High pathologic complete response in Her2-positive, early-stage breast cancer to a novel nonanthracycline neoadjuvant chemotherapy.

Neoadjuvant chemotherapy is widely used to downstage breast cancers before surgery and is an accepted standard of care among patients with early-stage breast cancer in whom adjuvant chemotherapy would be recommended. Pathologic complete response (pCR) rate is a robust predictor of outcome for certain breast cancer subtypes, including Her2-overexpressing breast cancer. The incorporation of Her2-targeted therapies has significantly increased the pCR rate in the neoadjuvant setting. Although regimens composed of trastuzumab, nab-paclitaxel, and vinorelbine have demonstrated clinical efficacy in patients with metastatic breast cancer, few studies have examined this combination in early-stage Her2+ breast cancer. We hypothesized that the combination of neoadjuvant nab-paclitaxel followed by vinorelbine could represent a nonanthracycline-based treatment option for early-stage Her2-overexpressing breast cancer.Patients received 4 cycles of nab-paclitaxel 260 mg/m(2) intravenously (IV) every 14 days for 4 cycles followed by vinorelbine 25 mg/m(2) IV weekly for 12 weeks with concurrent trastuzumab (4 mg/kg loading dose, and then 2 mg/kg/wk). The primary endpoint was the rate of pCR. Secondary endpoints included clinical response, toxicity, and survival rates.A total of 27 patients were accrued to the trial. The median tumor size was 4.0 cm, and more than 50% of patients had axillary lymph node involvement. The pCR rate was 48.1%. Among the 40% of patients who had hormone receptor-positive disease, the pCR rate was 18.2%, compared with 68.8% among patients with estrogen receptor/progesterone receptor-negative tumors.The combination of trastuzumab with nab-paclitaxel followed by vinorelbine was well tolerated and had promising activity in the neoadjuvant setting.