SCH 66336 Plus Gemcitabine in Treating Patients With Advanced Cancer of the Urinary Tract

DISEASE CHARACTERISTICS: Histologically confirmed metastatic or unresectable primary transitional cell carcinoma of the urinary tract, including bladder, ureter, and renal pelvis At least one measurable lesion 20 mm or greater by conventional techniques OR 10 mm or greater by spiral CT scan Must have received one (and only one) prior chemotherapy regimen for advanced or metastatic disease No clinical signs of brain metastases PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: At least 3 months Hematopoietic: Absolute neutrophil count at least 2,000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin less than 1.5 times upper limit of normal (ULN) Alkaline phosphatase and transaminases no greater than 2.5 times ULN (no greater than 5 times ULN with liver metastases) Renal: Creatinine no greater than 1.7 mg/dL Cardiovascular: Normal cardiac function No ischemic heart disease within the past 6 months Normal 12 lead ECG Other: No prior gastrectomy or any gastrointestinal disease that may impair absorption of SCH 66336 No unstable systemic disease No active uncontrolled infection No psychological, familial, sociological, or geographical condition that would preclude study No prior or concurrent other malignancy except cone biopsied carcinoma in situ of the cervix or adequately treated basal or squamous cell skin cancer Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: See Disease Characteristics At least 4 weeks since prior chemotherapy No prior farnesyl protein transferase inhibitors or gemcitabine Endocrine therapy: Not specified Radiotherapy: At least 4 weeks since prior radiotherapy Surgery: At least 2 weeks since prior major surgery Other: No other concurrent anticancer agents No other concurrent investigational therapy