Discovery and Humanization of High Affinity Therapeutic Antibodies Against Transmembrane Proteins
Therapeutic antibodies targeting type 1 transmembrane proteins (T1P) are among the most successful biologic drugs yet developed. Monoclonal antibody OKT3, which targets T cell-expressed T1P CD3, became the first approved antibody therapeutic in 1986 and was used to prevent graft rejection. Blinatumomab, which binds CD3 as well as CD19, was the first approved bispecific T cell engager (BITE, approved in 2014) and is used to treat leukemia. Nivolumab and Pembrolizumab (both approved in 2014) were the first immune checkpoint antagonist mAbs to target T1P PD-1 and are used to treat various cancers. For the next generation of therapeutic mAbs targeting transmembrane proteins, a reliable and robust mAb discovery and humanization workflow is paramount. Here we describe an effective hybridoma-based antibody discovery and humanization approach for a T1P target using Penta Mice immunization to obtain mAbs with picomolar binding potency and affinity and human/pig/cyno (preclinical species) cross- reactivity.