PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent myeloid colony stimulating factors Chemotherapy: At least 12 months since prior adjuvant or neoadjuvant chemotherapy and recovered Endocrine therapy: Not specified Radiotherapy: See Disease Characteristics At least 4 weeks since prior radiotherapy and recovered Surgery: At least 4 weeks since prior surgery and recovered Other: No prior systemic therapy (including investigational agents) for metastatic bladder cancer At least 4 weeks since prior intravesical therapy and recovered At least 30 days since prior participation in other investigational drug trial No concurrent intravesical therapy No other concurrent therapy for cancer