Patent ID: 6913748
Filing Date: 2005-07-05
Classification: A61K,A61P

Abstract:
1. A method of making a conjugate comprising a cell binding agent and one or more small molecule drugs, wherein said conjugate is represented by formula (V): wherein CB represents the cell binding agent, A represents the small molecule drug linked by a disulfide moiety, R, R 1 , R 2 and R 3 are the same or different and are H, methyl, ethyl, or linear, branched or cyclic alkyl having 3 to 6 carbon atoms, n is 0 or an integer from 1 to 4, and m is an integer of 1 to 10 or more, said method comprising: (1) reacting the cell binding agent with a cross-linker of the formula (I):  wherein X and Y are the same or different and are H, CONR to thereby give a compound of the formula (III):  wherein p represents an integer of 1 to 10 or more, and (2) reacting the compound of the formula (III) with one or more small molecule drugs comprising a free thiol group.