DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed renal cell carcinoma

  • Metastatic disease OR unresectable primary tumor
  • No known curative therapy exists
• Documented progressive renal cell carcinoma as defined by RECIST criteria within the past 6 months
• Measurable disease with ≥ 1 unidimensionally measurable lesion

• No known symptomatic brain metastasis or untreated brain metastases or carcinomatous meningitis

  • Treated brain metastasis allowed provided the following criteria are met:

    • Clinically stable
    • More than 7 days since prior steroids

PATIENT CHARACTERISTICS:

• ECOG performance status 0-2
• Life expectancy ≥ 3 months
• Absolute neutrophil count ≥ 1,500/mm³
• Platelet count ≥ 100,000/mm³
• Bilirubin ≤ 1.5 times upper limit of normal (ULN)
• AST and ALT ≤ 2.5 times ULN
• Creatinine ≤ 1.5 times ULN OR creatinine clearance ≥ 60 mL/min
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective nonhormonal contraception during and for 3 months after completion of study treatment
• Must be able to swallow oral medication
• No coexisting medical condition that would preclude study compliance
• No history of allergic reaction to compounds of similar chemical or biological composition to gemcitabine hydrochloride and/or imatinib mesylate
• No uncontrolled illness that would preclude study participation
• No symptomatic congestive heart failure
• No unstable angina pectoris
• No cardiac arrhythmia requiring therapy
• No myocardial infarction within the past 6 months
• No active infection
• No other malignancy within the past 5 years except carcinoma in situ of the cervix or nonmelanoma skin cancer
• No New York Heart Association class III-IV congestive heart failure
• No known chronic liver disease (i.e., chronic active hepatitis or cirrhosis)
• No known HIV positivity
• No significant history of noncompliance to medical regimens

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• Recovered from all prior therapy

• No more than 3 prior treatment regimens, including any of the following:

  • No more than 1 prior cytotoxic therapy
  • Immunotherapy regimens comprising interferon and/or aldesleukin
  • Therapy with molecular targets
  • Any combination of the above treatments to a maximum of 3 total therapies
• No prior gemcitabine hydrochloride for metastatic disease
• No prior imatinib mesylate for metastatic disease
• More than 2 weeks since prior major surgery
• At least 3 weeks since prior chemotherapy (6 weeks for nitrosoureas)
• At least 3 weeks since prior anti-vascular endothelial growth factor therapy

• At least 3 weeks since prior radiotherapy

  • Must have evidence of ≥ 1 measurable target lesion outside the radiation fields OR radiologically confirmed disease progression within the radiation fields after completion of radiotherapy
• At least 28 days since prior and no other concurrent investigational or commercial agents, unless disease is rapidly progressing

• No concurrent therapeutic warfarin

  • Concurrent low molecular weight heparin or heparin allowed for therapeutic anticoagulation
  • Concurrent prophylactic warfarin therapy ≤ 1 mg daily to maintain catheter patency allowed
• No concurrent filgrastim (G-CSF) for prevention of neutropenia
• No other concurrent chemotherapy, immunotherapy, hormonal cancer therapy, radiation therapy, or cancer surgery
• No concurrent routine use (i.e., daily or every other day) of systemic corticosteroid therapy (in supraphysiologic doses)
• No concurrent medication that would preclude study compliance