Everolimus + Exemestane Improves PFS in Some HR+ Breast Cancer
(CHICAGO, IL) – Adding everolimus (Afinitor) to the oral steroidal aromatase inhibitor exemestane (Aromasin) improved progression-free survival (PFS) in postmenopausal women with hormone receptor-positive (HR+) advanced breast cancer, according to the results of the phase 3 BOLERO-2 trial reported at the 2012 American Society of Clinical Oncology Annual Meeting.
“The addition of everolimus to exemestane can provide an effective new option for patients with advanced breast cancer, especially in elderly patients who may not tolerate toxic treatments,” reported lead author Kathleen I. Pritchard, MD, Professor of Medicine at the Sunnybrook Odette Cancer Centre, University of Toronto, Ontario, Canada. The combination was, “well tolerated in the overall population and in elderly patients with advanced breast cancer; grade 3/4 adverse events were uncommon and manageable,” she added.
This report presented median 18-month follow-up safety and efficacy data from the elderly subset of patients with breast cancer who had progressed or recurred after nonsteroidal aromatase inhibitors enrolled in BOLERO-2 (Breast cancer trials of OraL EveROlimus-2) trial. Patients were randomly allocated in a 2:1 ratio to receive everolimus 10mg/day or matching placebo; all patients received open-label exemestane 25mg/day.
Of 724 patients enrolled in the trial, 275 were ≥65 years of age and 164 were ≥70 years of age. Disease and pretreatment characteristics in the elderly subset, defined as 65 years of age and older, were comparable to that of younger patients.
The trial showed that adding everolimus to exemestane significantly improved clinical benefit over exemestane alone. The combination reduced the risk of PFS events by 41% in the ≥65-year group and by 55% in the ≥70-year group. “The PFS benefit in elderly patients was comparable to that of younger patients, regardless of the age cut-off,” Dr. Pritchard added. In patients <65 years of age, median PFS was 8.31 months in the everolimus plus exemestane group vs. 2.92 months for the placebo arm (HR = 0.38; P<0.05); in those 65 years or older, median PFS was 6.83 vs. 4.01 months, respectively (HR = 0.59; P<0.05).
The best overall response in patients ≥65 years and ≥70 years of age in the combination arm was 2 complete responses in each group.
In general, the safety profiles were similar between the older and the younger patients. The most common adverse events in those older than 65 years of age were stomatitis (~50%), fatigue (~37%), decreased appetite (~35%) and diarrhea (~35%).Adverse events of special interest observed at similar frequencies in the older and younger patients were pneumonitis (~15% in older vs 17% in younger patients); hyperglycemia (~13% vs 15%), and hypercholesterolemia (~7% vs 15%).
Dr. Pritchard added that these adverse events were consistent with the known safety profile of everolimus.