Targeted pyrrolobenzodiazapine conjugates

Abstract

Provided are Conjugate comprising PBDs conjugated to a targeting agent and methods of using such PBDs.

1 . A conjugate having formula I:
   L-(LU-D) p    (I)
   or a pharmaceutically acceptable salt thereof;   wherein L is a Ligand unit selected from the group consisting of an antibody, an antigen-binding fragment of an antibody and a Fc fusion protein,   LU is a Linker unit of formula Ia:
   -A 1 -L 1 -,   (1a)
 
   wherein:
 L 1  is an amino acid sequence comprising a dipeptide of formula —NH—X 1 -X 2 —CO—, wherein —NH— is the amino group of X 1 , and CO is the carbonyl group of X 2 , and wherein the peptide is cleavable by the action of an enzyme to release fee drug, wherein the enzyme is a cathepsin; 
   A 1  is a Stretcher Unit, wherein A 1  comprises the functionality —CO— connected directly to the amino terminus of X 1  thereby to form an amide link with —X 1 — and wherein A 1  is further comprised of the structure:   
       
         
           
           
               
               
           
         
         wherein the wavy line indicates the point of attachment to the Ligand unit wherein S is a sulfur atom derived from the Ligand Unit, and the asterisk indicates the bond to the remaining portion of A 1 : 
         p is 1 to 20; and 
         D is a Drug unit wherein the Drug unit is a PBD dimer having the following formula II: 
       
       
         
           
           
               
               
           
         
         wherein: 
         R 2  is of formula III: 
       
       
         
           
           
               
               
           
         
         wherein A is a C 5-7  aryl group, X is connected to the Linker unit and is selected from the group consisting of —O—, —S—, —C(O)O—, —C(O)—, —NH(C═O)—, and —N(R N )—, wherein R N  is selected from the group consisting of H, C 1-4  alkyl and (C 2 H 4 O) m CH 3 , where m is 1 to 3, and either:
 (i) Q 1  is a single bond, and Q 2  is selected from the group consisting of a single bond and —Z—(CH 2 ) n —, wherein Z is selected from the group consisting of a single bond, O, S and NH and n is from 1 to 3, or 
 (ii) Q 1  is —CH═CH— and Q 2  is a single bond; 
 
         R 12  is a C 5-10  aryl group optionally substituted by one or more substituents selected from the group consisting of halo, nitro, cyano, C 1-7  alkoxy, C 1-7  alkyl, C 3-7  heterocyclyl and bis-oxy-C 1-3  alkylene; 
         R 6  and R 9  are independently selected from the group consisting of H, R, OH, OR, SH, SR, NH 2 , NHR, NRR′, nitro, Me 3 Sn and halo; 
         R 7  is selected from the group consisting of H, R, OH, OR, SH, SR, NH 2 , NHR, NRR′, nitro, Me 3 Sn and halo; 
         wherein R and R′ are independently selected from the group consisting of optionally substituted C 1-12  alkyl, C 3-20  heterocyclyl, and C 5-20  aryl groups; 
         either:
 (a) R 10  is H, and R 11  is OH, OR A , wherein R A  is C 1-4  alkyl, or 
 (b) R 10  and R 11  form a nitrogen-carbon double bond between the nitrogen and carbon atoms to which they are bound, or 
 (c) R 10  is H and R 11  is SO z M, wherein z is 2; 
 
         R″ is a C 3-12  alkylene group optionally interrupted by one or more heteroatoms selected from the group consisting of O, S, and NH, or by an aromatic ring; 
         Y and Y′ are selected from the group consisting of O, S, and NH; 
         R 6′ , R 7′ , R 9′  are selected from the same groups as R 6 , R 7  and R 9  respectively, and R 10′  and R 11′  are the same as R 10  and R 11 , and each M is a monovalent pharmaceutically acceptable cation or both M groups together are a divalent pharmaceutically acceptable cation; 
         wherein C 3-20  heterocyclyl is a monovalent moiety obtained by removing a hydrogen atom of a heterocyclic compound which has 3 to 20 ring atoms, of which 1 to 10 are heteroatoms selected from the group consisting of N, O and S; and 
         wherein C 3-7  heterocyclyl is a monovalent moiety obtained by removing a hydrogen atom of a heterocyclic compound which has 3 to 7 ring atoms, of which 1 to 4 are heteroatoms selected from the group consisting of N, O and S. 
       
