Bicyclic peptide ligands and uses thereof

TECHNICAL FIELD OF THE INVENTION

The present invention relates to polypeptides which are covalently bound to molecular scaffolds such that two or more peptide loops are subtended between attachment points to the scaffold. In particular, the invention describes scaffolds that are useful for the organization and presentation of the subtended peptide loops. The invention also describes peptides which are high affinity binders of carbonic anhydrase IX (CAIX) or membrane type 1 metalloprotease (MT1-MMP). The invention also includes pharmaceutical compositions comprising said peptide ligands and to the use of said peptide ligands in preventing, suppressing or treating a disease or disorder mediated by CAIX or MT1-MMP.

The invention also describes peptides which are high affinity binders of CD38 (cluster of differentiation 38), also known as cyclic ADP ribose hydrolase is a glycoprotein found on the surface of many immune cells (white blood cells), including CD4⁺, CD8⁺, B lymphocytes and natural killer cells. CD38 also functions in cell adhesion, signal transduction and calcium signaling. The invention also describes peptides which are high affinity binders of EphA2 (ephrin type-A receptor 2) and PBP1A (penicillin-binding protein 1A). The invention also includes pharmaceutical compositions comprising said peptide ligands and to the use of said peptide ligands in preventing, suppressing or treating a disease or disorder mediated by CD38, EphA2, or PBP1A.

BACKGROUND OF THE INVENTION

Cyclic peptides are able to bind with high affinity and target specificity to protein targets and hence are an attractive molecule class for the development of therapeutics. In fact, several cyclic peptides are already successfully used in the clinic, as for example the antibacterial peptide vancomycin, the immunosuppressant drug cyclosporine or the anti-cancer drug octreotide (Driggers et al. (2008), Nat Rev Drug Discov 7 (7), 608-24). Good binding properties result from a relatively large interaction surface formed between the peptide and the target as well as the reduced conformational flexibility of the cyclic structures. Typically, macrocycles bind to surfaces of several hundred square angstrom, as for example the cyclic peptide CXCR4 antagonist CVX15 (400 A2; Wu et al. (2007), Science 330, 1066-71), a cyclic peptide with the Arg-Gly-Asp motif binding to integrin αVb3 (355 Å2) (Xiong et al. (2002), Science 296 (5565), 151-5) or the cyclic peptide inhibitor upain-1 binding to urokinase-type plasminogen activator (603 Å2; Zhao et al. (2007), J Struct Biol 160 (1), 1-10).

Due to their cyclic configuration, peptide macrocycles are less flexible than linear peptides, leading to a smaller loss of entropy upon binding to targets and resulting in a higher binding affinity. The reduced flexibility also leads to locking target-specific conformations, increasing binding specificity compared to linear peptides. This effect has been exemplified by a potent and selective inhibitor of matrix metalloproteinase 8, MMP-8) which lost its selectivity over other MMPs when its ring was opened (Cherney et al. (1998), J Med Chem 41 (11), 1749-51). The favorable binding properties achieved through macrocyclization are even more pronounced in multicyclic peptides having more than one peptide ring as for example in vancomycin, nisin and actinomycin.

Different research teams have previously tethered polypeptides with cysteine residues to a synthetic molecular structure (Kemp and McNamara (1985), J. Org. Chem; Timmerman et al. (2005), ChemBioChem). Meloen and co-workers had used tris(bromomethyl)benzene and related molecules for rapid and quantitative cyclization of multiple peptide loops onto synthetic scaffolds for structural mimicry of protein surfaces (Timmerman et al. (2005), ChemBioChem). Methods for the generation of candidate drug compounds wherein said compounds are generated by linking cysteine containing polypeptides to a molecular scaffold as for example tris(bromomethyl)benzene are disclosed in WO 2004/077062 and WO 2006/078161.

Phage display-based combinatorial approaches have been developed to generate and screen large libraries of bicyclic peptides to targets of interest (Heinis et al. (2009), Nat Chem Biol 5 (7), 502-7 and WO2009/098450). Briefly, combinatorial libraries of linear peptides containing three cysteine residues and two regions of six random amino acids (Cys-(Xaa)6-Cys-(Xaa)6-Cys) were displayed on phage and cyclised by covalently linking the cysteine side chains to a small molecule (tris-(bromomethyl)benzene).

Such bicyclic constrained peptide binders (Bicycles) have proven to be especially effective binders for a variety of biological targets. As a result, there is a need to expand the scope of molecular scaffolds from the relatively planar tris-(bromomethyl)benzene to molecular scaffolds that possess a higher sp³content. The addition of sp³content which is defined as Fsp³, where Fsp³=(sp³hybridized carbons/total carbon count), in small molecules has been associated with higher success rates in clinical development due to improved physicochemical properties such as solubility (Lovering et al. (2009), J. Med. Chem. 52(21), 6752-6756; Lovering (2013), Med. Chem. Commun., 4, 515-519). Without being bound by any particular theory, it is believed that access to a larger variety of molecular scaffolds could potentially provide differential displays of the same amino acid sequence that may prove beneficial in increasing selectivity in addition to improving physicochemical properties. Therefore, there exists a need to develop a greater variety of molecular scaffolds for the preparation of bicyclic constrained peptide binders.

SUMMARY OF THE INVENTION

It has now been found that compounds of this invention, and pharmaceutically acceptable compositions thereof, are effective as inhibitors of CAIX, MT1-MMP, CD38, EphA2, or PBP1A. In certain embodiments, a compound of the invention is of formula I:

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or a pharmaceutically acceptable salt thereof, wherein each variable is as defined and described herein. In certain embodiments, a compound of the invention is of formula II:

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or a pharmaceutically acceptable salt thereof, wherein each variable is as defined and described herein.

Compounds of the present invention, and pharmaceutically acceptable compositions thereof, are useful for treating a variety of diseases, disorders or conditions, associated with CAIX, MT1-MMP, CD38, EphA2, or PBP1A. Such diseases, disorders, or conditions include those described herein.

Compounds provided by this invention are also useful for the study of CAIX, MT1-MMP, CD38, EphA2, or PBP1A enzymes in biological and pathological phenomena; the study of these enzymes occurring in bodily tissues; and the comparative evaluation of new CAIX, MT1-MMP, CD38, EphA2, or PBP1A inhibitors in vitro or in vivo.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS
1. General Description of Certain Embodiments of the Invention

In some embodiments, peptide sequences are treated with molecular scaffold reagents to form compounds of the present invention.

Compounds of the present invention, and compositions thereof, are useful as inhibitors of CAIX, MT1-MMP, CD38, EphA2, or PBP1A. In some embodiments, a provided compound inhibits CAIX. In some embodiments, a provided compound inhibits MT1-MMP. In some embodiments, a provided compound inhibits CD38. In some embodiments, a provided compound inhibits EphA2. In some embodiments, a provided compound inhibits PBP1A.

