FL-302 is a tetravalent bispecific antibody in preclinical development targeting both Claudin18.2 and CD137 (4-1BB). FL-302 enhances the activation and function of T cells through the CD137 agonism specifically in the region of CLDN18.2+ tumor cells. This presents an opportunity to improve on the efficacy and safety of early Claudin18.2 and CD137 antibodies when used alone or in combination with other immunotherapies.
The role of CD137 (4-1BB) in immune activation
CD137 (4-1BB) is a co-stimulatory receptor expressed on T cells and other immune cells. Agonistic antibodies against CD137 have been shown to result in increased T-cell proliferation, activation and differentiation, resulting in an anti-tumor response. By targeting CD137 activity specifically to regions where Claudin18.2 is expressed, FL-302 was designed to enhance the anti-tumor effect and minimize toxicity as compared to prior CD137 antibodies.