     
     
         2 . The conjugate according to  claim 1  wherein the dipeptide of formula —NH—X 1 -X 2 —CO—, is selected from the group consisting of -Phe-Lys-,-Val-Ala-, -Val-Lys-, -Ala-Lys-, -Val-Cit-,-Phe-Cit-, -Leu-Cit-, -Ile-Cit-, -Phe-Arg-, and -Trp-Cit-, wherein Cit is citrulline. 
     
     
         3 . The conjugate according to  claim 1  wherein A 1  is selected from the group consisting of: 
       
         
           
           
               
               
           
         
         wherein the asterisk indicates the point of attachment to the amino group of X 1 , the wavy line indicates the point of attachment to the Ligand unit, n is 0 or 1, and m is 0 to 30; and 
       
       
         
           
           
               
               
           
         
         wherein the asterisk indicates the point of attachment to the amino group of X 1 , the wavy line indicates the point of attachment to the Ligand unit, n is 0 or 1, and m is 0 to 30. 
       
     
     
         4 . The conjugate according to  claim 2 , wherein R 7  is selected from the group consisting of H, OH and OR. 
     
     
         5 . The conjugate according to  claim 2 , wherein R 7  is a C 1-4  alkyloxy group. 
     
     
         6 . The conjugate according to  claim 4 , wherein Y and Y′ are O. 
     
     
         7 . The conjugate according to  claim 6 , wherein R″ is C 3-7  alkylene. 
     
     
         8 . The conjugate according to  claim 7 , wherein R 9  is H. 
     
     
         9 . The conjugate according to  claim 8 , wherein R 6  is selected from the group consisting of H and halo. 
     
     
         10 . The conjugate according to  claim 1 , wherein A is phenyl, X is selected from the group consisting of —O—, —S—, and —NH—, and Q 1  is a single bond. 
     
     
         11 . The conjugate according to  claim 10 , wherein X is NH. 
     
     
         12 . The conjugate according to  claim 11 , wherein Q 1  is a single bond and Q 2  is a single bond. 
     
     
         13 . The conjugate according to  claim 1 , wherein R 12  is a C 5-7  aryl group optionally substituted by one or more substituents selected from the group consisting of halo, nitro, cyano, C 1-7  alkoxy, C 5-20  aryloxy, C 3-20  heterocyclyoxy, C 1-7  alkyl, C 3-7  heterocyclyl and bis-oxy-C 1-3  alkylene wherein the C 1-7  alkoxy group is optionally substituted by an amino group, and if the C 3-7  heterocyclyl group is a C 6  nitrogen containing heterocyclyl group, it is optionally substituted by a C 1-4  alkyl group. 
     
     
         14 . The conjugate according to  claim 13 , wherein the C 6-7  aryl group is an optionally substituted phenyl group. 
     
     
         15 . The conjugate according to  claim 14 , wherein R 12  bears one to three substituent groups. 
     
     
         16 . The conjugate according to  claim 1 , wherein R 10  and R 11  form a nitrogen-carbon double bond. 
     
     
         17 . The conjugate according to  claim 1 , wherein R 6′ , R 7′ , R 9′ , and Y′ are the same as R 6 , R 7 , R 9 , and Y respectively. 
     
     
         18 . The conjugate according to  claim 1  wherein D has the formula: 
       
         
           
           
               
               
           
         
         wherein the wavy line of D indicates covalent attachment to LU and A 1  is selected from the group consisting of: 
       
       
         
           
           
               
               
           
         
         wherein the asterisk indicates the point of attachment to the amino group of X 1 , the wavy line to A 1  indicates the point of attachment to the Ligand unit, n is 0 or 1, and m is 0 to 30; and 
       
       
         
           
           
               
               
           
         
         wherein the asterisk indicates the point of attachment to the amino group of X 1 , the wavy line indicates the point of attachment to the Ligand unit, n is 0 or 1, and m is 0 to 30. 
       
     
     
         19 . The conjugate according to  claim 18  wherein D has the formula: 
       
         
           
           
               
               
           
         
       
     
     
         20 . The conjugate according to  claim 18  wherein D has the formula: 
       
         
           
           
               
               
           
         
       
     
     
         21 . The conjugate according to  claim 19  wherein the Ligand unit is an antibody and wherein the sulfur atom bonding the antibody Ligand Unit to A 1  of the Linker unit is from a thiol group of a cysteine residue of the antibody. 
     
