Patent Application
20250186627
The present invention relates to radiolabelled compounds for treatment of diseases or conditions characterized by expression of prostate-specific membrane antigen, particularly compounds with low uptake in salivary glands and/or kidneys.
Prostate-specific membrane antigen (PSMA) is a transmembrane protein that catalyzes the hydrolysis of N-acetyl-aspartylglutamate to glutamate and N-acetylaspartate. PSMA is selectively overexpressed in certain diseases and conditions compared to most normal tissues. For example, PSMA is overexpressed up to 1,000-fold in prostate tumors and metastases. Due to its pathological expression pattern, various radiolabeled PSMA-targeting constructs have been designed and evaluated for imaging of PSMA-expressing tissues and/or for therapy of diseases or conditions characterized by PSMA expression.
A number of radiolabeled PSMA-targeting derivatives of lysine-urea-glutamate (Lys-ureido-Glu) have been developed, including 18F-DCFBC, 18F-DCFPyL, 68Ga-PSMA-HBED-CC, 68Ga-PSMA-617, 68Ga-PSMA I & T (see
In clinical trials, PSMA-617 radiolabeled with therapeutic radionuclides, such as 177Lu and 225Ac, has shown promise as an effective systemic treatment for metastatic castration resistant prostate cancer (mCRPC). However, dry mouth (xerostomia), altered taste and adverse renal events are common side effects of this treatment, due to high salivary gland and kidney accumulation of the radiotracer (Hofman et al., 2018 The Lancet 16(6):825-833; Rathke et al. 2019 Eur J Nucl Med Mol Imaging 46(1):139-147; Sathekge et al. 2019 Eur J Nucl Med Mol Imaging 46(1):129-138). Radiotracer accumulation in the kidneys and salivary gland is therefore a limiting factor that reduces the maximal cumulative administered activity that can be safely given to patients, which limits the potential therapeutic effectiveness of Lys-urea-Glu based radiopharmaceuticals (Violet et al. 2019 J Nucl Med. 60(4):517-523). There is therefore a need for new radiolabeled PSMA-targeting compounds, particularly compounds that have low accumulation in the salivary glands and/or kidneys.
No admission is necessarily intended, nor should it be construed, that any of the preceding information constitutes prior art against the present invention.
This disclosure relates to PSMA-targeting compounds that bind PSMA using a Lys-ureido-Glu moiety or derivative moiety thereof, a radiometal chelator, and an albumin binder. The positions of both the radiometal chelator and the albumin binder relative to the PSMA-binding moiety result in novel compounds with useful delivery of radiation to tumor site(s) and improved side effects (e.g. low uptake in kidneys and/or salivary gland). Without wishing to be bound by theory, the disclosed compounds may minimize structural hinderance.
The features of the invention will become apparent from the following description in which reference is made to the appended drawings wherein:
All publications, patents and patent applications, including any drawings and appendices therein are incorporated by reference in their entirety for all purposes to the same extent as if each individual publication, patent or patent application, drawing, or appendix was specifically and individually indicated to be incorporated by reference in its entirety for all purposes.
As used herein, the terms “comprising,” “having”, “including” and “containing,” and grammatical variations thereof, are inclusive or open-ended and do not exclude additional, unrecited elements and/or method steps, even if a feature/component defined as a part thereof consists or consists essentially of specified feature(s)/component(s). The term “consisting essentially of” if used herein in connection with a compound, composition, use or method, denotes that additional elements and/or method steps may be present, but that these additions do not materially affect the manner in which the recited compound, composition, method or use functions. The term “consisting of” if used herein in connection with a feature of a composition, use or method, excludes the presence of additional elements and/or method steps in that feature. A compound, composition, use or method described herein as comprising certain elements and/or steps may also, in certain embodiments consist essentially of those elements and/or steps, and in other embodiments consist of those elements and/or steps, whether or not these embodiments are specifically referred to. A use or method described herein as comprising certain elements and/or steps may also, in certain embodiments consist essentially of those elements and/or steps, and in other embodiments consist of those elements and/or steps, whether or not these embodiments are specifically referred to.
A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the elements is present, unless the context clearly requires that there be one and only one of the elements. The singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. The use of the word “a” or “an” when used herein in conjunction with the term “comprising” may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one” and “one or more than one.”
In this disclosure, the recitation of numerical ranges by endpoints includes all numbers subsumed within that range including all whole numbers, all integers and, where suitable, all fractional intermediates (e.g., 1 to 5 may include 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5 etc.).
Unless otherwise specified, “certain embodiments”, “various embodiments”, “an embodiment” and similar terms includes the particular feature(s) described for that embodiment either alone or in combination with any other embodiment or embodiments described herein, whether or not the other embodiments are directly or indirectly referenced and regardless of whether the feature or embodiment is described in the context of a method, product, use, composition, compound, etcetera.
As used herein, the terms “treat”, “treatment”, “therapeutic” and the like includes ameliorating symptoms, reducing disease progression, improving prognosis and reducing recurrence.
The term “subject” refers to an animal (e.g. a mammal or a non-mammal animal). The subject may be a human or a non-human primate. The subject may be a laboratory mammal (e.g., mouse, rat, rabbit, hamster and the like). The subject may be an agricultural animal (e.g., equine, ovine, bovine, porcine, camelid and the like) or a domestic animal (e.g., canine, feline and the like). In some embodiments, the subject is a human.
The compounds disclosed herein may also include base-free forms, salts or pharmaceutically acceptable salts thereof. Unless otherwise specified, the compounds claimed and described herein are meant to include all racemic mixtures and all individual enantiomers or combinations thereof, whether or not they are explicitly represented herein.
The compounds disclosed herein may be shown as having one or more charged groups, may be shown with ionizable groups in an uncharged (e.g. protonated) state or may be shown without specifying formal charges. As will be appreciated by the person of skill in the art, the ionization state of certain groups within a compound (e.g. without limitation, CO2H, PO3H2, SO2H, SO3H, SO4H, OPO3H2 and the like) is dependent, inter alia, on the pKa of that group and the pH at that location. For example, but without limitation, a carboxylic acid group (i.e. COOH) would be understood to usually be deprotonated (and negatively charged) at neutral pH and at most physiological pH values, unless the protonated state is stabilized. Likewise, OSO3H (i.e. SO4H) groups, SO2H groups, SO3H groups, OPO3H2 (i.e. PO4H2) groups and PO3H groups would generally be deprotonated (and negatively charged) at neutral and physiological pH values.
As used herein, the terms “salt” and “solvate” have their usual meaning in chemistry. As such, when the compound is a salt or solvate, it is associated with a suitable counter-ion. It is well known in the art how to prepare salts or to exchange counter-ions. Generally, such salts can be prepared by reacting free acid forms of these compounds with a stoichiometric amount of a suitable base (e.g. without limitation, Na, Ca, Mg, or K hydroxide, carbonate, bicarbonate, or the like), or by reacting free base forms of these compounds with a stoichiometric amount of a suitable acid. Such reactions are generally carried out in water or in an organic solvent, or in a mixture of the two. Counter-ions may be changed, for example, by ion-exchange techniques such as ion-exchange chromatography. All zwitterions, salts, solvates and counter-ions are intended, unless a particular form is specifically indicated.
In certain embodiments, the salt or counter-ion may be pharmaceutically acceptable, for administration to a subject. More generally, with respect to any pharmaceutical composition disclosed herein, non-limiting examples of suitable excipients include any suitable buffers, stabilizing agents, salts, antioxidants, complexing agents, tonicity agents, cryoprotectants, lyoprotectants, suspending agents, emulsifying agents, antimicrobial agents, preservatives, chelating agents, binding agents, surfactants, wetting agents, non-aqueous vehicles such as fixed oils, or polymers for sustained or controlled release. See, for example, Berge et al. 1977. (J. Pharm Sci. 66:1-19), or Remington—The Science and Practice of Pharmacy, 21st edition (Gennaro et al editors. Lippincott Williams & Wilkins Philadelphia), each of which is incorporated by reference in its entirety.
As used herein, the expression “Cn” where n is an integer (e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and the like) or where n is defined as a range of integers (e.g. 1-20, 1-18, 2-15, 3-20, and the like) refers to the number of carbons in a compound, R-group, L-group, or substituent, or refers to the number of carbons plus heteroatoms in a compound, R-group, L-group, or substituent. A range of integers includes all integers in the range; e.g. the range 1-20 includes the integers 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20. Unless otherwise defined, heteroatoms may include any, some or all possible heteroatoms. For example, in some embodiments, the heteroatoms may be selected from N, O, S, P and Se. In some embodiments, the heteroatoms are selected from N, S, or O. Such embodiments are non-limiting. The alternative expression “Cy-Cz”, where y and z are integers (e.g. C3-C15 and the like), is equivalent to “Cn” where n is a range of integers from y to z.
The terms “alkyl”, “alkylenyl”, “alkenylenyl”, and “alkynylenyl” have their usual meanings in organic chemistry. For example, an “alkyenylenyl” has at least one carbon-carbon double bond, and may have any number of carbon-carbon single bonds. Similarly, an “alkynylenyl” has at least one carbon-carbon triple bond, and may have any number of carbon-carbon single bonds. The expressions “alkylenyl, alkenylenyl and/or alkynylenyl” and “alkylenyl, alkenylenyl or alkynylenyl” are intended to be equivalent and each includes hydrocarbon chains that can have any reasonable number or combination of carbon-carbon single bonds, double bonds, and triple bonds. These hydrocarbon chains can be linear, branched, cyclic, or any combination of linear and branched, linear and cyclic, cyclic and branched, branched and cyclic, or linear, branched and cyclic. Cyclic hydrocarbons may be nonaromatic, partially aromatic, or aromatic. Unless otherwise specified, the term “cyclic” includes single rings, multiple non-fused rings, fused rings, bridged rings, and combinations thereof.
The expression “wherein any carbon . . . is optionally independently replaced by N, S, or O” and other similar expressions means that the defined hydrocarbon (e.g. “alkyl”, “alkylenyl”, “alkenylenyl”, or “alkynylenyl”) includes zero, one, more than one, or any reasonable combination of two or more heteroatoms selected from N, S, and O. The above expression therefore expands the defined hydrocarbon to additionally encompass heteroalkyls, heteroalkylenyls, heteroalkenylenyls, and heteroalkynylenyls, etc. The person of skill in the art would understand that various combinations of different heteroatoms may be used. The expression “wherein any carbon bonded to two other carbons is optionally independently replaced by N, S, or O” and other similar expressions means that any carbon in the defined hydrocarbon bonded to two other carbons (e.g. the underlined carbon in —C—C—C—), whether those bonds are single, double, or triple bonds, may be a heteroatom, but excludes heteroatoms bonded to other heteroatoms (e.g. excludes —C—N—S—, —S—S—N—, —N—S—C—, and the like).
