Used in immunotherapy to enhance anti-tumor immune responses by blocking the LAG-3 (Lymphocyte Activation Gene-3) receptor on T cells. This inhibition prevents the downregulation of T-cell activity, allowing the immune system to more effectively recognize and attack cancer cells. Favezelimab is primarily investigated in combination with other checkpoint inhibitors, such as anti-PD-1 antibodies, for the treatment of advanced solid tumors including melanoma, non-small cell lung cancer, and other malignancies. It supports immune reactivation in the tumor microenvironment and is part of clinical development for improving durable response rates in cancer patients.