Long-Term Weekly Paclitaxel vs. Nab-paclitaxel or Ixabepilone as First-Line Therapy for Metastatic Breast Cancer
By: Meg Barbor, MPH
Posted: Thursday, January 11, 2018
In patients with chemotherapy-naive metastatic breast cancer, treatment with paclitaxel was better tolerated and resulted in longer progression-free survival than either nab-paclitaxel or ixabepilone, according to the long-term follow-up of the phase III CALGB 40502/NCCTG N063H (Alliance) trial. These findings were presented by Hope S. Rugo, MD, Director of the Breast Oncology Clinical Trials Program, University of California, San Francisco, and colleagues, at the 2017 San Antonio Breast Cancer Symposium (SABCS; Abstract GS3-06).
The trial randomized 799 patients to receive weekly nab-paclitaxel (n=271), ixabepilone (n=245), or paclitaxel (n=283) between November 2008 and November 2011. A total of 98% of patients also received bevacizumab. Ixabepilone was inferior to paclitaxel, and nab-paclitaxel was not superior, with a trend toward inferiority, according to previously reported data.
After a median follow-up of 5 years, median progression-free survival is unchanged at 10.8, 9.2, and 7.4 months for paclitaxel, nab-paclitaxel, and ixabepilone, respectively, the investigators reported.
In an unplanned retrospective subset analysis of the 68% of patients with hormone receptor–positive (HR+) and 25% of patients with triple-negative breast cancer, ixabepilone and nab-paclitaxel were inferior to paclitaxel in hormone receptor–positive disease, with a suggestion of improved progression-free and overall survival with nab-paclitaxel in patients with triple-negative disease. According to the researchers, further investigation is required to validate the subtype specificity seen in this analysis.