Safety Study of IL-21/Ipilimumab Combination in the Treatment of Melanoma

For more information regarding BMS clinical trial participation, please visit www.BMSStudyConnect.com. Inclusion Criteria: * Unresectable Stage III or Stage IV melanoma * Part 1 Dose Escalation: Prior melanoma treatment allowed except for the following: ipilimumab, BMS-982470 (rIL-21), anti-Programmed Death-1 (anti-PD-1), anti-programmed death-ligand 1 (anti-PD-L1), anti-PD-L2 or anti-CD137 * Part 2 Cohort expansion: Prior treatment for melanoma is not allowed, except for adjuvant therapy with interferon alpha or melanoma vaccines which are permitted * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Measurable disease by computed tomography (CT) or magnetic resonance imaging (MRI) * Normal liver function tests Exclusion Criteria: * Part 1 Dose escalation: subjects with ≤ 2 brain metastases of stable size, ≥ 4 weeks post-radiation treatment, and off steroids are allowed * Part 2 Cohort expansion: subjects with known or suspected brain metastases and uveal melanoma are excluded * Autoimmune disease