At the 2015 American Society of Clinical Oncology (ASCO) Annual Meeting, Paolo A. Ascierto, MD, of Istituto Nazionale Tumori IRCCS “Fondazione G. Pascale”, Naples, Italy, discusses CheckMate 067, a randomised, double-blind, phase 3 trial of nivolumab monotherapy or nivolumab combined with ipilimumab versus ipilimumab monotherapy in patients with previously untreated unresectable or metastatic melanoma.