Among the 39 melanoma phase I trials employing double checkpoint blockade, there are combinations with HDACi, IDOi, etc., but 15/39 melanoma studies involve additional immune stimulatory drugs such as cytokines (hu14.18-IL2, NKTR-214 IL-2, IL-15) or vaccine-like stimulatory agonistic antibodies (anti-OX40, anti-GITR, anti-ICOS). Here, ICOS is linked to melanoma.