ctx-471

CTX-471 is a fully human monoclonal IgG4 antibody that acts as an agonist of CD137 (also known as 4-1BB or tumor necrosis factor receptor superfamily member 9). It binds to a distinct epitope on CD137 with intermediate affinity, resulting in optimal receptor agonism and improved activation of T-cells and natural killer (NK) cells. This mechanism enhances anti-tumor immunity by stimulating immune effector functions. Preclinical studies have shown potent monotherapy activity against multiple tumor models, including those resistant to immune checkpoint inhibitors, and the generation of long-term immunological memory. In clinical trials, CTX-471 has demonstrated promising anti-tumor activity in patients with advanced solid tumors who have progressed on approved PD-1 or PD-L1 inhibitors, including durable responses in small cell lung cancer, melanoma, and mesothelioma. The drug is being developed both as monotherapy and in combination with other immunotherapies such as pembrolizumab[1][2][3][6][9].