Dr. William Gradishar Reviews the Eribulin 301 Study

William J. Gradishar, MD, Director, Maggie Daley Center for Women's Cancer Care, Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, describes results from the 301 Study that compared eribulin mesylate (Halaven) to capecitabine in patients with locally advanced or metastatic breast cancer following treatment with anthracyclines or taxanes.

In the phase III trial, 1102 patients were randomized 1:1 to receive eribulin or capecitabine as a first-, second-, or third-line treatment. The trial sought to prove that eribulin was superior to capecitabine at improving progression-free survival (PFS) and overall survival (OS), Gradishar notes.

Gradishar explains that when examining the Kaplan-Meier curves from the study a clear overlap between the two arms can be observed. Overall, the median OS was 15.9 month for eribulin compared to 14.5 months with capecitabine (HR = 0.879; P = 0.056). The PFS for eribulin compared to capecitabine was respectively 4.1 compared to 4.2 months (HR = 1.079; P = 0.305).

In subset analyses, patients with HER2-negative and triple-negative breast cancer seemed to benefit from treatment with eribulin, Gradishar points out. In HER2-negative patients the OS was 15.9 months for eribulin compared to 13.5 months for capecitabine (HR = 0.838; P = 0.030).

Gradishar believes these results indicate that eribulin is equal to capecitabine. This is meaningful, since eribulin is often used as a salvage therapy while capecitabine is commonly administered in earlier lines of treatment for metastatic breast cancer.