Compositions and uses thereof

Abstract

Provided herein are compounds of Formula (I): # imgabs0 # or a pharmaceutically acceptable salt thereof, wherein the variables of Formula (I) are as defined herein. Such compounds may be useful as anticancer agents.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 377,480, filed on September 28, 2022, and U.S. Provisional Patent Application No. 63 / 377,612, filed on September 29, 2022, each of which is hereby incorporated herein by reference in its entirety. Background Art

[0003] Currently, small cytotoxic molecules for antibody-drug conjugates can include camptothecin derivatives, which have antitumor effects by inhibiting topoisomerase I. Camptothecin derivatives can be used in antibody-drug conjugates (ADCs). However, there is still a need to further develop camptothecin derivatives and ADC drugs with better efficacy and / or higher safety. Summary of the Invention

[0004] In one aspect, the present disclosure provides a compound represented by formula (I),

[0005]

[0006] or a pharmaceutically acceptable salt thereof, wherein;

[0007] R 1 is selected from -O-CH2-CH2-O- and -NH-C(O)-CH2-O-;

[0008] L is L 2 -(L 2B ) z -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ;

[0009] L 2 is selected from C 1-6 alkylene;

[0010] L 2B is selected from NR 4 C(O)O-C 1-6 alkylene-phenylene, wherein the phenylene is optionally substituted with one or more R 5 substituents;

[0011] L 3 is selected from residues comprising 1 to 7 amino acids;

[0012] L 4Selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0013] L 5 Selected from (O-CH2-CH2-) q -(NR 3 ) s ;

[0014] L 6 Selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0015] L 7 Selected from C 5-6 carbocyclic olefins;

[0016] R 2 Selected from optionally substituted 5- to 6-membered heterocycles, wherein the 5- to 6-membered heterocycle is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0017] R 3 Selected from hydrogen and C 1-6 alkyl;

[0018] R 4 Selected from hydrogen and C 1-6 alkyl optionally substituted by one or more SO2C 1-6 alkyl;

[0019] Each R 5 is independently selected from sugars;

[0020] m is selected from 0 and 1;

[0021] n is selected from 0 and 1;

[0022] p is selected from 0 and 1;

[0023] q is selected from 0 to 8;

[0024] s is selected from 0 and 1; and

[0025] z is selected from 0 and 1.

[0026] In one aspect, the present disclosure provides a compound represented by formula (I)*,

[0027]

[0028] or a pharmaceutically acceptable salt thereof, wherein;

[0029] L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ;

[0030] L 2 is selected from C 1-6 alkylene;

[0031] L 3 is selected from residues containing 1 to 7 amino acids;

[0032] L 4 is selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0033] L 5 is selected from (O-CH2-CH2-) q -(NR 3 ) s ;

[0034] L 6 is selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 substituted by substituents of alkynyl;

[0035] L 7 selected from C 5-6 carbocyclic olefin;

[0036] R 2 selected from optionally substituted 5- to 6-membered heterocycles, wherein the 5- to 6-membered heterocycle is optionally substituted by one or more independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 substituted by substituents of alkynyl;

[0037] R 3 selected from hydrogen and C 1-6 alkyl;

[0038] m is selected from 0 and 1;

[0039] n is selected from 0 and 1;

[0040] p is selected from 0 and 1;

[0041] q is selected from 0 to 8; and

[0042] s is selected from 0 and 1.

[0043] In some embodiments, formula (I) is represented as

[0044]

[0045] or a pharmaceutically acceptable salt thereof.

[0046] In some embodiments, formula (I) is represented as

[0047]

[0048] or a pharmaceutically acceptable salt thereof.

[0049] In some embodiments, formula (I) is represented as

[0050]

[0051] or a pharmaceutically acceptable salt thereof, wherein;

[0052] Lg is a ligand.

[0053] In some embodiments, the present disclosure provides a compound of formula (III):

[0054]

[0055] or a pharmaceutically acceptable salt thereof, wherein;

[0056] Lg is a ligand;

[0057] R 1 is selected from -O-CH2-CH2-O- and -NH-C(O)-CH2-O-;

[0058] L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ;

[0059] L 2 is selected from C 1-6 alkylene;

[0060] L 3 is selected from residues comprising 1 to 7 amino acids;

[0061] L 4 is selected from optionally substituted C 1-6 alkylene, wherein the C 1-6 alkylene is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0062] L 5 is selected from -(O-CH2-CH2-) q -(NR 3 ) s -;

[0063] L 6 is selected from optionally substituted C 1-6 alkylene, wherein the C 1-6 alkylene is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C2-10 Substitution of the alkynyl group by a substituent;

[0064] L 7 Selected from C 5-6 carbocyclic olefin;

[0065] R 2 Selected from optionally substituted 5- to 6-membered heterocycles, wherein the 5- to 6-membered heterocycle is optionally substituted by one or more independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 Substitution of the alkynyl group by a substituent;

[0066] R 3 Selected from hydrogen and C 1-6 alkyl;

[0067] m is selected from 0 and 1;

[0068] n is selected from 0 and 1;

[0069] p is selected from 0 and 1;

[0070] q is selected from 0 to 8; and

[0071] s is selected from 0 and 1.

[0072] In some embodiments, formula (I)* is represented as

[0073]

[0074] or a pharmaceutically acceptable salt thereof, wherein;

[0075] Lg is a ligand.

[0076] In some embodiments, the present disclosure provides a compound of formula (IV)*:

[0077]

[0078] or a pharmaceutically acceptable salt thereof, wherein;

[0079] Lg is a ligand;

[0080] L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ;

[0081] L 2 selected from C 1-6 alkylene;

[0082] L 3 selected from residues containing 1 to 7 amino acids;

[0083] L 4 selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0084] L 5 selected from (O-CH2-CH2-) q -(NR 3 ) s ;

[0085] L 6 selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0086] L 7 selected from C 5-6 carbocyclic olefin;

[0087] R 2 selected from optionally substituted 5- to 6-membered heterocycles, wherein the 5- to 6-membered heterocycles are optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0088] R 3 selected from hydrogen and C 1-6 alkyl;

[0089] m is selected from 0 and 1;

[0090] n is selected from 0 and 1;

[0091] p is selected from 0 and 1;

[0092] q is selected from 0 to 8; and

[0093] s is selected from 0 and 1.

[0094] In some embodiments, the ligand is selected from an antibody or an antigen-binding fragment thereof. In some cases, the ligand is selected from chimeric antibodies, humanized antibodies, and fully human antibodies.

[0095] In some embodiments, the pharmaceutical composition comprises a compound or salt of formula (I), formula (I)*, formula (I-A), formula (I-B), formula (II), formula (II)*, formula (III), formula (III)*, formula (IV), formula (IV)*, formula (IV-A)*, formula (V-A), formula (V-B), formula (V-C), or formula (V-D), and a pharmaceutically acceptable excipient of any of them.

[0096] In some embodiments, the present disclosure provides a method for treating a subject having a tumor, comprising administering to a subject in need a compound or salt of formula (I), formula (I)*, formula (I-A), formula (I-B), formula (II), formula (II)*, formula (III), formula (III)*, formula (IV), formula (IV)*, formula (IV-A)*, formula (V-A), formula (V-B), formula (V-C), or formula (V-D), or a pharmaceutical composition of any of them.

[0097] In some embodiments, the present disclosure provides a method for treating a subject having a disease or disorder, comprising administering to a subject in need a compound or salt of formula (I), formula (I)*, formula (I-A), formula (I-B), formula (II), formula (II)*, formula (III), formula (III)*, formula (IV), formula (IV)*, formula (IV-A)*, formula (V-A), formula (V-B), formula (V-C), or formula (V-D), or a pharmaceutical composition of any of them.

[0098] In some embodiments, the present disclosure provides a method for treating a subject having cancer, comprising administering to a subject in need a compound or salt of formula (I), formula (I)*, formula (I-A), formula (I-B), formula (II), formula (II)*, formula (III), formula (III)*, formula (IV), formula (IV)*, formula (IV-A)*, formula (V-A), formula (V-B), formula (V-C), or formula (V-D), or a pharmaceutical composition of any of them.

[0099] Incorporation by Reference

[0100] All publications, patents, and patent applications mentioned in this specification are incorporated herein by reference to the extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. To the extent that the incorporated publications, patents, or patent applications conflict with the disclosure contained in this specification, this specification is intended to supersede and / or take precedence over any such conflicting material. BRIEF DESCRIPTION OF THE DRAWINGS

[0101] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth exemplary embodiments in which the principles of the invention are utilized, and the accompanying drawings (also referred to herein as "FIGURES" and "DRAWINGS"). In the drawings:

[0102] Figure 1 illustrates the stability of the ADC in mouse plasma;

[0103] Figure 2 illustrates the stability of the ADC in human plasma;

[0104] Figure 3 illustrates the in vivo anti-tumor activity of the ADC in a Jeko-1 xenograft model; and

[0105] Figure 4 illustrates the in vivo anti-tumor activity of ADC-3 in a SK-OV3 xenograft model. DETAILED DESCRIPTION

[0106] The following description sets forth numerous exemplary configurations, methods, parameters, etc. However, it should be understood that such description is not intended to limit the scope of the present disclosure, but is provided merely as a description of exemplary embodiments.

[0107] In the following description, certain specific details are set forth in order to provide a thorough understanding of the various embodiments of the present disclosure. However, those skilled in the art will understand that the present disclosure may be practiced without these details.

[0108] DEFINITIONS

[0109] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. All patents and publications cited herein are incorporated by reference.

[0110] "Alkyl" refers to a straight-chain or branched-chain hydrocarbon chain group consisting only of carbon and hydrogen atoms, containing no unsaturation, and preferably having from one to fifteen carbon atoms (i.e., C1-C 15 alkyl). In certain embodiments, alkyl contains from one to thirteen carbon atoms (i.e., C1-C 13(alkyl). In certain embodiments, the alkyl contains from one to eight carbon atoms (i.e., C1-C8 alkyl). In other embodiments, the alkyl contains from one to five carbon atoms (i.e., C1-C5 alkyl). In other embodiments, the alkyl contains from one to four carbon atoms (i.e., C1-C4 alkyl). In other embodiments, the alkyl contains from one to three carbon atoms (i.e., C1-C3 alkyl). In other embodiments, the alkyl contains from one to two carbon atoms (i.e., C1-C2 alkyl). In other embodiments, the alkyl contains one carbon atom (i.e., C1 alkyl). In other embodiments, the alkyl contains from five to fifteen carbon atoms (i.e., C5-C 15 (alkyl). In other embodiments, the alkyl contains from five to eight carbon atoms (i.e., C5-C8 alkyl). In other embodiments, the alkyl contains from two to five carbon atoms (i.e., C2-C5 alkyl). In other embodiments, the alkyl contains from three to five carbon atoms (i.e., C3-C5 alkyl). In certain embodiments, the alkyl group is selected from methyl, ethyl, 1-propyl (n-propyl), 1-methylethyl (isopropyl), 1-butyl (n-butyl), 1-methylpropyl (sec-butyl), 2-methylpropyl (isobutyl), 1,1-dimethylethyl (tert-butyl), 1-pentyl (n-pentyl). The alkyl is attached to the remainder of the molecule by a single bond.

[0111] The term "C x-y " when used in combination with a chemical moiety such as alkyl, alkenyl or alkynyl, means a group containing from x to y carbon atoms in the chain. For example, "C 1-6 alkyl" refers to a substituted or unsubstituted saturated hydrocarbon group, including straight-chain and branched-chain alkyl groups containing 1 to 6 carbon atoms. The term -C x-y alkylene- refers to a substituted or unsubstituted alkylene chain, where there are x to y carbon atoms in the alkylene chain. For example, -C 1-6 alkylene- can be selected from methylene, ethylene, propylene, butylene, pentylene and hexylene, any of which is optionally substituted.

[0112] "Alkoxy" refers to a group of the formula -O-alkyl bonded through an oxygen atom, where the alkyl is an alkyl chain as defined above.

[0113] "Alkenyl" refers to a straight-chain or branched-chain hydrocarbon chain group consisting only of carbon and hydrogen atoms, containing at least one carbon-carbon double bond, and preferably having from two to twelve carbon atoms (i.e., C2-C 12(alkenyl). In certain embodiments, the alkenyl contains two to eight carbon atoms (i.e., C2-C8 alkenyl). In certain embodiments, the alkenyl contains two to six carbon atoms (i.e., C2-C6 alkenyl). In other embodiments, the alkenyl contains two to four carbon atoms (i.e., C2-C4 alkenyl). The alkenyl is attached to the rest of the molecule by a single bond, such as ethenyl (i.e., vinyl), prop-1-enyl (i.e., allyl), but-1-enyl, pent-1-enyl, pent-1,4-dienyl, etc.

[0114] "Alkynyl" refers to a straight-chain or branched-chain hydrocarbon chain group consisting only of carbon and hydrogen atoms, containing at least one carbon-carbon triple bond, and preferably having two to twelve carbon atoms (i.e., C2-C 12 alkynyl). In certain embodiments, the alkynyl contains two to eight carbon atoms (i.e., C2-C8 alkynyl). In other embodiments, the alkynyl contains two to six carbon atoms (i.e., C2-C6 alkynyl). In other embodiments, the alkynyl contains two to four carbon atoms (i.e., C2-C4 alkynyl). The alkynyl is attached to the rest of the molecule by a single bond, such as ethynyl, propynyl, butynyl, pentynyl, hexynyl, etc.

[0115] The term "C x-y alkenyl" and "C x-y alkynyl" refer to substituted or unsubstituted unsaturated aliphatic groups, the length and possible substitutions of which are similar to those of the above-mentioned alkyl groups, but containing at least one double bond or triple bond respectively. The term -C x-y alkenylene- refers to a substituted or unsubstituted alkenylene chain, where there are x to y carbons in the alkenylene chain. For example, -C 2-6 alkenylene- can be selected from vinylene, propenylene, butenylene, pentenylene, and hexenylene, any of which is optionally substituted. The alkenylene chain can have one double bond or more than one double bond in the alkenylene chain. The term -C x-y alkynylene- refers to a substituted or unsubstituted alkynylene chain with x to y carbons in the alkynylene chain. For example, -C 2-6 alkynylene- can be selected from ethynylene, propynylene, butynylene, pentynylene, and hexynylene, any of which is optionally substituted. The alkynylene chain can have one triple bond or more than one triple bond in the alkynylene chain.

[0116] "Alkylene" or "alkylene chain" refers to a straight or branched divalent hydrocarbon chain that attaches the remainder of the molecule to a radical group consisting only of carbon and hydrogen, contains no unsaturation, and preferably has one to twelve carbon atoms, such as methylene, ethylene, propylene, n-butylene, etc. The alkylene chain is attached to the remainder of the molecule by a single bond and to the radical group by a single bond. The attachment points of the alkylene chain to the remainder of the molecule and to the radical group can be through any two carbons in the chain. In certain embodiments, the alkylene contains one to ten carbon atoms (i.e., C1-C 10 alkylene). In certain embodiments, the alkylene contains one to eight carbon atoms (i.e., C1-C8 alkylene). In other embodiments, the alkylene contains one to five carbon atoms (i.e., C 1- C5 alkylene). In other embodiments, the alkylene contains one to four carbon atoms (i.e., C1-C4 alkylene). In other embodiments, the alkylene contains one to three carbon atoms (i.e., C1-C3 alkylene). In other embodiments, the alkylene contains one to two carbon atoms (i.e., C1-C2 alkylene). In other embodiments, the alkylene contains one carbon atom (i.e., C1 alkylene). In other embodiments, the alkylene contains five to eight carbon atoms (i.e., C5-C8 alkylene). In other embodiments, the alkylene contains two to five carbon atoms (i.e., C2-C5 alkylene). In other embodiments, the alkylene contains three to five carbon atoms (i.e., C3-C5 alkylene).

[0117] "Alkenylene" or "alkenylene chain" refers to a straight or branched divalent hydrocarbon chain that attaches the remainder of the molecule to a radical group consisting only of carbon and hydrogen, contains at least one carbon-carbon double bond, and preferably has two to twelve carbon atoms. The alkenylene chain is attached to the remainder of the molecule by a single bond and to the radical group by a single bond. The attachment points of the alkenylene chain to the remainder of the molecule and to the radical group can be through any two carbon atoms in the chain. In certain embodiments, the alkenylene contains two to ten carbon atoms (i.e., C2-C 10 alkenylene). In certain embodiments, the alkenylene contains two to eight carbon atoms (i.e., C2-C8 alkenylene). In other embodiments, the alkenylene contains two to five carbon atoms (i.e., C2-C5 alkenylene). In other embodiments, the alkenylene contains two to four carbon atoms (i.e., C2-C4 alkenylene). In other embodiments, the alkenylene contains two to three carbon atoms (i.e., C2-C3 alkenylene). In other embodiments, the alkenylene contains two carbon atoms (i.e., C2 alkenylene). In other embodiments, the alkenylene contains five to eight carbon atoms (i.e., C5-C8 alkenylene). In other embodiments, the alkenylene contains three to five carbon atoms (i.e., C3-C5 alkenylene).

[0118] "Alkynylene" or "alkynylene chain" refers to a straight or branched divalent hydrocarbon chain that attaches the remainder of the molecule to a radical group consisting only of carbon and hydrogen, contains at least one carbon-carbon triple bond, and preferably has two to twelve carbon atoms. The alkynylene chain is attached to the remainder of the molecule by a single bond and to the radical group by a single bond. The attachment points of the alkynylene chain to the remainder of the molecule and to the radical group can be through any two carbon atoms in the chain. In certain embodiments, the alkynylene contains two to ten carbon atoms (i.e., C2-C 10 alkynylene). In certain embodiments, the alkynylene contains two to eight carbon atoms (i.e., C2-C8 alkynylene). In other embodiments, the alkynylene contains two to five carbon atoms (i.e., C2-C5 alkynylene). In other embodiments, the alkynylene contains two to four carbon atoms (i.e., C2-C4 alkynylene). In other embodiments, the alkynylene contains two to three carbon atoms (i.e., C2-C3 alkynylene). In other embodiments, the alkynylene contains two carbon atoms (i.e., C2 alkynylene). In other embodiments, the alkynylene contains five to eight carbon atoms (i.e., C5-C8 alkynylene). In other embodiments, the alkynylene contains three to five carbon atoms (i.e., C3-C5 alkynylene).

[0119] "Aryl" refers to a radical obtained by removing a hydrogen atom from a ring carbon atom of an aromatic monocyclic or aromatic polycyclic hydrocarbon ring system. The aromatic monocyclic or aromatic polycyclic hydrocarbon ring system contains only hydrogen and carbon, and has 5 to 18 carbon atoms, where at least one ring in the ring system is aromatic, i.e., according to Hückel's theory, it contains a cyclic, delocalized (4n + 2)π-electron system. Ring systems from which aryl is derived include, but are not limited to, groups such as benzene, fluorene, indane, indene, tetrahydronaphthalene, and naphthalene.

[0120] "Aralkyl" refers to a radical of the formula -R c -aryl, where R c is an alkylene chain as defined above, such as methylene, ethylene, etc.

[0121] "Arenyl" refers to a radical of the formula -R d -aryl, where R d is an alkenylene chain as defined above. "Arylalkynyl" refers to a radical of the formula -R e -aryl, where R e is an alkynylene chain as defined above.

[0122] "Carbocyclic ring" means a saturated ring, unsaturated ring or aromatic ring, wherein each atom of the ring is carbon. The carbocyclic ring can include monocyclic rings having 3 to 10 members, bicyclic rings having 6 to 12 members and bridged rings having 6 to 12 members. Each ring of the bicyclic carbocyclic ring can be selected from a saturated ring, an unsaturated ring and an aromatic ring. An aromatic ring (e.g., phenyl) can be fused with a saturated ring or an unsaturated ring, such as cyclohexane, cyclopentane or cyclohexene. The definition of the carbocyclic ring includes any combination of saturated rings, unsaturated rings and aromatic rings (as long as the valence allows). Exemplary carbocyclic rings include cyclopentyl, cyclohexyl, cyclohexenyl, adamantyl, phenyl, indanyl and naphthyl. The bicyclic carbocyclic ring can be a fused, bridged or spiro ring system. In some cases, the spiro carbocyclic ring has at least two molecular rings, wherein there is only one common atom.

[0123] "Carbocyclene" means a divalent carbocyclic ring that attaches the remainder of the molecule to a radical group.

[0124] The term "unsaturated carbocyclic ring" means a carbocyclic ring having at least one degree of unsaturation and does not contain an aromatic carbocyclic ring. Examples of unsaturated carbocyclic rings include cyclohexadiene, cyclohexene and cyclopentene.

