Correlation between the efficacy of amrubicin and the previous chemotherapy regimen for relapsed small cell lung cancer

Amrubicin has been demonstrated to be beneficial in the treatment of patients with relapsed small cell lung cancer (SCLC). The aim of the present study was to evaluate whether there is a significant difference in the efficacy of amrubicin between patients with relapsed SCLC who were previously treated with a platinum agent in combination with a topoisomerase I inhibitor, and those patients previously treated with a platinum agent in combination with a topoisomerase II inhibitor. The medical records of patients with SCLC, who were diagnosed as having relapsed following treatment with a platinum-based regimen and subsequently received amrubicin monotherapy, were retrospectively reviewed. Of a total of 48 patients with SCLC who were treated with amrubicin, the overall response rate, median progression-free survival (PFS) time and median survival time (MST) were determined to be 31.3%, 7.1 and 17.0 months, respectively. The response rate, PFS time and MST did not differ significantly between the patients treated previously with a platinum agent in combination with irinotecan, a topoisomerase I inhibitor, (36.4%, 5.7 and 11.4 months, respectively) and those treated previously with a platinum agent in combination with etoposide, a topoisomerase II inhibitor (30.0%, 4.7 and 14.8 months, respectively). The results indicate that amrubicin may be effective as a second-line chemotherapeutic agent for patients with SCLC, irrespective of which platinum agent and topoisomerase inhibitor-based chemotherapy regimen was previously administered.

Randomized Phase III Trial of Amrubicin Versus Topotecan As Second-Line Treatment for Patients With Small-Cell Lung Cancer

Purpose

Amrubicin, a third-generation anthracycline and potent topoisomerase II inhibitor, showed promising activity in small-cell lung cancer (SCLC) in phase II trials. This phase III trial compared the safety and efficacy of amrubicin versus topotecan as second-line treatment for SCLC.

Patients and Methods

A total of 637 patients with refractory or sensitive SCLC were randomly assigned at a ratio of 2:1 to 21-day cycles of amrubicin 40 mg/m2 intravenously (IV) on days 1 to 3 or topotecan 1.5 mg/m2 IV on days 1 to 5. Primary end point was overall survival (OS); secondary end points included overall response rate (ORR), progression-free survival (PFS), and safety.

Results

Median OS was 7.5 months with amrubicin versus 7.8 months with topotecan (hazard ratio [HR], 0.880; P = .170); in refractory patients, median OS was 6.2 and 5.7 months, respectively (HR, 0.77; P = .047). Median PFS was 4.1 months with amrubicin and 3.5 months with topotecan (HR, 0.802; P = .018). ORR was 31.1% with amrubicin and 16.9% with topotecan (odds ratio, 2.223; P < .001). Grade ≥ 3 treatment-emergent adverse events in the amrubicin and topotecan arms were: neutropenia (41% v 54%; P = .004), thrombocytopenia (21% v 54%; P < .001), anemia (16% v 31%; P < .001), infections (16% v 10%; P = .043), febrile neutropenia (10% v 3%; P = .003), and cardiac disorders (5% v 5%; P = .759); transfusion rates were 32% and 53% (P < .001), respectively. NQO1 polymorphisms did not influence safety outcomes.

Conclusion

Amrubicin did not improve survival when compared with topotecan in the second-line treatment of patients with SCLC. OS did not differ significantly between treatment groups, although an improvement in OS was noted in patients with refractory disease treated with amrubicin.

Review of the management of relapsed small-cell lung cancer with amrubicin hydrochloride

Lung cancer is the leading cause of cancer death, and approximately 15% of all lung cancer patients have small-cell lung cancer (SCLC). Although second-line chemotherapy can produce tumor regression, the prognosis is poor. Amrubicin hydrochloride (AMR) is a synthetic anthracycline anticancer agent and a potent topoisomerase II inhibitor. Here, we discuss the features of SCLC, the chemistry, pharmacokinetics, and pharmacodynamics of AMR, the results of in vitro and in vivo studies, and the efficacy and safety of AMR monotherapy and combination therapy in clinical trials. With its predictable and manageable toxicities, AMR is one of the most attractive agents for the treatment of chemotherapy-sensitive and -refractory relapsed SCLC. Numerous studies are ongoing to define the applicability of AMR therapy for patients with SCLC. These clinical trials, including phase III studies, will clarify the status of AMR in the treatment of SCLC.