The superiority of MabSelect VL, Cytiva's second-generation Protein L resin, over three other affinity resins in purifying a VHH-containing trispecific antibody

Affinity chromatography is widely utilized for initial product capture in antibody purification. Besides Protein A resins, other affinity resins that bind different subdomains of an antibody have also been developed. For example, Protein L resin, KappaSelect, LambdaFabSelect and Praesto 70 CH1 selectively bind the variable region of kappa light chain (LC), constant region of kappa LC, constant region of lambda LC and CH1 domain of the heavy chain (HC), respectively. Affinity media with distinct specificities provide more options for antibody purification. For a given bispecific antibody (bsAb) purification case, depending on the composition difference between the product and byproducts, one affinity resin may outperform the others for byproduct removal. In the current study, we compared four affinity resins, Praesto Jetted A50 (a Protein A resin), Praesto 70 CH1, KappaSelect and MabSelect VL (Cytiva's second-generation Protein L resin), for their effectiveness in removing byproducts associated with a VHH-containing trispecific antibody (TsAb). The data suggested that the three non-Protein A resins outperformed the Protein A resin for byproduct removal. Among the three non-Protein A resins, MabSelect VL provided the best byproduct clearance, and it removed half-antibody, homodimers and most aggregates. This work reconfirms the necessity of screening different affinity resins with distinct specificities for achieving the best separation.