• To assess safety and tolerability during and for 1 hour following a 15 mg/kg dose of CP 675,206 administered as a one hour infusion. [ Time Frame: Last patient dosed = 05Dec2008 ] [ Designated as safety issue: No ]
  

• •To identify potential relationships between polymorphisms in the Cytotoxic T lymphocyte associated antigen 4 (CTLA4), Fcgamma receptor IIa (FcgRIIa), IgG2a genes with safety and/or immune response of subjects treated with CP 675,206 [ Time Frame: Last PG obtained = estimated 05Dec2008 ] [ Designated as safety issue: No ]
  
• •To evaluate the overall safety and tolerability of CP 675,206 in this population [ Time Frame: Last patient dosed = estimated 05Dec2008 ] [ Designated as safety issue: No ]
  
• •To characterize the pharmacokinetics (PK) of CP 675,206 following a one hour infusion [ Time Frame: Last PK timepoint obtained =estiamted 04Sep2009 ] [ Designated as safety issue: No ]
  
• •To monitor for human anti human (HAHA) response to CP 675,206 [ Time Frame: Last HAHA time point obtain =estimated 05Dec2008 ] [ Designated as safety issue: No ]
  
• •To assess evidence of anti tumor activity as measured by best overall response rate using Response Evaluation Criteria in Solid Tumors (RECIST) criteria, duration of response, progression free survival [ Time Frame: Last RECIST obtained = estimated 04Sep2009 ] [ Designated as safety issue: No ]
  

Inclusion Criteria:

• Histologically confirmed melanoma that is surgically incurable Note: Prior therapies for melanoma, including cancer vaccines, are permitted but are not required. There is no limit to the number of prior regimens for melanoma a patient may have received.
• Evidence of at least one lesion
• Eastern Cooperative Oncology Group (ECOG) performance status 0-1
• CT scan of the brain with contrast or MRI of the brain within 6 weeks prior to enrollment showing no evidence of active brain metastases. PET scans and PET/CT scans are also acceptable.

Exclusion Criteria:

• Previous treatment with other anti CTLA4 agents (eg, ipilimumab, MDX 010).
• Previously randomized to Pfizer study A3671009: A Phase 3, Open Label, Randomized Comparative Study of CP 675,206 and Either Dacarbazine or Temozolomide in Patients with Advanced Melanoma.
• History of chronic autoimmune disease (eg, Addison's disease, multiple sclerosis, Graves disease, Hashimoto's thyroiditis, psoriasis, rheumatoid arthritis, systemic lupus erythematosus, hypophysitis, etc.).
• History of inflammatory bowel disease (eg, Crohn's disease or ulcerative colitis), celiac disease, or other chronic gastrointestinal conditions associated with diarrhea, or current acute colitis of any origin, and any history of diverticulitis (even a single episode) or evidence of diverticulitis at baseline, including evidence limited to CT scan only.
• Brain metastases that have not been adequately treated with surgery or stereotactic radiosurgery and have not been stable at least 3 months prior to enrollment.