[0125] "Cycloalkyl" means a fully saturated monocyclic or polycyclic hydrocarbon group consisting only of carbon and hydrogen atoms, which includes fused ring or bridged ring systems and preferably has three to twelve carbon atoms. In certain embodiments, the cycloalkyl contains three to ten carbon atoms. In other embodiments, the cycloalkyl contains five to seven carbon atoms. The cycloalkyl can be attached to the remainder of the molecule by a single bond. Examples of monocyclic cycloalkyls include, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl. Examples of polycyclic cycloalkyls include, for example, adamantyl, norbornyl (i.e., bicyclo[2.2.1]heptyl), norbornenyl, decahydronaphthyl, 7,7-dimethylbicyclo[2.2.1]heptyl, etc.

[0126] "Cycloenyl" means an unsaturated non-aromatic monocyclic or polycyclic hydrocarbon group consisting only of carbon and hydrogen atoms, which includes fused ring or bridged ring systems, preferably has three to twelve carbon atoms and contains at least one double bond. In certain embodiments, the cycloenyl contains three to ten carbon atoms. In other embodiments, the cycloenyl contains five to seven carbon atoms. The cycloenyl can be attached to the remainder of the molecule by a single bond. Examples of monocyclic cycloenyls include, for example, cyclopentenyl, cyclohexenyl, cycloheptenyl and cyclooctenyl.

[0127] "Cycloalkylalkyl" means a radical of the formula -R c -cycloalkyl, wherein R c is an alkylene chain as described above.

[0128] "Cycloalkylalkoxy" means a radical bonded through an oxygen atom of the formula -O-R c -cycloalkyl, wherein Rc is the alkylene chain as described above.

[0129] "Halogenated" or "halogen" refers to halogen substituents such as bromine, chlorine, fluorine, and iodine substituents.

[0130] As used herein, the term "haloalkyl" or "haloalkane" refers to an alkyl radical as defined above that is substituted with one or more halogen groups, such as trifluoromethyl, dichloromethyl, bromomethyl, 2,2,2-trifluoroethyl, 1-fluoromethyl-2-fluoroethyl, etc. In some embodiments, the alkyl portion of the fluoroalkyl radical is optionally further substituted. Examples of halogen-substituted alkanes ("haloalkanes") include halomethanes (e.g., chloromethane, bromomethane, fluoromethane, iodomethane), dihalomethanes, and trihalomethanes (e.g., trichloromethane, tribromomethane, trifluoromethane, triiodomethane), 1-haloethanes, 2-haloethanes, 1,2-dihaloethanes, 1-halopropanes, 2-halopropanes, 3-halopropanes, 1,2-dihalopropanes, 1,3-dihalopropanes, 2,3-dihalopropanes, 1,2,3-trihalopropanes, and any other suitable combination of an alkane (or substituted alkane) and a halogen (e.g., chlorine, bromine, fluorine, iodine, etc.). When an alkyl group is substituted with more than one halogen group, each halogen can be independently selected, e.g., 1-chloro,2-fluoroethane.

[0131] "Fluoroalkyl" refers to an alkyl radical as defined above that is substituted with one or more fluorine groups. For example, trifluoromethyl, difluoromethyl, fluoromethyl, 2,2,2-trifluoroethyl, 1-fluoromethyl-2-fluoroethyl, etc.

[0132] "Aminoalkyl" refers to an alkyl radical as defined above that is substituted with one or more amine radicals, such as propan-2-amine, butane-1,2-diamine, pentane-1,2,4-triamine, etc.

[0133] "Hydroxyalkyl" refers to an alkyl radical as defined above that is substituted with one or more hydroxy radicals, such as propan-1-ol, butane-1,4-diol, pentane-1,2,4-triol, etc.

[0134] "Alkoxyalkyl" refers to an alkyl radical as defined above that is substituted with one or more alkoxy radicals, such as methoxymethane, 1,3-dimethoxybutane, 1-methoxypropane, 2-ethoxypentane, etc.

[0135] "Cyanoalkyl" as used herein refers to an alkyl radical as defined above that is substituted with one or more cyano radicals, such as acetonitrile, 2-ethyl-3-methylbutanedinitrile, butanenitrile, etc.

[0136] "Heterocycle" refers to a saturated, unsaturated, or aromatic ring containing one or more heteroatoms. Exemplary heteroatoms include N, O, Si, P, B, and S atoms. Heterocycles include 3- to 10-membered monocycles, 6- to 12-membered bicyclic rings, and 6- to 12-membered bridged rings. Each ring of a bicyclic heterocycle can be selected from saturated, unsaturated, and aromatic rings. Bicyclic heterocycles can be fused, bridged, or spiro ring systems. In some cases, a spiro heterocycle has at least two molecular rings with only one common atom. A spiro heterocycle includes at least one heteroatom.

[0137] "Heterocyclene" refers to a divalent heterocycle that attaches the remainder of the molecule to a radical group.

[0138] "Heteroaryl" or "aromatic heterocycle" refers to a group derived from a heteroaromatic ring group that contains from one to eleven carbon atoms and at least one heteroatom, where each heteroatom can be selected from N, O, and S. As used herein, a heteroaromatic ring can be selected from monocyclic or bicyclic and fused or bridged ring systems, where at least one ring in the ring system is aromatic, i.e., it contains a cyclic, delocalized (4n + 2)π - electron system according to Hückel's theory. The heteroatoms in a heteroaryl radical can optionally be oxidized. One or more nitrogen atoms (if present) can optionally be quaternized. A heteroaryl can be attached to the remainder of the molecule through any atom of the heteroaryl (where the valence permits), such as a carbon atom or a nitrogen atom of the heteroaryl. Examples of heteroaryls include, but are not limited to, pyridine, pyrimidine, oxazole, furan, pyran, thiophene, isoxazole, benzimidazole, benzothiazole, and imidazopyridine.

[0139] "X-membered heteroaryl" is the number of atoms within the ring, i.e., X. For example, a 5-membered heteroaromatic ring or 5-membered aromatic heterocycle has 5 atoms within the ring, such as triazole, oxazole, thiophene, etc.

[0140] The term "unsaturated heterocycle" refers to a heterocycle having at least one degree of unsaturation and not containing an aromatic heterocycle. Examples of unsaturated heterocycles include pyrroline, dihydrofuran, oxazoline, pyrazoline, and dihydropyridine. Heterocycles can optionally be substituted with one or more substituents, such as those described herein.

[0141] The term "substituted" refers to a moiety having a substituent that replaces a hydrogen on one or more carbons or a replaceable heteroatom (e.g., NH of the structure). It should be understood that "substituted" or "substituted with" includes the implicit limitation that such substitution is in accordance with the allowed valences of the atom being substituted and the substituent and that the substitution results in a stable compound, i.e., a compound that does not spontaneously undergo transformation such as by rearrangement, cyclization, elimination, etc. In certain embodiments, substituted refers to a moiety having a substituent that replaces two hydrogens on the same carbon atom, such as replacing two hydrogens on a single carbon with an oxo, imino, or thio group.

[0142] As used herein, the term "substituted" is intended to include all permissible substituents of an organic compound. In a broad aspect, permissible substituents include acyclic and cyclic, branched and unbranched, carbocyclic and heterocyclic, aromatic and non-aromatic substituents of the organic compound. For suitable organic compounds, the permissible substituents can be one or more and can be the same or different. For the purposes of the present disclosure, heteroatoms (such as nitrogen) can have hydrogen substituents and / or any permissible substituents of the organic compounds described herein, which satisfy the valence of the heteroatom. In some embodiments, the substituents can include any of the substituents described herein, for example: halogen, hydroxy, oxo (═O), thioxo (═S), cyano (—CN), nitro (—NO2), imino (═NH), oxime (═N—OH), hydrazino (═N—NH2), -R b -OR a 、-R b -OC(O)-R a 、-R b -OC(O)-OR a 、-R b -OC(O)-N(R a )2、-R b -N(R a )2、-R b -C(O)R a 、-R b -C(O)OR a 、-R b -C(O)N(R a )2、-R b -O-R c -C(O)N((R a )2、-R b -N(R a )C(O)OR a 、-R b -N(R a )C(O)R a 、-R b -N(R a )S(O) t R a (where t is 1 or 2), -R b -S(O) t R a (where t is 1 or 2), -R b -S(O) t OR a (where t is 1 or 2) and -R b -S(O) t N(R a)2 (where t is 1 or 2); and alkyl, alkenyl, alkynyl, aryl, aralkyl, aralkenyl, aralkynyl, cycloalkyl, cycloalkylalkyl, and heterocycle, any of which may optionally be substituted with: alkyl, alkenyl, alkynyl, halogen, haloalkyl, haloalkenyl, haloalkynyl, oxo(=O), thioxo(=S), cyano(-CN), nitro(-NO2), imino(=NH), oximino(=N-OH), hydrazino(=N-NH2), -R b -OR a 、-R b -OC(O)-R a 、-R b -OC(-O)-OR a -、-R b -OC(O)-N(R a )2、-R b -N(R a )2、-R b -C(-O)R a 、-R b -C(O)OR a 、-R b -C(O)N(R a )2、-R b -OR c -C(O)N(R a )2、-R b -N(R a )C(O)OR a 、-R b -N(R a )C(O)R a 、-R b -N(R a )S(O) t R a (where t is 1 or 2)、-R b -S(O) t R a (where t is 1 or 2)、-R b -S(O) t OR a (where t is 1 or 2) and R b -S(O) t N(R a )2 (where t is 1 or 2); where each R a is independently selected from hydrogen, alkyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl, heterocycloalkyl, heterocycloalkylalkyl, heteroaryl, or heteroarylalkyl, where each R aOptionally, when the valence state permits, it can be substituted by any of the following: alkyl, alkenyl, alkynyl, halogen, haloalkyl, haloalkenyl, haloalkynyl, oxo(=O), thioxo(=S), cyano(-CN), nitro(-NO2), imino(=N-H), oxime(=N-OH), hydrazine(=N-NH2), -R b -OR a 、-R b -OC(O)-R a 、-R b -OC(O)-OR a 、-R b -OC(O)-N(R a )2、-R b -N(R a )2、-R b -C(O)R a 、-R b -C(O)OR a 、-R b -C(O)N(R a )2、-R b -O-R c -C(O)N(R a )2、-R b -N(R a )C(O)OR a 、-R b -N(R a )C(O)R a 、-R b -N(R a )S(O) t R a (where t is 1 or 2), -R b -S(O) t R a (where t is 1 or 2), -R b -S(O) t OR a (where t is 1 or 2) and -R b -S(O) t N(R a )2(where t is 1 or 2); and where each R b is independently selected from a direct bond or a straight-chain or branched-chain alkylene, alkenylene or alkynylene chain, and each R c is a straight-chain or branched-chain alkylene, alkenylene or alkynylene chain.

[0143] As used in this specification and the claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

[0144] The terms "salt" or "pharmaceutically acceptable salt" refer to salts derived from a variety of organic and inorganic counterions well known in the art. Pharmaceutically acceptable acid addition salts can be formed with inorganic acids and organic acids. Inorganic acids from which salts can be derived include, for example, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like. Organic acids from which salts can be derived include, for example, acetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid, maleic acid, malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, salicylic acid, and the like. Pharmaceutically acceptable base addition salts can be formed with inorganic bases and organic bases. Inorganic bases from which salts can be derived include, for example, sodium, potassium, lithium, ammonium, calcium, magnesium, iron, zinc, copper, manganese, aluminum, and the like. Organic bases from which salts can be derived include, for example, primary, secondary, and tertiary amines, substituted amines (including naturally occurring substituted amines), cyclic amines, basic ion exchange resins, and the like, specifically such as isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, and ethanolamine. In some embodiments, the pharmaceutically acceptable base addition salts are selected from ammonium salts, potassium salts, sodium salts, calcium salts, and magnesium salts.

[0145] As used herein, the phrases "parenteral administration" and "administered parenterally" mean modes of administration other than enteral and topical administration, typically by injection, and include, but are not limited to, intravenous, intramuscular, intraarterial, intrathecal, intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal, intratracheal, subcutaneous, subepidermal, intraarticular, subcapsular, subarachnoid, intraspinal, and intrasternal injection and infusion.

[0146] The phrase "pharmaceutically acceptable" as used herein refers to those compounds, materials, compositions, and / or dosage forms that, within the scope of reasonable medical judgment, are suitable for contact with human and animal tissues without excessive toxicity, irritation, allergic response, or other problems or complications, commensurate with a reasonable benefit / risk ratio.

[0147] As used herein, the phrases "pharmaceutically acceptable excipient" or "pharmaceutically acceptable carrier" mean a pharmaceutically acceptable material, composition, or vehicle, such as a liquid or solid filler, diluent, excipient, solvent, or encapsulating material. Each carrier must be "acceptable" in the sense of being compatible with the other ingredients of the formulation and not injurious to the patient. Some examples of materials that can be used as pharmaceutically acceptable carriers include: (1) sugars, such as lactose, glucose, and sucrose; (2) starches, such as corn starch and potato starch; (3) cellulose and its derivatives, such as sodium carboxymethyl cellulose, ethyl cellulose, and cellulose acetate; (4) powdered tragacanth; (5) malt; (6) gelatin; (7) talc; (8) excipients, such as cocoa butter and suppository waxes; (9) oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil, and soybean oil; (10) glycols, such as propylene glycol; (11) polyols, such as glycerin, sorbitol, mannitol, and polyethylene glycol; (12) esters, such as ethyl oleate and ethyl laurate; (13) agar; (14) buffering agents, such as magnesium hydroxide and aluminum hydroxide; (15) alginic acid; (16) pyrogen-free water; (17) isotonic saline; (18) Ringer's solution; (19) ethanol; (20) phosphate buffer solutions; and (21) other non-toxic compatible substances employed in pharmaceutical formulations.

[0148] In certain embodiments, the terms "prevent" or "preventing," as related to a disease or disorder, can refer to a compound that reduces the occurrence of a disorder or condition in a treated sample relative to an untreated control sample, or delays the onset or reduces the severity of one or more symptoms of a disorder or condition relative to an untreated control sample.

[0149] As used herein, the term "treat" can include alleviating, reducing, or ameliorating symptoms of a disease or disorder, preventing other symptoms, improving or preventing the underlying cause of symptoms, inhibiting a disease or disorder, e.g., arresting the development of a disease or disorder, alleviating a disease or disorder, causing a disease or disorder to regress, alleviating a condition caused by a disease or disorder, or prophylactically and / or therapeutically halting the symptoms of a disease or disorder.

[0150] The term "ligand" generally refers to a macromolecular compound that is capable of recognizing and binding to an antigen or receptor associated with a target cell. Ligands can be used to deliver a drug to a population of target cells to which the ligand binds, including but not limited to protein hormones, lectins, growth factors, antibodies, or other substances that can bind to cell, receptor, and / or antigen molecules. A ligand can be an antibody. A ligand can be an antigen-binding fragment. A ligand can be a targeting moiety.

[0151] The term "targeting moiety" refers to a structure that has a selective affinity for a target molecule relative to other non-target molecules. The targeting moiety binds to the target molecule. The targeting moiety can include, for example, an antibody, a peptide, a ligand, a receptor, or a binding portion thereof. The target biomolecule can be a biological receptor or other structure of a cell, such as a tumor antigen.

[0152] The term "linker" refers to a chemical moiety that is capable of combining two different chemical moieties with each other. The linker can include a spacer and an amino acid. The linker can be a cleavable linker that facilitates the release of the compounds described herein. The linker can be used to form a covalent bond with a ligand (such as an antibody).

[0153] The term "antibody" means a whole antibody and any antigen-binding fragment thereof (i.e., "antigen-binding portion") or single-chain variant. A whole antibody is a protein that contains at least two heavy chains (H) and two light chains (L), which are interconnected by disulfide bonds. Each heavy chain contains a heavy-chain variable region (VH) and a heavy-chain constant region, which contains three domains: CH1, CH2, and CH3. Each light chain contains a light-chain variable region (VL or Vk) and a light-chain constant region, which contains one domain CL. The VH and VL regions can be further subdivided into hypervariable regions, called complementarity-determining regions (CDRs), which are interspersed with more conserved framework regions (FRs). Each VH and VL contains three CDRs and four FRs, which are arranged in the following order from the amino terminus to the carboxy terminus: FR1, CDR1, FR2, CDR2, FR3, CDR3, and FR4. The variable region contains a binding domain that interacts with an antigen. The constant region can mediate the binding of the antibody to host tissues or factors, including various cells of the immune system (such as effector cells) and the first component of the classical complement system (Clq).

[0154] If the KD of an antibody binding to antigen X is 5×10 -8 M or lower, more preferably 1×10 -8 M or lower, more preferably 6×10 -9 M or lower, more preferably 3×10 -9 M or lower, even more preferably 2×10 -9 M or lower, then the antibody is said to "specifically bind" to antigen X. The antibody can be a chimeric antibody, a humanized antibody, or preferably a human antibody. The heavy-chain constant region can be engineered to affect the type or degree of glycosylation, extend the antibody half-life, enhance or reduce the interaction with effector cells or the complement system, or modulate some other property. The engineering can be accomplished by replacing, adding, or deleting one or more amino acids or by replacing a domain with a domain from another immunoglobulin type or a combination of the foregoing.

[0155] The terms "antigen-binding fragment" and "antigen-binding portion" of an antibody (or simply "antibody portion" or "antibody fragment") mean one or more fragments of an antibody that retain the ability to specifically bind to an antigen. It has been demonstrated that the antigen-binding function of an antibody can be performed by fragments of a full-length antibody, such as (i) Fab fragment, a monovalent fragment consisting of the VL, VH, CL, and CH1 domains; (ii) F(ab')2 fragment, a divalent fragment consisting of two Fab fragments linked by a disulfide bridge at the hinge region;

[0156] (iii) Fab' fragment, which is essentially a Fab with a part of the hinge region (see, for example, Abbas et al., Cellular and Molecular Immunology, 6th Edition, Saunders Elsevier 2007); (iv) Fd fragment consisting of the VH and CH1 domains; (v) Fv fragment consisting of the VL and VH domains of a single arm of an antibody; (vi) dAb fragment (Ward et al., (1989) Nature 341:544-546), which consists of the VH domain; (vii) isolated complementarity-determining region (CDR); and (viii) nanobody, a heavy-chain variable region containing a single variable domain and two constant domains. Preferred antigen-binding fragments are Fab, F(ab')2, Fab', Fv, and Fd fragments. In addition, although the two domains VL and VH of the Fv fragment are encoded by different genes, they can be joined by recombinant methods via a synthetic linker so that they can be made into a single protein chain, in which the VL and VH regions pair to form a monovalent molecule (called single-chain Fv or scFv); see, for example, Bird et al. (1988) Science 242:423-426; and Huston et al. (1988) Proc. Natl. Acad. Sci. USA 85:5879-5883). Such single-chain antibodies are also encompassed within the term "antigen-binding portion" of an antibody. Linker

[0157] The term "isolated antibody" means an antibody that is substantially free of other antibodies having different antigen specificities (e.g., an isolated antibody that specifically binds to antigen X is substantially free of antibodies that specifically bind to antigens other than antigen X). However, an isolated antibody that specifically binds to antigen X may cross-react with other antigens (such as antigen X molecules from other species). In certain embodiments, the isolated antibody specifically binds to a human antigen X and does not cross-react with other (non-human) antigen X. In addition, the isolated antibody may be substantially free of other cellular materials and / or chemicals.

[0158] The term "monoclonal antibody" or "monoclonal antibody composition" means a preparation of antibody molecules consisting of a single molecule that exhibits a single binding specificity and affinity for a particular epitope.

[0159] The term "human antibody" means an antibody having a variable region in which the framework regions and CDR regions (and constant regions, if present) are all derived from human germline immunoglobulin sequences. Human antibodies can include post-translational modifications, including natural or synthetic modifications. Human antibodies can include amino acid residues that are not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by in vitro random or site-directed mutagenesis or by in vivo somatic mutation). However, a "human antibody" does not include an antibody in which CDR sequences derived from the germline of another mammalian species, such as a mouse, are grafted onto a human framework sequence.

[0160] The term "human monoclonal antibody" means an antibody that exhibits a single binding specificity and has a variable region in which the framework regions and CDR regions are both derived from human germline immunoglobulin sequences. In one embodiment, the human monoclonal antibody is produced by a hybridoma that includes B cells obtained from a transgenic non-human animal (e.g., a transgenic mouse) having a genome that includes a human heavy chain transgene and a light chain transgene that are fused to immortalized cells.

[0161] The compounds of the present disclosure

[0162] The following is a discussion of the compounds and their salts that can be used in the methods of the present disclosure.