Various R-groups (e.g. R1, R2, R3, etc.) and L-groups (e.g. L1, L2, L3, etc.) are defined in this disclosure. L-groups generally refer to linkages (e.g. —S—, —NH—C(O)—, —C(O)—NH—, —N(alkyl)-C(O)—, —C(O)—N(alkyl)-, —NH—C(O)—NH—, —NH—C(S)—NH—,
If unspecified, the size of an R-group or L-group is what would be considered reasonable to the person of skill in the art. For example, but without limitation, if unspecified, the size of an alkyl may be 1, 2, 3, 4, 5, 6, 7, 8, 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, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100 or more than 100 carbons in length, subject to the common general knowledge of the person of skill in the art.
Further, but without limitation, if unspecified, the size of a heteroalkyl may be 1, 2, 3, 4, 5, 6, 7, 8, 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, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100 or more than 100 carbons and heteroatoms in length, subject to the common general knowledge of the person of skill in the art. In the context of the expression “alkyl, alkenyl or alkynyl” and similar expressions, the “alkyl” would be understood to be a saturated alkyl, and the “alkenyl” and the “alkynyl” would be understood to be unsaturated.
As used herein, in the context of an alkyl/heteroalkyl group of a compound, the term “linear” may be used as it is normally understood to a person of skill in the art and generally refers to a chemical entity that comprises a skeleton or main chain that does not split off into more than one contiguous chain. Non-limiting examples of linear alkyls include methyl, ethyl, n-propyl, and n-butyl.
As used herein, the term “branched” may be used as it is normally understood to a person of skill in the art and generally refers to a chemical entity that comprises a skeleton or main chain that splits off into more than one contiguous chain. The portions of the skeleton or main chain that split off in more than one direction may be linear, cyclic or any combination thereof. Non-limiting examples of a branched alkyl group include tert-butyl and isopropyl.
The term “alkylenyl” refers to a divalent analog of an alkyl group. In the context of the expression “alkylenyl, alkenylenyl and/or alkynylenyl”, and similar expressions, the “alkylenyl” would be understood to be a saturated alkylenyl, and the “alkenylenyl” and the “alkynylenyl” would be understood to be unsaturated. The term “heteroalkylenyl” refers to a divalent analog of a heteroalkyl group. The term “heteroalkenylenyl” refers to a divalent analog of a heteroalkenyl group.
The term “heteroalkynylenyl” refers to a divalent analog of a heteroalkynyl group.
As used herein, the term “saturated” when referring to a chemical entity may be used as it is normally understood to a person of skill in the art and generally refers to a chemical entity that comprises only single bonds, and may include linear, branched, and/or cyclic groups. Non-limiting examples of a saturated C1-C20 alkyl group may include methyl, ethyl, n-propyl, i-propyl, sec-propyl, n-butyl, i-butyl, sec-butyl, t-butyl, n-pentyl, i-pentyl, sec-pentyl, t-pentyl, n-hexyl, i-hexyl, 1,2-dimethylpropyl, 2-ethylpropyl, 1-methyl-2-ethylpropyl, I-ethyl-2-methylpropyl, 1,1,2-trimethylpropyl, 1,1,2-triethylpropyl, 1,1-dimethylbutyl, 2,2-dimethylbutyl, 2-ethylbutyl, 1,3-dimethylbutyl, 2-methylpentyl, 3-methylpentyl, sec-hexyl, t-hexyl, n-heptyl, i-heptyl, sec-heptyl, t-heptyl, n-octyl, i-octyl, sec-octyl, t-octyl, n-nonyl, i-nonyl, sec-nonyl, t-nonyl, n-decyl, i-decyl, sec-decyl, t-decyl, cyclopropanyl, cyclobutanyl, cyclopentanyl, cyclohexanyl, cycloheptanyl, cyclooctanyl, cyclononanyl, cyclodecanyl, and the like. Unless otherwise specified, a C1-C20 alkylenyl therefore encompasses, without limitation, all divalent analogs of the above-listed saturated alkyl groups.
As used herein, the term “unsaturated” when referring to a chemical entity may be used as it is normally understood to a person of skill in the art and generally refers to a chemical entity that comprises at least one double or triple bond, and may include linear, branched, and/or cyclic groups. Non-limiting examples of a C2-C20 alkenyl group may include vinyl, allyl, isopropenyl, I-propene-2-yl, 1-butene-1-yl, 1-butene-2-yl, 1-butene-3-yl, 2-butene-1-yl, 2-butene-2-yl, octenyl, decenyl, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl, cyclononanenyl, cyclodecanenyl, and the like. Unless otherwise specified, a C1-C20 alkenylenyl therefore encompasses, without limitation, all divalent analogs of the above-listed alkenyl groups. Non-limiting examples of a C2-C20 alkynyl group may include ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl, octynyl, nonynyl, decynyl, and the like. Unless otherwise specified, a C1-C20 alkynylenyl therefore encompasses, without limitation, all divalent analogs of the above-listed alkynyl groups.
Non-limiting examples of non-aromatic cyclic groups include cylcopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like. Non-limiting examples of non-aromatic heterocyclic groups include aziridinyl, azetidinyl, diazetidinyl, pyrrolidinyl, pyrrolinyl, piperidinyl, piperazinyl, imidazolinyl, pyrazolidinyl, imidazolydinyl, phthalimidyl, succinimidyl, oxiranyl, tetrahydropyranyl, oxetanyl, dioxanyl, thietanyl, thiepinyl, morpholinyl, oxathiolanyl, and the like.
Unless further specified, an “aryl” group includes both single aromatic rings as well as fused rings containing at least one aromatic ring. non-limiting examples of C3-C20 aryl groups include phenyl (Ph), pentalenyl, indenyl, naphthyl and azulenyl. Non-limiting examples of aromatic heterocyclic groups of similar size include pyrrolyl, imidazolyl, pyrazolyl, pyridinyl, pyridazinyl, pyrimidinyl, pirazinyl, quinolinyl, isoquinolinyl, acridinyl, indolyl, isoindolyl, indolizinyl, purinyl, carbazolyl, indazolyl, phthalazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, cinnolinyl, pteridinyl, phenanthridinyl, phenazinyl, phenanthrolinyl, perimidinyl, furyl, dibenzofuryl, xanthenyl, benzofuryl, thiophenyl, thianthrenyl, benzothiophenyl, phosphorinyl, phosphinolinyl, phosphindolyl, thiazolyl, oxazolyl, isoxazolyl, and the like.
As used herein, the term “substituted” is used as it would normally be understood to a person of skill in the art and generally refers to a compound or chemical entity that has one chemical group replaced with a different chemical group. Unless otherwise specified, a substituted alkyl, alkylenyl, alkenylenyl, or alkynylenyl has one or more hydrogen atom(s) independently replaced with an atom that is not hydrogen. For example, chloromethyl is a non-limiting example of a substituted alkyl, more particularly an example of a substituted methyl. Aminoethyl is another non-limiting example of a substituted alkyl, more particularly an example of a substituted ethyl. Unless otherwise specified, a substituted compound or group (e.g. R-group or L-group) may be substituted with any chemical group reasonable to the person of skill in the art. For example, but without limitation, a hydrogen bonded to a carbon or heteroatom (e.g. N) may be substituted with halide (e.g. F, I, Br, Cl), amine, amide, oxo, hydroxyl, thiol, phosphate, phosphonate, sulfate, SO2H, SO3H, alkyls, heteroalkyls, aryl, heteroaryl, ketones, carboxaldehyde, carboxylates, carboxamides, nitriles, monohalomethyl, dihalomethyl ortrihalomethyl. In some embodiments, each carbon may be independently substituted or unsubstituted with oxo, hydroxyl, sulfhydryl, amine, amide, urea, halogen, guanidino, carboxylic acid, sulfonic acid, sulfinic acid, or phosphoric acid. In some embodiments, the amide substituent is —C(O)—NH2.
As used herein, the term “unsubstituted” is used as it would normally be understood to a person of skill in the art. Non-limiting examples of unsubstituted alkyls include methyl, ethyl, tert-butyl, pentyl and the like. The expression “optionally substituted” is used interchangeably with the expression “unsubstituted or substituted”. The expression “optionally independently substituted” means that each location may be substituted or may not be substituted, and when substituted each substituent may be the same or different.
In the structures provided herein, hydrogen may or may not be shown. In some embodiments, hydrogens (whether shown or implicit) may be protium (i.e. 1H), deuterium (i.e. 2H) or combinations of 1H and 2H. Methods for exchanging 1H with 2H are well known in the art. For solvent-exchangeable hydrogens, the exchange of 1H with 2H occurs readily in the presence of a suitable deuterium source, without any catalyst. The use of acid, base or metal catalysts, coupled with conditions of increased temperature and pressure, can facilitate the exchange of non-exchangeable hydrogen atoms, generally resulting in the exchange of all 1H to 2H in a molecule.
The compounds disclosed herein may be synthesized (at least in part) using peptide synthesis methods. Each amino acid residue in a peptide or peptidic region has both an amino group and a carboxylic acid group, either or both of which can be used for covalent attachment. In attaching to the remainder of the compound, the amino group and/or the carboxylic acid group may be converted to an amide or other structure; e.g. a carboxylic acid group of a first amino acid is converted to an amide (i.e. a peptide bond) when bonded to the amino group of a second amino acid. As such, amino acid residues may have the formula —N(Ra)—Rb—C(O)—, where Ra and Rb are R-groups. Ra will typically be hydrogen or methyl (or a different alkyl). The amino acid residues of a peptide may comprise typical peptide (amide) bonds and may further comprise bonds between side chain functional groups and the side chain or main chain functional group of another amino acid.
For example, the side chain carboxylate of one amino acid residue (e.g. Asp, Glu, etc.) in the peptide or peptidic region may be bonded to the amine of another amino acid residue (e.g. Dap, Dab, Orn, Lys) in the peptide or peptidic region. Further details are provided below. Unless otherwise indicated, an amino acid may be any amino acid, including proteinogenic and nonproteinogenic amino acids, alpha amino acids, beta amino acids, or any other amino acid. Non-limiting examples of nonproteinogenic amino acids are shown in Table 1 and include: D-amino acids (including without limitation any D-form of the following amino acids), ornithine (Orn), 3-(1-naphtyl)alanine (NaI), 3-(2-naphtyl)alanine (2-NaI), α-aminobutyric acid, norvaline, norleucine (NIe), homonorleucine, beta-(1,2,3-triazol-4-yl)-L-alanine, 1,2,4-triazole-3-alanine, Phe(4-F), Phe(4-Cl), Phe(4-Br), Phe(4-1), Phe(4-NH2), Phe(4-NO2), homoarginine (hArg), 2-amino-4-guanidinobutyric acid (Agb), 2-amino-3-guanidinopropionic acid (Agp), β-alanine, 4-aminobutyric acid, 5-aminovaleric acid, 6-aminohexanoic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid, 10-aminodecanoic acid, 2-aminooctanoic acid, 2-amino-3-(anthracen-2-yl) propanoic acid, 2-amino-3-(anthracen-9-yl)propanoic acid, 2-amino-3-(pyren-1-yl)propanoic acid, Trp(5-Br), Trp(5-OCH3), Trp(6-F), Trp(5-OH) or Trp(CHO), 2-aminoadipic acid (2-Aad), 3-aminoadipic acid (3-Aad), propargylglycine (Pra), homopropargylglycine (Hpg), beta-homopropargylglycine (Bpg), 2,3-diaminopropionic acid (Dap), 2,4-diaminobutyric acid (Dab), azidolysine (Lys(N3)), azido-ornithine (Orn(N3)), 2-amino-4-azidobutanoic acid Dab(N3), Dap(N3), 2-(5′-azidopentyl)alanine, 2-(6′-azidohexyl)alanine, 4-amino-1-carboxymethyl-piperidine (Pip), 4-(2-aminoethyl)-1-carboxymethyl-piperazine (Acp), and tranexamic acid. If not specified as an L- or D-amino acid, an amino acid shall be understood to encompass both L- and D-amino acids.
