Conjugates of Anti-PTK7 antibodies

Abstract

Provided herein is a conjugate of Formula (XX): or a pharmaceutically acceptable salt thereof, wherein L is a Targeting Unit, wherein the Targeting Unit is an anti-PTK7 antibody or an antigen-binding portion thereof, and wherein the variables of Formula (XX) are as defined in the application. Such compounds can be useful as anti-cancer agents.

Description

CONJUGATES OF ANTI-PTK7 ABTIBODIESCROSS-REFERENCE

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 640,733 filed on April 30, 2024, and U.S. Provisional Patent Application No. 63 / 722,553 filed on November 19, 2024, the entire contents of each of which are incorporated herein by reference.BACKGROUND

[0002] Protein tyrosine kinase 7 (PTK7), also known as colon carcinoma kinase 4 (CCK.4), is a receptor tyrosine kinase involved in non-canonical Wnt signaling and was first identified as a gene upregulated in colon cancer cells. PTK belongs to the Wnt ligand binding receptor family whose other members include receptor tyrosine kinase-like orphan receptors 1 (ROR1) and 2 (ROR2). and receptor tyrosine kinase RYK. Members of this receptor family are transmembrane proteins that are void of kinase activity. PTK7 plays roles in embryonic development, maintenance of tissue homeostasis, and stem cell signaling; however, expression of PTK7 is absent or minimal in differentiated healthy adult tissues. Overexpression of PTK7 has been reported in a variety of cancers including head and neck cancer, non-small cell lung cancer (NSCLC), triple-negative breast cancer (TNBC), bladder cancer, and ovarian cancer. In this milieu, PTK7 promotes cell survival, migration, and invasion, and chemotherapy resistance.

[0003] PTK7 expression has been associated with poor prognosis and higher metastatic potential in patients with various cancers, and thus represents a promising therapeutic target. In view of PTK7’s critical role in tumor progression, there is a need for new and improved cancer immunotherapies that target PTK7.SUMMARY OF THE INVENTION

[0004] The present disclosure provides antibody-drug conjugates that bind specifically to PTK7. Drug-linkers are conjugated to an anti-PTK7 antibody or an antigen-binding portion thereof to form antibody-drug conjugates that target PTK7 and ultimately release a payload of choice (e.g., exatecan) to treat a PTK7 -positive cancer. To this end, the present invention provides novel antibody-drug conjugates that target PTK7-positive cancers. The disclosed anti- PTK7 antibody-drug conjugates can exert a clinically useful cytotoxic effect on PTK7 expressing tumor cells without exerting undesirable effects on non-PTK7 expressing cells.

[0005] In an aspect, the present disclosure provides a Drug-Uinker of Formula (X):Formula (X) or a pharmaceutically acceptable salt thereof, wherein;D is a Drug unit;Y1is absent or selected from -O-T1and -NH-T2;T1is a sugar cleavable unit;T2is a peptide cleavable unit;51is selected from: (i) an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(0)2- - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, - C(O)O-, -S-, — S(O)~ , -S(O)2-, 5- to 6-membered heterocyclene. or -P(O)(R20)2-; (ii) optionally substituted C3-C30 alkenylene, wherein one or more alkenylene units of the C3-C30 alkenylene are optionally and independently replaced by -N(R20)-, -N(R20)C(O)-, - C(O)N(R20) , N(R20)S(O)2, S(O)2N(R20) , O , C(O) , OC(O) , C(O)O , S , S(O , -S(O)2-, or -P(O)(R20)2; (iii) one or more amino acid(s); (iv) one or more N-substituted amino acid(s); (v) optionally substituted poly ether; (vi) optionally substituted C3-C10 carbocyclene; (vii) optionally substituted 5- to 10-membered heterocyclene;52is selected from an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(O)2- - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, - C(O)O- -S-, — S(O)~ , — S(O)2— , 5- to 6-membered heterocyclene. or -P(O)(R20)2-;53is selected from a spacer, wherein S3is present or absent; wherein the optional substituents on M1, K1, S1, S2, and S3, are independently selected at each occurrence from:(i) halogen. -OR30, -N(R30)2, -SR30, -N(R30)2, -C(O)R30, -C(O)N(R30)2, - N(R30)C(O)R30. -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O- S(O)2OR30, -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =S, =N(R30), and -CN;(ii) Ci-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30. -SR30, -N(R30)2, -C(O)R30. - C(O)N(R30)2, -N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O- S(O)2OR30, -P(O)(OR30)2, -OP(O)(OR30)2, -N02, =0, =S, =N(R30), -CN, C3-10 carbocycle and 3- to 10-membered heterocycle; and(iii) C3-10 carbocycle and 3- to 10-membered heterocycle each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, - N(R30)2, -C(O)R30, -C(0)N(R30)2, -N(R30)C(0)R30-C(O)OR30, -OC(O)R30, -S(O)R30, - S(O)2R30, -P(O)(OR30)2, -OP(0)(OR30)2. -NO2, =0, =S, =N(R30), -CN, Ci-6alkyl, C2-6 alkenyl, and C2-6 alkynykM1is a group which can react with a ligand to form a connector unit;K1is selected from:(i) a peptide unit,(ii) an oligosaccharide; and(iii) a poly ether; each R20is independently selected from hydrogen; and C1-6 alky l, C2-6 alkenyl, C2-6 alkynyl, C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen. -OH. -CN, -NO2, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl. -O-Ci-10 alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle; and each R30is independently selected from hydrogen; and C1-6 alky l, C2-6 alkenyl, C2-6 alkynyl, C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen. -OH. -CN. -NO2, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl, -O-Ci-10 alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle.

[0006] In an aspect, the present disclosure provides a conjugate of the Formula (XX):Formula (XX) or a pharmaceutically acceptable salt thereof, wherein;L is a Targeting Unit, wherein the Targeting Unit is an anti-PTK7 antibody or an antigen-binding portion thereofD is a Drug unit;Y1is absent or selected from -O-T1and -NH-T2;T1is a sugar cleavable unit;T2is peptide cleavable unit;S1is selected from: (i) an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkydene are optionally and independently replaced by -N(R20)-, - N(R20)C(O) , -C(O)N(R20)-, -N(R20)S(O)2-, - S(O)2N(R20)-, O , C(O) , -OC(O)-, -C(0)0- -S-, — S(0)~ , -S(0)2- 5- to 6-membered heterocyclene, or -P(O)(R20)2-; (ii) optionally substituted C3-C30 alkenylene, wherein one or more alkenylene units of the C3- C30 alkenylene are optionally and independently replaced by -N(R20)-, -N(R20)C(O)-, - C(O)N(R20)-, -N(R20)S(O)2- - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, -C(O)O- -S-, -S(O)-. -S(O)2- or -P(O)(R20)2: (iii) one or more amino acid(s); (iv) one or more N-substituted amino acid(s); (v) optionally substituted poly ether; (vi) optionally substituted C3-C10 carbocyclene; (vii) optionally substituted 5- to 10-membered heterocyclene;52is selected from an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(0)2- - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, - C(O)O-, -S-, -S(O)-, -S(O)2- 5- to 6-membered heterocyclene, or -P(O)(R20)2-;53is selected from a spacer, wherein S3is present or absent; wherein the optional substituents on M1, K1, S1, S2, and S3, are independently selected at each occurrence from:(i) halogen, -OR30, -N(R30)2, -SR30, -N(R30)2, -C(O)R30, -C(O)N(R30)2, - N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O- S(O)2OR30, -P(O)(OR30)2, -OP(0)(OR30)2. -NO2, =0, =S, =N(R30), and -CN;(ii) Ci-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, -N(R30)2, -C(O)R30, - C(O)N(R30)2, -N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O- S(O)2OR30, -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =S, =N(R30), -CN, C3-10 carbocycle and 3- to 10-membered heterocycle; and(iii) C3-10 carbocycle and 3- to 10-membered heterocycle each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, - -S(O)R30, -alkyl, C2-6 alkenyl, and C2-6 alkynyl;M2is a connector unit;K1is selected from:(i) a peptide unit,(ii) an oligosaccharide; and(iii) a polyether; each R20is independently selected from hydrogen; and C1-6 alkyd, C2-6 alkenyl, C2-6 alkynyl. C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen. -OH. -CN, -NO2, -NH2, -N(CI-6 alkyl)2, Ci-io alkyl, -Ci-io haloalkyl, -O-Ci-io alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle; and each R?ois independently selected from hydrogen; and C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen. -OH. -CN. -NO2, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl, -O-Ci-10 alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle.

[0007] In some embodiments, for a conjugate or salt of Formula (XX), L is an anti-PTK7 antibody or an antigen-binding portion thereof.INCORPORATION BY REFERENCE

[0008] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. To the extent publications and patents or patent applications incorporated by reference contradict the disclosure contained in the specification, the specification is intended to supersede and / or take precedence over any such contradictory material.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] 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 illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings (also "figure” and ‘TIG.” herein), of which:

[0010] FIG. 1 illustrates the stability of different ADCs in mouse plasma;

[0011] FIG. 2 illustrates the stability of different ADCs in human plasma;

[0012] FIG. 3 illustrates the percentage of cellular binding of different ADCs;

[0013] FIG. 4 illustrates the median fluorescence intensity (MFI) of different ADCs binding to JeKo cells;

[0014] FIG. 5 illustrates the percentage of inhibition of Jeko-1 cell grow th of different ADCs;

[0015] FIG. 6 illustrates internalization of different ADCs;

[0016] FIG. 7 illustrates the release of exatecan from the ADC;

[0017] FIG. 8 illustrates Pharmacokinetic Parameters of various ADCs;

[0018] FIG. 9 in vivo antitumor activity of ADCs in the H1975 xenograft model;

[0019] FIG. 10 in vivo antitumor activity of ADCs in the H520 xenograft model;

[0020] FIG. 11 in vivo antitumor activity of ADCs in the LCLC-103H xenograft model;

[0021] FIG. 12 shows in vivo antitumor activity of ADCs for 12 PTK7 antibodies in the H1975 NSCLC model;

[0022] FIG. 13 shows in vivo antitumor activity of ADCs for 4 PTK7 antibodies in the Hl 975 NSCLC xenograft model;

[0023] FIG. 14 shows in vivo antitumor activity for ADC-21 and ADC-22 in the H1975 NSCLC xenograft model;

[0024] FIG. 15 shows in vivo antitumor activity of ADCs in the Hep3B (liver) xenograft model;

[0025] FIG. 16 shows in vivo antitumor activity of ADCs in the Dul45 (prostate) xenograft model;

[0026] FIG. 17 shows in vivo antitumor activity of ADCs with a chimeric PTK7 antibody and a humanized PTK7 antibody in H520 NSCLC xenograft model;

[0027] FIG. 18 in vivo antitumor activity of ADCs in H520 xenograft model;

[0028] FIG. 19 in vivo antitumor activity of ADCs in the LCLC-103H xenograft model;

[0029] FIG. 20 in vivo antitumor activity of ADCs in the MDA-MB-468 xenograft model;

[0030] FIG. 21 in vivo antitumor activity of ADCs in the LCLC-103H xenograft model;

[0031] FIG. 22 in vivo antitumor activity of ADCs in the PA-1 (ovarian) xenograft model;

[0032] FIG. 23 in vivo antitumor activity of ADC-4 in the LCLC-103H xenograft model;

[0033] FIG. 24 in vivo antitumor activity of ADC-4 in the TNBC xenograft model;

[0034] FIG. 25 in vivo antitumor activity of ADC-4 in the SA4121 (sarcoma) xenograft model;

[0035] FIG. 26 in vivo antitumor activity of ADC-4 in the OV 14661 (ovarian) xenograft model; and

[0036] FIG. 27 in vivo antitumor activity of ADC-4 in the HN0635 (head and neck) xenograft model.DETAILED DESCRIPTION OF THE INVENTION

[0037] The following description sets forth numerous exemplary configurations, methods, parameters, and the like. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure, but is instead provided as a description of exemplary embodiments.

[0038] In the following descnption. certain specific details are set forth in order to provide a thorough understanding of various embodiments of the disclosure. However, one skilled in the art will understand that the disclosure may be practiced without these details.Definitions

[0039] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this invention belongs. All patents and publications referred to herein are incorporated by reference.

[0040] "Alkyl" refers to a straight or branched hydrocarbon chain radical consisting solely of carbon and hydrogen atoms, containing no unsaturation, and preferably having from one to fifteen carbon atoms (i.e., C1-C15 alkyl). In certain embodiments, an alkyl comprises one to thirteen carbon atoms (i.e., C1-C13 alkyl). In certain embodiments, an alky l comprises one to eight carbon atoms (i.e., Ci-Cs alkyl). In other embodiments, an alkyl comprises one to five carbon atoms (i.e., C1-C5 alkyl). In other embodiments, an alkyl comprises one to four carbon atoms (i.e., C1-C4 alkyd). In other embodiments, an alkyd comprises one to three carbon atoms (i.e., C1-C3 alkyl). In other embodiments, an alkyl comprises one to two carbon atoms (i.e., Ci- C2 alkyl). In other embodiments, an alkyl comprises one carbon atom (i.e., Ci alkyl). In other embodiments, an alkyl comprises five to fifteen carbon atoms (i.e., C5-C15 alkyl). In other embodiments, an alkyl comprises five to eight carbon atoms (i.e., Cs-Cs alkyl). In other embodiments, an alkyl comprises two to five carbon atoms (i.e., C2-C5 alkyl). In other embodiments, an alkyd comprises three to five carbon atoms (i.e., C3-C5 alkyl). In certain embodiments, the alkyl group is selected from methyl, ethyl, 1 -propyl (n- rop l). 1 -methylethyl (i o-propyl), 1 -butyl (w-butyl ). 1 -methyl propyl (sec-butyl), 2-methylpropyl (zso-butyl), 1,1 -dimethylethyl ( / c / 7-bul l). I -pent l (w-pentyl). The alkyl is attached to the rest of the molecule by a single bond.

[0041] The term “Cx-y” when used in conjunction with a chemical moiety, such as alkyl, alkenyl, or alkynyl is meant to include groups that contain from x to y carbons in the chain. For example, the term “Ci-ealkyl” refers to substituted or unsubstituted saturated hydrocarbon groups, including straight-chain alkyl and branched-chain alkyl groups that contain from 1 to 6 carbons. The term -Cx-yalkylene- refers to a substituted or unsubstituted alkylene chain with from x to y carbons in the alkylene chain. For example -Ci-ealkylene- may be selected from methylene, ethylene, propylene, butylene, pentylene, and hexylene, any one of which is optionally substituted.

[0042] "Alkoxy" refers to a radical bonded through an oxygen atom of the formula -O-alkyl, where alkyl is an alkyl chain as defined above.

[0043] "Alkenyl" refers to a straight or branched hydrocarbon chain radical group consisting solely 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-C12 alkenyl). In certain embodiments, an alkenyl comprises two to eight carbon atoms (i.e.. C2-C8 alkenyl). In certainembodiments, an alkenyl comprises two to six carbon atoms (i.e., C2-C6 alkenyl). In other embodiments, an alkenyl comprises two to four carbon atoms (i.e., C2-C4 alkenyl). The alkenyl is attached to the rest of the molecule by a single bond, for example, ethenyl (z.e., vinyl), prop-l-enyl (z'.e., allyl), but-l-enyl, pent-l-enyl, penta- 1,4-dienyl, and the like.

[0044] "Alkynyl" refers to a straight or branched hydrocarbon chain radical group consisting solely of carbon and hydrogen atoms, containing at least one carbon-carbon triple bond, and preferably having from two to twelve carbon atoms (z.e., C2-C12 alkynyl). In certain embodiments, an alkynyl comprises two to eight carbon atoms (z.e., C2-C8 alkynyl). In other embodiments, an alkynyl comprises two to six carbon atoms (i.e.. C2-C6 alkynyl). In other embodiments, an alkynyl comprises two to four carbon atoms (i.e., C2-C4 alkynyl). The alkynyl is attached to the rest of the molecule by a single bond, for example, ethynyl, propynyl, butynyl, pent nyl, hexynyl, and the like.

[0045] The terms ‘LCx-yalkenyl” and “Cx-yalkynyl” refer to substituted or unsubstituted unsaturated aliphatic groups analogous in length and possible substitution to the alkyls described above, but that contain at least one double or triple bond, respectively. The term -Cx.yalkenylene- refers to a substituted or unsubstituted alkenylene chain with from x to y carbons in the alkenylene chain. For example, -C2-6alkenylene- may be selected from ethenylene, propenylene. butenylene, pentenylene. and hexenylene, any one of which is optionally substituted. An alkenylene chain may have one double bond or more than one double bond in the alkenylene chain. The term -Cx-yalkynylene- refers to a substituted or unsubstituted alkynylene chain with from x to y carbons in the alkenylene chain. For example, -C2- ealkenylene- may be selected from ethynylene, propynylene, butynylene, pentynylene, and hexynylene, any one of which is optionally substituted. An alkynylene chain may have one triple bond or more than one triple bond in the alkynylene chain.

[0046] "Alkylene" or "alkylene chain" refers to a straight or branched divalent hydrocarbon chain linking the rest of the molecule to a radical group, consisting solely of carbon and hydrogen, containing no unsaturation, and preferably having from one to twelve carbon atoms, for example, methylene, ethylene, propylene, rz-butylene, and the like. The alkylene chain is attached to the rest of the molecule through a single bond and to the radical group through a single bond. The points of attachment of the alky lene chain to the rest of the molecule and to the radical group may be through any two carbons within the chain. In certain embodiments, an alkylene comprises one to ten carbon atoms (i.e.. Ci-Cs alkydene). In certain embodiments, an alkylene comprises one to eight carbon atoms (i.e., Ci-Cs alkylene). In other embodiments, an alky dene comprises one to five carbon atoms (i.e., C1-C5 alkylene). In other embodiments, an alkylene comprises one to four carbon atoms (i.e., C1-C4 alkylene). In other embodiments, analkylene comprises one to three carbon atoms (z'.e., C1-C3 alkylene). In other embodiments, an alkylene comprises one to two carbon atoms (z.e., C1-C2 alkylene). In other embodiments, an alky lene comprises one carbon atom (z.e., Ci alkylene). In other embodiments, an alkylene comprises five to eight carbon atoms (z'.e., Cs-Cs alkylene). In other embodiments, an alkylene comprises two to five carbon atoms (z.e., C2-C5 alkylene). In other embodiments, an alkylene comprises three to five carbon atoms (z.e., C3-C5 alkylene).

[0047] "Alkenylene" or "alkenylene chain" refers to a straight or branched divalent hydrocarbon chain linking the rest of the molecule to a radical group, consisting solely of carbon and hydrogen, containing at least one carbon-carbon double bond, and preferably having from two to twelve carbon atoms. The alkenylene chain is attached to the rest of the molecule through a single bond and to the radical group through a single bond. The points of attachment of the alkenylene chain to the rest of the molecule and to the radical group may be through any two carbons within the chain. In certain embodiments, an alkenylene comprises two to ten carbon atoms (i.e.. C2-C10 alkenylene). In certain embodiments, an alkenylene comprises two to eight carbon atoms (i.e., C2-C8 alkenylene). In other embodiments, an alkenylene comprises two to five carbon atoms (i.e., C2-C5 alkenylene). In other embodiments, an alkenylene comprises two to four carbon atoms (i.e., C2-C4 alkenylene). In other embodiments, an alkenylene comprises two to three carbon atoms (i.e., C2-C3 alkenylene). In other embodiments, an alkenylene comprises two carbon atom (i.e., C2 alkenylene). In other embodiments, an alkenylene comprises five to eight carbon atoms (i.e., Cs-Cs alkenylene). In other embodiments, an alkenylene comprises three to five carbon atoms (i.e., C3-C5 alkenylene).

[0048] "Alkynylene" or "alkynylene chain" refers to a straight or branched divalent hydrocarbon chain linking the rest of the molecule to a radical group, consisting solely of carbon and hydrogen, containing at least one carbon-carbon triple bond, and preferably having from two to tw elve carbon atoms. The alky nylene chain is attached to the rest of the molecule through a single bond and to the radical group through a single bond. The points of attachment of the alkynylene chain to the rest of the molecule and to the radical group may be through any two carbons within the chain. In certain embodiments, an alkynylene comprises two to ten carbon atoms (i.e., C2-C10 alkynylene). In certain embodiments, an alkynylene comprises two to eight carbon atoms (i.e., C2-C8 alkynylene). In other embodiments, an alkynylene comprises two to five carbon atoms (i.e.. C2-C5 alkynylene). In other embodiments, an alkynylene comprises two to four carbon atoms (i.e., C2-C4 alkynylene). In other embodiments, an alkynylene comprises two to three carbon atoms (i.e., C2-C3 alkynylene). In other embodiments, an alkynylene comprises two carbon atom (i.e., C2 alkynylene). In other embodiments, an alkynylenecomprises five to eight carbon atoms (z.e., Cs-Cs alkynylene). In other embodiments, an alkynylene comprises three to five carbon atoms (z.e., C3-C5 alkynylene).

[0049] " Aryl" refers to a radical derived from an aromatic monocyclic or aromatic multi cyclic hydrocarbon ring system by removing a hydrogen atom from a ring carbon atom. The aromatic monocyclic or aromatic multicyclic hydrocarbon ring system contains only hydrogen and carbon and from five to eighteen carbon atoms, where at least one of the rings in the ring system is aromatic, z.e., it contains a cyclic, delocalized (4n+2) n-electron system in accordance with the Htickel theory. The ring system from which aryl groups are derived include, but are not limited to, groups such as benzene, fluorene, indane, indene, tetralin and naphthalene.

[0050] "Aralkyl" refers to a radical of the formula -Rc-aryl where Rcis an alkylene chain as defined above, for example, methy lene, ethylene, and the like.

[0051] " Aralkenyl" refers to a radical of the formula -Rd-aryl where Rdis an alkenylene chain as defined above. " Aralkynyl" refers to a radical of the formula -Re-aryl, where Reis an alkynylene chain as defined above.

[0052] “Carbocycle’' refers to a saturated, unsaturated or aromatic rings in which each atom of the ring is carbon. Carbocycle may include 3- to 10-membered monocyclic rings, 6- to 12- membered bicyclic rings, and 6- to 12-membered bridged rings. Each ring of a bicyclic carbocycle may be selected from saturated, unsaturated, and aromatic rings. An aromatic ring, e.g., phenyl, may be fused to a saturated or unsaturated ring, e.g., cyclohexane, cyclopentane, or cyclohexene. Any combination of saturated, unsaturated and aromatic bicyclic rings, as valence permits, are included in the definition of carbocyclic. Exemplary carbocycles include cyclopentyl, cyclohexyl, cyclohexenyl, adamantyl, phenyl, indanyl, and naphthyl. Bicyclic carbocycles may be fused, bridged or spiro-ring systems. In some cases, spiro-ring carbocycles have at least two molecular rings with only one common atom.

[0053] “Carbocyclene” refers to a divalent carbocycle linking the rest of the molecule to a radical group.

[0054] The term “unsaturated carbocycle” refers to carbocycles with at least one degree of unsaturation and excluding aromatic carbocycles. Examples of unsaturated carbocycles include cyclohexadiene, cyclohexene, and cyclopentene.

[0055] "Cycloalkyl" refers to a fully saturated monocyclic or polycyclic hydrocarbon radical consisting solely of carbon and hydrogen atoms, which includes fused or bridged ring systems, and preferably having from three to twelve carbon atoms. In certain embodiments, a cycloalkyl comprises three to ten carbon atoms. In other embodiments, a cycloalkyl comprises five to seven carbon atoms. The cycloalkyl may be attached to the rest of the molecule by a single bond.Examples of monocyclic cycloalkyls include, e.g., cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Polycyclic cycloalkyl radicals include, for example, adamantyl, norbomyl (z.e., bicyclo[2.2.1]heptanyl), norbomenyl, decalinyl, 7,7-dimethyl-bicyclo[2.2.1]heptanyl, and the like.

[0056] "Cycloalkenyl" refers to an unsaturated non-aromatic monocyclic or polycyclic hydrocarbon radical consisting solely of carbon and hydrogen atoms, which includes fused or bridged ring systems, preferably having from three to twelve carbon atoms and comprising at least one double bond. In certain embodiments, a cycloalkenyl comprises three to ten carbon atoms. In other embodiments, a cycloalkenyl comprises five to seven carbon atoms. The cycloalkenyl may be attached to the rest of the molecule by a single bond. Examples of monocyclic cycloalkenyls includes, e.g., cyclopentenyl, cyclohexenyl, cycloheptenyl, and cyclooctenyl.

[0057] "Cycloalkylalkyl" refers to a radical of the formula -Rc-cycloalkyl where Rcis an alkylene chain as described above.

[0058] "Cycloalkylalkoxy" refers to a radical bonded through an oxygen atom of the formula -O-Rc-cycloalkyl where Rcis an alkylene chain as described above.

[0059] "Halo" or "halogen" refers to halogen substituents such as bromo, chloro, fluoro and iodo substituents.

[0060] As used herein, the term "haloalkyl" or “haloalkane’’ refers to an alkyl radical, as defined above, that is substituted by one or more halogen radicals, for example, trifluoromethyl, di chloromethyl, bromomethyl, 2,2,2-trifluoroethyl, 1 -fluoromethyl-2-fluoroethyl, and the like. In some embodiments, the alkyl part of the fluoroalkyl radical is optionally further substituted. Examples of halogen substituted alkanes (“haloalkanes”) include halomethane (e.g., chloromethane, bromomethane, fluoromethane, iodomethane), di-and trihalomethane (e g., tri chloromethane, tri bromomethane, trifluoromethane, triiodomethane), 1-haloethane, 2- haloethane. 1,2-dihaloethane, 1-halopropane, 2-halopropane, 3-halopropane, 1 ,2-dihalopropane, 1,3-dihalopropane. 2,3-dihalopropane. 1,2,3-trihalopropane, and any other suitable combinations of alkanes (or substituted alkanes) and halogens (e g., Cl, Br, F, I, etc ). When an alkyl group is substituted with more than one halogen radicals, each halogen may be independently selected e.g., 1 -chloro, 2-fluoroethane.

[0061] "Fluoroalkyl" refers to an alkyl radical, as defined above, that is substituted by one or more fluoro radicals, for example, trifluoromethyl, difluoromethyl, fluoromethyl, 2,2,2-trifluoroethyl, l-fluoromethyl-2-fluoroethyl, and the like.

[0062] "Hydroxyalkyl" refers to an alkyl radical, as defined above, that is substituted by one or more hydroxy radicals, for example, propan-l-ol, butane- 1,4-diol, pentane-l,2,4-triol, and the like.

[0063] "Alkoxyalkyl" refers to an alkyl radical, as defined above, that is substituted by one or more alkoxy radicals, for example, methoxymethane. 1,3-dimethoxybutane, 1- methoxypropane, 2-ethoxypentane, and the like.

[0064] “Activated C=C group” refers to a cyclic alky ne which is highly reactive due to ring strain towards azide group to form a triazole.

[0065] "Activated disulfide group” refers to a disulfide which is capable to react with a thiol to form a new disulfide bond.

[0066] "Cyanoalkyl" as used herein refers to an alkyd radical, as defined above, that is substituted by one or more cyano radicals, for example, acetonitrile, 2-ethyl-3- methylsuccinonitrile, butyronitrile, and the like.

[0067] “Heterocycle” refers to a saturated or unsaturated or aromatic ring comprising one or more heteroatoms. Exemplary heteroatoms include N, O, Si, P, B, and S atoms. Heterocycles include 3- to 10-membered monocyclic rings, 6- to 12-membered bicyclic rings, and 6- to 12- membered bridged rings. Each ring of a bicyclic heterocycle may be selected from saturated, unsaturated, and aromatic rings. Bicyclic heterocycles may be fused, bridged or spiro-ring systems. In some cases, spiro-ring heterocycles have at least two molecular rings with only one common atom. The spiro-ring heterocycle includes at least one heteroatom.

[0068] “Heterocyclene” refers to a divalent heterocycle linking the rest of the molecule to a radical group.

[0069] "Heteroaryl" or “aromatic heterocycle” refers to a radical derived from a heteroaromatic ring radical that comprises one to eleven carbon atoms and at least one heteroatom wherein each heteroatom may be selected from N, O, and S. As used herein, the heteroaryl ring may be selected from monocyclic or bicyclic and fused or bridged ring systems rings wherein at least one of the rings in the ring system is aromatic, z.e., it contains a cyclic, delocalized (4n+2) rr-electron system in accordance with the Htickel theory. The heteroatom(s) in the heteroaryl radical may be optionally oxidized. One or more nitrogen atoms, if present, are optionally quatemized. The heteroaryl may be attached to the rest of the molecule through any atom of the heteroaryl, valence permitting, such as a carbon or nitrogen atom of the heteroaryl. Examples of heteroaryls include, but are not limited to, pyridine, pyrimidine, oxazole, furan, pyran, thiophene, isoxazole, benzimidazole, benzthiazole, and imidazopyridine.

[0070] An “X-membered heteroaryl” refers to the number of endocylic atoms, i.e., X, in the ring. For example, a 5-membered heteroaryl ring or 5-membered aromatic heterocycle has 5 endocyclic atoms, e.g., triazole, oxazole, thiophene, etc.

[0071] The term “unsaturated heterocycle'’ refers to heterocycles with at least one degree of unsaturation and excluding aromatic heterocycles. Examples of unsaturated heterocycles include dihydropyrrole, dihydrofuran, oxazoline, pyrazoline, and dihydropyridine. Heterocycles may be optionally substituted by one or more substituents such as those substituents described herein.

[0072] The term “substituted” refers to moieties having substituents replacing a hydrogen on one or more carbons or substitutable heteroatoms, e.g., NH. of the structure. It will be understood that “substitution” or “substituted with” includes the implicit proviso that such substitution is in accordance with permitted valence of the substituted atom and the substituent, and that the substitution results in a stable compound, i. e. , a compound which does not spontaneously undergo transformation such as by rearrangement, cyclization, elimination, etc. In certain embodiments, substituted refers to moieties having substituents replacing two hydrogen atoms on the same carbon atom, such as substituting the two hydrogen atoms on a single carbon with an oxo, imino or thioxo group.

[0073] As used herein, the term “substituted” is contemplated to include all permissible substituents of organic compounds. In a broad aspect, the permissible substituents include acyclic and cyclic, branched and unbranched, carbocyclic and heterocyclic, aromatic and nonaromatic substituents of organic compounds. The permissible substituents can be one or more and the same or different for appropriate organic compounds. For purposes of this disclosure, the heteroatoms such as nitrogen may have hydrogen substituents and / or any permissible substituents of organic compounds described herein which satisfy the valences of the heteroatoms. In some embodiments, substituents may include any substituents described herein, for example: halogen, hydroxy, oxo (=0), thioxo (=S), cyano (-CN), nitro (-NO2), imino (=N- H), oximo (=N-0H), hydrazino (=N-NH2), -Rb-ORa, -Rb-OC(O)-Ra, -Rb-OC(O)-ORa, -Rb-OC(O)-N(Ra)2. -Rb-N(Ra)2. -Rb-C(O)Ra, - Rb-C(O)ORa, -Rb-C(O)N(Ra)2, -Rb-O-Rc-C(O)N(Ra)2, -Rb-N(Ra)C(O)ORa, -Rb-N(Ra)C(O)Ra, -Rb-N(Ra)S(O)tRa(where t is 1 or 2), -Rb-S(O)tRa(where t is 1 or 2), -Rb-S(O)tORa(where t is 1 or 2), and -Rb-S(O)tN(Ra)2 (where t is 1 or 2); and alkyl, alkenyl, alkynyl, aryl, aralkyl, aralkenyl, aralkynyl, cycloalkyl, cycloalkylalkyd, and heterocycle, any of which may be optionally substituted by alkyl, alkenyl, alkynyl, halogen, haloalkyl, haloalkenyl, haloalkynyl, oxo (=0), thioxo (=S), cyano (-CN), nitro (-NO2), imino (=N-H), oximo (=N-0H), hydrazine (=N-NH2), -Rb-ORa, -Rb-OC(O)-Ra, -Rb-OC(O)-ORa, -Rb-OC(O)-N(Ra)2, -Rb-N(Ra)2, -Rb-C(O)Ra, -Rb-C(O)ORa, -Rb-C(O)N(Ra)2. -Rb-O-Rc-C(O)N(Ra)2. -Rb-N(Ra)C(O)ORa, -Rb-N(Ra)C(O)Ra, -Rb-N(Ra)S(O)tRa(where t is 1 or 2), -Rb-S(O)tRa(where t is 1 or 2), -Rb-S(O)tORa(where t is 1 or 2) and -Rb-S(O)tN(Ra)2 (where t is 1 or 2); wherein each Rais independently selected from hydrogen, alkyl, cycloalk l, cycloalkylalkyd, aryl, aralkyl, heterocycloalky l, heterocycloalky lalkyl, heteroaryl, or heteroarylalkyl, wherein each Ra, valence permitting, may be optionally substituted with alkyl, alkenyl, alkynyl, halogen, haloalkyL haloalkenyl, haloalkynyl, oxo (=0), thioxo (=S), cyano (-CN), nitro (-NO2), imino (=N-H), oximo (=N-0H), hydrazine (=N-NH2), -Rb-0Ra, -Rb-0C(0)-Ra, -Rb-0C(0)-0Ra, -Rb-0C(0)-N(Ra)2, -Rb-N(Ra)2, -Rb-C(O)Ra, -Rb-C(O)ORa, -Rb-C(0)N(Ra)2. -Rb-0-Rc-C(0)N(Ra)2. -Rb-N(Ra)C(0)0Ra, -Rb-N(Ra)C(0)Ra, -Rb- N(Ra)S(O)tRa(where t is 1 or 2), -Rb-S(O)tRa(where t is 1 or 2), -Rb-S(O)tORa(where t is 1 or 2) and -Rb-S(O)tN(Ra)2(where t is 1 or 2); and wherein each Rbis independently selected from a direct bond or a straight or branched alky lene, alkenylene, or alkynylene chain, and each Rcis a straight or branched alkylene, alkenylene or alky nylene chain.