[0163] In one aspect, the present disclosure provides a compound of formula (I):

[0164]

[0165] or a pharmaceutically acceptable salt thereof, wherein;

[0166] R 1 is selected from -O-CH2-CH2-O- and -NH-C(O)-CH2-O-;

[0167] L is L 2 -(L 2B ) z -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ;

[0168] L 2 is selected from C 1-6 alkylene;

[0169] L 2B is selected from NR 4 C(O)O-C1-6 An alkylene-phenylene, wherein the phenylene is optionally substituted with one or more R 5 substituents;

[0170] L 3 Selected from residues comprising 1 to 7 amino acids;

[0171] L 4 Selected from optionally substituted C 1-6 alkylene, wherein the C 1-6 alkylene is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0172] L 5 Selected from (O-CH2-CH2-) q -(NR 3 ) s ;

[0173] L 6 Selected from optionally substituted C 1-6 alkylene, wherein the C 1-6 alkylene is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0174] L 7 Selected from C 5-6 carbocyclic olefins;

[0175] R 2 Selected from optionally substituted 5- to 6-membered heterocycles, wherein the 5- to 6-membered heterocycle is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0176] R 3 Selected from hydrogen and C 1-6 alkyl;

[0177] R 4 Selected from hydrogen and optionally substituted with one or more SO2C1-6 Alkyl-substituted C 1-6 alkyl;

[0178] Each R 5 is independently selected from sugar;

[0179] m is selected from 0 and 1;

[0180] n is selected from 0 and 1;

[0181] p is selected from 0 and 1;

[0182] q is selected from 0 to 8;

[0183] s is selected from 0 and 1; and

[0184] z is selected from 0 and 1.

[0185] In some embodiments, formula (I) is represented as

[0186] or a pharmaceutically acceptable salt thereof.

[0187] In some embodiments, formula (I) is represented as

[0188] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II) or formula (III), L is L 2 -L 3 -L 4 -L 5 -L 6 -L 7 -R 2 . In some cases, L is L 2 -L 3 -L 4 -L 5 -L 6 -R 2 . In some cases, L is L 2 -L 3 -L 4 -L 5 -L 6 -R 2 . In some cases, L is L 2 -L 3 -L 4 -L 7 -R 2 . In some cases, the linker is L 2 -L 3 -L 4 -R 2 . In some cases, L is L2 -L 2B -L 3 -L 4 -L 5 -R 2 。

[0189] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B) or formula (III), L 2 is selected from C 1-6 alkylene. In some cases, L 2 is C5 alkylene. In some cases, L 2 is C4 alkylene. In some cases, L 2 is C3 alkylene. In some cases, L 2 is C2 alkylene. In some cases, L 2 is C1 alkylene.

[0190] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II), formula (III) or formula (III-A), z is 1. In some cases, L 2B is selected from NR 4 C(O)O-C 1-6 alkylene-phenyl, wherein the phenyl is optionally substituted by one R 5 substituent. In some cases, L 2B is selected from NR 4 C(O)O-C 1-2 alkylene-phenyl, wherein the phenyl is optionally substituted by one R 5 substituent. In some cases, L 2B is selected from NR 4 C(O)O-C1 alkylene-phenyl, wherein the phenyl is optionally substituted by one R 5 substituent. In some cases, L 2B is In some cases, L 2B is In some cases, L 2B is In some cases, L 2B is In some cases, each R 5 is independently selected from sugars. In some cases, the sugar is selected from monosaccharides and disaccharides. In some cases, the sugar is selected from monosaccharides. In some cases, the sugar is selected from fructose, galactose, glucose, glucuronic acid, maltose, sucrose and sucrose. In some cases, the sugar is glucuronic acid. In some cases, R 5 is In some cases, R 5 is In some cases, z is 0. In some cases, R 4 is selected from hydrogen. In some cases, R 4 is selected from C 1-6 alkyl optionally substituted by one SO2C 1-6 alkyl. In some cases, R 4 is selected from C 1-6 alkyl substituted by one SO2C 1-6 alkyl. In some cases, R 4 is selected from C 1-6 alkyl substituted by one SO2 methyl. In some cases, R 4 is

[0191] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II), formula (III) or formula (III-A), L 3 is selected from residues comprising from 1 to 7 amino acids. In some cases, L 3 is selected from residues comprising from 1 to 5 amino acids. In some cases, L 3 is selected from residues comprising from 1 to 4 amino acids. In some cases, L 3 is selected from residues comprising from 1 to 3 amino acids. In some cases, L 3 is selected from residues comprising from 1 to 2 amino acids. In some cases, L 3 is selected from residues comprising from 2 to 4 amino acids. In some cases, L 3 is selected from residues comprising 1 amino acid. In some cases, L 3 is selected from residues comprising 2 amino acids. In some cases, L 3 is selected from residues comprising 3 amino acids. In some cases,

[0192] L 3 is selected from residues comprising 4 amino acids. In some cases, L 3 is selected from residues comprising 5 amino acids. In some cases, L 3 is selected from residues comprising 6 amino acids. In some cases, L 3 is selected from residues comprising 7 amino acids.

[0193] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II), formula (III) or formula (III-A), L 3 is selected from residues comprising natural and unnatural amino acids.

[0194] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II), formula (III) or formula (III-A), L 3 is selected from residues comprising natural amino acids. In some cases, L 3 is selected from residues comprising α-amino acids. In some cases, L 3 is selected from residues comprising β-amino acids.

[0195] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II), formula (III) or formula (III-A), the amino acid is a non-natural amino acid.

[0196] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II), formula (III) or formula (III-A), L 3 is selected from alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, citrulline and β-alanine. In some cases, L 3 is selected from alanine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, isoleucine, leucine, lysine, phenylalanine, serine, valine, citrulline, sarcosine and β-alanine. In some cases, L 3 is selected from alanine, glycine, lysine, phenylalanine, serine, valine, citrulline, sarcosine and β-alanine. In some cases, L 3 is selected from alanine, glycine, phenylalanine, valine, citrulline and β-alanine. In some cases, L 3 is selected from alanine, valine and citrulline. In some cases, L 3 is selected from glycine and phenylalanine. In some cases, L 3 is selected from glycine, phenylalanine and sarcosine.

[0197] In some cases, L 3 is selected from sarcosine.

[0198] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II), formula (III) or formula (III-A), L 3 comprises 4 amino acids. In some cases, L 3 comprises 2 amino acids. In some cases, L 3 comprises 1 amino acid. In some cases, L 3comprises at least two different amino acids. In some cases, L 3 is In some cases, L 3 is

[0199] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II), formula (III) or formula (III-A), L 4 is selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl. In some cases, L 4 is selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted by one or more substituents independently selected from -OH, -NH2 and oxo. In some cases, L 4 is selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted by oxo. In some cases, L 4 is selected from -C(O)-(CH2)2- and -C(O)-(CH2)5-. In some cases, L 4 is -C(O)-(CH2)2-. In some cases, L 4 is -C(O)-(CH2)3-. In some cases, L 4 is -C(O)-(CH2)4-. In some cases, L 4 is -C(O)-(CH2)5-. In some cases, L 4 is selected from

[0200] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II), formula (III) or formula (III-A), L 5 is selected from -(O-CH2-CH2-) q -(NR 3 ) s -; wherein q is selected from 0 to 8; and s is selected from 0 and 1. In some cases, L 5 is selected from -(O-CH2-CH2-) q -(NR 3 ) s-; wherein q is selected from 0 to 8; and s is 0. In some cases, L 5 is selected from -(O-CH2-CH2-) q -(NR 3 ) s -; wherein q is selected from 0 to 8; and s is 1. In some cases, q is 1. In some cases, q is 2. In some cases, q is 3. In some cases, q is 4. In some cases, q is 5. In some cases, q is 6. In some cases, L 5 is -(O-CH2-CH2-)2-NH-. In some cases, L 5 is -(O-CH2-CH2-)3-NH-. In some cases, L 5 is -(O-CH2-CH2-)4-NH-. In some cases, L 5 is -(O-CH2-CH2-)5-NH-. In some cases, L 5 is -(O-CH2-CH2-)6-NH-. In some cases, L 5 is -(O-CH2-CH2-)7-NH-. In some cases, L 5 is -(O-CH2-CH2-)8-NH-. In some cases, L 5 is selected from -(O-CH2-CH2-) 1-8 . In some cases, s is 0. In some cases, s is 1.

[0201] In some embodiments, for the compounds or salts of formula (I), formula (I-A), formula (I-B), formula (II), formula (III) or formula (III-A), L 6 is selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl. In some cases, L 6 is selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted with one or more substituents independently selected from -OH, -NH2 and oxo. In some cases, L 6 is selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted with oxo. In some cases, L 6Selected from -C(O)-(CH2)2- and -C(O)-(CH2)5-. In some cases, L 6 is -C(O)-(CH2)2-. In some cases, L 6 is -C(O)-(CH2)3-. In some cases, L 6 is -C(O)-(CH2)4-. In some cases, L 6 is -C(O)-(CH2)5-. In some cases, L 6 Selected from

[0202] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II), formula (III) or formula (III-A), L 7 is selected from C 5-6 carbocyclic ring. In some cases, L 7 is selected from C 5-6 carbocyclic ring olefin. In some cases, L 7 is selected from C6 carbocyclic ring. In some cases, L 7 is selected from C6 carbocyclic ring olefin. In some cases, L 7 is phenylene. In some cases, L 7 is cyclohexylene. In some cases, L 7 is In some cases, L 7 is

[0203] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II) or formula (III), R 2 is selected from optionally substituted 5- to 6-membered heterocycles, wherein the 5- to 6-membered heterocycle is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl. In some cases, R 2 is selected from optionally substituted 5- to 6-membered heterocyclic olefins, wherein the 5- to 6-membered heterocyclic olefin is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl. In some cases, R 2Selected from optionally substituted 5- to 6-membered heterocycles, wherein the 5- to 6-membered heterocycle is optionally substituted with one or more substituents independently selected from oxo and halogen. In some cases, R 2 Selected from optionally substituted 5- to 6-membered heteroalkenes, wherein the 5- to 6-membered heteroalkene is optionally substituted with one or more substituents independently selected from oxo and halogen. In some cases, R 2 Selected from optionally substituted 5-membered heterocycles, wherein the 5-membered heterocycle is optionally substituted with one or more substituents independently selected from oxo. In some cases, R 2 Selected from optionally substituted 5-membered heteroalkenes, wherein the 5-membered heteroalkene is optionally substituted with one or more substituents independently selected from oxo. In some cases, the 5-membered heterocycle has at least one double bond. In some cases, the 5-membered heterocycle has one double bond. In some cases, R 2 is maleimide. In some cases, R 2 is In some cases, R 2 is wherein Lg is a ligand. In some cases, R 2 is a reactive moiety capable of forming a new bond. In some cases, R 2 is a reactive moiety capable of forming a new bond from an existing double bond.

[0204] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II), formula (III) or formula (III-A), L 2 -L 3 -L 4 -R 2 is selected from

[0205]

[0206] In some cases, L 2 -L 3 -L 4 is

[0207] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II), formula (III) or formula (III-A), L 2 -L 3 -L 4 is In some cases, L 2 -L 3 is

[0208] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II) or formula (III), L 2 -L 3 -L 4 -L 5 -L 6 -L 7 -R 2 is In some cases, L 2 -L 3 -L 4 -L 5 -L 6 -L 7 is In some cases, L 2 -L 3 -L 4 -L 5 -L 6 is In some cases, L 2 -L 3 -L 4 -L 5 is In some cases, L 2 -L 3 -L 4 -L 5 is

[0212] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II) or formula (III), L 2 -L 2B -L 3 -L 4 -R 2 is In some cases, L 2 -L 2B -L 3 -L 4 is In some cases, L 2 -L 2B -L 3 is In some cases, L 2 -L 2B is In some cases, L 2B is

[0213] In some embodiments, for a compound or salt of formula (I), formula (I-A), formula (I-B), formula (II) or formula (III), L is

[0214] In some embodiments, Formula (I) is represented as

[0215]

[0216] or a pharmaceutically acceptable salt thereof, wherein Lg is a ligand.

[0217] In one aspect, the present disclosure provides a compound of Formula (III):

[0218]

[0219] or a pharmaceutically acceptable salt thereof, wherein;

[0220] Lg is a ligand

[0221] R 1 is selected from -O-CH2-CH2-O- and -NH-C(O)-CH2-O-;

[0222] L is L 2 -(L 2B ) z -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ;

[0223] L 2 is selected from C 1-6 alkylene;

[0224] L 3 is selected from residues comprising 1 to 7 amino acids;

[0225] L 4 is selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0226] L 5 is selected from -(O-CH2-CH2-) q -(NR 3 ) s-;

[0227] L 6 selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0228] L 7 selected from C 5-6 carbocyclic ring;

[0229] R 2 selected from optionally substituted 5- to 6-membered heterocycles, wherein the 5- to 6-membered heterocycle is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0230] R 3 selected from hydrogen and C 1-6 alkyl;

[0231] R 4 selected from optionally substituted C 1-6 alkyl substituted by one or more SO2C 1-6 alkyl;

[0232] each R 5 is independently selected from sugars;

[0233] m is selected from 0 and 1;

[0234] n is selected from 0 and 1;

[0235] p is selected from 0 and 1;

[0236] q is selected from 0 to 8;

[0237] s is selected from 0 and 1; and

[0238] z is selected from 0 and 1.

[0239] In some embodiments, formula (III) is represented as

[0240]

[0241] or a pharmaceutically acceptable salt thereof.

[0242] In one aspect, the present disclosure provides a compound of formula (IV)

[0243]

[0244] or a pharmaceutically acceptable salt thereof.

[0245] In some embodiments, for a compound or salt of formula (I), formula (I-A), or formula (I-B), R 1 is selected from -O-CH2-CH2-O-;

[0246] L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ;

[0247] L 2 is selected from C 1-6 alkylene;

[0248] L 3 is selected from residues comprising 3 to 5 amino acids;

[0249] L 4 is selected from

[0250] L 5 is selected from (O-CH2-CH2-) q -(NR 3 ) s ;

[0251] L 6 is selected from

[0252] L 7 is phenylene;

[0253] R 2 is selected from maleimide;

[0254] R 3 is selected from hydrogen and C 1-6 alkyl;

[0255] m is selected from 0 and 1;

[0256] n is selected from 0 and 1;

[0257] p is selected from 0 and 1;

[0258] q is selected from 2 to 6; and

[0259] s is selected from 0 and 1.

[0260] In some embodiments, for a compound or salt of formula (I), formula (I-A) or formula (I-B), R 1 is selected from -O-CH2-CH2-O-;

[0261] L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ;

[0262] L 2 is

[0263] L 3 is

[0264] L 4 is selected from

[0265] L 5 is m is selected from 0 and 1;

[0266] L 6 n is selected from 0 and 1;

[0267] L 7 is selected from p is selected from 0 and 1;

[0268] R 2 is

[0269] In some embodiments, for a compound or salt of formula (I), formula (I-A) or formula (I-B), R 1 is selected from -O-CH2-CH2-O-;

[0270] L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ;

[0271] L2 is

[0272] L 3 is

[0273] L 4 selected from

[0274] L 5 is m is selected from 0 and 1;

[0275] L 6 n is selected from 0 and 1;

[0276] L 7 p is selected from 0 and 1;

[0277] R 2

[0278] In some embodiments, formula (III) is represented by formula (V-A)

[0279] or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1-8. In some cases, the DAR is about 8.

[0281] In some embodiments, formula (III) is represented by formula (V-B)

[0282] or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1-8. In some cases, the DAR is about 8.

[0284] In some embodiments, formula (III) is represented by formula (V-C):

[0285] or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1-8. In some cases, the DAR is about 8.

[0287] In some embodiments, formula (III) is represented by formula (V-D)

[0288] or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1-8. In some cases, the DAR is about 8.

[0290] In some embodiments, the compounds of formula (III) are selected from:

[0291]

[0292] or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1 - 8. In some cases, the DAR is about 8.

[0293] In some embodiments, the compound of formula (III) is selected from:

[0294]

[0295] or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1 - 8. In some cases, the DAR is about 8.

[0296] In some embodiments, the compound of formula (III) is selected from:

[0297]

[0298] or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1 - 8.

[0299] In some embodiments, formula (III) or formula (IV)* includes a DAR value. In some cases, the DAR is the ratio of drug to antibody. In some cases, the DAR is the average number of drugs conjugated to a ligand (Lg). In some cases, the DAR is determined using RP - HPLC. In some cases, the DAR is determined using RP - HPLC as described in Example 17. In some cases, the DAR is at most about 16. In some cases, the DAR is about 8. In some cases, the DAR is at most about 10. In some cases, the DAR is at least about 1. In some cases, the DAR is at least about 2. In some cases, the DAR is at least about 4. In some cases, the DAR is at least about 8. In some cases, the DAR is at most about 8. In some cases, the DAR is from about 1 to about 16. In some cases, the DAR is from about 4 to about 12. In some cases, the DAR is from about 6 to about 10. In some cases, the DAR is from about 7 to about 9. In some cases, the DAR is from about 8 to about 10. In some cases, the DAR is from about 6 to about 8. In some cases, the DAR is about 8.

[0300] In some embodiments, for a compound or salt of formula (III), formula (V-A), formula (V-B), formula (V-C) or formula (V-D), the DAR is the ratio of drug to antibody. In some cases, the DAR is the average number of drugs conjugated to the ligand (Lg). In some cases, the DAR is determined using RP-HPLC. In some cases, the DAR is determined using RP-HPLC as described in Example 17. In some cases, the DAR is at most about 16. In some cases, the DAR is about 8. In some cases, the DAR is at most about 10. In some cases, the DAR is at least about 1. In some cases, the DAR is at least about 2. In some cases, the DAR is at least about 4. In some cases, the DAR is at least about 8. In some cases, the DAR is at most about 8. In some cases, the DAR is from about 1 to about 16. In some cases, the DAR is from about 4 to about 12. In some cases, the DAR is from about 6 to about 10. In some cases, the DAR is from about 7 to about 9. In some cases, the DAR is from about 8 to about 10. In some cases, the DAR is from about 6 to about 8. In some cases, the DAR is about 8.

[0301] In some embodiments, for a compound or salt of formula (I), formula (I-A) or formula (I-B), formula (III), formula (V-A), formula (V-B), formula (V-C), formula (V-D) or formula (IV)*, the ligand is selected from UC-961, PTK-7, trastuzumab, brentuximab, loncastuximab, rosopatamab, rituximab, pinatuzumab, polatuzumab and naratuximab. In some cases, the ligand is selected from trastuzumab, brentuximab, loncastuximab, rosopatamab, rituximab, pinatuzumab, polatuzumab and naratuximab. In some cases, the ligand is trastuzumab.

[0302] In one aspect, the present disclosure provides a compound represented by formula (I)*

[0303]

[0304] or a pharmaceutically acceptable salt thereof, wherein;

[0305] L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 )n -(L 7 ) p -R 2 ;

[0306] L is selected from C 2 alkylene; 1-6

[0307] L is selected from residues containing 1 to 7 amino acids; 3

[0308] L is selected from optionally substituted C 4 alkylene, wherein the C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-6 haloalkyl, -O-C 1-10 alkyl, C 1-10 alkenyl, C 2-10 alkynyl; 2-10

[0309] L is selected from (O-CH2-CH2-) 5 -(NR q ) 3 ; s

[0310] L is selected from optionally substituted C 6 alkylene, wherein the C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-6 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 1-10 alkenyl, C 2-10 alkynyl; 2-10

[0311] L is selected from C 7 carbocyclic olefins; 5-6

[0312] R is selected from optionally substituted 5- to 6-membered heterocycles, wherein the 5- to 6-membered heterocycles are optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 2 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 1-10 alkenyl, C 2-10 alkynyl; 2-10

[0313] R is selected from hydrogen and C 3 ​​​​​​​​1-6 Alkyl;

[0314] m is selected from 0 and 1;

[0315] n is selected from 0 and 1;

[0316] p is selected from 0 and 1;

[0317] q is selected from 0 to 8; and

[0318] s is selected from 0 and 1.

[0319] In some embodiments, formula (I)* is represented as

[0320]

[0321] or a pharmaceutically acceptable salt thereof.

[0322] In some embodiments, formula (I)* is represented as

[0323]

[0324] or a pharmaceutically acceptable salt thereof, wherein;

[0325] Lg is a ligand.

[0326] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)* or formula (IV)*, L is L 2 -L 3 -L 4 -L 5 -L 6 -L 7 -R 2 . In some cases, L is L 2 -L 3 -L 4 -L 5 -L 6 -R 2 . In some cases, L is L 2 -L 3 -L 4 -L 6 -R 2 . In some cases, L is L 2 -L 3 -L 6 -L 7 -R 2 . In some cases, the linker is L 2 -L 3 -L 4 -R 2 . In some cases, L is L 2 -L4 -R 2 。

[0327] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)* or formula (IV-A)*, L 2 is selected from C 1-6 alkylene. In some cases, L 2 is C5 alkylene. In some cases, L 2 is C4 alkylene. In some cases, L 2 is C3 alkylene. In some cases, L 2 is C2 alkylene. In some cases, L 2 is C1 alkylene.