The wavy line “” symbol shown through or at the end of a bond in a chemical formula (e.g. in the definitions L1, R3, L2, L3 and Ralb of Formula I) is intended to define the group on one side of the wavy line, without modifying the definition of the structure on the opposite side of the wavy line. Where an R-group or L-group is bonded on two or more sides, any atoms shown outside the wavy lines are intended to clarify orientation of the defined group. As such, only the atoms between the two wavy lines constitute the definition of the R-group or L-group. When atoms are not shown outside the wavy lines (e.g. L1), or for a chemical group shown without wavy lines but does have bonds on multiple sides (e.g. —C(O)NH—, and the like), the chemical group should be read from left to right matching the orientation in the formula that the group relates to; e.g. for formula —Ra—Rb—Rc—, the definition of Rb as —C(O)NH— would be incorporated into the formula as —Ra—C(O)NH—R0— not as —Ra—NHC(O)—R0—.
In various aspects, there is disclosed a compound wherein the compound has Formula I (as defined below) or wherein the compound is a salt or a solvate of Formula I:
wherein n11 is 1-4 and R8 is I, Br, F, Cl, H, OH, OCH3, NH2, NO2, or CH3; and
In some embodiments, the compound (of Formula I) has Formula II or is a salt or a solvate of Formula II:
wherein R1, R2, R3, RL3a, R5b, R5c, R6, R7, Rrad, Ralb, L1, L2, L5b, L5c, L6, L7, ring A, n1, n2, n4, and n5 are as defined in Formula I, or as defined in any other embodiment(s) defined herein. In some of these embodiments: R1 is —CH2—CH2— or —CHF—. In some of these embodiments, R2 is —(CH2)4—. In some of these embodiments, L1 is —NH—C(O)—. In some of these embodiments, R3 is
optionally wherein R3 is
In some of these embodiments, L2 is —NHC(O)—. In some of these embodiments, n1 is 0; ring A has 0 double bonds and is bonded at para position, optionally wherein ring A is
In some of these embodiments, n2 is 0 or 1. In some of these embodiments, each RL3a is H. In some of these embodiments, Xbr is N or CH. In some of these embodiments: R5b is —(CH2)4— and R5c is absent; or R5c is —(CH2)4— and R5b is absent. In some of these embodiments, L5b is —NH—C(O)—. In some of these embodiments, L5c is —NH—C(O)—. In some of these embodiments, L5b is —NH—C(O)—. In some of these embodiments, n4 is 0 or 1, and R6—when present—is methylene. In some of these embodiments, n5 is 0 or 1, and R7—when present—is methylene. In some of these embodiments, L6—when present—is —NH—C(O)—. In some of these embodiments, L7—when present—is —NH—C(O)—. In some of these embodiments, Ralb is
wherein n11 is 3 and Ra is OCH3 or NO2. In some of these embodiments, Rrad is DOTA or a DOTA derivative.
In some embodiments, R1 is —R1aR1b—, wherein R1a is absent or —CH2—, and R1b is —CH2— or —CHF;
In another embodiment, R2 is —(CH2)3—, or —(CH2)4—;
In another specific embodiment, L3 is —NHC(O)—. In another specific embodiment, L4 is —NHC(O)—. In another specific embodiment, R4 is methylene. In another specific embodiment, n3 is 1-4. In another specific embodiment, n3 is 1-2. In another specific embodiment, n3 is 1. In another specific embodiment, n2 is 0-1. In another specific embodiment, n2 is 1. In another specific embodiment, R5a is absent. In another specific embodiment, R5a is methylene.
In some embodiments, R1a is absent. In some embodiments, R1a is —CH2—. In some embodiments, R1a is —O—. In some embodiments, R1a is —S—.
In some embodiments, R1b is —CH2—. In some embodiments, R1b is —CHF—.
In some embodiments, R1 is —CH2—. In some embodiments, R1 is —CHF—. In some embodiments, R1 is —CH2—CH2—. In some embodiments, R1 is —CH2—CHF—. In some embodiments, R1 is —O—CH2—. In some embodiments, R1 is —O—CHF—. In some embodiments, R1 is —S—CH2—. In some embodiments, R1 is —S—CHF—.
In some embodiments, R2 is —(CH2)3—O—. In some embodiments, R2 is —(CH2)3—. In some embodiments, R2 is —(CH2)4—. In some embodiments, R2 is —CH2—O—(CH2)2—. In some embodiments, R2 is —CH2—S—(CH2)2—.
In some embodiments, L1 is —N(RL1a)—C(O)— or —C(O)—N(RL1a)— wherein RL1a is as defined in Formula I. In some such embodiments, RL1a is H. In other such embodiments, RL1a is methyl. In other such embodiments, RL1a is ethyl. In yet other such embodiments, RL1a is a benzyl group with 0-4 substituents independently selected from halogen, OMe, or SMe. In yet other such embodiments, RL1a is a benzyl group. In some embodiments, L1 is —N(RL1a)—C(O)— or —(O)—N(RL1a)— wherein L1a is H or methyl. In some embodiments, L1 is —NHC(O)—. In some embodiments, L1 is —C(O)—NH—.
In some embodiment, R5a—Xbr(R5c)—R5b forms a linear or branched C1-C20 alkylenyl, wherein any carbon bonded to two other carbons is optionally independently replaced by 0, wherein carbons are optionally independently substituted with oxo, hydroxyl, amine, amide, or carboxylic acid, wherein one, two, or three of R5a, R5b, and R5c are optionally absent, wherein Xbr is N or CH and wherein Xbr is separated from ring A by at least 4 atoms. In another specific embodiment, the R5a—Xbr(R5c)—R5b forms a linear or branched C1-C10 alkylenyl, wherein any carbon bonded to two other carbons is optionally independently replaced by O. In another specific embodiment, 1, 2, 3 or 4 carbons are replaced by O.
In some embodiments, L1 is —S—. In some embodiments, L1 is —NH—C(O)—NH—. In some embodiments, L1 is —NH—C(S)—NH—. In some embodiments, L1 is
In some embodiments, L1 is
In some embodiments, L1 is
In some embodiments, L1 is
In some embodiments, R3 is:
substituted with 0-4 substituents independently selected from C1-C4 alkyl, halogen, OMe, SMe, NH2, NO2, CN, or OH, and wherein 0-4 ring carbons are replaced with nitrogen; in some such embodiments, the rings are unsubstituted and contain a single nitrogen. In some embodiments, R3 is:
substituted with 0-4 substituents independently selected from C1-C4 alkyl, halogen, OMe, SMe, NH2, NO2, CN, or OH, and wherein 0-4 ring carbons are replaced with nitrogen; in some such embodiments, the rings are unsubstituted and contain a single nitrogen. In some embodiments, R3 is:
In some embodiments, R3 is:
In some embodiments, R3 is:
In some embodiments, R3 is:
In some embodiments, L2 is —N(RL2a)—C(O)— or —C(O)—N(RL2a)— wherein RL2a is as defined in Formula I. In some such embodiments, RL2a is H. In other such embodiments, RL2a is methyl. In other such embodiments, RL2a is ethyl. In yet other such embodiments, RL2a is a benzyl group with 0-4 substituents independently selected from halogen, OMe, or SMe. In yet other such embodiments, RL2a is a benzyl group. In some embodiments, L2 is —N(RL2a)—C(O)— or —(O)—N(RL2a)— wherein L2a is H or methyl. In some embodiments, L2 is —NHC(O)—. In some embodiments, L2 is —C(O)—NH—.
In some embodiments, L2 is —S—. In some embodiments, L2 is —NH—C(O)—NH—. In some embodiments, L2 is —NH—C(S)—NH—. In some embodiments, L2 is
In some embodiments, L2 is
In some embodiments, L2 is
In some embodiments, L2 is
In some embodiments, n1 is 0. In some embodiments, n1 is 1. In some embodiments n1 is 2.
In some embodiments, ring A has 0 double bonds (i.e. all single bonds). In some embodiments, ring A has 1 double bond. In some embodiments, ring A has 2 double bonds. In some embodiments, ring A has 3 double bonds. In some embodiments, ring A is bonded at meta position. In some embodiments, ring A is bonded at para position. In some embodiments, ring A has 0 double bonds and is bonded at para position. In some embodiments, ring A is
In some embodiments, ring A is
In some embodiments, n2 is 0. In some embodiments, n2 is 1. In some embodiments n2 is 2.
In some embodiments, L3 is —N(RL3a)—C(O)— or —C(O)—N(RL3a)— wherein RL3a is as defined in Formula I. In some such embodiments, RL3a is H. In other such embodiments, RL3a is methyl. In other such embodiments, RL3a is ethyl. In some embodiments, L3 is —N(RL3a)—C(O)— or —(O)—N(RL3a)— wherein RL3a is H or methyl. In some embodiments, L3 is —NHC(O)—. In some embodiments, L3 is —C(O)—NH—. In some embodiments, L3 is —S—. In some embodiments, L3 is —NH—C(O)—NH—. In some embodiments, L3 is —NH—C(S)—NH—. In some embodiments, L3 is
In some embodiments, L3 is
In some embodiments, L3 is
In some embodiments, L3 is
In some embodiments, R1 is —CH2—CH2— and R2 is —(CH2)4—. In some such embodiments, L1 is —NH—C(O)—. In some such embodiments, R3 is
optionally wherein R3 is
In some such embodiments, L2 is —NHC(O)—. In some such embodiments, n1 is 0; ring A has 0 double bonds and is bonded at para position, optionally wherein ring A is
In some such embodiments, n2 is 0 or 1. In some such embodiments, L3 is —NHC(O)—.
In some embodiments, n3 is 0. In some embodiments, n3 is 1. In some embodiments n3 is 2. In some embodiments, n3 is 3. In some embodiments n3 is 4.
In embodiments where n3 is not zero, each R4 is independently a linear, branched, and/or cyclic Cn6 alkylenyl, alkenylenyl and/or alkynylenyl, wherein any carbon bonded to two other carbons is optionally independently replaced by N, S, or O, and carbons are optionally independently substituted. In some embodiments, each n6 is independently 1-15 or 1-10. In alternative embodiments, each n6 is independently 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. In some embodiments, each R4 is independently a Cn6 alkylenyl wherein any carbon bonded to two other carbons is optionally independently replaced by N, S, or O, and carbons are optionally independently substituted; in some such embodiments, n3 is 1. In some embodiments, n3 is 1 and R4 is C1-C5 alkylenyl, optionally methylene. In some embodiments, each R4 is independently —C(Raa)H—, wherein each Raa is independently the sidechain of a proteinogenic amino acid or the sidechain of an alpha amino acid from Table 1. In some embodiments, each R4 is independently a proteinogenic amino acid or an amino acid from Table 1 omitting the backbone amino and carboxylic acid groups of the amino acid.
