ERIBULIN APPROVED BY FDA FOR LATE STAGE BREAST CANCER

November 16, 2010 — The US Food and Drug Administration (FDA) approved eribulin mesylate injection (Halaven; Eisai, Inc) yesterday for the treatment of metastatic breast cancer in patients who have received at least 2 prior chemotherapy regimens for late-stage disease.

Eribulin is a synthetic analog of halichondrin B, a novel microtubule dynamics inhibitor extracted from the marine sponge Halichondria okadia.

FDA approval was based on data from a phase 3 study of 762 women with metastatic breast cancer who had been heavily pretreated with a median of 4 chemotherapy regimens that included an anthracycline and a taxane.

As previously reported by Medscape Medical News, results showed that eribulin significantly improved overall survival compared with a treatment of physician's choice (13.12 vs 10.65 months; Δ, 2.47 months; hazard ratio, 0.81; P = .041). The 1-year survival rate was 53.9% for eribulin-treated patients and 43.7% for those given other drugs.

"There are limited treatment options for women with aggressive forms of late-stage breast cancer who have already received other therapies," said Richard Pazdur, MD, director of the Office of Oncology Drug Products in the FDA's Center for Drug Evaluation and Research, in an agency news release. "Halaven shows a clear survival benefit and is an important new option for women."

Adverse events most commonly reported in eribulin-treated study patients included neutropenia, anemia, leukopenia, alopecia, fatigue, nausea, asthenia, peripheral neuropathy, and constipation.

Other FDA-approved therapeutic options for the treatment of refractory, metastatic breast cancer include capecitabine tablets (Xeloda; Hoffmann-LaRoche, Inc) for disease resistant to paclitaxel and anthracycline-based chemotherapy; ixabepilone infusion (Ixempra; Bristol-Myers Squibb Co) for late-stage disease resistant to an anthracycline, taxane, and capecitabine; and a combination of capecitabine and ixabepilone for disease resistant to anthracycline- and taxane-based chemotherapy.