PDCD1 and melanoma: The 02A sub-study (NCT04305041) randomizes patients with PD-1 refractory melanoma to receive vibostolimab (MK-7684) (anti-TIGIT), pembrolizumab and quavonlimab (anti-CTLA-4); pembrolizumab, quavonlimab and lenvatinib; or pembrolizumab and ATRA.