Gemcitabine and Imatinib Mesylate in Treating Patients With Recurrent or Metastatic Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS: Histologically confirmed non-small cell cancer Recurrent disease after adjuvant treatment OR progressive disease after 1 prior treatment for recurrent or metastatic disease Received at least 1 prior chemotherapy regimen and meets the following criteria: No more than 1 prior chemotherapeutic regimen in the recurrent or metastatic setting Patients who received prior chemotherapy in the adjuvant setting are eligible when 1 of the following criteria is met: In first recurrence (after 1 prior regimen) Received first-line chemotherapy in the recurrent setting after 2 prior regimens Measurable disease Must have ≥ 1 measurable target lesion outside prior radiotherapy field OR radiologic confirmation of disease progression within a prior radiotherapy field No known or untreated brain metastases or carcinomatous meningitis Clinically stable, treated brain metastases allowed provided it has been > 7 days since prior steroids PATIENT CHARACTERISTICS: ECOG performance status 0-1 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 contraception during and for 3 months after completion of study treatment Able to swallow oral medication No concurrent medical condition that would preclude study compliance No history of allergic reaction to compounds of similar chemical or biological composition to gemcitabine hydrochloride or imatinib mesylate No uncontrolled illness that would preclude study compliance, including any of the following: Symptomatic congestive heart failure Unstable angina pectoris Cardiac arrhythmia requiring therapy Myocardial infarction within the past 6 months Active infection No New York Heart Association class III-IV congestive heart failure No chronic liver disease (i.e., chronic active hepatitis, cirrhosis) No HIV positivity No other primary malignancies within the past 5 years, except carcinoma in situ of the cervix or nonmelanoma skin cancer PRIOR CONCURRENT THERAPY: See Disease Characteristics At least 3 weeks since prior chemotherapy (6 weeks for nitrosoureas) At least 3 weeks since prior anti-vascular endothelial growth factor therapy and recovered At least 3 weeks since prior radiotherapy and recovered More than 28 days since prior and no other concurrent investigational or commercial agents More than 2 weeks since prior major surgery No prior gemcitabine hydrochloride or imatinib mesylate for metastatic disease No prior tyrosine kinase inhibitor, except for gefitinib or erlotinib hydrochloride No concurrent therapeutic warfarin (prophylactic warfarin therapy ≤ 1 mg daily allowed) No other concurrent medications that would preclude study compliance No concurrent chronic systemic corticosteroids