fluoro modification in the sense strand and 6 nucleotides with a 2′-fluoro modification in the antisense strand. In another specific embodiment, the RNAi agent of the invention contains 6 nucleotides with a 2′-fluoro modification, e.g., 4 nucleotides with a 2′-fluoro modification in the sense strand and 2 nucleotides with a 2′-fluoro modification in the antisense strand.

In other embodiments, an RNAi agent of the invention may contain an ultra low number of nucleotides containing a 2′-fluoro modification, e.g., 2 or fewer nucleotides containing a 2′-fluoro modification. For example, the RNAi agent may contain 2, 1 of 0 nucleotides with a 2′-fluoro modification. In a specific embodiment, the RNAi agent may contain 2 nucleotides with a 2′-fluoro modification, e.g., 0 nucleotides with a 2-fluoro modification in the sense strand and 2 nucleotides with a 2′-fluoro modification in the antisense strand.

Various publications describe multimeric iRNAs that can be used in the methods of the invention. Such publications include WO2007/091269, U.S. Pat. No. 7,858,769, WO2010/141511, WO2007/117686, WO2009/014887, and WO2011/031520 the entire contents of each of which are hereby incorporated herein by reference.

In certain embodiments, the compositions and methods of the disclosure include a vinyl phosphonate (VP) modification of an RNAi agent as described herein. In exemplary embodiments, a 5′ vinyl phosphonate modified nucleotide of the disclosure has the structure:

embedded image

wherein X is O or S;

- R is hydrogen, hydroxy, fluoro, or C_1-20alkoxy (e.g., methoxy or n-hexadecyloxy);
- R⁵′ is ═C(H)—P(O)(OH)₂and the double bond between the C5′ carbon and R⁵′ is in the E or Z orientation (e.g., E orientation); and
- B is a nucleobase or a modified nucleobase, optionally where B is adenine, guanine, cytosine, thymine, or uracil.

A vinyl phosphonate of the instant disclosure may be attached to either the antisense or the sense strand of a dsRNA of the disclosure. In certain embodiments, a vinyl phosphonate of the instant disclosure is attached to the antisense strand of a dsRNA, optionally at the 5′ end of the antisense strand of the dsRNA.

Vinyl phosphonate modifications are also contemplated for the compositions and methods of the instant disclosure. An exemplary vinyl phosphonate structure includes the preceding structure, where R5′ is ═C(H)—OP(O)(OH)2 and the double bond between the C5′ carbon and R5′ is in the E or Z orientation (e.g., E orientation).

As described in more detail below, the iRNA that contains conjugations of one or more carbohydrate moieties to an iRNA can optimize one or more properties of the iRNA. In many cases, the carbohydrate moiety will be attached to a modified subunit of the iRNA. For example, the ribose sugar of one or more ribonucleotide subunits of a iRNA can be replaced with another moiety, e.g., a non-carbohydrate (such as, cyclic) carrier to which is attached a carbohydrate ligand. A ribonucleotide subunit in which the ribose sugar of the subunit has been so replaced is referred to herein as a ribose replacement modification subunit (RRMS). A cyclic carrier may be a carbocyclic ring system, i.e., all ring atoms are carbon atoms, or a heterocyclic ring system, i.e., one or more ring atoms may be a heteroatom, e.g., nitrogen, oxygen, sulfur. The cyclic carrier may be a monocyclic ring system, or may contain two or more rings, e.g. fused rings. The cyclic carrier may be a fully saturated ring system, or it may contain one or more double bonds.

The ligand may be attached to the polynucleotide via a carrier. The carriers include (i) at least one “backbone attachment point,” such as, two “backbone attachment points” and (ii) at least one “tethering attachment point.” A “backbone attachment point” as used herein refers to a functional group, e.g. a hydroxyl group, or generally, a bond available for, and that is suitable for incorporation of the carrier into the backbone, e.g., the phosphate, or modified phosphate, e.g., sulfur containing, backbone, of a ribonucleic acid. A “tethering attachment point” (TAP) in some embodiments refers to a constituent ring atom of the cyclic carrier, e.g., a carbon atom or a heteroatom (distinct from an atom which provides a backbone attachment point), that connects a selected moiety. The moiety can be, e.g., a carbohydrate, e.g. monosaccharide, disaccharide, trisaccharide, tetrasaccharide, oligosaccharide, or polysaccharide. Optionally, the selected moiety is connected by an intervening tether to the cyclic carrier. Thus, the cyclic carrier will often include a functional group, e.g., an amino group, or generally, provide a bond, that is suitable for incorporation or tethering of another chemical entity, e.g., a ligand to the constituent ring.

