Clinical Benefits of and Recent Progress in Eribulin Mesylate Therapy for Breast Cancer Patients

Abstract

Metastatic breast cancer is difficult to completely cure with currently available drug therapy, and the main treatment goals are prolongation of survival and improvement of the quality of life (QOL). Eribulin mesylate (eribulin) is a synthetic analogue of halichondrin B. Because eribulin selectively binds with highly affinity to only microtubule plus ends, a small number of molecules can exert antitumor effect through microtubule inhibition. A phase Ⅲ randomized clinical trial (Study 305) was performed in 762 women with locally recurrent or metastatic breast cancer who had previously received 2 to 5 regimens of chemotherapy, including an anthracycline and a taxane. On independent review of the results, the median OS was found to be significantly longer in patients who received eribulin than in those who received treatment of physician’s choice. To our knowledge, no single anticancer agent has been demonstrated to significantly prolong OS in patients with metastatic breast cancer who previously received chemotherapeutic regimens including anthracyclines and taxanes. In addition, new randomized clinical trials are ongoing to evaluate eribulin monotherapy and eribulin in combination with other anticancer agents and to compare eribulin monotherapy with monotherapy with other anticancer agents. New clinical trials of eribulin monotherapy and combined therapy are expected to further clarify the clinical benefits of eribulin in patients with metastatic and primary breast cancer. We expect that eribulin will be shown to be clinically beneficial, thereby contributing to further progress in the treatment of breast cancer.