[0074] As used in the specification and claims, the singular form "a". "an " and "‘the” includes plural references unless the context clearly dictates otherwise.

[0075] The term “salt” or “pharmaceutically acceptable salt” refers to salts derived from a variety of organic and inorganic counter ions 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, -toluenesul Ionic acid, salicylic acid, and the like. Pharmaceutically acceptable base addition salts can be formed with inorganic 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', secondary7, 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 salt is chosen from ammonium, potassium, sodium, calcium, and magnesium salts.

[0076] The phrases “parenteral administration” and “administered parenterally” as used herein means modes of administration other than enteral and topical administration, usually by injection, and includes, without limitation, intravenous, intramuscular, intraarterial, intrathecal,intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal, transtracheal, subcutaneous, subcuticular, intraarticular, subcapsular, subarachnoid, intraspinal and intrastemal injection and infusion.

[0077] The phrase “pharmaceutically acceptable” is employed herein to refer to those compounds, materials, compositions, and / or dosage forms which are. within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit / risk ratio.

[0078] The phrase “pharmaceutically acceptable excipient” or “pharmaceutically acceptable carrier” as used herein means 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 which can serve as pharmaceutically acceptable carriers include: (1) sugars, such as lactose, glucose and sucrose;(2) starches, such as com 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, com 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) ethyl alcohol; (20) phosphate buffer solutions; and (21) other non-toxic compatible substances employed in pharmaceutical formulations.

[0079] In certain embodiments, the term “prevent” or “preventing” as related to a disease or disorder may refer to a compound that, in a statistical sample, reduces the occurrence of the disorder or condition in the treated sample relative to an untreated control sample, or delays the onset or reduces the severity of one or more symptoms of the disorder or condition relative to the untreated control sample.

[0080] The terms “treat,” “treating” or “treatment,” as used herein, may include alleviating, abating or ameliorating a disease or condition symptoms, preventing additional symptoms, ameliorating or preventing the underlying causes of symptoms, inhibiting the disease or condition, e.g., arresting the development of the disease or condition, relieving the disease or condition, causing regression of the disease or condition, relieving a condition caused by thedisease or condition, or stopping the symptoms of the disease or condition either prophylactically and / or therapeutically.

[0081] The term "ligand" generally refers to a macromolecular compound capable of recognizing and binding to an antigen or receptor associated with a target cell. The ligand can be used to bring the drug to the target cell population that binds to the ligand, including but not limited to protein hormones, lectins, growth factors, antibodies, or others that can bind to cells, receptors and / or antigens molecule. The ligand can be an antibody. The ligand can be an antigen binding fragment.

[0082] The term “targeting moiety" or “Targeting Unit’7refers to a structure that has a selective affinity for a target molecule relative to other non-target molecules. The targeting moiety binds to a target molecule. A Targeting Unit may include, for example, an antibody, a peptide, a ligand, a receptor, or a binding portion thereof. The target biological molecule may be a biological receptor or other structure of a cell such as a tumor antigen.

[0083] The term “antibody” means whole antibodies and any antigen binding fragment (i.e., “antigen-binding portion”) or single chain variants thereof. A whole antibody is a protein comprising at least two heavy (H) chains and two light (L) chains inter-connected by disulfide bonds. Each heavy chain comprises a heavy chain variable region (VH) and a heavy chain constant region comprising three domains, CHI, CH2 and CH3. Each light chain comprises a light chain variable region (VL or Vk) and a light chain constant region comprising one single domain, CL. The VH and VL regions can be further subdivided into regions of hypervariability, termed complementarity determining regions (CDRs), interspersed with more conserved framework regions (FRs). Each VH and VL comprises three CDRs and four FRs, arranged from amino- to carboxy -terminus in the following order: FR1, CDR1, FR2, CDR2, FR3. CDR3. and FR4. The variable regions contain a binding domain that interacts with an antigen. The constant regions may mediate the binding of the antibody to host tissues or factors, including various cells of the immune system (e.g., effector cells) and the first component (Clq) of the classical complement system. The assignment of amino acid numbers, and of FR and CDR regions, in the heavy or light chain may be in accordance with IMGT" definitions (Lefranc et al., Dev Comp Immunol. (2003) 27(l):55-77); or the definitions of Kabat, Sequences of Proteins of Immunological Interest (National Institutes of Health, Bethesda, MD (1987 and 1991)); Chothia & Lesk, J Mol Biol. (1987) 196:901-17; Chothia et al., Nature (1989) 342:878-83; Abhinandan et al.. Molecular Immunology (2008) 45(14):3832-39; MacCallum et al., J Mol Biol. (1996) 262:732-45; or Honegger and Pliickthun, J Mol Biol. (2001) 309(3):657-70. The CDR boundaries of various schemes are illustrated below, where the amino acid numbers are Kabat numbers unless otherwise indicated.CDR Delineations According to Various Schemes

[0084] An antibody is said to ‘"specifically bind” to an antigen X if the antibody binds to antigen X with a KD of 5 x 10sM or less, more preferably 1 x 10sM or less, more preferably 6 / 109M or less, more preferably 3* 109M or less, even more preferably 2 / 109M or less. The antibody can be chimeric, humanized, or, preferably, human. The heavy chain constant region can be engineered to affect glycosylation type or extent, to extend antibody half-life, to enhance or reduce inter-actions with effector cells or the complement system, or to modulate some other property. The engineering can be accomplished by replacement, addition, or deletion of one or more amino acids or by replacement of a domain with a domain from another immunoglobulin type, or a combination of the foregoing.

[0085] The term "antigen binding fragment’7and "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 show n that the antigen-binding function of an antibody can be performed by fragments of a full-length antibody, such as (i) a Fab fragment, a monovalent fragment consisting of the VL, VH. CL and CHI domains; (ii) a F(ab’)2 fragment, a bivalent fragment comprising two Fab fragments linked by a disulfide bridge at the hinge region; (iii) a Fab’ fragment, which is essentially an Fab with part of the hinge region (see, for example, Abbas et al., Cellular and Molecular Immunology, 6th Ed., Saunders Elsevier 2007); (iv) a Fd fragment consisting of the VH and CHI domains; (v) a Fv fragment consisting of the VL and VH domains of a single arm of an antibody, (vi) a dAb fragment (Ward et al., (1989) Nature 341:544-546), which consists of a VH domain; (vii) an isolated complementarity determining region (CDR); and (viii) a 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. Furthermore, although the two domains of the Fv fragment, VL and VH, are encoded by separate genes, they can be joined, using recombinant methods, by a synthetic linker that enables them to be made as a single protein chain in which the VL and VH regions pair to form monovalent molecules (known assingle chain Fv, or scFv); see, e.g., 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.

[0086] The term “isolated antibody’" means an antibody that is substantially free of other antibodies having different antigenic specificities (e.g., an isolated antibody that specifically binds antigen X is substantially free of antibodies that specifically bind antigens other than antigen X). An isolated antibody that specifically binds antigen X may, however, have crossreactivity to other antigens, such as antigen X molecules from other species. In certain embodiments, an isolated antibody specifically binds to human antigen X and does not crossreact with other (non-human) antigen X antigens. Moreover, an isolated antibody may be substantially free of other cellular material and / or chemicals.

[0087] The term “monoclonal antibody” or “monoclonal antibody composition” means a preparation of antibody molecules of single molecular composition, which displays a single binding specificity and affinity for a particular epitope.

[0088] The term “human antibody” means an antibody having variable regions in which both the framework and CDR regions (and the constant region, if present) are derived from human germline immunoglobulin sequences. Human antibodies may include later modifications, including natural or synthetic modifications. Human antibodies may include amino acid residues not encoded by human germline immunoglobulin sequences (e.g., mutations introduced by random or site-specific mutagenesis in vitro or by somatic mutation in vivo). However, “human antibody"’ does not include antibodies in which CDR sequences derived from the germline of another mammalian species, such as a mouse, have been grafted onto human framework sequences.

[0089] The term “human monoclonal antibody” means an antibody displaying a single binding specificity7, w hich has variable regions in which both the framework and CDR regions are derived from human germline immunoglobulin sequences. In one embodiment, human monoclonal antibodies are produced by a hybridoma that includes a B cell obtained from a transgenic nonhuman animal, e g., a transgenic mouse, having a genome comprising a human heavy chain transgene and a light chain transgene fused to an immortalized cell.

[0090] The term "epitope" refers to the amino acids conventionally bound by an immunoglobulin VH / VL pair, such as the antibodies, antigen binding portions thereof and other binding agents described herein. Other binding agents comprise non-antibody scaffolds. An epitope can be formed on a polypeptide from contiguous amino acids or noncontiguous amino acids juxtaposed by tertiary7folding of a protein. Epitopes formed from contiguous amino acids are typically retained on exposure to denaturing solvents, whereas epitopes formed by tertiaryfolding are typically lost on treatment with denaturing solvents. An epitope typically includes at least 3, and more usually, at least 5, about 9, or about 8-10 amino acids in a unique spatial conformation. An epitope defines the minimum binding site for an antibody, antigen binding portions thereof and other binding agent, and thus represents the target of specificity of an antibody, antigen binding portion thereof or other immunoglobulin-based binding agent. In the case of a single domain antibody, an epitope represents the unit of structure bound by a variable domain in isolation.

[0091] A “variant’' antibody or antigen-binding portion has amino acid substitutions (which may be conservative or non-conservative) from a reference antibody or antigen-binding portion, but does not have substantially altered biologic activity from the reference antibody or antigenbinding portion. For example, the variant antibody or antigen-binding portion may retain at least 50%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% of the binding affinity of the reference antibody or antigen-binding portion, or may exceed the binding affinity of the reference antibody or antigen-binding portion.

[0092] The term “specifically binds” refers to the ability of a molecule (e.g., an antibody or antigen binding portion thereof or non-antibody scaffold) described herein to bind to a target with a KD of 10’5M (10000 nM) or less, e.g., IO’6M, IO’7M, 10’8M, IO’9M, IO’10M, 10’11M, 1012M, or less. Specific binding can be influenced by, for example, the affinity and avidity of the antibody, antigen binding portion or other binding agent and the concentration of target polypeptide.

[0093] As used herein, the term “approximately” or “about” as applied to one or more values of interest refers to a value that is similar to a stated reference value. In certain embodiments, the term refers to a range of values that fall within 10%. 9%, 8%. 7%, 6%, 5%. 4%, 3%, 2%.1%, or less in either direction (greater than or less than) of the stated reference value unless otherwise stated or otherwise evident from the context.

[0094] The term “cleavable unit” refers to a chemical group that may be cleaved by action of an internal or external, preferably external, stimulus. The stimulus triggering the cleavage of the cleavable unit may be for instance pH or temperature conditions, or the presence of an enzyme.

[0095] The term “cleavable sugar unit” or “sugar cleavable unit” can refer to a sugar moiety, preferably a glucuronide or a galactoside.

[0096] The term “peptide cleavable unit” can refer to a polypeptide, preferably a dipeptide or a tripeptide.Linkers, Drug-Linkers and Conjugates of the Disclosure

[0097] In an aspect, the present disclosure provides a Drug-Linker of Formula (B):Formula (B) or a pharmaceutically acceptable salt thereof, wherein;R40is selected fromC1-C30 alkylene, wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, -N(R20)C(O)-, - C(O)N(R20) , N(R20)S(O)2, S(O)2N(R20) , O , C(O) , OC(O) , C(O)O , S , S(O , -S(O)2-, 5- to 6-membered heterocyclene, or -P(O)(R20)2-;D is a Drug unit;Y1is absent or selected from -O-T1and -NH-T2;T1is a sugar cleavable unit;T2is a peptide cleavable unit;51is selected from: (i) an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(O)2- - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, - C(O)O-, -S-, -S(O)-, -S(O)2-, 5- to 6-membered heterocyclene, or -P(O)(R20)2-; (ii) optionally substituted C3-C30 alkenylene, wherein one or more alkenylene units of the C3-C30 alkenylene are optionally and independently replaced by -N(R20)- -N(R20)C(O)-. - C(O)N(R20)-, -N(R20)S(O)2-, - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, -C(O)O-, -S-, -S(O)-, — S(O)2— , or -P(O)(R20)2; (iii) one or more amino acid(s); (iv) one or more N-substituted amino acid(s); (v) optionally substituted poly ether; (vi) optionally substituted C3-C10 carbocyclene; (vii) optionally substituted 5- to 10-membered heterocyclene;52is selected from an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(O)2-, - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, - C(O)O-, -S-, — S(O)~ , — S(O)2— , 5- to 6-membered heterocyclene. or -P(O)(R20)2-;53is selected from a spacer, wherein S3is present or absent: wherein the optional substituents on M1, K1, S1, S2, and S3, are independently selected at each occurrence from:(i) halogen, -OR30, -N(R30)2, -SR30, -N(R30)2, -C(O)R30, -C(O)N(R30)2, -N(R30)C(O)R30, -C(O)OR30, -OC(O)R30. -S(O)R30, -S(O)2R30. -O-S(O)2OR30, -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =S, =N(R30), and -CN;(ii) Ci-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, -N(R30)2, -C(O)R30, - C(O)N(R30)2, -N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O-S(O)2OR30. -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =S, =N(R30), -CN, C3-10 carbocycle and 3- to 10-membered heterocycle; and(iii) C3-10 carbocycle and 3- to 10-membered heterocycle each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, - N(R30)2, -C(O)R30, -C(O)N(R30)2, -N(R30)C(O)R30-C(O)OR30, -OC(O)R30, -S(O)R30, - S(O)2R30, -P(O)(OR30)2, -OP(0)(OR30)2. -NO2, =0, =S, =N(R30), -CN, Ci-6alkyl. C2-6 alkenyl, and C2-6 alkynyl;M1is a group which can react with a ligand to form a connector unit;K1is selected from:(i) a peptide unit,(ii) an oligosaccharide; and(iii) a poly ether; each R20is independently selected from hydrogen; and Ci-6 alky l, C2-6 alkenyl, C2-6 alkynyl, C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen. -OH. -CN. -NO2, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl, -O-Ci-10 alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle; and each R30is independently selected from hydrogen; and C1-6 alkyl, C2-6 alkenyl, C2-6 alky nyl, C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen. -OH. -CN. -NO2, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl, -O-Ci-10 alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle.

[0098] In some embodiments, the Drug-Linker of Formula (B) is represented by Formula (X). In some cases, the Drug-Linker of Formula (B) is represented by Formula (X). In some cases, the Drug-Linker further comprises a Targeting unit, wherein M1reacts with the Targeting unit and forms M2.

[0099] In an aspect, the present disclosure provides a Drug-Linker of Formula (X):Formula (X)or a pharmaceutically acceptable salt thereof, wherein;D is a Drug unit;Y1is absent or selected from -O-T1and -NH-T2;T1is a sugar cleavable unit;T2is a peptide cleavable unit;51is selected from: (i) an optionally substituted C1-C30 alkylene wherein one or more alkydene units of the C1-C30 alky lene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(O)2- - S(O)2N(R20)- -O-, -C(O)-, -OC(O)-, - C(O)O-, -S-, — S(O)~ , -S(O)2- 5- to 6-membered heterocyclene. or -P(O)(R20)2-; (ii) optionally substituted C3-C30 alkenylene, wherein one or more alkenylene units of the C3-C30 alkenylene are optionally and independently replaced by -N(R20)-, -N(R20)C(O)-, - C(O)N(R20)-, -N(R20)S(O)2-, - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, -C(O)O-, -S-, -S(O)-, -S(O)2-, or -P(O)(R20)2; (iii) one or more amino acid(s); (iv) one or more N-substituted amino acid(s); (v) optionally substituted polyether; (vi) optionally substituted C3-C10 carbocyclene; (vii) optionally substituted 5- to 10-membered heterocyclene;52is selected from an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alky dene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(O)2- - S(O)2N(R20)-, -O-, -C(O)-. -OC(O)-, - C(O)O-, -S-, — S(O)~ , — S(O)2— , 5- to 6-membered heterocyclene, or -P(O)(R20)2-;53is selected from a spacer, wherein S3is present or absent; wherein the optional substituents on M1, K1, S1, S2, and S3, are independently selected at each occurrence from:(1) halogen. -OR30. -N(R30)2. -SR30, -N(R30)2, -C(O)R30. -C(O)N(R30)2, - N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O- S(O)2OR30, -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, -O. =S, =N(R30), and -CN;(ii) Ci-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30. -SR30, -N(R30)2, -C(O)R30. - C(O)N(R30)2, -N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O- S(O)2OR30, -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =S, =N(R30), -CN, C3-10 carbocycle and 3- to 10-membered heterocycle; and(iii) C3-10 carbocycle and 3- to 10-membered heterocycle each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, - N(R30)2, -C(O)R30, -C(O)N(R30)2, -N(R30)C(O)R30-C(O)OR30, -OC(O)R30, -S(O)R30, - S(O)2R30, -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, -O. =S, =N(R30), -CN, Ci-6alkyl, C2-6 alkenyl, and C2-6 alkynyl;M1is a group which can react with a ligand to form a connector unit;K1is selected from:(i) a peptide unit,(ii) an oligosaccharide; and(iii) a polyether; each R20is independently selected from hydrogen; and Ci-6 alkyd, C2-6 alkenyl, C2-6 alkynyl, C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen. -OH, -CN, -NO2, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl. -O-Ci-10 alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle; and each R30is independently selected from hydrogen; and C1-6 alkyd, C2-6 alkenyl, C2-6 alkynyl. C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen. -OH. -CN, -NO2, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl. -O-Ci-10 alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle.

[0100] In some embodiments, Formula (X) is represented byFormula (I) or a pharmaceutically acceptable salt thereof.

[0101] In an aspect, the present disclosure provides a conjugate of the Formula (C):Formula (C) or a pharmaceutically acceptable salt thereof, wherein;R40is selected fromC1-C30 alkylene, wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, -N(R20)C(O)-, - C(O)N(R20)-, -N(R20)S(O)2-, - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, -C(O)O-, -S-, -S(O)-,-S(O)2-, 5- to 6-membered heterocyclene. or -P(O)(R20)2-;L is a Targeting Unit;D is a Drug unit;Y1is absent or selected from -O-T1and -NH-T2;T1is a sugar cleavable unit;T2is peptide cleavable unit;51is selected from: (i) an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)- -C(O)N(R20)-, -N(R20)S(0)2- - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)- - C(O)O-, -S-, -S(O)-, -S(O)2- 5- to 6-membered heterocyclene, or -P(O)(R20)2-; (ii) optionally substituted C3-C30 alkenylene, wherein one or more alkenylene units of the C3-C30 alkenylene are optionally and independently replaced by -N(R20)-, -N(R20)C(O)-. - C(O)N(R20)-, -N(R20)S(0)2- - S(O)2N(R20)- -0- -C(0)-, -0C(0)-, -C(0)0- -S-, -S(0)-, -S(0)2- or -P(O)(R20)2; (iii) one or more amino acid(s); (iv) one or more N-substituted amino acid(s); (v) optionally substituted poly ether; (vi) optionally substituted C3-C10 carbocyclene; (vii) optionally substituted 5- to 10-membered heterocyclene;52is selected from an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(0)2- - S(O)2N(R20)- -0-, -C(0)-, -0C(0)-, - C(0)0-, - S- , — S(0)~ , -S(0)2-, 5- to 6-membered heterocyclene. or -P(O)(R20)2-;53is selected from a spacer, wherein S3is present or absent; wherein the optional substituents on M1, K1, S1, S2, and S3, are independently selected at each occurrence from:(i) halogen, -OR30, -N(R30)2, -SR30, -N(R30)2, -C(O)R30, -C(O)N(R30)2, - N(R30)C(O)R30, -C(O)OR30, -OC(O)R30. -S(O)R30, -S(O)2R30. -O- S(O)2OR30. -P(O)(OR30)2, -OP(O)(OR30)2. -N02, =0. =S. =N(R30). and -CN;(ii) Ci-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, -N(R30)2, -C(O)R30, - C(O)N(R30)2, -N(R30)C(0)R30,-C(0)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O- S(O)2OR30. -P(O)(OR30)2, -OP(O)(OR30)2, -N02, =0. =S. =N(R30). -CN, C3-10 carbocycle and 3- to 10-membered heterocycle; and(iii) C3-10 carbocycle and 3- to 10-membered heterocycle each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, - N(R30)2, -C(O)R30. -C(0)N(R30)2, -N(R30)C(0)R30-C(O)OR30, -OC(O)R30. -S(O)R30, - S(O)2R30, -P(O)(OR30)2, -OP(O)(OR30)2, -N02, =0, =S, =N(R30), -CN, Ci-6alkyl, C2.6alkenyl, and C2-6 alkynyl;M2is a connector unit;K1is selected from:(i) a peptide unit,(ii) an oligosaccharide; and(iii) a polyether; each R20is independently selected from hydrogen; and C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl, -O-Ci-10 alky l, oxo, Cs-i2carbocycle, and 3- to 12- membered heterocycle; and each R30is independently selected from hydrogen; and C1-6 alkyl, C2-6 alkenyl, C2-6 alky nyl, C3-i2carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, -NO2, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl, -O-Ci-10 alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocvcle.

[0102] In some embodiments, the conjugate of Formula (C) is represented by Formula (XX).In some cases, Formula (C) is represented by Formula (A).

[0103] In an aspect, the present disclosure provides a conjugate of the Formula (XX):Formula (XX) or a pharmaceutically acceptable salt thereof, wherein;L is a Targeting Unit, wherein the Targeting Unit is an anti-PTK7 antibody or an antigen-binding portion thereof;D is a Drug unit;Y1is absent or selected from -O-T1and -NH-T2;T1is a sugar cleavable unit;T2is peptide cleavable unit;S1is selected from: (i) an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(O)2-, - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, - C(O)O-, -S-, — S(O)~ , — S(O)2— , 5- to 6-membered heterocyclene, or -P(O)(R20)2-; (ii) optionally substituted C3-C30 alkenylene, wherein one or more alkenylene units of the C3- C30 alkenylene are optionally and independently replaced by -N(R20)- -N(R20)C(O)-. - C(O)N(R20)-, -N(R20)S(O)2-, - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, -C(O)O-, -S-, -S(O)-, -S(O)2-, or -P(O)(R20)2; (iii) one or more amino acid(s); (iv) one or more N-substituted aminoacid(s); (v) optionally substituted poly ether; (vi) optionally substituted C3-C10 carbocyclene; (vii) optionally substituted 5- to 10-membered heterocyclene;52is selected from an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(O)2-. - S(O)2N(R20)- -O-, -C(O)-. -OC(O)-, - C(O)O-, -S-, — S(O)~ , -S(O)2- 5- to 6-membered heterocyclene, or -P(O)(R20)2-;53is selected from a spacer, wherein S3is present or absent; wherein the optional substituents on M1, K1, S1, S2, and S3, are independently selected at each occurrence from:(1) halogen, -OR30, -N(R30)2, -SR30, -N(R30)2, -C(O)R30, -C(O)N(R30)2, - N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O- S(O)2OR30, -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =S, =N(R30), and -CN;(ii) Ci-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30. -SR30, -N(R30)2, -C(O)R30. - C(O)N(R30)2, -N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O-S(O)2OR30, -P(O)(OR30)2, -OP(O)(OR30)2, -N02, =0, =S, =N(R30), -CN, C3-10 carbocycle and 3- to 10-membered heterocycle; and(hi) C3-10 carbocycle and 3- to 10-membered heterocycle each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, - N(R30)2, -C(O)R30, -C(O)N(R30)2, -N(R30)C(O)R30-C(O)OR30, -OC(O)R30, -S(O)R30, - S(O)2R30, -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =S, =N(R30), -CN, Ci-6alkyl, C2-6 alkenyl, and C2-6 alkynyl;M2is a connector unit;K1is selected from:(i) a peptide unit,(ii) an oligosaccharide; and(hi) a polyether; each R20is independently selected from hydrogen; and C1-6 alkyl, C2-6 alkenyl, C2.6 alkynyl. C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen. -OH, -CN, -NO2, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl. -O-Ci-10 alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle; and each R30is independently selected from hydrogen; and C1-6 alky l, C2-6 alkenyl, C2-6 alkynyl, C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen. -OH. -CN, -NO2, -NH2, -N(CI-6 alky 1)2, Ci-io alkyl, -Ci-io haloalkyL -O-Ci-io alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle.

[0104] In some embodiments, Formula (XX) is represented byFormula (A) or a pharmaceutically acceptable salt thereof.

[0105] In some embodiments, for a conjugate or salt of Formula (XX) or Formula (A), L is an anti-PTK7 antibody or an antigen-binding portion thereof. In some cases, the anti-PTK7 is selected from Table 7. In some cases, the anti-PTK7 is optionally without a C-terminal lysine. In some cases, the anti-PTK7 is without a C-terminal lysine. In some cases, the anti-PTK7 is with a C-terminal lysine.

[0106] In some embodiments, for a Drug-Linker or salt of Formula (B), Formula (X) or Formula (I),S3is absent;Y1is absent or selected from a cleavable sugar and cleavable peptide (e.g., dipeptide);K1is selected from a peptide unit and oligosaccharide; and

[0107] In some embodiments, for a Drug-Linker or salt of Formula (B), Formula (X) orFormula (I),

[0108] In some embodiments, for a Linker of Formula (XXX) or Formula (II), Drug-Linker or salt of Formula (X). Formula (1), or Formula (1-A). or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l ), K1is a hydrophilic spacer. In some cases, K1isselected from polyethylene glycol units, cyclodextrin units, polyamides, hydrophilic peptides, polysaccharides and dendrimers. In some cases, K1is selected from polyamides, hydrophilic peptides, and polysaccharides. In some cases, KMS selected from hydrophilic peptides and polysaccharides. In some cases, K1is selected from hydrophilic peptides. In some cases, K1is selected from polysaccharides.

[0109] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l ), K1is a peptoid.

[0110] In some embodiments, for a Linker of Formula (XXX) or Formula (II), Drug-Linker or salt of Formula (B), Formula (X). Formula (I), or Formula (I-A). or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), S1is selected from: (i) an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, -N(R20)C(O)-, -C(O)N(R20)-, - N(R20)S(O)2-, - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, -C(O)O-, -S-, -S(O)-, -S(O)2-, or - P(O)(R20)2. In some cases. S1is selected from: (i) an optionally substituted Cg-Cio alkylene wherein one or more alkylene units of the Cs-Cio alkylene are optionally and independently replaced by -N(R20)-, -N(R20)C(O)-, -C(O)N(R20)-, or -C(O)-. In some cases, S1is an optionally substituted Ci alkylene. In some cases, S1is an optionally substituted C2alkylene. In some cases, S1is an optionally substituted C3 alkylene. In some cases, S1is an optionally substituted C4 alkylene. In some cases, S1is an optionally substituted C5 alkylene. In some cases, S1is an optionally substituted Cd, alkylene. In some cases, S1is an optionally substituted C7 alkylene. In some cases, S1is an optionally substituted Cs alkylene. In some cases, S1is an optionally substituted C9 alkylene. In some cases, S1is an optionally substituted C10 alkylene. In some cases, S1is an optionally substituted Cn alkylene. In some cases. S1is an optionally substituted C12 alkylene. In some cases, S1is an optionally substituted C13 alkylene. In some cases, S1is an optionally substituted C14 alkylene. In some cases, S1is an optionally substituted C15 alkylene. In some cases, S1is an optionally substituted Ci6 alkylene. In some cases, S1is an optionally substituted C17 alkylene. In some cases, S1is an optionally substituted Cis alkylene. In some cases, S1is an optionally substituted C19 alkylene. In some cases, S1is an optionally substituted C2o alkylene. In some cases, the one or more alkyd ene units of the alkyd ene of S1are optionally and independently replaced by -N(R20)-, -N(R20)C(O)-, -C(O)N(R20)-, - N(R20)S(O)2-, - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, -C(O)O-, -S-, -S(O)-, -S(O)2-, or - P(O)(R20)2. In some cases, the one or more alkylene units of the alkylene of S1are optionally and independently replaced by7-N(R20)-, -N(R20)C(O)-, -C(O)N(R20)-, or -C(O)-. In some cases, the one or more alky lene units of the alkylene of S1are optionally and independently replaced by -N(R20)-. In some cases, the one or more alkylene units of the alkylene of S1areoptionally and independently replaced by -N(R20)C(O)-. In some cases, the one or more alkylene units of the alkylene of S1are optionally and independently replaced by -C(O)N(R20)-. In some cases, the one or more alky lene units of the alkylene of S1are optionally and independently replaced by -C(O)-. In some cases, the one or more alkylene units of the alkylene of S1are optionally and independently replaced by -O-. In some cases, if an alkylene unit of the alkylene is replaced, the alkylene may be referred to as a resulting alkylene. In some cases, if two or more of the alkylene units of S1are replaced, the replaced alkylene units are not adjacent alky lene units. In some cases, if two or more of the alkylene units of S1are replaced, the adjacent alkylene units of the resulting alkylene are not replaced. In some cases, if two or more of the alkylene units of S1are replaced, the resulting alkylene has no repeating heteroatoms of adjacent alky lene units. In some cases, if two or more of the alkylene units of S1are replaced, the resulting alkylene has no repeating of the same heteroatoms of adjacent alky lene units. In some cases, if two or more of the alkylene units of S1are replaced, the resulting alkylene unit has no -N-N- or -O-O-. In some cases, if two or more of the alkylene units of S1are replaced, the resulting alkylene unit is a stable alkylene. In some cases, if two or more of the alkylene units of S1are replaced, the resulting alkylene unit is an unreactive alky lene. In some cases, the resulting alky lene has only 1 heteroatom. In some cases, the resulting alkylene has only 2 heteroatoms, wherein the 2 heteroatoms are different from each other. In some cases, the resulting alkylene has only 2 heteroatoms, wherein the 2 heteroatoms are not adjacent to each other. In some cases, the resulting alky lene has only 3 heteroatoms, wherein the 3 heteroatoms are not adjacent to each other. In some cases, the alkylene has 0 replaced units. In some cases, the alkylene has 1 replaced unit. In some cases, the alkylene has 2 replaced units. In some cases, the alkylene has 3 replaced units. In some cases, the alkylene has 4 replaced units. In some cases, the alkylene has 5 replaced units. In some cases, the alkydene has 6 replaced units. In some cases, no adjacent alkydene units of the alkylene are replaced. In some cases, no adjacent alky lene units resulting in two or more adjacent heteroatoms are present in the resulting alky lene (e.g., adjacent - N(R20)S(O)2- and -N(R20)- are not allowed, but the singular -N(R20)S(O)2- is allowed). In some cases, two heteroatoms can be present in a resulting alkylene if they come from a singular replaced alkylene unit. In some cases, two heteroatoms can be present in a resulting alkydene if they come from a singular replaced alkylene unit. In some cases, a resulting alkylene has two heteroatoms, the two heteroatoms are from a singular replaced alkylene unit. In some cases, there are two heteroatoms in a resulting alkylene if they result from a singular replacement of an alkylene unit.[OHl] In some embodiments, for a Linker of Formula (XXX) or Formula (II), Drug-Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt ofFormula (C), Formula (XX), Formula (A), or Formula (A-l), S1is selected from: -N(R20)C(O)- C1-C3 alkylene-N(R20)C(O)-Ci-C3 alkylene-N(R20)C(O)-Ci-C3 alkylene. In some cases, S1is selected from: -NHC(O)-Ci-C3 alkylene-NHC(O)-Ci-C3 alkylene-NHC(O)-Ci-C3 alky lene.

