A pilot study of adjuvant nanoparticle albumin-bound (nab) paclitaxel and cyclophosphamide,with trastuzumab in HER2-positive patients,in the treatment of early-stage breast cancer

nab-Paclitaxel has shown favorable efficacy and toxicity profiles compared to other taxanes in the treatment of metastatic breast cancer. In this pilot trial, we evaluated a nab-paclitaxel-containing adjuvant regimen in patients with early stage breast cancer. Patients with node-positive or high-risk node-negative early-stage breast cancer were eligible following completion of standard primary therapy. All the patients received four cycles, at 21-day intervals, of nab-paclitaxel (100 mg/m² IV days 1, 8, and 15) and cyclophosphamide (600 mg/m² IV day 1). HER2-positive patients also received trastuzumab 8 mg/kg IV on cycle 1 day 1, followed by 6 mg/kg every 21 days for a total of 52 weeks. The purpose of this trial was to evaluate feasibility and toxicity of this nab-paclitaxel-containing adjuvant regimen. 62 patients were treated between 2/08 and 11/08. The majority of the patients (87%) were HER2-negative. This adjuvant regimen was well tolerated, and full doses of all agents were administered in >90% of cycles. Grade 3/4 neutropenia occurred in 53% of the patients; however, only one episode of febrile neutropenia occurred in a total of 249 cycles administered. Other grade 3/4 adverse events occurred in less than 5% of patients. After short follow-up, all the patients remain alive and disease-free. The combination of nab-paclitaxel and cyclophosphamide, with or without trastuzumab, is feasible and well tolerated in patients with early stage breast cancer. Further investigation of the role of nab-paclitaxel in adjuvant breast cancer therapy is indicated, but definitive evaluation will require randomized phase III trials.