     
         22 . The conjugate according to  claim 21  wherein the cysteine residue is an introduced cysteine residue in the heavy chain or light chain of the antibody or antigen binding fragment thereof. 
     
     
         23 . The conjugate according to  claim 22  wherein the introduced cysteine is at amino acid heavy chain position 239, according to the EU numbering system. 
     
     
         24 . The conjugate according to  claim 21  wherein the antibody is a humanized 1F6 antibody 
     
     
         25 . The conjugate according to  claim 23  wherein the antibody is a humanized 1F6 antibody. 
     
     
         26 . A Drug Linker having the formula:
   G 1 -L 1 -D   or a salt thereof;   wherein L 1  is an amino acid sequence comprising a dipeptide of formula —NH—X 1 -X 2 —CO—, wherein —NH— is the amino group of X 1 , and CO is the carbonyl group of X 2 , and wherein the peptide is cleavable by the action of an enzyme to release fee drug, wherein the enzyme is a cathepsin;   G 1  is a Stretcher Unit to form a connection to a Ligand unit, wherein G 1  is comprised of a maleimide group for reaction with a thiol group on the Ligand unit for said connection, and wherein G 1  further comprises the functionality —CO— connected directly to the amino terminus of X 1  thereby to form an amide link with —X 1 —   and D is a Drug unit wherein the Drug unit is a PBD dimer having the following formula II:   
       
         
           
           
               
               
           
         
         wherein: 
         R 2  is of formula III: 
       
       
         
           
           
               
               
           
         
         wherein A is a C 5-7  aryl group, X is connected to the Linker unit and is selected from the group consisting of —O—, —S—, —C(O)O—, —C(O)—, —NH(C═O)—, and —N(R N )—, wherein R N  is selected from the group consisting of H, C 1-4  alkyl and (C 2 H 4 O) m CH 3 , where m is 1 to 3, and either:
 (i) Q 1  is a single bond, and Q 2  is selected from the group consisting of a single bond and —Z—(CH 2 ) n —, wherein Z is selected from the group consisting of a single bond, O, S and NH and n is from 1 to 3, or 
 (ii) Q 1  is —CH═CH— and Q 2  is a single bond; 
 
         R 12  is a C 5-10  aryl group, optionally substituted by one or more substituents selected from the group consisting of halo, nitro, cyano, C 1-7  alkoxy, C 1-7  alkyl, C 3-7  heterocyclyl and bis-oxy-C 1-3  alkylene; 
         R 6  and R 9  are independently selected from the group consisting of H, R, OH, OR, SH, SR, NH 2 , NHR, NRR′, nitro, Me 3 Sn and halo; 
         R 7  is selected from the group consisting of H, R, OH, OR, SH, SR, NH 2 , NHR, NRR′, nitro, Me 3 Sn and halo; 
         wherein R and R′ are independently selected from the group consisting of optionally substituted C 1-12  alkyl, C 3-20  heterocyclyl, and C 5-20  aryl groups; 
         either;
 (a) R 10  is H, and R 11  is OH, OR A , wherein R A  is C 1-4  alkyl, or 
 (b) R 10  and R 11  form a nitrogen-carbon double bond between the nitrogen and carbon atoms to which they are bound, or 
 (c) R 10  is H and R 11  is SO z M, wherein z is 2; 
 
         R″ is a C 3-12  alkylene group, which chain is optionally interrupted by one or more heteroatoms, selected from the group consisting of O, S, and NH, or by an aromatic ring; 
         Y and Y′ are selected from the group consisting of O, S, and NH; 
         R 6′ , R 7′ , R 9′  are selected from the same groups as R 6 , R 7  and R 9  respectively, and R 10′  and R 11′  are the same as R 10  and R 11  and each M is a monovalent pharmaceutically acceptable cation or both M groups together are a divalent pharmaceutically acceptable cation; 
         wherein C 3-20  heterocyclyl is a monovalent moiety obtained by removing a hydrogen atom of a heterocyclic compound which has 3 to 20 ring atoms, of which 1 to 10 are heteroatoms selected from the group consisting of N, O and S; and 
         wherein C 3-7  heterocyclyl is a monovalent moiety obtained by removing a hydrogen atom of a heterocyclic compound which has 3 to 7 ring atoms, of which 1 to 4 are heteroatoms selected from the group consisting of N, O and S. 
       
