Bis(vinylsulfonyl)piperazines as efficient linkers for highly homogeneous antibody-drug conjugates

Disulfide re-bridging strategy has demonstrated significant advantages in the construction of homogeneous antibody drug conjugates (ADCs). However, a major issue that disulfide scrambling at the hinge region of antibody leads to the formation of "half-antibody" has appeared for many re-bridging linkers. We present bis(vinylsulfonyl)piperazines (BVP) as efficient linkers to selectively re-bridge disulfides at the antigen-binding fragment (Fab) regions and produce highly homogeneous conjugates with a loading of two drugs without disulfide scrambling. We also found that optically active (S)-configuration linkers led to more sufficient conjugation compared with (R)-configuration. The BVP-linked ADCs demonstrated superior efficacy and antigen-selectivity in vitro cytotoxicity.