Randomized Multicenter Phase II Trial of Neoadjuvant Therapy Comparing Weekly Nab-paclitaxel Followed by FEC With Docetaxel Followed by FEC in HER2 - Early-stage Breast Cancer.

BACKGROUND: Weekly nanoparticle albumin-bound paclitaxel (nab-paclitaxel) demonstrated greater efficacy with less toxicity than docetaxel in metastatic breast cancer. We conducted a randomized phase II to compare these regimens as neoadjuvant chemotherapy for HER2- early-stage breast cancer.

PATIENTS AND METHODS: Stage I-III human epidermal growth factor receptor-negative (HER2- ) breast cancer patients were included in the present trial and received either docetaxel every 3 weeks or nab-paclitaxel on days 1, 8, and 15 every 28 days for 4 cycles, followed by FEC (5-fluorouracil, epirubicin, cyclophosphamide) every 3 weeks for 4 cycles. The primary endpoint was the pathologic complete response (pCR) rate, defined as ypT0 and ypN0. The secondary endpoints were pCR (ypT0/ypTis and ypN0), the clinical response rate (using the Response Evaluation Criteria In Solid Tumors criteria), histologic effect of treatment (using the Japanese Breast Cancer Society classification), breast conservation rate, and adverse events.

RESULTS: A total of 152 eligible patients were enrolled at 6 centers. The baseline characteristics were well balanced. In comparing the 2 regimens (docetaxel/nab-paclitaxel), the pCR rate was 12% and 17% (P = .323). In the Ki67 > 20% group, the pCR rate was greater (24%) for the nab-paclitaxel arm than for the docetaxel arm (16%; P = .432). The most common grade 3/4 adverse event was neutropenia, observed in 40% and 36% of cases in the nab-paclitaxel and docetaxel arms, respectively. The nonhematologic adverse events of any grade were myalgia (34% and 32%), arthralgia (42% and 35%), and peripheral sensory neuropathy (55% and 65%) for the 2 treatment arms. No grade 3/4 peripheral sensory neuropathy was observed in the nab-paclitaxel arm.

CONCLUSION: Weekly nab-paclitaxel administered at a dose of 100 mg/m2 showed equivalent efficacy and was well tolerated compared with docetaxel as neoadjuvant therapy. Nab-paclitaxel might be more effective in patients with highly proliferative cancer.