CTX-8371 / PD-1 x PD-L1

CTX-8371 is a common light chain-based, bispecific antibody targeting the checkpoint receptor PD-1 and its ligand PD-L1. Discovered via an unbiased screen of bispecifics targeting checkpoint combinations using our StitchMabsTM platform, CTX-8371 enhances T cell activation and tumor cell killing in vitro and in vivo with significantly increased potency compared to Keytruda and other approved PD-1/PDL-1 therapies. Mechanistic studies suggest that the enhanced efficacy is due to a unique ability of this bispecific to drive PD-1 downregulation in T cells. Due to its common light chain-based molecular structure, CTX-8371 is highly manufacturable with expression, purity, stability, and pharmacokinetics essentially identical to a monoclonal antibody.