Abstract
Programmed cell death protein 1 (PD-1) plays a significant role in suppressing antitumor immune responses. Cancer treatment with immune checkpoint inhibitors (ICIs) targeting PD-1 has been approved to treat numerous cancers and is the backbone of cancer immunotherapy. Anti-PD-1 molecule is necessary for next-generation cancer immunotherapy to further improve clinical efficacy and safety as well as integrate into novel treatment combinations or platforms. We developed a highly efficient hybridoma generation and screening strategy to generate high-potency chimeric anti-PD-1 molecules. Using this strategy, we successfully generated several mouse hybridoma and mouse/human chimeric clones that produced high-affinity antibodies against human PD-1 with high-quality in vitro PD-1/PD-L1 binding blockade and T cell activation activities. The lead chimeric prototypes exhibited overall in vitro performance comparable to commercially available anti-PD-1 antibodies and could be qualified as promising therapeutic candidates for further development toward immuno-oncology applications.