In certain embodiments, the present invention provides a compound of formula I:

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or a pharmaceutically acceptable salt thereof, wherein:

each of L¹, L², and L³is independently a covalent bond or a C_1-8bivalent hydrocarbon chain wherein one, two or three methylene units of the chain are optionally and independen-tly replaced by -Cy¹-, —S—, —N(R)—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —C(O)N(R)—, —N(R)C(O)—, —OC(O)N(R)—, —N(R)C(O)O—, —S(O)—, —S(O)₂—, —C(CH₃)═N—N(R)—, —N(R)N═C(CH₃)—, —N(R)CH₂C(O)—, —(CH₂CH₂O)_1-10—,

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L⁴is a covalent bond, —O—, —N(R)—, or —N(R)CH₂CH₂N(R)—;

each R is independently hydrogen or C_1-4aliphatic;

each -Cy¹- is independently an optionally substituted bivalent ring selected from phenylene, 3-7 membered saturated or partially unsaturated carbocyclylene, 4-7 membered saturated or partially unsaturated heterocyclylene having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered saturated or partially unsaturated bicyclic heterocyclylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered saturated or partially unsaturated tricyclic heterocyclylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered partially saturated bicyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered partially saturated tricyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 9-12 membered bicyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 19-20 membered partially unsaturated tetracyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or 5-6 membered heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;

Scaffold is a trivalent group that connects and orients a cyclic peptide;

Loop A is a bivalent natural or unnatural amino acid residue or peptide attached to the amino acid residue linked to L¹and the amino acid residue linked to L²;

Loop B is a bivalent natural or unnatural amino acid residue or peptide attached to the amino acid residue linked to L¹and the amino acid residue linked to L³;

Spacer¹is a covalent bond, a natural or unnatural amino acid wherein the amino group is connected to the C-terminus of the Bicycle via an amide bond, or a peptide wherein the N-terminal amino group of the peptide is connected to the C-terminus of the Bicycle via an amide bond;

Spacer²is a covalent bond, a natural or unnatural amino acid wherein the acid is connected to the N-terminus of the Bicycle via an amide bond, or a peptide wherein the C-terminal acid of the peptide is connected to the N-terminus of the Bicycle via an amide bond;

each of R¹and R²is independently R,

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or -Linker-Conjugate;

each Linker is independently a covalent bond, or a C_1-8bivalent hydrocarbon chain wherein one, two or three methylene units of the chain are optionally and independently replaced by -Cy¹-, —S—, —N(R)—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —C(O)N(R)—, —N(R)C(O)—, —OC(O)N(R)—, —N(R)C(O)O—, —S(O)—, —S(O)₂—, —C(CH₃)═N—N(R)—, —N(R)N═C(CH₃)—, —N(R)CH₂C(O)—, —(CH₂CH₂O)_1-10—,

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each Conjugate is independently a half life extension motif, a solubilizing group, a transporter recognition motif, a cell penetrant motif, a drug payload, or a detectable moiety;

each of R³is independently hydrogen or C_1-4aliphatic;

m is 0 or 1; and

n is 0 or 1.

In certain embodiments, the present invention provides a compound of formula II:

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or a pharmaceutically acceptable salt thereof, wherein:

each of L²and L³is independently a covalent bond or a C_1-8bivalent hydrocarbon chain wherein one, two or three methylene units of the chain are optionally and independently replaced by -Cy¹-, —S—, —N(R)—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —C(O)N(R)—, —N(R)C(O)—, —OC(O)N(R)—, —N(R)C(O)O—, —S(O)—, —S(O)₂—, —C(CH₃)═N—N(R)—, —N(R)N═C(CH₃)—, —N(R)CH₂C(O)—, —(CH₂CH₂O)_1-10—,

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L⁴is a covalent bond, —O—, —N(R)—, or —N(R)CH₂CH₂N(R)—;

each R is independently hydrogen or C_1-4aliphatic;

each -Cy¹- is independently an optionally substituted bivalent ring selected from phenylene, 3-7 membered saturated or partially unsaturated carbocyclylene, 4-7 membered saturated or partially unsaturated heterocyclylene having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered saturated or partially unsaturated bicyclic heterocyclylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered saturated or partially unsaturated tricyclic heterocyclylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered partially saturated bicyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered partially saturated tricyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 9-12 membered bicyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 19-20 membered partially unsaturated tetracyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or 5-6 membered heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;

Scaffold is a trivalent group that connects and orients a cyclic peptide;

Loop C is a peptide attached to the amino acid residue linked to L²and the amino acid residue linked to L³;

Spacer¹is a covalent bond, a natural or unnatural amino acid wherein the amino group is connected to the C-terminus of the Bicycle via an amide bond, or a peptide wherein the N-terminal amino group of the peptide is connected to the C-terminus of the Bicycle via an amide bond;

Spacer²is a covalent bond, a natural or unnatural amino acid wherein the acid is connected to the N-terminus of the Bicycle via an amide bond, or a peptide wherein the C-terminal acid of the peptide is connected to the N-terminus of the Bicycle via an amide bond;

each of R¹and R²is independently R,

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or -Linker-Conjugate;

each Linker is independently a covalent bond, or a C_1-8bivalent hydrocarbon chain wherein one, two or three methylene units of the chain are optionally and independently replaced by -Cy¹-, —S—, —N(R)—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —C(O)N(R)—, —N(R)C(O)—, —OC(O)N(R)—, —N(R)C(O)O—, —S(O)—, —S(O)₂—, —C(CH₃)═N—N(R)—, —N(R)N═C(CH₃)—, —N(R)CH₂C(O)—, —(CH₂CH₂O)_1-10—,

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each Conjugate is independently a half life extension motif, a solubilizing group, a transporter recognition motif, a cell penetrant motif, a drug payload, or a detectable moiety;

each of R³is independently hydrogen or C_1-4aliphatic;

R⁵, together with the atom to which R⁵attaches to, form a moiety comprising a hydrogen bond acceptor (HBA) and/or a hydrogen bond donor (HBD), which forms a hydrogen bond with an amino acid residue of the peptide between L²and L³;

m is 0 or 1; and

n is 0 or 1

2. Compounds and Definitions

Peptide Ligands

A peptide ligand, as referred to herein, refers to a peptide covalently bound to a molecular scaffold. In some embodiments, a peptide comprises two or more reactive groups (e.g. cysteine and tyrosine residues) which are capable of forming covalent bonds to the scaffold, and a sequence subtended between said reactive groups which is referred to as the loop sequence, since it forms a loop when the peptide is bound to the scaffold. In some embodiments, a peptide ligand forms one or more loop via one or more hydrogen bond to the scaffold. In some embodiments, a peptide comprises two cysteine residues and forms one or more hydrogen bond to a scaffold, and thus forms at least two loops on the scaffold. In some embodiments, a peptide comprises at least three cysteine residues and forms at least two loops on the scaffold.

Advantages of the Peptide Ligands

Certain bicyclic peptides of the present invention have a number of advantageous properties which enable them to be considered as suitable drug-like molecules for injection, inhalation, nasal, ocular, oral or topical administration. Without being bound by any particular theory, such advantageous properties may include:

Species cross-reactivity. This is a typical requirement for preclinical pharmacodynamics and pharmacokinetic evaluation;

Protease stability. Bicyclic peptide ligands should ideally demonstrate stability to plasma proteases, epithelial (“membrane-anchored”) proteases, gastric and intestinal proteases, lung surface proteases, intracellular proteases and the like. Protease stability should be maintained between different species such that a bicycle lead candidate can be developed in animal models as well as administered with confidence to humans;

Desirable solubility profile. This is a function of the proportion of charged and hydrophilic versus hydrophobic residues and intra/inter-molecular H-bonding, which is important for formulation and absorption purposes;

An optimal plasma half-life in the circulation. Depending upon the clinical indication and treatment regimen, it may be required to develop a bicyclic peptide for short exposure in an acute illness management setting, or develop a bicyclic peptide with enhanced retention in the circulation, and is therefore optimal for the management of more chronic disease states. Other factors driving the desirable plasma half-life are requirements of sustained exposure for maximal therapeutic efficiency versus the accompanying toxicology due to sustained exposure of the agent; and

Selectivity. Certain peptide ligands of the invention demonstrate good selectivity over other carbonic anhydrases and metalloproteases.