In some embodiments where n3 is not zero, each L4 is independently —N(RL4a)—C(O)— or —C(O)—N(RL4a)— wherein each RL4a is independently H, methyl, or ethyl. In other such embodiments, each RL4a is independently H or methyl. In other such embodiments, at least one RL4a is ethyl. In some embodiments, each L4 is independently —NHC(O)— or —C(O)—NH—. In some embodiments, each L4 is —NHC(O)—. In some embodiments, at least one L4 is —S—. In some embodiments, at least one L4 is —NH—C(O)—NH—. In some embodiments, at least one L4 is —NH—C(S)—NH—. In some embodiments, at least one L4 is
In some embodiments, at least one L4 is
In some embodiments, at least one L4 is
In some embodiments, at least one L4 is
In some embodiments, n3 is 1, R4 is methylene and L4 is —NHC(O)—. In some such embodiments, L3 is —NHC(O)—. In some such embodiments, n2 is 1.
In some embodiments where n3 is not zero, each L4 is independently —N(RL3a)—C(O)— or C(O)—N(RL3a)— wherein each RL3a is independently H, methyl, or ethyl. In other such embodiments, each RL4a is independently H or methyl. In other such embodiments, at least one RL3a is ethyl.
Xbr is a branching atom, i.e. the point where the linker diverges from a single chain to two chains to connect both Rrad and Ralb to the PSMA-binding moiety. In some embodiments, Xbr is N, C or CH. In some embodiments, Xbr is CH. In other embodiments, Xbr is N.
In some embodiments, Xbr is separated from ring A by at least 4 ms, at least 5 atoms, at least 6 atoms, at least 7 atoms, at least 8 atoms, at least 9 atoms, or at least 10 atoms. The expression “Xbr is separated from ring A by at least [number] atoms” refers to the number of atoms that form a contiguous chain by the shortest route between Xbr and ring A, and excluding Xbr and ring A atoms from the atom count. The expression “by the shortest route” in this context refers to the possibility for a ring to be included in the atoms separating Xbr and ring A, such that there are two or more non-equivalent routes to count atoms in a contiguous chain; in such a situation, the shortest route is counted. The number of atoms separating Xbr and ring A does not include hydrogens and does not include any non-hydrogen atoms branching off the shortest route. For example, in the structure CCZ02017 (see Examples for its chemical structure), the number of atoms separating Xbr and ring A is 6, and excludes the two amide oxygens and excludes all hydrogens.
In some embodiments, Xbr is separated from ring A by 6 atoms. In some embodiments, Xbr is separated from ring A by 5 atoms. In some embodiments, Xbr is separated from ring A by 4 atoms.
As defined by Formula I, R5a—Xbr(R5c)—R5b forms a Cn7 alkylenyl, alkenylenyl and/or alkynylenyl, wherein n7 is 1-20 (i.e. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20), wherein any carbon bonded to two other carbons may be independently replaced by N, S, or O heteroatoms. In some embodiments, R5a—Xbr(R5c)—R5b forms a Cn7 alkylenyl. In some embodiments, n7 is 1-15 or 1-10. In some embodiments, 1 carbon is replaced by N, S, or O. In other embodiments, 2, 3, 4, or 5 carbons are each independently replaced by N, S, or O. In some embodiments, the carbons are unsubstituted. In other embodiments, 1 carbon is substituted. In other embodiments, 2 or 3 carbons are independently substituted. The substitutions are as defined in Formula I. In some embodiments, the substitutions are independently selected from one or more than one of hydroxyl, sulfhydryl, amine, guanidino, and/or carboxylic acid. In some embodiments, R5a is absent. In some embodiments, R5b is absent. In some embodiments, R5c is absent. In some embodiments, R5a and R5b are absent. In some embodiments, R5a and R5c are absent. In some embodiments, R5b and R5c are absent. In some embodiments, all three of R5a, R5b, and R5c are absent. In some embodiments, R5a is C1-C6 alkylenyl, optionallly —(CH2)1-4—. In some embodiments, R5b is C1-C6 alkylenyl, optionallly —(CH2)1-4—. In some embodiments, R5c is C1-C6 alkylenyl, optionallly —(CH2)1-4—.
In some embodiments: R5a is absent or C1-C6 alkylenyl, optionally —(CH2)1-4—; R5b is absent or C1-C6 alkylenyl, optionally —(CH2)1-4—; R5c is absent or C1-C6 alkylenyl, optionally —(CH2)1-4—; and Xbr is N, C or CH; wherein any of R5a, R5b or R5c is absent. In some embodiments, R5a—Xbr(R5c)—R5b forms:
wherein each of n12a, n12b, and n12c is independently 0-4. In some embodiments, R5a—Xbr(R5c)—R5b is
In some embodiments, L5b is —N(RL5b)—C(O)— or —C(O)—N(RL5b)— wherein RL5b is H, methyl, or ethyl. In some such embodiments, RL5b is H. In other such embodiments, RL5b is methyl. In other such embodiments, RL5b is ethyl. In some embodiments, L5b is —NHC(O)—. In some embodiments, L5b is —C(O)—NH—. In some embodiments, L5b is —S—.
In some embodiments, L5b is —N(RL3a)—C(O)— or —C(O)—N(RL3a)— wherein RL3a is H, methyl, or ethyl. In some such embodiments, RL3a is H. In other such embodiments, RL3a is methyl. In other such embodiments, RL3a is ethyl. In some embodiments, L5b is —NHC(O)—.
In some embodiments, L5b is —NH—C(O)—NH—. In some embodiments, L5b is —NH—C(S)—NH—. In some embodiments, L5b is
In some embodiments, L5b is
In some embodiments, L5b is
In some embodiments, L5b is
In some embodiments, L5c is —N(RL50)—C(O)— or —C(O)—N(RL50)— wherein RL5c is H, methyl, or ethyl. In other such embodiments, RL5c is methyl. In other such embodiments, RL5c is ethyl. In some embodiments, L5c is —NHC(O)—. In some embodiments, L5c is —C(O)—NH—. In some embodiments, L5c is —S—.
In some embodiments, L5c is —N(RL3a)—C(O)— or —C(O)—N(RL3a)— wherein RL3a is H, methyl, or ethyl. In other such embodiments, RL3a is methyl. In other such embodiments, RL3a is ethyl. In some embodiments, L5c is —NHC(O)—. In some embodiments, L5c is —C(O)—NH—. In some embodiments, L5c is —S—. In some embodiments, L5c is —NH—C(O)—NH—.
In some embodiments, L5c is —NH—C(O)—NH—. In some embodiments, L5c is —NH—C(S)—NH—.
In some embodiments, L5c is
In some embodiments, L5c is
some embodiments, L5c is
In some embodiments, L5c is
In some embodiments: n3 is 0; R5a is methylene; Xbr is N or CH; and R5b is —(CH2)4— and R5c is absent, or R5c is —(CH2)4— and R5b is absent. In some such embodiments, L5b is —NHC(O)—. In some such embodiments, L5c is —NHC(O)—. L5b and L5c may each be —NHC(O)—.
In some embodiments, n4 is 0. In some embodiments, n4 is 1. In some embodiments n4 is 2. In some embodiments, n4 is 3. In some embodiments n4 is 4.
In embodiments where n4 is not zero, each R6 is independently a linear, branched, and/or cyclic Cn8a alkylenyl, alkenylenyl and/or alkynylenyl, wherein each n8a is independently 1-20, wherein any carbon bonded to two other carbons is optionally independently replaced by N, S, or O, and carbons are optionally independently substituted. In some embodiments, each n8a is independently 1-15 or 1-10. In alternative embodiments, each n8a is independently 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. In some embodiments, each R6 is independently a Cn8a alkylenyl wherein any carbon bonded to two other carbons is optionally independently replaced by N, S, or O, and carbons are optionally independently substituted; in some such embodiments, n4 is 1. In some embodiments, n4 is 1 and R6 is C1-C5 alkylenyl, optionally methylene or —(CH2)1-4—. In some embodiments, each R6 is independently —C(Raa)H—, wherein each Raa is independently the sidechain of a proteinogenic amino acid or the sidechain of an alpha amino acid from Table 1. In some embodiments, each R6 is independently a proteinogenic amino acid or an amino acid from Table 1 omitting the backbone amino and carboxylic acid groups of the amino acid.
In some embodiments where n4 is not zero, each L6 is independently —N(RL6a)—C(O)— or C(O)—N(RL6a)— wherein each RL6a is independently H, methyl, or ethyl. In other such embodiments, each RL6a is independently H or methyl. In some embodiments where n4 is not zero, each L6 is independently —N(RL3a)—C(O)— or —C(O)—N(RL3a)— wherein each RL3a is independently H, methyl, or ethyl. In other such embodiments, each RL3a is independently H or methyl. In other such embodiments, at least one RL6a is ethyl. In some embodiments, each L6 is independently-NHC(O)— or —C(O)—NH—. In some embodiments, each L6 is —NHC(O)—. In some embodiments, at least one L6 is —S—. In some embodiments, at least one L6 is —NH—C(O)—NH—. In some embodiments, L6 is —NH—C(S)—NH—. In some embodiments, at least one L6 is
In some embodiments, at least one L6 is
In some embodiments, at least one L6 is
In some embodiments, at least one L6 is
In some embodiments, n5 is 0. In some embodiments, n5 is 1. In some embodiments n5 is 2. In some embodiments, n5 is 3. In some embodiments n5 is 4.
In embodiments where n5 is not zero, each R7 is independently a linear, branched, and/or cyclic Cn8b alkylenyl, alkenylenyl and/or alkynylenyl, wherein each n8b is independently 1-20, wherein any carbon bonded to two other carbons is optionally independently replaced by N, S, or O, and carbons are optionally independently substituted. In some embodiments, each n8b is independently 1-15 or 1-10. In alternative embodiments, each n8b is independently 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. In some embodiments, each R7 is independently a Cn8b alkylenyl wherein any carbon bonded to two other carbons is optionally independently replaced by N, S, or O, and carbons are optionally independently substituted; in some such embodiments, n5 is 1. In some embodiments, n5 is 1 and R7 is C1-C5 alkylenyl, optionally methylene or —(CH2)1-4—. In some embodiments, each R7 is independently —C(Raa)H—, wherein each Raa is independently the sidechain of a proteinogenic amino acid or the sidechain of an alpha amino acid from Table 1. In some embodiments, each R6 is independently a proteinogenic amino acid or an amino acid from Table 1 omitting the backbone amino and carboxylic acid groups of the amino acid.
