 Patients will receive CP-675,206 at 15 mgkg administered intravenously on day 1 of every 90-day cycle for up to 4 cycles or until disease progression or intolerance of toxicity. Each cycle is defined as a 90 - 4 days period. Patients should be weighed within 10 days prior to each cycle and the administered dose of CP-675,206 should be recalculated. 