[0112] In some embodiments, for a Linker of Formula (XXX) or Formula (II), Drug-Linker or salt of Formula (B). Formula (X). Formula (I), or Formula (I-A). or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the optional substituents on S1, are independently selected at each occurrence from: (i) halogen, -OR30, -N(R30)2, -SR30, -N(R30)2, - C(O)R30, -C(O)N(R30)2, -N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O- S(O)2OR30. -P(O)(OR30)2, -OP(0)(OR30)2. -NO2, =0, =S, =N(R30), and -CN; (ii) Ci-io alkyl, C2- 10 alkenyl, C2-10 alkynyl, each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, -N(R30)2, -C(O)R30, -C(O)N(R30)2, - N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O-S(O)2OR30. -P(O)(OR30)2, -OP(O)(OR30)2, -N02, =0, =S, =N(R30), -CN, C3-10 carbocycle and 3- to 10-membered heterocycle. In some cases, the optional substituents on S1, are independently selected at each occurrence from: (i) halogen, -OR30, -N(R30)2, -SR30, -N(R30)2, -C(O)R30, - C(O)N(R30)2, -N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O-S(O)2OR30. -P(O)(OR30)2, -OP(O)(OR30)2. -NO2, =0, =S, =N(R30), and -CN. In some cases, the optional substituents on S1, are independently selected at each occurrence from: halogen. -OR30, -N(R30)2, =0, and -CN. In some cases, the optional substituents on S1, are independently selected at each occurrence from: =0. In some cases, the S1is unsubstituted.

[0113] In some embodiments for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the optionally substituted C1-C30 alkylene of S1is linear. In some cases, the optionally substituted C1-C30 alkylene of S1is a branched alkylene.

[0114] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), S1is selected from an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(H)C(0)-.

[0115] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), S1is selected from -NH- C(O)-Ci.C6aJkylene-NH-C(O)-Ci.C6alkylene-NH-C(O)-Ci-C6alkylene-.

[0116] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I- A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), S1is selected from -NH- C(O)-Ci-Ce alkylene-NH-C(O)-Ci-C6 alkylene-NH-C(O)-Ci-C6 alkylene-, wherein -S2-K' is bound to one of the alkylene. In some cases. S1is selected fromwherein -S2-K1is bound to one of the alkylene. In some cases, S1is selected from. wherein -S2-K1is bound to one of the alky lene, and wherein S2is -C(O)-.

[0117] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X). Formula (I), or Formula (I- A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), -S1-S2-K1is selected from

[0118] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX),Formula (A), or Formula (A-l), Y1is selected fromandselected from a peptide unit. In some cases, the peptide unit is represented bym is selected from 1 to 3; n is selected from 1 to 30;each R5is independently selected from: hydrogen and Ci-6 alkyl; each R10is independently selected from: hydrogen, methyl, isopropyl, isobutyl, secbutyl, benzy l, p-hydroxy benzyl, -CH2OH, -CH(OH)CH3, -CH2CH2SCH3, -CH2CONH2, - CH2COOH, -CH2CH2CONH2, -CH2CH2COOH. -CH2CH2CH2COOH, -(CH2)3NHC(=NH)NH2, -(CH2)3NH2, -(CH2)3NHCOCH3. -(CH2)3NHCHO. -(CH2)4NHC(=NH)NH2, -(CH2)4NH2, -(CH2)4NHCOCH3, -(CH2)4NHCHO, - (CH2)3NHCONH2, -(CH2)4NHCONH2, -CH2CH2CH(OH)CH2NH2, 2-pyridylmethyl-, 3- pyridylmethyl-, 4-pyridylmethyl-, phenyl, cyclohexyl, andandT is selected from -In some cases, each R10is selected from: hydrogen, and methyl. In some cases, the peptide unit is represented byIn some cases, each n is selected from 7 to 12. In some cases, each n is selected from 8 to 10. In some cases, each n is 8. In some cases, each n is 9. In some cases, n is 10. In some cases, each R10is hydrogen. In some cases, each R5is independently selected from: hydrogen and methyl. In

[0119] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I- A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), S2is selected from an optionally substituted Ci-C3o alkylene wherein one or more alkylene units of the Ci-C3o alkylene are optionally and independently replaced by -N(R20)-. -N(R20)C(O)-. -C(O)N(R20)-. - N(R20)S(O)2-, - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, -C(O)O-, -S-, -S(O)-, or -S(O)2-. In some embodiments, S2is selected from an optionally substituted Ci-C3o alky lene wherein one or more alky lene units of the Ci-C3o alkylene are optionally and independently replaced by - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(O)2-. - S(O)2N(R20)-, -O-, -C(O)-. -OC(O)-, - C(O)O-, -S-, — S(O)~ , or -S(O)2- In some embodiments, S2is selected from an optionally substituted C1-C30 alky lene wherein one or more alkylene units of the Ci-C3o alkylene are optionally and independently replaced by -C(O)N(R20)-, -N(R20)S(O)2-, - S(O)2N(R20)-, -O-,— C(0)~ , — OC(O)— , — C(O)O— , -S-, — S(O)~ , or-S(O)2- In some embodiments, S2is selected from an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alky lene are optionally and independently replaced by -N(R20)S(O)2-, - S(O)2N(R20)-, -O-, - C(O)-, — OC(O)— , — C(O)O— , - S- , -S(O)-, or -S(O)2- In some embodiments, S2is selected from an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, -C(O)O-, -S-, -S(O)-, or -S(O)2- In some embodiments, S2is selected from an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alky lene are optionally and independently replaced by -O-, -C(O)-. -OC(O)-, -C(O)O-. -S-, -S(O)-. or - S(O)2-. In some embodiments, S2is selected from an optionally substituted C1-C30 alkylene yvherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -C(O)-, -OC(O)-, -C(O)O-, -S-, -S(O)-, or -S(O)2-.

[0120] In some embodiments, for a Drug-Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I- A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula ( A-l ), S2is selected from an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkydene are optionally and independently replaced by - C(O)-.

[0121] In some embodiments, for a Linker of Formula (XXX), Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), S2is selected from an optionally substituted Ci-Ce alkylene yvherein one or more alkylene units of the Ci-Ce alkylene are optionally and independently replaced by -C(O)-. In some cases, S2is selected from an optionally substituted C1-C2 alky lene wherein one or more alkylene units of the C1-C2 alkylene are optionally and independently replaced by -C(O)-. In some cases, S2is.

[0122] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), S2is selected from - N(R20)-, -N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(O)2- - S(O)2N(R20)-, -O-, -C(O)-, - OC(O)-, -C(O)O-, -S-, -S(O)-, -S(O)2-, 5- to 6-membered heterocyclene, and -P(O)(R20)2- In some cases, S2is selected from -NH-, -NHC(O)-, -C(O)NH-, -NHS(O)2-, - S(O)2NH-, - O- . — C(O)~ , — OC(O)— , — C(O)O— , -S-, — S(O)~ , — S(O)2— , 5- to 6-membered heterocyclene. and - P(O)(R20)2-. In some cases, S2is selected from -NH-, -NHC(O)-, -C(O)NH-, and -C(O)-. In some cases, S2is selected from -NHC(O)-, -C(O)NH-, and -C(O)-. In some cases, S2is selected from -C(O)-.

[0123] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I- A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), -S1-S2-I<1is represented by -S’- Oj-K1.

[0124] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (LA), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), S2is selected from -Ci-Ce alkylene-C(O)-. In some embodiments, S2is selected from -C1-C5 alkylene-C(O)-. In some embodiments, S2is selected from -C1-C4 alkylene-C(O)-. In some embodiments, S2is selected from -C1.C3 alkylene-C(O)-. In some embodiments, S2is selected from -C1.C2 alkylene-C(O)-. In some embodiments, S2is selected from -C2 alkylene-C(O)-. In some embodiments, S2is selected from -C 1 alkylene-C(O)-.

[0125] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I- A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), -S1-S2-K1is

[0126] In some embodiments, a Drug-Linker or salt of Formula (B), Formula (X) orFormula (I) is represented by Formula (I-A):Formula (LA). In some cases. Formula (X) or Formula (I) is represented by Formula (LB):Formula (LB). In some cases, D is exatecan.

[0127] In some embodiments, for a Drug-Linker or salt of Formula (B), Formula (X) or Formula (I), or for a conjugate or salt of Formula (C), Formula (XX) or Formula (A), S3is present and is a phenylene.

[0128] In some embodiments, for a Drug-Linker or salt of Formula (X) or Formula (I), or for a conjugate or salt of Formula (C), Formula (XX) or Formula (A), S3is absent.

[0129] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (LA), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the sugar cleavable unit can refer to a sugar moiety, preferably a glucuronide or a galactoside.

[0130] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (LA), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), cleavage of the cleavable unit triggers self-immolation of the phenyl-comprising linker of the compounds of the invention, and release of the Drug unit (D).

[0131] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (LA), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the peptide cleavable unit can refer to a polypeptide, preferably a dipeptide or a tripeptide.

[0132] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (LA), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the sugar cleavable unit of T1includes a sugar. In some cases, the sugar is glucuronide. In some cases, the sugar is selected from fructose, galactose glucose, xylose and ribose. In some cases, the sugar is amonosaccharide. In some cases, the sugar is a disaccharide. In some cases, the P-glucuronidase enzyme in lysosomes or the tumor interstitium cleaves the drug-linker between the sugar and the oxygen bond, releasing the drug.

[0133] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula ( A- 1), the sugar cleavable unit is cleavable by P-glucuronidase enzyme in lysosomes. In some cases, the sugar cleavable unit is cleavable by P-glucuronidase enzyme in lysosomes under physiological conditions.

[0134] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I- A), or for a conjugate or salt of Formula (C), Formula (XX) or Formula (A), or Formula (some cases, Y1is a sugar moiety. In some cases, Y1is absent.

[0135] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug-Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the peptide unit of T2includes one or more amino acids selected from a group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, sarcosine, serine, threonine, tryptophan, tyrosine, valine, citrulline, and P- Alanine. In some cases, the peptide unit of T2includes one or more amino acids selected from a group consisting of alanine, arginine, asparagine, aspartic acid, glutamine, glycine, lysine, methionine, phenylalanine, proline, serine, valine, citrulline, and P-Alanine. In some cases, the peptide unit of T2includes a dipeptide or tripeptide. In some cases, the peptide unit of T2includes a di peptide. In some cases, the dipeptide is selected from Val-Cit, Val-Ala and Phe-Lys. In some cases, Cathepsin B is a lysosomal cysteine protease that is highly up-regulated in malignant cells. In some cases, the peptide cleavable unit is cleaved by Cathepsin B. In some cases, the peptide cleavable unit is cleavable under physiological conditions by Cathepsin B.

[0136] In some embodiments, for a Linker of Formula (XXX), Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the peptide unit of T2includes a capping moiety. In some cases, the capping moiety is a moiety capable of reacting with an amine of the peptide of to form an amide, carbamate or sulfonamide. In some cases, the capping moiety is a moiety which results from reacting with an amine to form an amide,carbamate or sulfonamide. In some cases, the capping moiety is a moiety which results from reacting with an amine to form an amide. In some cases, the capping moiety is a moiety which0 caps the end of an peptide / amino acid. In some cases, the capping moiety is. In some

[0137] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (LA), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), K1is selected from a peptide unit. In some cases, the peptide unit is a residue.

[0138] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I- A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the peptide unit of K1has 1 to 50 amino acids. In some cases, the peptide unit of K1has 1 to 20 amino acids. In some cases, the peptide unit of K1has 1 to 10 amino acids. In some cases, the peptide unit of K1has 2 to 50 amino acids. In some cases, the peptide unit of K1has 2 to 40 amino acids. In some cases, the peptide unit of K1has 2 to 30 amino acids. In some cases, the peptide unit of K1has 2 to 20 amino acids. In some cases, the peptide unit of K1has 2 to 10 amino acids. In some cases, the peptide unit of K1has 5 to 10 amino acids. In some cases, the peptide unit of K1has at least 1 amino acid. In some cases, the peptide unit of K1has 1 amino acid. In some cases, the peptide unit of K1has at least 2 amino acids. In some cases, the peptide unit of K1has at least 5 amino acids. In some cases, the peptide unit of K1has at least 8 amino acids. In some cases, the peptide unit of K1has at least 10 amino acids. In some cases, the peptide unit of K1has at most 10 amino acids. In some cases, the peptide unit of K1has 10 amino acids. In some cases, the peptide unit of K1has at least 12 amino acids. In some cases, the peptide unit of K1has at most 12 amino acids. In some cases, the peptide unit of K1has at least 20 amino acids. In some cases, the peptide unit of K1has at most 20 amino acids. In some cases, the peptide unit of K1has 20 amino acids. In some cases, the peptide unit of K1has at most 30 amino acids. In some cases, the peptide unit of K1has at least 30 amino acids. In some cases, the amino acids of K1are selected from a group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, sarcosine, serine, threonine, tryptophan, tyrosine, valine, citrulline, and [3-Alanine. In some cases, the amino acids of K1are selected from a group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine,leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, citrulline, and |3-Alanine. In some cases, the amino acids of K1are selected from a group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, citrulline, and 0- Alanine. In some cases, the amino acids of K1are selected from a group consisting of glycine, sarcosine, proline, serine, alanine, and 0-Alanine. In some cases, the amino acids of K1are selected from a group consisting of glycine, proline, serine, alanine, and 0-Alanine. In some cases, the amino acids of K1are selected from a group consisting of glycine, proline, serine, alanine, and 0- Alanine. In some cases, K1includes at least one glycine. In some cases, K1includes at least one proline. In some cases, K1includes at least one serine. In some cases, K1includes at least one alanine. In some cases, K1includes at least one 0-Alanine. In some cases, K1is a polysarcosine. In some cases, K1is a polysarcosine with ten repeating sarcosine units. In some cases, K1only has sarcosines and glycines. In some cases, K1has both one or more sarcosines and one or more glycines. In some cases. K1has both one or more sarcosines and one or more glycines, and no other amino acids.

[0139] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), K1is selected from a peptide unit, wherein the peptide unit has a terminal -NH2. In some cases, K1is selected from a peptide unit, wherein the peptide unit has a terminal -OH. In some cases, K1is selected from a peptide, wherein the peptide has a terminal -NH2. In some cases, K1is selected from a peptide, wherein the peptide has a terminal -OH.

[0140] In some embodiments, for a Linker of Formula (XXX) or Formula (II). for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (LA), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), K1is selected from a peptide unit. In some cases, the peptide unit of K1has 1 to 50 amino acids. In some cases, the peptide unit of K1has 1 to 20 amino acids. In some cases, the peptide unit of K1has 1 to 10 amino acids. In some cases, the peptide unit of K1has 2 to 50 amino acids. In some cases, the peptide unit of K1has 2 to 40 amino acids. In some cases, the peptide unit of K1has 2 to 30 amino acids. In some cases, the peptide unit of K1has 2 to 20 amino acids. In some cases, the peptide unit of K1has 2 to 10 amino acids. In some cases, the peptide unit of K1has 5 to 10 amino acids. In some cases, the peptide unit of K1has at least 1 amino acids. In some cases, the peptide unit of K1has 1 amino acid. In some cases, the peptide unit of K1has at least 2 amino acids. In some cases, the peptide unit of K1has at least 5 amino acids. In some cases, the peptide unit of K1has at least 8 amino acids. In some cases, the peptide unit of K1has at least 10 aminoacids. In some cases, the peptide unit of K1has at most 10 amino acids. In some cases, the peptide unit of K1has 10 amino acids. In some cases, the peptide unit of K1has at least 12 amino acids. In some cases, the peptide unit of K1has at most 12 amino acids. In some cases, the peptide unit of K1has at least 20 amino acids. In some cases, the peptide unit of K1has at most 20 amino acids. In some cases, the peptide unit of K1has 20 amino acids. In some cases, the peptide unit of K1has at most 30 amino acids. In some cases, the peptide unit of K1has at least 30 amino acids. In some cases, K1is a peptide unit selected from a glycine and two adjacent sarcosines. In some cases K1is a peptide unit selected from a glycine and three adjacent sarcosines. In some cases, K1is a peptide unit selected from a glyicine and four adjacent sarcosines. In some cases, when a peptide unit includes adjacent sarcosines, there is at least one other amino acid present. In some cases, K1includes a glycine and two adjacent sarcosines. In some cases, K1includes a glycine and three adjacent sarcosines. In some cases, K1includes a glycine and four adjacent sarcosines. In some cases. K1is a peptide unit selected from a glycine and two adjacent sarcosines. In some cases K1is a peptide unit selected from a glycine and three adjacent sarcosines. In some cases, K1is a peptide unit selected from a glyicine and four adjacent sarcosines. In some cases, K1includes 2 glycines and 8 sarcosines. In some cases, K1includes 3 glycines and 8 sarcosines. In some cases, K1includes 4 glycines and 7 sarcosines. In some cases, K1includes 3 glycines and 7 sarcosines. In some cases. K1includes 3 glycines and 6 sarcosines. In some cases, K1includes 3 glycines and 5 sarcosines. In some cases, K1includes 3 glycines and 4 sarcosines. In some cases, K1includes 3 glycines and 3 sarcosines. In some cases, K1includes 3 glycines and 9 sarcosines. In some cases, K1includes 3 glycines and 10 sarcosines. In some cases, K1includes 5 glycines and 5 sarcosines. In some cases, K1includes 4 glycines and 4 sarcosines. In some cases, K1includes 4 glycines and 5 sarcosines. In some cases, K1includes 5 glycines and 4 sarcosines. In some cases, K1has at most 9 sarcosines. In some cases, K1has at most 8 sarcosines. In some cases, K1has at most 7 sarcosines. In some cases, K1has at most 6 sarcosines. In some cases, K1has at most 5 sarcosines. In some cases, K1has at most 4 sarcosines. In some cases, K1has at most 3 sarcosines. In some cases. K1has at most 2 sarcosines. In some cases, K1has at most 1 sarcosine. In some cases, K1has at most 9 glycines. In some cases, K1has at most 8 glycines. In some cases, K1has at most 7 glycines. In some cases, K1has at most 6 glycines. In some cases, K1has at most 5 glycines. In some cases, K1has at most 4 glycines. In some cases, K1has at most 3 glycines. In some cases, K1has at most 2 glycines. In some cases, K1has at most 1 glycine. In some cases, the amino acids of K1is selected from a group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, sarcosine, serine, threonine, tryptophan, tyrosine, valine, citrulline, and0-Alanine. In some cases, the amino acids of K1is selected from a group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, citrulline, and P-Alanine. In some cases, the amino acids of K1is selected from a group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, try ptophan, ty rosine, valine, citrulline, and -Alanine. In some cases, the amino acids of K1is selected from a group consisting of glycine, sarcosine, proline, serine, alanine, and - Alanine. In some cases, the amino acids of K1is selected from a group consisting of glycine, proline, serine, alanine, and P-Alanine. In some cases, the amino acids of K1is selected from a group consisting of proline, serine, alanine, and P-Alanine. In some cases, the amino acids of K1includes at least one glycine and at least one other amino acid. In some cases, the amino acids of K1includes at least one glycine and at least one sarcosine. In some cases, the amino acids of K1includes at least one glycine and at least one other amino acid selected from proline, serine, alanine, and P-Alanine. In some cases, the amino acids of K1is selected from a group consisting of glycine, proline, serine, alanine, and P-Alanine. In some cases, K1includes at least one glycine. In some cases, K1includes at least one proline. In some cases, K1includes at least one serine. In some cases, K1includes at least one alanine. In some cases. K1includes at least one P- Alanine.

[0141] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), K1includes PASylation. In some cases, PASylation is a peptide compnsing proline, alanine, and serine. In some cases, PASylation is a peptide consisting of only proline, alanine, and serine. In some cases, K1includes PASylation of less than PAS 100. For example, PAS 100 refers to a peptide having 100 amino acids, wherein the amino acids are selected from proline, alanine, and serine. In some cases, K1includes PASylation of less than PAS50. In some cases, K1includes PASylation of less than PAS25. In some cases, K1includes PASylation of more than PAS5. In some cases, K1includes PASylation of more than PAS9. In some cases, K1includes PASylation of more than PAS15. In some cases, K1includes PASylation of PAS5 to PAS25. In some cases, K1includes PASylation of PAS 10 to PAS20. In some cases. K1includes PASylation of PAS 10. In some cases, K1includes PASylation of PAS20. In some cases, K1includes a beta-alanine that links the PASylation to the drug-linker. In some cases, PASylation is used to extend the plasma half-life. In some cases, PASylation is used to increase solubility7. In some cases, PASylation is used to increase solubility without generating secondary structures. In some cases, PASylation isPASylation issome cases, PASylation isAY HYO <YYYYY^rU / »YU H

[0142] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the peptide unit of K1has a terminus unit. In some cases, K1is selected from,wherein the terminus unit is represented by R6, and each j is selected from 1 to 30. In some cases, j is 1. In some cases, j is 3. In some cases, j is 5. In some cases, j is 10. In some cases, j is 20. In some cases, R6is selected from -OR7and -NHR7, wherein R7is selected from hydrogen; C i-io alkyl, C2-10 alkenyl, C2-10 alkynyl, each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, -N(R30)2, -C(O)R30, - C(O)N(R30)2, -N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O-S(O)2OR30. -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =S, =N(R30), -CN, C3-10 carbocycle and 3-to 10-membered heterocycle. In some cases, R6is selected from -OH, -NH2, and. In some cases, R6is -OH. In some cases, R6is -NH2. In some cases, R6is

[0143] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (LA), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the peptide unit of K1has a terminus unit. In some cases, K1is selected fromwherein the terminus unit is represented by R6, and each j is selected from 1 to 30. In some cases, K1is selected fromwherein the terminus unit is represented by R6, and each j is selected from 1 to 30. In some cases, j is 1. In some cases, j is 3. In some cases, j is 5. In some cases, j is 10. In some cases, j is 20. In some cases, R6is selected from -OR7and -NHR7, wherein R7is selected from hydrogen; Ci-io alkyl. C2-10 alkenyl. C2-10 alkynyl. each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, -N(R30)2, -C(O)R30, - C(O)N(R30)2, -N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O- S(O)2OR30. -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =S, =N(R30), -CN, C3-10 carbocycle and 3- to 10-membered heterocycle. In some cases. R6is selected from -OH, and -NH2. In some cases,R6is selected from -OH. -NH2, and. In some cases. R6is -OH. In some cases, R6is -NH2. In some cases,

[0144] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (X), Formula (I), or Formula (LA), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), K1is selected fromsome cases, K1is selected fromIn some cases, K1is selected from. In some cases, K1is selected from. In some cases,K1is selected from. In some cases, K is selected from, ,

[0145] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), K1is selected from

[0146] In some embodiments, for a Linker of Formula (XXX) or Formula (II), for a Drug- Linker or salt of Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), each K1is selected from: an oligosaccharide. In some cases, each K1is selected from:, wherein k is selected from 2 to 10. In some cases, k is 2. In some cases, k is 3. In some cases, k is 4. Insome cases, k is 5. In some cases, k is 6. In some cases, each K1is selected from:

[0147] In some embodiments, for a Drug-Linker or salt of Formula (X), Formula (I), or Formula (I-A), M1is a group which can react with a Targeting Unit to form a connector unit. In some cases, a group that can react with a Targeting Unit to form a connector unit refers to any chemical moiety that is being reactive for covalently binding a Targeting Unit (e.g., antibody, ligand, antigen-binding fragment). In some cases, it may react with a thiol group present on a Targeting Unit. In some cases, it may react with a thiol group present on an antibody or antigenbinding fragment thereof. In some cases, it may react with a thiol group present on a ligand. In some cases, the chemical moieties that are being reactive for covalently binding a ligand includes: carboxylic acid; primary amine; secondary’ amine; tertiary amine; hydroxyl; halogen; activated ester such as N-hydroxysuccinimide ester, perfluorinated esters, nitrophenyl esters, aza-benzotriazole and benzotriazole activated ester, acylureas; alkynyl; alkenyl; azide; isocyanate; isothiocyanate; aldehyde; thiol- reactive moieties such as maleimide, halomaleimides, haloacetyls, pyridyl disulfides; thiol; acrylate; mesylate; tosylate; triflate, hydroxyl amine; chlorosulfonyl; boronic acid - B(OR’)2 derivatives wherein R’ is hydrogen or alkyl group.

[0148] In some cases, M1is selected from maleimide, halogen,?azide,C-CH, activated C=C group ,, OH, SH, activated disulfide group, NH2, and -ONH2. In some cases, M1is maleimide. In some cases, M1is halogen. In some cases, M1isCOOH. In some cases,some cases, M1is azide. In some cases, M1isC-CH. In some cases, the activated C=C group of M1is selected fromsome cases. M1is OH. In some cases, M1is SH. In some cases, the activated disulfide group of M1is selected fromsome cases, M1is. In some cases, M1is NH2. In some cases, M1is -ONH2. In some cases, M1is suitable for click reaction (eg., cyclic alkyne, azide).

[0149] In some embodiments, for a Drug-Linker or salt of Formula (X), Formula (I), orFormula (I -A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), orFormula (A- 1). the Drug unit is selected from a cytotoxic agent, an immune modulatory agent, a nucleic acid, a growth inhibitory agent, a PROTAC. a toxin, a radioactive isotope and a chelating ligand. In some cases, the Drug unit is selected from a cytotoxic agent.

[0150] In some embodiments, for a Drug-Linker or salt of Formula (X), Formula (I), or Formula (I -A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l). the Drug unit is selected from a cytotoxic agent, camptothecin derivative, and an immune modulatory agent.

[0151] In some cases, the Drug unit is selected from exatecan, SN-38, and monomethyl auristatin E (MMAE). In some cases, Drug unit is a camptothecin derivative. In some cases, Drug unit is exatecan. In some cases, Drug unit is SN-38. In some cases, Drug unit is selected from MMAF and MMAE. In some cases, the cytotoxic agent is selected from the group consisting of an auristatin, a maytansinoid, a camptothecin, a duocarmycin, and a calicheamicin. In some cases, a cytotoxic agent is an agent that has a cytotoxic effect on a cell. In some cases, cytotoxic agents include, for example, tubulin disrupting agents, topoisomerase inhibitors, DNA minor groove binders, and DNA alkylating agents. In some cases, tubulin disrupting agents include, for example, auristatins, dolastatins, tubulysins, colchicines, vinca alkaloids, taxanes,cryptophycins, maytansinoids, hemiasterlins, as well as other tubulin disrupting agents. In some cases, auristatins are derivatives of the natural product dolastatin 10. In some cases, auristatins are selected from MMAE (N-methylvaline-valine-dolaisoleuine-dolaproine-norephedrine), MMAF (N-methylvaline-valine-dolaisoleuine-dolaproine-phenylalanine) and AFP. In some cases, a cytotoxic agent can be a topoisomerase inhibitor. In some cases, a drug is an immune modulatory agent, such as a TLR7 and / or TLR8 agonist. In some cases, an immune modulatory agent is a STING agonist. In some cases, a drug is a radioactive atom. In some cases, a drug is a proteolysis targeted chimera (PROTAC).

[0152] In some embodiments, for a Drug-Linker or salt of Formula (X), Formula (I), or Formula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A- 1), S3is selected from a spacer. In some cases, the spacer is a divalent moiety that covalently binds two components of the conjugate or Drug-Linker. In some cases, S3is present. In some cases, S3is absent. In some cases, the spacer is selected from: alkylene, heteroalkylene (an alkylene having one or more alkylene units replaced by at least one heteroatom selected from Si, N, O and S, with the appropriate valency); alkoxy; polyether such as polyalkylene glycol and typically polyethylene glycol; one or more natural or non-natural aminoacids such as glycine, alanine, proline, valine, N-methylglycine; Cs-Cs heterocyclo; Cs-Cs carbocyclo; arylene, and any combination thereof. In some cases, a spacer is a divalent linear alkylene group. In some cases, the spacer can be selected from the group consisting of-Ci-Cio alkylene-, -Ci- Cio heteroalkylene-, -C3-C8 carbocyclo-, -O-(Ci Cs alkyl)-, -arylene-, -Ci-Cio alkylene-arylene-, -arylene-Ci-Cio alkylene-, -Ci-Cio alkylene-(C3-Cs carbocyclo)-, - (Cs-Cs carbocyclo)-Ci- Cio alkylene-, -Cs-Cs heterocyclo-, -Ci-Cio alkylene-(C3-Cs heterocyclo)-, -(C3-Cs heterocyclo)-Ci-Cio alkylene-. -C1-C10 alkylene-C(=O)-, -Ci- C10 heteroalkylene-C(=O)-, - C3-C8 carbocyclo-C(=O)-, -O-(Ci-Cs alkyl)-C(=O)-, - arylene-C(=O)-, -C1-C10 alkylene-arylene- C(=O)-, -arylene-Ci-Cio alkylene-C(=O)-, -Ci- C10 alkylene-(C3-Cscarbocyclo)-C(=O)-, -(C3- Cs carbocyclo)-Ci-Cio alkylene-C(=O)-, - C3-C8 heterocyclo-C(=O)-, -C1-C10 alkylene-(C3- C8heterocyclo)-C(=O)-, -(C3-C8 heterocyclo)-Ci-Cio alkylene-C(=O)-, -C1-C10 alkylene-NH-, - C1-C10 heteroalkyl ene-NH-, -C3-C8 carbocyclo-NH-, -O-(Ci-Cs alkyl)-NH-, -arylene-NH-, -Ci- C10 alkydene- arylene-NH-, -arylene-Ci-Cio alkylene-NH-, -C1-C10 alkylene-(C3-Cs carbocyclo)- NH-, - (C3-C8 carbocyclo)-Ci-Cio alkylene-NH-, -Cs-Csheterocyclo-NH-, -C1-C10 alkylene-(C3- Cs heterocyclo)-NH-, -(C3-C8 heterocyclo)-Ci-Cio alkylene-NH-, -C1-C10 alkylene-S-, - Ci- C10 heteroalkylene-S -, -Cs-Cscarbocyclo-S -, -O-(Ci-Cs alkyl)-)-S -, -arylene-S-, -Ci-C10 alkylene-arylene-S-, -arylene-Ci-Cio alkylene-S-, -C1-C10 alkylene-(C3- Cs carbocyclo)-S-, - (C3-C8 carbocyclo)-Ci-Cio alkylene-S-, -C3-C8 heterocyclo-S-, -Ci- C10 alkylene-(C3-Cs heterocyclo)-S-, -(C3-C8 heterocyclo)-Ci-Cio alkylene-S-, -C1-C10 alkylene-O-C(=O)-, -C3-C8carbocyclo-O-C(=O)-, -O-(Ci-C8alkyl)-O-C(=O)-, -arylene- O-C(=O)-, -C1-C10 alkylene- arylene-O-C(=O)-, -arylene-Ci-Cio alkylene-O-C(=O)-, -Ci- Cio alkylene-(C3-C8carbocyclo)-O- C(=O)-,-(C3-C8carbocyclo)-Ci-Cio alkylene-O-C(=O)-, -C3-C8heterocyclo-O-C(=O)-, -Ci- Cio alkylene-(C3-C8heterocyclo)-O-C(=O)-, and -(C3-C8heterocyclo)-Ci-Cio alkylene-O-C(=O)- . In some cases, S3is optionally substituted with one or more of the substituents selected from (i) halogen, -OR30, -N(R30)2, -SR30, -N(R30)2, -C(O)R30, -C(O)N(R30)2, -N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -O-S(O)2R30, -S(O)2R30, -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =s, =N(R30), and -CN; (ii) Ci -10 alkyl, C2-10 alkenyl, C2-10 alkynyl, each of which is optionally substituted with one or more substituents independently selected from halogen. -OR30, -SR30, - N(R30)2, -C(O)R30, -C(0)N(R30)2, -N(R30)C(0)R30. -C(0)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O-S(O)2OR30, -P(O)(OR30)2, -OP(O)(OR30)2, -N02, =0, =S, =N(R30), -CN, C3-io carbocycle and 3- to 10-membered heterocycle; and (iii) C3-io carbocycle and 3- to 10-membered heterocycle each of which is optionally substituted with one or more substituents independently selected from halogen. -OR30, -SR30, -N(R30)2, -C(O)R30, -C(O)N(R30)2, - N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -P(O)(OR30)2, -OP(O)(OR30)2, - N02, =0, =S, =N(R30), -CN, C1-6 alkyl, C2-6 alkenyl, and C2-6 alkynyl. In some cases, S3is optionally substituted with one or more of the substituents selected from (i) halogen, -OR30, - N(R30)2, -SR30. -N(R30)2. -C(O)R30, -C(O)N(R30)2. -N(R30)C(O)R30. -C(O)OR30. -OC(O)R30, - S(O)R30, -O-S(O)2R30, -S(O)2R30, -P(O)(OR30)2, -OP(O)(OR30)2, -N02, =0, =S, =N(R30), and -CN. In some cases, S3is unsubstituted. In some cases, S3is substituted. In some cases, S3is a phenylene. In some cases,

[0153] In some embodiments, for a Drug-Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A). further includes attaching a Targeting Unit to M1to form a conjugate, wherein M1of the Drug-Linker reacts and forms a covalent bond to the Targeting Unit. In some cases, the Targeting unit is selected from an antibody or an antigen-binding portion thereof. In some cases, the conjugate has an average ratio of Drug-Linker to Targeting unit of about 1 to 10. In some cases, the Targeting unit is selected from an antibody or an antigen-binding portion thereof. In some cases, the conjugate has an average ratio of Drug- Linker to Targeting unit of about 1 to 10. In some cases, the conjugate has an average ratio of Drug-Linker to Targeting unit of about 1 to 5. In some cases, the conjugate has an average ratio of Drug-Linker to Targeting unit of about 1, about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9. or about 10.