[0328] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)* or formula (IV-A)*, L 3 is selected from residues comprising 1 to 7 amino acids. In some cases, L 3 is selected from residues comprising 1 to 5 amino acids. In some cases, L 3 is selected from residues comprising 1 to 4 amino acids. In some cases, L 3 is selected from residues comprising 1 to 3 amino acids. In some cases, L 3 is selected from residues comprising 1 to 2 amino acids. In some cases, L 3 is selected from residues comprising 2 to 4 amino acids. In some cases, L 3 is selected from residues comprising 1 amino acid. In some cases, L 3 is selected from residues comprising 2 amino acids. In some cases, L 3 is selected from residues comprising 3 amino acids. In some cases,

[0329] L 3 is selected from residues comprising 4 amino acids. In some cases, L 3 is selected from residues comprising 5 amino acids. In some cases, L 3 is selected from residues comprising 6 amino acids. In some cases, L 3 is selected from residues comprising 7 amino acids.

[0330] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)* or formula (IV-A)*, L 3 is selected from residues comprising natural and unnatural amino acids.

[0331] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)*, or formula (IV-A)*, L 3 is selected from residues comprising natural amino acids. In some cases, L 3 is selected from residues comprising α-amino acids. In some cases, L 3 is selected from residues comprising β-amino acids.

[0332] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)*, or formula (IV-A)*, the amino acid is a non-natural amino acid.

[0333] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)*, or formula (IV-A)*, L 3 is selected from alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, citrulline, and β-alanine. In some cases, L 3 is selected from alanine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, isoleucine, leucine, lysine, phenylalanine, serine, valine, citrulline, sarcosine, and β-alanine. In some cases, L 3 is selected from alanine, glycine, lysine, phenylalanine, serine, valine, citrulline, sarcosine, and β-alanine. In some cases, L 3 is selected from alanine, glycine, phenylalanine, valine, citrulline, and β-alanine. In some cases, L 3 is selected from alanine, valine, and citrulline. In some cases, L 3 is selected from glycine and phenylalanine. In some cases, L 3 is selected from glycine, phenylalanine, and sarcosine.

[0334] In some cases, L 3 is selected from sarcosine.

[0335] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)*, or formula (IV-A)*, L 3 comprises 4 amino acids. In some cases, L 3 comprises 2 amino acids. In some cases, L 3 comprises 1 amino acid. In some cases, L 3 comprises at least 2 different amino acids. In some cases, L 3 is

[0336]

[0337] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)* or formula (IV-A)*, L 4 is selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl. In some cases, L 4 is selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted with one or more substituents independently selected from -OH, -NH2 and oxo. In some cases, L 4 is selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted with oxo. In some cases, L 4 is selected from -C(O)-(CH2)2- and -C(O)-(CH2)5-. In some cases, L 4 is -C(O)-(CH2)2-. In some cases, L 4 is -C(O)-(CH2)3-. In some cases, L 4 is -C(O)-(CH2)4-. In some cases, L 4 is -C(O)-(CH2)5-. In some cases, L 4 is

[0338] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)* or formula (IV-A)*, L 5 is selected from -(O-CH2-CH2-) q -(NR 3 ) s -; wherein q is selected from 0 to 8; and s is selected from 0 and 1. In some cases, L 5 is selected from -(O-CH2-CH2-) q -(NR 3 ) s -; wherein q is selected from 0 to 8; and s is 0. In some cases, L 5 is selected from -(O-CH2-CH2-)q -(NR 3 ) s -; wherein, q is selected from 0 to 8; and s is 1. In some cases, q is 1. In some cases, q is 2. In some cases, q is 3. In some cases, q is 4. In some cases, q is 5. In some cases, q is 6. In some cases, L 5 is -(O-CH2-CH2-)2-NH-. In some cases, L 5 is -(O-CH2-CH2-)3-NH-. In some cases, L 5 is -(O-CH2-CH2-)4-NH-. In some cases, L 5 is -(O-CH2-CH2-)5-NH-. In some cases, L 5 is -(O-CH2-CH2-)6-NH-. In some cases, L 5 is -(O-CH2-CH2-)7-NH-. In some cases, L 5 is -(O-CH2-CH2-)8-NH-. In some cases, L 5 is selected from -(O-CH2-CH2-) 1-8 . In some cases, s is 0. In some cases, s is 1.

[0339] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)* or formula (IV-A)*, L 6 is selected from optionally substituted C 1-6 alkylene, wherein the C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl. In some cases, L 6 is selected from optionally substituted C 1-6 alkylene, wherein the C 1-6 alkylene is optionally substituted by one or more substituents independently selected from -OH, -NH2 and oxo. In some cases, L 6 is selected from optionally substituted C 1-6 alkylene, wherein the C 1-6 alkylene is optionally substituted by oxo. In some cases, L 6 is selected from -C(O)-(CH2)2- and -C(O)-(CH2)5-. In some cases, L 6is -C(O)-(CH2)2-. In some cases, L 6 is -C(O)-(CH2)3-. In some cases, L 6 is -C(O)-(CH2)4-. In some cases, L 6 is -C(O)-(CH2)5-. In some cases, L 6 is selected from

[0340] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)* or formula (IV-A)*, L 7 is selected from C 5-6 carbocyclic ring. In some cases, L 7 is selected from C6 carbocyclic ring. In some cases, L 7 is selected from C6 carbocyclic alkene. In some cases, L 7 is phenylene. In some cases, L 7 is cyclohexylene. In some cases, L 7 is In some cases, L 7 is In some cases, p is 0. In some cases, p is 1.

[0341] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)* or formula (IV)*, R 2 is selected from an optionally substituted 5- to 6-membered heterocyclic ring, wherein the 5- to 6-membered heterocyclic ring is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl. In some cases, R 2 is selected from an optionally substituted 5- to 6-membered heterocyclic alkene, wherein the 5- to 6-membered heterocyclic alkene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl. In some cases, R 2 is selected from an optionally substituted 5- to 6-membered heterocyclic ring, wherein the 5- to 6-membered heterocyclic ring is optionally substituted by one or more substituents independently selected from oxo and halogen. In some cases, R 2Selected from optionally substituted 5- to 6-membered heteroalkenes, wherein the 5- to 6-membered heteroalkene is optionally substituted with one or more substituents independently selected from oxo. In some cases, R 2 Selected from optionally substituted 5-membered heterocycles, wherein the 5-membered heterocycle is optionally substituted with one or more substituents independently selected from oxo. In some cases, the 5-membered heterocycle has at least one double bond. In some cases, the 5-membered heterocycle has one double bond. In some cases, R 2 is maleimide. In some cases, R 2 is In some cases, R 2 is In some cases, R 2 is a reactive moiety capable of forming a new bond. In some cases, R 2 is a reactive moiety capable of forming a new bond from an existing double bond.

[0342] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, or formula (IV)*, L 2 -L 3 -L 4 -R 2 is selected from

[0343] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)*, or formula (IV-A)*, in some cases, L 2 -L 3 -L 4 is

[0344]

[0345] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)*, or formula (IV-A)*, L 2 -L 3 -L 4 is In some cases, L 2 -L 3 is

[0346]

[0347] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, or formula (IV)*, L 2 -L 3 -L 4 -L 5 -L6 -L 7 -R 2 is In some cases, L 2 -L 3 -L 4 -L 5 -L 6 -L 7 is

[0350] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)*, formula (IV)* or formula (IV-A)*, L 2 -L 3 -L 4 -L 5 -L 6 is In some cases, L 2 -L 3 -L 4 -L 5 is In some cases, L 2 -L 3 -L 4 -L 5 is

[0351] In some embodiments, for a compound or salt of formula (I)*, formula (II)*, formula (III)* or formula (IV)*, L is selected from

[0352]

[0353] In one aspect, the present disclosure provides a compound of formula (IV)*:

[0354]

[0355] or a pharmaceutically acceptable salt thereof, wherein;

[0356] Lg is a ligand;

[0357] L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ;

[0358] L 2 is selected from C1-6 Alkylene;

[0359] L 3 Selected from residues containing 1 to 7 amino acids;

[0360] L 4 Selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0361] L 5 Selected from (O-CH2-CH2)- q -(NR 3 ) s ;

[0362] L 6 Selected from optionally substituted C 1-6 alkylene, wherein C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0363] L 7 Selected from C 5-6 carbocycle;

[0364] R 2 Selected from optionally substituted 5- to 6-membered heterocycles, wherein the 5- to 6-membered heterocycle is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl;

[0365] R 3 Selected from hydrogen and C 1-6 alkyl;

[0366] m is selected from 0 and 1;

[0367] n is selected from 0 and 1;

[0368] p is selected from 0 and 1;

[0369] q is selected from 0 to 8; and

[0370] s is selected from 0 and 1.

[0371] In some embodiments, formula (IV)* is represented as

[0372]

[0373] or a pharmaceutically acceptable salt thereof.

[0374] Included in the present disclosure are salts, particularly pharmaceutically acceptable salts of the compounds described herein. Compounds of the present invention having sufficient acidity, sufficient basicity, or both functional groups can react with a variety of inorganic bases, as well as inorganic and organic acids, to form salts. Alternatively, inherently charged compounds (such as compounds having a quaternary nitrogen) can form salts with suitable counterions (such as halides such as bromide, chloride, or fluoride, particularly bromide).

[0375] Chemical entities having a carbon-carbon double bond or a carbon-nitrogen double bond can exist in the Z- or E-form (or cis or trans). In addition, some chemical entities can exist in various tautomeric forms. Unless otherwise stated, the compounds described herein are also intended to include all Z-, E-, and tautomeric forms.

[0376] A "tautomer" refers to a molecule in which a proton can transfer from one atom of the molecule to another atom of the same molecule. In certain embodiments, the compounds described herein exist as tautomers. Where tautomerism can occur, there will be a chemical equilibrium between the tautomers. The exact ratio of tautomers depends on several factors, including physical state, temperature, solvent, and pH. Some examples of tautomeric equilibria include:

[0377]

[0378] In some embodiments, the compounds disclosed herein are used in different enriched isotope forms, for example, enriched in the content of 2 H, 3 H, 11 C, 13 C, and / or 14 C. In one particular embodiment, the compound is deuterated at at least one position. Such deuterated forms can be prepared by the procedures described in U.S. Patent Nos. 5,846,514 and 6,334,997. As described in U.S. Patent Nos. 5,846,514 and 6,334,997, deuteration can improve metabolic stability and / or efficacy, thereby prolonging the duration of action of the drug.

[0379] Unless otherwise indicated, the compounds described herein are intended to include compounds that differ only in the presence of one or more isotopically enriched atoms. For example, compounds having the present structure but with hydrogen replaced by deuterium or tritium, or carbon replaced by carbon enriched in 13 C or 14 C are within the scope of the present disclosure.

[0380] The compounds of the present disclosure optionally contain unnatural proportions of atomic isotopes at one or more atoms that make up such compounds. For example, the compounds can be isotopically labeled, such as with deuterium ( 2 H), tritium ( 3 H), iodine-125 ( 125 I), or carbon-14 ( 14 C). Isotopic substitution with 2 H, 11 C, 13 C, 14 C, 15 C, 12 N, 13 N, 15 N, 16 N, 16 O, 17 O, 14 F, 15 F, 16 F, 17 F, 18 F, 33 S, 34 S, 35 S, 36 S, 35 Cl, 37 Cl, 79 Br, 81 Br and 125 I is also contemplated. All isotopic variants of the compounds of the present invention, whether radioactive or not, are encompassed within the scope of the present invention.

[0381] In certain embodiments, some or all of the 1 H of the compounds disclosed herein is replaced by 2 H. Methods for synthesizing deuterated compounds are known in the art and include, but are not limited to, the following synthetic methods.

[0382] Deuterium-substituted compounds are synthesized using various methods described in the following documents: Dean, Dennis C.; editor. Recent Advances in the Synthesis and Applications of Radiolabeled Compounds for Drug Discovery and Development. [In: Curr., Pharm. Des., 2000; 6(10)] 2000, 110 pp; George W.; Varma, Rajender S. The Synthesis of Radiolabeled Compounds via Organometallic Intermediates, Tetrahedron, 1989, 45(21), 6601-21; and Evans, E. Anthony. Synthesis of Radiolabeled compounds, J. Radioanal. Chem., 1981, 64(1-2), 9-32.

[0383] Deuterated starting materials are readily available and are used in the synthetic methods described herein for the synthesis of deuterium-containing compounds. A large number of deuterated reagents and building blocks are available from chemical suppliers such as Aldrich Chemical Co.

[0384] The compounds of the present invention also include crystalline and amorphous forms of these compounds, pharmaceutically acceptable salts, and active metabolites of these compounds having the same type of activity, including, for example, polymorphs, pseudopolymorphs, solvates, hydrates, non-solvated polymorphs (including anhydrous compounds), conformational polymorphs, and amorphous forms of the compounds, and mixtures thereof.

[0385] The compounds described herein may, in some cases, exist as diastereoisomers, enantiomers or other stereoisomeric forms. If no absolute stereochemistry is specified, the compounds described herein include all diastereoisomeric, enantiomeric and epimeric forms and their appropriate mixtures. Separation of stereoisomers can be effected by chromatography or by formation of diastereoisomers and by recrystallization or chromatography or any combination thereof. (Jean Jacques, Andre Collet, Samuel H. Wilen, “Enantiomers, Racemates and Resolutions”, John Wiley And Sons, Inc., 1981, which is incorporated herein by reference for this disclosure). Stereoisomers can also be obtained by stereoselective synthesis.

[0386] The methods and compositions described herein include the use of amorphous forms as well as crystalline forms (also referred to as polymorphs). The compounds described herein may be in the form of pharmaceutically acceptable salts. In addition, in some embodiments, the active metabolites of these compounds having the same type of activity are included within the scope of the present disclosure. Further, the compounds described herein may exist in unsolvated form or in solvated form with a pharmaceutically acceptable solvent such as water, ethanol, etc. The solvated forms of the compounds described herein are also considered to be disclosed herein.

[0387] In certain embodiments, a compound or a salt of a compound may be a prodrug, for example, where a hydroxyl group in the parent compound is present as an ester or a carbonate or a carboxylic acid in the parent compound. The term “prodrug” is intended to cover compounds that are converted into the agents of the present disclosure under physiological conditions. One method for preparing a prodrug involves hydrolyzing one or more selected moieties under physiological conditions to reveal the desired molecule. In other embodiments, the prodrug is converted by the enzymatic activity of a host animal such as a particular target cell within the host animal. For example, esters or carbonates (e.g., esters of alcohols or carboxylic acids and carbonates and esters of phosphonic acids) are preferred prodrugs of the present disclosure.

[0388] Prodrug forms of the compounds described herein, wherein the prodrug is metabolized in vivo to produce a compound as shown herein are included within the scope of the claims. In some cases, some of the compounds described herein may be prodrugs of another derivative or active compound.

[0389] Prodrugs are often useful because, in some cases, they may be more readily administered than the parent drug. For example, they may be bioavailable by oral administration, while the parent is not. Prodrugs can help enhance the cellular permeability of a compound relative to the parent drug. The solubility of a prodrug in a pharmaceutical composition can also be higher than that of the parent drug. Prodrugs can be designed as reversible drug derivatives to serve as modifiers to enhance the transport of a drug to a site-specific tissue or to increase the residence of a drug within a cell.

[0390] In some embodiments, the prodrug is designed to increase the lipophilicity of the agent. In some embodiments, the prodrug is designed to increase effective water solubility. See, e.g., Fedorak et al., Am. J. Physiol., 269:G210-218 (1995); McLoed et al., Gastroenterol, 106:405-413 (1994); Hochhaus et al., Biomed. Chrom., 6:283-286 (1992); J. Larsen and H. Bundgaard, Int. J. Pharmaceutics, 37, 87 (1987); J. Larsen et al., Int. J. Pharmaceutics, 47, 103 (1988); Sinkula et al., J. Pharm. Sci., 64:181-210 (1975); T. Higuchi and V. Stella, Pro-drugs as Novel Delivery Systems, Vol. 14 of the A.C.S. Symposium Series; and Edward B. Roche, Bioreversible Carriers in Drug Design, American Pharmaceutical Association and Pergamon Press, 1987, all of which are incorporated herein by reference for such disclosures. According to another embodiment, the present disclosure provides methods of producing the compounds defined above. The compounds can be synthesized using conventional techniques. Advantageously, these compounds are conveniently synthesized from readily available starting materials.

[0391] Synthetic chemical transformations and methods useful for synthesizing the compounds described herein are known in the art, including, for example, those described in R. Larock, Comprehensive Organic Transformations (1989); T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, 2d. Ed. (1991); L. Fieser and M. Fieser, Fieserand Fieser’s Reagents for Organic Synthesis (1994); and L. Paquette, ed., Encyclopedia of Reagents for Organic Synthesis (1995).

[0392] Ligand / antibody

[0393] In some embodiments, for the compounds or salts of formula (I), formula (I-A), formula (I-B), formula (II), formula (III), formula (III-A), formula (V-A), formula (V-B), formula (V-C), formula (V-D), formula (III)*, formula (III-A), formula (IV)* or formula (IV-A)*, the ligand is selected from an antibody or an antigen-binding fragment thereof. In some cases, the ligand is selected from chimeric antibodies, humanized antibodies, and human antibodies.

[0394] In some embodiments, the ligand (e.g., an antibody) functions as a targeting moiety. By binding to the target tissue or cell where its antigen or receptor is located, the ligand directs the conjugate thereto. In some cases, when the ligand is an antibody, the compound is sometimes referred to as an antibody-drug conjugate (ADC) or an immunoconjugate. Preferably, the target tissue or cell is a cancer tissue or cell, and the antigen or receptor is a tumor-associated antigen, i.e., an antigen that is uniquely expressed or overexpressed by cancer cells compared to non-cancerous cells. In some cases, the conjugate is internalized into the target cell by endocytosis and cleavage occurs within the target cell.

[0395] In some embodiments, the antibody or an antigen-binding fragment thereof binds to an antigen selected from the group consisting of or comprising CD19, CD20, CD22, CD30, CD37, CD79b, HER2, and PSMA. In some embodiments, the antibody or an antigen-binding fragment thereof binds to HER2. In some cases, the antibody or an antigen-binding fragment thereof is selected from trastuzumab, brentuximab vedotin, loncastuximab tesirine, rosoxatumumab, rituximab, pinatuzumab vedotin, polatuzumab vedotin, and necitumumab. In some cases, the antibody is trastuzumab.

[0396] In some embodiments, the ligand is an antibody against a tumor-associated antigen, allowing for selective targeting of cancer cells. Examples of such antigens include: mesothelin, prostate-specific membrane antigen (PSMA), CD19, CD22, CD30, CD70, B7H3, B7H4 (also known as O8E), protein tyrosine kinase 7 (PTK7), glypican-3

[0397] (Glypican-3), RG1, fucosyl-GM1, CTLA-4, and CD44. The antibody can be of animal origin (e.g., murine), chimeric, humanized, or preferably human. The antibody is preferably a monoclonal antibody, especially a monoclonal human antibody. The preparation of monoclonal human antibodies against some of the above antigens is disclosed in the following: Korman et al., U.S. Patent No. 8,609,816 B2 (2013; B7H4, also known as O8E; especially antibodies 2A7, 1G11, and 2F9); Rao-Naik et al., U.S. Patent No. 8,097,703 B2 (2012; CD19; especially antibodies 5G7, 13F1, 46E8, 21D4, 21D4a, 47G4, 27F3, and 3C10); King et al., U.S. Patent No. 8,481,683 B2 (2013; CD22; especially antibodies 12C5, 19A3, 16F7, and 23C6); Keler et al., U.S. Patent No. 7,387,776 B2 (2008; CD30; especially antibodies 5F11, 2H9, and 17G1); Terrett et al., U.S. Patent No. 8,124,738 B2 (2012; CD70; especially antibodies 2H5, 10B4, 8B5, 18E7, and 69A7); Korman et al., U.S. Patent No. 6,984,720 B1 (2006; CTLA-4; especially antibodies 10D1, 4B6, and 1E2); Vistica et al., U.S. Patent No. 8,383,118 B2 (2013, fucosyl-GM1, especially antibodies 5B1, 5B1a, 7D4, 7E4, 13B8, and 18D5); Korman et al., U.S. Patent No. 8,008,449 B2 (2011; PD-1; especially antibodies 17D8, 2D3, 4H1, 5C4, 4A11, 7D3, and 5F4); Huang et al., US2009 / 0297438 A1 (2009; PSMA; especially antibodies 1C3, 2A10, 2F5, 2C6); Cardarelli et al., U.S. Patent No. 7,875,278 B2 (2011; PSMA; especially antibodies 4A3, 7F12, 8C12, 8A11, 16F9, 2A10, 2C6, 2F5, and 1C3); Terrett et al., U.S. Patent No. 8,222,375 B2 (2012; PTK7; especially antibodies 3G8, 4D5, 12C6, 12C6a, and 7C8); Terrett et al., U.S. Patent No.

