A phase III study comparing amrubicin and cisplatin (AP) with irinotecan and cisplatin (IP) for the treatment of extended-stage small cell lung cancer (ED-SCLC): JCOG0509.

Abstract

7003 Background: IP is the standard treatment for ED-SCLC, however often cause severe diarrhea. AP have shown promising activity in SCLC with fewer diarrhea. We conducted a phase III trial comparing AP with IP. Methods: Eligibility criteria included patients (pts) with chemotherapy-naïve, ED-SCLC, aged 20 to 70, and ECOG PS 0-1. Pts were randomized to receive either IP or AP, balancing for site, sex, and PS. IP comprised administration of I (60 mg/m2) iv on days 1, 8, and 15, and P (60 mg/m2) iv on day1,every 4 weeks. AP comprised administration of A (40 mg/m2) iv on day 1-3, and P (60 mg/m2) iv on day1, every 3 weeks. The planned sample size was 141 pts in each arm with a one-sided alpha of 5% and power of 70% and a non-inferiority margin of hazard ratio (HR) as 1.31. The primary endpoint was overall survival (OS). The secondary endpoints were response rate (RR), progression-free survival (PFS), adverse events (AEs), and quality of life (QOL). We evaluated pts’ QOL twice: at the baseline and after completion of the second course. Results: 284 pts were randomized to IP (n=142) and AP (n=142). Median age was 63, 84% were male, and 56% had PS 0. When 191pts enrolled, more febrile neutropenia (FN) was observed in AP than anticipated, and the initial dose of A was decreased from 40 mg/m2 to 35 mg/m2. At the second interim analysis conducted after the completion of patient accrual, the median OS of AP (15.0 m) was much worse than that of IP (18.3 m) and the HR (1.41; 96.3% CI, 1.03-1.93) exceeds even the non-inferiority margin, so the Data and Safety Monitoring Committee recommended early publication of the results. Median PFS was 5.7 (IP) vs. 5.2 months (AP) (HR 1.43, 95% CI, 1.13-1.82). RR was 69.5% (IP) vs. 77.9% (AP) (p=0.14). AEs in IP and AP arm were Grade 4 neutropenia (22.5% vs. 78.6%), G3-4 FN (10.7% vs. 32.1%), and G3-4 diarrhea (7.1% vs.1.4%). Proportion of improvement in physical status of QOL was 37.1%(IP) vs. 31.7%(AP), (odds ratio 0.72; 95%CI, 0.43-1.22; P=0.227). Conclusions: AP showed more bone marrow suppression than expected although it caused less diarrhea. The non-inferiority of AP to IP was not demonstrated and IP remains the standard treatment for ED-SCLC.