Compounds of the present invention include those described generally herein, and are further illustrated by the classes, subclasses, and species disclosed herein. As used herein, the following definitions shall apply unless otherwise indicated. For purposes of this invention, the chemical elements are identified in accordance with the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75^thEd. Additionally, general principles of organic chemistry are described in “Organic Chemistry”, Thomas Sorrell, University Science Books, Sausalito: 1999, and “March's Advanced Organic Chemistry”, 5^thEd., Ed.: Smith, M. B. and March, J., John Wiley & Sons, New York: 2001, the entire contents of which are hereby incorporated by reference.

The term “aliphatic” or “aliphatic group”, as used herein, means a straight-chain (i.e., unbranched) or branched, substituted or unsubstituted hydrocarbon chain that is completely saturated or that contains one or more units of unsaturation, or a monocyclic hydrocarbon or bicyclic hydrocarbon that is completely saturated or that contains one or more units of unsaturation, but which is not aromatic (also referred to herein as “carbocycle,” “cycloaliphatic” or “cycloalkyl”), that has a single point of attachment to the rest of the molecule. Unless otherwise specified, aliphatic groups contain 1-6 aliphatic carbon atoms. In some embodiments, aliphatic groups contain 1-5 aliphatic carbon atoms. In other embodiments, aliphatic groups contain 1-4 aliphatic carbon atoms. In still other embodiments, aliphatic groups contain 1-3 aliphatic carbon atoms, and in yet other embodiments, aliphatic groups contain 1-2 aliphatic carbon atoms. In some embodiments, “cycloaliphatic” (or “carbocycle” or “cycloalkyl”) refers to a monocyclic C₃-C₆hydrocarbon that is completely saturated or that contains one or more units of unsaturation, but which is not aromatic, that has a single point of attachment to the rest of the molecule. Suitable aliphatic groups include, but are not limited to, linear or branched, substituted or unsubstituted alkyl, alkenyl, alkynyl groups and hybrids thereof such as (cycloalkyl)alkyl, (cycloalkenyl)alkyl or (cycloalkyl)alkenyl.

As used herein, the term “bridged bicyclic” refers to any bicyclic ring system, i.e. carbocyclic or heterocyclic, saturated or partially unsaturated, having at least one bridge. As defined by IUPAC, a “bridge” is an unbranched chain of atoms or an atom or a valence bond connecting two bridgeheads, where a “bridgehead” is any skeletal atom of the ring system which is bonded to three or more skeletal atoms (excluding hydrogen). In some embodiments, a bridged bicyclic group has 7-12 ring members and 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. Such bridged bicyclic groups are well known in the art and include those groups set forth below where each group is attached to the rest of the molecule at any substitutable carbon or nitrogen atom. Unless otherwise specified, a bridged bicyclic group is optionally substituted with one or more substituents as set forth for aliphatic groups. Additionally or alternatively, any substitutable nitrogen of a bridged bicyclic group is optionally substituted. Exemplary bridged bicyclics include:

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The term “lower alkyl” refers to a C_1-4straight or branched alkyl group. Exemplary lower alkyl groups are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, and tert-butyl.

The term “lower haloalkyl” refers to a C_1-4straight or branched alkyl group that is substituted with one or more halogen atoms.

The term “heteroatom” means one or more of oxygen, sulfur, nitrogen, phosphorus, or silicon (including, any oxidized form of nitrogen, sulfur, phosphorus, or silicon; the quaternized form of any basic nitrogen or; a substitutable nitrogen of a heterocyclic ring, for example N (as in 3,4-dihydro-2H-pyrrolyl), NH (as in pyrrolidinyl) or NR⁺ (as in N-substituted pyrrolidinyl)).

The term “unsaturated,” as used herein, means that a moiety has one or more units of unsaturation.

As used herein, the term “bivalent C_1-8(or C₁-6) hydrocarbon chain”, refers to bivalent alkylene, alkenylene, and alkynylene chains that are straight or branched as defined herein.

The term “alkylene” refers to a bivalent alkyl group. An “alkylene chain” is a polymethylene group, i.e., —(CH₂)_n—, wherein n is a positive integer, preferably from 1 to 6, from 1 to 4, from 1 to 3, from 1 to 2, or from 2 to 3. A substituted alkylene chain is a polymethylene group in which one or more methylene hydrogen atoms are replaced with a substituent. Suitable substituents include those described below for a substituted aliphatic group.

The term “alkenylene” refers to a bivalent alkenyl group. A substituted alkenylene chain is a polymethylene group containing at least one double bond in which one or more hydrogen atoms are replaced with a substituent. Suitable substituents include those described below for a substituted aliphatic group.

As used herein, the term “cyclopropylenyl” refers to a bivalent cyclopropyl group of the following structure:

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The term “halogen” means F, Cl, Br, or I.

The term “aryl” used alone or as part of a larger moiety as in “aralkyl,” “aralkoxy,” or “aryloxyalkyl,” refers to monocyclic or bicyclic ring systems having a total of five to fourteen ring members, wherein at least one ring in the system is aromatic and wherein each ring in the system contains 3 to 7 ring members. The term “aryl” may be used interchangeably with the term “aryl ring.” In certain embodiments of the present invention, “aryl” refers to an aromatic ring system which includes, but not limited to, phenyl, biphenyl, naphthyl, anthracyl and the like, which may bear one or more substituents. Also included within the scope of the term “aryl,” as it is used herein, is a group in which an aromatic ring is fused to one or more non-aromatic rings, such as indanyl, phthalimidyl, naphthimidyl, phenanthridinyl, or tetrahydronaphthyl, and the like.

The terms “heteroaryl” and “heteroar-,” used alone or as part of a larger moiety, e.g., “heteroaralkyl,” or “heteroaralkoxy,” refer to groups having 5 to 10 ring atoms, preferably 5, 6, or 9 ring atoms; having 6, 10, or 14 π electrons shared in a cyclic array; and having, in addition to carbon atoms, from one to five heteroatoms. The term “heteroatom” refers to nitrogen, oxygen, or sulfur, and includes any oxidized form of nitrogen or sulfur, and any quaternized form of a basic nitrogen. Heteroaryl groups include, without limitation, thienyl, furanyl, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, isothiazolyl, thiadiazolyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, indolizinyl, purinyl, naphthyridinyl, and pteridinyl. The terms “heteroaryl” and “heteroar-”, as used herein, also include groups in which a heteroaromatic ring is fused to one or more aryl, cycloaliphatic, or heterocyclyl rings, where the radical or point of attachment is on the heteroaromatic ring. Nonlimiting examples include indolyl, isoindolyl, benzothienyl, benzofuranyl, dibenzofuranyl, indazolyl, benzimidazolyl, benzthiazolyl, quinolyl, isoquinolyl, cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, 4H-quinolizinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, and pyrido[2,3-b]-1,4-oxazin-3(4H)-one. A heteroaryl group may be mono- or bicyclic. The term “heteroaryl” may be used interchangeably with the terms “heteroaryl ring,” “heteroaryl group,” or “heteroaromatic,” any of which terms include rings that are optionally substituted. The term “heteroaralkyl” refers to an alkyl group substituted by a heteroaryl, wherein the alkyl and heteroaryl portions independently are optionally substituted.

