Patent ID: 11173213

Abstract:
A method for producing an antibody-drug conjugate composition, comprising: (i) a step of reacting an antibody with a reducing agent in a buffer to reduce interchain disulfides, and (ii) a step of reacting drug linker intermediates with the antibody having thiol groups obtained in the step (i), wherein the reaction temperature in the step (i) is −10° C. to 10° C., and the average number of bound drugs in the produced antibody-drug conjugate composition is 3.5 to 4.5, and the content of antibody-drug conjugates in which four drug linkers are bound to heavy-light interchain thiols, in the produced antibody-drug conjugate composition is 50% or more; and an antibody-drug conjugate composition, wherein the content of antibody-drug conjugates wherein the average number of bound drugs is 3.5 to 4.5, and the content of antibody-drug conjugates in which four drug linkers are bound to heavy-light interchain thiols, is 50% or more.