In some embodiments where n5 is not zero, each L7 is independently —N(RL7a)—C(O)— or C(O)—N(RL7a)— wherein each RL7a is independently H, methyl, or ethyl. In other such embodiments, each RL7a is independently H or methyl. In other such embodiments, at least one RL7a is ethyl. In some embodiments, each L7 is independently —NHC(O)— or —C(O)—NH—. In some embodiments, each L7 is —NHC(O)—. In some embodiments where n5 is not zero, each L7 is independently —N(RL3a)—C(O)— or —C(O)—N(RL3a)— wherein each RL3a is independently H, methyl, or ethyl. In other such embodiments, each RL3a is independently H or methyl. In other such embodiments, at least one RL3a is ethyl. In some embodiments, each L7 is independently —NHC(O)— or —C(O)—NH—. In some embodiments, each L7 is —NHC(O)—. In some embodiments, at least one L7 is —S—. In some embodiments, L7 is —NH—C(O)—NH.
In some embodiments, L7 is —NH—C(S)—NH—. In some embodiments, at least one L7 is
In some embodiments, at least one L7 is
In some embodiments, at least one L7 is
In some embodiments, at least one L7 is
Rrad is a radiometal chelator that is separated from ring A by at least 7 atoms. The expression “Rrad is separated from ring A by at least [number] atoms” refers to the number of atoms that form a contiguous chain by the shortest route between Rrad and ring A, and excluding Rrad and ring A atoms from the atom count. The expression “by the shortest route” in this context refers to the possibility for a ring to be included in the atoms separating Rrad and ring A, such that there are two or more non-equivalent routes to count atoms in a contiguous chain; in such a situation, the shortest route is counted. The number of atoms separating Rrad and ring A does not include hydrogens and does not include any non-hydrogen atoms branching off the shortest route. For example, in the structure CCZ02017 (see Examples for chemical structure), the number of atoms separating Rrad and ring A is 13 (including the linking amide attached to DOTA), and excludes the three amide oxygens, excludes the branch of the linker connecting Ralb, and excludes all hydrogens. In some embodiments, Rrad is separated from ring A by at least 7 atoms, at least 8 atoms, at least 9 atoms, at least 10 atoms, at least 11 atoms, at least 12 atoms, at least 13 atoms, at least 14 atoms, or at least 15 atoms. In some embodiments, Rrad is separated from ring A by 7-18 atoms (e.g. 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 atoms). In some embodiments, Rrad is bound by a radiometal. In some embodiments, the radiometal is not bound to Rrad.
The various embodiments described herein can also be combined to form more specific embodiments as needed. For example, in a specific embodiment, ring A is
In another specific embodiment, R5c is absent; L5c is —N(RL3a)—C(O)— or —C(O)—N(RL3a)—, wherein RL3a is H; R7 is methylene; L7 is —N(RL3a)—C(O)— or —C(O)—N(RL3a)—, wherein RL3a is H;
In another specific embodiment, n2 is 0 or 1; L3 is —N(RL3a)—C(O)—, or —C(O)—N(RL3a)—, wherein RL3a is H; R4 is methylene; L4 is —N(RL3a)—C(O)—, or —C(O)—N(RL3a)—, wherein RL3a is H; n3 is 1; R5a is absent; and Xbr is CH.
In another specific embodiment, R5b is a linear C1-C6 alkylenyl; L5b is —N(RL3a)—, C(O)— or —C(O)—N(RL3a)—, wherein RL3a is H; R6 is methylene; L6 is —N(RL3a)—C(O)— or —O(O)—N(RL3a)—, wherein RL3a is H; and n4 is 0-2.
In some embodiments, Rrad is selected from Table 2, wherein Rrad is optionally bound by a radiometal.
The radiometal chelator may be any radiometal chelator suitable for binding to the radiometal and which is functionalized for attachment to an amino group. Many suitable radiometal chelators are known, e.g. as summarized in Price and Orvig, Chem. Soc. Rev., 2014, 43, 260-290, which is incorporated by reference in its entirety. Non-limiting examples of radiometal chelators include chelators selected from the group consisting of: DOTA and derivatives; DOTAGA; NOTA; NODAGA; NODASA; CB-DO2A; 3p-C-DEPA; TCMC; DO3A; DTPA and DTPA analogues optionally selected from CHX-A″-DTPA and 1B4M-DTPA; TETA; NOPO; Me-3,2-HOPO; CB-TE1A1P; CB-TE2P; MM-TE2A; DM-TE2A; sarcophagine and sarcophagine derivatives optionally selected from SarAr, SarAr-NCS, diamSar, AmBaSar, and BaBaSar; TRAP; AAZTA; DATA and DATA derivatives; H2-macropa or a derivative thereof; H2dedpa, H4octapa, H4py4pa, H4Pypa, H2azapa, H5decapa, and other picolinic acid derivatives; CP256; PCTA; C-NETA; C-NE3TA; HBED; SHBED; BCPA; CP256; YM103; desferrioxamine (DFO) and DFO derivatives; and H6phospa. Exemplary non-limiting examples of radiometal chelators and example radioisotopes chelated by these chelators are shown in Table 2. In Table 2, the functional groups for linkage are shown in their non-linked forms; the person of skill in the art would appreciate that once linked to the compounds disclosed herein, these linking functional groups would be modified (e.g. COOH or NH2 in the chelator would become an amide linkage when reacted with NH2 or COOH, respectively, in the linker). When counting the atoms separating Rrad from ring A, the linkage atoms (or linkage-forming functional groups in Table 2) are not included in the atom count. In alternative embodiments, Rrad comprises a radiometal chelator selected from those listed above or in Table 2 linked via a linkage-forming functional group (e.g. COOH, NH2, SH, and the like). One skilled in the art could replace any of the chelators listed herein with another chelator.
In some embodiments, the chelator is DOTA, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2. In some embodiments, the chelator is CB-DO2A, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is TCMC, or a derivative thereof, linked via an amide (e.g. formed from one of the —CONH2 groups shown in Table 2). In some embodiments, the chelator is 3p-C-DEPA, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is p-NH2-Bn-Oxo-DO3A or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is TETA, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is CB-TE2A, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is Diamsar, or a derivative thereof, linked via an amide (e.g. formed from one of the amino groups shown in Table 2), In some embodiments, the chelator is NOTA, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is NETA, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is HxTSE, or a derivative thereof, linked via an amide (e.g. formed from one of the amino groups shown in Table 2). In some embodiments, the chelator is P2N2Ph2, or a derivative thereof, linked via an amide (e.g. formed from one of the amino groups shown in Table 2). In some embodiments, the chelator is DTPA, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is CHX-A00-DTPA, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is H2dedpa, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is H2azapa, or a derivative thereof, linked via an amdie (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is H4octapa, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is H6phospa, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is H4CHXoctapa, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is H5decapa, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is H4neunpa-p-Bn-NO2, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is SHBED, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is BPCA, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is PCTA, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is H2-MACROPA, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2). In some embodiments, the chelator is Crown, or a derivative thereof, linked via an amide (e.g. formed from one of the carboxyl groups shown in Table 2).
In some embodiments, the radiometal chelator is a derivative of a radiometal chelator shown in Table 2. A derivative may include, e.g. (1) modification of a functional group of the chelator (e.g. a carboxyl group, an amino group, etc.) or (2) attachment of a new functional group (e.g. attachment of an R-group to an ethylene carbon located between two nitrogen atoms, wherein the R-group is a functional group fused to a spacer). In some embodiments, a carboxyl functional group shown in Table 2 is replaced with azidopropyl ethylacetamide (e.g. azido-mono-amide-DOTA), butynylacetamide (e.g. butyne-DOTA), thioethylacetamide (e.g. DO3A-thiol), maleimidoethylacetamide (e.g. maleimido-mono-amide-DOTA), or N-hydroxysuccinimide ester (e.g. DOTA-NHS-ester). When linked, these derivative chelators can be linked either via an amide (formed from a remaining carboxyl group) or via —C(O)—NH—(CH2)2-3-(triazole) or —C(O)—NH—(CH2)2-3-(thiomaleimide). In other embodiments, a backbone carbon (e.g. in an ethylene positioned between two backbone nitrogen atoms) in the chelator ring is fused to an R-group containing a functional group, optionally wherein the R-group is —(CH2)1-3-(phenyl)-N═C═S or —(CH2)1-3-(phenyl)-N═C═O, optionally 1,4-isothiocyanatobenzyl; e.g. p-SCN-Bn-DOTA (S—2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane tetraacetic acid), p-SCN-Bn-NOTA (2-S-(4-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid), and the like. When linked, these derivatives can form a urea linkage (formed from isocyanate) or a thiourea linkage (formed from isothiocyanate).
In some embodiments, the radiometal chelator is conjugated with a radioisotope (i.e. radiometal). The conjugated radioisotope may be, without limitation, 165Er, 212Bi, 166Ho, 149Pm, 159Gd, 105Rh, 109Pd, 198Au, 199Au, 175Yb 142Pr, 177Lu, 111In, 213Bi, 212Pb, 47Sc, 90Y, 225Ac, 117mSn, 153Sm, 149Tb, 161Tb, 224Ra, 227Th, 223Ra, 64Cu, 67Cu, and the like. In some embodiments, the chelator is a chelator from Table 2 and the conjugated radioisotope is a radioisotope indicated in Table 2 as a binder of the particular chelator.
In some embodiments, the chelator is: DOTA or a derivative thereof, optionally conjugated with 177Lu, 111In 213Bi, 212Pb, 47Sc, 90Y, 225Ac, 117mSn, 153Sm, 149Tb, 161Tb, 165Er, 224Ra, 212Bi, 227Th, 223Ra, 64Cu or 67Cu; Crown optionally conjugated with 225Ac, 227Th or 177Lu; 153Sm, MACROPA optionally conjugated with 225Ac; Me-3,2-HOPO optionally conjugated with 227Th; H4py4pa optionally conjugated with 225Ac; H4pypa optionally conjugated with 177Lu; or DTPA optionally conjugated with 111In.
In some embodiments, the chelator is TETA (1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid), SarAr (1-N-(4-Aminobenzyl)-3, 6,10,13,16,19-hexaazabicyclo[6.6.6]-eicosane-1,8-diamine), NOTA (1,4,7-triazacyclononane-1,4,7-triacetic acid), TRAP (1,4,7-triazacyclononane-1,4,7-tris[methyl(2-carboxyethyl)phosphinic acid), HBED (N,N′-bis(2-hydroxybenzyl)-ethylenediamine-N,N′-diacetic acid), 2,3-HOPO (3-hydroxypyridin-2-one), PCTA (3,6,9,15-tetraazabicyclo[9.3.1]-pentadeca-1 (15),11,13-triene-3,6,9,-triacetic acid), DFO (desferrioxamine), DTPA (diethylenetriaminepentaacetic acid), OCTAPA (N,N′-bis(6-carboxy-2-pyridylmethyl)-ethylenediamine-N,N′-diacetic acid) or another picolinic acid derivative.
In some embodiments, the radiometal chelator is mercaptoacetyl, hydrazinonicotinamide, dimercaptosuccinic acid, 1,2-ethylenediylbis-L-cysteine diethyl ester, methylenediphosphonate, hexamethylpropyleneamineoxime, or hexakis(methoxy isobutyl isonitrile). In some of these embodiments, the chelator is bound by a radioisotope. In some such embodiments, the radioisotope is 186Re or 188Re. In some embodiments, the chelator is not bound by a radioisotope.
