Randomized phase 3 study of maintenance therapy with S-1 plus best supportive care (BSC) versus BSC alone after induction therapy with carboplatin plus S-1 for advanced or relapsed squamous cell lung carcinoma (WJOG7512L)

e20531 Background: Our previous phase 3 study established carboplatin plus the oral fluorinated pyrimidine formulation S-1 as a standard option for first-line treatment of advanced non–small cell lung cancer (NSCLC) (J Clin Oncol 2010; 28:5240). The importance of maintenance therapy for patients with advanced squamous NSCLC has been unknown, however. Methods: WJOG7512L was designed as a randomized phase 3 study to evaluate whether maintenance therapy with S-1 improves clinical outcome after induction therapy with carboplatin plus S-1 in such patients. Before randomization, patients received carboplatin (AUC of 5 on day 1 every 3 weeks) plus S-1 (40 mg/m2 twice per day on days 1 to 14 every 3 weeks) as induction therapy. Those who did not progress after four cycles of induction therapy were randomized to receive either S-1 plus best supportive care (BSC) or BSC alone. The primary objective was to confirm the superiority of S-1 plus BSC with regard to progression-free survival. Results: Of the 365 patients enrolled, 347 participated in the induction phase and 131 of these individuals were randomized to receive S-1 plus BSC ( n = 67) or BSC alone ( n = 64). Baseline demographics and clinical characteristics of the subjects, including the response to induction therapy, were well balanced. Patients receiving S-1 plus BSC showed a significantly reduced risk of disease progression compared with those receiving BSC alone (hazard ratio [HR], 0.548; 95% confidence interval [CI], 0.374–0.802; P = 0.0019). Median overall survival from randomization did not differ significantly between the two arms: 17.8 months for BSC alone and 16.7 months for S-1 plus BSC (HR, 0.890; 95% CI, 0.583–1.357). Time to deterioration in quality of life also showed no significant difference ( P = 0.8754 for FACT-TOI, P = 0.9016 for FACT-LCS). The incidence of adverse events during maintenance therapy was low, with neutropenia, anemia, and thrombocytopenia of grade 3 or 4 each occurring in ~1% to 4% of patients. Conclusions: Maintenance with S-1 plus BSC is an effective and well-tolerated treatment option for patients with advanced squamous NSCLC. Clinical trial information: UMIN000010396.