RATIONALE: Imatinib mesylate may stop the growth of cancer cells by blocking the enzymes necessary for cancer cell growth.

PURPOSE: Phase II trial to study the effectiveness of imatinib mesylate in treating patients who have recurrent small cell lung cancer.

OBJECTIVES:

• Determine the response rate, time to progression, and overall survival of patients with recurrent small cell lung cancer treated with imatinib mesylate.
• Correlate the presence of c-Kit mutations in tumor tissue with treatment response in patients treated with this drug.
• Correlate individual patient variation in clinical (toxicity and/or activity), pharmacologic (pharmacokinetic/pharmacodynamic parameters), and/or biologic (correlative laboratory study results) responses to this drug with genetic differences in proteins involved in drug response (transport, metabolism, and/or mechanism of action).

OUTLINE: This is a multicenter study. Patients are stratified according to length of prior therapy (less than 3 months vs at least 3 months).

Patients receive oral imatinib mesylate twice daily for 28 days. Courses continue in the absence of disease progression or unacceptable toxicity.*

Patients are followed every 3 months until disease progression and then every 6 months for up to 3 years after registration.

NOTE: *Patients who develop CNS metastasis as the only site of disease progression receive therapeutic whole-brain radiotherapy and then resume study therapy.

PROJECTED ACCRUAL: A total of 41 patients for stratum I will be accrued within 21 months and 50 patients for stratum II will be accrued within 25 months for this study.

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed small cell lung cancer (SCLC)

  • No mixed histology
• Must have received only 1 prior treatment regimen (e.g., cyclophosphamide, doxorubicin, and vincristine alternating with etoposide and cisplatin allowed)
• c-Kit positive by immunohistochemistry (at least 1+)

• At least 1 unidimensionally measurable lesion

  • Longest diameter at least 20 mm

• No uncontrolled CNS metastasis

  • Treated CNS metastasis allowed

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2

Life expectancy

• Not specified

Hematopoietic

• Absolute neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3
• Hemoglobin at least 9 g/dL

Hepatic

• Total bilirubin no greater than 1.5 times upper limit of normal (ULN) OR
• Direct bilirubin no greater than ULN

Renal

• Creatinine no greater than 1.5 times ULN

Cardiovascular

• No unstable angina pectoris
• No uncontrolled congestive heart failure within the past 3 months unless ejection fraction is greater than 40%
• No myocardial infarction within the past 3 months

Other

• No uncontrolled infection
• No other malignancy within the past 3 years except skin cancer or localized prostate cancer
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for at least 3 months after study participation

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• See Disease Characteristics
• More than 3 weeks since prior chemotherapy

Endocrine therapy

• Not specified

Radiotherapy

• More than 2 weeks since prior radiotherapy

• No concurrent radiotherapy (including palliative therapy for bone pain)

  • Concurrent whole-brain radiotherapy for CNS progression allowed

Surgery

• More than 3 weeks since prior major surgery

Other

• No prior imatinib mesylate

• National Cancer Institute (NCI)
• Cancer and Leukemia Group B