[0154] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l ), D is drug unit. In some cases, D includes a spacer. In somecases, the spacer is a divalent moiety that covalently attaches the drug to the linker. In some cases, the spacer is a divalent moiety that covalently attaches the drug to the rest of the molecule. In some cases, D does not include a spacer. In some cases, the spacer can be selected from the group consisting of-Ci-Cio alkylene-, -C1-C10 heteroalkylene-, -Cs-Cs carbocyclo-, - O-(Ci C8alkyl)-, -arylene-, -C1-C10 alkylene-arylene-, -arylene-Ci-Cio alkylene-, -Ci- Cio alkylene-(C3-C8carbocyclo)-, -(Cs-C8carbocyclo)-Ci-Cio alkylene-, -Cs-Cs heterocyclo-, - C1-C10 alkylene-(C3-Cs heterocyclo)-, -(C3-C8 heterocyclo)-Ci-Cio alkylene-, -C1-C10 alkylene- C(=O)-, -C1-C10 heteroalkylene-C(=O)-, -C3-C8carbocyclo-C(=O)-, -O-(Ci-C8alkyl)-C(=O)-, - arylene-C(=O)-, -C1-C10 alkylene-arylene-C(=O)-, -arylene-Ci-Cio alkylene-C(=O)-, -Ci- C10 alkylene-(C3-C8carbocyclo)-C(=O)-, -(C3-C8carbocyclo)-Ci-Cio alkylene-C(=O)-, - C3- C8heterocyclo-C(=O)-, -C1-C10 alkylene-(C3-C8heterocyclo)-C(=O)-, -(C3-C8heterocyclo)-Ci- C10 alkylene-C(=O)-, -C1-C10 alkylene-NH-, -C1-C10 heteroalkylene-NH-, -C3-C8carbocyclo- NH-, -O-(Ci-C8alkyl)-NH-, -arylene-NH-, -C1-C10 alkylene- arylene-NH-, -arylene-Ci- C10 alkylene-NH-, -C1-C10 alkylene-(C3-C8carbocyclo)-NH-. - (C3-C8carbocyclo)-Ci- C10 alkylene-NH-, -C3-C8heterocyclo-NH-, -C1-C10 alkylene-(C3- C8heterocyclo)-NH-, -(C3- C8heterocyclo)-Ci-Cio alkylene-NH-, -C1-C10 alkylene-S-, - C1-C10 heteroalkylene-S -, -C3- C8carbocyclo-S -, -O-(Ci-C8alkyl)-)-S-, -arylene-S-, -Ci- C10 alkylene-arylene-S-, -arylene-Ci- C10 alkylene-S-, -C1-C10 alkylene-(C3- C8carbocyclo)-S-. -(Cs-C8carbocyclo)-Ci-Cio alkylenes', -C3-C8heterocyclo-S-, -Ci- C10 alkylene-(C3-C8heterocyclo)-S-, -(C3-C8heterocyclo)-Ci- C10 alkylene-S-, -C1-C10 alkylene-O-C(=O)-, -C3-CS carbocyclo-O-C(=O)-, -O-(Ci-C8alkyl)-O- C(=O)-, -arylene- O-C(=O)-, -C1-C10 alkylene-arylene-O-C(=O)-, -arylene-Ci-Cio alkylene-O- C(=O)-, -Ci- C10 alkylene-(C3-C8carbocyclo)-O-C(=O)-,-(C3-C8carbocyclo)-Ci-Cio alkylene-O- C(=O)-, -C3-C8heterocyclo-O-C(=O)-, -C1-C10 alkylene-(C3-C8heterocyclo)-0-C(=0)-, and - (Cs-C8heterocyclo)-Ci-Cio alkylene-O-C(=O)-. In some cases, the spacer can be selected from the group consisting of-Ci-Cio alkylene-, and -C1-C10 alkylene-NH-. In some cases, the drug unit is only a drug.

[0155] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), M2is a connector unit. In some cases, the connector unit refers to a component that connects different parts of the conjugate together. In some cases, the connector unit can connect the Targeting Unit to S3(if present) or to S1. In some cases, the connector unit forms a bond with a sulfur atom of a Targeting unit. In some cases, the connector unit forms a bond with a sulfur atom of a Targeting unit via a maleimide group. In some cases, the sulfur atom can be derived from, for example, a sulfhydryl group of a Targeting unit (e.g., athiol group of an interchain disulfide bond). In some cases,some cases, M2in some cases, M2isIn some cases, M2isIn some cases, M2is -CH2-C(O)NH-. In some cases, M2is linked to the Targeting unit via a disulfide bond between a sulfur atom of M2and a sulfur atom of the Targeting unit. In some cases, M2is H. in some cases, the connector unit forms a bond with a primary or secondary amino group of a Targeting unit. In

[0156] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX),Formula (A), or Formula (A-l), the Targeting unit is an anti-PTK7 antibody or an antigenbinding portion thereof. In some cases, L is an anti-PTK.7 antibody. In some cases, the PTK7 antibody is modified with a group capable of reacting to form M2(e.g., to formgroup capable of a click reaction to form M2(e.g., to form

[0157] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the Targeting unit is an anti-PTK7 antibody or an antigenbinding portion thereof. In some cases, L is an anti-PTK7 antibody. In some cases, the anti- PTK7 antibody comprises 8 sulfur atoms that each can independently form a bond with about eight separate drug-linkers via M2.

[0158] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), L is an anti-PTK7 antibody or an antigen-binding portion thereof. In some cases, the anti-PTK7 antibody is selected from PTK7-1; PTK7-1EL; PTK7-2; L is PTK7-3; L is PTK7-4; PTK7-5; PTK7-6; PTK7-7; PTK7-8; PTK7-9; PTK7-9EL; PTK7-10; PTK7-11; PTK7-12; PTK7-13; and PTK7-14. In some cases, L is PTK7-1EL. In some cases, L is PTK7-2. In some cases, L is PTK7-3. In some cases, L is PTK7-4. In some cases, L is PTK7- 5. In some cases, L is PTK7-6. In some cases, L is PTK7-7. In some cases, L is PTK.7-8. In some cases, L is PTK7-9. In some cases, L is PTK7-10. In some cases, L is PTK7-11. In some cases, L is PTK7-12. In some cases, L is PTK7-13. In some cases, L is PTK7-14.

[0159] In some embodiments, the conjugate of Formula (XX) is represented byFormu ,la ( ,XYXY,), or a pharmaceutically acceptable salt thereof, wherein the DAR is a drug to Targeting Unit (L) ratio. In some cases, the DAR is a drug to antibody ratio. In some cases, the DAR is about 1 to about 10. In some cases, the DAR is about 2 to about 10. In some cases, the DAR is about 4. In some cases, the DAR is about 8.

[0160] In some embodiments, the conjugate of Formula (XX) is represented byFormu ,la ( / XYXV)., or a pharmaceutically acceptable salt thereof, wherein the DAR is a drug to Targeting Unit (L) ratio and S is a sulfur atom. In some cases, the DAR is a drug to antibody ratio. In some cases, the DAR is about 1 to about 10. In some cases, the DAR is about 2 to about 10. In some cases, the DAR is about 4. In some cases, the DAR is about 8.

[0161] In some embodiments, the conjugate of Formula (XX) is represented byFormula (A), or a pharmaceutically acceptable salt thereof, wherein the DAR is a drug to Targeting Unit (L) ratio. In some cases, the DAR is a drug to antibody ratio. In some cases, the DAR is about 1 to about 10. In some cases, the DAR is about 2 to about 10. In some cases, the DAR is about 4. In some cases, the DAR is about 8.

[0162] In some embodiments, the conjugate of Formula (XX) is represented byor a pharmaceutically acceptable salt thereof, wherein:L is a Targeting Unit, wherein the Targeting Unit is an anti-PTK7 antibody or an antigen-binding portion thereof;K1is a peptide unit;DAR is an integer selected from about 1 to about 12; andM2is selected fromD is a cytotoxic agent. In some cases, D is selected from exatecan, MMAE, and MMAF. Insome cases, the DAR is about 1 to about 10. In some cases, the DAR is about 4. In some cases, the DAR is about 8. In some cases. L is selected from PTK7-1; PTK7-1EL; PTK7-2; L is PTK7-3; L is PTK7-4; PTK7-5; PTK7-6; PTK7-7;PTK7-8; PTK7-9; PTK7-9EL; PTK7-10; PTK7-11; PTK7-12; PTK7-13; and PTK7-14. In some cases, L is PTK7-1EL. In some cases, L is PTK7-2. In some cases, L is PTK7-3. In some cases,L is PTK7-4. In some cases, L is PTK7-5. In some cases, L is PTK7-6. In some cases, L isPTK7-7. In some cases, L is PTK7-8. In some cases, L is PTK7-9. In some cases, L is PTK7-10.In some cases, L is PTK7-11. In some cases, L is PTK7-12. In some cases, L is PTK7-13. In some cases, L is PTK7-14. In some cases, Y1isIn some cases. M2issome cases, the peptide unit of K1has 1 to 50 amino acids, wherein the amino acids of K1is selected from the group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, sarcosine, serine, threonine, tryptophan, tyrosine, valine, citrulline, and P-Alanine. In some cases, the amino acids of K1is selected from the group consisting of glycine, sarcosine, proline, serine, and P-Alanine. In some cases, the amino acids of K1is selected from the group consisting of glycine, sarcosine. In some cases, K1is selected fromsome cases, K1is a peptoid.

[0163] In some embodiments, the conjugate of Formula (XX) is represented byor a pharmaceutically acceptable salt thereof, whereinDAR is an integer selected from about 1 to about 12;K1is a peptide unit;S is a sulfur atom. In some cases,In some cases, M2is. In some cases. D is a cytotoxic agent. In some cases, D is selected from exatecan, MMAE, and MMAF. In some cases, D isthe DAR is about 1 to about 10. In some cases, the DAR is about 4. In some cases, the DAR is about 8. In some cases, L is selected from PTK7-1; PTK7-1EL; PTK7-2; L is PTK7-3; L isPTK7-4; PTK7-5; PTK7-6; PTK7-7; PTK7-8; PTK7-9; PTK7-9EL; PTK7-10; PTK7-11; PTK7- 12; PTK7-13; and PTK7-14. In some cases, L is PTK7-1EL. In some cases, L is PTK7-2. In some cases, L is PTK7-3. In some cases, L is PTK7-4. In some cases, L is PTK.7-5. In some cases, L is PTK7-6. In some cases, L is PTK7-7. In some cases, L is PTK7-8. In some cases, L is PTK7-9. In some cases, L is PTK7-10. In some cases, L is PTK7-11. In some cases, L is PTK7- 12. In some cases, L is PTK7-13. In some cases, L is PTK7-14. In some cases, Y1is, some cases, the peptide unit of K1has 1 to 50 amino acids, wherein the amino acids of K1is selected from the group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, sarcosine, serine, threonine, tryptophan, tyrosine, valine, citrulline, and 0- Alanine. In some cases, the amino acids of K1is selected from the group consisting of glycine, sarcosine, proline, serine, and 0- Alanine. In some cases, the amino acids of K1is selected from the group consisting of glycine, sarcosine. In some cases, K1is selected from

[0164] In some embodiments, the conjugate of Formula (XX) is represented by

[0165] or a pharmaceutically acceptable salt thereof, wherein the DAR is a drug to Targeting Unit (L) ratio. In some cases, the DAR is a drug to antibody ratio. In some cases, the DAR is about 1 to about 10. In some cases, the DAR is about 4. In some cases, the DAR is about 8.

[0166] In some embodiments, the conjugate of Formula (XX) is represented byFormu .la ( .A.-l). or a pharmaceutically acceptable salt thereof, wherein the DAR is a drug to Targeting Unit (L) ratio and S is a sulfur atom. In some cases, the DAR is a drug to antibody ratio. In some cases,the DAR is about 1 to about 10. In some cases, the DAR is about 4. In some cases, the DAR is about 8.

[0167] In an aspect, the present disclosure provides a Linker of Formula (XXX):Formula (XXX) or a pharmaceutically acceptable salt thereof, wherein;Y1is absent or selected from -O-T1and -NH-T2:T1is a sugar cleavable unit;T2is a peptide cleavable unit;51is selected from: (i) an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(0)2- - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, - C(O)O-, -S-, -S(O)-, -S(O)2- 5- to 6-membered heterocyclene, or -P(O)(R20)2-; (ii) optionally substituted C3-C30 alkenylene, wherein one or more alkenylene units of the C3-C30 alkenylene are optionally and independently replaced by -N(R20)-, -N(R20)C(O)-. - C(O)N(R20)-, -N(R20)S(0)2- - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, -C(O)O- -S-, -S(O)-, -S(O)2- or -P(O)(R20)2; (iii) one or more amino acid(s); (iv) one or more N-substituted amino acid(s); (v) optionally substituted poly ether; (vi) optionally substituted C3-C10 carbocyclene; (vii) optionally substituted 5- to 10-membered heterocyclene;52is selected from an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(O)2-, - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, - C(O)O-, -S-, — S(O)~ , -S(O)2-, 5- to 6-membered heterocyclene, or -P(O)(R20)2-;53is selected from a spacer, wherein S3is present or absent: wherein the optional substituents on M1, K1, S1, S2, and S3, are independently selected at each occurrence from:(i) halogen, -OR30, -N(R30)2, -SR30, -N(R30)2, -C(O)R30, -C(O)N(R30)2, - N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30. -O- S(O)2OR30. -P(O)(OR30)2, -OP(O)(OR30)2. -NO2, =0, =S. =N(R30), and -CN;(ii) Ci-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, -N(R30)2, -C(O)R30, - C(O)N(R30)2, -N(R30)C(0)R30, -C(0)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O-S(O)2OR30, -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =S, =N(R30), -CN, C3-10 carbocycle and 3- to 10-membered heterocycle; and(iii) C3-10 carbocycle and 3- to 10-membered heterocycle each of which is optionally substituted with one or more substituents independently selected from halogen. -OR’". -SR30, - N(R30)2, -C(O)R30. -C(0)N(R30)2, -N(R30)C(0)R30-C(O)OR30, -OC(O)R30. -S(O)R30, - S(O)2R30, -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =S, =N(R30), -CN, Ci-6alkyl, C2-6 alkenyl, and C2-6 alkynyl;M1is a group which can react with a ligand to form a connector unit;K1is selected from:(i) a peptide unit,(ii) an oligosaccharide; and(iii) a poly ether; each R20is independently selected from hydrogen; and C1-6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, -N02, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl, -O-Ci-10 alky l, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle; and each R30is independently selected from hydrogen; and C1-6 alkyl, C2-6 alkenyl, C2-6 alky my 1, C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen, -OH, -CN, -N02, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl, -O-Ci-10 alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle ; andR50is selected from a substituent capable of reacting with a nucleophilic group on a Drug.

[0168] In some cases, a linker of Formula (XXX) is represented byFormula (II) or a pharmaceutically acceptable salt thereof.

[0169] In some cases, for a linker of Formula (XXX) or Formula (II), R50is selected from - orTOH. In some cases, for a linker of Formula (II), R30is selected from Cl

[0170] In some cases, for a linker of Formula (XXX) or Formula (II), R50is selected from

[0171] In some embodiments, a Drug-Linker of Formula (X) or Formula (I) is selected from:

[0172] In some embodiments, a Drug-Linker of Formula (X) or Formula (I) is selected from:

[0173] In some embodiments, a Drug-Linker of Formula (X) or Formula (I) is selected from:

[0174] In some embodiments, a Drug-Linker of Formula (X) or Formula (I) is selected from:

[0175] In some embodiments, a conjugate of Formula (XX) or Formula (A), is represented by:wherein each L is a Targeting Unit; and each DAR is a drug to antibody ratio. In some cases, the DAR is determined using RP-HPLC. In some cases, the DAR is determined using RP-HPLC as in example 24. In some cases, the DAR is at most about 16. In some cases, the DAR is about 8. In some cases, the DAR is 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, L is an antibody. In some cases, L is a PTK7 antibody. In some cases, L is a PTK7 antibody having VHSEQ ID NO: 193 and VLSEQ ID NO: 188.

[0176] In some embodiments, a conjugate of Formula (XX) or Formula (A), is represented by:, wherein each L is a Targeting Unit; and each DAR is a drug to antibody ratio. In some cases, the DAR is determined using RP-HPLC. In some cases, the DAR is determined using RP-HPLC as in example 24. In some cases, the DAR is at most about 16. In some cases, the DAR is about 8. In some cases, the DAR is 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, L is an antibody. In some cases, L is a PTK7 antibody. In some cases, L is a PTK7 antibody having VHSEQ ID NO: 193 and VLSEQ ID NO: 188.

[0177] In some embodiments, a conjugate of Formula (XX) or Formula (A), is represented by the structurewherein:wherein PTK7 is an anti-PTK7 antibody or an antigen-binding portion thereof; D is a Drug unit; and DAR is a drug to antibody ratio. In some cases, the DAR is determined using RP-HPLC. In some cases, the DAR is determined using RP-HPLC as in example 24. In some cases, the DAR is at most about 16. In some cases, the DAR is about 8. In some cases, the DAR is 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 2. In some cases, the DAR is about 3. In some cases, the DAR is about 4. In some cases, the DAR is about 5. In some cases, the DAR is about 6. In some cases, the DAR is about 7. In some cases, the DAR is about 8. In some cases, DAR is a drug (D) to antibody (L) ratio. In some cases, the Drug unit (D) is exatecan. In some cases, D is MMAE. In some cases, D is SN-38. In some cases, the drug of the DAR is exatecan. In some cases, the drug of the DAR is exatecan. In some cases, (PTK7) is a PTK7 antibody or an antigen-binding fragment thereof. In some cases, the PTK7 antibody is selected from Table 7. In some cases, the PTK7 antibody is a PTK7 antibody having VHSEQ ID NO: 193 and VLSEQ ID NO: 188.

[0178] In some embodiments, a conjugate of Formula (XX) or Formula (A), is represented by the structurewherein:wherein PTK7 is a PTK7 antibody or antigen binding portion thereof; D is a Drug unit; and DAR is a drug to antibody ratio. In some cases, the DAR is determined using RP-HPLC. In some cases, the DAR is determined using RP-HPLC as in example 24. In some cases, the DAR is at most about 16. In some cases, the DAR is about 8. In some cases, the DAR is 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 about 2. In some cases, the DAR is about 3. In some cases, the DAR is about 4. In some cases, the DAR is about 5. In some cases, the DAR is about 6. In some cases, the DAR is about 7. In some cases, the DAR is about 8. In some cases, the DAR is from about 6 to about 8. In some cases, DAR is a drug (D) to antibody (L) ratio. In some cases, the Drug unit (D) is exatecan. In some cases, D is MMAE. In some cases, D is SN-38. In some cases, the drug of the DAR is exatecan. In some cases, the drug of the DAR is exatecan. In some cases, (PTK7) is a PTK7 antibody or an antigen-binding fragment thereof. In some cases, the PTK7 antibody is selected from Table 7. In some cases, the PTK7 antibody is a PTK7 antibody having VHSEQ ID NO: 193 and VLSEQ ID NO: 188.

[0179] In some embodiments, a conjugate of Formula (XX) or Formula (A), is represented bv the structurewherein:wherein PTK.7 is a PTK7 antibody or antigen binding portion thereof; D is a Drug unit; and DAR is a drug to antibody ratio. In some cases, the DAR is determined using RP-HPLC. In some cases, the DAR is determined using RP-HPLC as in example 24. In some cases, the DAR is at most about 16. In some cases, the DAR is about 8. In some cases, the DAR is 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 about 2. In some cases, the DAR is about 3. In some cases, the DAR is about 4. In some cases, the DAR is about 5. In some cases, the DAR is about 6. In some cases, the DAR is about 7. In some cases, the DAR is about 8. In some cases, the DAR is from about 6 to about 8. In some cases, DAR is a drug (D) to antibody (L) ratio. In some cases, the Drug unit (D) is exatecan. In some cases, D is MMAE. In some cases, D is SN-38. In some cases, the drug of the DAR is exatecan. In some cases, the drug of the DAR is exatecan. In some cases, (PTK7) is a PTK7 antibody or an antigen-binding fragment thereof. In some cases, the PTK7 antibody is selected from Table 7. In some cases, the PTK7 antibody is a PTK.7 antibody having VHSEQ ID NO: 193 and VLSEQ ID NO: 188.

[0180] In some embodiments, a conjugate of Formula (XX) or Formula (A), is representedby the structure of wherein:wherein PTK7 is a PTK7 antibody or antigen binding portion thereof; D is a Drug unit; and DAR is a drug to antibody ratio. In some cases, the DAR is determined using RP-HPLC. In some cases, the DAR is determined using RP-HPLC as in example 24. In some cases, the DAR is at most about 16. In some cases, the DAR is about 8. In some cases, the DAR is 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 about 2. In some cases, the DAR is about 3. In some cases, the DAR is about 4. In some cases, the DAR is about 5. In some cases, the DAR is about 6. In some cases, the DAR is about 7. In some cases, the DAR is about 8. In some cases, the DAR is from about 6 to about 8. In some cases, DAR is a drug (D) to antibody (L) ratio. In some cases, the Drug unit (D) is exatecan. In some cases, D is MMAE. In some cases, D is SN-38. In some cases, the drug of the DAR is exatecan. In some cases, (PTK7) is a PTK7 antibody or anantigen-binding fragment thereof. In some cases, the PTK7 antibody is selected from Table 7. In some cases, the PTK7 antibody is a PTK7 antibody having VH SEQ ID NO: 193 and VL SEQ ID NO: 188.

[0181] In some embodiments, a conjugate of Formula (XX) or Formula (A), is representedby the structure of wherein:wherein PTK7 is a PTK7 antibody or antigen binding portion thereof; D is a Drug unit; and DAR is a drug to antibody ratio. In some cases, the DAR is determined using RP-HPLC. In some cases, the DAR is determined using RP-HPLC as in example 24. In some cases, the DAR is at most about 16. In some cases, the DAR is about 8. In some cases, the DAR is 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 2. In some cases, the DAR is about 3. In some cases, the DAR is about 4. In some cases, the DAR is about 5. In some cases, the DAR is about 6. In some cases, the DAR is about 7. In some cases, the DAR is about 8. In some cases, DAR is a drug (D) to antibody (L) ratio. In some cases, the Drug unit (D) is exatecan. In some cases, D is MMAE. In some cases, D is SN-38. In some cases, the drug of the DAR is exatecan. In some cases, (PTK7) is a PTK7 antibody or an antigen-binding fragment thereof. In some cases, the PTK7 antibody is selected from Table 7. In some cases, the PTK7 antibody is a PTK7 antibody having VH SEQ ID NO: 193 and VL SEQ ID NO: 188.

[0182] In some embodiments, a conjugate of Formula (XX) or Formula (A), is representedby the structure of wherein:wherein PTK7 is a PTK7 antibody or antigen binding portion thereof D is a Drug unit; and DAR is a drug to antibody ratio. In some cases, the DAR is determined using RP-HPLC. In some cases, the DAR is determined using RP-HPLC as in example 24. In some cases, the DAR is at most about 16. In some cases, the DAR is about 8. In some cases, the DAR is 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 2. In some cases, the DAR is about 3. In some cases, the DAR is about 4. In some cases, the DARis about 5. In some cases, the DAR is about 6. In some cases, the DAR is about 7. In some cases, the DAR is about 8. In some cases, DAR is a drug (D) to antibody (L) ratio. In some cases, the Drug unit (D) is exatecan. In some cases, D is MMAE. In some cases, D is SN-38. In some cases, the drug of the DAR is exatecan. In some cases, the drug of the DAR is exatecan. In some cases, (PTK7) is a PTK7 antibody or an antigen-binding fragment thereof. In some cases, the PTK7 antibody is selected from Table 7. In some cases, the PTK7 antibody is a PTK7 antibody having VHSEQ ID NO: 193 and VLSEQ ID NO: 188.Table AA-1: Specific Conjugates of the DisclosureIn some embodiments, the conjugates of Table AA-1 have a DAR selected from about 1 to about 8. In some cases, the DAR is selected from about 2 to about 8. In some cases, the DAR is selected from about 4 to about 8. In some cases, the DAR is selected from about 2 to about 6. In some cases, the DAR is selected from about 2 to about 4. In some cases, the DAR is selected from about 6 to about 8. In some cases, the DAR is about 2. In some cases, the DAR is about 3. In some cases, the DAR is about 4. In some cases, the DAR is about 5. In some cases, the DAR is about 6. In some cases, the DAR is about 7. In some cases, the DAR is about 8.Table AA-1*:

[0183] DAR, L, and R are as defined in Table AA-1. S is a sulfur atom.Table AA-2: Specific Conjugates of the Disclosure-Ill-

[0184] In some embodiments, the conjugates of Table AA-2 have a DAR selected from about 1 to about 8. In some cases, the DAR is selected from about 2 to about 8. In some cases, the DAR is selected from about 4 to about 8. In some cases, the DAR is selected from about 2 to about 6. In some cases, the DAR is selected from about 2 to about 4. In some cases, the DAR is selected from about 6 to about 8. In some cases, the DAR is about 2. In some cases, the DAR isabout 3. In some cases, the DAR is about 4. In some cases, the DAR is about 5. In some cases, the DAR is about 6. In some cases, the DAR is about 7. In some cases, the DAR is about 8.Table AA-2*:

[0186] Included in the present disclosure are salts, particularly pharmaceutically acceptable salts, of the compounds described herein. The compounds of the present invention that possess a sufficiently acidic, a sufficiently basic, or both functional groups, can react with any of a number of inorganic bases, and inorganic and organic acids, to form a salt. Alternatively, compounds that are inherently charged, such as those with a quaternary nitrogen, can form a salt with an appropriate counterion, e.g., a halide such as bromide, chloride, or fluoride, particularly bromide.

[0187] Chemical entities having carbon-carbon double bonds or carbon-nitrogen double bonds may exist in Z- or E- form (or cis- or trans- form). Furthermore, some chemical entities may exist in various tautomeric forms. Unless otherwise specified, compounds described herein are intended to include all Z-, E- and tautomeric forms as well.

[0188] A “tautomer’" refers to a molecule wherein a proton shift from one atom of a molecule to another atom of the same molecule is possible. The compounds presented herein, in certain embodiments, exist as tautomers. In circumstances where tautomerization is possible, a chemical equilibrium of the tautomers will exist. The exact ratio of the tautomers depends on several factors, including physical state, temperature, solvent, and pH. Some examples of tautomeric equilibrium include:

[0189] The compounds disclosed herein, in some embodiments, are used in different enriched isotopic forms, e.g., enriched in the content of2H,3H,nC.13C and / or14C. In one particular embodiment, the compound is deuterated in at least one position. Such deuterated forms can be made by the procedure 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 the metabolic stability and or efficacy, thus increasing the duration of action of drugs.

[0190] Unless otherwise stated, compounds described herein are intended to include compounds which differ only in the presence of one or more isotopically enriched atoms. For example, compounds having the present structures except for the replacement of a hydrogen by a deuterium or tritium, or the replacement of a carbon by13C- or14C-enriched carbon are within the scope of the present disclosure.

[0191] The compounds of the present disclosure optionally contain unnatural proportions of atomic isotopes at one or more atoms that constitute such compounds. For example, the compounds may be labeled with isotopes, such as for example, deuterium (2H), tritium (3H), iodine-125 (125I) or carbon-14 (14C). Isotopic substitution with2H,nC,13C.14C,15C,12N,13N,15N,16N,16O,17O,14F.15F.16F,17F,18F,33S.34S,35S,36S,35C1,37C1.79Br.81Br, and125I are all contemplated. All isotopic variations of the compounds of the present invention, whether radioactive or not, are encompassed within the scope of the present invention.

[0192] In certain embodiments, the compounds disclosed herein have some or all of theatoms replaced with2H atoms. The methods of synthesis for deuteri um-containing compounds are known in the art and include, by way of non-limiting example only, the following synthetic methods.

[0193] Deuterium substituted compounds are synthesized using various methods such as described in: 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.

[0194] Deuterated starting materials are readily available and are subjected to the synthetic methods described herein to provide for the synthesis of deuterium-containing compounds.Large numbers of deuterium-containing reagents and building blocks are available commercially from chemical vendors, such as Aldrich Chemical Co.

[0195] Compounds of the present invention also include crystalline and amorphous forms of those compounds, pharmaceutically acceptable salts, and active metabolites of these compounds having the same type of activity, including, for example, polymorphs, pseudopolymorphs, solvates, hydrates, unsolvated polymorphs (including anhydrates), conformational polymorphs, and amorphous forms of the compounds, as well as mixtures thereof.

[0196] The compounds described herein may in some cases exist as diastereomers, enantiomers, or other stereoisomeric forms. Where absolute stereochemistry is not specified, the compounds presented herein include all diastereomeric. enantiomeric, and epimeric forms as well as the appropriate mixtures thereof. Separation of stereoisomers may be performed by chromatography or by forming diastereomers and separating 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, herein incorporated by reference for this disclosure). Stereoisomers may also be obtained by stereoselective synthesis.

[0197] The methods and compositions described herein include the use of amorphous forms as well as ciy stall ine forms (also known as polymorphs). The compounds described herein maybe in the form of pharmaceutically acceptable salts. As well, in some embodiments, active metabolites of these compounds having the same type of activity are included in the scope of the present disclosure. In addition, the compounds described herein can exist in unsolvated as well as solvated forms with pharmaceutically acceptable solvents such as water, ethanol, and the like. The solvated forms of the compounds presented herein are also considered to be disclosed herein.

[0198] In certain embodiments, compounds or salts of the compounds may be prodrugs, e.g., wherein a hydroxyl in the parent compound is presented as an ester or a carbonate, or carboxylic acid present in the parent compound is presented as an ester. The term “prodrug’’ is intended toencompass compounds which, under physiologic conditions, are converted into pharmaceutical agents of the present disclosure. One method for making a prodrug is to include one or more selected moieties which are hydrolyzed under physiologic conditions to reveal the desired molecule. In other embodiments, the prodrug is converted by an enzymatic activity of the host animal such as specific target cells in the host animal. For example, esters or carbonates (e.g., esters or carbonates of alcohols or carboxylic acids and esters of phosphonic acids) are preferred prodrugs of the present disclosure.

[0199] Prodrug forms of the herein described compounds, wherein the prodrug is metabolized in vivo to produce a compound as set forth herein are included within the scope of the claims. In some cases, some of the herein-described compounds may be a prodrug for another derivative or active compound.

[0200] Prodrugs are often useful because, in some situations, they may be easier to administer than the parent drug. They may, for instance, be bioavailable by oral administration whereas the parent is not. Prodrugs may help enhance the cell permeability of a compound relative to the parent drug. The prodrug may also have improved solubility in pharmaceutical compositions over the parent drug. Prodrugs may be designed as reversible drug derivatives, for use as modifiers to enhance drug transport to site-specific tissues or to increase drug residence inside of a cell.

[0201] In some embodiments, the design of a prodrug increases the lipophilicity of the pharmaceutical agent. In some embodiments, the design of a prodrug increases the effective water solubility. See, e.g., Fedorak et al., Am. J. Physiol., 269:G210-218 (1995); McLoed etal., 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)1 J. Larsen et al., Int. J.Pharmaceutics, 47, 103 (1988); Sinkula et a / ., 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 incorporated herein for such disclosure). According to another embodiment, the present disclosure provides methods of producing the above-defined compounds. The compounds may be synthesized using conventional techniques.Advantageously, these compounds are conveniently synthesized from readily available starting materials.

