- No more than one prior systemic therapeutic regimen for unresectable stage III or stage IV melanoma; this includes chemotherapy, biologic therapy, biochemotherapy, or investigational treatment; this does not include any therapies given in the adjuvant setting; however, patients are excluded if they have a history of prior treatment for melanoma (either adjuvant or metastatic disease) with ipilimumab or other cytotoxic T-lymphocyte antigen 4 (CTLA-4) inhibitor, or prior interferon-alpha treatment for metastatic disease (history of adjuvant interferon-alpha is allowed); there should be a 4-week washout period between last treatment administration and initiation of study therapy