This randomized phase III trial studies sunitinib malate to see how well it works when given as maintenance therapy (meaning it is approved for treatment after chemotherapy) in patients with stage IIIB-IV non-small cell lung cancer who have responded to prior treatment with combination chemotherapy. Sunitinib malate may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth and by blocking the growth of new blood vessels necessary for tumor growth. It is not yet known whether sunitinib malate is effective in helping tumors continue to shrink or stop growing.

PRIMARY OBJECTIVES: I. To evaluate the effect of sunitinib (sunitinib malate) compared to placebo on progression-free survival (PFS) in advanced non-small cell lung cancer (NSCLC) patients who have had either stable or responding disease over the course of their initial 4 cycles of platinum-based therapy. SECONDARY OBJECTIVES: I. To evaluate the toxicity of sunitinib compared to placebo in the maintenance setting. II. To evaluate the additional response rate as a result of sunitinib in this setting. III. To assess the impact of sunitinib on overall survival compared to the placebo arm. IV. To assess the impact of sunitinib on delaying the time to deterioration in quality of life and symptom progression compared to placebo using the European Organization for Research and Treatment of Cancer (EORTC) Core Quality of Life Questionnaire (QLQ-C30) and Lung Cancer Module (LC13). V. To assess vascular endothelial growth factor (VEGF) haplotypes in advanced non-small cell lung cancer and sunitinib maintenance. OUTLINE: Patients are randomized to 1 of 2 treatment arms. ARM I: Patients receive sunitinib malate orally (PO) once daily (QD) on days 1-21. Courses repeat every 21 days in the absence of disease progression or unacceptable toxicity. ARM II: Patients receive placebo PO QD on days 1-21. Courses repeat every 21 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 3 months for 1 year, every 6 months for 1 year, and then periodically for 3 years.