Patent ID: 11945882
Assignee: DAIICHI SANKYO COMPANY, LIMITED
Field: Pharmaceuticals (Chemistry)
Classification: CPC C  A  Y | IPC C

Claim 42:
43. A method for producing an antibody-drug conjugate in which a drug-linker represented by formula (19) is conjugated to an antibody via a thioether bond:, wherein A represents a connecting position to the antibody, wherein the method comprises the steps of:
i) producing crystals of a compound represented by formula (1):, by preparing a solution in which the compound represented by the formula (1) is dissolved, wherein the solution comprises a lower ketone and a lower alcohol as solvents, wherein the lower ketone is acetone and the lower alcohol is 1-propanol or 2-butanol; and then precipitating crystals of the compound represented by the formula (1) from the solution;
ii) reducing an antibody; and then
iii) adding a solution in which the crystals of the compound represented by the formula (1) produced in step i) are dissolved, to react the solution with the reduced antibody.