Gemcitabine With or Without Imatinib Mesylate in Treating Patients With Metastatic or Unresectable Kidney Cancer

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