Retrospective analysis of Japanese patients with relapse or refractory small-cell lung cancer treated with amrubicin hydrochloride.

Amrubicin (AMR) is one of the most active chemotherapeutic agents for small-cell lung cancer (SCLC). Previous phase II studies reported on its effectiveness and severe hematological toxicities. However, AMR has yet to be approved outside Japan. Subsequently, no extensive evidence of its effects exist. Between January 2004 and October 2009, 69 patients received AMR for relapsed SCLC at our hospital. We reviewed these patients, and analyzed the efficacy and hematological toxicities of AMR. There were 27 sensitive relapses (S) and 42 refractory relapses (R). Patients received platinum agents, and 43 and 71% of the patients received etoposide and irinotecan, respectively. The median number of treatment cycles was 3 (range 1-14), and the response rate was 51% (70% in the S and 38% in the R cases, respectively). In patients administered with AMR as second-line therapy, the response rate was 55% and as third-line therapy, 39%. Median progression-free survival time was 3.2 months in the S and 1.9 months in the R patients (p=0.1071). Median survival time from the start of AMR was 6.2 months in the S and 4.8 months in the R cases (p=0.0045). The frequency of grade ≥3 hematological toxicities was leukopenia (41%), neutropenia (51%), anemia (14%), thrombocytopenia (17%) and febrile neutropenia (12%). No treatment-related death was observed. Although hematological toxicities, particularly neutropenia, were severe, AMR showed excellent anti-tumor activity, not only in the S, but also in the R cases, as shown in previous phase II studies. These results warrant further evaluation of AMR in the second-line setting, and also in the first-line setting in both limited- and extensive-stage disease. We conducted a phase II study to assess the efficacy of consolidation chemotherapy with AMR after standard chemoradiation in limited-stage SCLC.