As used herein, the terms “heterocycle,” “heterocyclyl,” “heterocyclic radical,” and “heterocyclic ring” are used interchangeably and refer to a stable 5- to 7-membered monocyclic or 7-10-membered bicyclic heterocyclic moiety that is either saturated or partially unsaturated, and having, in addition to carbon atoms, one or more, preferably one to four, heteroatoms, as defined above. When used in reference to a ring atom of a heterocycle, the term “nitrogen” includes a substituted nitrogen. As an example, in a saturated or partially unsaturated ring having 0-3 heteroatoms selected from oxygen, sulfur or nitrogen, the nitrogen may be N (as in 3,4-dihydro-2H-pyrrolyl), NH (as in pyrrolidinyl), or +NR (as in N-substituted pyrrolidinyl).

A heterocyclic ring can be attached to its pendant group at any heteroatom or carbon atom that results in a stable structure and any of the ring atoms can be optionally substituted. Examples of such saturated or partially unsaturated heterocyclic radicals include, without limitation, tetrahydrofuranyl, tetrahydrothiophenyl pyrrolidinyl, piperidinyl, pyrrolinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, decahydroquinolinyl, oxazolidinyl, piperazinyl, dioxanyl, dioxolanyl, diazepinyl, oxazepinyl, thiazepinyl, morpholinyl, and quinuclidinyl. The terms “heterocycle,” “heterocyclyl,” “heterocyclyl ring,” “heterocyclic group,” “heterocyclic moiety,” and “heterocyclic radical,” are used interchangeably herein, and also include groups in which a heterocyclyl ring is fused to one or more aryl, heteroaryl, or cycloaliphatic rings, such as indolinyl, 3H-indolyl, chromanyl, phenanthridinyl, or tetrahydroquinolinyl. A heterocyclyl group may be mono- or bicyclic. The term “heterocyclylalkyl” refers to an alkyl group substituted by a heterocyclyl, wherein the alkyl and heterocyclyl portions independently are optionally substituted.

As used herein, the term “partially unsaturated” refers to a ring moiety that includes at least one double or triple bond. The term “partially unsaturated” is intended to encompass rings having multiple sites of unsaturation, but is not intended to include aryl or heteroaryl moieties, as herein defined.

As described herein, compounds of the invention may contain “optionally substituted” moieties. In general, the term “substituted,” whether preceded by the term “optionally” or not, means that one or more hydrogens of the designated moiety are replaced with a suitable substituent. Unless otherwise indicated, an “optionally substituted” group may have a suitable substituent at each substitutable position of the group, and when more than one position in any given structure may be substituted with more than one substituent selected from a specified group, the substituent may be either the same or different at every position. Combinations of substituents envisioned by this invention are preferably those that result in the formation of stable or chemically feasible compounds. The term “stable,” as used herein, refers to compounds that are not substantially altered when subjected to conditions to allow for their production, detection, and, in certain embodiments, their recovery, purification, and use for one or more of the purposes disclosed herein.

Suitable monovalent substituents on a substitutable carbon atom of an “optionally substituted” group are independently halogen; —(CH₂)_0-4R^∘; —(CH₂)_0-4OR^∘; —O(CH₂)_0-4R^∘, —O—(CH₂)_0-4C(O)OR^∘; —(CH₂)_0-4CH(OR^∘)₂; —(CH₂)_0-4SR^∘; —(CH₂)_0-4Ph, which may be substituted with R^∘; —(CH₂)_0-4O(CH₂)_0-1Ph which may be substituted with R^∘; —CH═CHPh, which may be substituted with R^∘; —(CH₂)_0-4O(CH₂)_0-1-pyridyl which may be substituted with R^∘; —NO₂; —CN; —N₃; —(CH₂)_0-4N(R^∘)₂; —(CH₂)_0-4N(R^∘)C(O)R^∘; —N(R^∘)C(S)R^∘; —N(R^∘)C(NR^∘)N(R^∘)₂; —(CH₂)_0-4N(R^∘)C(O)NR^∘₂; —N(R^∘)C(S)NR^∘₂; —(CH₂)_0-4N(R)C(O)OR^∘; —N(R^∘)N(R^∘)C(O)R^∘; —N(R^∘)N(R^∘)C(O)NR^∘₂; —N(R^∘)N(R^∘)C(O)OR^∘; —(CH₂)_0-4C(O)R^∘; —C(S)R^∘; —(CH₂)_0-4C(O)OR^∘; —(CH₂)_0-4C(O)SR^∘; —(CH₂)_0-4C(O)OSiR^∘₃; —(CH₂)_0-4OC(O)R^∘; —OC(O)(CH₂)_0-4SR—, —SC(S)SR^∘; —(CH₂)_0-4SC(O)R^∘; —(CH₂)_0-4C(O)NR^∘₂; —C(S)NR^∘₂; —C(S)SR^∘; —(CH₂)_0-4OC(O)NR^∘₂; —C(O)N(OR^∘)R^∘; —C(O)C(O)R^∘; —C(O)CH₂C(O)R^∘; —C(NOR^∘)R^∘; —(CH₂)_0-4SSR^∘; —(CH₂)_0-4S(O)₂R^∘; —(CH₂)_0-4S(O)₂OR^∘; —(CH₂)_0-4OS(O)₂R^∘; —S(O)₂NR^∘₂; —(CH₂)_0-4S(O)R^∘; —N(R^∘)S(O)₂NR^∘₂; —N(R^∘)S(O)₂R^∘; —N(OR^∘)R^∘; —C(NH)NR^∘₂; —P(O)₂R^∘; —P(O)R^∘₂; —OP(O)R^∘₂; —OP(O)(OR^∘)₂; —SiR^∘₃; —(C_1-4straight or branched alkylene)O—N(R^∘)₂; or —(C_1-4straight or branched alkylene)C(O)O—N(R^∘)₂, wherein each R^∘ may be substituted as defined below and is independently hydrogen, C_1-6aliphatic, —CH₂Ph, —O(CH₂)_0-1Ph, —CH₂-(5-6 membered heteroaryl ring), or a 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or, notwithstanding the definition above, two independent occurrences of R^∘, taken together with their intervening atom(s), form a 3-12-membered saturated, partially unsaturated, or aryl mono- or bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, which may be substituted as defined below.