Ralb is an albumin binder. In some embodiments, Ralb is —(CH2)n9—CH3 wherein n9 is 8-20; in alternative embodiments, n9 is 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. In some embodiments, Ra1b is —(CH2)n10—C(O)OH wherein n10 is 8-20; in alternative embodiments, n10 is 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. In some embodiments, Ralb is
wherein n11 is 1-4 and R8 is I, Br, F, Cl, H, OH, OCH3, NH2, NO2, or CH3; in alternative embodiments, n11 is 1, 2, 3, or 4. In some embodiments, n11 is 3. In some embodiments, R8 is OCH3 or NO2. In some embodiments, Ralb is
Ralb is separated from ring A by at least 7 atoms. In some embodiments, Ralb is separated from ring A by at least 4 atoms, at least 5 atoms, at least 6 atoms, at least 7 atoms, at least 8 atoms, at least 9 atoms, or at least 10 atoms. The expression “Ralb is separated from ring A by at least [number] atoms” refers to the number of atoms that form a contiguous chain by the shortest route between Ralb and ring A, and excluding Ralb and ring A atoms from the atom count. The expression “by the shortest route” in this context refers to the possibility for a ring to be included in the atoms separating Ralb and ring A, such that there are two or more non-equivalent routes to count atoms in a contiguous chain; in such a situation, the shortest route is counted. The number of atoms separating Ralb and ring A does not include hydrogens and does not include any non-hydrogen atoms branching off the shortest route. For example, in the structure CCZ02017 (see Examples for chemical structure), the number of atoms separating Ralb and ring A is 12, and excludes the four amide oxygens, excludes the branch of the linker that links Rrad, and excludes all hydrogens.
In some embodiments, Ralb is separated from ring A by 7-18 atoms, and Rrad is separated from ring A by 7-18 atoms. In some embodiments, Ralb and Rrad are each separated from ring A by 10-11 atoms. In some such embodiments, Xbr is separated from ring A by 4-6, optionally 6 atoms.
In some embodiments, the compound (of Formula I) has Formula II or is a salt or a solvate of Formula II:
wherein R1, R2, R3, RL3a, R5b, R5c, R6, R7, Rrad, Ralb, L1, L2, L5b, L5c, L6, L7, ring A, n1, n2, n4, and n5 are as defined in Formula I, or as defined in any other embodiment(s) defined herein. In some of these embodiments: R1 is —CH2—CH2— or —CHF—. In some of these embodiments, R2 is —(CH2)4—. In some of these embodiments, L1 is —NH—C(O)—. In some of these embodiments, R3 is
optionally wherein R3 is
In some of these embodiments, L2 is —NHC(O)—. In some of these embodiments, n1 is 0; ring A has 0 double bonds and is bonded at para position, optionally wherein ring A is
In some of these embodiments, n2 is 0 or 1. In some of these embodiments, each RL3a is H. In some of these embodiments, Xbr is N, C, or CH. In some of these embodiments: R5b is —(CH2)4— and R5c is absent; or R5c is —(CH2)4— and R5b is absent. In some of these embodiments, L5b is —NH—C(O)—. In some of these embodiments, L5c is —NH—C(O)—. In some of these embodiments, L5b is —NH—C(O)—. In some of these embodiments, n4 is 0 or 1, and R6—when present—is methylene. In some of these embodiments, n5 is 0 or 1, and R7—when present—is methylene. In some of these embodiments, L6-when present—is —NH—C(O)—. In some of these embodiments, L7-when present—is —NH—C(O)—. In some of these embodiments, Ralb is
wherein n11 is 3 and R8 is OCH3 or NO2. In some of these embodiments, Rrad is DOTA or a DOTA derivative.
In some embodiments, the compound is CCZ02009, CCZ02017, CCZ02008, CCZ02025, CCZ02024, CCZ02015, CCZ02019, CCZ02012, or CCZ02013, (see Examples for chemical structures) or a salt or solvate thereof, optionally conjugated with 177Lu, 111In, 213Bi, 212Pb, 47Sc, 90Y, 225Ac, 117mSn, 153Sm, 149Tb, 161Tb, 165Er, 224Ra, 212Bi, 227Th, 223Ra, 64Cu or 67Cu.
In some embodiments, the compound is CCZ02009, CCZ02017, CCZ02008, CCZ02025, CCZ02024, CCZ02015, CCZ02019, CCZ02012, CCZ02005, CCZ02021, CCZ02022, CCZ02059, CCZ02060, CCZ02034, CCZ02061, or CCZ02013, (see Examples for chemical structures) or a salt or solvate thereof, optionally conjugated with 177Lu, 111In, 213Bi, 212Pb, 47Sc, 90Y, 225Ac, 117mSn, 153Sm, 149Tb, 161Tb, 165Er, 224Ra, 212Bi, 227Th, 223Ra, 64Cu or 67Cu.
In some embodiments, the compound is CCZ02005, CCZ02021, CCZ02022, CCZ02059, CCZ02060, CCZ02034, CCZ02061, or a salt or solvate thereof, optionally conjugated with 177Lu, 111In, 213Bi, 212Pb, 47Sc, 90Y, 225Ac, 117mSn, 153Sm, 149Tb, 161Tb, 165Er, 224Ra, 212Bi, 227Th, 223Ra, 64Cu or 67Cu.
When the radiometal chelator is conjugated with a therapeutic radioisotope (e.g. 165Er, 212Bi, 166Ho, 149Pm, 159Gd, 105Rh, 109Pd, 198Au, 199Au, 175Yb, 142Pr, 177Lu, 111In, 213Bi, 212Pb, 47Sc, 90Y, 225Ac, 117mSn, 153Sm, 149Tb, 161Tb, 224Ra, 227Th, 223Ra, 64Cu, 67Cu, or the like), there is disclosed the use of certain embodiments of the compound (or a pharmaceutical composition thereof) for the treatment of PSMA-expressing conditions or diseases (e.g. tumors and the like) in a subject.
Accordingly, there is provided use of the compound in preparation of a medicament for treating a PSMA-expressing condition or disease in a subject. There is also provided a method of treating PSMA-expressing disease in a subject, in which the method comprises: administering to the subject a composition comprising the compound and a pharmaceutically acceptable excipient. For example, but without limitation, the disease may be a PSMA-expressing tumor or a PSMA-expressing cancer.
PSMA expression has been detected in various cancers (e.g. Rowe et al., 2015, Annals of Nuclear Medicine 29:877-882; Sathekge et al., 2015, Eur J Nucl Med Mol Imaging 42:1482-1483; Verburg et al., 2015, Eur J Nucl Med Mol Imaging 42:1622-1623; and Pyka et al., J Nucl Med Nov. 19, 2015 jnumed.115.164442). Accordingly, without limitation, the PSMA-expressing cancer may be prostate cancer, renal cancer, breast cancer, thyroid cancer, gastric cancer, colorectal cancer, bladder cancer, pancreatic cancer, lung cancer, liver cancer, brain tumor, melanoma, neuroendocrine tumor, ovarian cancer or sarcoma. In some embodiments, the cancer is prostate cancer.
The compounds presented herein incorporate peptides, which may be synthesized by any of a variety of methods established in the art. This includes but is not limited to liquid-phase as well as solid-phase peptide synthesis using methods employing 9-fluorenylmethoxycarbonyl (Fmoc) and/or t-butyloxycarbonyl (Boc) chemistries, and/or other synthetic approaches.
Solid-phase peptide synthesis methods and technology are well-established in the art. For example, peptides may be synthesized by sequential incorporation of the amino acid residues of interest one at a time. In such methods, peptide synthesis is typically initiated by attaching the C-terminal amino acid of the peptide of interest to a suitable resin. Prior to this, reactive side chain and alpha amino groups of the amino acids are protected from reaction by suitable protecting groups, allowing only the alpha carboxyl group to react with a functional group such as an amine group, a hydroxyl group, or an alkyl halide group on the solid support. Following coupling of the C-terminal amino acid to the support, the protecting group on the side chain and/or the alpha amino group of the amino acid is selectively removed, allowing the coupling of the next amino acid of interest. This process is repeated until the desired peptide is fully synthesized, at which point the peptide can be cleaved from the support and purified. A non-limiting example of an instrument for solid-phase peptide synthesis is the Aapptec Endeavor 90 peptide synthesizer.
To allow coupling of additional amino acids, Fmoc protecting groups may be removed from the amino acid on the solid support, e.g. under mild basic conditions, such as piperidine (20-50% v/v) in DMF. The amino acid to be added must also have been activated for coupling (e.g. at the alpha carboxylate). Non-limiting examples of activating reagents include without limitation 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HBTU), 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU), 2-(7-Aza-1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HATU), benzotriazole-1-yl-oxy-tris(dimethylamino)phosphoniumhexafluorophosphate (BOP), benzotriazole-1-yl-oxy-tris(pyrrolidino)phosphoniumhexafluorophosphate (PyBOP). Racemization is minimized by using triazoles, such as 1-hydroxy-benzotriazole (HOBt) and 1-hydroxy-7-aza-benzotriazole (HOAt). Coupling may be performed in the presence of a suitable base, such as N,N-diisopropylethylamine (DIPEA/DIEA) and the like. For long peptides or if desired, peptide synthesis and ligation may be used.
Apart from forming typical peptide bonds to elongate a peptide, peptides may be elongated in a branched fashion by attaching to side chain functional groups (e.g. carboxylic acid groups or amino groups), either: side chain to side chain; or side chain to backbone amino or carboxylate. Coupling to amino acid side chains may be performed by any known method, and may be performed on-resin or off-resin. Non-limiting examples include: forming an amide between an amino acid side chain containing a carboxyl group (e.g. Asp, D-Asp, Glu, D-Glu, and the like) and an amino acid side chain containing an amino group (e.g. Lys, D-Lys, Orn, D-Orn, Dab, D-Dab, Dap, D-Dap, and the like) or the peptide N-terminus; forming an amide between an amino acid side chain containing an amino group (e.g. Lys, D-Lys, Orn, D-Orn, Dab, D-Dab, Dap, D-Dap, and the like) and either an amino acid side chain containing a carboxyl group (e.g. Asp, D-Asp, Glu, D-Glu, and the like) or the peptide C-terminus; and forming a 1, 2, 3-triazole via click chemistry between an amino acid side chain containing an azide group (e.g. Lys(N3), D-Lys(N3), and the like) and an alkyne group (e.g. Pra, D-Pra, and the like). The protecting groups on the appropriate functional groups must be selectively removed before amide bond formation, whereas the reaction between an alkyne and an azido groups via the click reaction to form an 1,2,3-triazole does not require selective deprotection. Non-limiting examples of selectively removable protecting groups include 2-phenylisopropyl esters (O-2-PhiPr) (e.g. on Asp/Glu) as well as 4-methyltrityl (Mtt), allyloxycarbonyl (alloc), 1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene))ethyl (Dde), and 1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)-3-methylbutyl (ivDde) (e.g. on Lys/Orn/Dab/Dap). O-2-PhiPr and Mtt protecting groups can be selectively deprotected under mild acidic conditions, such as 2.5% trifluoroacetic acid (TFA) in DCM. Alloc protecting groups can be selectively deprotected using tetrakis(triphenylphosphine)palladium(0) and phenyl silane in DCM. Dde and ivDde protecting groups can be selectively deprotected using 2-5% of hydrazine in DMF. Deprotected side chains of Asp/Glu (L- or D-forms) and Lys/Orn/Dab/Dap (L- or D-forms) can then be coupled, e.g. by using the coupling reaction conditions described above.
