DISEASE CHARACTERISTICS:

* Histologically confirmed transitional cell carcinoma (TCC) of the urothelium (bladder, renal pelvis, ureter, or urethra) not curable by surgery or radiotherapy

* Any T, N0-3, M1 or unresectable M0
* Poorly differentiated TCC, predominant TCC with rare foci of squamous differentiation, or rare foci of adenocarcinoma allowed
* Measurable disease

* At least 1 lesion accessible for biopsy
* Soft tissue disease that has been irradiated within the past 2 months not considered measurable disease
* Progressive or recurrent disease after only 1 prior systemic chemotherapy regimen for advanced disease
* No adenocarcinoma, small cell carcinoma, sarcoma, squamous cell carcinoma, or mixed histology

PATIENT CHARACTERISTICS:

Age:

* Any age

Performance status:

* Zubrod 0-2

Life expectancy:

* Not specified

Hematopoietic:

* Platelet count at least 100,000/mm3
* Absolute granulocyte count at least 1,200/mm3

Hepatic:

* Bilirubin no greater than 1.5 times upper limit of normal (ULN)
* SGOT no greater than 2 times ULN

Renal:

* Creatinine no greater than 2 times ULN

Other:

* No other prior malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, or adequately treated stage I or II cancer currently in complete remission
* Not pregnant or nursing
* Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

* No concurrent filgrastim (G-CSF)

Chemotherapy:

* See Disease Characteristics
* No prior adjuvant chemotherapy
* At least 28 days since prior chemotherapy and recovered

Endocrine therapy:

* Not specified

Radiotherapy:

* See Disease Characteristics
* At least 28 days since prior radiotherapy and recovered

Surgery:

* See Disease Characteristics
* At least 28 days since prior surgery and recovered

Other:

* No prior systemic therapy between biopsy and study entry
* At least 28 days since prior intravesical therapy and recovered
* No concurrent agents that induce CYP3A4 (e.g., nafcillin, rifampin, carbamazepine, phenobarbital, phenytoin, or St. John's Wort)