Randomized phase 2 study comparing irinotecan versus amrubicin as maintenance therapy after first-line induction therapy for extensive disease small cell lung cancer (HOT1401/NJLCG1401)

Background: A cisplatin plus irinotecan (CPT-11) regimen is used for patients with extensive disease small cell lung cancer (ED-SCLC). Amrubicin (AMR) is primarily used for relapsed SCLC. The HOT1401/NJLCG1401 trial, an open-label randomized phase II trial, was designed to assess the benefit of maintenance therapy in patients with ED-SCLC who responded to induction therapy. Methods: Patients with histologically- or cytologically-confirmed ED-SCLC were included and were treated with an induction therapy of four cycles of cisplatin (60 mg/m² on day 1) plus CPT-11 (60 mg/m² on days 1, 8, and 15) every four weeks. After induction therapy, patients who had nonprogressive disease were randomized to receive either maintenance CPT-11 (60 mg/m² on days 1 and 8) every three weeks, or AMR (35 mg/m² on days 1–3) every three weeks. Results: A total of 34 patients were enrolled; 20 patients had progressive disease or received incomplete induction chemotherapy. Finally, 14 patients were randomly assigned to receive CPT-11 (n = 7) or AMR (n = 7). This study was terminated prematurely because of low patient accrual. The overall objective response rate was 73%, the median PFS was 5.7 months (95% confidence interval [CI]: 3.6–11.8), and the median overall survival was 20.1 months (95% CI: 13.7–not reached). No statistically significant difference in progression-free survival (PFS) were noted between patients treated with CPT-11 and those treated with AMR. There were no treatment-related deaths in this study. Conclusions: Maintenance therapy with CPT-11 or AMR after induction therapy might be effective in some patients.