Peptide backbone amides may be N-methylated (i.e. alpha amino methylated) or N-alkylated. This may be achieved by directly using Fmoc-N-methylated amino acids (or Fmoc-N-alkylated amino acids) during peptide synthesis. Alternatively, N-methylation (or N-alkylation) under Mitsunobu conditions may be performed. First, a free primary amine group is protected using a solution of 4-nitrobenzenesulfonyl chloride (Ns-Cl) and 2,4,6-trimethylpyridine (collidine) in NMP. N-methylation may then be achieved in the presence of triphenylphosphine, diisopropyl azodicarboxylate (DIAD) and methanol. Subsequently, N-deprotection may be performed using mercaptoethanol and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in NMP. For coupling protected amino acids to N-methylated alpha amino groups, HATU, HOAt and DIEA may be used.
The PSMA-binding moiety (e.g. Lys-ureido-Glu, Lys-ureido-Aad, and the like) may be constructed on solid phase via the formation of a ureido linkage between the amino groups of two amino acids. This can be done by attaching an Fmoc-protecting amino acid (for example Fmoc-Lys(ivDde)-OH) to Wang resin using standard activation/coupling strategy (for example, Fmoc-protected amino acid (4 eq.), HATU (4 eq.) and N,N-diisopropylethylamine (7 eq.) in N,N-dimethylformamide). The Fmoc-protecting group is then removed by 20% piperidine in N,N-dimethylformamide. To form the ureido linkage, the freed amino group of the solid-phase-attached amino acid is reacted with the 2nd amino acid which has its carboxylate group protected with a t-butyl group and its amino group activated and converted to an isocyanate group (—N═C═O). The activation and conversion of an amino group to an isocyanate group can be achieved by reacting the amino group with phosgene or triphosgene. After the formation of the ureido linkage, the side chain functional group of the amino acid (for example ivDde on Lys) can be removed, and then the linker, albumin-binding motif, and/or radiolabeling group (e.g. radiometal chelator and the like) can be subsequently coupled to the PSMA-binding moiety.
The formation of the thioether (—S—) linkages (e.g. for L1, L2, L3, and the like) can be achieved either on solid phase or in solution phase. For example, the formation of thioether (—S—) linkage can be achieved by coupling between a thiol-containing compound (such as the thiol group on cysteine side chain) and an alkyl halide (such as 3-(Fmoc-amino)propyl bromide and the like) in an appropriate solvent (such as N,N-dimethylformamide and the like) in the presence of base (such as N,N-diisopropylethylamine and the like). If the reactions are carried out in solution phase, the reactants used are preferably in equivalent molar ratio (1 to 1), and the desired products can be purified by flash column chromatography or high performance liquid chromatography (HPLC). If the reactions are carried out on solid phase, meaning one reactant has been attached to a solid phase, then the other reactant is normally used in excess amount (3 equivalents of the reactant attached to the solid phase). After the reactions, the excess unreacted reactant and reagents can be removed by sequentially washing the solid phase (resin) using a combination of solvents, such as N,N-dimethylformamide, methanol and dichloromethane, for example.
The formation of the linkage (e.g. for L1, L2, L3, and the like) between a thiol group and a maleimide group can be performed using the conditions described above for the formation of the thioether (—S—) linkage simply by replacing the alkyl halide with a maleimide-containing compounds. Similarly, this reaction can be conducted in solid phase or solution phase. If the reactions are carried out in solution phase, the reactants used are preferably in equivalent molar ratio (1 to 1), and the desired products can be purified by flash column chromatography or high performance liquid chromatography (HPLC). If the reactions are carried out on solid phase, meaning one reactant has been attached to a solid phase, then the other reactant is normally used in excess amount (3 equivalents of the reactant attached to the solid phase). After the reactions, the excess unreacted reactant and reagents can be removed by sequentially washing the solid phase (resin) using a combination of solvents, such as N,N-dimethylformamide, methanol and dichloromethane, for example.
Urea or thiourea linkages can be made from reaction of an amine group with an isocyanate or an isothiocyanate, respectively, which are common functional groups on radiometal chelators. The isothiocyanate functional group may be added to the radiometal chelator by reacting an amino group on the chelator with thiophosgene [i.e. C(S)Cl2]. Similarly, the isocyanate functional group may be added to the radiometal chelator by reacting an amino group on the chelator with phosgene [i.e. C(O)Cl2].
Non-peptide moieties (e.g. radiometal chelator groups, albumin-binding groups and/or linkers) may be coupled to the peptide N-terminus while the peptide is attached to the solid support. This is facile when the non-peptide moiety comprises an activated carboxylate (and protected groups if necessary) so that coupling can be performed on resin. For example, but without limitation, a bifunctional chelator, such as 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) tris(tert-butyl ester) may be activated in the presence of N-hydroxysuccinimide (NHS) and N,N′-dicyclohexylcarbodiimide (DCC) for coupling to a peptide. Alternatively, a non-peptide moiety may be incorporated into the compound via a copper-catalyzed click reaction under either liquid or solid phase conditions. Copper-catalyzed click reactions are well established in the art. For example, 2-azidoacetic acid is first activated by NHS and DCC and coupled to a peptide. Then, an alkyne-containing non-peptide moiety may be clicked to the azide-containing peptide in the presence of Cu2+ and sodium ascorbate in water and organic solvent, such as acetonitrile (ACN) and DMF and the like. Non-peptide moieties may also be added in solution phase, which is routinely performed.
The synthesis of radiometal chelators is well-known and many chelators are commercially available (e.g. from Sigma-Aldrich™/Milipore Sigma™ and others). Protocols for conjugation of radiometals to the chelators are also well known (e.g. see Examples, below).
When the peptide has been fully synthesized on the solid support, the desired peptide may be cleaved from the solid support using suitable reagents, such as TFA, triisopropylsilane (TIS) and water. Side chain protecting groups, such as Boc, pentamethyldihydrobenzofuran-5-sulfonyl (Pbf), trityl (Trt) and tert-butyl (tBu) are simultaneously removed (i.e. deprotection). The crude peptide may be precipitated and collected from the solution by adding cold ether followed by centrifugation. Purification and characterization of the peptides may be performed by standard separation techniques, such as high performance liquid chromatography (HPLC) based on the size, charge and polarity of the peptides. The identity of the purified peptides may be confirmed by mass spectrometry or other similar approaches.
The present invention will be further illustrated in the following examples.
All chemicals and solvents were obtained from commercial sources, and used without further purification. PSMA-targeted peptides were synthesized using solid phase approach on an AAPPTec (Louisville, KY) Endeavor 90 peptide synthesizer. Purification and quality control of cold and radiolabeled peptides were performed on Agilent HPLC systems equipped with a model 1200 quaternary pump, a model 1200 UV absorbance detector (set at 220 nm), and a Bioscan (Washington, DC) NaI scintillation detector. The operation of Agilent HPLC systems was controlled using the Agilent ChemStation software. The HPLC columns used were a semi-preparative column (Luna C18, 5μ, 250×10 mm) and an analytical column (Luna C18, 5μ, 250×4.6 mm) purchased from Phenomenex (Torrance, CA). The HPLC solvents were A: H2O containing 0.1% TFA, and B: CH3CN containing 0.1% TFA. The collected HPLC eluates containing the desired peptide were lyophilized using a Labconco (Kansas City, MO) FreeZone 4.5 Plus freeze-drier. Mass analyses were performed using a Waters (Milford, Massachusetts) LC-MS with a QDa mass detector an ESI ion source. C18 Sep-Pak cartridges (1 cm3, 50 mg) were obtained from Waters (Milford, MA). 68Ga was eluted from an iThemba Labs (Somerset West, South Africa) generator, and was purified using a DGA resin column from Eichrom Technologies LLC (Lisle, IL). Radioactivity of 68Ga or 177Lu-labeled peptides was measured using a Capintec (Ramsey, NJ) CRC©-25R/W dose calibrator, and the radioactivity of mouse tissues collected from biodistribution studies were counted using a Perkin Elmer (Waltham, MA) Wizard2 2480 automatic gamma counter.
Peptidomimetic PSMA-targeting Lys-ureido-Glu moiety was synthesized by solid-phase peptide chemistry. Fmoc-Lys(ivDde)-Wang resin was swelled in CH2Cl2, followed by Fmoc removal by treating the resin with 20% piperidine in DMF. To generate the isocyanate of the H-Glu(OtBu)-OtBu moiety, a solution of H-Glu(OtBu)-OtBu and diisopropylethylamine in CH2Cl2 was cooled to −78° C. in a dry ice/acetone bath. Triphosgene was dissolved in CH2Cl2, and the resulting solution was added dropwise to the reaction at −78° C. The reaction was then allowed to warm to room temperature and stirred for 30 minutes. After which the isocyanate of the H-Glu(OtBu)-OtBu solution was added to the lysine-immobilized resin and reacted for 16 h. After washing the resin with DMF, the ivDde-protecting group was removed with 2% hydrazine in DMF. Fmoc-protected amino acids were then coupled to the side chain of Lys in presence of HATU and N,N-diisopropylethylamine. Finally, DOTA-tris(t-bu)ester (2-(4,7,10-tris(2-(t-butoxy)-2-oxoehtyl)-1,4,7,10)-tetraazacyclododecan-1-yl)acetic acid) was coupled. The peptide was then deprotected and simultaneously cleaved from the resin by treating with 95/5 trifluoroacetic acid (TFA)/triisopropylsilane (TIS) for 3-4 h at room temperature. After filtration, the peptide was precipitated by the addition of the TFA solution to cold diethyl ether. The crude peptide was purified by HPLC using the preparative column. The eluates containing the desired peptide were collected, pooled, and lyophilized.
To prepare Ga or Lu-labeled standards, a solution of each precursor was incubated with GaCl3 or LuCl3 (5 eq.) in NaOAc buffer (0.1 M, 500 μL, pH 4.2) at 80-90° C. for 15 min. The reaction mixture was then purified by HPLC using the semi-preparative column, and the HPLC eluates containing the desired peptide were collected, pooled, and lyophilized.
68Ga, 177Lu and 225Ac Radiolabeling
68Ga was eluted from a 68Ge-generator with 5 mL of 0.05M HCl, collected into 2.5 mL of 12M HCl and trapped onto a DGA resin. The resin was then washed with 3 mL of 5M HCl and the purified [68Ga]3+ was eluted. 177Lu and 225Ac were purchased from ITM (Germany). 68Ga, 177Lu or 225Ac was added to 700 μL of 2M HEPES buffer containing 15-25 nmol of peptide. The reaction mixtures were then either heated at 85-90° C. for 15-30 min or microwaved for 1 min. For 68Ga and 177Lu labeling, each solution was purified by semi-prep HPLC followed by C18 Sep-pak purification. A radiochemical purity of >95%, determined by analytical HPLC, was required for animal studies. For 225Ac labeling, only Sep-pak purification was performed. A radiochemical purity of >95%, determined by radio-TLC, was required for animal studies.