[0398] 8,680,247 B2 (2014; phosphatidylinositol glycan-3; specifically antibodies 4A6, 11E7, and 16D10); Harkins et al., U.S. Patent No. 7,335,748 B2 (2008; RG1; specifically antibodies A, B, C, and D); Terrett et al., U.S. Patent No. 8,268,970 B2 (2012; mesothelin; specifically antibodies 3C10, 6A4, and 7B1); Xu et al., US2010 / 0092484 A1 (2010; CD44; specifically antibodies 14G9.B8.B4, 2D1.A3.D12, and 1A9.A6.B9); Deshpande et al., U.S. Patent No. 8,258,266 B2 (2012; IP10; specifically antibodies 1D4, 1E1, 2G1, 3C4, 6A5, 6A8, 7C10, 8F6, 10A12, 10A2S, and 13C4); Kuhne et al., U.S. Patent No. 8,450,464 B2 (2013; CXCR4; specifically antibodies F7, F9, D1, and E2); and Korman et al., U.S. Patent No. 7,943,743 B2 (2011; PD-L1; specifically antibodies 3G10, 12A4, 10A5, 5F8, 10H10, 1B12, 7H1, 11E6, 12B7, and 13G4); the disclosures of which are incorporated herein by reference.

[0399] In some embodiments, the ligand can also be an antibody fragment or an antibody mimetic, such as an affibody, a domain antibody (dAb), a nanobody, a unibody, a DARPin, an anticalin, a versabody, a duocalin, a lipocalin, or an avimer.

[0400] In some embodiments, any one of several different reactive groups on the ligand can serve as a conjugation site, including the ε-amino group in a lysine residue, a pendant carbohydrate moiety, a carboxylic acid group, a disulfide group, and a thiol group. Each type of reactive group represents a trade-off, having some advantages and some disadvantages. For a review of antibody reactive groups suitable for conjugation, see, e.g., Garnett, Adv. Drug Delivery Rev. 53 (2001), 171-216 and Dubowchik and Walker, Pharmacology & The Rapeutics 83 (1999), 67-123, the disclosures of which are incorporated herein by reference.

[0401] In some embodiments, the ligand is conjugated via the lysine ε-amino group. Most antibodies have multiple lysine ε-amino groups, which can be conjugated via amide, urea, thiourea, or carbamate linkages using techniques known in the art. However, it is difficult to control which ε-amino groups and how many ε-amino groups react, resulting in potential batch-to-batch variability in conjugate preparation. In addition, conjugation can lead to the neutralization of protonated ε-amino groups, which are important for maintaining the native conformation of the antibody, or conjugation can occur at lysines near or at the antigen-binding site, neither of which is an ideal situation.

[0402] In some embodiments, since many antibodies are glycosylated, the ligand can be conjugated via the carbohydrate side chain. The carbohydrate side chain can be oxidized with periodate to generate aldehyde groups, which can then react with amines to form imine groups, such as in semicarbazones, oximes, or hydrazones. If desired, the imine group can be converted to a more stable amine group by reduction with sodium cyanoborohydride. For additional disclosure regarding conjugation via carbohydrate side chains, see, e.g., Rodwell et al., Proc. Nat'l Acad. Sci. USA 83, 2632-2636 (1986); the disclosure of which is incorporated herein by reference. As with the lysine ε-amino group, there are concerns regarding the reproducibility of the conjugation site location and stoichiometry.

[0403] In some embodiments, the ligand can be conjugated via the carboxylic acid group. In some cases, the terminal carboxylic acid group is functionalized to generate a carbohydrazide, which then reacts with an aldehyde-containing conjugation moiety. See Fisch et al., Bioconjugate Chemistry 1992, 3, 147-153.

[0404] In some embodiments, antibodies can be conjugated by bridging a cysteine residue on the antibody with sulfur on the conjugate or another moiety of the compound via a disulfide bond. Some antibodies lack free thiol (mercapto) groups but have disulfide bonds, such as in the hinge region. In such cases, free thiol groups can be generated by reducing the native disulfide bonds. The thiol groups so generated can then be used for conjugation. See, for example, Packard et al., Biochemistry 1986, 25, 3548-3552; King et al., Cancer Res. 54, 6176-6185 (1994); and Doronina et al., Nature Biotechnol. 21(7), 778-784 (2003); the disclosures of which are incorporated herein by reference. There are a variety of known methods for introducing free thiol groups into antibodies without disrupting native disulfide bonds, and these methods can be practiced with the ligands of the present invention. Depending on the method employed, it may be possible to introduce a predictable number of free thiol groups at a predetermined position. In one method, mutant antibodies are prepared in which cysteine is replaced with another amino acid. See, for example, Eigenbrot et al., U.S. Patent No. 7,521,541 B2 (2009); Chilkoti et al., Bioconjugate Chem. 1994, 5, 504-507; Urnovitz et al., U.S. Patent No. 4,698,420 (1987); Stimmel et al., J. Biol. Chem., 275(39), 30445-30450 (2000); Bam et al., U.S. Patent No. 7,311,902 B2 (2007); Kuan et al., J. Biol. Chem., 269(10), 7610-7618 (1994); Poon et al., J. Biol. Chem., 270(15), 8571-8577 (1995). In another method, an additional cysteine is added to the C-terminus. See, for example, Cumber et al., J. Immunol., 149, 120-126 (1992); King et al., Cancer Res., 54, 6176-6185 (1994); Li et al., Bioconjugate Chem., 13, 985-995 (2002); Yang et al., Protein Engineering, 16, 761-770 (2003); and Olafson et al., Protein Engineering Design & Selection, 17, 21-27 (2004). A preferred method for introducing free cysteine is proposed by Liu et al. in WO2009 / 026274 A1, in which an amino acid sequence bearing cysteine is added to the C-terminus of the antibody heavy chain.This method introduces a known number of cysteine residues (one per heavy chain) at a known position remote from the antigen-binding site. The disclosures of the documents cited in this paragraph are hereby incorporated by reference in their entirety.

[0405] In some embodiments, the lysine ε-amino group can be modified with a reagent such as 2-iminothiolane or N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP) to convert the ε-amino group to a thiol or disulfide group, generating a cysteine surrogate, so to speak.

[0406] Linker

[0407] The compounds and salts of formula (I), formula (I)*, formula (I-A), formula (I-B), formula (II), formula (II)*, formula (III), formula (III)*, formula (IV)* or formula (IV-A)* can contain a linker (e.g., L). The linker can be as described elsewhere herein. In some cases, L is a peptide linker. In some embodiments, the linker also binds to a ligand (e.g., an antibody) and is referred to as an antibody-drug conjugate or conjugate. The linker of the conjugates described herein can not affect the binding of the active portion of the conjugate (e.g., antigen-binding domain, Fc domain, target-binding domain, antibody, agonist, etc.) to a target (which can be a cognate binding partner such as an antigen). The conjugate can contain multiple linkers, each linker having one or more attached compounds. These linkers can be the same linker or different linkers.

[0408] In some embodiments, the linker can be short, flexible, rigid, cleavable, non-cleavable, hydrophilic or hydrophobic. The linker can contain segments with different properties, such as flexible segments or rigid segments. The linker can be chemically stable in the extracellular environment, e.g., chemically stable in the bloodstream, or can include labile or selectively stable linkages. The linker can include linkages designed to be cleaved and / or sacrificed or otherwise degraded specifically or non-specifically intracellularly. Cleavable linkers can be sensitive to enzymes. Cleavable linkers can be cleaved by enzymes (such as proteases). Cleavable linkers can contain a valine-citrulline linker or a valine-alanine peptide. Linkers containing valine-citrulline or valine-alanine can contain maleimide or succinimide groups.

[0409] In some embodiments, the non-cleavable linker can be protease-insensitive. The non-cleavable linker can be a maleimidocaproyl linker. The maleimidocaproyl linker can comprise N-maleimidomethylcyclohexane-1-carboxylate. The maleimidocaproyl linker can contain a succinimide group. The maleimidocaproyl linker can contain a pentafluorophenyl group. The linker can be a combination of a maleimidocaproyl group and one or more polyethylene glycol molecules. The linker can be a maleimide-PEG4 linker. The linker can be a combination of a maleimidocaproyl linker containing a succinimide group and one or more polyethylene glycol molecules. The linker can be a combination of a maleimidocaproyl linker containing a pentafluorophenyl and one or more polyethylene glycol molecules. The linker can contain a maleimide attached to a polyethylene glycol molecule, where the polyethylene glycol can allow for greater linker flexibility or can be used to extend the linker. The linker can be a (maleimidocaproy)-(valine-citrulline)-(p-aminobenzyloxycarbonyl) linker. The linker can be a linker suitable for attachment to engineered cysteine (THIOMAB). The THIOMAB linker can be a (maleimidocaproy)-(valine-citrulline)-(p-aminobenzyloxycarbonyl) linker.

[0410] In some embodiments, the linker can further comprise alkylene, alkenylene, alkynylene, polyether, polyester, polyamide groups, and further comprise polyamino acids, polypeptides, cleavable peptides, or aminobenzyl carbamate. The linker can contain a maleimide at one end and an N-hydroxysuccinimide ester at the other end. The linker can contain N-terminal amine-acetylated lysine and a valine-citrulline cleavage site. The linker can be a linkage generated by microbial transglutaminase, where the linkage can be established between an amine-containing moiety and a moiety engineered to contain glutamine due to the enzyme-catalyzed formation of a bond between the acyl group of the glutamine side chain and the primary amine of a lysine chain. The linker can contain a reactive primary amine. The linker can be a sortase A linker. The sortase A linker can be created by a sortase A enzyme that fuses an LXPTG recognition motif with an N-terminal GGG motif, thereby regenerating a native amide bond. Thus, the created linker can connect the portion attached to the LXPTG recognition motif with the portion attached to the N-terminal GGG motif.

[0411] In some embodiments, any compound or salt described herein is linked to an antibody construct via a linker (also referred to herein as L or linker). As used herein, L can be selected from any of the linker moieties discussed herein. The linker that connects the compound or salt to the conjugate antibody construct can be short, long, hydrophobic, hydrophilic, flexible, or rigid, or can consist of segments that each independently have one or more of the above properties, such that the linker can include segments with different properties. The linker can be multivalent such that they covalently link more than one compound or salt to a single site on the antibody construct, or can be monovalent such that they covalently link a single compound or salt to a single site on the antibody construct.

[0412] In some embodiments, the linker can have from about 10 to about 500 atoms in the linker, such as from about 10 to about 400 atoms, such as from about 10 to about 300 atoms in the linker. In some embodiments, the linker can have from about 30 to about 400 atoms, such as from about 30 to about 300 atoms in the linker.

[0413] In some embodiments, the linker described herein can link any one of the compounds or salts of the formulas described herein to a ligand (e.g., an antibody) via a covalent linkage between the linker, the antibody construct, and the compound. The linker can include functional groups capable of covalently linking to a ligand (e.g., an antibody).

[0414] In some embodiments, by way of example and not limitation, some cleavable and non-cleavable linkers that can be included in the conjugates described herein are described below.

[0415] In some embodiments, the cleavable linker can be cleaved in vitro and in vivo. The cleavable linker can include chemically or enzymatically labile or degradable linkages. The cleavable linker can rely on intracellular processes to release the benzazepine compound, such as being reduced in the cytoplasm, exposed to acidic conditions in lysosomes, or cleaved by specific proteases or other enzymes within the cell. The cleavable linker can contain one or more chemically or enzymatically cleavable chemical bonds, while the remainder of the linker can be non-cleavable.

[0416] In some embodiments, the linker can contain chemically labile groups, such as hydrazones and / or disulfides. Linkers containing chemically labile groups can take advantage of the differential properties between plasma and some cytoplasmic compartments. Cleavable linkers can also include disulfides.

[0417] In some embodiments, acid-labile groups (such as hydrazones) can remain intact in the systemic circulation at the neutral pH of blood (pH 7.3 - 7.5), and once the antibody construct benzazepine Compound conjugates are internalized into the weakly acidic endosome (pH 5.0 - 6.5) and lysosome (pH 4.5 - 5.0) compartments of cells and can undergo hydrolysis and release benzazepines compounds. This pH-dependent release mechanism can be associated with non-specific release of the drug. To improve the stability of the linker hydrazone group, the linker can be modified chemically (e.g., substituted) to allow tuning for more efficient release in lysosomes while minimizing losses in circulation. Hydrazone-containing linkers can contain additional cleavage sites, such as additional acid-labile cleavage sites and / or enzymatically labile cleavage sites. Other acid-labile groups that can be included in the linker include cis-aconityl-containing linkers. Cis-aconityl chemistry can use a carboxylic acid juxtaposed to an amide bond to accelerate hydrolysis of the amide under acidic conditions.

[0418] In some embodiments, the linker can be specifically cleaved by an enzyme. For example, the linker can be cleaved by lysosomal enzymes. Such linkers can be peptide-based or can include peptide regions that can serve as substrates for enzymes. Peptide-based linkers can be more stable in the plasma and extracellular environment compared to chemically labile linkers. Peptide bonds can have good serum stability because lysosomal proteolytic enzymes can have very low activity in blood due to the presence of endogenous inhibitors and the inappropriately high pH of blood compared to lysosomes. Release of the compounds described herein from antibody-drug conjugates can occur due to the action of lysosomal proteases (e.g., cathepsins and plasmin). These proteases can be present at elevated levels in certain tumor tissues. The linker can be cleaved by lysosomal enzymes. Lysosomal enzymes can be, for example, cathepsin B, cathepsin S, β-glucuronidase, or β-galactosidase. Cleavable peptides can be selected from tetrapeptides, such as Gly-Phe-Leu-Gly, Ala-Leu-Ala-Leu, or dipeptides, such as Val-Cit, Val-Ala, and Phe-Lys. Dipeptides can have lower hydrophobicity compared to long peptides. A variety of dipeptide-based cleavable linkers can be used in the antibody-drug conjugates described herein. Enzymatically cleavable linkers can be β-glucuronide-based linkers.

[0419] In some embodiments, the cleavable linker can include non-cleavable moieties or segments, and / or cleavable segments or moieties can be included in an otherwise non-cleavable linker to make it cleavable.

[0420] In some embodiments, the linker may contain an enzymatically cleavable peptide moiety. The peptide may be selected from natural amino acids, unnatural amino acids, or combinations thereof. In certain embodiments, the peptide may be selected from tripeptides or dipeptides. In a particular embodiment, the dipeptide may comprise L-amino acids and is selected from: Val-Cit; Cit-Val; Ala-Ala; Ala-Cit; Cit-Ala; Asn-Cit; Cit-Asn; Cit-Cit; Val-Glu; Glu-Val; Ser-Cit; Cit-Ser; Lys-Cit; Cit-Lys; Asp-Cit; Cit-Asp; Ala-Val; Val-Ala; Phe-Lys; Lys-Phe; Val-Lys; Lys-Val; Ala-Lys; Lys-Ala; Phe-Cit; Cit-Phe; Leu-Cit; Cit-Leu; Ile-Cit; Cit-Ile; Phe-Arg; Arg-Phe; Cit-Trp; and Trp-Cit or salts thereof.

[0421] Pharmaceutical preparation

[0422] In certain embodiments, provided herein are compositions comprising a therapeutically effective amount of any compound or salt of any one of formula (I), formula (I)*, formula (I-A), formula (I-B), formula (II), formula (II)*, formula (III), formula (III)*, formula (IV), formula (IV)*, formula (IV-A)*, formula (V-A), formula (V-B), formula (V-C), or formula (V-D) (also referred to herein as "agent").

[0423] The pharmaceutical compositions can be formulated using one or more physiologically acceptable carriers (including excipients and auxiliaries), which assist in processing the medicaments into pharmaceutical formulations. The appropriate formulation depends on the chosen route of administration. An overview of pharmaceutical compositions is found, for example, in Remington: The Science and Practice of Pharmacy, 19th Edition (Easton, Pa., Mack Publishing Company, 1995); Hoover, John E., Remington’s Pharmaceutical Sciences, Mack Publishing Co., Easton, Pennsylvania 1975; Liberman, H.A. and Lachman, L., eds., Pharmaceutical Dosage Forms, Marcel Decker, New York, N.Y., 1980; and Pharmaceutical Dosage Forms and Drug Delivery Systems, 7th Edition (Lippincott Williams & Wilkins, 1999).

[0424] The compositions and methods of the present disclosure can be used to treat an individual in need. In certain embodiments, the individual is a mammal such as a human or non-human mammal. When administered to an animal (such as a human), the composition or medicament is preferably administered in the form of a pharmaceutical composition, which comprises, for example, the medicament and a pharmaceutically acceptable carrier or excipient. Pharmaceutically acceptable carriers are well known in the art and include, for example, aqueous solutions (such as water or physiological buffer saline) or other solvents or vehicles (such as ethylene glycol, glycerol, oils (such as olive oil) or injectable organic esters). In a preferred embodiment, when such pharmaceutical compositions are used for human administration, particularly for invasive routes of administration (such as injection or implantation routes that circumvent transport or diffusion through an epithelial barrier), the aqueous solution is pyrogen-free or substantially pyrogen-free. For example, excipients can be selected to achieve delayed release of the agent or to selectively target one or more cells, tissues, or organs. The pharmaceutical compositions can be in dosage unit form, such as tablets, capsules, granules, reconstitutable lyophilized agents, powders, solutions, syrups, suppositories, injections, etc. The compositions can also be present in a transdermal administration system, such as a skin patch. The compositions can also be present in a solution suitable for topical administration, such as eye drops.

[0425] Pharmaceutically acceptable excipients may contain physiologically acceptable agents, such as to stabilize, increase solubility or increase absorption of a compound (such as a medicament). Such physiologically acceptable agents include, for example, carbohydrates (such as glucose, sucrose or dextran), antioxidants (such as ascorbic acid or glutathione), chelating agents, low molecular weight proteins or other stabilizers or excipients. The choice of pharmaceutically acceptable excipients (including physiologically acceptable agents) depends, for example, on the route of administration of the composition. The formulation or pharmaceutical composition may be a self-emulsifying drug delivery system or a self-microemulsifying drug delivery system. The pharmaceutical composition (formulation) may also be a liposome or other polymeric matrix, which may have incorporated therein, for example, a compound of the present invention. For example, liposomes containing phospholipids or other lipids are non-toxic, physiologically acceptable and metabolizable carriers, which are relatively simple to prepare and administer.

[0426] The pharmaceutical composition (formulation) may be administered to a subject by any of a variety of routes of administration, including, for example, oral, such as drenches in the form of: aqueous or non-aqueous solutions or suspensions, tablets, capsules (including sprinkle capsules and gelatin capsules), boluses, powders, granules, pastes for application to the tongue; absorption through the oral mucosa, such as sublingual absorption; absorption through the anus, rectum or vagina, such as in the form of vaginal suppositories, creams or foams; parenteral administration, including intramuscular, intravenous, subcutaneous or intrathecal, such as in the form of a sterile solution or suspension; nasal administration; intraperitoneal administration; subcutaneous administration; transdermal administration, such as in the form of a patch applied to the skin; and topical administration, such as in the form of a cream, ointment or spray applied to the skin, or in the form of eye drops. The compound may also be formulated for inhalation. In certain embodiments, the compound may simply be dissolved or suspended in sterile water.

[0427] The pharmaceutical composition may be a sterile aqueous or non-aqueous solution, suspension or emulsion, such as a microemulsion. The excipients described herein are merely examples and do not constitute any limitation. An effective amount or a therapeutically effective amount refers to the amount of one or more medicaments administered to a subject in a single dose or as part of a series of doses, which amount is effective to produce the desired therapeutic effect.

[0428] Generally, assays and methods suitable for the condition being treated can be used to monitor the therapeutic effect of a subject, and these assays are familiar to those skilled in the art and are described herein. The pharmacokinetics of a medicament or one or more of its metabolites administered to a subject can be monitored by determining the level of the medicament or metabolite in a biological fluid from the subject (such as blood, blood fractions (such as serum) and / or urine, and / or other biological samples or biological tissues from the subject). Any method for detecting an agent practiced in the art and described herein can be used to measure the level of the medicament or metabolite during a course of treatment.

[0429] The dosage of the pharmaceutical agents described herein for treating a disease or disorder can depend on the condition of the subject, i.e., the stage of the disease, the severity of the symptoms caused by the disease, the overall health status, as well as age, sex, and weight, and other factors that will be apparent to those skilled in the medical arts. The pharmaceutical composition can be administered in a manner suitable for the disease to be treated as determined by those skilled in the medical arts. In addition to the factors related to the use of the pharmaceutical agents for treating a disease or disorder described herein and above, the appropriate duration and frequency of administration of the pharmaceutical agent can also be determined or adjusted based on factors such as the patient's condition, the type and severity of the patient's disease, the specific form of the active ingredient, and the method of administration. The optimal dosage of the agent can generally be determined using experimental models and / or clinical trials. The optimal dosage can depend on the body mass, weight, or blood volume of the subject. It is generally preferred to use the minimum dosage sufficient to provide effective treatment. The design and conduct of preclinical and clinical studies of the pharmaceutical agents described herein (including those administered for prophylactic benefits) are entirely within the skills of those skilled in the relevant art. When two or more pharmaceutical agents are administered to treat a disease or disorder, the optimal dosage of each agent can be different, such as lower than the dosage when either agent is used alone as a monotherapy. In certain specific embodiments, the combination of two agents can act synergistically or additively, and the dosage of either agent can be lower than the dosage when administered alone. The amount of the pharmaceutical agent that can be administered daily can be, for example, about 0.01 mg / kg to 100 mg / kg, such as about 0.1 to 1 mg / kg, about 1 to 10 mg / kg, about 10 - 50 mg / kg, about 50 - 100 mg / kg body weight. In other embodiments, the amount of the pharmaceutical agent that can be administered daily is about 0.01 mg / kg to 1000 mg / kg body weight, about 100 - 500 mg / kg body weight, or about 500 - 1000 mg / kg body weight. The optimal dosage per day or per course of treatment can vary depending on the disease or disorder to be treated and can also vary depending on the route of administration and the treatment regimen.

