Clinical outcome of amrubicin therapy according to the prior chemotherapy sensitivities of extensive small cell lung cancer.

Background: Amrubicin (AMR) is an active agent for relapsed small cell lung cancer (SCLC). However, the activity of AMR in refractory relapsed patients is controversial. The objective of this retrospective analysis was to evaluate the efficacy and safety of AMR as second-line chemotherapy in SCLC, especially refractory relapsed SCLC.

Methods: Between July 2003 and February 2009, a total of 27 patients were treated with AMR at a dosage of 40 mg x m(-2) x day(-1) on days 1-3 every 3 weeks. Safety was assessable for all patients. Efficacy was evaluated in 26 patients (one patient was not assessable for response), in 12 patients with chemotherapy-sensitive relapse and 14 patients with chemotherapy-refractory relapse. Sensitive relapse means that a first-line response lasted more than 90 days. Refractory relapse means that either did not respond to first-line chemotherapy or responded initially but relapsed within 90 days.

Results: Thirteen patients (50%, 95% CI, 31% to 69%) had partial response, including 6 (50%) of the 12 patients with chemotherapy-sensitive relapse and 7 (50%) of 14 patients with chemotherapy-refractory relapse. Median survival times of patients with chemotherapy-sensitive and -refractory relapse were 9.7 months and 8.4 months, respectively, showing significant difference (p = 0.0337). Adverse events were observed in all 27 patients. Grade 3 and 4 neutropenia was seen in 8 patients (29.6%) and 15 patients (55.5%), respectively. Grade 3 and 4 thrombocytopenia occurred in 10 patients (37.0%) and 2 patients (7.4%). Non-hematologic toxicities were generally mild, except for febrile neutropenia. Febrile neutropenia was seen in 6 patients (22.2%). No treatment-related deaths occurred.

Conclusions: AMR is an active agent for the treatment of relapsed SCLC, especially chemotherapy-refractory relapse SCLC, with predictable and manageable toxicities.