DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed transitional cell carcinoma of the bladder, ureter, or renal pelvis

  • Advanced or metastatic disease

• Measurable disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan

  • The following are not considered measurable disease:

    • Bone lesions
    • Leptomeningeal disease
    • Ascites
    • Pleural/pericardial effusion
    • Inflammatory breast disease
    • Lymphangitis cutis/pulmonis
    • Abdominal masses not confirmed and followed by imaging techniques
    • Cystic lesions
• Tumor accessible for biopsy
• No known brain metastases

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-1 OR
• Karnofsky 70-100%

Life expectancy

• More than 3 months

Hematopoietic

• WBC ≥ 3,000/mm^3
• Absolute neutrophil count ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3
• No bleeding diathesis

Hepatic

• Bilirubin normal
• AST and ALT ≤ 2.5 times upper limit of normal (ULN)

Renal

• Creatinine < 1.5 times ULN OR
• Creatinine clearance ≥ 45 mL/min

Cardiovascular

• No myocardial infarction within the past 6 months
• No congestive heart failure
• No unstable angina pectoris
• No active cardiomyopathy
• No unstable ventricular arrhythmia
• No other cardiac arrhythmia
• No uncontrolled hypertension

Gastrointestinal

• No active peptic ulcer disease
• No malabsorption syndrome
• No gastrointestinal (GI) tract disease that would preclude ability to take oral medication
• No uncontrolled inflammatory GI disease (e.g., Crohn's disease or ulcerative colitis)
• No requirement for IV alimentation
• Able to swallow and retain oral medication

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No ongoing or active serious infection
• No uncontrolled psychotic disorders
• No psychiatric illness or social situation that would preclude study compliance
• No other active malignancy within the past 5 years except adequately treated carcinoma in situ or nonmelanoma skin cancer
• No history of allergic reaction attributed to compounds of similar chemical or biological composition to sorafenib
• No other uncontrolled illness
• No other serious medical condition that would preclude study treatment

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• At least 4 weeks since prior chemotherapy (including adjuvant or neoadjuvant chemotherapy)

  • At least 6 weeks for nitrosoureas or mitomycin

Endocrine therapy

• Not specified

Radiotherapy

• More than 4 weeks since prior radiotherapy
• No concurrent radiotherapy to the sole site of measurable disease

Surgery

• No prior surgical procedures affecting absorption

Other

• No prior systemic therapy for advanced or metastatic disease

• At least 7 days since prior and no concurrent administration of any of the following:

  • Rifampin
  • Phenytoin
  • Carbamazepine
  • Phenobarbital
  • Hypericum perforatum (St. John's wort)
• No other concurrent investigational agents
• No other concurrent anticancer therapy

• No concurrent therapeutic anticoagulation

  • Concurrent prophylactic anticoagulation (i.e., low-dose warfarin) allowed provided requirements for PT, INR, or PTT are met
• No concurrent combination anti-retroviral therapy for HIV-positive patients