Cytotoxic agents comprising new ansamitocin derivatives

Abstract

New ansamitocin derivatives bearing a linking group are disclosed. Also disclosed are methods for the synthesis of these new ansamitocin derivatives and methods for their linkage to cell-binding agents. The ansamitocin derivative-cell-binding agent conjugates are useful as therapeutic agents, which are delivered specifically to target cells and are cytotoxic. These conjugates display vastly improved therapeutic efficacy in animal tumor models compared to the previously described agents.

1 - 59 . (canceled) 
     
     
         60 . A compound represented by any one of compounds 6 to 26, or a pharmaceutically acceptable salt or solvate thereof: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         61 - 92 . (canceled) 
     
     
         93 . A method of inhibiting abnormal cell growth or treating a proliferative disorder, an autoimmune disorder, destructive bone disorder, infectious disease, viral disease, fibrotic disease, neurodegenerative disorder, pancreatitis or kidney disease in a mammal comprising administering to said mammal a therapeutically effective amount of a cell binding agent conjugate, or a pharmaceutically acceptable salt or solvate thereof, and, optionally, a chemotherapeutic agent, wherein the conjugate comprises a cell binding agent chemically linked to a derivatized maytansinol or maytansinol analog residue, and is represented by the following formula:
   (MayO-A-Y-L′) m -CB;
   wherein:
 MayO is a residue of maytansinol or maytansinol analog represented by MayOH; 
 A is an optional group selected from the group consisting of: C═O, C(═O)NR′, and C(═O)O, R′ is selected from the group consisting of: H, substituted or unsubstituted linear, branched, or cyclic alkyl, alkenyl or alkynyl, and substituted or unsubstituted aryl; 
 Y is an optional group selected from the group consisting of: a substituted or unsubstituted linear, branched, or cyclic alkyl, alkenyl or alkynyl, a substituted or unsubstituted aryl, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted arylalkyl, a substituted or unsubstituted heterocyclylalkyl group, an aziridine, and an epoxy group, wherein each of the alkyl, alkenyl, alkynyl, arylalkyl and heterocyclylalkyl groups is optionally interrupted by one or more groups selected from the group consisting of: a polyethylene glycol unit (OCH 2 CH 2 ) n , an aziridine group, an epoxy group, an amino group, an amido group, an ester group, an aryl group, a heterocyclic group, an amino acid, and a peptide, wherein n is an integer from 1 to 200; 
 L′ is a linker; 
 m is an integer from 1 to 20; and, 
 CB represents the cell binding agent; 
   provided that the conjugate does not comprise a N-methylalanine or N-methylcysteine moiety represented by the following formula:   
       
         
           
           
               
               
           
         
         directly connected to MayO-. 
       
     
     
         94 . The method of  claim 93 , wherein said second chemotherapeutic agent is administered to said mammal sequentially or consecutively. 
     
     
         95 . The method of  claim 93 , wherein the method is for treating a condition selected from cancer, rheumatoid arthritis, multiple sclerosis, graft versus host disease (GVHD), transplant rejection, lupus, myositis, infection, and immune deficiency. 
     
     
         96 . The method of  claim 93 , wherein the method is for treating a cancer. 
     
     
         97 . The method of  claim 96 , wherein the cancer is selected from breast cancer, colon cancer, brain cancer, prostate cancer, kidney cancer, pancreatic cancer, ovarian cancer, head and neck cancer, melanoma, colorectal cancer, gastric cancer, squamous cancer, small-cell lung cancer, non small-cell lung cancer, testicular cancer, Merkel cell carcinoma, glioblastoma, neuroblastoma, and cancers of lymphatic organs. 
     
