Ipilimumab With or Without High-Dose Recombinant Interferon Alfa-2b in Treating Patients With Stage III-IV Melanoma That Cannot Be Removed by Surgery

Inclusion Criteria: * Patients must have unresectable stage III or stage IV melanoma, either initial presentation or recurrent, that is of cutaneous origin or unknown primary origin and that is histologically diagnosed * 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 * Patients must have Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 * Patients must not have other significant medical, surgical, or psychiatric conditions or require any medication or treatment that in the opinion of the investigator may interfere with compliance, make the administration of ipilimumab or HDI hazardous or obscure the interpretation of adverse events (AEs), such as a condition associated with frequent diarrhea; patients must not have an active infection requiring current treatment with parenteral antibiotics * Patients must not have a history of infl…