Background: The role of cisplatin-based chemotherapy for the treatment of locally advanced or metastatic urothelial carcinoma is well established. For patients (pts) who cannot receive cisplatin owing to renal insufficiency, substitution with carboplatin was associated with inferior response rate and overall survival (OS). To address this unmet need, we conducted a phase II study of gemcitabine (Gem), paclitaxel (Tax), and doxorubicin (Adria) in this group. Methods: The primary endpoint was overall response rate (ORR); secondary endpoints were toxicity, OS, and the safety and efficacy of pegfilgrastim 6 mg (G-CSF) given immediately after chemotherapy on Day 1. A Simon 2-stage design was chosen to detect ORR of 40% and to reject ORR of 25%. Eligible pts had metastatic or unresectable urothelial carcinoma, no prior chemotherapy, performance status ≤ 2, glomerular filtration < 60 ml/min, and no need for dialysis; all gave informed consent. Brain metastases were excluded, as were clinically significant heart disease, peripheral neuropathy, and liver or bone marrow dysfunction. Treatment consisted of 900 mg/m² Gem (fixed rate of 10 mg/m²/min), 135 mg/m² Tax, and 40 mg/m² Adria administered with same-day GCSF every 14 d to a maximum of 9 cycles. Tumors were evaluated after every 3 cycles. Results: Forty pts were enrolled January 2008 through November 2011, and 39 could be assessed for response. Median age was 72 (range, 51–89) and 11 pts (28.2%) were women. There were 7 complete and 15 partial responses, for an ORR of 56.4% (95% CI 39.6-72.2). Notable grade 3 and 4 nonhematologic toxicities in the first 2 cycles were dyspnea and mucositis (1 pt each). There were no treatment-related deaths and no toxicity attributed to same-day G-CSF. Median OS was 14.4 mo with median follow-up of 12.6 mo for all pts, 15.6 mo for 10 who were alive. Conclusions: Gem-Tax-Adria is effective as first-line treatment for metastatic or locally advanced urothelial carcinoma, and it can safely be given to pts with renal insufficiency. Same-day G-CSF also appears to be safe and effective in this setting. Phase III study is warranted. Clinical trial information: NCT00478361.