The iRNA may be conjugated to a ligand via a carrier, wherein the carrier can be cyclic group or acyclic group. In one embodiment, the cyclic group is selected from pyrrolidinyl, pyrazolinyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, piperidinyl, piperazinyl, [1,3]dioxolane, oxazolidinyl, isoxazolidinyl, morpholinyl, thiazolidinyl, isothiazolidinyl, quinoxalinyl, pyridazinonyl, tetrahydrofuryl, and decalin. In one embodiment, the acyclic group is a serinol backbone or diethanolamine backbone.

i. Thermally Destabilizing Modifications

In certain embodiments, a dsRNA molecule can be optimized for RNA interference by incorporating thermally destabilizing modifications in the seed region of the antisense strand. As used herein “seed region” means at positions 2-9 of the 5′-end of the referenced strand or at positions 2-8 of the 5′-end of the referenced strand. For example, thermally destabilizing modifications can be incorporated in the seed region of the antisense strand to reduce or inhibit off-target gene silencing.

The term “thermally destabilizing modification(s)” includes modification(s) that would result with a dsRNA with a lower overall melting temperature (T_m) than the T_mof the dsRNA without having such modification(s). For example, the thermally destabilizing modification(s) can decrease the T_mof the dsRNA by 1-4° C., such as one, two, three or four degrees Celcius. And, the term “thermally destabilizing nucleotide” refers to a nucleotide containing one or more thermally destabilizing modifications.

It has been discovered that dsRNAs with an antisense strand comprising at least one thermally destabilizing modification of the duplex within the first 9 nucleotide positions, counting from the 5′ end, of the antisense strand have reduced off-target gene silencing activity. Accordingly, in some embodiments, the antisense strand comprises at least one (e.g., one, two, three, four, five or more) thermally destabilizing modification of the duplex within the first 9 nucleotide positions of the 5′ region of the antisense strand. In some embodiments, one or more thermally destabilizing modification(s) of the duplex is/are located in positions 2-9, such as, positions 4-8, from the 5′-end of the antisense strand. In some further embodiments, the thermally destabilizing modification(s) of the duplex is/are located at position 6, 7 or 8 from the 5′-end of the antisense strand. In still some further embodiments, the thermally destabilizing modification of the duplex is located at position 7 from the 5′-end of the antisense strand. In some embodiments, the thermally destabilizing modification of the duplex is located at position 2, 3, 4, 5 or 9 from the 5′-end of the antisense strand.

An iRNA agent comprises a sense strand and an antisense strand, each strand having 14 to 40 nucleotides. The RNAi agent may be represented by formula (L):

embedded image

In formula (L), B1, B2, B3, B1′, B2′, B3′, and B4′ each are independently a nucleotide containing a modification selected from the group consisting of 2′-O-alkyl, 2′-substituted alkoxy, 2′-substituted alkyl, 2′-halo, ENA, and BNA/LNA. In one embodiment, B1, B2, B3, B1′, B2′, B3′, and B4′ each contain 2′-OMe modifications. In one embodiment, B1, B2, B3, B1′, B2′, B3′, and B4′ each contain 2′-OMe or 2′-F modifications. In one embodiment, at least one of B1, B2, B3, B1′, B2′, B3′, and B4′ contain 2′-O—N-methylacetamido (2′-O—NMA, 2′O—CH2C(O)N(Me)H) modification.

