Methylene Carbamate Linkers for use with Targeted-Drug Conjugates

Abstract

The present invention provides Ligand-Drug Conjugates and Drug-Linker Compounds comprising a methylene carbamate unit. The invention provides inter alia, Ligand-Drug Conjugates, wherein the Ligand-Drug Conjugate is comprised of a Self-immolative Assembly Unit having a methylene carbamate unit for conjugation of a drug to a targeting ligand, methods of preparing and using them, and intermediates thereof. The Ligand-Drug Conjugates of the present invention are stable in circulation, yet capable of inflicting cell death once free drug is released from a Conjugate in the vicinity or within tumor cells.

1 - 49 . (canceled) 
     
     
         50 . A Drug-Linker compound, wherein the compound comprises a Drug Unit and a Linker Unit, wherein the Linker Unit comprises a Self-Immolative Assembly Unit having a methylene carbamate unit and an activateable self-immolative moiety wherein the Drug Unit is covalently attached to the methylene carbamate unit,
 wherein the Drug-Linker compound has the structure of formula V:   
       
         
           
           
               
               
           
         
         or a pharmaceutically acceptable salt thereof; wherein 
         D is a Drug Unit incorporating a free drug having a hydroxyl, thiol, amine or amide functional group, wherein the functional group has been incorporated into the indicated methylene carbamate unit; 
         T* is the oxygen, sulfur or optionally substituted nitrogen heteroatom from said functional group; 
         R, R 1  and R 2  independently are hydrogen, optionally substituted C 1 -C 6  alkyl, optionally substituted C 6-14  aryl, or optionally substituted C-linked heteroaryl having from 3 to 8 carbon atom ring members and one to four heteroatom ring members independently selected from the group consisting of N, O, P and S, or 
         wherein R is a Basic Unit wherein the basic functional group of the Basic Unit is an amine or a nitrogen-containing 3, 4, 5, or 6 membered heterocycle, optionally substituted, wherein the heterocycle is C-linked or N-linked, or the basic functional group of the Basic Unit is —N(R op ) 2 , wherein each R op  is independently selected from the group consisting of hydrogen and C 1 -C 6  alkyl or each R op  is methyl; 
         X is an activateable self-immolative moiety; 
         Z′ is a Stretcher Unit precursor to a Stretcher Unit (Z) and comprises a functional group that provides for covalent attachment of a Ligand Unit to Z; 
         B is an optional Branching Unit that is present when t is greater than 1 and is absent when tis 1; 
         A is an optional Connector Unit; and 
         the subscript t ranges from 1 to 4. 
       
     
     
         51 . The Drug-Linker compound of  claim 50 , wherein D is a Drug Unit corresponding to a drug having a hydroxyl functional group that has been incorporated into the methylene carbamate unit of the Self-immolative Assembly Unit; and T* is the oxygen atom from that functional group. 
     
     
         52 . The Drug-Linker compound of  claim 50 , wherein X is —Y(W)—, wherein —Y(W)— is represented by the structure of: 
       
         
           
           
               
               
           
         
         wherein the wavy bond adjacent to the nitrogen of Y indicates covalent attachment to Z′, A or B, depending on the presence or absence of A and/or B, and the hash mark (#) indicates covalent attachment of the benzylic carbon of Y to the methylene carbamate unit. 
       
     
     
         53 . The Drug-Linker compound of  claim 50  or  51 , wherein X is —W—Y, wherein —W—Y— is represented by the structure of: 
       
         
           
           
               
               
           
         
         wherein the wavy bond adjacent to the nitrogen heteroatom of W indicates covalent attachment of W to Z′, A or B, depending on the presence or absence of A and/or B and the hash mark (#) indicates covalent attachment of the benzylic carbon of Y to the methylene carbamate unit. 
       
     
     
         54 . The Drug-Linker compound of  claim 50 , wherein Z′ comprises a maleimide moiety. 
     
     
         55 . The Drug-Linker compound of  claim 54 , wherein Z′ has the formula: 
       
         
           
           
               
               
           
         
         wherein the wavy line adjacent to the carbonyl indicates covalent attachment of Z′ to A, B or X, depending on the presence or absence of A and/or B. 
       
     
     
         56 . The Drug-Linker compound of  claim 50 , wherein A is present and has the formula: 
       
         
           
           
               
               
           
         
       
     
     
         57 . The Drug-Linker compound of  claim 50 , wherein B is absent and t is 1. 
     
