Compositions and methods for the depletion of cd5+ cells

Abstract

The invention provides anti-CD5 antibodies, antigen-binding fragments thereof, and antibody drug conjugates thereof, for use in treating, for example, a stem cell disorder, cancer, or autoimmune disease, among other hematological and proliferative diseases. Compositions and methods for depleting populations of CD5+ cells, such as CD5+ cancer cells and CD5+ immune cells are described, and can be used to treat cancers and autoimmune diseases directly as stand-alone therapies by eradicating cancerous cells and autoreactive immune cells that express CD5 and/or to prepare a patient for hematopoietic stem cell transplantation, for instance, by depleting populations of CD5+ immune cells that cross-react with, and mount an immune response against, non-self hematopoietic stem cells.

1 . A method of depleting a population of CD5+ cells in a human patient, the method comprising administering to the human patient an effective amount of a conjugate comprising an anti-CD5 antibody, or antigen binding fragment thereof, conjugated to an amatoxin via a linker, wherein the conjugate is represented by the formula Ab-Z-L-Am, wherein Ab is the anti-CD5 antibody or antigen-binding fragment thereof, L is the linker, Z is a chemical moiety, and Am an amatoxin represented by formula (I) 
       
         
           
           
               
               
           
         
         wherein R 1  is H, OH, OR A , or OR C ; 
         R 2  is H, OH, ORB, or OR C ; 
         R A  and R B , when present, together with the oxygen atoms to which they are bound, combine to form an optionally substituted 5-membered heterocyclolalkyl group; 
         R 3  is H, R C , or R D ; 
         R 4 , R 5 , R 6 , and R 7  are each independently H, OH, OR C , OR D , R C , or R D ; 
         R 8  is OH, NH 2 , OR C , OR D , NHR C , or NR C R D ; 
         R 9  is H, OH, OR C , or OR D ; 
         X is —S—, —S(O)—, or —SO 2 —; 
         R C  is -L-Z; 
         R D  is optionally substituted C 1 -C 6  alkyl, optionally substituted C 1 -C 6  heteroalkyl, optionally substituted C 2 -C 6  alkenyl, optionally substituted C 2 -C 6  heteroalkenyl, optionally substituted C 2 -C 6  alkynyl, optionally substituted C 2 -C 6  heteroalkynyl, optionally substituted cycloalkyl, optionally substituted heterocycloalkyl, optionally substituted aryl, or optionally substituted heteroaryl; 
         L is optionally substituted C 1 -C 6  alkylene, optionally substituted C 1 -C 6  heteroalkylene, optionally substituted C 2 -C 6  alkenylene, optionally substituted C 2 -C 6  heteroalkenylene, optionally substituted C 2 -C 6  alkynylene, optionally substituted C 2 -C 6  heteroalkynylene, optionally substituted cycloalkylene, optionally substituted heterocycloalkylene, optionally substituted arylene, optionally substituted heteroarylene; a dipeptide, —C(═O)—, a peptide. or a combination thereof; and 
         Z is a chemical moiety formed from a coupling reaction between a reactive substituent present on L and a reactive substituent present within the antibody or antigen-binding fragment thereof, 
         wherein Am comprises exactly one R C  substituent. 
       
     
     
         2 . The method of  claim 1 , wherein the amatoxin is conjugated to the antibody, or an antigen binding fragment thereof, by way of a cysteine residue in the Fc domain of the antibody, or antigen binding fragment thereof. 
     
     
         3 . The method of  claim 1 , wherein the human patient has a hematological cancer. 
     
     
         4 . The method of  claim 3 , wherein the hematological cancer is leukemia or lymphoma. 
     
     
         5 . The method of  claim 1 , wherein the human patient has an autoimmune disease. 
     
     
         6 . The method of  claim 1 , wherein the antibody, or the antigen binding fragment thereof, comprises a heavy chain variable region (VH) comprising a CDR1 having an amino acid sequence as set forth in SEQ ID NO: 29, a CDR2 having an amino acid sequence as set forth in SEQ ID NO: 30, and a CDR3 having an amino acid sequence as set forth in SEQ ID NO: 31, and comprising a light chain variable region comprising a CDR1 having an amino acid sequence as set forth in SEQ ID NO: 32, a CDR2 having an amino acid sequence as set forth in SEQ ID NO: 33, and a CDR3 having an amino acid sequence as set forth in SEQ ID NO: 34. 
     
     
         7 . The method of  claim 1 , wherein the antibody, or the antigen binding fragment thereof, comprises a heavy chain variable region (VH) comprising an amino acid sequence as set forth in SEQ ID NO: 257 and a light chain variable region (VL) comprising an amino acid sequence as set forth in SEQ ID NO: 258. 
     
     
         8 . The method of  claim 1 , wherein R 5  is OR C . 
     
     
         9 . The method of  claim 1 , wherein R 8  is NHR C . 
     
