ARM D: Patients receive induction high-dose ipilimumab IV over 90 minutes on day 1. Treatment repeats every 21 days for a total of 4 courses in the absence of disease progression or unacceptable toxicity. Beginning on week 24, patients receive maintenance high-dose ipilimumab IV over 90 minutes on day 1. Treatment repeats every 90 days for a maximum of 4 courses in the absence of disease progression or unacceptable toxicity.