Patent ID: 7811572
Filing Date: 2010-10-12
Classification: A61K,A61P,C07K

Abstract:
1. A process for preparing a cell-binding agent-cytotoxic agent conjugate comprising the steps of: (a) contacting a cell-binding agent with a bifunctional crosslinking reagent to covalently attach a linker to the cell-binding agent and thereby prepare a first mixture comprising cell-binding agents having linkers bound thereto, wherein the cell-binding agent is selected from the group consisting of antibodies, interferons, interleukin 2 (IL-2), interleukin 3 (IL-3), interleukin 4 (IL-4), interleukin 6 (IL-6), insulin, EGF, TGF-α, FGF, G-CSF, VEGF, MCSF, GM-CSF, and transferrin, (b) subjecting the first mixture to tangential flow filtration and thereby prepare a purified first mixture of cell-binding agents having linkers bound thereto, (c) conjugating a cytotoxic agent to the cell-binding agents having linkers bound thereto in the purified first mixture by reacting the cell-binding agents having linkers bound thereto with a cytotoxic agent in a solution having a pH of about 4 to about 9 to prepare a second mixture comprising (i) cell-binding agent chemically coupled through the linker to the cytotoxic agent, (ii) free cytotoxic agent, and (iii) reaction by-products produced during step (c), wherein the cytotoxic agent is selected from the group consisting of maytansinoids, taxanes, and CC1065, and (d) subjecting the second mixture to tangential flow filtration to purify the cell-binding agents chemically coupled through the linkers to the cytotoxic agent from the other components of the second mixture and thereby prepare a purified second mixture of cell-binding agents chemically coupled through the linkers to the cytotoxic agent.