Suitable monovalent substituents on R^∘ (or the ring formed by taking two independent occurrences of R^∘ together with their intervening atoms), are independently halogen, —(CH₂)_0-2R^●, -(haloR^●), —(CH₂)_0-2OH, —(CH₂)_0-2OR^●, —(CH₂)_0-2CH(OR^●)₂; —O(haloR^●), —CN, —N₃, —(CH₂)_0-2C(O)R^●, —(CH₂)_0-2C(O)OH, —(CH₂)_0-2C(O)OR^●, —(CH₂)_0-2SR^●, —(CH₂)_0-2SH, —(CH₂)_0-2NH₂, —(CH₂)_0-2NHR^●, —(CH₂)_0-2NR^●₂, —NO₂, —SiR^●₃, —OSiR^●₃, —C(O)SR^●, —(C_1-4straight or branched alkylene)C(O)OR^●, or —SSR^● wherein each R^● is unsubstituted or where preceded by “halo” is substituted only with one or more halogens, and is independently selected from C_1-4aliphatic, —CH₂Ph, —O(CH₂)_0-1Ph, or a 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. Suitable divalent substituents on a saturated carbon atom of R^● include ═O and ═S.

Suitable divalent substituents on a saturated carbon atom of an “optionally substituted” group include the following: ═O, ═S, ═NNR*₂, ═NNHC(O)R*, ═NNHC(O)OR*, ═NNHS(O)₂R*, ═NR*, ═NOR*, —O(C(R*₂))_2-3O—, or —S(C(R*₂))_2-3S—, wherein each independent occurrence of R* is selected from hydrogen, C_1-6aliphatic which may be substituted as defined below, or an unsubstituted 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. Suitable divalent substituents that are bound to vicinal substitutable carbons of an “optionally substituted” group include: —O(CR*₂)_2-3O—, wherein each independent occurrence of R* is selected from hydrogen, C_1-6aliphatic which may be substituted as defined below, or an unsubstituted 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

Suitable substituents on the aliphatic group of R* include halogen, —R^●, -(haloR^●), —OH, —OR^●, —O(haloR^●), —CN, —C(O)OH, —C(O)OR^●, —NH₂, —NHR^●, —NR^●₂, or —NO₂, wherein each R^● is unsubstituted or where preceded by “halo” is substituted only with one or more halogens, and is independently C_1-4aliphatic, —CH₂Ph, —O(CH₂)_0-1Ph, or a 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

Suitable substituents on a substitutable nitrogen of an “optionally substituted” group include —R^†, —NR^†₂, —C(O)R^†, —C(O)OR^†, —C(O)C(O)R^†, —C(O)CH₂C(O)R^†, —S(O)₂R^†, —S(O)₂NR^†₂, —C(S)NR^†₂, —C(NH)NR^†₂, or —N(R^†)S(O)₂R^†; wherein each R^† is independently hydrogen, C_1-6aliphatic which may be substituted as defined below, unsubstituted —OPh, or an unsubstituted 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or, notwithstanding the definition above, two independent occurrences of R^†, taken together with their intervening atom(s) form an unsubstituted 3-12-membered saturated, partially unsaturated, or aryl mono- or bicyclic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

Suitable substituents on the aliphatic group of R^† are independently halogen, —R^●, -(haloR^●), —OH, —OR^●, —O(haloR^●), —CN, —C(O)OH, —C(O)OR^●, —NH₂, —NHR^●, —NR^●₂, or —NO₂, wherein each R^● is unsubstituted or where preceded by “halo” is substituted only with one or more halogens, and is independently C_1-4aliphatic, —CH₂Ph, —O(CH₂)_0-1Ph, or a 5-6-membered saturated, partially unsaturated, or aryl ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

As used herein, the term “pharmaceutically acceptable salt” refers to those salts which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit/risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, S. M. Berge et al., describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66, 1-19, incorporated herein by reference. Pharmaceutically acceptable salts of the compounds of this invention include those derived from suitable inorganic and organic acids and bases. Examples of pharmaceutically acceptable, nontoxic acid addition salts are salts of an amino group formed with inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid and perchloric acid or with organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid or malonic acid or by using other methods used in the art such as ion exchange. Other pharmaceutically acceptable salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate salts, and the like.

Salts derived from appropriate bases include alkali metal, alkaline earth metal, ammonium and N⁺(C_1-4alkyl)₄salts. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. Further pharmaceutically acceptable salts include, when appropriate, nontoxic ammonium, quaternary ammonium, and amine cations formed using counterions such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, loweralkyl sulfonate and aryl sulfonate.

Unless otherwise stated, structures depicted herein are also meant to include all isomeric (e.g., enantiomeric, diastereomeric, and geometric (or conformational)) forms of the structure; for example, the R and S configurations for each asymmetric center, Z and E double bond isomers, and Z and E conformational isomers. Therefore, single stereochemical isomers as well as enantiomeric, diastereomeric, and geometric (or conformational) mixtures of the present compounds are within the scope of the invention. Unless otherwise stated, all tautomeric forms of the compounds of the invention are within the scope of the invention. Additionally, unless otherwise stated, structures depicted herein are also meant to include compounds that differ only in the presence of one or more isotopically enriched atoms. For example, compounds having the present structures including the replacement of hydrogen by deuterium or tritium, or the replacement of a carbon by a ¹³C- or ¹⁴C-enriched carbon are within the scope of this invention. Such compounds are useful, for example, as analytical tools, as probes in biological assays, or as therapeutic agents in accordance with the present invention. In certain embodiments, Rx, of a provided compound comprises one or more deuterium atoms.

As used herein, the term “inhibitor” is defined as a compound that binds to and/or inhibits CAIX, MT1-MMP, CD38, EphA2, or PBP1A with measurable affinity. In certain embodiments, an inhibitor has an IC₅₀and/or binding constant of less than about 50 μM, less than about 1 μM, less than about 500 nM, less than about 100 nM, less than about 10 nM, or less than about 1 nM.

A compound of the present invention may be tethered to a detectable moiety. It will be appreciated that such compounds are useful as imaging agents. One of ordinary skill in the art will recognize that a detectable moiety may be attached to a provided compound via a suitable substituent. As used herein, the term “suitable substituent” refers to a moiety that is capable of covalent attachment to a detectable moiety. Such moieties are well known to one of ordinary skill in the art and include groups containing, e.g., a carboxylate moiety, an amino moiety, a thiol moiety, or a hydroxyl moiety, to name but a few. It will be appreciated that such moieties may be directly attached to a provided compound or via a tethering group, such as a bivalent saturated or unsaturated hydrocarbon chain. In some embodiments, such moieties may be attached via click chemistry. In some embodiments, such moieties may be attached via a 1,3-cycloaddition of an azide with an alkyne, optionally in the presence of a copper catalyst. Methods of using click chemistry are known in the art and include those described by Rostovtsev et al., Angew. Chem. Int. Ed. 2002, 41, 2596-99 and Sun et al., Bioconjugate Chem., 2006, 17, 52-57.

As used herein, the term “detectable moiety” is used interchangeably with the term “label” and relates to any moiety capable of being detected, e.g., primary labels and secondary labels. Primary labels, such as radioisotopes (e.g., tritium, ³²P, ³³P, ³⁵S, or ¹⁴C), mass-tags, and fluorescent labels are signal generating reporter groups which can be detected without further modifications. Detectable moieties also include luminescent and phosphorescent groups.

The term “secondary label” as used herein refers to moieties such as biotin and various protein antigens that require the presence of a second intermediate for production of a detectable signal. For biotin, the secondary intermediate may include streptavidin-enzyme conjugates. For antigen labels, secondary intermediates may include antibody-enzyme conjugates. Some fluorescent groups act as secondary labels because they transfer energy to another group in the process of nonradiative fluorescent resonance energy transfer (FRET), and the second group produces the detected signal.