[0202] Synthetic chemistry transformations and methodologies useful in synthesizing the compounds described herein are known in the art and include, 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).Targeting Unit (L)

[0203] In some embodiments, for a Drug-Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I- A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the Targeting Unit is selected from an antibody or an antigen-binding fragment thereof. In some cases, the Targeting Unit is selected from a group consisting of chimeric antibodies, humanized antibodies, and human antibodies. In some cases, the Targeting Unit, performs a targeting function. In some cases, a Targeting unit specifically binds to a target molecule. In some cases, specifically binds refers to the ability of a Targeting unit (e.g., an antibody or portion thereol) described herein to bind to a target with a KD 10"5M (10000 nM) or less, e.g., 10'6M, 10'7M, 10’8M, 10'9M, 10'10M, 10'11M, 10'12M, or less. In some cases, a Targeting unit is said to specifically bind to its target when it preferentially recognizes its target in a complex mixture of proteins and / or macromolecules. In some cases, the antibody is a monoclonal antibody. In some cases, the antibody is UC-961. In some cases, the Targeting unit is PTK7. In some cases, L is PTK7. In some cases, the antibody is PTK7. In some cases, the antibody is ROR2.

[0204] In some embodiments, the Targeting unit is an antibody or antigen binding portion thereof is a bispecific or multispecific binding agent. Bispecific and multi-specific antibodies include the following: an scFvl-ScFv2, an ScFvl 2-Fc-scFv2 2, an IgG-scFv, a DVD-Ig, a triomab / quadroma, a two-in-one IgG, a scFv2-Fc, a TandAb, and an scFv-HSA-scFv. In some embodiments, an IgG-scFv is an IgG (H) -scFv, scFv-(H) IgG, IgG (L) -scFv, svFc- (L) IgG, 2scFV-IgG or IgG-2scFv.

[0205] In some embodiments, the Targeting unit is a cancer associated antigen such as CD19, CD20, CD30, CD33, CD38, CA125, MUC-1, prostate-specific membrane antigen (PSMA), CD44 surface adhesion molecule, mesothelin (MLSN), carcinoembryonic antigen (CEA), epidermal growth factor receptor (EGFR). EGFRvIII. vascular endothelial growth factor receptor-2 (VEGFR2) , high molecular weight-melanoma associated antigen (HMW-MAA) , MAGE-A1, IL-13R-a2, GD2, lp!9q, ABL1, AKT1, ALK, APC, AR, ATM, BRAF, BRCA1, BRCA2, cKIT, cMET, CSF1R, CTNNB1, FGFR1, FGFR2. FLT3, GNA11, GNAQ, GNAS, HRAS. IDH1, IDH2, JAK2, KDR (VEGFR2) , KRAS, MGMT, MGMT-Me. MLH1, MPL, NOTCH1, NRAS, PDGFRA, Pgp, PIK3CA, PR, PTEN, RET, RRM1, SMO, SPARC, TLE3, TOP2A, TOPO1, TP53, TS, TUBB3, VHL, CDH1, ERBB4, FBXW7, HNF1A, JAK3, NPM1, PTPN11, RBI, SMAD4, SMARCB1, STK1, MLH1, MSH2, MSH6, PMS2, ROS1, ERCC1, 5T4 (TPBG) , B7-H3, CCR7, CD105, CD22, CD46, CD47, CD56, CD70, CD71, CD79b,CDH6, CLDN6, CLDN18.2, CLEC12A, DLL3, DR5, ERBB3 (HER3) , EPCAM, F0LR1, IGF1R, IL2RA (CD25) , IL3RA, ITGB6, LIV-1, LRRC15, mesothelin (MSLN) , NaPi2b (SLC34A2) , nectin-4, PTK7, R0R1, SEZ6, SLC44A4, SLITRK6, Tissue Factor (TF) , TROP2 or B7-H4.

[0206] In some embodiments, a Targeting unit specifically binds to a target such as CD 19.CD20, CD30, CD33, CD70, LIV-1 or EGFRv3.

[0207] In some embodiments, for a Drug-Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I- A), (each of which further comprises a targeting unit) or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l). the Targeting unit is an antibody or antigen binding fragment thereof. In some cases, the antibody is a PTK.7 antibody. In some cases, the PTK7 antibody selected from Table 7, or antigen binding portion thereof.

[0208] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX),Formula (A), or Formula (A-l), L of the disclosed antibody-drug conjugate can be any PTK.7- binding antibody. In some cases, the antibody is a chimeric, CDR-grafted, humanized, or a recombinant human antibody, or PTK7-binding fragment thereof. In some cases, the antibody is an internalizing antibody and / or a neutralizing antibody. In some cases, the PTK7 antibody, or antigen-binding fragment thereof, includes one or more CDR(s) of the antibody (such as one, two, three, four, five, or all six CDRs). In some cases, the CDRs are as described elsewhere herein.

[0209] In some embodiments, a human PTK7 polypeptide sequence is available underUniProt Accession No. Q13308 (PTK7_HUMAN) and is shown below:MGAARGSPAR PRRLPLLSVL LLPLLGGTQT AIVFIKQPSS QDALQGRRAL LRCEVEAPGP VHVYWLLDGA PVQDTERRFA QGSSLSFAAV DRLQDSGTFQ CVARDDVTGE EARSANASFN IKWIEAGPW LKHPASEAEI QPQTQVTLRC HIDGHPRPTY QWFRDGTPLS DGQSNHTVSS KERNLTLRPA GPEHSGLYSC CAHSAFGQAC SSQNFTLS IA DESFARWLA PQDVWARYE EAMFHCQFSA QPPPSLQWLF EDETPITNRS RPPHLRRATV FANGSLLLTQ VRPRNAGIYR CIGQGQRGPP I ILEATLHLA EIEDMPLFEP RVFTAGSEER VTCLPPKGLP EPSVWWEHAG VRLPTHGRVY QKGHELVLAN IAESDAGVYT CHAANLAGQR RQDVNITVAT VPSWLKKPQD SQLEEGKPGY LDCLTQATPK PTWWYRNQM LI SEDSRFEV FKNGTLRINS VEVYDGTWYR CMSSTPAGSI EAQARVQVLE KLKFTPPPQP QQCMEFDKEA TVPCSATGRE KPTIKWERAD GSSLPEWVTD NAGTLHFARV TRDDAGNYTC IASNGPQGQI RAHVQLTVAV FITFKVEPER TTVYQGHTAL LQCEAQGDPK PLIQWKGKDR ILDPTKLGPR MHI FQNGSLV IHDVAPEDSG RYTCIAGNSC NIKHTEAPLY WDKPVPEES EGPGSPPPYK MIQTIGLSVG AAVAYI IAVL GLMFYCKKRC KAKRLQKQPE GEEPEMECLN GGPLQNGQPS AEIQEEVALT SLGSGPAATN KRHSTSDKMH FPRSSLQPIT TLGKSEFGEV FLAKAQGLEE GVAETLVLVK SLQSKDEQQQ LDFRRELEMF GKLNHANWR LLGLCREAEP HYMVLEYVDL GDLKQFLRIS KSKDEKLKSQ PLSTKQKVAL CTQVALGMEH LSNNRFVHKD LAARNCLVSA QRQVKVSALG LSKDVYNSEY YHFRQAWVPL RWMSPEAILE GDFSTKSDVW AFGVLMWEVF THGEMPHGGQ ADDEVLADLQ AGKARLPQPE GCPSKLYRLM QRCWALSPKDRPSFSEIASA LGDSTVDSKP ( SEQ ID NO : 198 )In the above sequence, amino acids 1-30 correspond to the signal sequence; amino acids 31-704 correspond to the extracellular domain (ECD); amino acids 705-725 correspond to the transmembrane domain; and amino acids 726-1070 correspond to the intracellular domain. The PTK7 binders of the conjugates described herein bind to the ECD of PTK7.

[0210] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the conjugate is conjugated to an anti-PTK.7 antibody or an antigen-binding portion thereof that competes or cross-competes for binding to human PTK7 with, or binds to the same epitope of human PTK7 as, any one of SLX-1040, Z12, Z23, Z31, SLX-1042, or SLX-1059.

[0211] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the conjugate is conjugated to an anti-PTK.7 antibody or an antigen-binding portion thereof that competes or cross-competes for binding to human PTK7 with, or binds to the same epitope of human PTK7 as, an antibody comprising: a) a heavy chain variable region (VH) comprising the amino acid sequence of SEQ ID NO:76 and a light chain variable region (VL) comprising the amino acid sequence of SEQ ID NO:75; b) a VH comprising the amino acid sequence of SEQ ID NO: 178 and a VL comprising the amino acid sequence of SEQ ID NO: 188; c) a VH comprising the amino acid sequence of SEQ ID NO: 193 and a VL comprising the amino acid sequence of SEQ ID NO: 188; d) a VH comprising the amino acid sequence of SEQ ID NO: 173 and a VL comprising the amino acid sequence of SEQ ID NO: 188; e) a VH comprising the amino acid sequence of SEQ ID NO: 112 and a VL comprising the amino acid sequence of SEQ ID NO: 111 ; orI) a VH comprising the amino acid sequence of SEQ ID NO: 128 and a VL comprising the amino acid sequence of SEQ ID NO: 127.

[0212] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the anti-PTK.7 antibody or antigen-binding portion comprises the HCDR1-3 and LCDR1-3 amino acid sequences of any one of the antibodies exemplified herein. The assignment of CDR regions may be in accordance with any method know n in the art, such as IMGT®, Kabat, Chothia, Martin, Contact, or AHo definitions, or any combination of any of these definitions (Kabat plus Chothia, for example). Examples of CDR definitions under different methods are shown below for SLX-1040 (SEQ: SEQ ID NO):SLX-1040 HCDRsSLX-1040 LCDRsThus, for example, the SLX-1040 IMGT®-defined HCDR1-3 and LCDR1-3 sequences of SEQ ID NOs: 151, 157, 161, 164, 167, and 170, respectively, may be replaced in any embodiment described herein bySEQ ID NOs: 149, 155, 160. 163, 166. and 170, respectively;SEQ ID NOs: 150, 156, 160, 163, 166, and 170, respectively;SEQ ID NOs: 152, 158, 161, 163, 168, and 170, respectively; orSEQ ID NOs: 153, 159, 162, 165, 169, and 171, respectively.Also contemplated is a set of SLX-1040 CDRs wherein each of HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 may individually be specified according to any of the methods for defining SLX-1040 CDRs as shown above (e.g., HCDR1 specified by the Kabat definition, HCDR2 specified by the Chothia definition, etc ). The same means for defining SLX-1040 CDRs are contemplated for any of the exemplified antibodies herein.

[0213] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX).Formula (A), or Formula (A-l ), the anti-PTK7 antibody or antigen-binding portion thereof has:- an HCDR1 selected from SEQ ID NOs: 149-154;- an HCDR2 selected from SEQ ID NOs: 155-159;- an HCDR3 selected from SEQ ID NOs: 160-162;- an LCDR1 selected from SEQ ID NOs: 163-165;- an LCDR2 selected from SEQ ID NOs: 166-169; and- an LCDR3 selected from SEQ ID NOs: 170 and 171.

[0214] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l ), the anti-PTK7 antibody or antigen-binding portion thereof has HCDR1-3 and LCDRl-3 comprising SEQ ID NOs: 151. 157, 161, 164, 167, and 170, respectively. In some embodiments, the anti-PTK7 antibody or antigen-binding portion has HCDR1-3 and LCDRl-3 comprising SEQ ID NOs: 154, 155, 161, 163, 166, and 170, respectively.

[0215] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the anti-PTK7 antibody or antigen-binding portion has HCDR1- 3 and LCDR1-3 comprising SEQ ID NOs:204, 209, 213, 216, 219, and 222, respectively.

[0216] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the anti-PTK7 antibody or antigen-binding portion has HCDR1- 3 and LCDR1-3 comprising SEQ ID NOs:226, 231, 235, 238, 241, and 244, respectively.

[0217] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX). Formula (A), or Formula (A-l), the anti-PTK7 antibody comprises an HC amino acid sequence comprising SEQ ID NOs:76 and 201, optionally without the C-terminal lysine, and an LC amino acid sequence comprising SEQ ID NOs:75 and 199.

[0218] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the anti-PTK7 antibody comprises an HC amino acid sequence comprising SEQ ID NOs: 178 and 201, optionally without the C-terminal lysine, and an LC amino acid sequence comprising SEQ ID NOs: 188 and 199.

[0219] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the anti-PTK7 antibody comprises an HC amino acid sequence comprising SEQ ID NOs: 193 and 201, optionally without the C-terminal lysine, and an LC amino acid sequence comprising SEQ ID NOs: 188 and 199.

[0220] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the anti-PTK7 antibody comprises an HC amino acid sequence comprising SEQ ID NOs: 173 and 201, optionally without the C-terminal lysine, and an LC amino acid sequence comprising SEQ ID NOs: 188 and 199.

[0221] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the anti-PTK7 antibody comprises an HC amino acid sequence comprising SEQ ID NOs: 1 12 and 201, optionally without the C-terminal lysine, and an LC amino acid sequence comprising SEQ ID NOs: 111 and 199.

[0222] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the anti-PTK7 antibody comprises an HC amino acid sequencecomprising SEQ ID NOs: 128 and 201, optionally without the C-terminal lysine, and an LC amino acid sequence comprising SEQ ID NOs: 127 and 199.

[0223] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l ), the anti-PTK7 antibody of the present disclosure can be an IgG, an IgM, an IgE, an IgA, or an IgD molecule, but is typically of the IgG isotype, e.g., of IgG subclass IgGl, IgG2, IgG3 or IgG4. In some embodiments, the antibody is of the isotype subclass IgGl.

[0224] In some embodiments, for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), the Targeting unit includes a cysteine. In some cases, the Targeting unit includes a glutamine.Making of PTK7-Binding Proteins (e.g., anti-PTK7 antibodies and proteins comprising the antibodies or antigen-binding portions thereof)

[0225] The PTK7-binding protein of the present disclosure may be produced recombinantly using isolated nucleic acid molecules such as expression constructs. The coding sequences for each polypeptide chain may be cloned into a single vector or cloned into separate vectors (e.g., a pair or set of vectors). The proteins may be produced in host cells, e.g., mammalian host cells, using appropriate expression constructs. Mammalian cell lines available as hosts for expression include, without limitation, Chinese hamster ovary (CHO) cells, NSO cells. SP2 cells, HEK- 293T cells, 293 Freestyle cells (Invitrogen), NIH-3T3 cells, HeLa cells, baby hamster kidney (BHK) cells, African green monkey kidney cells (COS), human hepatocellular carcinoma cells (e.g., Hep G2), and A549 cells. Other cell lines that may be used are insect cell lines, such as Sf9 or Sf21 cells, and yeast cell lines. In certain embodiments, the cell lines are not derived from a human embryo. Cell lines may be selected based on their expression levels.

[0226] Host cells used to produce the PTK7-binding proteins are '‘recombinant host cells.” A “recombinant host cell” (or simply “host cell”), as used herein, means a cell into which a recombinant expression construct has been introduced. By definition, a recombinant host cell does not occur in nature. A protein produced from a recombinant host cell is a recombinant protein.

[0227] The PTK7-binding protein may be isolated and purified from the host cell culture using well known methods, such as centrifugation; ultracentrifugation; protein A, protein G, protein A / G, or protein L purification; and / or ion exchange chromatography.Pharmaceutical Formulations / Compositions

[0228] Provided herein, in certain embodiments, are compositions comprising a therapeutically effective amount of a Drug-Linker or salt of Formula (X), Formula (I), orFormula (I-A), or for a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l) (also referred to herein as “a pharmaceutical agent”).

[0229] Pharmaceutical compositions may be formulated using one or more physiologically acceptable carriers including excipients and auxiliaries which facilitate processing of the pharmaceutical agent into preparations which are used pharmaceutically. Proper formulation is dependent upon the route of administration chosen. A summary of pharmaceutical compositions is found, for example, in Remington: The Science and Practice of Pharmacy, Nineteenth Ed (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, Seventh Ed. (Lippincott Williams & Wilkins, 1999).

[0230] The compositions and methods of the present disclosure may be utilized to treat an individual in need thereof. In certain embodiments, the individual is a mammal such as a human, or a non-human mammal. When administered to an animal, such as a human, the composition or the pharmaceutical agent, is preferably administered as a pharmaceutical composition comprising, for example, a pharmaceutical agent 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 physiologically buffered saline or other solvents or vehicles such as glycols, glycerol, oils such as olive oil, or injectable organic esters. In a preferred embodiment, when such pharmaceutical compositions are for human administration, particularly for invasive routes of administration, e.g.. routes, such as injection or implantation, that circumvent transport or diffusion through an epithelial barrier, the aqueous solution is pyrogen-free, or substantially pyrogen-free. The excipients can be chosen, for example, to effect delayed release of an agent or to selectively target one or more cells, tissues or organs. The pharmaceutical composition can be in dosage unit form such as tablet, capsule, granule, lyophile for reconstitution, powder, solution, syrup, suppository, injection or the like. The composition can also be present in a transdermal delivery system, e g., a skin patch. The composition can also be present in a solution suitable for topical administration, such as an eye drop.

[0231] A pharmaceutically acceptable excipient can contain physiologically acceptable agents that act, for example, to stabilize, increase solubility or to increase the absorption of a compound such as a pharmaceutical agent. Such physiologically acceptable agents include, for example, carbohydrates, such as glucose, sucrose or dextrans, antioxidants, such as ascorbic acid or glutathione, chelating agents, low molecular weight proteins or other stabilizers or excipients. The choice of a pharmaceutically acceptable excipient, including a physiologically acceptableagent, depends, for example, on the route of administration of the composition. The preparation or pharmaceutical composition can be a self emulsifying drug delivery system or a self microemulsifying drug delivery7system. The pharmaceutical composition (preparation) also can be a liposome or other polymer matrix, which can have incorporated therein, for example, a compound of the invention. Liposomes, for example, which comprise phospholipids or other lipids, are nontoxic, physiologically acceptable and metabolizable carriers that are relatively simple to make and administer.

[0232] A pharmaceutical composition (preparation) can be administered to a subject by any of a number of routes of administration including, for example, orally, for example, drenches as in 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, e.g., sublingually; anally, rectally or vaginally, for example, as a pessary7, cream or foam; parenterally, including intramuscularly, intravenously, subcutaneously or intrathecally as. for example, a sterile solution or suspension; nasally; intraperitoneally; subcutaneously; transdermally, for example, as a patch applied to the skin; and topically, for example, as a cream, ointment or spray applied to the skin, or as an eye drop. The compound may also be formulated for inhalation. In certain embodiments, a compound may be simply dissolved or suspended in sterile water.

[0233] A pharmaceutical composition may be a sterile aqueous or non-aqueous solution, suspension or emulsion, e.g., a microemulsion. The excipients described herein are examples and are in no way limiting. An effective amount or therapeutically effective amount refers to an amount of the one or more pharmaceutical agents administered to a subject, either as a single dose or as part of a series of doses, which is effective to produce a desired therapeutic effect.

[0234] Subjects may generally be monitored for therapeutic effectiveness using assays and methods suitable for the condition being treated, which assays will be familiar to those having ordinary skill in the art and are described herein. Pharmacokinetics of a pharmaceutical agent, or one or more metabolites thereof, that is administered to a subject may be monitored by determining the level of the pharmaceutical agent or metabolite in a biological fluid, for example, in the blood, blood fraction, e.g., serum, and / or in the urine, and / or other biological sample or biological tissue from the subject. Any method practiced in the art and described herein to detect the agent may be used to measure the level of the pharmaceutical agent or metabolite during a treatment course.

[0235] The dose of a pharmaceutical agent described herein for treating a disease or disorder may depend upon the subject’s condition, that is, stage of the disease, severity of symptoms caused by the disease, general health status, as well as age, gender, and weight, and other factorsapparent to a person skilled in the medical art. Pharmaceutical compositions may be administered in a manner appropriate to the disease to be treated as determined by persons skilled in the medical arts. In addition to the factors described herein and above related to use of pharmaceutical agent for treating a disease or disorder, suitable duration and frequency of administration of the pharmaceutical agent may also be determined or adjusted by such factors as the condition of the patient, the type and severity of the patient’s disease, the particular form of the active ingredient, and the method of administration. Optimal doses of an agent may generally be determined using experimental models and / or clinical trials. The optimal dose may depend upon the body mass, weight, or blood volume of the subject. The use of the minimum dose that is sufficient to provide effective therapy is usually preferred. Design and execution of pre-clinical and clinical studies for a pharmaceutical agent, including when administered for prophylactic benefit, described herein are well within the skill of a person skilled in the relevant art. When two or more pharmaceutical agents are administered to treat a disease or disorder, the optimal dose of each pharmaceutical agent may be different, such as less than when either agent is administered alone as a single agent therapy. In certain particular embodiments, two pharmaceutical agents in combination may act synergistically or additively, and either agent may be used in a lesser amount than if administered alone. An amount of a pharmaceutical agent that may be administered per day may be, for example, between about 0.01 mg / kg and 100 mg / kg, e.g., between about 0.1 to 1 mg / kg, between about 1 to 10 mg / kg, between about 10-50 mg / kg, between about 50-100 mg / kg body weight. In other embodiments, the amount of a pharmaceutical agent that may be administered per day is between about 0.01 mg / kg and 1000 mg / kg, between about 100-500 mg / kg, or between about 500-1000 mg / kg body weight. The optimal dose, per day or per course of treatment, may be different for the disease or disorder to be treated and may also vary with the administrative route and therapeutic regimen.

[0236] Pharmaceutical compositions comprising a pharmaceutical agent can be formulated in a manner appropriate for the delivery method by using techniques routinely practiced in the art. The composition may be in the form of a solid, e.g.. tablet, capsule, semi-solid, e.g, gel, liquid, or gas, e g., aerosol. In other embodiments, the pharmaceutical composition is administered as a bolus infusion.

[0237] Pharmaceutical acceptable excipients are well known in the pharmaceutical art and described, for example, in Rowe et al.. Handbook of Pharmaceutical Excipients: A Comprehensive Guide to Uses, Properties, and Safety, 5thEd., 2006, and in Remington: The Science cind Practice of Pharmacy (Gennaro, 21stEd. Mack Pub. Co., Easton, PA (2005)). Exemplary pharmaceutically acceptable excipients include sterile saline and phosphate buffered saline at physiological pH. Preservatives, stabilizers, dyes, buffers, and the like may be providedin the pharmaceutical composition. In addition, antioxidants and suspending agents may also be used. In general, the type of excipient is selected based on the mode of administration, as well as the chemical composition of the active ingredient(s). Alternatively, compositions described herein may be formulated as a lyophilizate. A composition described herein may be lyophilized or otherwise formulated as a lyophilized product using one or more appropriate excipient solutions for solubilizing and / or diluting the pharmaceutical agent(s) of the composition upon administration. In other embodiments, the pharmaceutical agent may be encapsulated within liposomes using technology known and practiced in the art. In certain particular embodiments, a pharmaceutical agent is not formulated within liposomes for application to a stent that is used for treating highly, though not totally, occluded arteries. Pharmaceutical compositions may be formulated for any appropriate manner of administration described herein and in the art.

[0238] A pharmaceutical composition, e.g., for oral administration or for injection, infusion, subcutaneous delivery, intramuscular delivery, intraperitoneal delivery or other method, may be in the form of a liquid. A liquid pharmaceutical composition may include, for example, one or more of the following: a sterile diluent such as water, saline solution, preferably physiological saline, Ringer’s solution, isotonic sodium chloride, fixed oils that may sen e as the solvent or suspending medium, polyethylene glycols, glycerin, propylene glycol or other solvents; antibacterial agents; antioxidants; chelating agents; buffers and agents for the adjustment of tonicity' such as sodium chloride or dextrose. A parenteral composition can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic. The use of physiological saline is preferred, and an injectable pharmaceutical composition is preferably sterile. In another embodiment, for treatment of an ophthalmological condition or disease, a liquid pharmaceutical composition may be applied to the eye in the form of eye drops. A liquid pharmaceutical composition may be delivered orally.

[0239] For oral formulations, at least one of the pharmaceutical agents described herein can be used alone or in combination with appropriate additives to make tablets, powders, granules or capsules, and if desired, with diluents, buffering agents, moistening agents, preservatives, coloring agents, and flavoring agents. The pharmaceutical agents may be formulated with a buffering agent to provide for protection of the compound from low pH of the gastric environment and / or an enteric coating. A pharmaceutical agent included in a pharmaceutical composition may be formulated for oral delivery with a flavoring agent, e.g., in a liquid, solid or semi-solid formulation and / or with an enteric coating.

[0240] A pharmaceutical composition comprising any one of the pharmaceutical agents described herein may be formulated for sustained or slow release, also called timed release or controlled release. Such compositions may generally be prepared using well known technologyand administered by, for example, oral, rectal, intradermal, or subcutaneous implantation, or by implantation at the desired target site. Sustained-release formulations may contain the compound dispersed in a carrier matrix and / or contained within a reservoir surrounded by a rate controlling membrane. Excipients for use within such formulations are biocompatible, and may also be biodegradable; preferably the formulation provides a relatively constant level of active component release. The amount of pharmaceutical agent contained within a sustained release formulation depends upon the site of implantation, the rate and expected duration of release, and the nature of the condition, disease or disorder to be treated or prevented.

[0241] In certain embodiments, the pharmaceutical compositions comprising a pharmaceutical agent are formulated for transdermal, intradermal, or topical administration. The compositions can be administered using a syringe, bandage, transdermal patch, insert, or syringe-like applicator, as a powder / talc or other solid, liquid, spray, aerosol, ointment, foam, cream, gel, paste. This preferably is in the form of a controlled release formulation or sustained release formulation administered topically or injected directly into the skin adjacent to or within the area to be treated, e.g., intradermally or subcutaneously. The active compositions can also be delivered via iontophoresis. Preservatives can be used to prevent the grow th of fungi and other microorganisms. Suitable preservatives include, but are not limited to, benzoic acid, butylparaben, ethyl paraben, methyl paraben, propylparaben, sodium benzoate, sodium propionate, benzalkonium chloride, benzethonium chloride, benzyl alcohol, cetypyridinium chloride, chlorobutanol, phenol, phenylethyl alcohol, thimerosal, and combinations thereof.

[0242] Pharmaceutical compositions comprising a pharmaceutical agent can be formulated as emulsions for topical application. An emulsion contains one liquid distributed in the body of a second liquid. The emulsion may be an oil-in-water emulsion or a water-in-oil emulsion. Either or both of the oil phase and the aqueous phase may contain one or more surfactants, emulsifiers, emulsion stabilizers, buffers, and other excipients. The oil phase may contain other oily pharmaceutically approved excipients. Suitable surfactants include, but are not limited to, anionic surfactants, non-ionic surfactants, cationic surfactants, and amphoteric surfactants. Compositions for topical application may also include at least one suitable suspending agent, antioxidant, chelating agent, emollient, or humectant.

[0243] Ointments and creams may, for example, be formulated with an aqueous or oily base with the addition of suitable thickening and / or gelling agents. Lotions may be formulated with an aqueous or oily base and will in general also contain one or more emulsifying agents, stabilizing agents, dispersing agents, suspending agents, thickening agents, or coloring agents. Liquid sprays may be delivered from pressurized packs, for example, via a specially shapedclosure. Oil-in-water emulsions can also be used in the compositions, patches, bandages and articles. These systems are semisolid emulsions, micro-emulsions, or foam emulsion systems.

[0244] In some embodiments, the pharmaceutical agent described herein can be formulated as in inhalant. Inhaled methods can deliver medication directly to the airway. The pharmaceutical agent can be formulated as aerosols, microspheres, liposomes, or nanoparticles. The pharmaceutical agent can be formulated with solvents, gases, nitrates, or any combinations thereof. Compositions described herein are optionally formulated for deliver}' as a liquid aerosol or inhalable dry' powder. Liquid aerosol formulations are optionally nebulized predominantly into particle sizes that can be delivered to the terminal and respiratory bronchioles. Liquid aerosol and inhalable dry powder formulations are preferably delivered throughout the endobronchial tree to the terminal bronchioles and eventually' to the parenchymal tissue.

[0245] Aerosolized formulations described herein are optionally delivered using an aerosol forming device, such as ajet, vibrating porous plate or ultrasonic nebulizer, preferably selected to allow the formation of aerosol particles having with a mass medium average diameter predominantly between 1 to 5 p. Further, the formulation preferably has balanced osmolarity' ionic strength and chloride concentration, and the smallest aerosolizable volume able to deliver effective dose of the pharmaceutical agent. Additionally, the aerosolized formulation preferably does not impair negatively the functionality of the airways and does not cause undesirable side effects.

[0246] Aerosolization devices suitable for administration of aerosol formulations described herein include, for example, jet, vibrating porous plate, ultrasonic nebulizers and energized dry powder inhalers, that are able to nebulize the formulation into aerosol particle size predominantly in the size range from 1-5 p. Predominantly in this application means that at least 70% but preferably more than 90% of all generated aerosol particles are within 1-5 p range. A jet nebulizer works by air pressure to break a liquid solution into aerosol droplets. Vibrating porous plate nebulizers work by using a sonic vacuum produced by a rapidly vibrating porous plate to extrude a solvent droplet through a porous plate. An ultrasonic nebulizer works by a piezoelectric crystal that shears a liquid into small aerosol droplets. A variety of suitable devices are available, including, for example, AeroNebTM and AeroDoseTM vibrating porous plate nebulizers (AeroGen, Inc., Sunnyvale, California), Sidestream® nebulizers (Medic-Aid Ltd., West Sussex. England), Pari LC® and Pari LC Star® jet nebulizers (Pari Respiratory- Equipment, Inc.. Richmond. Virginia), and AerosonicTM (DeVilbiss Medizinische Produkte (Deutschland) GmbH, Heiden, Germany ) and UltraAire® (Omron Healthcare, Inc., Vernon Hills, Illinois) ultrasonic nebulizers.

[0247] In some embodiments, the pharmaceutical agent(s) can be formulated with oleaginous bases or ointments to form a semisolid composition with a desired shape. In addition to the pharmaceutical agent, these semisolid compositions can contain dissolved and / or suspended bactericidal agents, preservatives and / or a buffer system. A petrolatum component that may be included may be any paraffin ranging in viscosity from mineral oil that incorporates isobutylene, colloidal silica, or stearate salts to paraffin waxes. Absorption bases can be used with an oleaginous system. Additives may include cholesterol, lanolin (lanolin derivatives, beeswax, fatty alcohols, wool wax alcohols, low' HLB (hydrophobellipophobe balance) emulsifiers, and assorted ionic and nonionic surfactants, singularly or in combination.

[0248] Controlled or sustained release transdermal or topical formulations can be achieved by the addition of time-release additives, such as polymeric structures, matrices, that are available in the art. For example, the compositions may be administered through use of hot-melt extrusion articles, such as bioadhesive hot-melt extruded film. The formulation can comprise a cross-linked poly carboxylic acid polymer formulation. A cross-linking agent may be present in an amount that provides adequate adhesion to allow' the system to remain attached to target epithelial or endothelial cell surfaces for a sufficient time to allow' the desired release of the compound.

[0249] An insert, transdermal patch, bandage or article can comprise a mixture or coating of polymers that provide release of the pharmaceutical agents at a constant rate over a prolonged period of time. In some embodiments, the article, transdermal patch or insert comprises water- soluble pore forming agents, such as polyethylene glycol (PEG) that can be mixed with water insoluble polymers to increase the durability of the insert and to prolong the release of the active ingredients.

[0250] Transdermal devices (inserts, patches, bandages) may also comprise a water insoluble polymer. Rate controlling polymers may be useful for administration to sites where pH change can be used to effect release. These rate controlling polymers can be applied using a continuous coating film during the process of spraying and drying with the active compound. In one embodiment, the coating formulation is used to coat pellets comprising the active ingredients that are compressed to form a solid, biodegradable insert.

[0251] A polymer formulation can also be utilized to provide controlled or sustained release. Bioadhesive polymers described in the art may be used. By way of example, a sustained-release gel and the compound may be incorporated in a polymeric matrix, such as a hydrophobic polymer matrix. Examples of a polymeric matrix include a microparticle. The microparticles can be microspheres, and the core may be of a different material than the polymeric shell. Alternatively, the polymer may be cast as a thin slab or film, a powder produced by grinding orother standard techniques, or a gel such as a hydrogel. 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 delivery of the pharmaceutical agent. The matrices can be formed by solvent evaporation, spray drying, solvent extraction and other methods known to those skilled in the art.

