Disease	Breast cancer
Stage of Disease/Treatment	Neoadjuvant
Prior Therapy	None
Type of Study	Phase II, randomized
Primary Endpoint	Complete response rate
Secondary Endpoint	Event‐free survival
Additional Details of Endpoints or Study Design
At the time of the first interim futility analysis, 8 (30.8%) of the 26 patients in the paclitaxel group and 1 (4.8%) of the 21 patients in the eribulin group had achieved a pCR (Table 2). The test statistic was $\frac{(0.048-0.308)}{\sqrt{\mathit{p}(1-\mathit{p})(\frac{1}{21}+\frac{1}{26})}}=-2.25$, where p = (1 + 8)/(21 + 26) and it crossed the futility stopping boundary. In an exploratory analysis (not preplanned) comparing outcomes by breast cancer molecular subtype, we found that among the 34 patients with hormone receptor–positive disease, 3 of 18 (17%) in the paclitaxel group and 0 of 16 (0%) in the eribulin group achieved a pCR. Among the 13 patients with triple‐negative breast cancer, 4 of 8 (50%) in the paclitaxel group and 1 of 5 (20%) in the eribulin group achieved a pCR. For each disease subtype, the difference in pCR rate between the paclitaxel and eribulin groups was not significant.
Investigator's Analysis
The combination of eribulin and FAC/FEC was not superior to paclitaxel and FAC/FEC and was associated with higher hematological toxicity; therefore, we do not recommend eribulin/FAC/FEC as a standard neoadjuvant therapy in early‐stage breast cancer.