Clinical evaluation of eribulin mesylate for the treatment of metastatic breast cancer]

Eribulin mesylate, a novel non-taxane inhibitor of microtubule dynamics, results in a significant improvement in the overall survival of heavily pretreated patients with metastatic breast cancer(MBC). In the present study, we aimed to clarify the efficacy and safety of eribulin mesylate for the treatment of MBC.We examined 18 patients with MBC who received eribulin mesylate in our hospital from October 2011 to May 2013. The patients were assessed for therapeutic response and adverse events with this treatment; in addition, these parameters were assessed in patients undergoing a combination treatment of eribulin mesylate and trastuzumab.The mean age of the patients in this study was 68.7 years(range, 60-85 years). All patients exhibited metastases to lymph nodes and distant sites. The mean number of prior regimens was 4.4(range, 2-9). The mean number of cycles of eribulin mesylate treatment administered was 7.2(range, 2- 17). The objective response rate and clinical benefit rate(PR+long SD)were 33.3%(6/18)and 50.0%(9/18), respectively, and the median progression-free survival was 6 months. The Grade 3/4 adverse events occurring in the patients included neutropenia in 13 patients(72.2%), anemia in 1 patient(5.6%), anorexia in 1 patient(5.6%), stomatitis in 1 patient(5.6%), and peripheral neuropathy in 1 patient(5.6%). However, 3 elderly patients who received the combination treatment of trastuzumab and eribulin mesylate experienced no adverse events.eribulin mesylate appears to demonstrate an acceptable tumor response in patients with MBC, and it can be safely administered to elderly patients if myelosuppression is carefully managed.