[0430] The pharmaceutical composition comprising the pharmaceutical agent can be formulated in a manner suitable for the delivery method using techniques conventional in the art. The composition can be in solid (e.g., tablets, capsules), semi-solid (e.g., gels), liquid, or gaseous (e.g., aerosols) form. In other embodiments, the pharmaceutical composition is administered by bolus infusion.

[0431] In the pharmaceutical field, pharmaceutically acceptable excipients are well-known and described, for example, in Rowe et al., Handbook of Pharmaceutical Excipients: A Comprehensive Guide to Uses, Properties, and Safety, 5th Edition, 2006 and Remington: The Science and Practice of Pharmacy (Gennaro, 21st Edition Mack Pub. Co., Easton, PA (2005)). Exemplary pharmaceutically acceptable excipients include sterile normal saline and phosphate buffered saline at physiological pH. Preservatives, stabilizers, dyes, buffers, etc. can be provided in the pharmaceutical composition. In addition, antioxidants and suspending agents can also be used. Generally, the choice of excipient type is based on the mode of administration and the chemical composition of the active ingredient. Alternatively, the compositions described herein can be formulated as lyophilizates. The compositions described herein can be lyophilized or otherwise formulated into a lyophilized product using one or more suitable excipient solutions for dissolving and / or diluting the pharmaceutical composition upon administration. In other embodiments, the pharmaceutical agent can be encapsulated in liposomes using techniques known and practiced in the art. In certain specific embodiments, the pharmaceutical agent is not formulated in liposomes for use in stents for treating highly (but not completely) occluded arteries. The pharmaceutical composition can be formulated for any suitable mode of administration described herein and in the art.

[0432] Pharmaceutical compositions, such as those for oral administration or injection, infusion, subcutaneous delivery, intramuscular delivery, intraperitoneal delivery, or other methods, can be in liquid form. Liquid pharmaceutical compositions can include, for example, one or more of the following: sterile diluents such as water, saline solutions (preferably normal saline), Ringer's solution, isotonic sodium chloride, fixed oils that can be used as solvents or suspending media, polyethylene glycol, glycerin, propylene glycol, or other solvents; antibacterial agents; antioxidants; chelating agents; buffers, and agents for adjusting tonicity such as sodium chloride or dextrose. Parenteral compositions can be enclosed in ampoules, disposable syringes, or multi-dose vials made of glass or plastic. Normal saline is preferably used, and injectable pharmaceutical compositions are preferably sterile. In another embodiment, for treating ophthalmic conditions or diseases, the liquid pharmaceutical composition can be administered to the eye in the form of eye drops. The liquid pharmaceutical composition can be delivered orally.

[0433] For oral formulations, at least one of the agents described herein can be used alone or in combination with suitable additives to prepare tablets, powders, granules or capsules, and used in combination with diluents, buffers, wetting agents, preservatives, coloring agents and flavoring agents, if desired. The agent can be formulated with a buffer to provide protection of the compound from the low pH of the gastric environment and / or an enteric coating. The agent included in the pharmaceutical composition can be formulated with a flavoring agent (e.g., in liquid, solid or semi-solid formulations) and / or with an enteric coating for oral administration.

[0434] A pharmaceutical composition comprising any one of the agents described herein can be formulated for sustained or slow release, also known as timed release or controlled release. Such compositions can generally be prepared using well-known techniques and administered, for example, orally, rectally, intradermally or subcutaneously by implantation, or implanted at the desired target site. Sustained release formulations can contain a compound dispersed in a carrier matrix and / or a compound contained in a reservoir surrounded by a rate-controlling membrane. The excipients used in such formulations are biocompatible and can also be biodegradable; preferably the formulation provides a relatively constant level of release of the active ingredient. The amount of the agent contained in the sustained release formulation depends on the implantation site, the release rate and the expected duration, as well as the nature of the condition, disease or disorder to be treated or prevented.

[0435] In certain embodiments, a pharmaceutical composition comprising an agent is formulated for transdermal, intradermal or topical administration. The composition can be administered in the form of a powder / talc or other solid, liquid, spray, aerosol, ointment, foam, cream, gel, paste using a syringe, bandage, transdermal patch, insert or syringe-like applicator. This is preferably in the form of a controlled release formulation or a sustained release formulation, which is administered, for example, intradermally or subcutaneously topically or directly injected into the skin adjacent to or within the area to be treated. The active composition can also be delivered by iontophoresis. Preservatives can be used to prevent the growth of fungi and other microorganisms. Suitable preservatives include, but are not limited to, benzoic acid, butylparaben, ethylparaben, methylparaben, propylparaben, sodium benzoate, sodium propionate, benzalkonium chloride, benzethonium chloride, benzyl alcohol, cetylpyridinium chloride, chlorobutanol, phenol, phenethyl alcohol, thimerosal and combinations thereof.

[0436] A pharmaceutical composition containing a medicament can be formulated as an emulsion for topical application. The emulsion contains a liquid distributed in a second liquid. The emulsion can be an oil-in-water emulsion or a water-in-oil emulsion. Either or both of the oil phase and the water phase can contain one or more surfactants, emulsifiers, emulsion stabilizers, buffers, and other excipients. The oil phase can contain other oily pharmaceutically approved excipients. Suitable surfactants include, but are not limited to, anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. The composition for topical application can also include at least one suitable suspending agent, antioxidant, chelating agent, emollient, or humectant.

[0437] Ointments and creams can be formulated, for example, with an aqueous or oily base, to which suitable thickeners and / or gelling agents are added. Lotions can be formulated with an aqueous or oily base and generally also contain one or more emulsifiers, stabilizers, dispersants, suspending agents, thickeners, or colorants. Liquid sprays can be delivered by a pressurized package, for example, through a specially shaped cap. Oil-in-water emulsions can also be used in compositions, patches, bandages, and articles. These systems are semi-solid emulsion, microemulsion, or foam emulsion systems.

[0438] In some embodiments, the medicaments described herein can be formulated as inhalants. The inhalation method can deliver the drug directly to the airways. The medicaments can be formulated as aerosols, microspheres, liposomes, or nanoparticles. The medicaments can be formulated with solvents, gases, nitrates, or any combination thereof. The compositions described herein are optionally formulated as liquid aerosols or inhalable dry powders for delivery. Liquid aerosol formulations are optionally atomized primarily into particle sizes that can be delivered to the terminal bronchioles and respiratory bronchioles. Liquid aerosol and inhalable dry powder formulations are preferably delivered through the entire intratracheal tree to the terminal bronchioles and ultimately to the parenchymal tissue.

[0439] The aerosolized formulations described herein are optionally delivered using an aerosol-forming device (such as a nebulizer, vibrating perforated plate, or ultrasonic nebulizer), preferably selected to allow the formation of aerosol particles with a mass median average diameter mainly between 1 and 5 μm. In addition, the formulations preferably have a balanced osmotic pressure, ionic strength, and chloride concentration, and a minimum aerosolizable volume capable of delivering an effective dose of the medicament. In addition, the aerosolized formulations preferably have no negative impact on airway function and do not cause undesirable side effects.

[0440] A nebulizing device suitable for administering the aerosol formulations described herein includes, for example, jet, vibrating porous plate, ultrasonic nebulizers, and electrically powered dry powder inhalers, which are capable of nebulizing the formulation into aerosol particle sizes mainly in the range of 1-5 μm. By "main" in this application is meant that at least 70% but preferably more than 90% of all the aerosol particles produced are in the range of 1-5 μm. The working principle of a jet nebulizer is to break a liquid solution into aerosol droplets by air pressure. The working principle of a vibrating porous plate nebulizer is to extrude solvent droplets through a porous plate by acoustic vacuum generated by using a rapidly vibrating porous plate. The working principle of an ultrasonic nebulizer is to shear a liquid into small aerosol droplets by a piezoelectric crystal. A variety of suitable devices are available, including, for example, the AeroNeb™ and AeroDose™ vibrating porous plate nebulizers (AeroGen, Inc., Sunnyvale, California), nebulizer (Medic-Aid Ltd., West Sussex, England), Pari Pari LC jet nebulizer (Pari Respiratory Equipment, Inc., Richmond, Virginia) and Aerosonic™ (DeVilbiss Medizinische Produkte (Deutschland) GmbH, Heiden, Germany) and (Omron Healthcare, Inc., Vernon Hills, Illinois) ultrasonic nebulizers.

[0441] In some embodiments, the medicament can be formulated with an oily matrix or ointment to form a semi-solid composition having a desired shape. In addition to the medicament, these semi-solid compositions can contain dissolved and / or suspended bactericides, preservatives, and / or buffer systems. The petrolatum component that can be included can be any petrolatum with a viscosity range from mineral oil admixed with isobutene, colloidal silica, or stearate to paraffin wax. Absorbent matrices can be used with the oily systems. Additives can include cholesterol, lanolin (lanolin derivatives, beeswax, fatty alcohols, lanolin alcohols, low HLB (hydrophilic-lipophilic balance) emulsifiers, and various ionic and non-ionic surfactants, alone or in combination.

[0442] Controlled release or sustained release transdermal or topical formulations can be achieved by adding sustained release additives available in the art, such as polymeric structures, matrices. For example, the composition can be administered by using a hot melt extrusion product, such as a bioadhesive hot melt extrusion film. The formulation can comprise a cross-linked polycarboxylic acid polymer formulation. The cross-linking agent can be present in an amount sufficient to provide sufficient adhesion to allow the system to remain attached to the target epithelial or endothelial cell surface for a sufficient time to allow the desired release of the compound.

[0443] Inserts, transdermal patches, bandages or articles can comprise a polymer blend or coating that provides a constant rate of release of the medicament over a longer period of time. In some embodiments, the article, transdermal patch or insert comprises a water-soluble pore former, such as polyethylene glycol (PEG), which can be mixed with a water-insoluble polymer to increase the durability of the insert and extend the release of the active ingredient.

[0444] Transdermal devices (inserts, patches, bandages) can also comprise water-insoluble polymers. Rate controlling polymers can be useful for administration to sites where pH changes can be used to affect release. These rate controlling polymers can be applied during the spray and drying process with the active compound using a continuous coating film. In one embodiment, a coating formulation is used to coat pellets comprising the active ingredient, and these pellets are compressed to form solid, biodegradable inserts.

[0445] Polymeric formulations can also be used to provide controlled release or sustained release. Bioadhesive polymers described in the art can be used. By way of example, sustained release gels and compounds can be incorporated into a polymer matrix, such as a hydrophobic polymer matrix. Examples of polymer matrices include microparticles. The microparticles can be microspheres, and the core can be of a different material than the polymer shell. Alternatively, the polymer can be cast into slabs or films, powders or gels (such as hydrogels) produced by milling or other standard techniques. The polymer can also be in the form of a coating or part of a bandage, stent, catheter, vascular graft or other device to facilitate the delivery of the medicament. The matrix can be formed by solvent evaporation, spray drying, solvent extraction and other methods known to those skilled in the art.

[0446] Kits having unit doses of one or more of the medicaments described herein are generally provided in oral or injectable doses. Such kits can include a container containing the unit dose, an informational package insert describing the use of the drug in treating the disease and the attendant benefits, and optionally an appliance or device for delivering the composition.

[0447] Methods of treatment

[0448] In one aspect, the present disclosure provides a method of treating a subject having a tumor. In some cases, treating a subject having a tumor includes administering to a subject in need thereof a compound or salt of any one of Formula (I), Formula (I)*, Formula (I-A), Formula (I-B), Formula (II), Formula (II)*, Formula (III), Formula (III)*, Formula (IV), Formula (IV)*, Formula (IV-A)*, Formula (V-A), Formula (V-B), Formula (V-C), Formula (V-D), or a pharmaceutical composition thereof. In some cases, the tumor is associated with cancer. In some cases, the cancer is selected from lung cancer, kidney cancer, urethral cancer, colorectal cancer, prostate cancer, glioblastoma multiforme, ovarian cancer, pancreatic cancer, breast cancer, melanoma, liver cancer, bladder cancer, gastric cancer, and esophageal cancer.

[0449] In some embodiments, the compounds described herein can be used to treat diseases or disorders such as, but not limited to, hyperproliferative diseases, including: cancers of the head and neck, which include tumors of the head, neck, nasal cavity, paranasal sinuses, nasopharynx, oral cavity, oropharynx, larynx, hypopharynx, salivary glands, and paraganglioma; cancers of the liver and biliary system, particularly hepatocellular carcinomas; bowel cancers, particularly colorectal cancers; ovarian cancers; small cell and non-small cell lung cancers (SCLC and NSCLC); breast sarcomas, such as fibrosarcoma, malignant fibrous histiocytoma, embryonal rhabdomyosarcoma, leiomyosarcoma, neurofibrosarcoma, osteosarcoma, synovial sarcoma, liposarcoma, and alveolar soft part sarcoma; leukemias, such as acute promyelocytic leukemia (APL), acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), and chronic myeloid leukemia (CML); neoplasms of the central nervous system, particularly brain cancers; multiple myeloma (MM); lymphomas, such as Hodgkin lymphoma, lymphoplasmacytic lymphoma, follicular lymphoma, mucosa-associated lymphoid tissue lymphoma, mantle cell lymphoma, B-cell large cell lymphoma, Burkitt lymphoma, and T-cell anaplastic large cell lymphoma. Clinically, practicing the methods described herein and using the compositions described herein will result in a decrease in the size or number of cancerous growths and / or alleviation of associated symptoms (where applicable). Pathologically, practicing the methods described herein and using the compositions described herein will produce a pathologically relevant response, such as: inhibition of cancer cell proliferation, reduction in the size of the cancer or tumor, prevention of further metastasis, and inhibition of tumor angiogenesis. Methods of treating such diseases include administering to a subject a therapeutically effective amount of the combination of the present invention. The method can be repeated as needed. The cancer can be kidney cancer, lung cancer, gastric cancer, or ovarian cancer. In some cases, the cancer includes malignancies of various organ systems, such as malignancies affecting the skin, lung, breast, thyroid, lymph, gastrointestinal, and urogenital tracts, and adenocarcinomas, which include malignancies such as most colon cancers, renal cell carcinomas, prostate cancers, and / or testicular tumors, non-small cell carcinomas of the lung, small intestine cancers, and esophageal cancers.

[0450] In some embodiments, treatment of a tumor-bearing subject inhibits tumor growth by at least about 20%, more preferably at least about 40%, even more preferably at least about 60%, and still even more preferably at least about 80% relative to an untreated subject. A therapeutically effective amount of a therapeutic compound can reduce tumor size or otherwise improve the symptoms of the subject, which is typically a human but can be another mammal.

[0451] In some embodiments, the compounds described herein can be administered in combination with other therapeutic agents, including antibodies, alkylating agents, angiogenesis inhibitors, antimetabolites, DNA cleaving agents, DNA cross-linking agents, DNA intercalating agents, DNA minor groove binders, enediynes, heat shock protein 90 inhibitors, histone deacetylase inhibitors, immunomodulators, microtubule stabilizers, nucleoside (purine or pyrimidine) analogs, nuclear export inhibitors, proteasome inhibitors, topoisomerase (I or II) inhibitors, tyrosine kinase inhibitors, and serine / threonine kinase inhibitors. Specific therapeutic agents include adalimumab, ansamitocin P3, auristatins, bendamustine, bevacizumab, bicalutamide, bleomycin, bortezomib, busulfan, callistatin A, camptothecin, capecitabine, carboplatin, carmustine, cetuximab, cisplatin, cladribine, cytarabine, cryptophycins, dacarbazine, dasatinib, daunorubicin, docetaxel, doxorubicin, duocarmycin, dynemycin A, epothilones, etoposide, floxuridine, fludarabine, 5-fluorouracil, gefitinib, gemcitabine, ipilimumab, hydroxyurea, imatinib, infliximab, interferons, interleukins, β-lapachone, lenalidomide, irinotecan, maytansine, mechlorethamine, melphalan, 6-mercaptopurine, methotrexate, mitomycin C, nilotinib, oxaliplatin, paclitaxel, procarbazine, suberoylanilide hydroxamic acid (SAHA), 6-thioguanine, thiotepa, teniposide, topotecan, trastuzumab, trichostatin A, vinblastine, vincristine, and vindesine.

[0452] The compounds described herein can be used to prepare a medicament for preventing or treating a disease or condition. In addition, a method for treating any disease or condition described herein in a subject in need of such treatment involves administering to the subject a therapeutically effective amount of a pharmaceutical composition comprising at least one compound described herein or a pharmaceutically acceptable salt, pharmaceutically acceptable prodrug, or pharmaceutically acceptable solvate thereof.

[0453] Compositions containing the compounds described herein can be administered for prophylactic and / or therapeutic treatment. In therapeutic applications, the compositions are administered to a patient who has a disease or condition in an amount sufficient to cure or at least partially alleviate the symptoms of the disease or condition. The amount effective for this use will depend on the severity and course of the disease or condition, previous treatment, the health status, weight, response to the drug, and the judgment of the attending physician of the patient.

[0454] In prophylactic applications, the compositions containing the compounds described herein are administered to a patient who is predisposed to or at risk of developing a particular disease, disorder, or condition. Such an amount is defined as a "prophylactically effective amount or dose". In this use, the exact amount also depends on the health status, weight, etc. of the patient. When used in a patient, the amount effective for this use will depend on the severity and course of the disease, disorder, or condition, previous treatment, the health status and response to the drug of the patient, and the judgment of the attending physician.

[0455] In cases where the condition of the patient does not improve, long-term administration can be carried out according to the judgment of the physician administering the compound, i.e., over a relatively long period of time, including throughout the duration of the patient's life, in order to improve or otherwise control or limit the symptoms of the patient's disease or condition.

[0456] Once improvement in the patient's condition has occurred, a maintenance dose is administered if necessary. Subsequently, the dose or the frequency of administration, or both, can be reduced according to the symptoms until the disease, disorder, or condition is improved and maintained at a certain level. However, the patient may need intermittent treatment on a long-term basis whenever any symptoms recur.

[0457] The amount of a given pharmaceutical agent corresponding to this amount will vary depending on a variety of factors, such as the specific compound, the disease or condition and its severity, the identity of the subject or host to be treated (e.g., weight), but can still be determined in a manner recognized in the art according to the specific circumstances surrounding the case, including, for example, the specific pharmaceutical agent administered, the route of administration, the condition being treated, and the subject or host being treated. However, generally speaking, the dose for adult treatment is usually in the range of about 0.02 to about 5000 mg per day, and in some embodiments, about 1 to about 1500 mg per day. The desired dose can be conveniently administered as a single dose or divided doses simultaneously (or over a short period of time) or at appropriate intervals, such as in two, three, four, or more divided doses per day.

[0458] The pharmaceutical compositions described herein may be in unit dosage forms suitable for single, precise dosage administration. In a unit dosage form, the formulation is divided into unit doses containing a suitable amount of one or more compounds. The unit doses may be in a package containing a discrete amount of the formulation. Non-limiting examples are packaged tablets or capsules, and powders in vials or ampoules. An aqueous suspension composition may be packaged in a single-dose non-refillable container. Alternatively, a multi-dose refillable container may be used, in which case a preservative is typically included in the composition. By way of example only, a formulation for parenteral injection may be presented in unit dosage form, including but not limited to in an ampoule or in a multi-dose container, where a preservative is added.

[0459] The toxicity and therapeutic efficacy of such treatment regimens can be determined by standard pharmacological procedures in cell cultures or experimental animals, including but not limited to determining the LD 50 (the dose that is lethal to 50% of the population) and the ED 50 (the dose that is therapeutically effective in 50% of the population). The dose ratio between the toxic and therapeutic effects is the therapeutic index, and it can be expressed as the ratio of LD 50 to ED 50 . Compounds with a high therapeutic index are preferably exhibited. Data obtained from cell culture assays and animal studies can be used to formulate a dosage range for human use. The dosage of such compounds is preferably within a circulating concentration range that includes the ED 50 and is the least toxic. The dosage may vary within this range depending on the dosage form employed and the route of administration utilized.

[0460] In certain embodiments, the present invention provides a method of treating or preventing a disease, condition, or disorder in a patient in need thereof, comprising administering to the patient an effective amount of a compound or a pharmaceutically acceptable salt thereof of any embodiment of the present invention. The disease, condition, or disorder may be selected from the groups described elsewhere herein.