     
         98 . The method of  claim 93 , wherein Y is an optional group selected from the group consisting of: C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, haloC 1-6 alkyl, C 1-6 alkyl having a halogen and a hydroxyl group on two adjacent carbon atoms, 
       
         
           
           
               
               
           
         
       
       —C 2-6 alkenyl-Ar—, —Ar—C 2-6 alkenyl-, —C 2-6 alkynyl-Ar—, —Ar—C 2-6 alkynyl-, —C 1-6 alkyl-Ar— having a halogen and a hydroxyl group on two adjacent carbon atoms of the C 1-6 alkyl, and —Ar—C 1-6 alkyl having a halogen and a hydroxyl group on two adjacent carbon atoms, wherein Ar is an optionally substituted aryl or an optionally substituted heterocyclyl and the alkenyl, alkynyl, alkyl in the groups represented by Y are optionally substituted. 
     
     
         99 . The method of  claim 93 , wherein -A-Y— is represented by one of the following formula: 
       
         
           
           
               
               
           
         
         wherein 
         n and n′ are each independently 0, 1, 2 or 3; 
         n″ is 1, 2 or 3; and 
         R c  for each occurrence is H, halogen, —NO 2 , C 1-4 alkyl, C 1-4 alkoxy, hydroxyC 1-4 alkyl, haloC 1-4 alkyl, —OH, —OC(═O)—C 1-4 alkyl, —OC(═O)—C 1-4 alkyl-NR a R b , —C 1-4 alkyl-COOH, wherein R a  and R b  are each independently H, C 1-4 alkyl, aminoC 1-4 alkyl or an amino protecting group, or R a  and R b  together with the nitrogen atom forms a heterocyclic ring having one or more heteratoms. 
       
     
     
         100 . The method of  claim 93 , wherein Y is represented by formula:
   —[Ar″] 0-1 —(CR 1 R 2 ) x —B—W-D-(CR 1 R 2 ) w ;
   wherein:   Ar″ is phenyl, —CH 2 -phenyl, heterocyclyl, or —CH 2 -heterocyclyl, optionally substituted with one to four groups selected from the group consisting of: alkyl, alkoxyl, halo, haloalkyl, alkoxy-haloalkyl, nitrile and nitro;   each R 1  and R 2  is independently hydrogen or C 1-4 alkyl;   B is NR″, O or absent;   W is an amino acid or a peptide comprising 2 to 8 amino acids, (OCH 2 CH 2 ) n  or absent;   D is CO, NR″ or absent;   R″ is selected from the group consisting of: H, substituted or unsubstituted linear, branched, or cyclic alkyl, alkenyl or alkynyl, and substituted or unsubstituted aryl;   x is an integer from 1 to 10;   w is 0 or an integer from 1 to 10; and   n is an integer from 1 to 200.   
     
     
         101 . The method of  claim 93 , wherein Y is represented by one of the following formula: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         102 . The method of  claim 93 , wherein: MayO is represented by the formula: 
       
         
           
           
               
               
           
         
       
       wherein:
 X′ 4 ═X′ 5  or OX′ 5 , and 
 X′, X′ 1 , X′ 2 , X′ 3 , and X′ 5  are the same or different and are selected from the group consisting of: R, C(═O)R, C(═O)NR 2 , and C(═O)OR, wherein: each R is independently selected from the group consisting of: H, substituted or unsubstituted linear, branched, or cyclic alkyl, alkenyl or alkynyl, and substituted or unsubstituted aryl; 
 Q is O or S; provided that at least one of X′, X′ 1 , X′ 2 , X′ 3 , X′ 5  represents a covalent bond between MayO and A or AY. 
 
     
     
         103 . The method of  claim 93 , wherein the conjugate is represented by formula:
   (MayO-A-Y-M′-BFCG) m -CB;
   or a pharmaceutically acceptable salt or solvate thereof, wherein:   BFCG is absent or the residue of a bifunctional crosslinking reagent comprising two linking groups, wherein one of the linking groups has reacted with M′ and the other linking group has reacted with the cell binding agent;   M′ is the residue of a linking group that together with one of the reacted linking groups of BFCG forms a thioether, a disulfide, a thioester, an amide, an imine, a —O-imine or a hydrazone moiety; and   BFCG is linked to the CB through a thioether, a disulfide, a thioester, an amide, an imine, a —O-imine or a hydrazone moiety.   
     
