Maintenance bevacizumab plus exemestane (E+BEV) for patients with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer who did not progress after treatment with taxane plus bevacizumab (T+BEV) did not achieve longer progression-free survival, according to a study published in Annals of Oncology.1
Researchers led by Olivier Trédan, MD, PhD, of Centre Léon Bérard in Lyon, France, conducted a prospective, open-label, phase 3 study of 117 patients with histologically confirmed ER-positive, HER2-negative metastatic breast cancer and non-progressive disease after 16 to 24 weeks of T+BEV.
Patients were randomized to either continuation of T+BEV or maintenance E+BEV, with primary end point being progression-free survival from randomization.
Interim analysis of 98 patients showed that the probability of reaching a statistically significant improvement in progression-free survival was only 7%, leading the Independent Data and Monitoring Committee to recommend termination of patient enrollment.
After median follow-up of 21 months for all patients, 6-month progression-free survival was 53.6% with T+BEV and 55.2% with E+BEV. Median progression-free survival from BEV initiation was 12.5 months for T+BEV and 12.3 months with E+BEV.
Updated data after a median follow-up of 35 months showed death rates of 44% with T+BEV and 55% with E+BEV.
1. Trédan O, Follana P, Moullet I, et al. A phase III trial of exemestane plus bevacizumab maintenance therapy in patients with metastatic breast cancer after first-line taxane and bevacizumab: a GINECO group study [published online ahead of print February 24, 2016]. Ann Oncol. doi:10.1093/annonc/mdw077.