Phase II trial to study the effectiveness of imatinib mesylate in treating patients who have recurrent small cell lung cancer. Imatinib mesylate may stop the growth of cancer cells by blocking the enzymes necessary for cancer cell growth.

PRIMARY OBJECTIVES:

I. Determine the response rate, time to progression, and overall survival of patients with recurrent small cell lung cancer treated with imatinib mesylate.

II. Correlate the presence of c-Kit mutations in tumor tissue with treatment response in patients treated with this drug.

III. 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.

Inclusion Criteria:

• 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

• Performance status - ECOG 0-2

• Absolute neutrophil count at least 1,500/mm^3

• Platelet count at least 100,000/mm^3

• Hemoglobin at least 9 g/dL

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

• Direct bilirubin no greater than ULN

• Creatinine no greater than 1.5 times ULN

• 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

• 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

• See Disease Characteristics

• More than 3 weeks since prior chemotherapy

• More than 2 weeks since prior radiotherapy

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

  • Concurrent whole-brain radiotherapy for CNS progression allowed

• More than 3 weeks since prior major surgery

• No prior imatinib mesylate