     
         10 . The method of  claim 1 , wherein L is a linker which is C 1 -C 6  alkylene, C 1 -C 6  heteroalkylene, C 2 -C 6  alkenylene, C 2 -C 6  heteroalkenylene, C 2 -C 6  alkynylene, or C 2 -C 6  heteroalkynylene 
     
     
         11 . The method of  claim 1 , wherein L is a linker which comprises a peptide. 
     
     
         12 . A method of conditioning a human patient for receiving a hematopoietic stem cell (HSC) transplant, the method comprising administering to the human patient in need of an HSC transplant an effective amount of a conjugate comprising an amatoxin conjugated to an anti-CD5 antibody, or an antigen binding fragment thereof, wherein the conjugate is represented by the formula Ab-Z-L-Am, wherein Ab is the anti-CD5 antibody or antigen-binding fragment thereof, L is the linker, Z is a chemical moiety, and Am an amatoxin represented by formula (I) 
       
         
           
           
               
               
           
         
         wherein R 1  is H, OH, OR A , or OR C ; 
         R 2  is H, OH, ORB, or OR C ; 
         R A  and R B , when present, together with the oxygen atoms to which they are bound, combine to form an optionally substituted 5-membered heterocyclolalkyl group; 
         R 3  is H, R C , or R D ; 
         R 4 , R 5 , R 6 , and R 7  are each independently H, OH, OR C , OR D , R C , or R D ; 
         R 8  is OH, NH 2 , OR C , OR D , NHR C , or NR C R D ; 
         R 9  is H, OH, OR C , or OR D ; 
         X is —S—, —S(O)—, or —SO 2 —; 
         R C  is -L-Z; 
         R D  is optionally substituted C 1 -C 6  alkyl, optionally substituted C 1 -C 6  heteroalkyl, optionally substituted C 2 -C 6  alkenyl, optionally substituted C 2 -C 6  heteroalkenyl, optionally substituted C 2 -C 6  alkynyl, optionally substituted C 2 -C 6  heteroalkynyl, optionally substituted cycloalkyl, optionally substituted heterocycloalkyl, optionally substituted aryl, or optionally substituted heteroaryl; 
         L is optionally substituted C 1 -C 6  alkylene, optionally substituted C 1 -C 6  heteroalkylene, optionally substituted C 2 -C 6  alkenylene, optionally substituted C 2 -C 6  heteroalkenylene, optionally substituted C 2 -C 6  alkynylene, optionally substituted C 2 -C 6  heteroalkynylene, optionally substituted cycloalkylene, optionally substituted heterocycloalkylene, optionally substituted arylene, optionally substituted heteroarylene; a dipeptide, —C(═O)—, a peptide. or a combination thereof; and 
         Z is a chemical moiety formed from a coupling reaction between a reactive substituent present on L and a reactive substituent present within the antibody or antigen-binding fragment thereof, 
         wherein Am comprises exactly one R C  substituent. 
       
     
     
         13 . The method of  claim 12 , wherein the amatoxin is conjugated to the antibody, or an antigen binding fragment thereof, by way of a cysteine residue in the Fc domain of the antibody, or antigen binding fragment thereof. 
     
     
         14 . The method of  claim 12 , wherein the human patient has a hematological cancer. 
     
     
         15 . The method of  claim 14 , wherein the hematological cancer is leukemia or lymphoma. 
     
     
         16 . The method of  claim 12 , wherein the human patient has an autoimmune disease. 
     
     
         17 . The method of  claim 12 , wherein the antibody, or the antigen binding fragment thereof, comprises a heavy chain variable region (VH) comprising a CDR1 having an amino acid sequence as set forth in SEQ ID NO: 29, a CDR2 having an amino acid sequence as set forth in SEQ ID NO: 30, and a CDR3 having an amino acid sequence as set forth in SEQ ID NO: 31, and comprising a light chain variable region comprising a CDR1 having an amino acid sequence as set forth in SEQ ID NO: 32, a CDR2 having an amino acid sequence as set forth in SEQ ID NO: 33, and a CDR3 having an amino acid sequence as set forth in SEQ ID NO: 34. 
     
     
         18 . The method of  claim 12 , wherein the antibody, or the antigen binding fragment thereof, comprises a heavy chain variable region (VH) comprising an amino acid sequence as set forth in SEQ ID NO: 257 and a light chain variable region (VL) comprising an amino acid sequence as set forth in SEQ ID NO: 258. 
     
     
         19 . The method of  claim 12 , wherein R 5  is OR C . 
     
     
         20 . The method of  claim 12 , wherein R 8  is NHR C . 
     
     
         21 . The method of  claim 12 , wherein L is a linker which is C 1 -C 6  alkylene, C 1 -C 6  heteroalkylene, C 2 -C 6  alkenylene, C 2 -C 6  heteroalkenylene, C 2 -C 6  alkynylene, or C 2 -C 6  heteroalkynylene 
     
     
         22 . The method of  claim 12 , wherein L is a linker which comprises a peptide.