	US 12,109,273 B2
	Process for preparing antibody-drug conjugates with improved homogeneity
Ao Ji, Shanghai (CN); Chuchu Sun, Shanghai (CN); and Wenxu He, Shanghai (CN)
Assigned to WUXI XDC SINGAPORE PRIVATE LIMITED, Singapore (SG)
Filed by WUXI XDC SINGAPORE PRIVATE LIMITED, Singapore (SG)
Filed on Aug. 24, 2021, as Appl. No. 17/410,574.
Application 17/410,574 is a continuation of application No. 17/430,494, granted, now 11,478,553, previously published as PCT/CN2020/075162, filed on Feb. 14, 2020.
Claims priority of application No. PCT/CN2019/075217 (WO), filed on Feb. 15, 2019.
Prior Publication US 2021/0379193 A1, Dec. 9, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. A61K 47/68 (2017.01); A61K 31/40 (2006.01); C07K 16/28 (2006.01); C07K 16/32 (2006.01)

CPC A61K 47/6803 (2017.08) [A61K 31/40 (2013.01); C07K 16/2863 (2013.01); C07K 16/2887 (2013.01); C07K 16/32 (2013.01); C07K 2317/24 (2013.01); C07K 2317/55 (2013.01)]

19 Claims

1. A method of preparing an antibody-drug conjugate (ADC), comprising the following steps:

(a) incubating a reductant and an antibody in the presence of an effective amount of a transition metal ion in a buffer system to reduce inter-chain disulfide bonds within the antibody to generate reduced thiol groups; and

(b) introducing an excess amount of payload having a reactive group to react with the reduced thiol groups resulted from step (a).