The addition of the mTOR inhibitor everolimus to first-line exemestane therapy extended PFS compared with exemestane alone in patients with hormone receptor-positive advanced breast cancer, according to study results presented at the Breast Cancer Symposium.
The BOLERO-2 study included patients with HR-positive breast cancer who experienced disease recurrence or progression after treatment with nonsteroidal aromatase inhibitors. Patients received either 10 mg daily everolimus (Afinitor, Zortress; Novartis) plus 25 mg daily exemestane, or everolimus plus placebo.
In a subgroup analysis, Hope S. Rugo, MD, director of the breast oncology clinical trials program at the University of California, San Francisco, and colleagues evaluated outcomes of 137 patients who received either regimen immediately following recurrence during adjuvant therapy.
Hope S. Rugo
Of them, 100 received the combination treatment as first-line therapy in the advanced setting. The other 37 patients received everolimus plus placebo.
PFS served as the primary endpoint.
Among patients in the combination arm, 74% had been treated with adjuvant endocrine therapy plus chemotherapy and 26% had been treated with endocrine therapy alone. Among patients assigned to exemestane alone, 76% had been treated with adjuvant endocrine therapy plus chemotherapy and 24% had been treated with endocrine therapy alone.
Results indicated significantly longer median PFS in the combination arm (11.5 months vs. 4 months; HR=0.39; 95% CI, 0.25-0.62). Researchers observed the trend regardless of whether patients underwent chemotherapy along with prior adjuvant hormonal therapy.
Researchers observed no new safety profiles.
“These results support the combination of everolimus plus exemestane in patients with recurrence after adjuvant therapy,” Rugo and colleagues wrote. “The recently initiated BOLERO-4 study is also evaluating the efficacy of everolimus as a first-line therapy in patients with HR-positive advanced breast cancer.”
Disclosure: The researchers report research funding, honoraria and other remuneration from, consultant/advisory roles and employment/leadership positions with, and stock ownership in Amgen, AstraZeneca, Bayer, Genentech, GlaxoSmithKline, Merck, Novartis, Pfizer, Roche, Sanofi and other pharmaceutical companies.
For more information:
Rugo HS. Abstract #152. Presented at: Breast Cancer Symposium; Sept. 7-9, 2013; San Francisco.