A two-column process for bispecific antibody purification based on MabSelect VL resin's strong byproduct removal capability.

Background: Protein L-conjugated resins are affinity media that bind to the variable region of the kappa light chain (LC) and have been used for initial product capture in the downstream processing of full-length antibodies and antibody fragments. Previous studies, including ours, have demonstrated that Protein L chromatography effectively separated various byproducts generated during the production of bispecific antibodies (bsAbs), including half-antibody, homodimer, LC-missing species, and aggregates. Cytiva recently launched its second-generation Protein L resin, MabSelect VL, which offers significantly improved binding capacity compared to its predecessor, Capto L.

Objective: This study aimed to explore the feasibility of developing a two-column process, which includes MabSelect VL capture step and a polishing step, for purification of complex antibody molecules.

Methods: We employed two bsAb cases to demonstrate that MabSelect VL's enhanced byproduct removal capability allows for a potential two-column purification process.

Results: For both bsAbs, the developed two-column process yielded a product with quality attributes comparable to those obtained using the traditional three-column process.

Conclusion: The MabSelect VL-based two-column process can be successfully applied to bsAb purification. In addition, it should also be feasible with regular monoclonal antibodies, whose purification is generally less challenging than that of bsAbs. By reducing the downstream process from three columns to two columns, significant savings in terms of time, labor, and materials can be achieved.