The terms “fluorescent label”, “fluorescent dye”, and “fluorophore” as used herein refer to moieties that absorb light energy at a defined excitation wavelength and emit light energy at a different wavelength. Examples of fluorescent labels include, but are not limited to: Alexa Fluor dyes (Alexa Fluor 350, Alexa Fluor 488, Alexa Fluor 532, Alexa Fluor 546, Alexa Fluor 568, Alexa Fluor 594, Alexa Fluor 633, Alexa Fluor 660 and Alexa Fluor 680), AMCA, AMCA-S, BODIPY dyes (BODIPY FL, BODIPY R6G, BODIPY TMR, BODIPY TR, BODIPY 530/550, BODIPY 558/568, BODIPY 564/570, BODIPY 576/589, BODIPY 581/591, BODIPY 630/650, BODIPY 650/665), Carboxyrhodamine 6G, carboxy-X-rhodamine (ROX), Cascade Blue, Cascade Yellow, Coumarin 343, Cyanine dyes (Cy3, Cy5, Cy3.5, Cy5.5), Dansyl, Dapoxyl, Dialkylaminocoumarin, 4′,5′-Dichloro-2′,7′-dimethoxy-fluorescein, DM-NERF, Eosin, Erythrosin, Fluorescein, FAM, Hydroxycoumarin, IRDyes (IRD40, IRD 700, IRD 800), JOE, Lissamine rhodamine B, Marina Blue, Methoxycoumarin, Naphthofluorescein, Oregon Green 488, Oregon Green 500, Oregon Green 514, Pacific Blue, PyMPO, Pyrene, Rhodamine B, Rhodamine 6G, Rhodamine Green, Rhodamine Red, Rhodol Green, 2′,4′,5′,7′-Tetra-bromosulfone-fluorescein, Tetramethyl-rhodamine (TMR), Carboxytetramethylrhodamine (TAMRA), Texas Red, Texas Red-X.

The term “mass-tag” as used herein refers to any moiety that is capable of being uniquely detected by virtue of its mass using mass spectrometry (MS) detection techniques. Examples of mass-tags include electrophore release tags such as N-[3-[4′-[(p-Methoxytetrafluorobenzyl)oxy]phenyl]-3-methylglyceronyl]isonipecotic Acid, 4′-[2,3,5,6-Tetrafluoro-4-(pentafluorophenoxyl)]methyl acetophenone, and their derivatives. The synthesis and utility of these mass-tags is described in U.S. Pat. Nos. 4,650,750, 4,709,016, 5,360,8191, 5,516,931, 5,602,273, 5,604,104, 5,610,020, and 5,650,270. Other examples of mass-tags include, but are not limited to, nucleotides, dideoxynucleotides, oligonucleotides of varying length and base composition, oligopeptides, oligosaccharides, and other synthetic polymers of varying length and monomer composition. A large variety of organic molecules, both neutral and charged (biomolecules or synthetic compounds) of an appropriate mass range (100-2000 Daltons) may also be used as mass-tags.

The terms “measurable affinity” and “measurably inhibit,” as used herein, means a measurable change in CAIX, MT1-MMP, CD38, EphA2, or PBP1A activity between a sample comprising a compound of the present invention, or composition thereof, and CAIX, MT1-MMP, CD38, EphA2, or PBP1A, and an equivalent sample comprising CAIX, MT1-MMP, CD38, EphA2, or PBP1A, in the absence of said compound, or composition thereof.

The term “hydrogen bond,” as used herein, means a weak type of force that forms a special type of dipole-dipole attraction which occurs when a hydrogen atom bonded to a strongly electronegative atom exists in the vicinity of another electronegative atom with a lone pair of electrons. In order for a hydrogen bond to occur there must be both a hydrogen donor and an acceptor present. The donor in a hydrogen bond is the atom to which the hydrogen atom participating in the hydrogen bond is covalently bonded, and is usually a strongly electronegative atom such as N, O, or F. The hydrogen acceptor is the neighboring electronegative ion or molecule, and must posses a lone electron pair in order to form a hydrogen bond.

3. Description of Exemplary Embodiments

In certain embodiments, the present invention provides a compound of formula I:

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or a pharmaceutically acceptable salt thereof, wherein:

each of L¹, L², and L³is independently a covalent bond or a C_1-8bivalent hydrocarbon chain wherein one, two or three methylene units of the chain are optionally and independently replaced by -Cy¹-, —S—, —N(R)—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —C(O)N(R)—, —N(R)C(O)—, —OC(O)N(R)—, —N(R)C(O)O—, —S(O)—, —S(O)₂—, —C(CH₃)═N—N(R)—, —N(R)N═C(CH₃)—, —N(R)CH₂C(O)—, —(CH₂CH₂O)_1-10—,

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L⁴is a covalent bond, —O—, —N(R)—, or —N(R)CH₂CH₂N(R)—;

each R is independently hydrogen or C_1-4aliphatic;

each -Cy¹- is independently an optionally substituted bivalent ring selected from phenylene, 3-7 membered saturated or partially unsaturated carbocyclylene, 4-7 membered saturated or partially unsaturated heterocyclylene having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered saturated or partially unsaturated bicyclic heterocyclylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered saturated or partially unsaturated tricyclic heterocyclylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered partially saturated bicyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered partially saturated tricyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 9-12 membered bicyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 19-20 membered partially unsaturated tetracyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or 5-6 membered heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;

Scaffold is a trivalent group that connects and orients a cyclic peptide;

Loop A is a bivalent natural or unnatural amino acid residue or peptide attached to the amino acid residue linked to L¹and the amino acid residue linked to L²;

Loop B is a bivalent natural or unnatural amino acid residue or peptide attached to the amino acid residue linked to L¹and the amino acid residue linked to L³;

Spacer¹is a covalent bond, a natural or unnatural amino acid wherein the amino group is connected to the C-terminus of the Bicycle via an amide bond, or a peptide wherein the N-terminal amino group of the peptide is connected to the C-terminus of the Bicycle via an amide bond;

Spacer²is a covalent bond, a natural or unnatural amino acid wherein the acid is connected to the N-terminus of the Bicycle via an amide bond, or a peptide wherein the C-terminal acid of the peptide is connected to the N-terminus of the Bicycle via an amide bond;

each of R¹and R²is independently R,

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or -Linker-Conjugate;

each Linker is independently a covalent bond, or a C_1-8bivalent hydrocarbon chain wherein one, two or three methylene units of the chain are optionally and independently replaced by -Cy¹-, —S—, —N(R)—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —C(O)N(R)—, —N(R)C(O)—, —OC(O)N(R)—, —N(R)C(O)O—, —S(O)—, —S(O)₂—, —C(CH₃)═N—N(R)—, —N(R)N═C(CH₃)—, —N(R)CH₂C(O)—, —(CH₂CH₂O)_1-10—,

