High-Throughput Generation of Bipod (Fab × scFv) Bispecific Antibodies Exploits Differential Chain Expression and Affinity Capture
Thomas Nesspor, Kyle Kinealy, Nicholas Mazzanti, Michael Diem, Kevin Boyé, Hunter Hoffman, Christine G. Springer, Justin Sprenkle, Gordon Powers, Haiyan Jiang, Sherry L. La Porte, Rajkumar Ganesan, Sanjaya Singh, Adam Zwolak
Abstract
Generation of bispecific antibodies (BsAbs) having two unique Fab domains requires heterodimerization of the two heavy chains and pairing of each heavy chain with its cognate light chain. An alternative bispecific scaffold (Bipod) comprising an scFv and a Fab on a heterodimeric Fc eliminates the possibility of light chain mispairing. However, unpredictable levels of chain expression and scFv-induced aggregation can complicate purification and reduce the yield of desired Bipod. Here, we describe a high-throughput method for generation of Bipods based on protein A and CH1 domain affinity capture. This method exploits over-expression of the scFv chain to maximize heterodimer yield. Bipods purified by this method have purity suitable for cell-based functional assays and in vivo studies.