Breast cancer drug shows improved survival

Eribulin mesylate (E7389), Eisai's treatment for heavily pre-treated metastatic breast cancer patients, has been shown to improve median overall survival (OS) significantly compared with Treatment of Physician's Choice (TPC), according to results of a phase III study presented at the American Society of Clinical Oncology (ASCO) annual meeting.

Eribulin, a synthetic analogue of halichondrin B (derived from a marine sponge), is a non-taxane, microtubule dynamics inhibitor.

The open-label, randomised, multicentre EMBRACE study was designed to compare overall survival in patients treated with eribulin versus a TPC arm. The study enrolled 762 patients with locally recurrent or metastatic breast cancer who were previously treated with between two and five prior chemotherapies. Patients were randomised 2:1 to receive either eribulin or TPC.

Patients who received eribulin had a median overall survival of 13.12 months, compared with 10.65 months for TPC. This represents an improvement in median overall survival of 2.5 months for patients treated with eribulin compared with TPC. Treatment-emergent serious adverse events were reported in 25 per cent of patients in the eribulin arm and 25.9 per cent of patients in the TPC.

EMBRACE is the first single-agent phase III trial to demonstrate improved survival against a variety of other agents in this patient population. In March, Eisai submitted applications for eribulin in the treatment of locally advanced or metastatic breast cancer to regulatory authorities in the EU, Japan and the US.