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each Conjugate is independently a half life extension motif, a solubilizing group, a transporter recognition motif, a cell penetrant motif, a drug payload, or a detectable moiety;

each of R³is independently hydrogen or C_1-4aliphatic;

m is 0 or 1; and

n is 0 or 1

As defined above and described herein, each of L¹, L², and L³is independently a covalent bond or a C_1-8bivalent hydrocarbon chain wherein one, two or three methylene units of the chain are optionally and independently replaced by -Cy¹-, —S—, —N(R)—, —O—, —C(O)—, —OC(O)—, —C(O)O—, —C(O)N(R)—, —N(R)C(O)—, —OC(O)N(R)—, —N(R)C(O)O—, —S(O)—, —S(O)₂—, —C(CH₃)═N—N(R)—, —N(R)N═C(CH₃)—, —N(R)CH₂C(O)—, —(CH₂CH₂O)_1-10—,

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In some embodiments, each of L¹, L², and L³is a covalent bond. In some embodiments, each of L¹, L², and L³is —CH₂S—. In some embodiments, each of L¹, L², and L³is —CH₂NH—. In some embodiments, each of L¹, L², and L³is —CH₂O—. In some embodiments, each of L¹, L², and L³is —CH₂CH₂O—. In some embodiments, each of L¹, L², and L³is —CH₂CH₂CH₂CH₂NH—. In some embodiments, each of L¹, L², and L³is —CH₂N(CH₃)—. In some embodiments, each of L¹, L², and L³is —CH₂CH₂CH₂CH₂N(CH₃)—. In some embodiments, each of L¹, L², and L³is

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In some embodiments, L¹is a covalent bond. In some embodiments, L¹is —CH₂S—. In some embodiments, L¹is —CH₂O—. In some embodiments, L¹is —CH₂CH₂O—. In some embodiments, L¹is —CH₂NH—. In some embodiments, L¹is —CH₂CH₂CH₂CH₂NH—. In some embodiments, L¹is —CH₂N(CH₃)—. In some embodiments, L¹is —CH₂CH₂CH₂CH₂N(CH₃)—. In some embodiments, L¹is —CH₂SCH₂—. In some embodiments, L¹is —CH₂OCH₂—. In some embodiments, L¹is —CH₂CH₂OCH₂—. In some embodiments, L¹is —CH₂NHCH₂—. In some embodiments, L¹is —CH₂N(CH₃)CH₂—. In some embodiments, L¹is —CH₂CH₂CH₂CH₂NHCH₂—. In some embodiments, L¹is —CH₂CH₂CH₂CH₂N(CH₃)CH₂—. In some embodiments, L¹is —CH₂SCH₂C(O)NH—. In some embodiments, L¹is —CH₂OCH₂C(O)NH—. In some embodiments, L¹is —CH₂CH₂OCH₂C(O)NH—. In some embodiments, L¹is —CH₂NHCH₂C(O)NH—. In some embodiments, L¹is —CH₂N(CH₃)CH₂C(O)NH—. In some embodiments, L¹is —CH₂CH₂CH₂CH₂NHCH₂C(O)NH—. In some embodiments, L¹is —CH₂CH₂CH₂CH₂N(CH₃)CH₂C(O)NH—. In some embodiments, L¹is —CH₂SCH₂C(O)—. In some embodiments, L¹is —CH₂OCH₂C(O)—. In some embodiments, L¹is —CH₂CH₂OCH₂C(O)—. In some embodiments, L¹is —CH₂NHCH₂C(O)—. In some embodiments, L¹is —CH₂N(CH₃)CH₂C(O)—. In some embodiments, L¹is —CH₂CH₂CH₂CH₂NHCH₂C(O)—. In some embodiments, L¹is —CH₂CH₂CH₂CH₂N(CH₃)CH₂C(O)—. In some embodiments, L¹is —CH₂SCH₂CH₂C(O)NH—. In some embodiments, L¹is —CH₂OCH₂CH₂C(O)NH—. In some embodiments, L¹is —CH₂CH₂OCH₂CH₂C(O)NH—. In some embodiments, L¹is —CH₂NHCH₂CH₂C(O)NH—. In some embodiments, L¹is —CH₂N(CH₃)CH₂CH₂C(O)NH—. In some embodiments, L¹is —CH₂CH₂CH₂CH₂NHCH₂CH₂C(O)NH—. In some embodiments, L¹is —CH₂CH₂CH₂CH₂N(CH₃)CH₂CH₂C(O)NH—. In some embodiments, L¹is —CH₂SCH₂CH₂C(O)—. In some embodiments, L¹is —CH₂OCH₂CH₂C(O)—. In some embodiments, L¹is —CH₂CH₂OCH₂CH₂C(O)—. In some embodiments, L¹is —CH₂NHCH₂CH₂C(O)—. In some embodiments, L¹is —CH₂N(CH₃)CH₂CH₂C(O)—. In some embodiments, L¹is —CH₂CH₂CH₂CH₂NHCH₂CH₂C(O)—. In some embodiments, L¹is —CH₂CH₂CH₂CH₂N(CH₃)CH₂CH₂C(O)—. In some embodiments, L¹is

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In some embodiments, L¹is selected from those depicted in Table 1, below.

In some embodiments, L²is a covalent bond. In some embodiments, L²is —CH₂S—. In some embodiments, L²is —CH₂O—. In some embodiments, L²is —CH₂CH₂O—. In some embodiments, L²is —CH₂NH—. In some embodiments, L²is —CH₂CH₂CH₂CH₂NH—. In some embodiments, L²is —CH₂N(CH₃)—. In some embodiments, L²is —CH₂CH₂CH₂CH₂N(CH₃)—. In some embodiments, L²is —CH₂SCH₂—. In some embodiments, L²is —CH₂OCH₂—. In some embodiments, L²is —CH₂CH₂OCH₂—. In some embodiments, L²is —CH₂NHCH₂—. In some embodiments, L²is —CH₂N(CH₃)CH₂—. In some embodiments, L²is —CH₂CH₂CH₂CH₂NHCH₂—. In some embodiments, L²is —CH₂CH₂CH₂CH₂N(CH₃)CH₂—. In some embodiments, L²is —CH₂SCH₂C(O)NH—. In some embodiments, L²is —CH₂OCH₂C(O)NH—. In some embodiments, L²is —CH₂CH₂OCH₂C(O)NH—. In some embodiments, L²is —CH₂NHCH₂C(O)NH—. In some embodiments, L²is —CH₂N(CH₃)CH₂C(O)NH—. In some embodiments, L²is —CH₂CH₂CH₂CH₂NHCH₂C(O)NH—. In some embodiments, L²is —CH₂CH₂CH₂CH₂N(CH₃)CH₂C(O)NH—. In some embodiments, L²is —CH₂SCH₂C(O)—. In some embodiments, L²is —CH₂OCH₂C(O)—. In some embodiments, L²is —CH₂CH₂OCH₂C(O)—. In some embodiments, L²is —CH₂NHCH₂C(O)—. In some embodiments, L²is —CH₂N(CH₃)CH₂C(O)—. In some embodiments, L²is —CH₂CH₂CH₂CH₂NHCH₂C(O)—. In some embodiments, L²is —CH₂CH₂CH₂CH₂N(CH₃)CH₂C(O)—. In some embodiments, L²is —CH₂SCH₂CH₂C(O)NH—. In some embodiments, L²is —CH₂OCH₂CH₂C(O)NH—. In some embodiments, L²is —CH₂CH₂OCH₂CH₂C(O)NH—. In some embodiments, L²is —CH₂NHCH₂CH₂C(O)NH—. In some embodiments, L²is —CH₂N(CH₃)CH₂CH₂C(O)NH—. In some embodiments, L²is —CH₂CH₂CH₂CH₂NHCH₂CH₂C(O)NH—. In some embodiments, L²is —CH₂CH₂CH₂CH₂N(CH₃)CH₂CH₂C(O)NH—. In some embodiments, L²is —CH₂SCH₂CH₂C(O)—. In some embodiments, L²is —CH₂OCH₂CH₂C(O)—. In some embodiments, L²is —CH₂CH₂OCH₂CH₂C(O)—. In some embodiments, L²is —CH₂NHCH₂CH₂C(O)—. In some embodiments, L²is —CH₂N(CH₃)CH₂CH₂C(O)—. In some embodiments, L²is —CH₂CH₂CH₂CH₂NHCH₂CH₂C(O)—. In some embodiments, L²is —CH₂CH₂CH₂CH₂N(CH₃)CH₂CH₂C(O)—. In some embodiments, L²is

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In some embodiments, L²is selected from those depicted in Table 1, below.