     
         104 . The method of  claim 103 , wherein BFCG comprises a moiety M″ connected to M′ and a moiety Z connected to CB, wherein M″ and Z are each independently selected from the group consisting of —C(═O)—, —C(═O)—NR e —, —C(═O)—O—, —O—C(═O)—, —C(═NH)—, —C(═NH)—NR e —, —S—, —NR e —, —NH—NR e —, 
       
         
           
           
               
               
           
         
       
       —C(═NR e )—, ═NNR e —, —CH 2 —C(═O)—, and —CH 2 —C(═O)—NR e —, wherein R e  is H, an alkyl, an alkenyl or an alkynyl. 
     
     
         105 . The method of  claim 104 , wherein M′-M″ is represented by a structural formula selected from the group consisting of: 
       
         
           
           
               
               
           
         
       
     
     
         106 . The method of  claim 103 , wherein —BFCG- is represented by formula:
   -M″-(CR 3 R 4 ) y -[Cy] 0 or 1 -C(O)—;
 
 
       wherein:
 M″ is 
 
       
         
           
           
               
               
           
         
         each R 3  and R 4  is independently hydrogen, methyl or —SO 3   − M + , wherein: M +  is H +  or a pharmaceutically acceptable cation; 
         Cy is a cycloalkyl or a phenyl optionally substituted with one to four groups selected from the group consisting of: alkyl, alkoxyl, halo, haloalkyl, alkoxy haloalkyl, nitrile and nitro; and y is 0 or an integer from 1 to 10. 
       
     
     
         107 . The method of  claim 103 , wherein —BFCG- is represented by formula:
   —S—(CR 3 R 4 ) y —C(O)—;
 
 wherein: 
 each R 3  and R 4  is independently hydrogen, methyl or —SO 3   − M + , wherein: M +  is H +  or a pharmaceutically acceptable cation; and, 
 y′ is an integer from 1 to 10. 
 
     
     
         108 . The method of  claim 103 , wherein BFCG comprises a self-immolative moiety. 
     
     
         109 . The method of  claim 104 , wherein BFCG is represented by the following formula: 
       
         
           
           
               
               
           
         
       
       wherein AA is an amino acid or a peptide comprising 2 to 8 amino acids and R 100  is H or an alkyl. 
     
     
         110 . The method of  claim 103 , wherein the BFCG is selected from the group consisting of: 
       
         
           
           
               
               
           
         
         wherein: 
         AA is Val-Cit, Phe-Lys or Val-Lys, 
         q is an integer from 1 to 5; 
         n is an integer from 1 to 20; and 
         M is H +  or a pharmaceutically acceptable cation. 
       
     
     
         111 . The method of  claim 93 , wherein the cell-binding agent binds to target cells selected from the group consisting of: tumor cells, virus infected cells, microorganism infected cells, parasite infected cells, autoimmune cells, activated cells, myeloid cells, activated T-cells, B cells, or melanocytes; cells expressing the CD4, CD6, CD19, CD20, CD22, CD30, CD33, CD37, CD38, CD40, CD44, CD56, EpCAM, CanAg, CALLA, STEAP, TENB2, MUC16, IRTA1, IRTA2, IRTA3, IRTA4, IRTA5, c-MET, 5T4, or Her-2 antigens; Her-3 antigens or cells expressing insulin growth factor receptor, epidermal growth factor receptor, and folate receptor. 
     
     
         112 . The method of  claim 93 , wherein the cell-binding agent is an antibody, a single chain antibody, an antibody fragment that specifically binds to the target cell, a monoclonal antibody, a single chain monoclonal antibody, or a monoclonal antibody fragment that specifically binds the a target cell, a chimeric antibody, a chimeric antibody fragment that specifically binds to the target cell, a domain antibody, a domain antibody fragment that specifically binds to the target cell, a diabody, a nanobody, a probody, a Darpin, a lymphokine, a hormone, a vitamin, a growth factor, a colony stimulating factor, or a nutrient-transport molecule.