C1 is a thermally destabilizing nucleotide placed at a site opposite to the seed region of the antisense strand (i.e., at positions 2-8 of the 5′-end of the antisense strand, or at positions 2-9 of the 5′-end of the antisense strand). For example, C1 is at a position of the sense strand that pairs with a nucleotide at positions 2-8 of the 5′-end of the antisense strand. In one example, C1 is at position 15 from the 5′-end of the sense strand. C1 nucleotide bears the thermally destabilizing modification which can include abasic modification; mismatch with the opposing nucleotide in the duplex; and sugar modification such as 2′-deoxy modification or acyclic nucleotide e.g., unlocked nucleic acids (UNA) or glycerol nucleic acid (GNA), or 2′-5′-linked ribonucleotides (“3′-RNA”). In one embodiment, C1 has thermally destabilizing modification selected from the group consisting of: i) mismatch with the opposing nucleotide in the antisense strand; ii) abasic modification selected from the group consisting of:

embedded image

and iii) sugar modification selected from the group consisting of:

embedded image

wherein B is a modified or unmodified nucleobase, R¹and R²independently are H, halogen, OR₃, or alkyl; and R₃is H, alkyl, cycloalkyl, aryl, aralkyl, heteroaryl or sugar. In one embodiment, the thermally destabilizing modification in Cl is a mismatch selected from the group consisting of G:G, G:A, G:U, G:T, A:A, A:C, C:C, C:U, C:T, U:U, T:T, and U:T; and optionally, at least one nucleobase in the mismatch pair is a 2′-deoxy nucleobase. In one example, the thermally destabilizing modification in Cl is GNA or

embedded image

T1, T1′, T2′, and T3′ each independently represent a nucleotide comprising a modification providing the nucleotide a steric bulk that is less or equal to the steric bulk of a 2′-OMe modification. A steric bulk refers to the sum of steric effects of a modification. Methods for determining steric effects of a modification of a nucleotide are known to one skilled in the art. The modification can be at the 2′ position of a ribose sugar of the nucleotide, or a modification to a non-ribose nucleotide, acyclic nucleotide, or the backbone of the nucleotide that is similar or equivalent to the 2′ position of the ribose sugar, and provides the nucleotide a steric bulk that is less than or equal to the steric bulk of a 2′-OMe modification. For example, T1, T1′, T2′, and T3′ are each independently selected from DNA, RNA, LNA, 2′-F, and 2′-F-5′-methyl. In one embodiment, T1 is DNA. In one embodiment, T1′ is DNA, RNA or LNA. In one embodiment, T2′ is DNA or RNA. In one embodiment, T3′ is DNA or RNA.

- n¹, n³, and q¹are independently 4 to 15 nucleotides in length.
- n⁵, q³, and q⁷are independently 1-6 nucleotide(s) in length.
- n⁴, q², and q⁶are independently 1-3 nucleotide(s) in length; alternatively, n⁴is 0.
- q⁵is independently 0-10 nucleotide(s) in length.
- n²and q⁴are independently 0-3 nucleotide(s) in length.

Alternatively, n⁴is 0-3 nucleotide(s) in length.

In one embodiment, n⁴can be 0. In one example, n⁴is 0, and q²and q⁶are 1. In another example, n⁴is 0, and q²and q⁶are 1, with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand).

In one embodiment, n⁴, q², and q⁶are each 1.

In one embodiment, n², n⁴, q², q⁴, and q⁶are each 1.

In one embodiment, C1 is at position 14-17 of the 5′-end of the sense strand, when the sense strand is 19-22 nucleotides in length, and n⁴is 1. In one embodiment, C1 is at position 15 of the 5′-end of the sense strand

In one embodiment, T3′ starts at position 2 from the 5′ end of the antisense strand. In one example, T3′ is at position 2 from the 5′ end of the antisense strand and q⁶is equal to 1.

In one embodiment, T1′ starts at position 14 from the 5′ end of the antisense strand. In one example, T1′ is at position 14 from the 5′ end of the antisense strand and q²is equal to 1.

In an exemplary embodiment, T3′ starts from position 2 from the 5′ end of the antisense strand and T1′ starts from position 14 from the 5′ end of the antisense strand. In one example, T3′ starts from position 2 from the 5′ end of the antisense strand and q⁶is equal to 1 and T1′ starts from position 14 from the 5′ end of the antisense strand and q²is equal to 1.

