CStone Pharmaceuticals announced that the preclinical data of multi-specific antibody CS2006/NM21-1480 has been presented at the American Association for Cancer Research (AACR) Annual Meeting 2022. CS2006/NM21-1480 is a monovalent, tri-specific antibody-based molecule targeting PD-L1, 4-1BB, and human serum albumin (HSA). CS2006/NM21-1480 represents a leading class of broadly acting next-generation anti-PD-1/PD-L1 cancer immunotherapies and a new backbone molecule for tumor-specific combination therapies.

CS2006/NM21-1480 is designed to bind to the immune co-stimulatory receptor 4-1BB and conditionally activate T cells only when engaging and blocking the checkpoint receptor ligand PD-L1 on the surface of tumor cells, potentially preventing the liver toxicities observed with previous anti-4-1BB agonistic antibodies. Compared to other PD-L1/4-1BB bispecific antibody candidates, CS2006/NM21-1480's unique monovalent structure and ultra-high-affinity PD-L1-binding are designed to tap the synergistic potential of tumor-localized modulation of PD-L1 and 4-1BB. Furthermore, half-life extension via the HSA-binding is designed to enable convenient dosing schedules for patients.

CS2006/NM21-1480 is anticipated to be effective against tumors with a wide range of PD-L1 expression levels and may overcome primary and/or acquired resistance to anti-PD-1/PD-L1 therapies. CS2006/NM21-1480 was discovered and engineered by Numab Therapeutics ("Numab"), the company's partner, using its proprietary ?cap™ technology and MATCH™ platform. The company and Numab signed an exclusive regional licensing agreement for the development and commercialization of the drug candidate.

Pursuant to the terms of the licensing agreement, the company will fund the research and development of CS2006/NM21-1480 up to completion of an initial Phase 1b clinical trial. In exchange, the company obtains exclusive rights from Numab to develop and commercialize CS2006/NM21-1480 in Greater China (including Mainland China, Hong Kong, Macau, and Taiwan), South Korea, and Singapore. Numab retains all CS2006/NM21-1480 rights for the rest of the world.

Upon completion of the company's funding period, no further financial obligations will be owed by either party.