Results of a randomized phase II trial of amrubicin (AMR) versus topotecan (Topo) in patients with extensive-disease small cell lung cancer (ED-SCLC) sensitive to first-line platinum-based chemotherapy

Abstract

8028 Background: SCLC presents as ED-SCLC in 60%-70% of patients (pts). AMR, a synthetic anthracycline, is approved for these pts in Japan. We compare the efficacy and safety of single-agent AMR vs topotecan in non-Japanese pts with 2nd-line ED-SCLC sensitive to 1st-line platinum-based chemotherapy. Methods: This phase II, open-label, multicenter study enrolled pts with ED-SCLC sensitive to 1st-line platinum-based chemotherapy (recurrence or progression ≥90 days from 1st-line treatment). Pts aged ≥18 years with ECOG performance status (PS) ≤2 and only 1 prior therapy were eligible. Pts were randomized (2:1) to receive IV AMR 40 mg/m2/d (d, 1–3) or IV topotecan 1.5 mg/m2/d (d 1–5) and treated every 21 days until progression, unacceptable toxicity, or withdrawal. The primary endpoint, overall response rate (ORR, complete + partial response), used RECIST criteria. Secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. Results: In all, 76 pts were randomized to AMR (n=50) or topotecan (n=26) with AMR given for a median of 6 cycles (range 1–16) and topotecan 3 cycles (1–16). AMR significantly improved ORR rates vs topotecan (p<0.012; Table ). Median PFS/OS was 4.3 months (95% CI 2.0, 6.1)/9.3 months (95% CI 5.7, 12.0) with AMR vs 3.5 months (95% CI 2.1, 6.3)/8.9 months (95% CI 4.8, 13.8) with topotecan. There was a higher proportion of ECOG PS 2 pts in the AMR group (n=6) vs the topotecan group (n=2). A trend towards improved OS was observed in the ECOG 0–1 subgroup of 68 pts: median OS was 10.5 months with AMR vs 9.7 months with topotecan. The most common grade ≥3 adverse events with AMR vs topotecan were neutropenia (53% vs 74%), thrombocytopenia (31% vs 52%) and leukopenia (27% vs 30%). Three AMR pts (6%) and 1 topotecan pt (4%) died of neutropenic infection. Conclusions: AMR significantly improves ORR and has acceptable tolerability as 2nd-line treatment in pts with sensitive ED-SCLC. [Table: see text] [Table: see text]