Amrubicin monotherapy for elderly patients with previously treated lung cancer

Phase II study of Amrubicin monotherapy in elderly or poor-risk patients with extensive disease of small cell lung cancer

Background Previous study indicated that an optional anti-cancer drug for the treatment of small-cell lung cancer (SCLC) is amrubicin. However, no prospective studies have evaluated amrubicin in chemo-naive elderly or poor-risk patients with SCLC. Therefore, this study aimed to evaluate the efficacy of amrubicin as first-line chemotherapy for elderly or poor-risk patients with extensive-disease SCLC (ES-SCLC). Methods Patients with chemotherapy-naive ES-SCLC received multiple cycles of 40 mg/m² amrubicin for 3 consecutive days every 21 days. The primary endpoint was the overall response rate (ORR), and the secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. Results Between March 2011 and August 2015, 36 patients were enrolled in this study. Each patient received a median of four treatment cycles (range, 1-6 cycles). ORR was 52.8% [95% confidence interval (CI), 37-69%]. The median PFS and OS periods were 5.0 months (95% CI, 3.4-6.6 months) and 9.4 months (95% CI, 5.2-13.6 months), respectively. Neutropenia was the most common grade 3 or 4 adverse event (69.4%), with febrile neutropenia developing in 13.9% of patients. No treatment-related death occurred. At the time of starting second-line chemotherapy, 19 of 22 patients (86%) had significantly improved or maintained their performance status (PS) relative to their PS at the time of starting amrubicin monotherapy as first-line chemotherapy (P = 0.027). Conclusions The results of the present study suggest that amrubicin could be considered as a viable treatment option for chemotherapy-naive elderly or poor-risk patients with ES-SCLC (Clinical trial registration number: UMIN000011055 www.clinicaltrials.gov ).

Medical treatment of small cell lung cancer: state of the art and new development

INTRODUCTION

Small cell lung cancer (SCLC) is a rapidly progressive disease that accounts for approximately 15% of all lung cancers. Chemotherapy remains the cornerstone of treatment of SCLC, but in the last two decades, its progress has reached a plateau. Although a significant sensitivity to chemotherapy and radiotherapy is a feature of SCLC, an early development of drug resistance unavoidable occurs during the course of the disease. Second-line treatment for relapsed patients remains a very challenging setting, with a limited clinical benefit.

AREAS COVERED

A thorough analysis of various therapeutic strategies reported in literature for SCLC treatment was performed. This review includes novel therapeutic approaches such as maintenance or consolidation treatments, new chemotherapy agents and targeted therapy.

EXPERT OPINION

Against this background, there is a desperate need for the development of novel active drugs. Among these, amrubicin has also shown more favourable antitumor activity, and is the most promising at present. Concerning targeted agents, these have failed to demonstrate effectiveness for SCLC and a better understanding of the molecular mechanisms is clearly needed. In the future, further investigations are required to clarify the role of novel anti-angiogenic or pro-apoptotic agents and hedgehog pathway inhibitors.

C609T polymorphism of NAD(P)H quinone oxidoreductase 1 as a predictive biomarker for response to amrubicin

INTRODUCTION

Amrubicin is a promising agent in the treatment of lung cancer, but predictive biomarkers have not yet been described. NAD(P)H:quinone oxidoreductase 1 (NQO1) is an enzyme known to metabolize amrubicinol, the active metabolite of amrubicin, to an inactive compound. We examined the relationship between NQO1 and amrubicinol cytotoxicity.

METHODS

Gene and protein expression of NQO1, amrubicinol cytotoxicity, and C609T single-nucleotide polymorphism of NQO1 were evaluated in 29 lung cancer cell lines: 14 small cell lung cancer (SCLC) and 15 non-SCLC (NSCLC). The involvement of NQO1 in amrubicinol cytotoxicity was evaluated by small interfering RNA against NQO1.

RESULTS

A significant inverse relationship between both gene and protein expression of NQO1 and amrubicinol cytotoxicity was found in all cell lines. Treatment with NQO1 small interfering RNA increased amrubicinol cytotoxicity and decreased NQO1 expression in both NSCLC and SCLC cells. Furthermore, cell lines genotyped homozygous for the 609T allele showed significantly lower NQO1 protein expression and higher sensitivity for amrubicinol than those with the other genotypes in both NSCLC and SCLC cells.

CONCLUSIONS

NQO1 expression is one of the major determinants for amrubicinol cytotoxicity, and C609T single-nucleotide polymorphism of NQO1 could be a predictive biomarker for response to amrubicin treatment.