Three-Week Versus 4-Week Schedule of nab-Paclitaxel in Patients With Metastatic Breast Cancer: A Randomized Phase II Study.

Background: This head-to-head study compared a 3-week versus 4-week schedule of nab-paclitaxel in patients with metastatic breast cancer (mBC). Methods: Patients with HER2-negative mBC were enrolled and randomly assigned (1:1) to receive nab-paclitaxel for a 3-week schedule (125 mg/m² on days 1 and 8) or a 4-week schedule (same dose on days 1, 8, and 15) until disease progression or treatment intolerance. Patients with intolerable toxicities were allowed to receive a maintenance regimen after benefiting from nab-paclitaxel. The primary endpoint was progression-free survival (PFS). Results: Ninety-four patients were included in the analysis (n = 47 in each arm). A longer median PFS (mPFS) was observed in the 3-week versus the 4-week schedule in the overall population (not reached vs. 6.8 months; hazard ratio [HR] = 0.44; P = .029). Patients in the 2 arms had a similar overall survival (28.0 vs. 25.8 months), objective response rate (51.1% vs. 48.9%), and disease control rate (93.6% vs. 80.9%). The 3-week schedule was associated with a lower rate of toxicity-related treatment discontinuation (8.5% vs. 29.8%) and dose delays (6.4% vs. 23.4%). Conclusion: This study demonstrated the better antitumor activity and safety profile of a 3-week over 4-week nab-paclitaxel schedule in HER2-negative mBC, suggesting that a 3-week schedule may be a better treatment regimen in clinical practice (ClinicalTrials.gov Identifier: NCT04192331). This study compared a 3-week versus 4-week schedule of nab -paclitaxel in patients with metastatic breast cancer. [ABSTRACT FROM AUTHOR]