Inclusion Criteria

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