[0461] Preparation of Compounds

[0462] The compounds of the present disclosure can generally be prepared by a variety of methods well known to those skilled in the art of organic synthesis. By way of example, the compounds of the present disclosure can be synthesized using the methods described herein as well as synthetic methods known in the art of synthetic organic chemistry or variants thereof as understood by those skilled in the art. The compounds of the present disclosure can be prepared according to the schemes and examples described elsewhere herein.

[0463] The following examples further illustrate the invention, but should of course not be construed as limiting its scope in any way.

[0464] Examples

[0465] The following synthetic schemes are provided for illustrative purposes and not for limitation. The following examples illustrate various methods for preparing the compounds described herein. It should be understood that those skilled in the art can prepare these compounds by similar methods or by combining other methods known to those skilled in the art. It should also be understood that those skilled in the art will be able to prepare them in a manner similar to that described below by using appropriate starting materials and modifying the synthetic routes as needed. Generally, the starting materials and reagents can be obtained from commercial suppliers or synthesized from sources known to those skilled in the art or prepared as described herein. The following abbreviations, as used below and throughout the specification of the present invention, should be understood to have the following meanings unless otherwise indicated:

[0466]

[0467]

[0468]

[0469] Preparation of Drug Linker

[0470] Example 1: Synthesis of Compound 11

[0471]

[0472] Compound 3: To a solution of SN-38 (Compound 1, 1.57 g, 4 mmol) in DMF (20 mL) was added Compound 2 (1.4 g, 8 mmol) and DBU (0.6 g, 4 mmol). The reaction mixture was stirred at 50 °C for 2 h and then directly purified by RP-HPLC to give Compound 3 (0.42 g) as a yellow solid after lyophilization.

[0473] Compound 4: Compound 3 (0.4 g) was suspended in DCM (6 mL) and TFA (4 mL) was added. The mixture was stirred at room temperature for 2 h. Then the reaction was concentrated to dryness under reduced pressure. The residue was purified by RP-HPLC to give Compound 4 (238 mg) as a yellow solid after lyophilization.

[0474] Compound 6: To a solution of Compound 4 (204 mg, 0.47 mmol) in a mixture of DCM (4 mL) and TFA (1 mL) was added Compound 5 (860 mg, 2.34 mmol). The mixture was stirred at room temperature for 1 h. Then the solvent was removed under vacuum and the mixture was purified by RP-HPLC. The fractions were lyophilized to give Compound 6 (271 mg) as a pale yellow solid.

[0475] Compound 7: Piperidine (0.2 mL) was added to a solution of Compound 6 (271 mg, 0.36 mmol) in DMF (2 mL). The mixture was stirred at room temperature for 10 min and then purified by RP-HPLC. The fractions were lyophilized to give Compound 7 (191 mg) as a pale yellow solid.

[0476] Compound 9: Compound 8 (92 mg, 0.18 mmol), DIEA (128 μL, 0.74 mmol), and PyAOP (96 mg, 0.18 mmol) were added to a solution of Compound 7 (TFA salt, 114 mg, 0.18 mmol) in DMF (2 mL). The mixture was stirred at room temperature for 10 min and then piperidine (0.2 mL) was added. Stirring was continued for an additional 10 min and then the mixture was purified by RP-HPLC. The fractions were lyophilized to give Compound 9 (84 mg) as a pale yellow solid.

[0477] Compound 11: HATU (6.4 mg, 16.7 μmol) and DIEA (8.6 μL, 50 μmol) were added to a solution of Compound 10 (4.1 mg, 16.7 μmol) in DMF (1 mL). The mixture was stirred at room temperature for 1 min and then Compound 9 (TFA salt, 15 mg, 16.7 μmol) was added. Stirring was continued for an additional 10 min and then the mixture was purified by RP-HPLC. The fractions were lyophilized to give Compound 11 (12 mg) as a pale yellow solid. MS: 1011.8 [M+H] + 。

[0478] Example 2: Synthesis of Compound 13

[0479]

[0480] HATU (6.4 mg, 16.7 μmol) and DIEA (8.6 μL, 50 μmol) were added to a solution of Compound 12 (4.1 mg, 16.7 μmol) in DMF (1 mL). The mixture was stirred at room temperature for 1 min and then Compound 9 (TFA salt, 15 mg, 16.7 μmol) was added. Stirring was continued for an additional 10 min and then the mixture was purified by RP-HPLC. The fractions were lyophilized to give Compound 13 (12 mg) as a pale yellow solid. MS: 1011.4 [M+H] + 。

[0481] Example 3: Synthesis of Compound 15

[0482]

[0483] To a solution of Compound 9 (TFA salt, 15 mg, 16.7 μmol) in DMF (1 mL) was added Compound 14 (6.3 mg, 16.7 μmol) and DIEA (8.6 μL, 50 μmol). The mixture was stirred at room temperature for 10 min, and then the mixture was purified by RP-HPLC. The fractions were lyophilized to give Compound 15 (13 mg) as a pale yellow solid. MS: 977.4 [M+H] + 。

[0484] Example 4: Synthesis of Compound 18

[0485]

[0486] Compound 17: To a solution of Compound 16 (10.3 mg, 21.2 μmol) in DMF (1 mL) was added HATU (8.1 mg, 21.2 μmol) and DIEA (15 μL, 86 μmol). The mixture was stirred at room temperature for 1 min, and then Compound 9 (TFA salt, 19 mg, 21.2 μmol) was added. The mixture was stirred at room temperature for 10 min, and then piperidine (0.2 mL) was added. Stirring was continued for an additional 10 min, and then the mixture was purified by RP-HPLC. The fractions were lyophilized to give Compound 17 (21 mg) as a pale yellow solid.

[0487] Compound 18: To a solution of Compound 10 (4.1 mg, 16.7 μmol) in DMF (1 mL) was added HATU (6.4 mg, 16.7 μmol) and DIEA (8.6 μL, 50 μmol). The mixture was stirred at room temperature for 1 min, and then Compound 17 (TFA salt, 19.1 mg, 16.7 μmol) was added. Stirring was continued for an additional 10 min, and then the mixture was purified by RP-HPLC. The fractions were lyophilized to give Compound 18 (13 mg) as a pale yellow solid. MS: 1258.6 [M+H] + 。

[0488] Example 5: Synthesis of Compound 6

[0489]

[0490] Compound 3:

[0491] A mixture of Compound 1 (TFA salt, 150 mg, 0.38 mmol), p-toluenesulfonic acid (36 mg, 0.21 mmol) and Compound 2 (100 mg, 0.38 mmol) in 20 mL of toluene was refluxed for 24 h. The solvent was removed in vacuo, and the remaining residue was purified by RP-HPLC to give Compound 3 (16 mg) as a brown solid.

[0492] Compound 5:

[0493] To a solution of Compound 3 (TFA salt, 7 mg, 13.9 μmol) in anhydrous DMF (2 mL) was added Acid 4 (2.3 mg, 13.9 μmol), PyAOP (7.2 mg, 13.9 μmol) and DIEA (10 μL, 55.4 μmol). The mixture was stirred at room temperature for 1 h. The mixture was then purified directly by RP-HPLC to give Compound 5 (4 mg) as a tan solid.

[0494] Compound 6:

[0495] Compound 5 (4.0 g, 7.4 μmol) was dissolved in ethyl acetate (2 mL), then Pd / C (5 mg) was added and the vessel was charged with hydrogen. The mixture was stirred for 1 h; then the catalyst was removed by filtration and the solvent was evaporated under vacuum. The resulting residue was purified by RP-HPLC to give Compound 6 (0.7 mg) as a pale yellow solid. MS: 450.1 [M+H] + 。

[0496] Example 6: Preparation of Antibody-Drug Conjugates

[0497] Conjugates were prepared using appropriate drug linkers and antibodies under the following conditions.

[0498] 55 mg of antibody in formulation buffer was adjusted in pH or buffer exchanged into a formulation of 5% (v / v) 0.5 M Tris, 0.025 M EDTA, pH 8.5 for reduction. 0.025 M EDTA was added in the formulation buffer to prevent metal-catalyzed disulfide reoxidation. 10 mM TCEP (7 equivalents per antibody) was added and incubated at 20 °C for 2 h to reduce the targeted number of interchain disulfide bonds and generate the average number of free thiols required per antibody. The free thiols were conjugated by adding a DMA solution of 20 mM drug linker (12 equivalents) and stirring at 20 °C for 1 h. Additional DMA solvent was added prior to adding the drug linker to maintain the solubility of the drug linker after addition and mixing was carried out using a stirring flask. Conjugation was terminated by adding an excess of NAC (10 mM) and stirring was continued for 30 min to quench unreacted maleimide. The ADC (yield 91 - 94%) was incubated with activated carbon at 15 rpm at room temperature for 1 h and / or filtered through to remove the excess quenched drug linker. The ADC was exchanged into the final formulation buffer (0.1 M Arg / PBS) using a Sephadex G-25 resin column and filtered through 0.2 μm PES, after which it was aliquoted and stored at ≤ -60 °C.

[0499] Example 7: Preparation of Antibody-Drug Conjugate (ADC)-1 Using Drug Linker 11 and UC-961

[0500] Prepare ADC-1 using Example 6 and the antibodies of drug linker 11 and UC-961.

[0501]

[0502] ; wherein the DAR value determined by RP-HPLC is 7.8.

[0503] Example 8: Preparation of Antibody-Drug Conjugate (ADC)-2 Using Drug Linker 13 and UC-961

[0504] Prepare ADC-2 using Example 6 and the antibodies of drug linker 13 and UC-961.

[0505]

[0506] ; wherein the DAR value determined by RP-HPLC is 7.7.

[0507] Example 9: Preparation of Antibody-Drug Conjugate (ADC)-3 Using Drug Linker 15 and UC-961

[0508] Prepare ADC-3 using Example 6 and the antibodies of drug linker 15 and UC-961.

[0509]

[0510] ; wherein the DAR value determined by RP-HPLC is 7.8.

[0511] Example 10: Preparation of Antibody-Drug Conjugate (ADC)-4 Using Drug Linker 18 and UC-961

[0512] Prepare ADC-4 using Example 6 and the antibodies of drug linker 18 and UC-961.

[0513]

[0514] ; wherein the DAR value determined by RP-HPLC is 7.8.

[0515] Example 11: Preparation of Antibody-Drug Conjugate (ADC)-5

[0516] Prepare ADC-5 using Example 6 and the antibody of UC-961.

[0517]

[0518] ; wherein the DAR value determined by RP-HPLC is 7.8.

[0519] Example 12: Preparation of antibody-drug conjugate (ADC)-6 using drug linker 15 and PTK-7 antibody

[0520] Prepare ADC-6 using Example 6 and drug linker 15 and PTK7 antibody.

[0521]

[0522] ; wherein the DAR value determined by RP-HPLC is 7.9.

[0523] Characterization of the conjugate

[0524] Example 13: Plasma stability

[0525] Plasma stability tests elucidated the stability of various ADCs in mouse and human plasma. The ADCs were tested in both mouse and human plasma.

[0526] Incubate the ADC in IgG-depleted plasma at a concentration of 50 μg / mL and a volume of 300 μL. Use a HiTRap Protein G column (Cytiva) for IgG depletion. Incubate the samples in Eppendorf tubes at 37 °C for time periods of 0, 1, 3, 7, and 15 days. After incubation for the appropriate time, transfer the samples to an -80 °C freezer until they can be processed. The samples are incubated twice at each time point.

[0527] To isolate the ADC from the plasma, mix 100 μL of each sample with 100 μL of Protein A magnetic bead slurry (Thermo Pierce) and 900 μL of sodium phosphate (50 mM, pH 7), and shake at room temperature for two hours. Then the ADC should bind to the beads, allowing the excess plasma to be discarded. Then wash the beads with 1 mL of 0.1% Triton, 0.1% IPA to remove non-specific binding, and then wash twice in 1 mL of PBS for 30 minutes each time with shaking. Then, elute the ADC from the beads in 100 μL of low pH, high organic mixture (40 mM glycine, 2% formic acid, 50% acetonitrile) for 60 minutes. Then centrifuge the bead slurry and inject 50 μL of the supernatant into LC-MS.

[0528] LC uses a 50 mm x 2.1 bioZen XB-C8 column with a gradient of H2O and acetonitrile (each with 0.1% formic acid) over seven minutes. MS operates in the intact protein mode, where the source temperature is 500 °C, the extinction voltage is 200 V, and the mass range is 900 - 4500 m / z.

[0529] The processing was carried out in Sciex OS and the stability results of mouse plasma are as shown in Figure 1 and the stability results of human plasma are as shown in Figure 2 .

[0530] Example 14: Cell Binding

[0531] The ability of the ADC to bind to Jeko-1 cells was measured using an in vitro cell binding assay.

[0532] For each Jeko-1 cell line, 500,000 cells were plated in each well of a 96-well deep-well plate (Thermo Scientific #249946) at 50 μL per well. Starting from a 1-μg / mL stock solution, a 1:3 dilution series of the primary antibody was prepared. Subsequently, 50 μL of different concentrations of the primary antibody (final concentrations ranging from 17 pg / mL to 1000 ng / mL) was placed in 50 μL containing the cells. The cells and the antibody were mixed and incubated on ice for 20 minutes. For the first wash: 300 μL of FACS buffer was added and centrifuged at 500×g for 5 minutes at 4 °C. The supernatant was discarded and the cells were resuspended in 400 μL of FACS buffer for additional washes. After the second wash, the cells were resuspended in 100 μL of goat anti-human IgG secondary antibody phycoerythrin (PE) (ThermoFisher Scientific #12-4998-82) at a final concentration of 1 μg / mL and incubated on ice (in the dark) for 20 minutes. The cells were washed twice as previously described and analyzed on a BD FACSVerse using Flowjo software (version 10). The maximum binding percentage relative to the highest concentration was plotted and the half-maximal effective concentration (EC 50 ) value was determined using GraphPad Prism (version 7).

[0533] Example 15: Cytotoxicity Measurement

[0534] The ability of Compounds 4 and 6 to inhibit cell growth was measured using an in vitro cytotoxicity assay.

[0535] The cells were cultured in the logarithmic growth phase and seeded into 96-well plates. Each cell line was seeded at slightly different concentrations, but in the range of 5x10 3 to 50x10 4 cells / well. The cells were incubated in duplicate with a 3-fold serial dilution of a specific immunoconjugate starting at 3000 or 1000 nanomoles (3000, 1000, 333, 111, 37, 12.3, 4.1, 1.37, 0.46, 0.15 nanomoles) at 37 °C and 5% CO2 for 72 hours. After treatment, the cells were mixed with an equal volume of The reagent (Promega Inc.) was incubated at room temperature for 15 minutes, and the viability was determined using a photometer. The EC50 values of the breast cancer cell line SKBR3 are shown in Table 1.

[0536] Table 1.

[0537] Compound # EC50 in SKBR3 Cells 4 3.8 nM 6 22 nM

[0538] Example 16: Internalization

[0539] MDA-MB-468 cells were harvested, washed with cold PBS, and resuspended in cold FACS buffer (containing PBS and 2% FBS) at a concentration of 1×10 7 cells / mL. Aliquots of 1×10 6 cells were added to microcentrifuge tubes or wells. The primary antibody was diluted to produce 10-fold stock solutions of 300 μg / mL or 1 mg / mL to allow 10 μl of each solution to be added to the appropriate tubes.

[0540] The control group consisted only of unstained secondary antibody (goat anti-human IgG-PE, Fc-γ specific)

[0541] (Thermo Fisher Scientific #12-4998-82). The test groups contained cells treated under the following conditions and were evaluated with primary antibody at 30 μg / mL (203 nM) or 100 μg / mL (676 nM) according to the experiment: except for the control, the cells were placed on ice for 20 minutes, the control group was centrifuged at 300×g for 4 minutes, washed twice with 200 μl of FACS buffer, resuspended in 100 μl of FACS buffer, and incubated at 37 °C for 30, 60, 120, or 240 minutes. After incubation, the cells were centrifuged at 250×g, washed twice with FACS buffer, and resuspended in 100 μl of FACS buffer. The 10-fold secondary antibody stock solution was diluted 1:2000 in FACS buffer, and 10 μl of each was added to the appropriate tubes. The cells were incubated on ice for 20 minutes, washed twice with FACS buffer, and resuspended in 100 μl of fixation buffer (4% paraformaldehyde in PBS). Then, FACS analysis was performed to evaluate the median fluorescence intensity (MFI). The relative extent of primary antibody internalization was determined by comparing the MFI values at each time point with the MFI value of the primary antibody control at time 0.

[0542] Example 17: DAR by RP-HPLC

[0543] The drug-to-antibody ratio (DAR) of each ADC was determined using RP-HPLC of the ADC. As shown in Table 2 below, reverse-phase HPLC was used to obtain the DAR and monomer content of the ADC.

[0544] RP-HPLC conditions: Column – Phenomenex Kinetex 50 x 4.6 mm, 2.6 μm, part number: PL1912-1502. MPA – 0.1% TFA / H20, MPB – 0.1% TFA / CAN

[0545] Method: Flow rate – 1 mL / min, gradient – see Table 3. Column temperature – 50 °C.

[0546] Sample temperature – RT. DAD 214 nm, BW 16 nm; reference 440 nm, BW 80 nm; peak width > 0.4 min (8 s response time (0.62 Hz); spectrum: 200 – 600 nm, step size 1.2 nm, slit 8 nm.

[0547] Sample – pure injection, ~5 μg.

[0548] Table 2: Monomer content and DAR of various ADCs

[0549] ADC Monomer (%) DAR ADC - 1 96 7.8 ADC - 2 94 7.7 ADC - 3 97 7.8 ADC - 4 97 7.8 ADC - 5 97 7.8 ADC - 6 98 7.9

[0550] Table 3: Flow rate gradient of RP-HPLC method

[0551] Time (min) B％ 0 30 2 30 10 41 11.5 90 15.5 90 16.5 30 20 30

[0552] Example 18: In vivo efficacy

[0553] The anti-tumor activity of the ADC was evaluated in Jeko-1 mantle cell lymphoma and SK-OV3 ovarian tumor xenograft models. Tumor-bearing mice were randomly grouped based on their individual tumors and given iv injection doses. As Figure 3 shown, at an iv injection dose of 10 mg / Kg once a week for 3 weeks (days 1, 8, 15), the ADC showed anti-tumor activity in the Jeko-1 model. And as Figure 4 shown, at an iv injection dose of 20 mg / Kg once a week for 4 weeks (days 1, 8, 15, 22), ADC-3 showed anti-tumor activity in the SK-OV3 model.

Claims

1. A compound of formula (I): or a pharmaceutically acceptable salt thereof, wherein; R 1 selected from -O-CH2-CH2-O- and -NH-C(O)-CH2-O-; L is L 2 -(L 2B ) z -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ; L 2 selected from C 1-6 alkylene; L 2B selected from NR 4 C(O)O-C 1-6 alkylene-phenylene, wherein said phenylene is optionally substituted with one or more R 5 substituents; L 3 Residues selected from residues of 1 to 7 amino acids; L 4 Selected from optionally substituted C 1-6 alkylene, wherein said C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl; L 5 Selected from (O-CH2-CH2-) q -(NR 3 ) s ; L 6 Selected from optionally substituted C 1-6 alkylene, wherein said C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl; L 7 Selected from C 5-6 carbocyclic olefins; R 2 selected from optionally substituted 5- to 6-membered heterocycles, wherein the 5- to 6-membered heterocycle is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl; R 3 selected from hydrogen and C 1-6 alkyl; R 4 selected from hydrogen and optionally C 1-6 alkyl substituted by one or more SO2C 1-6 alkyl groups; Each R 5 is independently selected from sugar; m is selected from 0 and 1; n is selected from 0 and 1; p is selected from 0 and 1; q is selected from 0 to 8; s is selected from 0 and 1; and z is selected from 0 and 1.

2. The compound or salt according to claim 1, wherein formula (I) is represented as or a pharmaceutically acceptable salt thereof.

3. The compound or salt according to claim 1, wherein formula (I) is represented as or a pharmaceutically acceptable salt thereof.

4. The compound or salt according to any one of claims 1 to 3, wherein L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ; 5. The compound or salt according to any one of claims 1 to 4, wherein L is L 2 -L 3 -L 4 -R 2 .

6. The compound or salt according to any one of claims 1 to 4, wherein L is L 2 -L 3 -L 4 -L 7 -R 2 .

7. The compound or salt according to any one of claims 1 to 4, wherein L is L 2 -L 3 -L 4 -L 5 -L 6 -L 7 -R 2 .

8. The compound or salt according to any one of claims 1 to 4, wherein L is L 2 -L 2B -L 3 -L 4 -R 2 ; 9. The compound or salt according to any one of claims 1 to 8, wherein L 2 is a C1 alkylene group.

10. The compound or salt according to any one of claims 1 to 9, wherein L 3 is selected from residues comprising 1 to 5 amino acids.

