Method of targeting specific cell populations using cell-binding agent maytansinoid conjugates linked via a non-cleavable linker, said conjugates and methods of making said conjugates

1. A process of making a cell-binding agent maytansinoid conjugate, the process comprising:

(a) modifying a thiol-containing maytansinoid with a cross-linking agent to thereby form a non-cleavable linker comprising a S atom, and

(b) conjugating the modified thiol-containing maytansinoid with the cell-binding agent, thereby providing the non-cleavable linker between the cell-binding agent and the thiol-containing maytansinoid to produce a conjugate, wherein the non-cleavable linker is a linker that is substantially resistant to acid-induced cleavage, light-induced cleavage, peptidase-induced cleavage, esterase-induced cleavage, and disulfide bond cleavage, and wherein said cell-binding agent is an antibody, a single chain antibody or an antibody fragment that specifically bind to a target cell, wherein the antibody, single chain antibody or antibody fragment comprises a human constant region.

2. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the non-cleavable linker is derived from a maleimido-based moiety.

3. The process of making the cell-binding agent maytansinoid conjugate of claim 2 , wherein the non-cleavable linker is derived from a maleimido-based moiety selected from the group consisting of N-succinimidyl 4-(maleimidomethyl)cyclohexanecarboxylate (SMCC), N-succinimidyl-4-(N-maleimidomethyl)-cyclohexane-1-carboxy-(6-amidocaproate) (LC-SMCC), κ-maleimidoundecanoic acid N-succinimidyl ester (KMUThe), γ-maleimidobutyric acid N-succinimidyl ester (GMBS), ε-maleimidcaproic acid N-hydroxysuccinimide ester (EMCS), m-maleimidobenzoyl-N-hydroxysuccinimide ester(MBS), N-(α-maleimidoacetoxy)-succinimide ester (AMAS), succinimidyl-6-(β-maleimidopropionamido)hexanoate (SMPH), N-succinimidyl 4-(p-maleimidophenyl)-butyrate (SMPB), and N-(p-maleimidophenyl)isocyanate (PMPI).

4. The process of making the cell-binding agent maytansinoid conjugate of claim 3 , wherein the non-cleavable linker is SMCC.

5. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the non-cleavable linker is derived from a haloacetyl-based moiety.

6. The process of making the cell-binding agent maytansinoid conjugate of claim 5 , wherein the non-cleavable linker is derived from a haloacetyl-based moiety selected from the group consisting of N-succinimidyl-4-(iodoacetyl)-aminobenzoate (SIAB), N-succinimidyl iodoacetate (SIA), N-succinimidyl bromoacetate (SBA), and N-succinimidyl 3-(bromoacetamido)propionate (SBAP).

7. The process of making the cell-binding agent maytansinoid conjugate of claim 6 , wherein the non-cleavable linker is derived from SIAB.

8. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the linker is at any one of the C-3 hydroxyl, C-14 hydroxymethyl, C-15 hydroxyl or C-20 desmethyl groups of the at least one maytansinoid.

9. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the at least one maytansinoid is an N-methyl-alanine-containing ester of maytansinol.

10. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the at least one maytansinoid is an N-methyl-cysteine-containing ester of maytansinol.

11. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the at least one maytansinoid is represented by formula (II′-L), (II′-D) or (II′-D,L):

wherein:

Y 1 ′ represents

(CR 7 R 8 ) l (CR 9 ═CR 10 ) p (C≡C) q A o (CR 5 R 6 ) m D u (CR 11 ═CR 12 ) r (C≡C) s B t (CR 3 R 4 ) n CR 1 R 2 S—,

wherein:

R 1 to R 12 are each independently linear alkyl or alkenyl having 1 to 10 carbon atoms, branched or cyclic alkyl or alkenyl having 3 to 10 carbon atoms, phenyl, substituted phenyl or heterocyclic aromatic or heterocycloalkyl radical, and in addition, R 2 to R 12 can be H;

A, B, and D, each independently is cyclic alkyl or cyclic alkenyl having 3 to 10 carbon atoms, simple or substituted aryl, or heterocyclic aromatic or heterocycloalkyl radical;

l, m, n, o, p, q, r, s, t and u are each independently 0 or an integer of 1 to 5, provided that at least two of l, m, n, o, p, q, r, s, t and u are not both zero; and

May represents a maytansinoid that bears a side chain at C-3 hydroxyl, C-14 hydroxymethyl, C-15 hydroxyl or C-20 desmethyl.