LNCaP cell line was obtained from ATCC (LNCaP clone FGC, CRL-1740). It was established from a metastatic site of left supraclavicular lymph node of human prostatic adenocarcinoma. Cells were cultured in PRMI 1640 medium supplemented with 10% FBS, penicillin (100 U/mL) and streptomycin (100 μg/mL) at 37° C. in a humidified incubator containing 5% CO2. Cells grown to 80-90% confluence were then washed with sterile phosphate-buffered saline (1×PBS pH 7.4) and trypsinization. The collected cells number was counted with a Hausser Scientific (Horsham, PA) Hemacytometer. Approximately 10 million LNCaP cells were inoculated into the left dorsal flank of immunocomprised NRG mice. The tumours were allowed to grow for 4-6 weeks and used for imaging and biodistribution studies when a volume of 200-600 mm3 was reached.
Inhibition constants (Ki) to PSMA were measured by in vitro competition binding assays using [18F]DCFPyL as the radioligand. LNCaP cells which were plated onto a 24-well poly-D-lysine coated plate for 48 h (400,000/well). Growth medium was removed and replaced with HEPES buffered saline (50 mM HEPES, pH 7.5, 0.9% sodium chloride). After 1 h, [18F]DCFPyL (0.1 nM) was added to each well (in triplicate) containing varied concentrations (0.5 mM-0.05 nM) of tested compounds The assay mixtures were incubated for 1 h at 37° C. with gentle agitation followed by two washes with cold HEPES buffered saline. A trypsin solution (0.25%, 400 μL) was then added to each well to harvest the cells. Radioactivity was measured by gamma counting and Ki values calculated using the ‘one site—fit Ki’ built-in model in Prism 8 (GraphPad).
Human serum albumin binding assay was performed using Transil HSA binding kit (Sovicell) according to manufacturer's recommended procedures.
PET imaging experiments were conducted using Siemens Inveon micro PET/CT scanner. SPECT imaging experiments were conducted using an MILabs micro SPECT/CT scanner. Each tumor bearing mouse was injected 4-6 MBq of 68Ga or 18.5 MBq of 177Lu labeled tracer through the tail vein under anesthesia (2% isoflurane in oxygen). The mice were allowed to recover and roam freely in their cage. At pre-defined time point, the mice were sedated again with 2% isoflurane in oxygen inhalation and positioned in the scanner. A 10-min CT scan was conducted first for localization and attenuation correction after segmentation for reconstructing the PET or SPECT images. Then, a 10-min static PET imaging or a one hour (30 min×2 frames) of static SPECT scan was performed to determined uptake in tumor and other organs. The mice were kept warm by a heating pad during acquisition.
For biodistribution studies, the mice were injected with the radiotracer as described above. The mice were anesthetized with 2% isoflurane inhalation, and euthanized by CO2 inhalation. Blood was withdrawn immediately from the heart, and the organs/tissues of interest were collected. The collected organs/tissues were weighed and counted using a Perkin Elmer (Waltham, MA) Wizard2 2480 gamma counter. The uptake in each organ/tissue was normalized to the injected dose (radioactivity) using a standard curve, and expressed as the percentage of the injected dose per gram of tissue (% ID/g).
The chemical structure of CCZ02009 is below:
The synthesis of CCZ02009 follows the general synthesis procedures as described above except that CCZ02009 is based on the Lys-ureido-Aad moiety. To generate the isocyanate of the 2-aminoadipyl moiety, a solution of L-2-aminoadipic acid (Aad) di-tertbutyl ester hydrochloride and diisopropylethylamine in CH2Cl2 was cooled to −78° C. in a dry ice/acetone bath. Triphosgene was dissolved in CH2Cl2, and the resulting solution was added dropwise to the reaction at −78° C. The reaction was then allowed to warm to room temperature and stirred for 30 minutes to give a solution of the isocyanate of the 2-aminoadipyl moiety. Following the urea formation and ivDde deprotection on the Lys side chain, Fmoc-Ala(9-anth)-OH, Fmoc-Tranexamic acid, Fmoc-Gly-OH, Fmoc-Lys(ivDde)-OH, Fmoc-Gly-OH and 4-(p-methoxyphenyl)butyric acid were coupled sequentially. Subsequently, the ivDde group was deprotected and finally DOTA-tris(t-bu)ester was coupled. CCZ02009 was then purified by HPLC. Mass calculated [M+2H]2+=762.9, found 763.0.
The chemical structure of HTK03170 is shown below:
As a comparison, HTK03170 was synthesized, which lacks a glycine spacer between the PSMA and albumin binding moieties shown in CCZ02009. Mass calculated [M+2H]2+=734.4, found 734.7.
Table 3 shows that with a Gly spacer between the PSMA and albumin binding moieties, PSMA binding affinity increased from 1.53±0.33 to 0.12±0.02 nM, and albumin binding affinity increased from 70.1±3.2 to 64.9±2.2 μM.
68Ga-CCZ02009
The chemical structures of CCZ02060 and CCZ02059 are shown below:
The synthesis of CCZ02060 and CCZ02059 follows the synthesis procedures of CCZ02009 as described above, except that CCZ02060 contains two Gly spacers and CCZ02059 contains four Gly spacers. For CCZ02060, mass calculated [M+2H]2+=791.4, found 791.5. For CCZ02059, mass calculated [M+2H]2+=848.4, found 848.5.
CCZ02060 and CCZ02059 binds to PSMA with affinities (Ki) of 1.09±0.19 nM and 10.84±3.28 nM (n=2), respectively.
The chemical structure of CCZ02017 is shown below:
The synthesis of CCZ02017 follows the synthesis procedures of CCZ02009 as described above, except for the albumin binder, which is 4-(p-nitrophenyl)butyric acid in CCZ02017. The 4-(p-nitrophenyl)butyric acid is substantially weaker than 4-(p-methoxyphenyl)butyric acid (Ref. Kuo et al. J Nucl Med. 2021 April; 62(4):521-527).
177Lu-CCZ02017 at 3, 24, 72, 144 and 240 h p.i. Values are in % ID/g.
177Lu-
177Lu-HTK03170
225Ac-CCZ02017 at 3, 24, 72, 144 and 240 h p.i. Values are in % ID/g.
225Ac-CCZ02017
The chemical structure of CCZ02008 is shown below:
The synthesis of CCZ02008 follows the synthesis procedures of CCZ02009 as described above, and instead of Aad, it incorporates 4R-F-Glu. Mass calculated [M+2H]2+=764.9, found 765.2. CCZ02008 binds to PSMA with high affinity Ki=0.48±0.1 nM (n=3). See
177Lu-
The chemical structure of CCZ02025 is shown below:
The synthesis of CCZ02025 follows the synthesis procedures of CCZ02009 as described above, instead of Aad, it incorporates 4R-F-Glu, and instead of 4-(p-methoxyphenyl)butyric acid, it incorporates 4-(p-nitrophenyl)butyric acid. Mass calculated [M+2H]2+=772.4, found 772.6. CCZ02025 binds to PSMA with high affinity Ki=0.59 nM (
68Ga-CCZ02025
The synthesis of CCZ02024 follows the synthesis procedures of CCZ02025 as described above, instead of 4R-F-Glu, it incorporates Glu. Mass calculated [M+2H]2+=763.4, found 763.8. CCZ02024 binds to PSMA with high affinity Ki=1.54 nM (
The chemical structure of CCZ02015 is shown below:
The synthesis of CCZ02015 follows the synthesis procedures of CCZ02009 as described above. The differences are that CCZ02015 does not contain the Gly spacer and incorporate an elongated linker, i.e. beta-homoLys instead of Lys. Mass calculated [M+2H]2+=741.4, found 741.5. CCZ02015 binds to PSMA with high affinity Ki=1.09±0.30 nM (
68Ga-CCZ02015
The chemical structure of CCZ02019 is shown below:
The synthesis of CCZ02019 follows the synthesis procedures of CCZ02015 as described above. The difference is that CCZ02019 incorporates 4R-F-Glu instead of Aad in the PSMA binding motif. Mass calculated [M+2H]2+=743.4, found 743.7. 177Lu-CCZ02019 shows good tumor uptake and overall background tissue clearance (Table 11).
177Lu-CCZ02019 at 3, 24, 72, 144 and 240 h p.i. Values are in % ID/g.
177Lu-CCZ02019
The chemical structure of CCZ02012 (left) and CCZ02013 (right) are shown below:
The synthesis of CCZ02012 and CCZ02013 follows the general synthesis procedures as described above on the Lys-ureido-Aad backbone, and instead of Fmoc-Tranexamic acid, Fmoc-trans-4-aminocyclohexane carboxylic acid (ACHC) and Fmoc-cis-4-ACHC were incorporated, respectively. For CCZ02012, mass calculated [M+2H]2+=546.8, found 547.1. For CCZ02013, mass calculated [M+2H]2+=546.8, found 547.2. The use of ACHC, either trans or cis, did not affect the binding to PSMA substantially. CCZ02012 and CCZ02013 bind to PSMA at Ki=1.67 nM (n=1) and Ki=1.53±0.21 nM (n=2), respectively.
The chemical structures of CCZ02021 and CCZ02022 are shown below:
The synthesis of CCZ02021 and CCZ02022 follows the synthesis procedures of CCZ02012 as described with CCZ02021 incorporating a Gly spacer, and CCZ02022 incorporating a Gly spacer and beta-homoLys instead of Lys. For CCZ02021, mass calculated [M+2H]2+=763.4, found 763.5. For CCZ02022, mass calculated [M+2H]2+=770.4, found 770.7. CCZ02021 and CCZ02022 bind to PSMA at Ki=5.71 nM (n=1) and Ki=11.2 nM (n=1), respectively.
The chemical structure of CCZ02034 is shown below:
The synthesis of CCZ02034 follows the synthesis procedures of CCZ02017 as described with CCZ02034 incorporating a crown chelator instead of DOTA. Mass calculated [M+2H]2+=814.4, found 814.6. CCZ02034 binds to PSMA at Ki=2.82 nM (n=1). See
The chemical structure of CCZ02005 is shown below:
The synthesis of CCZ02005 follows the general procedures as described above with a PEG2 spacer incorporated between the albumin binding group and the DOTA chelator. Mass calculated [M+2H]2+=806.9, found 807.0. CCZ02005 binds to PSMA at Ki=2.08 nM (n=1). See
The chemical structure of CCZ02061 is shown below:
The synthesis of CCZ02061 follows the synthesis procedures of CCZ02017 described above with addition of a Gly spacer incorporated between the albumin binding group and the DOTA chelator. Mass calculated [M+2H]2+=798.9, found 798.9. CCZ02017 binds to PSMA at Ki=1.14±0.37 nM (n=2). See
This application claims priority to U.S. Provisional Application No. 63/316,595, filed Mar. 4, 2022, the disclosure of which is herein incorporated by reference in its entirety for all purposes.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CA2023/050280 | 3/3/2023 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63316595 | Mar 2022 | US |
