Eribulin Plus Gemcitabine (EG) vs Paclitaxel Plus Gemcitabine (PG) in HER2-Negative Metastatic Breast Cancer

Metastatic breast cancer (MBC) is an incurable disease and is needed to improve effective chemotherapy. Paclitaxel plus Gemcitabine (PG) combination chemotherapy is one of the preferred chemotherapeutic regimens for patients with MBC, and was found to be proper as a maintenance chemotherapy regimen with survival benefit and feasible toxicity profile as shown in a large phase III KCSG (Korean Cancer Study Group) study (Park Y et al. J Clin Oncol 31(14):1732, 2013). Eribulin mesylate is a microtubule-targeting agent that showed improved overall survival benefit as monotherapy for MBC patients as a new chemotherapeutic agent after failure of anthracycline and taxane in EMBRACE study (Cortes J et. al. Lancet 377:914-923, 2011). Eribulin was also reported its promising efficacy in another randomized phase III study that demonstrated eribulin as efficacious as capecitabine (Kaufman P et. al. Abstr# S6-6, SABCS 2012). Both study results showed potential clinical benefit in patients with triple negative MBC (TNBC). Thus, eribulin combined with gemcitabine may be a new potential regimen for early line therapy in patients with metastatic breast cancer. Furthermore, eribulin may have rational benefit compared with paclitaxel in terms of neurotoxicity. Although there is no direct evidence that eribulin has better neurotoxicity profile than taxane, eribulin tended to show less neurotoxicity compared with ixabepilone in a phase II trial (Vahdat, L et al. 2011 SABCS). Eribulin has no worsen toxicity as compared to paclitaxel. Therefore, EG may have less neurotoxicity comparing to PG. In phase I trial, eribulin in combination with gemcitabine was feasible in patients with advanced solid tumor treated with chemotherapy (\< 3 lines) (Goel R, et al, 2009 ASCO). Based on this rationale, the investigators are to conduct randomized phase II study comparing EG chemotherapy with PG chemotherapy for patients with HER-2 negative MBC as first-line chemotherapy. A total of 118 patients wi