In one embodiment, T1′ and T3′ are separated by 11 nucleotides in length (i.e. not counting the T1′ and T3′ nucleotides).

In one embodiment, T1′ is at position 14 from the 5′ end of the antisense strand. In one example, T1′ is at position 14 from the 5′ end of the antisense strand and q²is equal to 1, and the modification at the 2′ position or positions in a non-ribose, acyclic or backbone that provide less steric bulk than a 2′-OMe ribose.

In one embodiment, T3′ is at position 2 from the 5′ end of the antisense strand. In one example, T3′ is at position 2 from the 5′ end of the antisense strand and q⁶is equal to 1, and the modification at the 2′ position or positions in a non-ribose, acyclic or backbone that provide less than or equal to steric bulk than a 2′-OMe ribose.

In one embodiment, Ti is at the cleavage site of the sense strand. In one example, T1 is at position 11 from the 5′ end of the sense strand, when the sense strand is 19-22 nucleotides in length, and n²is 1. In an exemplary embodiment, T1 is at the cleavage site of the sense strand at position 11 from the 5′ end of the sense strand, when the sense strand is 19-22 nucleotides in length, and n²is 1,

In one embodiment, T2′ starts at position 6 from the 5′ end of the antisense strand. In one example, T2′ is at positions 6-10 from the 5′ end of the antisense strand, and q⁴is 1.

In an exemplary embodiment, Ti is at the cleavage site of the sense strand, for instance, at position 11 from the 5′ end of the sense strand, when the sense strand is 19-22 nucleotides in length, and n²is 1; T1′ is at position 14 from the 5′ end of the antisense strand, and q²is equal to 1, and the modification to T1′ is at the 2′ position of a ribose sugar or at positions in a non-ribose, acyclic or backbone that provide less steric bulk than a 2′-OMe ribose; T2′ is at positions 6-10 from the 5′ end of the antisense strand, and q⁴is 1; and T3′ is at position 2 from the 5′ end of the antisense strand, and q⁶is equal to 1, and the modification to T3′ is at the 2′ position or at positions in a non-ribose, acyclic or backbone that provide less than or equal to steric bulk than a 2′-OMe ribose. In one embodiment, T2′ starts at position 8 from the 5′ end of the antisense strand. In one example, T2′ starts at position 8 from the 5′ end of the antisense strand, and q⁴is 2.

In one embodiment, T2′ starts at position 9 from the 5′ end of the antisense strand. In one example, T2′ is at position 9 from the 5′ end of the antisense strand, and q⁴is 1.

In one embodiment, B1′ is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 1, B3′ is 2′-OMe or 2′-F, q⁵is 6, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within positions 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand).

In one embodiment, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 1, B3′ is 2′-OMe or 2′-F, q⁵is 6, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within positions 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand).

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within positions 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand).

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 6, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 7, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 6, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 7, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within positions 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand).

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 1, B3′ is 2′-OMe or 2′-F, q⁵is 6, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within positions 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand).

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 5, T2′ is 2′-F, q⁴is 1, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; optionally with at least 2 additional TT at the 3′-end of the antisense strand; with two phosphorothioate internucleotide linkage modifications within positions 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand).

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1. In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within positions 1-5 of the sense strand (counting from the 5′-end), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end).

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1. In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within positions 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand).

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1. In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within positions 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand).

The RNAi agent can comprise a phosphorus-containing group at the 5′-end of the sense strand or antisense strand. The 5′-end phosphorus-containing group can be 5′-end phosphate (5′-P), 5′-end phosphorothioate (5′-PS), 5′-end phosphorodithioate (5′-PS₂), 5′-end vinylphosphonate (5′-VP), 5′-end methylphosphonate (MePhos), or 5′-deoxy-5′-C-malonyl

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When the 5′-end phosphorus-containing group is 5′-end vinylphosphonate (5′-VP), the 5′-VP can be either 5′-E-VP isomer (i.e., trans-vinylphosphonate,

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5′-Z-VP isomer (i.e., cis-vinylphosphonate,

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or mixtures thereof.

In one embodiment, the RNAi agent comprises a phosphorus-containing group at the 5′-end of the sense strand. In one embodiment, the RNAi agent comprises a phosphorus-containing group at the 5′-end of the antisense strand.

