First-Line Gemcitabine, Cisplatin + Ipilimumab for Metastatic Urothelial Carcinoma

OUTLINE: This is a multi-center study Gemcitabine 1000 mg/m2 Days 1 \& 8 Cisplatin 70 mg/m2 Day 1 Ipilimumab 10 mg/kg Day 1 (start cycle 3) Treatment during the induction phase will be administered in six 21-day cycles. During cycles 1 and 2, gemcitabine plus cisplatin will be administered WITHOUT ipilimumab. During cycles 3-6, combination therapy with gemcitabine, cisplatin, plus ipilimumab will be administered. Patients without evidence of disease progression (by irRC) after completion cycle 6 will continue single-agent ipilimumab maintenance every 3 months. Karnofsky performance status (KPS) ≥ 80% within 14 days prior to registration for protocol therapy. Life Expectancy: Not Specified Hematopoietic: * White blood cell count (WBC) ≥ 3.5K/mm3 * Hemoglobin (Hgb) ≥ 9 g/dL * Platelets ≥ 100K/mm3 * Absolute neutrophil count (ANC) ≥ 1.5k/mm3 Hepatic: * Bilirubin ≤ 1.5 times x Upper Limit of Normal (ULN) (except patients with Gilbert's Syndrome, who must have a total bilirubin less than 3.0 mg/dL) * Aspartate aminotransferase (AST, SGOT) ≤ 2.5 x ULN. NOTE: If the patient has liver metastases present, then ≤ 5 x ULN Renal: * Calculated creatinine clearance of ≥ 55 cc/min using the Cockcroft-Gault formula Cardiovascular: Not Specified