[0252] Kits with unit doses of one or more of the agents described herein, usually in oral or injectable doses, are provided. Such kits may include a container containing the unit dose, an informational package insert describing the use and attendant benefits of the drugs in treating disease, and optionally an appliance or device for delivery of the composition.Methods of Treatment

[0253] In an aspect, the present disclosure provides a method of treating a subject with a cancer. In some cases, the treatment of a subject with a cancer includes administering to a subject in need thereof a Drug-Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I -A), or a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), or a pharmaceutical composition of any one thereof.

[0254] In an aspect, the present disclosure provides a method of treating a subject with a tumor. In some cases, the treatment of a subject with the tumor includes administering to a subject in need thereof a Drug-Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A). or a conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), or a pharmaceutical composition of any one thereof. In some cases, the tumor is associated with a cancer. In some cases, the cancer is selected from the group consisting of lung cancer, kidney cancer, urethral cancer, colorectal cancer, prostate cancer, glioblastoma multiforme, ovarian cancer, pancreatic, breast, melanoma, liver, bladder, stomach, and esophageal cancers.

[0255] In some embodiments, conjugates described herein are useful for inhibiting the multiplication of a tumor cell or cancer cell, causing apoptosis in a tumor or cancer cell, or for treating cancer in a patient.

[0256] The conjugates provide conjugation-specific tumor or cancer targeting, thus reducing general toxicity' of these compounds. The linker stabilizes the conjugates in blood, yet is cleavable by enzymes within the cell (e.g., lysosomal enzymes), liberating the Drug(s) (e.g., exatecan).

[0257] In some embodiments, conjugates described herein can be used for treating diseases 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', orophary nx, lary nx, hypophary nx, salivary' glands, and paragangliomas; cancers of the liver and biliary tree, particularly hepatocellular carcinoma; intestinal cancers, particularlycolorectal cancer; ovarian cancer; small cell and non-small cell lung cancer (SCLC and NSCLC); breast cancer sarcomas, such as fibrosarcoma, malignant fibrous histiocytoma, embryonal rhabdomyosarcoma, leiomysosarcoma, neurofibrosarcoma, osteosarcoma, synovial sarcoma, liposarcoma, and alveolar soft part sarcoma; leukemias such as acute promyelocytic leukemia (APL). acute myelogenous leukemia (AML), acute lymphoblastic leukemia (ALL), and chronic myelogenous leukemia (CML); neoplasms of the central nervous systems, particularly brain cancer; multiple myeloma (MM), lymphomas such as Hodgkin's lymphoma, lymphoplasmacytoid lymphoma, follicular lymphoma, mucosa-associated lymphoid tissue lymphoma, mantle cell lymphoma, B-lineage large cell lymphoma, Burkitt's lymphoma, and T- cell anaplastic large cell lymphoma. Clinically, practice of the methods and use of compositions described herein will result in a reduction in the size or number of the cancerous growth and / or a reduction in associated symptoms (where applicable). Pathologically, practice of the method and use of 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. The method of treating such diseases comprises administering a therapeutically effective amount of an inventive combination to a subject. The method may be repeated as necessary . The cancer can be renal, lung, gastric, or ovarian cancer.

[0258] In some embodiments, the conjugates of the present disclosure are used to treat cancer in a patient (e.g., a mammal such as a human) in need thereof. In certain embodiments, the cancer is a PTK7-expressing cancer. The ADC may be administered alone or in combination with other therapeutic agents.

[0259] In some embodiments, the treatment of tumor-bearing subjects inhibits tumor growth by at least about 20%, more preferably by at least about 40%, even more preferably by at least about 60%, and still more preferably by at least about 80% relative to untreated subjects. A therapeutically effective amount of a therapeutic compound can decrease tumor size, or otherwise ameliorate symptoms in a subject, which is typically a human but can be another mammal.

[0260] In some embodiments, compositions described herein can be administered in combination with other therapeutic agents, including antibodies, alkylating agents, angiogenesis inhibitors, antimetabolites. DNA cleavers. DNA crosslinkers, DNA intercalators. 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, ty rosine kinase inhibitors, and serine / threonine kinase inhibitors. Specific therapeutic agents includeadalimumab, ansamitocin P3, auristatin, bendamustine, bevacizumab, bicalutamide, bleomycin, bortezomib, busulfan, callistatin A, camptothecin, capecitabine, carboplatin, carmustine, cetuximab, cisplatin, cladribin, cytarabin, cryptophycins, dacarbazine, dasatinib, daunorubicin, docetaxel, doxorubicin, duocarmycin, dynemycin A, epothilones, etoposide, floxuridine, fludarabine, 5 -fluorouracil, gefitinib, gemcitabine, ipilimumab, hydroxyurea, imatinib. infliximab, interferons, interleukins, (B-lapachone, lenalidomide, irinotecan, maytansine, mechlorethamine, melphalan, 6-mercaptopurine, methotrexate, mitomycin C, nilotinib, oxaliplatin, paclitaxel, procarbazine, suberoylanilide hydroxamic acid (SAHA), 6-thioguanidine, thiotepa, teniposide, topotecan, trastuzumab, trichostatin A. vinblastine, vincristine, and vindesine.

[0261] The Drug-Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A), or the conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), can be used in the preparation of medicaments for the prevention or treatment of diseases or conditions. In addition, a method for treating any of the diseases or conditions described herein in a subject in need of such treatment, involves administration of pharmaceutical compositions containing at least one compound described herein, or a pharmaceutically acceptable salt, pharmaceutically acceptable prodrug, or pharmaceutically acceptable solvate thereof, in therapeutically effective amounts to said subject.

[0262] The Drug-Linker or salt of Formula (B), Formula (X), Formula (I), or Formula (I-A), or the conjugate or salt of Formula (C), Formula (XX), Formula (A), or Formula (A-l), described herein can be administered for prophylactic and / or therapeutic treatments. In therapeutic applications, the compositions are administered to a patient already suffering from a disease or condition, in an amount sufficient to cure or at least partially arrest the symptoms of the disease or condition. Amounts effective for this use will depend on the severity and course of the disease or condition, previous therapy, the patient's health status, weight, and response to the drugs, and the judgment of the treating physician.

[0263] In prophylactic applications, compositions containing the compounds described herein are administered to a patient susceptible to or otherw ise at risk of a particular disease, disorder or condition. Such an amount is defined to be a " prophy tactically effective amount or dose." In this use, the precise amounts also depend on the patient's state of health, weight, and the like. When used in a patient, effective amounts for this use will depend on the severity and course of the disease, disorder or condition, previous therapy, the patient's health status and response to the drugs, and the judgment of the treating physician.

[0264] In the case wherein the patient's condition does not improve, upon the doctor’s discretion the administration of the compounds may be administered chronically, that is, for anextended period of time, including throughout the duration of the patient’s life in order to ameliorate or otherw ise control or limit the symptoms of the patient’s disease or condition.

[0265] Once improvement of the patient's conditions has occurred, a maintenance dose is administered if necessary. Subsequently, the dosage or the frequency of administration, or both, can be reduced, as a function of the symptoms, to a level at which the improved disease, disorder or condition is retained. Patients can, however, require intermittent treatment on a longterm basis upon any recurrence of symptoms.

[0266] The amount of a given agent that will correspond to such an amount will vary depending upon factors such as the particular compound, disease or condition and its severity, the identity (e.g., weight) of the subject or host in need of treatment, but can nevertheless be determined in a manner recognized in the field according to the particular circumstances surrounding the case, including, e.g., the specific agent being administered, the route of administration, the condition being treated, and the subject or host being treated. In general, however, doses employed for adult human treatment will typically be in the range of about 0.02 - about 5000 mg per day, in some embodiments, about 1 - about 1500 mg per day. The desired dose may conveniently be presented in a single dose or as divided doses administered simultaneously (or over a short period of time) or at appropriate intervals, for example as two, three, four or more sub-doses per day.

[0267] The pharmaceutical composition described herein may be in unit dosage forms suitable for single administration of precise dosages. In unit dosage form, the formulation is divided into unit doses containing appropriate quantities of one or more compound. The unit dosage may be in the form of a package containing discrete quantities of the formulation. Nonlimiting examples are packaged tablets or capsules, and powders in vials or ampoules. Aqueous suspension compositions can be packaged in single-dose non-reclosable containers. Alternatively, multiple-dose reclosable containers can be used, in which case it is typical to include a preservative in the composition. By way of example only, formulations for parenteral injection may be presented in unit dosage form, which include, but are not limited to ampoules, or in multi -dose containers, with an added preservative.

[0268] Toxicity and therapeutic efficacy of such therapeutic regimens can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, including, but not limited to, the determination of the LD50 (the dose lethal to 50% of the population) and the ED50 (the dose therapeutically effective in 50% of the population). The dose ratio betw een the toxic and therapeutic effects is the therapeutic index and it can be expressed as the ratio between LD50 and ED50. Compounds exhibiting high therapeutic indices are preferred. The data obtained from cell culture assays and animal studies can be used in formulating a range of dosage for use inhuman. The dosage of such compounds lies preferably within a range of circulating concentrations that include the ED50 with minimal toxicity. The dosage may vary within this range depending upon the dosage form employed and the route of administration utilized.

[0269] In certain embodiments, the invention provides a method of treating or preventing a disease, state, or condition in a patient in need thereof comprising administering to the patient an effective amount of a compound of any one of embodiments of the invention or a pharmaceutically acceptable salt thereof. The disease, state or condition may be selected from a group as described elsewhere herein.Preparation of Drug-Linkers and Conjugates of the Disclosure

[0270] The Linkers, Drug-Linkers and conjugates of the present disclosure can generally be prepared in a number of ways well known to those skilled in the art of organic synthesis.

[0271] In some embodiments, Linkers, Drug-Linkers and conjugates of the present disclosure can be synthesized using the methods described herein, together with synthetic methods known in the art of synthetic organic chemistry, or variations thereof as appreciated by those skilled in the art. In some embodiments, a conjugate may be prepared by several routes employing organic chemistry reactions, conditions, and reagents known to those skilled in the art, including: (1) reaction of a nucleophilic group of a Targeting unit (e.g., an antibody or antigen binding portion thereof or non-antibody protein scaffold) with a bivalent Linker to form a Targeting unit-Linker intermediate via a covalent bond, followed by reaction with a Drug; and (2) reaction of a nucleophilic group of a Drug with a bivalent Linker, to form Drug-Linker, via a covalent bond, followed by reaction with a nucleophilic group of a Targeting unit.

[0272] In some embodiments, techniques for attaching a drug to Targeting units (such as antibodies or antigen binding portions thereof or non-antibody scaffolds) via linkers may be used. In some cases, a Linker is first attached to a Drug (e.g., a cytotoxic agent (s), immune modulatory' agent or other agent) and then the Drug-Linker (s) is attached to the Targeting unit (e.g., an antibody or antigen binding portion thereof or non-antibody protein scaffold). In some cases, a Linker is first attached to a Targeting unit (e.g.. an antibody or antigen binding portion thereof or non-antibody protein scaffold), and then a Drug is attached to a Linker.

[0273] In some embodiments, a Drug is attached to a Targeting unit via a Linker in a manner that reduces the activity' of the Drug until it is released from the conjugate (e.g., by hydrolysis, by proteolytic degradation or by a cleaving agent.

[0274] In some embodiments, nucleophilic groups on Targeting units such as antibodies, antigen binding portions and other binding agents (including non-antibody scaffolds) include, but are not limited to: (i) N-terminal amine groups, (ii) side chain amine groups, e.g. lysine, (iii) side chain thiol groups, e.g. cysteine, and (iv) sugar hydroxyl or amino groups where theantibody is glycosylated. Amine, thiol, and hydroxyl groups are nucleophilic and capable of reacting to form covalent bonds with electrophilic groups on Linkers including: (i) active esters such as NHS esters, HOBt esters, haloformates, and acid halides; (ii) alky l and benzy l halides such as haloacetamides; and (iii) aldehydes, ketones, carboxyl, and maleimide groups. In some cases, Targeting units, such as antibodies (and antigen binding portions and other binding agents (including non-antibody scaffolds)) have reducible interchain disulfides, i.e., cysteine bridges. In some cases, antibodies (and antigen binding portions and other binding agents (including nonantibody scaffolds)) may be made reactive for conjugation with Linkers or Drug-Linkers bytreatment with a reducing agent such as DTT (dithiothreitol) or tri carbonylethylphosphine (TCEP), such that the antibody is fully or partially reduced. In some cases, each cysteine bridge will thus form, theoretically, two reactive thiol nucleophiles. In some cases, additional nucleophilic groups can be introduced into Targeting units such as antibodies (and antigen binding portions and other binding agents (including non-antibody scaffolds)) through modification of lysine residues, e.g.. by reacting lysine residues with 2 -iminothiolane (Traut's reagent), resulting in conversion of an amine into a thiol. In some cases, reactive thiol groups may also be introduced into a Targeting unit (such as an antibody and antigen binding portions and other binding agents (including non-antibody scaffolds)) by introducing one, two, three, four, or more cysteine residues (e.g.. by preparing antibodies, antigen binding portions and other binding agents (including non-antibody scaffolds) comprising one or more non-native cysteine amino acid residues).

[0275] In some embodiments, conjugates may also be produced by reaction between an electrophilic group on a Targeting unit, such as an aldehyde or ketone carbonyl group, with a nucleophilic group on a Linker or Drug-Linker. In some cases, useful nucleophilic groups on a linker reagent include, but are not limited to, hydrazide, oxime, amino, hydrazine, thiosemicarbazone, hydrazine carboxyl, and arylhydrazide. In some cases, an antibody (or antigen binding portion thereof or other binding agent (including non-antibody scaffolds)) is modified to introduce electrophilic moieties that are capable of reacting with nucleophilic substituents on a Linker or Drug-Linker. In some cases, the sugars of glycosylated antibodies may be oxidized, e.g. with periodate oxidizing reagents, to form aldehyde or ketone groups which may react with the amine group of a Linker or Drug-Linker. In some cases, the resulting imine Schiff base groups may form a stable linkage, or may be reduced, e.g., by borohydride reagents to form stable amine linkages. In some cases, reaction of the carbohydrate portion of a glycosylated antibody with either galactose oxidase or sodium meta-periodate may yield carbonyl (aldehyde and ketone) groups in the antibody (or antigen binding portion thereof orother binding agent (including non-antibody scaffolds)) that can react with appropriate groups on the Linker or Drug-Linker (see, e.g., Hermanson, Bioconjugate Techniques).

[0276] In some embodiments, exemplary nucleophilic groups on a Drug, such as a cytotoxic agent, include, but are not limited to: amine, thiol, hydroxyl, hydrazide, oxime, hydrazine, thiosemicarbazone, hydrazine carboxyl, and arylhydrazide groups capable of reacting to form covalent bonds with electrophilic groups on a Linker including: (i) active esters such as NHS esters, HOBt esters, haloformates, and acid halides; (ii) alkyl and benzy l halides such as haloacetamides; (iii) aldehydes, ketones, carboxyl, and maleimide groups, ultimately forming a Drug-Linker or a conjugate.

[0277] In some embodiments, a Linker or Drug-Linker is attached to an interchain cysteine residue(s) of an antibody (or antigen binding portion thereof or other binding agent (including non-antibody scaffolds)). In some cases, the Linker or Drug-Linker typically comprises a maleimide group for attachment to the cysteine residues of an interchain disulfide. In some cases, a Linker or Drug-Linker is attached to a cysteine residue(s) of an antibody or antigen binding portion thereof.

[0278] The compounds of the present disclosure (e.g., drug linkers) may be prepared as described in the schemes and examples described elsewhere herein.

[0279] Drug linkers can be prepared as described in W02025014830A1.

[0280] The following examples further illustrate the invention but, of course, should not be construed as in any way limiting its scope.EXAMPLES

[0281] The following synthetic schemes are provided for purposes of illustration, not limitation. The following examples illustrate the various methods of making compounds described herein. It is understood that one skilled in the art may be able to make these compounds by similar methods or by combining other methods known to one skilled in the art. It is also understood that one skilled in the art would be able to make, in a similar manner as described below by using the appropriate starting materials and modifying the synthetic route as needed. In general, starting materials and reagents can be obtained from commercial vendors or synthesized according to sources known to those skilled in the art or prepared as described herein. As used below, and throughout the description of the invention, the following abbreviations, unless otherwise indicated, shall be understood to have the following meanings:PE petroleum etherPreparation of Drug LinkersExample 1: Synthesis of Drug-Linker compound 12

[0282] Drug-Linker compound 12 was prepared as shown in schemes 1 and 2.Scheme 16

[0283] To a solution of Fmoc-Sar6-COOH (1, synthesized on Cl-Trt resin using standard Fmoc SPPS protocol, 66 mg, 0.1 mmol) and compound 2 (HC1 salt, 22 mg. 0.1 mmol) in anhydrous DMF (2 mL) was added PyAOP (52 mg. 0. 1 mmol), followed by DIEA (0.07 mL). The mixture was stirred at room temperature for 10 mins. Piperidine (0. 1 mL) was added, and the reaction was stirred at room temperature for 20 mins. The crude reaction mixture was purified directly by RP-HPLC to give compound 3 as a white solid (TFA salt, 66 mg).

[0284] Fmoc-Glu(tBu)-Sar3-COOH (4, synthesized on Cl-Trt resin using standard Fmoc SPPS protocol. 60 mg) and compound 3 (66 mg) were dissolved in anhydrous DMF (2 mL). AOP (44 mg) and DIEA (0.05 mL) were added, and the reaction was stirred at room temperature. After 15 mins, the mixture was purified directly by RP-HPLC to give compound 5 as a white solid (110 mg).

[0285] The compound 5 (110 mg) was treated with TFA / DCM (1 / 1, v / v, 3 mL) at room temperature for 20 mins. The mixture was concentrated to dryness under reduced pressure to give compound 6 as a white solid.Scheme 2

[0286] To a solution of compound 7 (46 mg, Bioconjugate Chem. 2006, 17, 831-840) and exatecan mesylate (27 mg) in DMF (2 mL) was added DIEA (18 pL). The reaction mixture was stirred at room temperature (22 °C) for 5 hours and then piperidine (0. 1 mL) was added. The mixture was stirred at room temperature for 15 min and the crude was purified directly by RP- HPLC to give compound 8 as a yellow solid (45 mg).

[0287] Compound 6 (24 mg) and compound 8 (TFA salt, 22 mg) were dissolved in anhydrous DMF (1 mL). AOP (9 mg) was added, followed by DIEA (0.014 mL), and the mixture was stirred at room temperature. After 30 min, the crude product was purified by RP- HPLC to give compound 9 as a yellow solid (29 mg).

[0288] Compound 9 (28 mg) was suspended in MeOH / water (2 / 1, v / v, 3 mL), and sodium carbonate (12 mg) was added. The mixture was stirred at room temperature for 3 h. HC1 (aq. IN, 0.2 mL) was added, and the reaction mixture was evaporated to dryness under reduced pressure. The residue was dissolved in DMF (2 mL), and piperidine (0.04 mL) was added. After stirring at room temperature for 20 min, the crude was purified by RP-HPLC to give compound 10 (13 mg) as a yellow solid.

[0289] Compound 10 (13 mg) and the NHS ester 11 (3 mg) were dissolved in DMF (1 mL). and DIEA (0.005 mL) was added. After stirring at room temperature for 2 h, the mixture w as purified by RP-HPLC to give compound 12 as a yellow7solid (11 mg) after lyophilization. MS: m / z 1839.7 [M+H+]Example 2: Synthesis of Drug-Linker compound 25

[0290] Drug-Linker compound 25 was prepared as shown in scheme 3.Scheme 3

[0291] To a suspension of compound 13 (2.36 g, 7.59 mmol) in anhydrous DCM (30 mL) was added oxalyl chloride (3.85 L. 45.5 mmol) and DMF (65 pL). The mixture was stirred at room temperature over a period of 1 h. The solvent was removed under vacuum to give compound 14 as a yellow solid (2.5 g).

[0292] To a solution of compound 14 (200 mg, 1.2 mmol) in DCM (10 mL) and pyridine (3 mL) was added compound 15 (390 mg, 1.2 mmol). The mixture was stirred at room temperature for a period of 1 h. Then the mixture was evaporated and purified by RP-HPLC to give compound 16 as a tan solid (251 mg).

[0293] To a solution of compound 16 (251 mg, 0.54 mmol) in methanol (10 mL) was added formic acid (1 mL) and zinc powder (500 mg). The mixture was stirred for a period of 20 min, then filtered and purified by RP-HPLC to give compound 17 as a clear oil (60 mg).

[0294] To a solution of compound 17 (14 mg, 0.03 mmol) in 5mL of anhydrous DCM was added compound 18 (7.5 mg, 0.03 mmol) and EEDQ (8.0 mg, 0.03 mmol). The mixture was stirred at room temperature for a period of 24 h. Then the solvent was evaporated, and theresulting residue was purified by RP-HPLC to give compound 19 as a pale-yellow solid (8.6 mg).

[0295] To a solution of compound 19 (8.6 mg, 13.4 pmol) in anhydrous DMF (1.0 mL) was added bis(pentafluorophenyl) carbonate (10.6 mg. 26.8 pmol), and DIEA (2.3 pL, 13.4 pmol). The mixture was stirred at room temperature for a period of 24 h. Then the mixture was purified by RP-HPLC to give compound 20 as a tan solid (10 mg).

[0296] To a solution of compound 20 (10 mg, 11.7 pmol) in anhydrous DMF (1.0 mL) was added exatecan mesylate (6.22 mg, 11.7 pmol), and DIEA (10 pL). The mixture was stirred at room temperature for a period of 16 h. Then piperidine (50 pL) was added and the stirring continued for an additional 10 min. Then the mixture was purified by RP-HPLC to give compound 21 as a TFA salt (9.6 mg).

[0297] To a solution of compound 21 (TFA salt, 9.6 mg, 9.6 pmol) in anhy drous DMF (1 mL) was added compound 6 (11.3 mg, 9.6 pmol), PyAOP (4.3 mg, 9.6 pmol) and DIEA (10 pL). The mixture was stirred at room temperature for a period of 20 min. Then piperidine (50 pL) was added and the stirring continued for an additional 10 min. Then the mixture was purified directly by RP-HPLC to give compound 22 as a tan solid (14.8 mg).

[0298] To a solution of compound 22 (TFA salt, 14.8 mg. 7.7 pmol) in ACN (1.6 mL) and water (1.4 mL) was added 1 N NaOH in water (77 pL, 77 pmol) and the mixture was stirred at room temperature for a period of 60 min. Then the mixture was purified directly by RP-HPLC to give compound 23 as a white solid (9.6 mg).

[0299] To a solution of compound 23 (9.6 mg, 5.2 pmol) in anhydrous DMF (1 mL) was added compound 24 (1.75 mg. 5.2 pmol) and DIEA (4 pL). The mixture was stirred at room temperature for a period of 30 min. Then the mixture was purified directly by RP-HPLC to give compound 25 as an off-white solid (6.8 mg). MS: m / z 1874.0 [M+H+],Example 3: Synthesis of Drug-Linker compound 28

[0300] Drug-Linker compound 28 was prepared as shown in scheme 4.Scheme 4

[0301] To a solution of compound 21 (TFA salt, 26 mg, 26 pmol) in anhydrous DMF (2 mL) was added compound 26 (28 mg, 26 pmol), PyAOP (14 mg, 26 pmol) and DIEA (18 pL). The mixture was stirred at room temperature for a period of 30 min. Then piperidine (150 pL) was added and the stirring continued for an additional 10 min. Then the mixture was purified directly by RP-HPLC to give compound 27 as a TFA salt (33 mg, 69%). RP-HPLC method: Column: Phenomenex Gemini NX 5, C18, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (0.1% TFA), B) acetonitrile; and Gradient: 2-45% B over 20 min, flow 50 mL / min. The desired compound eluted at 20 min.

[0302] To a solution of compound 27 (TFA salt, 33 mg. 18 pmol) in anhydrous DMF (1 mL) was added compound 24 (6 mg, 18 pmol) and DIEA (8 pL). The mixture was stirred atroom temperature for a period of 20 min. Then the mixture was purified directly by RP-HPLC to give compound 28 as a pale-yellow solid (25 mg, 74%). MS: m / z 937.3 [M+2H+] / 2. RP-HPLC method: Column: Phenomenex Gemini NX 5, C18, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (0.1% TFA), B) acetonitrile; and Gradient: 5-60% B over 20 min, flow 50 mL / min. The desired compound eluted at 17 min.Example 4: Synthesis of Drug-Linker compound 31

[0303] Drug-Linker compound 31 was prepared as shown in scheme 5.Scheme 5

[0304] To a solution of compound 21 (TFA salt, 60 mg, 60 pmol) in anhydrous DMF (2 mL) was added compound 29 (61 mg, 60 pmol), PyAOP (32 mg, 60 pmol) and DIEA (42 pL). The mixture was stirred at room temperature for a period of 40 min. Then piperidine (150 pL)w as added and the stirring continued for an additional 10 min. Then the mixture was purified directly by RP-HPLC to give compound 30 as a TFA salt (68 mg, 64%). RP-HPLC method: Column: Phenomenex Gemini NX 5, C18, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (0.1% TFA), B) acetonitrile; and Gradient: 2-45% B over 20 min, flow 50 mL / min. The desired compound eluted at 19 min.

[0305] To a solution of compound 30 (TFA salt, 68 mg, 39 pmol) in anhydrous DMF (2 mL) was added compound 24 (13 mg, 39 pmol) and DIEA (14 pL). The mixture was stirred at room temperature for a period of 20 min. Then the mixture was purified directly by RP-HPLC to give compound 31 as a pale-yellow solid (53 mg, 75%). MS: m / z 1804.1 [M+H+], RP-HPLC method: Column: Phenomenex Gemini NX 5, C 18, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (0.1% TFA), B) acetonitrile; and Gradient: 5-55% B over 20 min, flow 50 mL / min. The desired compound eluted at 18 min.Example 5: Synthesis of Drug-Linker compound 34

[0306] Drug-Linker compound 34 was prepared as shown in scheme 6.Scheme 6

[0307] Compound 29 (110 mg) and compound 8 (TFA salt, 110 mg) were dissolved in anhydrous DMF (4 mL). AOP (52 mg) was added, followed by DIEA (0.06 mL), and the mixture was stirred at room temperature. After 90 min, the crude product was purified by RP- HPLC to give compound 32 as a yellow solid (116 mg). RP-HPLC method: Column: Phenomenex Gemini NX 5, C18, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (0.1% TFA). B) acetonitrile; and Gradient: 2-65% B over 20 min, flow 50 mL / min. The desired compound eluted at 19 min.

[0308] Compound 32 (116 mg) was suspended in MeOH / water (2 / 1, v / v, 6 mL), and sodium carbonate (36 mg) was added. The mixture was stirred at room temperature for 3 h. HC1 (aq. IN, 0.5 mL) was added, and the reaction mixture was evaporated to dryness under reduced pressure. The residue was dissolved in DMF (3 mL), and piperidine (0.06mL) was added. After stirring at room temperature for 20 min, the crude was purified by RP-HPLC to give compound 33 (52 mg) as a yellow solid. RP-HPLC method: Column: Phenomenex Gemini NX 5, C18, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (0.1% TFA), B) acetonitrile; and Gradient: 5-40% B over 20 min, flow 50 mL / min. The desired compound eluted at 18 min.

[0309] Compound 33 (51 mg) and the NHS ester (11, 9 mg) were dissolved in DMF (2 mL), and DIEA (0.018 mL) was added. After stirring at room temperature for 2 h, the mixture waspurified by RP-HPLC to give compound 34 as a yellow solid (33 mg) after lyophilization. MS: m / z 1768.7 [M+H+], RP-HPLC method: Column: Phenomenex Gemini NX 5, C18, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (0.1% TFA), B) acetonitrile; and Gradient: 5-60% B over 20 min, flow 50 mL / min. The desired compound eluted at 17 min.Example 6: Synthesis of Drug-Linker compound 37

[0310] Drug-Linker compound 37 was prepared as shown in scheme 7.Scheme 7

[0311] To a solution of compound 21 (TFA salt, 90 mg, 90 pmol) in anhydrous DMF (10 mL) was added compound 35 (70 mg, 90 pmol), PyAOP (47 mg, 90 pmol) and DIEA (80 pL). The mixture was stirred at room temperature for a period of 50 min. Then piperidine (700 pL) was added and the stirring continued for an additional 10 min. Then the mixture was purified directly by RP-HPLC to give compound 36 as a TFA salt (57 mg, 48%). RP-HPLC method: Column: Phenomenex Gemini NX 5, Cl 8, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (0.1% TFA), B) acetonitrile; and Gradient: 2-50% B over 20 min, flow 50 mL / min. The desired compound eluted at 20 min.

[0312] To a solution of compound 36 (TFA salt, 57 mg, 43 pmol) in anhydrous DMF (2 mL) was added compound 24 (15 mg, 43 pmol) and DIEA (30 pL). The mixture was stirred at room temperature for a period of 20 min. Then the mixture was purified directly by RP-HPLC to give compound 37 as a pale-yellow solid (53 mg, 75%). MS: m / z 1357.0 [M+H+], RP-HPLC method: Column: Phenomenex Gemini NX 5, C18, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (0.1% TFA), B) acetonitrile; and Gradient: 5-55% B over 20 min, flow 50 mL / min. The desired compound eluted at 18 min.Example 7: Synthesis of Drug-Linker compound 40

[0313] Drug-Linker compound 40 was prepared as shown in scheme 8.Scheme 7

[0314] Compound 35 (127 mg) and compound 8 (TFA salt, 220 mg) were dissolved in anhydrous DMF (5 mL). AOP (100 mg) was added, followed by DIEA (0. 14 mL), and the mixture was stirred at room temperature. After 2 h, the crude product was punfied by RP-HPLC to give compound 38 as a yellow solid (144 mg). RP-HPLC method: Column: Phenomenex Gemini NX 5, Cl 8, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (0.1% TFA), B) acetonitrile; and Gradient: 10-70% B over 20 min, flow 50 mL / min. The desired compound eluted at 18 min.

[0315] Compound 38 (144 mg) was suspended in MeOH / water (2 / 1, v / v, 8 mL), and sodium carbonate (45 mg) was added. The mixture was stirred at room temperature for 3 h. HC1 (aq. IN, 0.7 mL) was added, and the reaction mixture was evaporated to dryness under reduced pressure. The residue was dissolved in DMF (3 mL), and piperidine (0.046mL) was added. After stirring at room temperature for 20 min, the crude was purified by RP-HPLC to give compound 39 (68 mg) as ayellow solid. RP-HPLC method: Column: Phenomenex Gemini NX 5, C18, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (0.1% TFA), B) acetonitrile; and Gradient: 5-45% B over 20 min, flow 50 mL / min. The desired compound eluted at 18 min.

[0316] Compound 39 (68 mg) and the NHS ester (11, 17 mg) were dissolved in DMF (2 mL), and DIEA (0.03 mL) was added. After stirring at room temperature for 1 h, the mixturewas purified by RP-HPLC to give compound 40 as a yellow solid (51 mg) after lyophilization. MS: m / z 1322.5 [M+H+], RP-HPLC method: Column: Phenomenex Gemini NX 5, C18, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (10 mM NH4OAC), B) acetonitrile; and Gradient: 10-65% B over 20 min, flow 50 mL / min. The desired compound eluted at 18 min.Example 8: Synthesis of Drug-Linker compound 43

[0317] Drug-Linker compound 43 was prepared as shown in scheme 9.Scheme 9mL) was added compound 41 (33 mg, 26 pmol), PyAOP (14 mg, 26 pmol) and DIEA (18 pL). The mixture was stirred at room temperature for a period of 20 min. Then piperidine (150 pL) was added and the stirring continued for an additional 10 min. Then the mixture was purifieddirectly by RP-HPLC to give compound 42 as a TFA salt (30 mg, 58%). RP-HPLC method: Column: Phenomenex Gemini NX 5, C18, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (0.1% TFA), B) acetonitrile; and Gradient: 2-45% B over 20 min, flow 50 mL / min. The desired compound eluted at 20 min.

[0319] To a solution of compound 42 (TFA salt, 24 mg, 12 pmol) in anhydrous DMF (1 mL) was added compound 24 (4 mg, 12 pmol) and DIEA (6 pL). The mixture was stirred at room temperature for a period of 20 min. Then the mixture was purified directly by RP-HPLC to give compound 43 as a pale-yellow solid (20 mg, 81%). MS: m / z 1027.4 [M+2H+] / 2. RP-HPLC method: Column: Phenomenex Gemini NX 5, C18, 110 A, 150 x 50 mm; Instrument: Shimadzu LC with CTC IFC; Mobile phase: A) water (0.1% TFA), B) acetonitrile; and Gradient: 5-65% B over 20 min, flow 50 mL / min. The desired compound eluted at 16 min.Example 9: Preparation of Antibody-Drug-Conjugates

[0320] The conjugates were prepared using the followed conditions using the appropriate Drug-Linker and antibody.