In one embodiment, the RNAi agent comprises a 5′-P. In one embodiment, the RNAi agent comprises a 5′-P in the antisense strand.

In one embodiment, the RNAi agent comprises a 5′-PS. In one embodiment, the RNAi agent comprises a 5′-PS in the antisense strand.

In one embodiment, the RNAi agent comprises a 5′-VP. In one embodiment, the RNAi agent comprises a 5′-VP in the antisense strand. In one embodiment, the RNAi agent comprises a 5′-E-VP in the antisense strand. In one embodiment, the RNAi agent comprises a 5′-Z-VP in the antisense strand.

In one embodiment, the RNAi agent comprises a 5′-PS₂. In one embodiment, the RNAi agent comprises a 5′-PS₂in the antisense strand.

In one embodiment, the RNAi agent comprises a 5′-PS₂. In one embodiment, the RNAi agent comprises a 5′-deoxy-5′-C-malonyl in the antisense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-P.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-PS.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-VP. The 5′-VP may be 5′-E-VP, 5′-Z-VP, or combination thereof.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-PS₂.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-deoxy-5′-C-malonyl.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end). The RNAi agent also comprises a 5′-P.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end). The RNAi agent also comprises a 5′-PS.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end). The RNAi agent also comprises a 5′-VP. The 5′-VP may be 5′-E-VP, 5′-Z-VP, or combination thereof.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end). The RNAi agent also comprises a 5′-PS₂.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end). The RNAi agent also comprises a 5′-deoxy-5′-C-malonyl.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-P.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-PS.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-VP. The 5′-VP may be 5′-E-VP, 5′-Z-VP, or combination thereof.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-PS₂.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-deoxy-5′-C-malonyl.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-P.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-PS.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-VP. The 5′-VP may be 5′-E-VP, 5′-Z-VP, or combination thereof.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-PS₂.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-deoxy-5′-C-malonyl.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-P and a targeting ligand. In one embodiment, the 5′-P is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, B1′ is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-PS and a targeting ligand. In one embodiment, the 5′-PS is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, B1′ is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-VP (e.g., a 5′-E-VP, 5′-Z-VP, or combination thereof), and a targeting ligand.

In one embodiment, the 5′-VP is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, B1′ is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-PS₂and a targeting ligand. In one embodiment, the 5′-PS₂is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, B1′ is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-deoxy-5′-C-malonyl and a targeting ligand. In one embodiment, the 5′-deoxy-5′-C-malonyl is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end). The RNAi agent also comprises a 5′-P and a targeting ligand. In one embodiment, the 5′-P is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end). The RNAi agent also comprises a 5′-PS and a targeting ligand. In one embodiment, the 5′-PS is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end). The RNAi agent also comprises a 5′-VP (e.g., a 5′-E-VP, 5′-Z-VP, or combination thereof) and a targeting ligand. In one embodiment, the 5′-VP is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end). The RNAi agent also comprises a 5′-PS₂and a targeting ligand. In one embodiment, the 5′-PS₂is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-OMe, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end). The RNAi agent also comprises a 5′-deoxy-5′-C-malonyl and a targeting ligand. In one embodiment, the 5′-deoxy-5′-C-malonyl is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-P and a targeting ligand. In one embodiment, the 5′-P is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-PS and a targeting ligand. In one embodiment, the 5′-PS is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-VP (e.g., a 5′-E-VP, 5′-Z-VP, or combination thereof) and a targeting ligand. In one embodiment, the 5′-VP is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, BF is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-PS₂and a targeting ligand. In one embodiment, the 5′-PS₂is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, B1′ is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, T2′ is 2′-F, q⁴is 2, B3′ is 2′-OMe or 2′-F, q⁵is 5, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-deoxy-5′-C-malonyl and a targeting ligand. In one embodiment, the 5′-deoxy-5′-C-malonyl is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, B1′ is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-P and a targeting ligand. In one embodiment, the 5′-P is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, B1′ is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-PS and a targeting ligand. In one embodiment, the 5′-PS is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, B1′ is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-VP (e.g., a 5′-E-VP, 5′-Z-VP, or combination thereof) and a targeting ligand. In one embodiment, the 5′-VP is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, B1′ is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-PS₂and a targeting ligand. In one embodiment, the 5′-PS₂is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In one embodiment, B1 is 2′-OMe or 2′-F, n¹is 8, T1 is 2′F, n²is 3, B2 is 2′-OMe, n³is 7, n⁴is 0, B3 is 2′-OMe, n⁵is 3, B1′ is 2′-OMe or 2′-F, q¹is 9, T1′ is 2′-F, q²is 1, B2′ is 2′-OMe or 2′-F, q³is 4, q⁴is 0, B3′ is 2′-OMe or 2′-F, q⁵is 7, T3′ is 2′-F, q⁶is 1, B4′ is 2′-F, and q⁷is 1; with two phosphorothioate internucleotide linkage modifications within position 1-5 of the sense strand (counting from the 5′-end of the sense strand), and two phosphorothioate internucleotide linkage modifications at positions 1 and 2 and two phosphorothioate internucleotide linkage modifications within positions 18-23 of the antisense strand (counting from the 5′-end of the antisense strand). The RNAi agent also comprises a 5′-deoxy-5′-C-malonyl and a targeting ligand. In one embodiment, the 5′-deoxy-5′-C-malonyl is at the 5′-end of the antisense strand, and the targeting ligand is at the 3′-end of the sense strand.

