Eisai has been boosted by new data which confirms that its marine-derived drug Halaven significantly improves overall survival in women with in women with late-stage breast cancer.

Data from the 762-patient Phase III EMBRACE trial has been published in The Lancet and demonstrates that Halaven (eribulin) significantly improved overall survival compared with treatment of physician’s choice (TPC) in women with metastatic breast cancer previously treated with at least an anthracycline and a taxane. TPC is defined as any single-agent chemotherapy, hormonal treatment or biologic approved for  cancer, palliative treatment or radiotherapy.

Specifically, EMBRACE met its primary endpoint, demonstrating a statistically significant increase in OS for Halaven compared with TPC of 2.5 months (13.1 vs 10.6 months respectively). The drug, which was approved by the US Food and Drug Administration last November, had a "predictable and manageable side effect profile" with the most common adverse events in both arms being fatigue (53.7% with Halaven, 39.7% with TPC) and neutropaenia (51.7% vs 29.6%).

Javier Cortes of Vall d'Hebron University Hospital in Barcelona and lead investigator for EMBRACE, noted that there is "an urgent need for therapies with a proven survival benefit for women with metastatic breast cancer who have already received multiple treatments". He added that "this is a remarkable step forward in this treatment setting where previously overall survival has been considered an endpoint difficult to attain”._

Uday Bose, head of institutional care at Eisai Europe, said the data "open the door for a new treatment strategy in Europe, and one that will benefit patients who previously had very limited options". The company recently received a positive opinion from the European Medicines Agency's Committee for Medicinal Products for Human Use for Halaven, and approval is expected shortly.

Observers believe that Halaven, which belongs to a class of antineoplastic agents, the halichondrins, that are derived from the marine sponge Halichondria okadai, has the potential to be a blockbuster and soften the impact on earnings Eisai is going to suffer from the loss of US patent protection on its Alzheimer's disease drug Aricept (donepezil).