[0321] 50 mg of mAb(s) for conjugation in various formulations were pH adjusted or buffer exchanged into 5% (v / v) 0.5 M Tris, 0.025 M EDTA, pH 8.5 formulations for reduction. The addition of 0.025 M EDTA in the formulation buffer was added to prevent metal-catalysed disulphide reoxidation. 10 mM TCEP (7 M eq.) was added to reduce a target number of interchain disulphide bonds and generate the desired average number of free thiols per mAb for 90 min at 25 °C. The free thiols were conjugated with an excess of maleimide (MC) containing toxin linker dissolved in a water miscible solvent (12 eq. of 20 mM MC-linker in 10% DMA) for 60 min at 25 °C. Extra solvent was added prior to toxin linker to maintain solubility of the toxin linker upon addition and mixing was performed utilizing stir flasks. Conjugation was ended by the addition of an excess of NAC (110 mM) and further stirred for 30 min to quench unreacted maleimide. Excess quenched toxin linker was removed by incubation with activated carbon for 60 min at room temperature at 15 rpm and / or diafiltration. Conjugates (yields, 93- 97%) were exchanged into the final formulation buffer (0. 1 M Arg / PBS, pH 7.4) and filtered through 0.22 pm PES before aliquoting and storage at < -60 °C.Example 10: Preparation of ADC-1 using Deruxtecan and UC-961 Antibody

[0322] ADC-1 was synthesized using Deruxtecan in combination with UC-961 antibody. Deruxtecan, is a drug-linker composed of an DX-8951 derivative (DXd), and a maleimide- GGFG peptide linker.Deruxtecan:

[0323] ADC-1 was prepared using example 9 and Deruxtecan and UC-961 antibody.DAR . wherein the DAR value as determined by RP-HPLC was 7.8.Example 11: Preparation of Antibody-drug conjugate ADC-2 using Drug-Linker 25 andUC-961 Antibody

[0324] ADC-2 was prepared using example 9 and the Drug-Linker 25 and UC-961 antibody.ADC-2; wherein the DAR value as determined by RP-HPLC was 7.9.Example 12: Preparation of Antibody-drug conjugate ADC-3 using Drug-Linker 12 andUC-961 Antibody

[0325] ADC-3 was prepared using example 9 and the Drug-Linker 12 and UC-961 antibody.ADC-3; wherein the DAR value as determined by RP-HPLC was 8.Example 13: Preparation of Antibody-drug conjugate ADC-4 using Drug-Linker 31 andPTK7 Antibody

[0326] ADC-4 was prepared using example 9 and the Drug-Linker 31 and PTK7-1 antibody.ADC-4; wherein the DAR value as determined by RP-HPLC was 8. The sequences of the heavy chain and light chain region of PTK7-1 antibody are shown in Table 7 (VH SEQ ID NO: 193 and VL SEQ ID NO: 188).Example 14: Preparation of Antibody-drug conjugate ADC-5 using Drug-Linker 37 andPTK7 Antibody

[0327] ADC-5 was prepared using example 9 and the Drug-Linker 37 and PTK.7-1 antibody.ADC-5: wherein the DAR value as determined by RP-HPLC was 8. The PTK7-1 antibody is shown in Table 7 (VH SEQ ID NO: 193 and VLSEQ ID NO: 188).Example 15: Preparation of Antibody-drug conjugate ADC-6 using Drug-Linker 37 andROR2 Antibody

[0328] ADC-6 was prepared using example 9 and the Drug-Linker 37 and ROR2 antibody.ADC-6wherein the DAR value as determined by RP-HPLC was 8.Example 16: Preparation of Antibody-drug conjugate ADC-7 using Drug-Linker 31 andROR2 Antibody

[0329] ADC-7 was prepared using example 9 and the Drug-Linker 31 and ROR2 antibody .ADC-7Example 17: Preparation of ADC-8 to ADC-20 using Drug-Linker Phe-C3-GGFG andPTK7-2 to PTK7-14

[0330] ADC-8 to ADC-20 were prepared using example 9 and the Drug-Linker Phe-C3-GGFG and PTK7-2 to PTK7-14 antibodies, respectively.Drug-Linker

[0331] ADC-8 was prepared using example 3 and Drug-Linker Phe-C3-GGFG and PTK7-2 antibody.wherein the DAR value as determined by RP-HPLC was 7.4. The PTK7-2 antibody is shown in Table 7 (Vn SEQ ID NO: 148 and VLSEQ ID NO: 147).

[0332] ADC-9 was prepared using example 9 and Drug-Linker Phe-C3-GGFG and PTK7-3 antibody.as determined by RP-HPLC was 7.7. The PTK7-3 antibody is shown in Table 7 (VH SEQ ID NO: 10 and VLSEQ ID NOV).

[0333] ADC-10 was prepared using example 9 and Drug-Linker Phe-C3-GGFG and PTK7-4 antibody.wherein the DAR value as determined by RP-HPLC was 7.8. The PTK7-4 antibody is shown in Table 7 (VH SEQ ID NO: 16 and VLSEQ ID NO: 15).

[0334] ADC-11 was prepared using example 9 and Drug-Linker Phe-C3-GGFG and PTK7-5 antibody.wherein the DAR value as determined by RP-HPLC was 7.6. The PTK7-5 antibody is shown in Table 7 (VH SEQ ID NO: 18 and VLSEQ ID NO: 17).

[0335] ADC-12 was prepared using example 9 and Drug-Linker Phe-C3-GGFG and PTK7-6 antibody.determined by RP-HPLC was 7.5. The PTK7-6 antibody is shown in Table 7 (VH SEQ ID NO:20 and VLSEQ ID NO: 19).

[0336] ADC-13 was prepared using example 9 and Drug-Linker Phe-C3-GGFG and PTK7-7 antibody.value as determined by RP-HPLC was 7.6. The PTK7-7 antibody is shown in Table 7 (VH SEQ ID NO:26 and VLSEQ ID NO:25).

[0337] ADC-14 was prepared using example 9 and Drug-Linker Phe-C3-GGFG and PTK7-8 antibody.wherein the DAR value as determined by RP-HPLC was 7.5. The PTK7-8 antibody is shown in Table 7 (VH SEQ ID NO:30 and VLSEQ ID NO:29).

[0338] ADC-15 was prepared using example 9 and Drug-Linker Phe-C3-GGFG and PTK7-9 antibody.wherein the DAR value as determined by RP-HPLC was 7.6. The PTK7-9 antibody is shown in Table 7 (VH SEQ ID NO:76 and VLSEQ ID NO:75).

[0339] ADC-16 was prepared using example 9 and Drug-Linker Phe-C3-GGFG and PTK7- 10 antibodv.wherein the DAR value as determined by RP-HPLC was 7.6. The PTK7-2 antibody is shown in Table 7 (VH SEQ ID NO: 148 and VLSEQ ID NO: 147).

[0340] ADC-17 was prepared using example 9 and Drug-Linker Phe-C3-GGFG and PTK7- 11 antibody.wherein the DAR value as determined by RP-HPLC was 7.3. The PTK7-11 antibody is shown in Table 7 (VH SEQ ID NO : 110 and VLSEQ ID NO : 109).

[0341] ADC-18 was prepared using example 9 and Drug-Linker Phe-C3-GGFG and PTK7- 12 antibodv.wherein theDAR value as determined by RP-HPLC was 7.3. The PTK7-12 antibody is shown in Table 7 (VHSEQ ID NO: 86 and VLSEQ ID NO: 85).

[0342] ADC-19 was prepared using example 9 and Drug-Linker Phe-C3-GGFG and PTK7- 13 antibody.wherein the DAR value as determined by RP-HPLC was 7.6. The PTK7-13 antibody is shown in Table 8 (VH SEQ ID NO: 128 and VLSEQ ID NO: 127).

[0343] ADC-20 was prepared using example 9 and Drug-Linker Phe-C3-GGFG and PTK7- 14 antibody.wherein the DAR value as determined by RP-HPLC was 7.7. The PTK7-14 antibody is shown in Table 7 (VHSEQ ID NO: 122 and VLSEQ ID NO: 121).Example 16: Preparation of ADC-21 to ADC- 24 using Drug-Linker C2-GGFG and PTK7-2, PTK7-9, PTK7-10, and PTK7-13

[0344] ADC-21 to ADC-24 were prepared using example 9 and the Drug-Linker C2-GGFG and PTK7-2, PTK7-9, PTK7-10. and PTK7-13 antibodies, respectively.Drug-Linker

[0345] ADC-21 was prepared using example 9 and Drug-Linker C2-GGFG and PTK.7-2 antibody.w .herein the DAR value as determined by RP-HPLC was 7.9. The PTK7-2 antibody is shown in Table 7 (VHSEQ ID NO: 148 and VLSEQ ID NO: 147).

[0346] ADC-22 was prepared using example 9 and Drug-Linker C2-GGFG and PTK.7-9 antibody.wherein the DAR value as determined by RP-HPLC was 7.9. The PTK7-9 antibody is shown in Table 7(VH SEQ ID NO:76 and VL SEQ ID NO:75).

[0347] ADC-23 was prepared using example 9 and Drug-Linker C2-GGFG and PTK7-10 antibody.value as determined by RP-HPLC was 7.9. The PTK7-10 antibody is shown in Table 7 (VH SEQ ID NO: 112 and VLSEQ ID NO: 111).

[0348] ADC-24 was prepared using example 9 and Drug-Linker C2-GGFG and PTK7-13 antibody.wherein the DAR value as determined by RP-HPLC was 7.9. The PTK7-13 antibody is shown in Table 7 (VH SEQ ID NO: 128 and VLSEQ ID NO: 127).Example 17: Preparation of ADC-25 using Drug- Linker C5-GGFG and PTK7-9EL

[0349] ADC-25 was prepared using example 9 and the Drug-Linker GGFG-SN38 andPTK7-9EL antibody.Drug-Linker

[0350] ADC-25 was prepared using example 9 and Drug-Linker GGFG-SN38 and PTK7- 9EL antibody.wherein the DAR value as determined by RP-HPLC was 7.9. The PTK7-9EL antibody is shown in Table 7 (VHSEQ ID NO:76 and VLSEQ ID NO:75).Example 18: Preparation of ADC-26 and ADC-27 using Drug-Linker Dipeptide-1 andPTK7-9EL and PTK7-1EL

[0351] ADC-26 and ADC-27 were prepared using example 9 and the Drug-Linker Dipeptide-1 and PTK7-9EL and PTK7-1EL antibodies, respectively.Drug-Linker Dipeptide-

[0352] ADC-26 was prepared using example 9 and Drug-Linker Dipeptide-1 and PTK7-9EL antibody.wherein the DAR value as determined by RP-HPLC was 3.4. The PTK7-9EL antibody is shown in Table 7 (VH SEQ ID NO:76 and VLSEQ ID NO:75).

[0353] ADC-27 was prepared using example 9 and Drug-Linker Dipeptide-1 and PTK7-1EL antibody.wherein the DAR value as determined by RP-HPLC was 3.2. The PTK7-1EL antibody is shown in Table 7 (VH SEQ ID NO: 193 and VLSEQ ID NO: 188).Example 19: Preparation of ADC-28 using GGFG-Exatecan and PTK7-1 Antibody

[0354] ADC-28 was prepared using example 9 and Deruxtecan and PTK7-1 antibody.wherein the DAR value as determined by RP-HPLC was 7.9. The PTK7-1 antibody is shown in Table 7 (VH SEQ ID NO: 193 and VLSEQ ID NO: 188).Example 20: Preparation of ADC-29 using Deruxtecan and PTK7-1 Antibody

[0355] ADC-29 was prepared using example 9 and Deruxtecan and PTK7-9EL antibody.wherein the DAR value as determined by RP-HPLC was 8.0. The PTK7-9EL antibody is shown in Table 7 (VHSEQ ID NO: 76 and VLSEQ ID NO:75).Characterization of ConjugatesExample 20: Plasma stability

[0356] The plasma stability tests illustrate the stability of the various ADCs in mouse and human plasma. ADCs 1-6 were tested in both mouse and human plasma.

[0357] ADCs were incubated in IgG depleted plasma at a concentration of 50 pg / mL in a volume of 300 pL. IgG depletion had been performed using a HiTrap Protein G Column (Cytiva). The samples were incubated at 37 °C in Eppendorf tubes for periods of 0. 1, 3, 7 and 15 days. After the appropriate time incubation, samples were transferred to a -80 °C freezer until they could be processed. Samples were incubated in each timepoint in duplicate.

[0358] To separate the ADCs from the plasma, 100 pL of each sample were mixed with 100 pL Protein A magnetic bead slurry' (Thermo Pierce) and 900 pL of Sodium Phosphate (50 mM, pH7) with shaking for two hours at room temperature. The ADC should then bind to the beads allowing the excess plasma to be discarded. The beads were then washed to remove nonspecific binding with ImL of 0.1 % Triton, 0.1 % IP A, and then twice in ImL PBS for 30 minutes each ith shaking. The ADC w as then eluted from the beads in 100 pL of a low' pH, high organic mix (40mM Glycine, 2% Formic Acid 50% Acetonitrile) for 60 minutes. The bead slurry was then centrifuged and 50 pL supernatant was injected onto the LC-MS.

[0359] The LC used a 50 mm x 2. 1 bioZen XB-C8 column over a seven-minute gradient of H2O and Acetonitrile each with 0.1% formic acid. The MS was operated in intact protein mode with a source temperature of 500 °C, delustering potential of 200 V, and a mass range of 900- 4500 m / z.

[0360] Processing was performed in Sciex OS allowing the addition of up to four payloadlinkers per protein. Stability results were shown in FIG. 1, for mouse plasma and FIG. 2, for human plasma.

[0361] As shown in FIG. 1, the stability of the ADC-1, ADC-2, and ADC-3 in mouse plasma were obtained. Additionally, as shown in FIG. 2, the stability of ADC-1, ADC-2, and ADC-3 in human plasma were obtained.Example 21: Cellular Binding

[0362] The ability of an anti-UC-961 conjugate to bind to Jeko-1 cells was measured using in vitro cellular binding assay.

[0363] For each Jeko-1 cell line, 0.5 million cells were plated in 50 pL on each well of a 96- well deep-well plate (Thermo Scientific #249946). A 1:3 dilution series of primary antibody was made starting with 1-pg / mL starting stock. Thereafter, 50 pL of different concentrations of primary’ antibody (from 17 pg / mL to 1000 ng / mL final concentration) were placed over the 50 pL containing the cells. Cells and antibodies w ere mixed and incubated on ice for 20 minutes. For the first w ash, 300 pL of FACS buffer w as added and cells were centrifuged at 500 x g for 5 minutes at 4 °C. The supernatant was discarded, and cells were resuspended in 400 pL of FACS buffer for an additional wash. After the second wash, cells were resuspended in 100 pL of goat anti -human IgG secondary phycoerythrin (PE) antibodies (ThermoFisherScientific #12-4998-82) at 1 pg / mL final concentration and incubated on ice (in the dark) for 20 minutes. Cells were washed twice as described previously and analyzed on the BD FACSVerse with Flowjo software, Version 10. The percentage of maximal binding relative to the highest concentration was graphed and half-maximal effective concentrations (ECso) values were determined using GraphPad Prism Version 7 and shown in Table 1 and binding percentage of each ADC plotted in FIG. 3. FIG. 4 shows the mean fluorescence intensity of each ADC.Table 1.Example 22: Cytotoxicity measurement

[0364] The ability of an anti-UC-961 conjugate to inhibit cell grow th was measured using in vitro cytotoxicity assay.

[0365] Jeko-1 cells were cultured in log phase growth and split into 96-well plates. Each cell-line was plated at a slightly different concentration but ranged from 5xl03to50x104cells / well. Cells, in duplicate, were incubated with 3-fold serial dilution of a particular immunoconjugate starting at 3000 or 1000 nanomolar (3000, 1000, 333, 111, 37, 12.3, 4.1, 1.37, 0.46, 0.15 nanomolar) for 72 hours at 37° C and 5% CO2. After treatment the cells w ere incubated with an equal volume of CellTiter-Glo® reagent (Promega Inc.) for 15 minutes at room temperature, and viability was determined by a luminometer. EC50 values were shown in Table 2 and percentage of inhibition plotted in FIG. 5.Table 2.Example 23: Internalization

[0366] MDA-MB-468 cells were harvested, washed with cold PBS and resuspended at a concentration of 1 x 107cells / mL in cold FACS buffer comprising PBS and 2% FBS. Aliquots of 1 x io6cells were added to microcentrifuge tubes or wells. Primary antibody was diluted to create 10x stock solutions of 300 pg / mL or 1 mg / mL to allow' addition of 10 pl of each solution to the appropriate tubes.

[0367] Control groups comprised of unstained and secondary antibody only (goat antihuman IgG-PE, Fc-gamma specific) (ThermoFisher Scientific #12-4998-82). Test groups comprised cells subjected to the following conditions with evaluation at 30 pg / mL (203 nM) or 100 pg / mL (676 nM) of primary antibody depending upon the experiment: Cells were kept on ice for 20 minutes in addition to controls centrifuged at 300 x g for 4 minutes, washed twice with 200 pl FACS buffer, resuspended in 100 pl of FACS buffer, and incubated at 37°C for 30, 60, 120, or 240 minutes. After incubation, cells w ere centrifuged at 250 x g and washed twice with FACS buffer and resuspended in 100 pl of FACS buffer. A 10x stock of the secondary antibody was diluted 1:2000 in FACS buffer and 10 pl per tube was added to the appropriate tubes. Cells were incubated on ice for 20 minutes, washed twice with FACS buffer and resuspended in 100 pl of fixation buffer (4% paraformaldehyde in PBS). FACS analysis w asthen performed, assessing median fluorescence intensify (MFI). The relative magnitude of primary antibody internalization was determined by comparing MFI values for each timepoint with that for the primary antibody control at Time 0 are shown in FIG. 6.Example 24: DAR by RP-HPLC

[0368] RP-HPLC of the ADCs was used to determine the drug to antibody ratio (DAR) of each ADC. As shown in the below7Table 4, reversed phase HPLC was used to obtain the drug to antibody ratio (DAR) of the ADCs.

[0369] RP-HPLC conditions: Column - Phenomenex Kinetex 100 A. 50 x 4.6 mm, 2.6 pm, Part Number: PL1912-1502. MPA - 0.1% TFA / H20, MPB - 0. 1% TFA / CAN

[0370] Method: Flow rate - 1 mL / min, Gradient - see Table 3. Column temp. - 50 C.

[0371] Sample temp - 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 1.2 nm, slit 8 nm.

[0372] Sample - neat injection, ~ 5 pg.Table 3: RP-HPLC Method Flow rate GradientTable 4B: DAR of Various ADCs generated from PTK7 antibodyExample 25: Hydrophobicity of drug-linkers by RP-HPLC analysis

[0373] As shown in Table 5, reversed phase HPLC analysis was used to obtain the relative hydrophobicity of the drug-linkers.

[0374] Column - Phenomenex Kinetex 100 A, 50 x 4.6 mm, 2.6 pm, Part Number: 00B- 4497-EO. MPA - 0.05% TFA / H20, MPB - 0.05% TFA / CAN.

[0375] Method: Flow rate - 2 mL / min. Gradient - see Table 6. Column temp. - 60 C. Sample temp - RT. DAD 214 nm, BW 4 nm + 360 nm, BW 4 nm. Reference 440 nm, BW 40 nm. Peak width > 0.1 min (2 s response time (2.5 Hz). Spectrum: 200 - 400 nm, step 2 nm, slit 2 nm

[0376] Sample - Injection mass, 5 - 100 pmols, dilution of DMA toxin stock in MeOH.

[0377] Table 6 show s the retention times of the various Drug-Linkers. Drug-Linkers Deruxtecan, 18, 25, 34, 37, 40, 43, and 58 were synthesized as enantiomers hence the two retention time values. Based off the first retention times for each Drug-Linker from the RP- HPLC. the hydrophobicity increases as follows: 12 < 25 < Deruxtecan. The drug-linker 25 shorter sulphate side chain demonstrates that the benefits of increasing the hydrophilicity, which in turn increases the ADC’s T1 / 2 life and AUC, and ultimately its in vivo efficacy, is more of an overall ionic effect and less of a physical masking effect of a larger side chain.Table 5: RP-HPLC Method Flow rate GradientTable 6: Retention Tinies of Drug-Linkers using RP-HPLCExample 26: Payload release

[0378] Conjugates were incubated with papain or (3-glucuronidase buffer overnight and monitored for the release of exatecan. A stock of papain at lOmg / ml in l. lmM EDTA, 0.067 mM DTT and 5.5 mM Cysteine was prepared. 50 pg of ADC (10 pl) and 1 pl of papain stock so the final concentration was 1 mg / ml. incubated at 37 °C for 4 hours before analysis. As shown in FIG. 7, XIC for all samples show a strong signal for release of payload. All six ADCs present a peak at 436. 16 (matching a MSMS fragment assigned to exatecan).Example 27: Pharmacokinetics Preparation

[0379] a-HuRORl ELISA (“Total ADC”) Procedure: wells of a 96-well plate were coated with biotin-RORl antigen (Biotinylated Human / Cynomolgus / Rhesus macaque ROR1 Protein, Avitag™; 200 ug / ml, AcroBiosystem) at 0.2 pg / well / 25 pl and place overnight at 4 °C. The wells were then washed with 100 pl / well Washing Buffer for 4 times and blocked with 5%MILK + PBS for 90 min at 37 °C . A standard curve of ADC-Dxd and / or ADC-Exatecan (25 pl / well) were added as well as the diluted mouse plasma PK samples. The plate was incubated at 37 °C for 60 min and subsequently washed. 25 pl / well of Goat anti-Human Kappa- HRP (Sothembiotech, cat#2061-05, Lot# H519-YD22B) at 1: 5,000 - 1: 20,000 dilution was added, and the plate was incubated for 60 min at 37 °C . The plate was then washed and developed in TMB / Stop solution and read on the Spectramax at 450 OD.

[0380] a-Dxd ELISA (“Free Payload”) Procedures: 0.2 pg / well / 25 ul of biotin-RORl for antigen coating o / n 4 °C . (Biotinylated Human / Cynomolgus / Rhesus macaque ROR1 Protein, Avitag™; 200 ug / ml, AcroBiosy stem). Wash with 100 pl per well Washing Buffer for 4 times. Block with 5%MILK+PBS 90 min 37 °C . Add 25 pl of ADC-Dxd and / or ADC-Exatecan as standards and mouse plasma samples. Incubate 60 min 37 °C . Washing was performed. Add anti-Dxd (0.025 ug / 25 ul / well; AcroBiosystems, cat# DXD-S222) 60 min 37. Washing was then performed. Goat a-Mouse-Kappa-HRP was added @ 1 : 5K - 1 : 20. (Bethyl Lab, 1 mg / ml, Lot#33, Cat#A90-l 19P). Washing was then performed. Develop in TMB / Stop Soln and was read @ OD 450. “Free Payload’' = anti-HuRORl ELISA Values (“Total’' ADC ) - anti-Dxd ELISA Values (ADCs containing Payloads).Example 28: Calculation of Pharmacokinetic Parameters

[0381] Pharmacokinetic analyses were performed on plasma concentration-versus-time data for all analytes using Phoenix WinNonlin (v 7.0) non-compartmental analysis function (linear trapezoidal rule for AUC calculations). Nominal dose values and sampling times were used forcalculations. For the purpose of PK calculations, any concentration reported as ‘BLQ” w as set equal to zero. As the data permitted, the terminal rate constant (lambda z, Xz) for each of the analytes was determined. The value of Xz was calculated by the slope of the regression line of the natural log transformed concentrations vs. time with the following constraints: Data points were randomly distributed around a single straight line; At least three data points post the Cmax were used in the regression; The correlation coefficient (R2) of regression was >0.90; The period over which the regression is determined was at least 2-fold greater than the calculated half-life itself.

[0382] To optimize the reliability of the identified terminal phase (Xz), the data points used to define the Xz were manually selected. When lambda z profiles did not meet the guidelines stated above, the AUCINF, tl / 2, CL, or Vz parameters for that animal profile were not reported. When possible, AUCINF was calculated as: AUClast + (Clast / Xz). CL was calculated as: Dose / (AUCINF) and Vz was calculated as: Dose / (AUCINF * Xz). Terminal half-life (tl / 2) was calculated as: ln(2) / Xz. Mean plasma concentration-versus-time data are presented as mean only (N=2) and are reported to 3 significant figures. PK parameter values are presented as mean only (N=2). Individual Tmax (where applicable) and tl / 2 values are reported to 2 significant figures, while all other values are reported to 3 significant figures. Pharmacokinetic data was presented in FIG. 8.Example 29: In Vivo efficacy

[0383] The antitumor activity of ADCs was evaluated in the xenograft models of H1975 non- NSCLC, H520 NSCLC, LCLC-103H (NSCLC), Hep3B (liver), Dul45 (prostate), MDA- MB-486 (breast), PA-1 (ovarian), TNBC PDX, SA4121 PDX (sarcoma), OV14661 PDX (ovarian), and HN0635 PDX (head and neck). The tumor bearing mice were randomized based on their individual tumor and given iv injection dose. As shown in FIG. 9, at 10 mg / kg, once weekly iv injection dose for 3 weeks (days 0, 8, 16), ADCs were shown to have antitumor activity in H1975 model. Whereas in FIG. 10, at 10 mg / kg, once weekly iv injection dose for 3 weeks (days 0, 8, 16), ADCs were shown to have antitumor activity in H520 model. In FIG. 11, at 10 mg / kg, once weekly iv injection dose for 3 weeks (days 0, 8, 16), ADCs were shown to have antitumor activity in LCLC-103H model. As shown in FIG. 12. at 5 mg / kg once weekly iv injection dose for 2 weeks (days 1, 8), 12 PTK.7 ADCs demonstrated broad range of antitumor activities in Hl 975 model. As shown in FIG. 13, at 2.5 mg / kg, 5 mg / kg, and 10 mg / kg once weekly iv injection dose for 4 weeks (days 1, 8, 15, 22), ADCs were shown to have antitumor activity in H1975 model. Whereas in FIG. 14, at 5 mg / kg once weekly iv injection dose for 3 weeks (days 1. 8. 15), ADC-22 showed improved antitumor activity in Hl 975 model ascompared to ADC-21. In FIG. 15, at 15 mg / kg or 30 mg / kg single iv injection dose, ADCs were shown to have antitumor activity in Hep3B (liver) model. In FIG. 16, at 15 mg / kg or 30 mg / kg single iv injection dose, ADCs were shown to have antitumor activity in Dul45 (prostate) model. As shown in FIG. 17, at 5 mg / kg once weekly iv injection dose for 3 weeks (days 1, 8, 15), ADCs with either chimeric or humanized version of a PTK.7 antibody showed antitumor activity in H520 model. In FIG. 18, at 10 mg / kg once weekly iv injection dose for 3 weeks (days 1, 8, 15), ADCs were shown to have antitumor activity in H520 model. As shown in FIG. 19, at 10 mg / kg once weekly iv injection dose for 3 weeks (days 1, 8, 15), ADCs were shown to have antitumor activity in LCL-103H model. In FIG. 20, at 2.5 mg / kg, 5 mg / kg, or 10 mg / kg once weekly iv injection dose for 3 weeks (days 1, 8, 15), ADCs displayed antitumor activity in MDA-MB-468 (breast) model. As displayed in FIG. 21, at 2.5 mg / kg, 5 mg / kg, or 10 mg / kg once weekly iv injection dose for 3 weeks (days 1, 8, 15), ADCs displayed dose dependent antitumor activity in LCL-103 model. In FIG. 22. at 5 mg / kg or 10 mg / kg single iv injection dose. ADC-4 showed antitumor activity in PA-1 (ovarian) model. Whereas in FIG. 23, at 5 mg / kg, 10 mg / kg, or 20 mg / kg single iv injection dose, ADC-4 showed antitumor activity in LCLC-103H model. Shown in FIG. 24, at 5 mg / kg or 10 mg / kg once weekly iv injection dose for 4 weeks (days 1, 8, 15, 22), ADC-4 showed antitumor activity in TNBC PDX model. In FIG. 25, at 10 mg / kg once weekly iv injection dose for 4 weeks (days 1, 8. 15, 22), ADC-4 showed antitumor activity in SA4121 PDX (sarcoma) model. As shown in FIG. 26, at 10 mg / kg once weekly iv injection dose for 4 weeks (days 1, 8, 15, 22), ADC-4 showed antitumor activity in OV14661 PDX (ovarian) model. Whereas in FIG. 27, at 10 mg / kg once weekly iv injection dose for 4 weeks (days 1, 8, 15, 22), ADC-4 showed antitumor activity in HN0635 PDX (head and neck) model.

[0384] LCLC: large-cell lung cancer tumors; NSCLC; non-small cell lung tumors; TNBC: Triple negative breast cancer; SCLC: small cell lung tumors; and PDX: patient-derived xenograft.Example 30: PTK7 Antibody DiscoveryImmunization

[0385] Four hyperimmune mice (DiversimAb™, Abveris) were immunized with 50 pg of recombinant PTK7 extracellular domain (ECD) protein (ACROBiosystems, cat. #PT7- H52H3). Following the initial immunization, mice were boosted every 2-3 days for 7-10 additional injections. Additionally, five humanized transgenic mice (ATX-GK-mix, Alloy) were immunized with 25 pg recombinant PTK7 ECD using Complete Freund’s adjuvant. Followingthe initial immunization, mice received 4-7 weekly boosts with 25 jug recombinant PTK7 ECD using Incomplete Freund’s adjuvant.Titer check

[0386] Mouse serum titers were checked by ELISA assay. A high binding ELISA plate was coated with 1 pg / mL antigen overnight at 4°C. Both human PTK7-Fc tagged (R&D Systems, cat. #9799-TK-050) and cynomolgus PTK7 his-tagged (ACROBiosystems, cat. #PT7- C52h3) antigen were used. The coating material was aspirated and the wells were blocked with 2% BSA in PBS for Ih at 25°C. The blocking material was removed and 3-fold serial dilutions of sera, beginning at 1 : 100, in blocking solution were added and incubated at 25°C for Ih. The plate was washed four times with PBS containing 0.05% Tween20 (PBST) and HRP-goat antimouse IgG, Fcy-specific antibody diluted 1:20,000 in blocking solution was added and incubated at 25°C for 45 min. The plate was washed five times with PBST and 3,3 ’,5,5’- tetramethylbenzidine (TMB) substrate was added. The reaction was terminated with stop solution and the plate was read at 450 nm. Normal mouse serum (strain matched) was included as a background control. For comparison, three PTK7 control antibodies were serially diluted 3- fold, beginning at 10 pg / mL.

[0387] The serum titers were also checked for binding to cell lines expressing PTK7 (Jurkat. H520, HCC1428) or not expressing PTK7 (Ramos). Briefly. 100,000 cells were seeded per well, and subsequently, were resuspended in 100 pL of titrated serum, starting at 1 : 100 dilution in 2% BSA in PBS and 3-fold serially diluted for 11 points. The samples were incubated on ice for 2h, washed, were resuspended in 50 pL of secondary antibody (Alexa Fluor® 488 AffiniPure™ goat anti-mouse IgG, Fey fragment specific, Jackson cat. #115-545- 071) and were incubated for 30 min on ice. The cells were washed and read on an iQue flow cytometer. Normal mouse serum (strain matched) was included as a background control.