In a particular embodiment, an RNAi agent of the present invention comprises:

- (a) a sense strand having:
  - (i) a length of 21 nucleotides;
  - (ii) an ASGPR ligand attached to the 3′-end, wherein said ASGPR ligand comprises three GalNAc derivatives attached through a trivalent branched linker; and
  - (iii) 2′-F modifications at positions 1, 3, 5, 7, 9 to 11, 13, 17, 19, and 21, and 2′-OMe modifications at positions 2, 4, 6, 8, 12, 14 to 16, 18, and 20 (counting from the 5′ end);
- and
- (b) an antisense strand having:
  - (i) a length of 23 nucleotides;
  - (ii)2′-OMe modifications at positions 1, 3, 5, 9, 11 to 13, 15, 17, 19, 21, and 23, and 2′F modifications at positions 2, 4, 6 to 8, 10, 14, 16, 18, 20, and 22 (counting from the 5′ end); and
  - (iii) phosphorothioate internucleotide linkages between nucleotide positions 21 and 22, and between nucleotide positions 22 and 23 (counting from the 5′ end);
- wherein the dsRNA agents have a two nucleotide overhang at the 3′-end of the antisense strand, and a blunt end at the 5′-end of the antisense strand.

In another particular embodiment, an RNAi agent of the present invention comprises:

- (a) a sense strand having:
  - (i) a length of 21 nucleotides;
  - (ii) an ASGPR ligand attached to the 3′-end, wherein said ASGPR ligand comprises three GalNAc derivatives attached through a trivalent branched linker;
  - (iii) 2′-F modifications at positions 1, 3, 5, 7, 9 to 11, 13, 15, 17, 19, and 21, and 2′-OMe modifications at positions 2, 4, 6, 8, 12, 14, 16, 18, and 20 (counting from the 5′ end); and
  - (iv) phosphorothioate internucleotide linkages between nucleotide positions 1 and 2, and between nucleotide positions 2 and 3 (counting from the 5′ end);
- and
- (b) an antisense strand having:
  - (i) a length of 23 nucleotides;
  - (ii) 2′-OMe modifications at positions 1, 3, 5, 7, 9, 11 to 13, 15, 17, 19, and 21 to 23, and 2′F modifications at positions 2, 4, 6, 8, 10, 14, 16, 18, and 20 (counting from the 5′ end); and
  - (iii) phosphorothioate internucleotide linkages between nucleotide positions 1 and 2, between nucleotide positions 2 and 3, between nucleotide positions 21 and 22, and between nucleotide positions 22 and 23 (counting from the 5′ end);
    
    wherein the RNAi agents have a two nucleotide overhang at the 3′-end of the antisense strand, and a blunt end at the 5′-end of the antisense strand.