     
     
         27 . The Drug Linker according to  claim 26  wherein the dipeptide of formula —NH—X 1 -X 2 —CO—, is selected from the group consisting of -Phe-Lys-,-Val-Ala-, -Val-Lys-, -Ala-Lys-, -Val-Cit-,-Phe-Cit-, -Leu-Cit-, -Ile-Cit-, -Phe-Arg-, and -Trp-Cit-, wherein Cit is citrulline. 
     
     
         28 . The Drug Linker according to  claim 26 , wherein G 1  is selected from the group consisting of: 
       
         
           
           
               
               
           
         
         wherein the asterisk indicates the point of attachment to the a group of X 1 , n is 0 or 1, and m is 0 to 30; and 
       
       
         
           
           
               
               
           
         
         wherein the asterisk indicates the point of attachment to the amino group of n is 0 or 1, and m is 0 to 30. 
       
     
     
         29 . The Drug linker according to  claim 27 , wherein R 7  is selected from the group consisting of H, OH and OR. 
     
     
         30 . The Drug linker according to  claim 27 , wherein R 7  is a C 1-4  alkyloxy group. 
     
     
         31 . The Drug linker according to  claim 30 , wherein Y and Y′ are O. 
     
     
         32 . The Drug linker according to  claim 31 , wherein R″ is C 3-7  alkylene. 
     
     
         33 . The Drug linker according to  claim 32 , wherein R 9  is H. 
     
     
         34 . The Drug linker according to  claim 33 , wherein R 6  is selected from the group consisting of H and halo. 
     
     
         35 . The Drug linker according to  claim 26 , wherein A is phenyl, X is selected from the group consisting of —O—, —S—, and —NH—, and Q 1  is a single bond. 
     
     
         36 . The Drug linker according to  claim 35 , wherein X is NH. 
     
     
         37 . The Drug linker according to  claim 36 , wherein Q 1  is a single bond and Q 2  is a single bond. 
     
     
         38 . The Drug linker according to  claim 26 , wherein R 12  is a C 5-7  aryl group optionally substituted by one or more substituents selected from the group consisting of halo, nitro, cyano, C 1-7  alkoxy, C 5-20  aryloxy, C 3-20  heterocyclyoxy, C 1-7  alkyl, C 3-7  heterocyclyl and bis-oxy-C 1-3  alkylene wherein the C 1-7  alkoxy group is optionally substituted by an amino group, and if the C 3-7  heterocyclyl group is a C 6  nitrogen containing heterocyclyl group, it is optionally substituted by a C 1-4  alkyl group. 
     
     
         39 . The Drug linker according to  claim 38 , wherein the C 5-7  aryl group is an optionally substituted phenyl group. 
     
     
         40 . The Drug linker according to  claim 39 , wherein R 12  bears one to three substituent groups. 
     
     
         41 . The Drug linker according to  claim 26 , wherein R 10  and R 11  form a nitrogen-carbon double bond. 
     
     
         42 . The Drug linker according to  claim 26 , wherein R 6′ , R 7′ , R 9′ , and Y′ are the same as R 6 , R 7 , R 9 , and Y respectively. 
     
     
         43 . The Drug linker according to  claim 26  wherein D has the formula: 
       
         
           
           
               
               
           
         
         wherein the wavy line of D indicates covalent attachment to LU. 
       
     
     
         44 . The Drug linker according to  claim 43  wherein D has the formula: 
       
         
           
           
               
               
           
         
         wherein the wavy line of D indicates covalent attachment to LU. 
       
     
     
         45 . The Drug linker according to  claim 43  wherein D has the formula: 
       
         
           
           
               
               
           
         
         wherein the wavy line of D indicates covalent attachment to LU. 
       
     
     
         46 . The Drug linker according to  claim 26 , wherein the Drug linker has the formula of: 
       
         
           
           
               
               
           
         
       
     
     
         47 . A method of treating a mammal having a proliferative disease wherein the cell surface antigen bound by the Ligand unit is expressed by proliferative cells of the proliferative disease comprising administering an effective amount of the conjugate of  claim 1 , wherein the proliferative disease treated is selected from the group consisting of renal cell carcinoma, Hodgkin Lymphoma, anaplastic large cell lymphoma and leukemia.