12. The process of making the cell-binding agent maytansinoid conjugate of claim 11 , wherein R 1 is methyl and R 2 is H or R 1 and R 2 are methyl.

13. The process of making the cell-binding agent maytansinoid conjugate of claim 11 , wherein R 1 is methyl, R 2 is H, R 5 , R 6 , R 7 and R 8 are each H, l and m are each 1, and n is 0; or wherein R 1 and R 2 are methyl, R 5 , R 6 , R 7 , R 8 are each H, l and m are 1, and n is 0.

14. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the at least one maytansinoid is represented by formula (II-L), (II-D), or (II-D,L):

wherein:

Y i represents (CR 7 R 8 ) l (CR 5 R 6 ) m (CR 3 R 4 ) n CR 1 R 2 S—, wherein:

R 1 to R 8 are each independently, linear alkyl or alkenyl having 1 to 10 carbon atoms, branched or cyclic alkyl or alkenyl having 3 to 10 carbon atoms, phenyl, substituted phenyl or heterocyclic aromatic or heterocycloalkyl radical, and in addition R 2 to R 8 can be H;

l, m and n are each independently an integer of 1 to 5, and in addition n can be 0; and

May represents a maytansinoid that bears the side chain at C-3 hydroxyl, C-14 hydroxymethyl, C-15 hydroxyl or C-20 desmethyl.

15. The process of making the cell-binding agent maytansinoid conjugate of claim 14 , wherein R 1 is methyl and R 2 is H or R 1 and R 2 are methyl.

16. The process of making the cell-binding agent maytansinoid conjugate of claim 14 , wherein R 1 is methyl, R 2 is H, R 5 , R 6 , R 7 and R 8 are each H, l and m are each 1, and n is 0; or wherein R 1 and R 2 are methyl, R 5 , R 6 , R 7 , R 8 are each H, l and m are 1, and n is 0.

17. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the at least one maytansinoid is represented by formula 41′:

wherein:

Y 1 ′ represents

(CR 7 R 8 ) l (CR 9 ═CR 10 ) p (C≡C) q A o (CR 5 R 6 ) m D u (CR 11 ═CR 12 ) r (C≡C) s B t (CR 3 R 4 ) n CR 1 R 2 S—,

wherein:

R 1 to R 12 are each independently linear alkyl or alkenyl having 1 to 10 carbon atoms, branched or cyclic alkyl or alkenyl having 3 to 10 carbon atoms, phenyl, substituted phenyl or heterocyclic aromatic or heterocycloalkyl radical, and in addition, R 2 to R 12 can be H;

A, B, and D, each independently is cyclic alkyl or cyclic alkenyl having 3 to 10 carbon atoms, simple or substituted aryl, or heterocyclic aromatic or heterocycloalkyl radical;

l, m, n, o, p, q, r, s, t and u are each independently 0 or an integer of 1 to 5, provided that at least two of l, m, n, o, p, q, r, s, t and u are not both zero; and

May represents a maytansinoid that bears a side chain at C-3 hydroxyl, C-14 hydroxymethyl, C-15 hydroxyl or C-20 desmethyl.

18. The process of making the cell-binding agent maytansinoid conjugate of claim 17 , wherein R 1 is methyl and R 2 is H or R 1 and R 2 are methyl.

19. The process of making the cell-binding agent maytansinoid conjugate of claim 17 , wherein R 1 is methyl, R 2 is H, R 5 , R 6 , R 7 and R 8 are each H, l and m are each 1, and n is 0; or wherein R 1 and R 2 are methyl, R 5 , R 6 , R 7 , R 8 are each H, l and m are 1, and n is 0.

20. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the at least one maytansinoid is represented by formula 4 1 :

wherein:

Y i represents (CR 7 R 8 ) l (CR 5 R 6 ) m (CR 3 R 4 ) n CR 1 R 2 S—, wherein:

R 1 to R 8 are each independently, linear alkyl or alkenyl having 1 to 10 carbon atoms, branched or cyclic alkyl or alkenyl having 3 to 10 carbon atoms, phenyl, substituted phenyl or heterocyclic aromatic or heterocycloalkyl radical, and in addition R 2 to R 8 can be H; and

l, m and n are each independently an integer of 1 to 5, and in addition n can be 0.

21. The process of making the cell-binding agent maytansinoid conjugate of claim 20 , wherein R 1 is methyl and R 2 is H or R 1 and R 2 are methyl.

