Safety of everolimus for women over 65 years of age with advanced breast cancer (BC): 12.5-mo follow-up of BOLERO-2.

Abstract

551 Background: Postmenopausal women with estrogen-receptor–positive (ER+) BC who relapse/progress on a nonsteroidal aromatase inhibitor (NSAI) are usually treated with the steroidal AI exemestane (EXE); but there is no currently approved treatment for this indication. The BOLERO-2 trial showed that adding everolimus (EVE), an oral inhibitor of mammalian target of rapamycin (mTOR), to EXE significantly improved clinical benefit beyond that of EXE alone (Hortobagyi et al, SABCS 2011, Abstract S3-7). As many women with advanced BC are elderly, the tolerability profile of EVE + EXE in this population is of interest. Methods: BOLERO-2 is a phase III, randomized, trial comparing EVE (10 mg once daily) vs placebo (PBO), both plus EXE (25 mg once daily) in postmenopausal women with advanced ER+ BC progressing or recurring after NSAIs. Safety data with a focus on elderly patients are reported at 12.5 mo median follow-up. Results: Baseline disease characteristics, age, and prior cancer therapy were well balanced between treatment arms (N = 724). At 12.5 months’ median follow-up, the addition of EVE to EXE significantly improved progression-free survival in patients <65 (HR = 0.37; P < .05) or ≥65 years of age (HR = 0.56; P < .05). Adverse events (AEs) of special interest (all grades) occurring more frequently with EVE vs PBO (overall study population) included stomatitis (66.6% vs 11.3%), infections (50.4% vs 25.2%), rash (44.0% vs 8.4%), pneumonitis (18.7% vs 0.4%), and hyperglycemia (15.4% vs 2.5%). Elderly EVE-treated patients (≥65 years) had similar or marginally lower incidence of stomatitis (52.1%), rash (32.3%), pneumonitis (14.6%), and hyperglycemia (12.5%) compared with the overall population. Grade 3/4 AEs in patients ≥70 years of age (n = 161) reported only among patients receiving EVE (n = 118) included fatigue (10.2%), anemia (10.2%), hyperglycemia (8.5%), stomatitis (7.6%), dyspnea (6.8%), pneumonitis (5.1%), neutropenia (3.4%), and hypertension (3.4%). Conclusions: Adding EVE to EXE was well tolerated in the overall population and in elderly patients with advanced BC; grade 3/4 AEs were uncommon and manageable. Overall, AEs were consistent with the known safety profile of EVE.