The drug eribulin significantly improved survival among women with recurrent or metastatic breast cancer, “challeng[ing] the notion that improved overall survival is an unrealistic expectation during evaluation of new anticancer therapies in the refractory setting,” according to researchers (Lancet. 2011;377:914-923).
In the phase 3 open-label trial of the Eisai Metastatic Breast Cancer Study Assessing Physician’s Choice Versus E7389 (EMBRACE) investigation (funded by Eisai), 508 women were randomly assigned to “E7389,” or eribulin mesilate. This nontaxane inhibitor of microtubule dynamics is a synthetic analogue of halichondrin B, which is isolated from a marine sponge. An additional 254 women were assigned to a treatment of physician’s choice (TPC). All participants had undergone two to five chemotherapy regimens previously (two or more for advanced disease).
Overall survival was significantly improved in the eribulin group (median 13.1 months) compared with the TPC group (10.6 months). The most common adverse events in both sets of patients were asthenia or fatigue and neutropenia. Peripheral neuropathy was the most common adverse event leading to discontinuation of eribulin; this occurred in 24 (5%) of 503 women.
Dr. Javier Cortes of Vall d’Hebron University Hospital and Vall d’Hebron Institute of Oncology in Barcelona, Spain, and EMBRACE co-investigators concluded that eribulin showed a significant and clinically meaningful improvement in overall survival compared with TPC in women with heavily pretreated metastatic breast cancer. They also pointed out that “This global phase 3 study establishes a potential new standard treatment for women with heavily pretreated metastatic breast cancer, for whom there was previously no chemotherapy treatment with proven survival benefit.”