Patients receive nivolumab intravenously (IV) over 30 minutes on days 1, 15, 29, 43, 57, and 71 of course 1 and on days 1 and 15 of course 2, over 60 minutes on days 29 and 57 of course 2 and on days 1, 29, and 57 of subsequent courses. Patients also receive ipilimumab over 90 minutes on days 1 and 43. Courses repeat every 84 days in the absence of disease progression, unexpected toxicity, or withdrawal of consent.