OBJECTIVES: I. Determine the objective response rate (complete or partial) and duration of response of patients with small cell lung cancer who have had at least a partial response to one prior chemotherapy regimen for at least 3 months when treated with R115777. II. Determine the time to disease progression, survival, and quality of life in this patient population treated with this drug. III. Assess the safety of R115777 in this patient population. IV. Assess the presence of ras mutations in relapsed patients with available paraffin blocks.