This is a Phase 3, multi-national, open-label, 2-arm randomized study in patients with surgically incurable metastatic melanoma who have received no prior chemotherapy, or biochemotherapy for the treatment of metastatic disease. The primary objective of this trial is to compare overall survival for patients with advanced melanoma who are randomized to receive CP-675,206 with that of patients who are randomized to receive either dacarbazine or temozolomide (investigator choice)

Inclusion Criteria:

• Surgically incurable melanoma, either Stage IV or IIIC with N3 status for regional lymph nodes and in-transit or satellite lesions.
• Serum lactic acid dehydrogenase (LDH) <= 2 x ULN
• ECOG performance status of 0 or 1

Exclusion Criteria:

• Received any systemic therapy for metastatic melanoma except post-surgical adjuvant treatment with cytokines (eg, alpha-interferon or GM-CSF) or with vaccines after complete resection of melanoma.
• History of brain metastases