11. The compound or salt according to any one of claims 1 to 10, wherein the amino acid is a natural amino acid.

12. The compound or salt according to any one of claims 1 to 11, wherein the amino acid is selected from α - amino acids and β - amino acids.

13. The compound or salt according to claim 12, wherein the amino acid is selected from alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, citrulline, sarcosine, and β - alanine.

14. The compound or salt according to any one of claims 1 to 13, wherein L 3 said amino acid of is selected from glycine and phenylalanine.

15. The compound or salt according to any one of claims 1 to 14, wherein L 3 the residue of contains 4 amino acids.

16. The compound or salt according to any one of claims 1 to 15, wherein the residue of L 3 comprises at least two different amino acids.

17. A compound or salt according to any one of claims 1 to 16, wherein L 3 is 18. The compound or salt according to claim 13, wherein L 3 said amino acid of is selected from sarcosine.

19. The compound or salt according to claim 18, wherein L 3 the residue of which comprises 1 amino acid.

20. The compound or salt according to claim 19, wherein L 3 is 21. The compound or salt according to claim 1 or 8, wherein L 2B is selected from NR 4 C(O)O-C1-alkylene-phenyl, wherein the phenyl is substituted with one R 5 substituent.

22. The compound or salt according to claim 21, wherein R 5 is 23. The compound or salt according to any one of claims 1 to 22, wherein L 4 is selected from 24. The compound or salt according to any one of claims 1 to 23, wherein L 4 is selected from -C(O)-(CH2)2- and -C(O)-(CH2)5-.

25. A compound or salt according to claim 1, 4 or 7, wherein L 5 is -(O-CH2-CH2-)4-NH-.

26. The compound or salt according to claim 1, 4, 7 or 25, wherein L 6 is selected from 27. The compound or salt according to claim 1, 4, 7 or 26, wherein L 6 is selected from -C(O)-(CH2)2- and -C(O)-(CH2)5-.

28. The compound or salt according to claim 27, wherein L 6 is selected from -C(O)-(CH2)2-.

29. A compound or salt according to any one of claims 1, 4, 6 or 7, wherein L 7 is phenylene.

30. The compound or salt according to any one of claims 1 to 29, wherein R 2 is selected from optionally substituted 5-membered heterocycles.

31. The compound or salt according to claim 30, wherein R 2 is 32. The compound or salt according to claim 1, wherein the compound is selected from or a pharmaceutically acceptable salt of any of them.

33. The compound or salt according to claim 1, wherein the compound is selected from or a pharmaceutically acceptable salt of any of them.

34. The compound or salt according to claim 1, wherein the compound is selected from or a pharmaceutically acceptable salt of any of them.

35. The compound or salt according to claim 1, wherein R 1 selected from -O-CH2-CH2-O-; L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ; L 2 selected from C 1-6 alkylene; L 3 Selected from residues comprising 3 to 5 amino acids; L 4 selected from L 5 selected from (O-CH2-CH2-) q -(NR 3 ) s ; L 6 selected from L 7 is a phenylene group; R 2 selected from maleimide; R 3 Selected from hydrogen and C 1-6 alkyl; m is selected from 0 and 1; n is selected from 0 and 1; p is selected from 0 and 1; q is selected from 2 to 6; and s is selected from 0 and 1.

36. The compound or salt according to claim 1 or 35, wherein R 1 is selected from -O-CH2-CH2-O-; L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ; L 2 is L 3 is L 4 selected from L 5 is m is selected from 0 and 1; L 6 is n is selected from 0 and 1; L 7 is p is selected from 0 and 1; R 2 is 37. The compound or salt according to claim 1 or claims 35 to 36, wherein R 1 is selected from -O-CH2-CH2-O-; L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ; L 2 is L 3 is L 4 selected from L 5 is m is selected from 0 and 1; L 6 is n is selected from 0 and 1; L 7 is p is selected from 0 and 1; R 2 is 38. The compound or salt according to any one of claims 1 to 37, further comprising a ligand (Lg).

39. The compound or salt according to any one of claims 1 to 37, wherein the compound or salt is further modified with a ligand.

40. The compound or salt according to any one of claims 38 to 39, wherein the compound or salt is covalently attached to a ligand.

41. The compound or salt according to any one of claims 38 to 40, wherein the compound or salt reacts with the ligand to form a covalent bond.

42. The compound or salt according to any one of claims 38 to 41, wherein the ligand is selected from an antibody or an antigen - binding fragment thereof.

43. The compound or salt according to any one of claims 38 to 42, wherein formula (I) is represented as or a pharmaceutically acceptable salt thereof, wherein; Lg is the ligand.

44. A compound of formula (III): or a pharmaceutically acceptable salt thereof, wherein; Lg is a ligand; R 1 selected from -O-CH2-CH2-O- and -NH-C(O)-CH2-O-; L is L 2 -(L 2B ) z -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ; L 2 Selected from C 1-6 alkylene; L 2B selected from NR 4 C(O)O-C 1-6 alkylene-phenylene, wherein said phenylene is optionally substituted with one or more R 5 substituted; L 3 Residues selected from residues of 1 to 7 amino acids; L 4 selected from optionally substituted C 1-6 alkylene, wherein said C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl; L 5 selected from -(O-CH2-CH2)- q -(NR 3 ) s -; L 6 selected from optionally substituted C 1-6 alkylene, wherein said C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl; L 7 Selected from C 5-6 carbocyclic ring; R 2 selected from optionally substituted 5- to 6-membered heteroalkenes, wherein the 5- to 6-membered heteroalkene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl; R 3 selected from hydrogen and C 1-6 alkyl; R 4 selected from C alkyl optionally substituted with one or more SO2C 1-6 alkyl 1-6 alkyl; Each R 5 is independently selected from sugar; m is selected from 0 and 1; n is selected from 0 and 1; p is selected from 0 and 1; q is selected from 0 to 8; s is selected from 0 and 1; and z is selected from 0 and 1.

45. The compound or salt according to claim 44, wherein R 1 is -O-CH2-CH2-O-.

46. The compound or salt according to claim 44, wherein R 1 is -NH-C(O)-CH2-O-.

47. The compound or salt according to any one of claims 44 to 46, wherein formula (III) is represented as or a pharmaceutically acceptable salt thereof.

48. The compound or salt according to any one of claims 44 to 46, wherein L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 .

49. The compound or salt according to any one of claims 44 to 46, wherein L is L 2 -L 3 -L 4 -R 2 .

50. A compound or salt according to any one of claims 44 to 46, wherein L is L 2 -L 3 -L 4 -L 7 -R 2 .

51. The compound or salt according to any one of claims 44 to 46, wherein L is L 2 -L 3 -L 4 -L 5 -L 6 -L 7 -R 2 .

52. The compound or salt according to any one of claims 44 to 46, wherein L is L 2 -L 2B -L 3 -L 4 -R 2 .

53. The compound or salt according to any one of claims 44 to 52, wherein L 2 is a C1 alkylene group.

54. The compound or salt according to any one of claims 44 to 53, wherein L 3 is selected from residues containing from 1 to 5 amino acids.

55. The compound or salt according to any one of claims 44 to 54, wherein L 3 is selected from residues comprising 3 to 5 amino acids.

56. The compound or salt according to any one of claims 44 to 55, wherein the amino acid is a natural amino acid.

57. The compound or salt according to any one of claims 44 to 56, wherein the amino acid is selected from α - amino acids and β - amino acids.

58. A compound or salt according to any one of claims 44 to 57, wherein the amino acid is selected from alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, citrulline, sarcosine, and β-alanine.

59. The compound or salt according to any one of claims 44 to 58, wherein L 3 said amino acid is selected from glycine and phenylalanine.

60. The compound or salt according to any one of claims 44 to 59, wherein L 3 has 4 amino acids for the residue of 61. The compound or salt according to any one of claims 44 to 60, wherein the residue of L 3 comprises at least two different amino acids.

62. The compound or salt according to any one of claims 44 to 61, wherein L 3 is 63. The compound or salt according to claim 58, wherein L 3 The amino acid is selected from sarcosine.

64. The compound or salt according to claim 63, wherein L 3 the residue of contains 1 amino acid.

65. The compound or salt according to claim 64, wherein L 3 is 66. The compound or salt according to claim 1 or 52, wherein L 2B is selected from NR 4 C(O)O-C1 alkylene-phenylene, wherein the phenylene is substituted by one R 5 substituent.

67. The compound or salt according to claim 66, wherein R 5 is 68. A compound or salt according to any one of claims 44 to 67, wherein L 4 is selected from 69. A compound or salt according to any one of claims 44 to 68, wherein L 4 is selected from -C(O)-(CH2)2- and -C(O)-(CH2)5-.

70. The compound or salt according to claim 44 or 51, wherein L 5 is -(O-CH2-CH2-)4-NH-.

71. The compound or salt according to claim 44, 51 or 70, wherein L 6 is selected from 72. The compound or salt according to claim 44 or 71, wherein L 6 is selected from -C(O)-(CH2)2- and -C(O)-(CH2)5-.

73. A compound or salt according to claim 44, 51 or 70 - 72, wherein L 6 is selected from -C(O)-(CH2)2-.

74. The compound or salt according to any one of claims 1, 50 or 51, wherein L 7 is a phenylene group.

75. A compound or salt according to any one of claims 1 to 2, wherein R 1 selected from -O-CH2-CH2-O-; L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ; L 2 Selected from C 1-6 alkylene; L 3 Residues selected from those containing 3 to 5 amino acids; L 4 selected from L 5 selected from (O-CH2-CH2-) q -(NR 3 ) s ; L 6 selected from L 7 is a phenylene group; R 2 selected from maleimide; R 3 Selected from hydrogen and C 1-6 alkyl; m is selected from 0 and 1; n is selected from 0 and 1; p is selected from 0 and 1; q is selected from 2 to 6; and s is selected from 0 and 1.

76. A compound or salt according to any one of claims 1 to 2 or 75, wherein R 1 is selected from -O-CH2-CH2-O-; L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ; L 2 Yes L 3 is L 4 selected from L 5 is m is selected from 0 and 1; L 6 is n is selected from 0 and 1; L 7 selected from p is selected from 0 and 1; R 2 is 77. A compound or salt according to any one of claims 1 to 2 or 75 to 76, wherein R 1 selected from -O-CH2-CH2-O-; L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ; L 2 is L 3 Yes L 4 selected from L 5 is m is selected from 0 and 1; L 6 is n is selected from 0 and 1; L 7 is p is selected from 0 and 1; R 2 Yes 78. A compound or salt according to claim 44, wherein the compound is represented by formula (V- A) or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1 - 8. The compound or salt according to claim 44, wherein the compound is represented by formula (V-B) or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1 - 8.

80. A compound or salt according to claim 44, wherein the compound is represented by formula (V-C): or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1 - 8.

81. A compound or salt according to claim 44, wherein the compound is represented by formula (V-D) or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1 - 8.

82. A compound or salt according to claim 44 or 78, wherein the compound is selected from: or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1 - 8.

83. A compound or salt according to claim 44 or 79, wherein the compound is selected from: or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1 - 8.

84. A compound or salt according to claim 44 or 80, wherein the compound is selected from: or a pharmaceutically acceptable salt thereof, wherein the DAR is selected from about 1 - 8.

85. A compound or salt according to any one of claims 44 to 81, wherein the ligand is selected from an antibody or an antigen-binding fragment thereof.

86. A compound or salt according to claim 85, wherein the ligand is selected from chimeric antibodies, humanized antibodies, and fully human antibodies.

87. A compound or salt according to claim 85, wherein the antibody or an antigen-binding fragment thereof binds to an antigen selected from the group consisting of or comprising CD19, CD20, CD22, CD30, CD37, CD79b, HER2, and PSMA.

88. A compound or salt according to claim 85, wherein the antibody or an antigen-binding fragment thereof binds to HER2.

89. A compound or salt according to claim 85, wherein the antibody or an antigen-binding fragment thereof is selected from UC-961, PTK-7, trastuzumab, vedotin, loncastuximab, rosopatuximab, rituximab, pinatuzumab, polatuzumab, and necitumumab.

90. A compound or salt according to claim 85, wherein the antibody is trastuzumab.

91. A compound of formula (IV): or a pharmaceutically acceptable salt thereof.

92. A pharmaceutical composition comprising the compound or salt according to any one of claims 1 to 91 and a pharmaceutically acceptable excipient.

93. Use of the compound or salt according to any one of claims 1 to 91 or the pharmaceutical composition according to claim 92 in the treatment of a disease or disorder.

94. Use of the compound or salt according to any one of claims 1 to 91 or the pharmaceutical composition according to claim 92 in the treatment of tumors.

95. Use of the compound or salt according to any one of claims 1 to 91 or the pharmaceutical composition according to claim 92 in the treatment of cancer.

96. A method of treating a subject suffering from a disease or disorder, comprising administering to the subject in need thereof the compound or salt according to any one of claims 1 to 91 or the pharmaceutical composition according to claim 92.

97. A method of treating a subject suffering from a tumor, comprising administering to the subject in need thereof the compound or salt according to any one of claims 1 to 91 or the pharmaceutical composition according to claim 92.

98. A method of treating a subject suffering from cancer, comprising administering to the subject in need thereof the compound or salt according to any one of claims 1 to 91 or the pharmaceutical composition according to claim 92.

99. The method according to claim 95 or 98, wherein the cancer is selected from lung cancer, kidney cancer, urethral cancer, colorectal cancer, prostate cancer, glioblastoma multiforme, ovarian cancer, pancreatic cancer, breast cancer, melanoma, liver cancer, bladder cancer, gastric cancer and esophageal cancer.

100. A compound of formula (I*): or a pharmaceutically acceptable salt thereof, wherein; L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ; L 2 selected from C 1-6 alkylene; L 3 Selected from residues comprising 1 to 7 amino acids; L 4 Selected from optionally substituted C 1-6 alkylene, wherein said C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl; L 5 selected from (O-CH2-CH2-) q -(NR 3 ) s ; L 6 selected from optionally substituted C 1-6 alkylene, wherein said C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl; L 7 Selected from C 5-6 carbocyclic olefins; R 2 selected from optionally substituted 5- to 6-membered heterocycles, wherein the 5- to 6-membered heterocycles are optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl; R 3 selected from hydrogen and C 1-6 alkyl group; m is selected from 0 and 1; n is selected from 0 and 1; p is selected from 0 and 1; q is selected from 0 to 8; and s is selected from 0 and 1.

101. The compound or salt according to claim 100, wherein formula (I)* is represented as or a pharmaceutically acceptable salt thereof.

102. A compound or salt according to any one of claims 100 to 101, wherein L is L 2 -L 3 -L 4 -R 2 .

103. The compound or salt according to any one of claims 100 to 101, wherein L is L 2 -L 3 -L 4 -L 7 -R 2 .

104. The compound or salt according to any one of claims 100 to 101, wherein L is L 2 -L 3 -L 4 -L 5 -L 6 -L 7 -R 2 .

105. The compound or salt according to any one of claims 100 to 104, wherein L 2 is a C1 alkylene group.

106. The compound or salt according to any one of claims 100 to 105, wherein L 3 is selected from residues comprising 1 to 5 amino acids.

107. The compound or salt according to any one of claims 100 to 106, wherein the amino acid is a natural amino acid.

108. The compound or salt according to any one of claims 100 to 107, wherein the amino acid is selected from α-amino acids and β-amino acids.

109. The compound or salt according to claim 108, wherein the amino acid is selected from alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, citrulline, sarcosine and β-alanine. The compound or salt according to any one of claims 100 to 109, wherein L 3 said amino acid is selected from glycine and phenylalanine. The compound or salt according to any one of claims 100 to 110, wherein the residue of L 3 comprises 4 amino acids.

112. The compound or salt according to any one of claims 100 to 111, wherein the residue of L 3 comprises at least two different amino acids.

113. The compound or salt according to any one of claims 100 to 112, wherein L 3 is 114. The compound or salt according to any one of claims 100 to 113, wherein L 4 is selected from -C(O)-(CH2)2- and -C(O)-(CH2)5-.

115. The compound or salt according to claim 100 or 104, wherein L 5 is -(O-CH2-CH2-)4-NH-.

116. The compound or salt according to claim 100 or 104, wherein L 6 is selected from -C(O)-(CH2)2- and -C(O)-(CH2)5-.

117. The compound or salt according to claim 116, wherein L 6 is selected from -C(O)-(CH2)2-.

118. The compound or salt according to any one of claims 100 or 117, wherein L 7 is phenylene.

119. The compound or salt according to any one of claims 100 to 118, wherein R 2 is selected from optionally substituted 5-membered heterocycles.

120. The compound or salt according to claim 119, wherein R 2 is 121. The compound or salt according to any one of claims 100 to 120, wherein L is selected from or a pharmaceutically acceptable salt of any one thereof.

122. The compound or salt according to claim 100 or 121, wherein the compound is selected from or a pharmaceutically acceptable salt of any of them.

123. The compound or salt according to any one of claims 100 to 122, further comprising a ligand.

124. The compound or salt according to any one of claims 100 to 123, wherein the compound or salt is further modified by a ligand.

125. The compound or salt according to any one of claims 100 to 124, wherein the compound or salt is covalently attached to a ligand.

126. A compound or salt according to any one of claims 100 to 125, wherein the compound or salt reacts with a ligand to form a covalent bond.

127. A compound or salt according to any one of claims 100 to 126, wherein formula (I)* is represented as or a pharmaceutically acceptable salt thereof, wherein; Lg is the ligand.

128. A compound of formula (IV)*: or a pharmaceutically acceptable salt thereof, wherein; Lg is a ligand; L is L 2 -L 3 -L 4 -(L 5 ) m -(L 6 ) n -(L 7 ) p -R 2 ; L 2 selected from C 1-6 alkylene; L 3 a residue selected from residues of from 1 to 7 amino acids; L 4 selected from optionally substituted C 1-6 alkylene, wherein said C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl; L 5 selected from (O-CH2-CH2-) q -(NR 3 ) s ; L 6 selected from optionally substituted C 1-6 alkylene, wherein said C 1-6 alkylene is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl; L 7 Selected from C 5-6 carbocyclic olefins; R 2 selected from optionally substituted 5- to 6-membered heterocycles, wherein the 5- to 6-membered heterocycle is optionally substituted by one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, oxo, C 1-10 alkyl, -C 1-10 haloalkyl, -O-C 1-10 alkyl, C 2-10 alkenyl, C 2-10 alkynyl; R 3 selected from hydrogen and C 1-6 alkyl; m is selected from 0 and 1; n is selected from 0 and 1; p is selected from 0 and 1; q is selected from 0 to 8; and s is selected from 0 and 1.

129. A compound or salt according to any one of claims 127 to 128, wherein the ligand is selected from an antibody or an antigen-binding fragment thereof.

130. A compound or salt according to claim 129, wherein the ligand is selected from chimeric antibodies, humanized antibodies, and fully human antibodies.

131. A compound or salt according to claim 129, wherein the antibody or antigen-binding fragment thereof binds to an antigen selected from the group consisting of or consisting of CD19, CD20, CD22, CD30, CD37, CD79b, HER2, and PSMA.

132. A compound or salt according to claim 131, wherein the antibody or antigen-binding fragment thereof binds to HER2.

133. A compound or salt according to claim 129, wherein the antibody or antigen-binding fragment thereof is selected from trastuzumab, brentuximab vedotin, loncastuximab tesirine, rosopatuximab, rituximab, pinatuzumab, polatuzumab vedotin, and necitumumab.

134. A compound or salt according to claim 133, wherein the antibody is trastuzumab.

135. A compound or salt according to claim 133, wherein the ligand is UC-961.

136. A pharmaceutical composition comprising a compound or salt according to any one of claims 100 to 135 and a pharmaceutically acceptable excipient.

137. Use of a compound or salt according to any one of claims 100 to 135 or the pharmaceutical composition according to claim 136 in the treatment of a disease or disorder.

138. Use of a compound or salt according to any one of claims 100 to 135 or the pharmaceutical composition according to claim 136 in the treatment of a tumor.

139. Use of a compound or salt according to any one of claims 100 to 135 or the pharmaceutical composition according to claim 136 in the treatment of cancer.

140. A method of treating a subject suffering from a disease or disorder, comprising administering to the subject in need thereof a compound or salt according to any one of claims 100 to 135 or the pharmaceutical composition according to claim 136.

141. A method of treating a subject suffering from a tumor, comprising administering to the subject in need thereof a compound or salt according to any one of claims 100 to 135 or the pharmaceutical composition according to claim 136.

142. A method of treating a subject having cancer, comprising administering to the subject in need thereof a compound or salt according to any one of claims 100 to 135 or a pharmaceutical composition according to claim 136.

143. The method according to claim 139 or 142, wherein the cancer is selected from lung cancer, kidney cancer, urethral cancer, colorectal cancer, prostate cancer, glioblastoma multiforme, ovarian cancer, pancreatic cancer, breast cancer, melanoma, liver cancer, bladder cancer, gastric cancer and esophageal cancer.

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