Removing light chain-missing byproducts and aggregates by Capto MMC ImpRes mixed-mode chromatography during the purification of two WuXiBody-based bispecific antibodies

WuXiBody is a novel bispecific antibody (bsAb) platform developed by WuXi Biologics. Its key feature is the replacement of one parental antibody's CH1/CL constant region with the T cell receptor (TCR) constant domain, a design aimed at promoting cognate heavy chain (HC)-light chain (LC) pairing. BsAbs based on WuXiBody can adopt either asymmetric or symmetric format. LC-missing species, a byproduct frequently associated with bsAb containing sequence engineered Fab arm, is also identified during WuXiBody production. Nevertheless, WuXiBody's unique design greatly facilitates removal of this type of impurity, which can otherwise be difficult to clear. In this work, with two concrete cases (WuXiBodies with asymmetric and symmetric designs, respectively), we showed that Capto MMC ImpRes mixed-mode chromatography can effectively remove LC-missing byproducts as well as aggregates, demonstrating that this resin is a powerful tool for WuXiBody purification.