INTRODUCTION: The aim of this study was to evaluate efficacy of maintenance sunitinib after first-line chemotherapy for stage IIIB/IV NSCLC. METHODS: Cancer and Leukemia Group B 30607 trial was a randomized, double-blind, placebo-controlled, phase III study that enrolled patients without progression after four cycles of first-line platinum-based doublet chemotherapy with or without bevacizumab. Bevacizumab was allowed only during the four cycles of chemotherapy. Patients were randomized to receive sunitinib, 37.5 mg/d, or placebo and were treated until unacceptable adverse event(s), progression, or death. The primary end point was progression-free survival (PFS). RESULTS: A total of 210 patients were enrolled, randomized, and included in the intent-to-treat analysis. Ten patients did not receive maintenance therapy (four who received placebo and six who received sunitinib). Grade 3/4 adverse events affecting more than 5% of the patients were fatigue (25%), thrombocytopenia (12%), hypertension (12%), rash (11%), mucositis (11%), neutropenia (7%), and anemia (6%) for sunitinib and none for placebo. There were three grade 5 events in patients receiving sunitinib (one pulmonary hemorrhage, one other pulmonary event, and one death not associated with a Common Terminology Criteria for Adverse Events term) and two grade 5 events in patients receiving placebo (one other pulmonary event and one thromboembolism). Median PFS was 4.3 months for sunitinib and 2.6 months for placebo (hazard ratio = 0.62, 95% confidence interval: 0.47-0.82, p = 0.0006). Median overall survival was 11.7 months for sunitinib versus 12.1 months for placebo (hazard ratio = 0.98, 95% confidence interval: 0.73-1.31, p = 0.89). CONCLUSIONS: Maintenance sunitinib was safe and improved PFS as maintenance therapy in stage IIIB/IV NSCLC but had no impact on overall survival. There is no room for future investigations of sunitinib in this setting.