Monomethylvaline compounds capable of conjugation to ligands

Abstract

Auristatin peptides, including MeVal-Val-Dil-Dap-Norephedrine (MMAE) and MeVal-Val-Dil-Dap-Phe (MMAF), were prepared and attached to Ligands through various linkers, including maleimidocaproyl-val-cit-PAB. The resulting ligand drug conjugates were active in vitro and in vivo.

1 . (canceled) 
     
     
         2 . An antibody-drug conjugate having the formula: 
       
         
           
           
               
               
           
         
         or a pharmaceutically acceptable salt thereof, wherein: 
         Ab is an antibody, 
         A is a Stretcher unit, having the structure of 
       
       
         
           
           
               
               
           
         
         a is 1, 
         —W w — unit is a tetrapeptide; wherein each —W— unit is independently an Amino Acid unit having the formula denoted below in the square bracket: 
       
       
         
           
           
               
               
           
         
       
       wherein R 19  is hydrogen, methyl, isopropyl, isobutyl, sec-butyl, benzyl, p-hydroxybenzyl, —CH 2 OH, —CH(OH)CH 3 , —CH 2 CH 2 SCH 3 , —CH 2 CONH 2 , —CH 2 COOH, —CH 2 CH 2 CONH 2 , —CH 2 CH 2 COOH, —(CH 2 ) 3 NHC(═NH)NH 2 , —(CH 2 ) 3 NH 2 , —(CH 2 ) 3 NHCOCH 3 , —(CH 2 ) 3 NHCHO, —(CH 2 ) 4 NHC(═NH)NH 2 , —(CH 2 ) 4 NH 2 , —(CH 2 ) 4 NHCOCH 3 , —(CH 2 ) 4 NHCHO, —(CH 2 ) 3 NHCONH 2 , —(CH 2 ) 4 NHCONH 2 , —CH 2 CH 2 CH(OH)CH 2 NH 2 , 2-pyridylmethyl-, 3-pyridylmethyl-, 4-pyridylmethyl-, phenyl, cyclohexyl, 
       
         
           
           
               
               
           
         
         Y is a Spacer unit, 
         y is 0, 1, or 2, 
         D is a drug moiety, and 
         p ranges from 1 to about 20, and 
         wherein the Stretcher unit A is linked to the antibody via a sulfur atom on a cysteine residue of the antibody. 
       
     
     
         3 . The antibody-drug conjugate of  claim 2 , wherein Y is a self-immolative spacer. 
     
     
         4 . The antibody-drug conjugate of  claim 3 , wherein y is 1. 
     
     
         5 . The antibody-drug conjugate of  claim 4 , wherein p is about 3 to about 8. 
     
     
         6 . The antibody-drug conjugate of  claim 5 , wherein p is about 4. 
     
     
         7 . The antibody-drug conjugate of  claim 5 , wherein p is about 8. 
     
     
         8 . The antibody-drug conjugate of  claim 2 , wherein a substantial amount of the drug moiety is not cleaved from the antibody until the antibody-drug conjugate enters a cell with a cell-surface receptor specific for the antibody of the antibody-drug conjugate, and the drug moiety is cleaved from the antibody when the antibody-drug conjugate does enter the cell. 
     
     
         9 . The antibody-drug conjugate of  claim 2 , wherein the bioavailability of the antibody-drug conjugate or an intracellular metabolite of the antibody-drug conjugate in a patient is improved when compared to a drug compound comprising the drug moiety of the antibody-drug conjugate. 
     
     
         10 . The antibody-drug conjugate of  claim 2 , wherein the bioavailability of the antibody-drug conjugate or an intracellular metabolite of the antibody-drug conjugate in a patient is improved when compared to an analog of the antibody-drug conjugate not having the drug moiety. 
     
     
         11 . The antibody-drug conjugate of  claim 2 , wherein the drug moiety is intracellularly cleaved in a patient from the antibody of the antibody-drug conjugate or an intracellular metabolite of the antibody-drug conjugate. 
     
     
         12 . The antibody-drug conjugate of  claim 2 , wherein the antibody is a monoclonal antibody. 
     
     
         13 . A method of preparing an antibody-drug conjugate having the formula: 
       
         
           
           
               
               
           
         
         or a pharmaceutically acceptable salt thereof, wherein: 
         Ab is an antibody, 
         A is a Stretcher unit, having the structure of 
       
       
         
           
           
               
               
           
         
         a is 1, 
         —W w — unit is a tetrapeptide; wherein each —W— unit is independently an Amino Acid unit having the formula denoted below in the square bracket: 
       
       
         
           
           
               
               
           
         
       
       wherein R 19  is hydrogen, methyl, isopropyl, isobutyl, sec-butyl, benzyl, p-hydroxybenzyl, —CH 2 OH, —CH(OH)CH 3 , —CH 2 CH 2 SCH 3 , —CH 2 CONH 2 , —CH 2 COOH, —CH 2 CH 2 CONH 2 , —CH 2 CH 2 COOH, —(CH 2 ) 3 NHC(═NH)NH 2 , —(CH 2 ) 3 NH 2 , —(CH 2 ) 3 NHCOCH 3 , —(CH 2 ) 3 NHCHO, —(CH 2 ) 4 NHC(═NH)NH 2 , —(CH 2 ) 4 NH 2 , —(CH 2 ) 4 NHCOCH 3 , —(CH 2 ) 4 NHCHO, —(CH 2 ) 3 NHCONH 2 , —(CH 2 ) 4 NHCONH 2 , —CH 2 CH 2 CH(OH)CH 2 NH 2 , 2-pyridylmethyl-, 3-pyridylmethyl-, 4-pyridylmethyl-, phenyl, cyclohexyl, 
       
         
           
           
               
               
           
         
         Y is a Spacer unit, 
         y is 0, 1 or 2, 
         D is a drug moiety, and 
         p ranges from 1 to about 20, and 
         wherein the Stretcher unit A is covalently attached to the antibody via a sulfur atom on acystene residue of the antibody, 
         comprising conjugating a drug linker having the formula: 
       
       
         
           
           
               
               
           
         
         to the antibody Ab. 
       
     
     
         14 . The method of  claim 13 , wherein A has the structure of 
       
         
           
           
               
               
           
         
       
       and R 19  is hydrogen or benzyl. 
     
     
         15 . The method of  claim 14 , further comprising a step of partially or fully reducing cysteine disulfide residues of the antibody, and
 wherein the conjugation is achieved via a chemical reaction between the maleimide group of the drug linker and the reduced cysteine disulfide residues of the antibody.   
     
     
         16 . The method of  claim 14 , wherein Y in the antibody-drug conjugate is a self-immolative spacer. 
     
     
         17 . The method of  claim 14 , wherein y in the antibody-drug conjugate is 1. 
     
     
         18 . The method of  claim 14 , wherein p in the antibody-drug conjugate is about 3 to about 8. 
     
     
         19 . The method of  claim 18 , wherein p in the antibody-drug conjugate is about 4. 
     
     
         20 . The method of  claim 18 , wherein p in the antibody-drug conjugate is about 8. 
     
     
         21 . The method of  claim 14 , wherein the antibody in the antibody-drug conjugate is a monoclonal antibody.