22. The process of making the cell-binding agent maytansinoid conjugate of claim 20 , wherein R 1 is methyl, R 2 is H, R 5 , R 6 , R 7 and R 8 are each H, l and m are each 1, and n is 0; or wherein R 1 and R 2 are methyl, R 5 , R 6 , R 7 , R 8 are each H, l and m are 1, and n is 0.

23. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the at least one maytansinoid is N 2′ -deacetyl-N 2′ -(3-mercapto-1-oxopropyl)-maytansine (DM1).

24. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the at least one maytansinoid is N 2′ -deacetyl-N 2′ -(4-mercapto-1-oxopentyl)-maytansine (DM3).

25. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the at least one maytansinoid is N 2′ -deacetyl-N 2′ -(4-methyl-4-mercapto-1-oxopentyl)-maytansine (DM4).

26. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the cell-binding agent binds to tumor cells; virus infected cells, microorganism infected cells, parasite infected cells, autoimmune cells, activated cells in graft rejection or graft vs. host disease, myeloid cells, activated T-cells, B cells, or melanocytes; cells expressing the CD33, CD19, CanAg, CALLA or Her2 antigen; or cells expressing insulin growth factor receptor, epidermal growth factor receptor or folate receptor.

27. The process of making the cell-binding agent maytansinoid conjugate of claim 26 , wherein the cell-binding agent binds to cells selected from the group consisting of breast cancer cells, kidney cancer cells, lung cancer cells, prostate cancer cells, ovarian cancer cells, colorectal cancer cells, gastric cancer cells, squamous cancer cells, small-cell lung cancer cells, testicular cancer cells, neuroblastoma cells, melanoma cells, and cells from cancer of the lymphatic organs or a combination thereof.

28. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a resurfaced antibody, a resurfaced single chain antibody, or a resurfaced antibody fragment that specifically binds to a target cell.

29. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a humanized antibody, a humanized single chain antibody, or a humanized antibody fragment that specifically binds to a target cell.

30. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a human antibody, a human single chain antibody, or a human antibody fragment that specifically binds to a target cell.

31. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a resurfaced monoclonal antibody, a resurfaced single chain monoclonal antibody, or a resurfaced monoclonal antibody fragment that specifically binds to a target cell.

32. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a humanized monoclonal antibody, a humanized single chain monoclonal antibody, or a humanized monoclonal antibody fragment that specifically binds to a target cell.

33. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a human monoclonal antibody, a human single chain monoclonal antibody, or a human monoclonal antibody fragment that specifically binds to a target cell.

34. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a resurfaced monoclonal antibody, a resurfaced single chain monoclonal antibody, or a resurfaced monoclonal antibody fragment that specifically binds to tumor cells.

35. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a humanized monoclonal antibody, a humanized single chain monoclonal antibody, or a humanized monoclonal antibody fragment that specifically binds to tumor cells.

36. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a human monoclonal antibody, a human single chain monoclonal antibody, or a human monoclonal antibody fragment that specifically binds to tumor cells.

37. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a resurfaced monoclonal antibody, a resurfaced single chain monoclonal antibody, or a resurfaced monoclonal antibody fragment that specifically binds to cancer cells selected from breast cancer cells, kidney cancer cells, lung cancer cells, prostate cancer cells, ovarian cancer cells, colorectal cancer cells, gastric cancer cells, squamous cancer cells, small-cell lung cancer cells, testicular cancer cells, neuroblastoma cells, melanoma cells, and cells from cancer of the lymphatic organs or a combination thereof.

38. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a humanized monoclonal antibody, a humanized single chain monoclonal antibody, or a humanized monoclonal antibody fragment that specifically binds to cancer cells selected from breast cancer cells, kidney cancer cells, lung cancer cells, prostate cancer cells, ovarian cancer cells, colorectal cancer cells, gastric cancer cells, squamous cancer cells, small-cell lung cancer cells, testicular cancer cells, neuroblastoma cells, melanoma cells, and cells from cancer of the lymphatic organs or a combination thereof.

39. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a human monoclonal antibody, a human single chain monoclonal antibody, or a human monoclonal antibody fragment that specifically binds to cancer cells selected from breast cancer cells, kidney cancer cells, lung cancer cells, prostate cancer cells, ovarian cancer cells, colorectal cancer cells, gastric cancer cells, squamous cancer cells, small-cell lung cancer cells, testicular cancer cells, neuroblastoma cells, melanoma cells, and cells from cancer of the lymphatic organs or a combination thereof.

40. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a resurfaced monoclonal antibody, a resurfaced single chain monoclonal antibody, or a resurfaced monoclonal antibody fragment that specifically binds to breast cancer cells.

41. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a humanized monoclonal antibody, a humanized single chain monoclonal antibody, or a humanized monoclonal antibody fragment that specifically binds to breast cancer cells.

42. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a human monoclonal antibody, a human single chain monoclonal antibody, or a human monoclonal antibody fragment that specifically binds to breast cancer cells.

43. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is an anti-IGF-IR antibody, an anti-PSMA antibody, an anti-CanAg antibody, an anti-CD19 antibody, an anti-CD33 antibody, an anti-CALLA antibody, an anti-CD56 antibody, or an anti-Her2 antibody.

44. The process of making the cell-binding agent maytansinoid conjugate of claim 43 , wherein the maytansinoid is N 2′ -deacetyl-N 2′ -(3-mercapto-1-oxopropyl)-maytansine (DM1), N 2′ -deacetyl-N- 2′ (4-mercapto-1-oxopentyl)-maytansine (DM3), or N 2′ -deacetyl-N 2′ -(4-methyl-4-mercapto-1-oxopentyl)-maytansine (DM4).

45. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a resurfaced or humanized My9-6 or N901 antibody or fragment thereof, wherein said My9-6 antibody comprises a heavy chain and a light chain, said heavy chain comprising three complementarity determining regions comprising HCCDR1, HCCDR2 and HCCDR3 of murine antibody My9-6, and wherein said light chain comprises three complementarity determining regions comprising LCCDR1, LCCDR2 and LCCDR3 of murine antibody My9-6; and wherein said resurfaced or humanized N901 antibody or fragment thereof comprises a heavy chain and a light chain, said heavy chain comprising three complementarity determining regions comprising HCCDR1, HCCDR2 and HCCDR3 of murine antibody N901, and said light chain comprising three complementarity determining regions comprising LCCDR1, LCCDR2 and LCCDR3 of murine antibody N901.

46. The process of making the cell-binding agent maytansinoid conjugate of claim 11 , wherein the maytansinoid is N 2′ -deacetyl-N- 2′ -(4-mercapto-1-oxopentyl)-maytansine (DM3) or N 2′ -deacetyl-N 2′ -(4-methyl-4-mercapto-1-oxopentyl)-maytansine (DM4).

47. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is the trastuzumab antibody, a resurfaced or humanized B4 antibody, or a resurfaced or humanized C242 antibody or fragment thereof, wherein said resurfaced or humanized C242 antibody comprises a heavy chain and a light chain, said heavy chain comprising three complementarity determining regions comprising HCCDR1, HCCDR2 and HCCDR3 of murine antibody C242, and said light chain comprising three complementarity determining regions comprising LCCDR1, LCCDR2 and LCCDR3 of murine antibody C242.

48. The process of making the cell-binding agent maytansinoid conjugate of claim 47 , wherein the maytansinoid is N 2′ -deacetyl-N 2′ -(3-mercapto-1-oxopropyl)-maytansine (DM1), N 2′ -deacetyl-N- 2′ (4-mercapto-1-oxopentyl)-maytansine (DM3), or N 2′ -deacetyl-N 2′ -(4-methyl-4-mercapto-1-oxopentyl)-maytansine (DM4).

49. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a resurfaced or humanized B4 antibody.

50. The process of making the cell-binding agent maytansinoid conjugate of claim 1 ,

wherein the cell-binding agent is a resurfaced or humanized C242 antibody or fragment thereof, wherein said resurfaced or humanized C242 antibody comprises a heavy chain and a light chain, said heavy chain comprising three complementarity determining regions comprising HCCDR1, HCCDR2 and HCCDR3 of murine antibody C242, and said light chain comprising three complementarity determining regions comprising LCCDR1, LCCDR2 and LCCDR3 of murine antibody C242.

51. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the cell-binding agent maytansinoid conjugate has the structure:

52. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein an average of 1 to about 10 maytansinoids is covalently linked to the cell-binding agent.

53. The process of making the cell-binding agent maytansinoid conjugate of claim 1 , wherein the cell-binding agent is a humanized antibody, a humanized single chain antibody or a humanized antibody fragment that specifically binds to target cells, the maytansinoid is N 2′ -deacetyl-N 2′ -(3-mercapto-1-oxopropyl)-maytansine (DM1) and the linker is derived from SMCC.