This is a prospective randomized multicenter trial for evaluation of the biological response modifier Factor AF2 in advanced urothelial cancer treated with chemotherapy. Main aim of the study was the analysis of supportive effects. Additionally patients were examined with regard to tumor response, time to progression and survival. 106 patients with advanced urothelial cancer received chemotherapy with cisplatin and methotrexate. They were randomized for additional Factor AF2 (500 mg i.v., given at days 0-3, 7-10 and 11-14). Myelotoxicity was more common and severe in the group without Factor AF2 reaching statistical significance. Gastrointestinal side effects occurred in both groups, though grade III to IV toxicity was more common without Factor AF2. Overall remission rate was 38%, median survival 33 weeks, mean time to progression 20 weeks. There was no significant difference between the two groups with or without Factor AF2.