[0388] Mice with signals about 10-fold above background on antigen (strain-matched normal serum) at 1:8100 dilution were used for B cell isolation. Mice that were not used for B cell isolation due to low titers continued to be immunized and serum titers were re-checked 4-5 weeks later.Initial Screening

[0389] Following immunization, B cells were isolated from plasma, spleen and lymph nodes and single B cell screening was performed using the Beacon® Optofluidic System (Berkeley Lights). Using a multiplex assay, cells were screened for IgG secretion, binding to recombinant human PTK7 (extra-cellular domain), binding to recombinant cynomolgus PTK7 (extra-cellular domain), binding to Jurkat cells (express PTK7), and binding to Ramos cells (no PTK7 expression). Isolated B cell clones with different binding profiles were prioritized forantibody sequencing. All selected clones secreted IgG and were negative for binding to Ramos cells. Priority 1 clones were reactive with recombinant human and cynomolgus PTK7 and bound Jurkat cells. Priority 2 clones were reactive with recombinant human and bound Jurkat cells. Priority 3 clones bound Jurkat cells but were unreactive with recombinant PTK7. Complete VH and VL sequences were obtained for 73 antibodies. The antibodies isolated from Beacon® screening are summarized in Table 7. Control anti-huPTK7 antibodies 188B (Miltenyi Biotec cat. #130-091-578; mouse IgG2a), OTI2E7 (Invitrogen cat. #MA5-25774; mouse IgGi) and hu24 (U.S. Pat. No. 9,777,070; humanized murine antibody; VH and VL sequences shown in the sequence table below) are listed at the bottom of Table 7.Table 7. Antibodies and Corresponding SequencesExample 31: Secondary Screening and Characterization

[0390] Initially, 48 clones were selected for further characterization and were expressed as human IgGi using Expi293 cells. The antibodies were purified in a single step using MabSelect PrismA™ protein A chromatography resin (Cytiva) and the final buffer composition was 65 mM Tris, 10 mM glycine, pH 6.0.

[0391] Binding of the antibodies to four tumor cell lines expressing PTK7 (Jurkat, NCI- H520, OVCAR3, HCC1428) and one tumor cell line not expressing PTK7 (Ramos) was assessed by flow cytometry'. Jurkat is a human T lymphocyte cell line. NCI-H520 is a humannon-small cell lung cancer line. OVCAR3 is a human high-grade serous ovarian adenocarcinoma cell line. HCC1428 is a human epithelial adenocarcinoma cell line. Ramos (RA-1) is a human B lymphocyte cell line.

[0392] The binding of all antibodies was tested at a single concentration (10 pg / mL).Briefly, cells were seeded at 100,000 cells per well and were resuspended in 100 pL of purified IgG at 10 pg / mL. The cells were incubated with the antibody for 30 min on ice, washed two times with 100 pL 1% BSA in PBS, washed once with 150 pL 1% BSA and were resuspended in 50 pL of Alexa Fluor® 488 AffiniPure™ goat anti-mouse IgG, Fey fragment specific (Jackson cat. #115-545-071) diluted in 1% BSA in PBS, and were incubated on ice for an additional 30 min. Control anti-PTK7 antibodies 188B, OTI2E7 and hu24 were also tested at 10 pg / mL. The MFI values obtained are summarized in Table 8. In general, NCI-H520 cells displayed the highest MFI values with most antibodies tested while HCC1428 cells displayed the lowest MFI values. However, certain antibodies displayed different staining patterns. For example, control antibody OTI2E7 and several discovered antibodies (e g., D4D88936-3188, D3D88936-15092, D4D88936-1474, and D4D88750-935) displayed higher binding signals with OVCAR3 cells than with NCI-H520 cells. Several antibodies that displayed strong binding to all four tumor cell lines, but not Ramos cells, were identified (e g., D4D88750-9185, D4D88750-11630, D4D88936-3188, D3D88936-15092, D4D88936-1474, D3D88936-18327, and D4D88750-935). Some antibodies, such as D3D88936-15092, D4D88936-3188, D3D88936-18327 and D4D88750-935, displayed superior binding to tumor cells over control antibody 188B.Table 8. Flow Cytometry Analysis of Binding to Cell Lines

[0393] Twelve additional clones were selected for characterization and were expressed as human IgGi using Expi293 cells. Binding of these antibodies to the four tumor cell lines expressing PTK7 (Jurkat, NCI-H520, OVCAR3, HCC1428) and one tumor cell line not expressing PTK7 (Ramos) was assessed by flow cytometry, as described above. The MFI values obtained are summarized in Table 9. For this set of antibodies, OVCAR3 cells generally- displayed the highest MFI values while HCC1428 cells displayed the lowest expression. However, similar to the first panel of antibodies tested, the antibodies displayed different relative binding patterns across the various cell lines tested. Multiple antibodies that displayed strong binding to all four tumor cell lines, but not Ramos, cells were identified (e.g., D2D77808- 5632, D2D77808-3707, and D2D77808-7380).Table 9. Flow Cytometry Analysis of Binding to Cell Lines

[0394] Next, the binding kinetics of the antibodies to human and cynomolgus recombinant PTK7 was characterized using the Octet® bio-layer interferometry (BLI) platform (Sartorius). Individual anti-human biosensors were loaded with purified human IgG samples. Following establishment of the loading baseline, the sensors were exposed to human PTK7 (His-tagged, at 250 nM) and the association rates were measured. The biosensors were moved to a buffer well to measure the dissociation rate of target antigen from the immobilized antibody. The biosensors were regenerated to repeat the assay using cynomolgus PTK7. The antibodies displayed a wide range of affinities for recombinant human PTK7 (Table 10; “PF”: poor fit, “NB”: no detectable binding). For example, eleven antibodies had KD <10 nM while eleven had KD> 25 nM.Table 10. Recombinant Human and Cynomolgus PTK7 Binding Kinetics

[0395] The binding kinetics of the second set of antibodies (n = 12) to human and cynomolgus recombinant PTK7 was also characterized using the Octet® BLI platform as described above. The data show that this set of antibodies displayed a wide range of affinities for recombinant human PTK7 (Table 11). For example, five antibodies had KD <1 nM, tw o antibodies had KD <10 nM, and five had KD > 10 nM.Table 11. Recombinant Human and Cynomolgus PTK7 Binding Kinetics

[0396] The above data show that unlike control antibody OTI2E7, most of the new antibodies identified herein were able to bind to both human and cynomolgus PTK7. This crossspecies binding feature is highly advantageous because it would allow these antibodies to be studied in non-human primates in pre-clinical toxicology studies.SEQUENCES

[0397] The table below shows sequences described herein (SEQ: SEQ ID NO).

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A conj ugate of the F ormula (XX) :Formula (XX) or a pharmaceutically acceptable salt thereof, wherein;L is a Targeting Unit, wherein the Targeting Unit is an anti-PTK7 antibody or an antigen-binding portion thereof;D is a Drug unit;Y1is absent or selected from -O-T1and -NH-T2;T1is a sugar cleavable unit;T2is peptide cleavable unit;51is selected from: (i) an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkydene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(O)2-, - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, - C(O)O-, -S-, — S(O)~ , — S(O)2— , 5- to 6-membered heterocyclene, or -P(O)(R20)2-; (ii) optionally substituted C3-C30 alkenylene, wherein one or more alkenylene units of the C3-C30 alkenylene are optionally and independently replaced by -N(R20)-, -N(R20)C(O)-, - C(O)N(R20)-, -N(R20)S(O)2-, - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, -C(O)O-, -S-, -S(O)-, — S(O)2— , or -P(O)(R20)2; (iii) one or more amino acid(s); (iv) one or more N-substituted amino acid(s); (v) optionally substituted polyether; (vi) optionally substituted C3-C10 carbocyclene; (vii) optionally substituted 5- to 10-membered heterocyclene;52is selected from an optionally substituted C1-C30 alkyd ene wherein one or more alkydene units of the C1-C30 alky lene are optionally and independently replaced by -N(R20)-, - N(R20)C(O)-, -C(O)N(R20)-, -N(R20)S(O)2-, - S(O)2N(R20)-, -O-, -C(O)-, -OC(O)-, - C(O)O-, -S-, — S(O)~ , — S(O)2— , 5- to 6-membered heterocyclene. or -P(O)(R20)2-;53is selected from a spacer, wherein S3is present or absent; wherein the optional substituents on M2, K1, S1, S2, and S3, are independently selected at each occurrence from:(i) halogen. -OR30, -N(R30)2, -SR30, -N(R30)2, -C(O)R30, -C(O)N(R30)2, - N(R30)C(O)R30. -C(O)OR30, -OC(O)R30. -S(O)R30, -S(O)2R30. -O- S(O)2OR30, -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =S, =N(R30), and -CN;(ii) Ci-10 alkyl, C2-10 alkenyl, C2-10 alkynyl, each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, -N(R30)2, -C(O)R30, - C(O)N(R30)2, -N(R30)C(O)R30, -C(O)OR30, -OC(O)R30, -S(O)R30, -S(O)2R30, -O-S(O)2OR30. -P(O)(OR30)2, -OP(O)(OR30)2, -NO2, =0, =S, =N(R30), -CN, C3-10 carbocycle and 3- to 10-membered heterocycle; and(iii) C3-10 carbocycle and 3- to 10-membered heterocycle each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, -SR30, - N(R30)2, -C(O)R30, -C(O)N(R30)2, -N(R30)C(O)R30-C(O)OR30, -OC(O)R30, -S(O)R30, - S(O)2R30, -P(O)(OR30)2, -OP(0)(OR30)2. -NO2, =0, =S, =N(R30), -CN, Ci-6alkyl. C2-6 alkenyl, and C2-6 alkynyl;M2is a connector unit;K1is selected from:(i) a peptide unit,(ii) an oligosaccharide; and(iii) a polyether; each R20is independently selected from hydrogen; and Ci-6 alky l, C2-6 alkenyl, C2-6 alkynyl, C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen. -OH. -CN. -NO2, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl, -O-Ci-10 alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle; and each R30is independently selected from hydrogen; and C1-6 alkyl, C2-6 alkenyl, C2-6 alky nyl, C3-12 carbocycle, and 3- to 12-membered heterocycle, each of which is optionally substituted with one or more substituents independently selected from halogen. -OH. -CN. -NO2, -NH2, - N(CI-6 alkyl)2, C1-10 alkyl, -C1-10 haloalkyl, -O-Ci-10 alkyl, oxo, C3-12 carbocycle, and 3- to 12- membered heterocycle.

2. The conjugate or salt of claim 1, wherein Formula (XX) is represented byFormula (A) or a pharmaceutically acceptable salt thereof.

3. The conjugate or salt of claim 1 or claim 2, wherein S1is selected from: (i) an optionally substituted C1-C30 alky lene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -N(H)C(O)-.

4. The conjugate or salt of any one of claims 1 to 3, wherein S1is selected from -NH-C(O)- Ci-Ce alkylene-NH-C(O)-Ci-Cs alkylene-NH-C(O)-Ci-Ce alkydene-.

5. The conjugate or salt of any one of claims 1 to 4, wherein S1is selected from -NH-C(O)- Ci-Ce alkylene-NH-C(O)-Ci-Cs alkylene-NH-C(O)-Ci-C6 alkylene-, and wherein S2is bound to one of the alkylene.

6. The conjugate or salt of any one of claims 1 to 5, wherein S1is7. The conjugate or salt of any one of claims 1 to 6, wherein S1is selected from8. The conjugate or salt of any one of claims 1 to 7, wherein S2is selected from an optionally substituted C1-C30 alkylene wherein one or more alkylene units of the C1-C30 alkylene are optionally and independently replaced by -C(O)-.

9. The conjugate or salt of any one of claims 1 to 8, wherein S2is selected from an optionally substituted Ci-Cg alkylene wherein one or more alkylene units of the Ci-Cg alkylene are optionally and independently replaced by -C(O)-.

10. The conjugate or salt of any one of claims 1 to 9, wherein S2is11. The conjugate or salt of any one of claims 1 to 6 or 8 to 10, wherein S^S^K1is12. The conjugate or salt of any one of claims 1 to 11. wherein S1-S2-I<1is13. The conjugate or salt of claim 2, wherein Formula (A) is represented byor a pharmaceutically acceptable salt thereof.

14. The conjugate or salt of any one of claims 1 to 13, wherein the sugar cleavable unit of T1includes a sugar.

15. The conjugate or salt of any one of claims 1 to 14. wherein the sugar is glucuronide.Cty AH16. The conjugate or salt of any one of claims 1 to 15. wherein Y1is OHz17. The conjugate or salt of any one of claims 1 to 15, wherein the peptide unit of T2includes one or more amino acids selected from a group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, sarcosine, serine, threonine, tryptophan, tyrosine, valine, citrulline, and |3-Alanine.

18. The conjugate or salt of any one of claims 1 to 15, wherein the peptide unit of T2includes a dipeptide or tripeptide.

19. The conjugate or salt of any one of claims 1 to 15, 17, or 18, wherein the peptide unit of T2includes a dipeptide.

20. The conjugate or salt of claim 18 or claim 19, wherein the dipeptide is selected from Val- Cit, Vai -Ala and Phe-Lys.

21. The conjugate or salt of any one of claims 1 to 15 or 17 to 20, wherein the peptide unit of T2includes a capping moiety.O22. The conjugate or salt of claim 21, wherein the capping moiety is23. The conjugate or salt of any one of claims 1 to 15 or 17 to 22, wherein Y1is24. The conjugate or salt of any one of claims 1 to 13, wherein Y1is absent.

25. The conjugate or salt of any one of claims 1 to 24, wherein each K1is selected from a peptide unit.

26. The conjugate or salt of any one of claims 1 to 25, wherein the peptide unit of K1has 1 to 50 amino acids.

27. The conjugate or salt of claim 26, wherein the amino acids of K1is selected from the group consisting of alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, sarcosine, serine, threonine, tryptophan, tyrosine, valine, citrulline, and P-Alanine.

28. The conjugate or salt of claim 26 or claim 27, wherein the amino acids of K1is selected from the group consisting of glycine, sarcosine, proline, serine, and P-Alanine.

29. The conjugate or salt of any one of claims 1 to 26, wherein the peptide unit of K1has a terminus unit.

30. The conjugate or salt of any one of claims 1 to 29. wherein K1is selected from, wherein the terminus unit is represented by R6. and each j is selected from 1 to 30.

31. The conjugate or salt of any one of claims 1 to 30, wherein K1is selected from, wherein the terminus unit is represented by R6. and each j is selected from 1 to 30.

32. The conjugate or salt of any one of claims 1 to 31, wherein K1is selected from, wherein the terminus unit is represented by R6, and each j is selected from 1 to 30.

33. The conjugate or salt of any one of claims 1 to 32, wherein K1is selected from34. The conjugate or salt of any one of claims 1 to 33, wherein K1is selected fromselected from 3 to 20.

35. The conjugate or salt of any one of claims 1 to 34. wherein K1is selected from, wherein j is selected from 5 to 15.

36. The conjugate or salt of any one of claims 1 to 34, wherein K1is selected from , wherein j is selected from 3 to 8. salt of any one of claims 1 to 34, wherein K1is selected from, wherein j is selected from 3 to 8.

38. The conjugate or salt of any one of claims 30 to 37, wherein R6is selected from -OR7and -NHR7, wherein R7is selected from hydrogen; Ci-io alkyl, C2-10 alkenyl, C2-10 alkynyl, each of which is optionally substituted with one or more substituents independently selected from halogen, -OR30, - OC(O)R30. -S(O)=N(R30), -CN, C 3-10 carbocycle and 3- to 10-membered heterocycle.

39. The conjugate or salt of any one of claims 30 to 38, wherein R6is selected from -OH, -40. The conjugate or salt of any one of claims 30 to 39, wherein R6is -OH.

41. The conjugate or salt of any one of claims 30 to 39, wherein R6is -NH2.

42. The conjugate or salt of any one of claims 30 to 39, wherein R6is43. The conjugate or salt of any one of claims 1 to 30. wherein K1is selected from44. The conjugate or salt of any one of claims 1 to 30 or 43, wherein K1is selected from45. The conjugate or salt of any one of claims 1 to 30, 43, or 44, wherein K1is46. The conjugate or salt of any one of claims 1 to 30 or 43. wherein K1is selected from47. The conjugate or salt of any one of claims 1 to 30, 43, 44, or 46, wherein K1is49. The conjugate or salt of any one of claims 1 to 30 or 43, wherein K1is selected from50. The conjugate or salt of any one of claims 1 to 30, 43, or 49, wherein K1is r salt of any one of claims 1 to 30, 43, 44, or 49, wherein K1is52. The conjugate or salt of any one of claims 1 to 30 or 43, wherein K1is selected from53. The conjugate or salt of any one of claims 1 to 30.

43. or 52, wherein K1is54. The conjugate or salt of any one of claims 1 to 30, 43, 44, or 52, wherein K1isThe conjugate or salt of any one of claims 1 to 30 or 43, wherein K1is56. The conjugate or salt of any one of claims 1 to 30, 43, or 44, wherein K1is57. The conjugate or salt of any one of claims 1 to 30, 43, or 44, wherein K1is58. The conjugate or salt of any one of claims 1 to 30 or 43, wherein K1is59. The conjugate or salt of any one of claims 1 to 30.

43. or 44, wherein K.1is60. The conjugate or salt of any one of claims 1 to 30 or 43. wherein K1is61. The conjugate or salt of any one of claims 1 to 24. wherein each K1is selected from: an oligosaccharide.

62. The conjugate or salt of any one of claims 1 to 24 or 61, wherein each K1is selected from:, wherein k is selected from 2 to 10.

63. The conjugate or salt of claim 62, wherein each K1is selected from:

64. The conjugate or salt of any one of claims 1 to 63, wherein M2is selected from65. The conjugate or salt of any one of claims 1 to 64, wherein M2is selected from66. The conjugate or salt of any one of claims 1 to 64. wherein M2is selected from67. The conjugate or salt of any one of claims 1 to 64 or 66, wherein68. The conjugate or salt of any one of claims 1 to 64 or 66, wherein69. The conjugate or salt of any one of claims 1 to 64 or 66, wherein M2is70. The conjugate or salt of any one of claims 1 to 69, wherein L is an anti-PTK7 antibody or an antigen-binding portion thereof.

71. The conjugate or salt of any one of claims 1 to 70, wherein the antibody or portion thereof comprises a heavy chain CDR (HCDR) 1-3 and a light chain CDR (LCDR) 1-3 comprising SEQ ID NOs:

151. 157, 161. 164, 167. and 170. respectively.

72. The conjugate or salt of claim 71, wherein the antibody or portion thereof comprises a heavy chain variable domain (VH) and a light chain variable domain (VL) comprising SEQ ID NOs:76 and 75, respectively.

73. The conjugate or salt of claim 71, wherein the antibody or portion thereof comprises a VH comprising SEQ ID NOs: 154, 155, and 161, and a VL comprising SEQ ID NOs: 163, 166, and 170.

74. The conjugate or salt of claim 72, wherein the antibody or portion thereof is humanized.

75. The conjugate or salt of claim 74, wherein the VH comprises framework regions derived from a human IGHV 1-46*01 germline gene.

76. The conjugate or salt of claim 75, wherein the VH comprises one or more back mutations selected from Y91F, R71V, V78A, M48I, M69L, and V20L, wherein the numbering is according to SEQ ID NO: 172.

77. The conjugate or salt of claim 74, wherein the VL comprises framework regions derived from a human IGKV1D-16*O1 germline gene.

78. The conjugate or salt of claim 77, wherein the VL comprises one or more back mutations selected from I21L, Y36L, A43T, S46R, G66R, T69S, and F71Y. wherein the numbering is according to SEQ ID NO: 183.

79. The conjugate or salt of claim 74, wherein a) the VH comprises any one of SEQ ID NOs: 172-182, 193, 196, and 197, or an amino acid sequence at least 95% identical thereto; b) the VL comprises any one of SEQ ID NOs: 183-192, 194, and 195, or an amino acid sequence at least 95% identical thereto; or c) a) and b).

80. The conjugate or salt of claim 79, wherein the VH and the VL compriseSEQ ID NOs: 178 and 188, respectively,SEQ ID NOs: 193 and 188. respectively, orSEQ ID NOs: 173 and 188, respectively.

81. The conjugate or salt of any one of claims 71 to 80, wherein the antibody comprises a human IgGl constant region.

82. The conjugate or salt of claim 81, wherein the human IgGl constant region comprises SEQ ID NO:201, optionally without the C-terminal lysine.

83. The conjugate or salt of any one of claims 71 to 81, wherein the antibody comprises a human light chain constant region that comprises SEQ ID NO: 199.

84. The conjugate or salt of any one of claims 1 to 70, wherein the antibody or portion thereof comprising a heavy chain that comprises the amino acid sequences of SEQ ID NOs: 193 and 201, optionally without the C-terminal lysine, and a light chain that comprises the amino acid sequences of SEQ ID NOs: 188 and 199.

85. The conjugate or salt of any one of claims 1 to 70, wherein the antibody or portion thereof comprises a) HCDR1-3 and LCDR1-3 comprising SEQ ID NOs:

204. 209, 213. 216, 219, and 222. respectively; b) VH and VL comprising SEQ ID NOs: 112 and 111, respectively; or c) an HC comprising SEQ ID NOs: 112 and 201, optionally without the C-terminal lysine, and an LC comprising SEQ ID NOs: 111 and 199.

86. The conjugate or salt of any one of claims 1 to 70, wherein the antibody or portion thereof comprises a) HCDR1-3 and LCDR1-3 comprising SEQ ID NOs:226, 231, 235, 238, 241, and 244, respectively; b) VH and VL comprising SEQ ID NOs: 128 and 127, respectively; or c) an HC comprising SEQ ID NOs: 128 and 201, optionally without the C-terminal lysine, and an LC comprising SEQ ID NOs: 127 and 199.

87. The conjugate or salt of any one of claims 1 to 70, wherein the antibody or portion thereof comprises a heavy chain variable domain (VH) and a light chain variable domain (VL), herein the VH and the VL comprise:SEQ ID NOs: 148 and 147, respectively;SEQ ID NOs:24 and 23, respectively;SEQ ID NOs: 36 and 35, respectively;SEQ ID NOs:4 and 3, respectively;SEQ ID NOs: 10 and 9, respectively;SEQ ID NOs: 16 and 15, respectively;SEQ ID NOs: 18 and 17, respectively;SEQ ID NOs:20 and 19, respectively; SEQ ID NOs:22 and 21, respectively; SEQ ID NOs:26 and 25, respectively; SEQ ID NOs:28 and 27, respectively; SEQ ID NOs:30 and 29, respectively;SEQ ID NOs: 32 and 31, respectively;SEQ ID NOs:34 and 33, respectively; SEQ ID NOs:38 and 37, respectively; SEQ ID NOs:40 and 39, respectively; SEQ ID N0s:2 and 1, respectively;SEQ ID N0s:6 and 5, respectively;SEQ ID N0s:8 and 7, respectively;SEQ ID NOs: 12 and 11, respectively; SEQ ID NOs: 14 and 13. respectively; SEQ ID NOs:42 and 41, respectively; SEQ ID NOs:44 and 43, respectively; SEQ ID NOs: 52 and 51, respectively; SEQ ID NOs: 54 and 53, respectively; SEQ ID NOs: 56 and 55, respectively; SEQ ID NOs:46 and 45, respectively; SEQ ID NOs: 48 and 47, respectively; SEQ ID NOs: 50 and 49, respectively; SEQ ID NOs: 82 and 81. respectively; SEQ ID NOs: 80 and 79, respectively; SEQ ID NOs: 58 and 57, respectively; SEQ ID NOs: 60 and 59, respectively; SEQ ID NOs: 62 and 61, respectively; SEQ ID NOs: 64 and 63, respectively; SEQ ID NOs: 66 and 65, respectively; SEQ ID NOs: 68 and 67, respectively; SEQ ID NOs: 70 and 69, respectively;SEQ ID NOs:72 and 71, respectively; SEQ ID NOs: 74 and 73, respectively; SEQ ID NOs: 76 and 75, respectively; SEQ ID NOs:78 and 77, respectively;SEQ ID NOs: 112 and 11 1, respectively;SEQ ID NOs: 102 and 101, respectively;SEQ ID NOs: 104 and 103, respectively;SEQ ID NOs: 106 and 105. respectively;SEQ ID NOs: 108 and 107. respectively;SEQ ID NOs: 110 and 109, respectively;SEQ ID NOs: 84 and 83, respectively;SEQ ID NOs: 86 and 85, respectively;SEQ ID NOs: 88 and 87, respectively;SEQ ID NOs: 90 and 89, respectively;SEQ ID NOs: 92 and 91, respectively;SEQ ID NOs: 94 and 93, respectively;SEQ ID NOs: 96 and 95, respectively;SEQ ID NOs: 98 and 97. respectively;SEQ ID NOs: 100 and 99, respectively;SEQ ID NOs: 114 and 113, respectively;SEQ ID NOs: 120 and 119. respectively;SEQ ID NOs: 128 and 127. respectively;SEQ ID NOs: 130 and 129, respectively;SEQ ID NOs: 132 and 131, respectively;SEQ ID NOs: 134 and 133, respectively;SEQ ID NOs: 136 and 135. respectively;SEQ ID NOs: 138 and 137. respectively;SEQ ID NOs: 140 and 139, respectively;SEQ ID NOs: 142 and 141, respectively;SEQ ID NOs: 144 and 143. respectively;SEQ ID NOs: 146 and 145. respectively;SEQ ID NOs: 116 and 115, respectively;SEQ ID NOs: 118 and 117, respectively;SEQ ID NOs: 122 and 121, respectively;SEQ ID NOs: 124 and 123. respectively;SEQ ID NOs: 126 and 125, respectively; orSEQ ID NOs: 193 and 188, respectively.

88. The conjugate or salt of any one of claims 1 to 70, wherein the antibody or portion thereof comprises a heavy chain variable domain (VH) and a light chain variable domain (VL), wherein the VH and the VL comprise:SEQ ID NOs: 148 and 147. respectively;SEQ ID NOs: 10 and 9, respectively;SEQ ID NOs: 16 and 15, respectively;SEQ ID NOs: 18 and 17, respectively;SEQ ID NOs: 20 and 19, respectively;SEQ ID NOs:26 and 25, respectively;SEQ ID NOs: 30 and 29, respectively;SEQ ID NOs: 112 and 111, respectively;SEQ ID NOs: 110 and 109, respectively;SEQ ID NOs: 86 and 85, respectively;SEQ ID NOs: 128 and 127. respectively;SEQ ID NOs: 122 and 121, respectively; orSEQ ID NOs: 193 and 188, respectively.

89. The conjugate or salt of claim 87 or claim 88, wherein the antibody comprises a human IgGl constant region.

90. The conjugate or salt of any one of claims 87 to 89, wherein the human IgGl constant region comprises SEQ ID NO:201, optionally without the C-terminal lysine.

91. The conjugate or salt of any one of claims 87 to 89, wherein the antibody comprises a human light chain constant region that comprises SEQ ID NO: 199.

92. The conjugate or salt of any one of claims 1 to 91. wherein the PTK.7 antibody is optionally without the C-terminal lysine.

93. The conjugate or salt of any one of claims 1 to 92, wherein D is selected from a cytotoxic agent, an immune modulatory agent, a nucleic acid, a growth inhibitory agent, a PROTAC, a toxin, a radioactive isotope and a chelating ligand.

94. The conjugate or salt of any one of claims 1 to 93, wherein D is selected from a cytotoxic agent and an immune modulatory agent.

95. The conjugate or salt of any one of claims 1 to 93, wherein D is selected from a cytotoxic agent.

96. The conjugate or salt of any one of claims 1 to 93, wherein D is selected from an immune modulatory agent.

97. The conjugate or salt of any one of claims 1 to 93, wherein D is selected from exatecan, MMAE, and MMAF.

98. The conjugate or salt of any one of claims 1 to 93, wherein D is exatecan.

99. The conjugate or salt of any one of claims 1 to 93, wherein D is MMAE.

100. A conjugate selected from Table AA-1 and Table AA-2.

101. A conjugate selected from Table AA-1.

102. The conjugate or salt of any one of claims 1 to 101, having a DAR (drug to antibody ratio) of about 1 to about 10.

103. The conjugate or salt of any one of claims 1 to 102, having a DAR of about 2 to about 8.

104. The conjugate or salt of any one of claims 1 to 103, having a DAR of about 3 to about 8.

105. The conjugate or salt of any one of claims 1 to 101, having a DAR of about 2, about 3, about 4, about 5, about 6, about 7, or about 8.

106. The conjugate or salt of any one of claims 1 to 101, having a DAR of about 8.

107. A pharmaceutical composition comprising a conjugate of any one of claims 1 to 106 and a pharmaceutically acceptable excipient.

108. A method of treating a subject with a disease or disorder, comprising administering to the subject in need thereof a conjugate of any one of claims 1 to 106 or a pharmaceutical composition of claim 107.

109. The method of claim 108, wherein the disease or disorder is a cancer.

110. A method of treating a subject with a cancer, comprising administering to the subject in need thereof a conjugate of any one of claims 1 to 106 or a pharmaceutical composition of claim 107.

111. A method of treating a subject with a PTK7-positive cancer, comprising administering to the subject in need thereof a conjugate of any one of claims 1 to 106 or a pharmaceutical composition of claim 107.

112. The method of any one of claims 109 to 111, wherein the cancer is selected from: melanoma, skin basal cell cancer, glioblastoma, glioma, gliosarcoma, astrocytoma, meningioma, neuroblastoma, adrenocortical cancer, head and neck cancer (e.g., cancer of the head, neck, nasal cavity, paranasal sinuses, nasopharynx, oral cavity, oropharynx, larynx, hypopharynx, and / or salivary glands, and paragangliomas), oral cancer, salivary' gland cancer, nasopharyngeal cancer, breast cancer (e.g., triple negative breast cancer), lung cancer (e.g., non-small cell lung cancer (NSCLC), small cell lung cancer, or squamous cell lung cancer), esophageal cancer, gastroesophageal junction cancer, gastric cancer, gastrointestinal cancer, primary peritoneal cancer, liver cancer, hepatocellular carcinoma, gallbladder cancer, biliary tract cancer, cholangiocarcinoma, colon cancer, rectal cancer, colorectal carcinoma, ovarian cancer, fallopian tube cancer, bladder cancer, upper urinary' tract cancer, urothelial cancer, renal cell carcinoma, kidney cancer, genitourinary cancer, cervical cancer, testicular cancer, prostate cancer,fibrosarcoma, liposarcoma, rhabdomyosarcoma (e.g., embryonal rhabdomyosarcoma), leiomyosarcoma, neurofibrosarcoma, synovial sarcoma, liposarcoma, alveolar soft part sarcoma, osteosarcoma, histiocytoma (e.g., malignant fibrous histiocytoma), pancreatic cancer, endometrial cancer, cancer of the appendix, thyroid cancer, advanced Merkel cell cancer, multiple myeloma, sarcomas, choriocarcinoma, leukemia (e.g., erythroleukemia, acute lymphoblastic leukemia, acute monocytic leukemia, acute promyelocytic leukemia, acute myeloid leukemia, acute myelogenous leukemia, chronic myeloid leukemia, chronic myelogenous leukemia, chronic lymphocytic leukemia, acute lymphoblastic leukemia, or mast cell leukemia), lymphoma (e.g., small lymphocytic lymphoma, Burkitt’s lymphoma, Hodgkin’s lymphoma, non-Hodgkin’s lymphoma, diffuse large B cell lymphoma, lymphoplasmacytoid lymphoma, mucosa-associated lymphoid tissue lymphoma, mantle cell lymphoma, T-cell anaplastic large cell lymphoma, follicular lymphoma, monocytic lymphoma, or HTLV- associated T cell leukemia / lymphoma), or mesothelioma. In certain embodiments, the cancer is selected from the group consisting of head and neck cancer, bone cancer (e.g., osteosarcoma), Ew ing sarcoma, squamous cell carcinoma, lung cancer (e.g., non-small cell lung cancer or small cell lung cancer), kidney cancer, urethral cancer, colorectal cancer, prostate cancer, glioblastoma multiforme, ovarian cancer, cervical cancer, pancreatic cancer, breast cancer (e.g., triple negative breast cancer), melanoma, liver cancer, bladder cancer, stomach cancer, esophageal cancer, and chronic myelogenous leukemia. In particular embodiments, the cancer is selected from the group consisting of head and neck cancer, non-small cell lung cancer, esophageal cancer, gastric cancer, hepatic cancer, pancreatic cancer, colorectal cancer, breast cancer, endometrial cancer, ovarian cancer, soft-tissue sarcoma, bladder cancer, prostate cancer, renal cancer, and melanoma.

113. The method of any one of claims 109 to 112, wherein the cancer is selected from cell lymphoma, non-small cell lung cancer, large-cell lung cancer, breast cancer, and small-cell lung cancer.

114. The method of any one of claims 109 to 112, wherein the cancer is cell lymphoma.

115. The method of any one of claims 109 to 112, wherein the cancer is non-small cell lung cancer.

116. The method of any one of claims 109 to 112, wherein the cancer is large-cell lung cancer.

117. The method of any one of claims 109 to 112, wherein the cancer is breast cancer.

118. The method of any one of claims 109 to 112, wherein the cancer is small-cell lung cancer.

119. Use of a conjugate, for treating a subject with a disease or disorder, comprising administering to the subject in need thereof a conjugate of any one of claims 1 to 106 or a pharmaceutical composition of claim 107.

120. The use of claim 119, wherein the disease or disorder is cancer.

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