     
         58 . The Drug-Linker compound of  claim 50 , wherein B is present and t is 2. 
     
     
         59 - 61 . (canceled) 
     
     
         62 . The Drug-Linker compound of  claim 50 , wherein the free drug binds to FKBP to inhibit mTOR or calcineurin effector function. 
     
     
         63 . The Drug-Linker compound of  claim 62 , wherein the FKBP binding compound is everolimus, tacrolimus or sirolimus. 
     
     
         64 . The Drug-Linker compound of  claim 62 , wherein the compound or composition has the structure of: 
       
         
           
           
               
               
           
         
         or a pharmaceutically acceptable salt thereof, 
         wherein R is hydrogen, ethyl or —CH 2 CH 2 N(CH 3 ) 2 . 
       
     
     
         65 . The Drug-Linker compound of  claim 62 , wherein the compound has the structure of: 
       
         
           
           
               
               
           
         
         or a pharmaceutically acceptable salt thereof, 
         wherein R is hydrogen, ethyl or —CH 2 CH 2 N(CH 3 ) 2 . 
       
     
     
         66 . The Drug-Linker compound of  claim 62 , wherein the compound has the structure of: 
       
         
           
           
               
               
           
         
         or a pharmaceutically acceptable salt thereof, 
         wherein R is hydrogen, ethyl or —CH 2 CH 2 N(CH 3 ) 2 . 
       
     
     
         67 . The Drug-Linker compound of  claim 50 , wherein the Drug Unit incorporates an auristatin free drug having a hydroxyl functional group, wherein the functional group has been incorporated into the indicated methylene carbamate unit, wherein the compound binds to tubulin to disrupt tubulin function. 
     
     
         68 . The Drug-Linker compound of  claim 67 , wherein the auristatin is MMAE or auristatin T. 
     
     
         69 . (canceled) 
     
     
         70 . A method of preparing a Drug-Linker Compound of  claim 50 , wherein the Drug-Linker Compound has the structure of: 
       
         
           
           
               
               
           
         
         said method comprising: 
         contacting a modified free drug having the structure of: 
       
       
         
           
           
               
               
           
         
         with an intermediate linker moiety represented by: Z′-A-X′—OH, 
         under conditions sufficient for providing the indicated MAC unit through Curtius rearrangement, 
         wherein D is a Drug Unit that incorporates a free drug having a hydroxyl functional group, wherein the functional group has been incorporated into the MAC Unit, the oxygen heteroatom from which is designated by O*; 
         Z′ is a stretcher unit precursor to a Stretcher Unit (Z) in a Ligand-Drug Conjugate and comprises a functional group capable of conjugation to a targeting ligand; 
         A is an optional Connector Unit; 
         X is an activeatable self-immolative moiety; 
         X′ is a self-immolative moiety precursor to X and has a hydroxyl functional group that participates in the Curtius rearrangement; 
         R is hydrogen; and 
         R 1  is hydrogen, or C 1 -C 6  alkyl, C 6 -C 14  aryl or C-linked heteroaryl, optionally substituted with suitable protection as required. 
       
     
     
         71 . (canceled) 
     
     
         72 . A method of preparing a Drug-Linker Compound of  claim 50  wherein the Drug-Linker compound has the structure of: 
       
         
           
           
               
               
           
         
         said method comprising: 
         contacting a drug having a free hydroxyl functional group with a N-chloromethylamine having the structure of: 
       
       
         
           
           
               
               
           
         
         under conditions sufficient for substitution of the chorine atom with the oxygen heteroatom from said free drug functional group, 
         wherein 
         Z′ is a Stretcher Unit precursor to a Stretcher Unit (Z) of the Drug-Linker Compound and comprises a functional group for attachment of a targeting ligand; 
         A is an optional Connector Unit; 
         X is an activateable self-immolative moiety; 
         R is hydrogen, or C 1 -C 6  alkyl, C 6 -C 14  aryl or C-linked heteroaryl, optionally substituted with suitable protection; and 
         R 1  is hydrogen, or C 1 -C 6  alkyl, C 6 -C 14  aryl or C-linked heteroaryl, optionally substituted with suitable protection as required, 
         or R and R 1  together with the nitrogen and carbon atoms to which they are attached comprise a pyrrolodinyl or piperidinyl moiety. 
       
     
     
         73 . (canceled)