Eribulin is also being evaluated for use earlier in patients with breast cancer, in both the metastatic and adjuvant settings, in three studies described at the San Antonio meeting.

In a phase II study of eribulin as first-line treatment for locally recurrent or metastatic HER2-negative breast cancer in 48 patients, response rates were 27% overall, 29% for the estrogen receptor–positive subset, and 30% for the triple-negative subset; disease control rates were 75%, 83%, and 60%, respectively.¹ Overall, 30 patients (62%) experienced a grade 3/4 treatment-related or treatment-emergent adverse event, most commonly alopecia, neutropenia, and fatigue. The most common grade 3/4 toxicity was neutropenia, which occurred in 50% of patients.

In a phase II trial of 40 HER2-positive patients with locally recurrent or metastatic disease, eribulin given concurrently with trastuzumab produced responses in 55% of patients, and the disease control rate was 92%.² Duration of response in the 22 responders was 204 days. For all treated patients, median progression-free survival was 9.2 months.

In the adjuvant setting, investigators are testing the benefit of adding eribulin following dose-dense doxorubicin and cyclophosphamide.³ Fifty-five patients were enrolled, but the investigators determined that the regimen conferred an unacceptable risk for neutropenia. The study was amended to include a cohort who will follow a regimented growth factor protocol, to improve the feasibility of the treatment. ■

References

1. Vahdat L, Schwartzberg L, Gluck S, et al: Results of a phase 2, multicenter, single-arm study of eribulin lmesylate as first-line therapy for locally recurrent or metastatic HER2-negative breast cancer. 2012 San Antonio Breast Cancer Symposium. Abstract P1-12-02. Presented December 11, 2012.

2. Vahdat L, Schwartzberg L, Wilks S, et al: Eribulin mesylate + trastuzumab as first-line therapy for locally recurrent or metastatic HER2-positive breast cancer: Results from a phase 2, multicenter, single-arm study. 2012 San Antonio Breast Cancer Symposium. Abstract P5-20-04. Presented December 13, 2012.

3. Cadoo K, Fornier M, Lake DE, et al: Adjuvant treatment of early-stage breast cancer with eribulin mesylate following dose-dense doxorubicin and cyclophosphamide: Preliminary results from a phase 2, single-arm feasibility study. 2012 San Antonio Breast Cancer Symposium. Abstract P1-13-11. Presented December 11, 2012.