Phase I Study of Combination Therapy With Weekly Nanoparticle Albumin-bound Paclitaxel and Cyclophosphamide in Metastatic Breast Cancer Patients

BACKGROUND/AIM: The objective of this phase I study was to determine the maximum-tolerated dose (MTD) and recommended dose (RD) of combination therapy with weekly nanoparticle albumin-bound paclitaxel (nab-paclitaxel) and cyclophosphamide (CPA) in metastatic breast cancer (MBC) patients. PATIENTS AND METHODS: Five patients who had human epidermal growth factor receptor 2 (HER2) negative MBC were recruited in this study. They received nab-paclitaxel at dose levels of 100-150 mg once a week for three weeks, repeated every 4 weeks, and CPA (600 mg/m(2)) administered on day 1. RESULTS: No patient had grade 4 toxicity, however, two patients discontinued protocol treatment due to adverse events at level 2. Thus, the Data and Safety Monitoring Committee recommended the MTD of nab-paclitaxel and CPA to be determined at level 2. CONCLUSION: The combination therapy with weekly nab-paclitaxel and CPA was tolerable, and the RD for these drugs for MBC were 100 and 600 mg/m(2), respectively.