In some embodiments, L³is a covalent bond. In some embodiments, L³is —CH₂S—. In some embodiments, L³is —CH₂O—. In some embodiments, L³is —CH₂CH₂O—. In some embodiments, L³is —CH₂NH—. In some embodiments, L³is —CH₂CH₂CH₂CH₂NH—. In some embodiments, L³is —CH₂N(CH₃)—. In some embodiments, L³is —CH₂CH₂CH₂CH₂N(CH₃)—. In some embodiments, L³is —CH₂SCH₂—. In some embodiments, L³is —CH₂OCH₂—. In some embodiments, L³is —CH₂CH₂OCH₂—. In some embodiments, L³is —CH₂NHCH₂—. In some embodiments, L³is —CH₂N(CH₃)CH₂—. In some embodiments, L³is —CH₂CH₂CH₂CH₂NHCH₂—. In some embodiments, L³is —CH₂CH₂CH₂CH₂N(CH₃)CH₂—. In some embodiments, L³is —CH₂SCH₂C(O)NH—. In some embodiments, L³is —CH₂OCH₂C(O)NH—. In some embodiments, L³is —CH₂CH₂OCH₂C(O)NH—. In some embodiments, L³is —CH₂NHCH₂C(O)NH—. In some embodiments, L³is —CH₂N(CH₃)CH₂C(O)NH—. In some embodiments, L³is —CH₂CH₂CH₂CH₂NHCH₂C(O)NH—. In some embodiments, L³is —CH₂CH₂CH₂CH₂N(CH₃)CH₂C(O)NH—. In some embodiments, L³is —CH₂SCH₂C(O)—. In some embodiments, L³is —CH₂OCH₂C(O)—. In some embodiments, L³is —CH₂CH₂OCH₂C(O)—. In some embodiments, L³is —CH₂NHCH₂C(O)—. In some embodiments, L³is —CH₂N(CH₃)CH₂C(O)—. In some embodiments, L³is —CH₂CH₂CH₂CH₂NHCH₂C(O)—. In some embodiments, L³is —CH₂CH₂CH₂CH₂N(CH₃)CH₂C(O)—. In some embodiments, L³is —CH₂SCH₂CH₂C(O)NH—. In some embodiments, L³is —CH₂OCH₂CH₂C(O)NH—. In some embodiments, L³is —CH₂CH₂OCH₂CH₂C(O)NH—. In some embodiments, L³is —CH₂NHCH₂CH₂C(O)NH—. In some embodiments, L³is —CH₂N(CH₃)CH₂CH₂C(O)NH—. In some embodiments, L³is —CH₂CH₂CH₂CH₂NHCH₂CH₂C(O)NH—. In some embodiments, L³is —CH₂CH₂CH₂CH₂N(CH₃)CH₂CH₂C(O)NH—. In some embodiments, L³is —CH₂SCH₂CH₂C(O)—. In some embodiments, L³is —CH₂OCH₂CH₂C(O)—. In some embodiments, L³is —CH₂CH₂OCH₂CH₂C(O)—. In some embodiments, L³is —CH₂NHCH₂CH₂C(O)—. In some embodiments, L³is —CH₂N(CH₃)CH₂CH₂C(O)—. In some embodiments, L³is —CH₂CH₂CH₂CH₂NHCH₂CH₂C(O)—. In some embodiments, L³is —CH₂CH₂CH₂CH₂N(CH₃)CH₂CH₂C(O)—. In some embodiments, L³is

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In some embodiments, L³is selected from those depicted in Table 1, below.

As defined above and described herein, L⁴is a covalent bond, —O—, —N(R)—, or —N(R)CH₂CH₂N(R)—.

In some embodiments, L⁴is a covalent bond. In some embodiments, L⁴is —O—. In some embodiments, L⁴is —N(R)—, wherein R is as described herein. In some embodiments, L⁴is —N(R)CH₂CH₂N(R)—, wherein R is as described herein.

In some embodiments, L⁴is —NH—. In some embodiments, L⁴is —NHCH₂CH₂NH—.

In some embodiments, L⁴is selected from those depicted in Table 1, below.

As defined above and described herein, each R is independently hydrogen or C_1-4aliphatic.

In some embodiments, R is H. In some embodiments, R is C_1-4aliphatic.

In some embodiments, R is C_1-4alkyl. In some embodiments, R is methyl. In some embodiments, R is ethyl. In some embodiments, R is isopropyl. In some embodiments, R is propyl. In some embodiments, R is butyl. In some embodiments, R is isobutyl. In some embodiments, R is t-butyl.

In some embodiments, R is selected from those depicted in Table 1, below.

As defined above and described herein, each -Cy¹- is independently an optionally substituted bivalent ring selected from phenylene, 3-7 membered saturated or partially unsaturated carbocyclylene, 4-7 membered saturated or partially unsaturated heterocyclylene having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered saturated or partially unsaturated bicyclic heterocyclylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered saturated or partially unsaturated tricyclic heterocyclylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered partially saturated bicyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 10-12 membered partially saturated tricyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 9-12 membered bicyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, 19-20 membered partially unsaturated tetracyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur, or 5-6 membered heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, -Cy¹- is an optionally substituted phenylene. In some embodiments, -Cy¹- is an optionally substituted 3-7 membered saturated or partially unsaturated carbocyclylene. In some embodiments, -Cy¹- is an optionally substituted 4-7 membered saturated or partially unsaturated heterocyclylene having 1-2 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, -Cy¹- is an optionally substituted 10-12 membered saturated or partially unsaturated bicyclic heterocyclylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, -Cy¹- is an optionally substituted 10-12 membered saturated or partially unsaturated tricyclic heterocyclylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, -Cy¹- is an optionally substituted 10-12 membered partially saturated bicyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, -Cy¹- is an optionally substituted 10-12 membered partially saturated tricyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, -Cy¹- is an optionally substituted 9-12 membered bicyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, -Cy¹- is an optionally substituted 19-20 membered partially unsaturated tetracyclic heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur. In some embodiments, -Cy¹- is an optionally substituted 5-6 membered heteroarylene having 1-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur.

In some embodiments, -Cy¹- is selected from those depicted in Table 1, below.

As defined above and described herein, Scaffold is a trivalent group that connects and orients a cyclic peptide.