Novel Second-Line Treatment of Aromatase Inhibitor–Resistant Breast Cancer
Posted: Friday, June 8, 2018
The addition of everolimus to fulvestrant seemed to improve progression-free survival in some women with breast cancer that are resistant to aromatase inhibitor therapy. Noah Kornblum, MD, of Montefiore Medical Center, the Bronx, New York, and colleagues reported their findings from the phase II PrE0102 trial in the Journal of Clinical Oncology.
“Everolimus plus anti-estrogen therapy is more efficacious than is anti-estrogen therapy alone in patients with metastatic, hormone receptor–positive, human epidermal growth factor receptor 2–negative breast cancer resistant to [aromatase inhibitor] therapy,” concluded the investigators. “The fulvestrant-everolimus combination represents a new therapeutic option for [aromatase inhibitor]-resistant disease.”
A total of 131 postmenopausal women were enrolled in this multicenter, randomized, double-blind, placebo-controlled trial. The clinical benefit rate favored the combination therapy over antiestrogen therapy alone (63.6% vs. 41.5%), but the objective response rates were similar. The median progression-free survival was 10.3 months in the everolimus group versus 5.1 months in the placebo group (P = .02). The difference in median overall survival between the two arms was not statistically significant (P = .37), although the study was not designed to test this.
Treatment-related adverse events were more common and treatment discontinuation rates were higher with everolimus, compared with antiestrogen therapy alone or placebo. The safety profile with everolimus in this trial was similar to that of everolimus in combination with exemestane or tamoxifen in other trials. The most common adverse event of all grades observed with the everolimus/fulvestrant treatment was oral mucositis.