CTLA4 and melanoma: In the sub-study 02A of the KEYMAKER-U02, 200 patients with PD-1 refractory melanoma are randomized to receive vibostolimab (MK-7684), a TIGIT blocking humanized IgG1 monoclonal antibody, or lenvatinib with pembrolizumab and quavonlimab (anti-CTLA-4) (NCT04305041).