Characterization of patients who received prior chemotherapy for advanced breast cancer (ABC) in BOLERO-2.

151 Background: In patients with hormone receptor–positive (HR+) breast cancer, endocrine therapy is the standard of care both in the adjuvant setting and as front-line therapy for ABC. Chemotherapy (CT) is commonly used for HR+ ABC patients if disease burden is high and rapid symptom control is required (Barrios CH. GAMO. 2010). In the phase III BOLERO-2 study (NCT00863655), first-line of prior CT in the ABC setting was allowed. This subset analysis examined disease characteristics and the efficacy of everolimus (EVE) + exemestane (EXE) in patients who received CT for ABC prior to BOLERO-2 study entry. Methods: In BOLERO-2, 724 patients with HR+, human epidermal growth factor receptor 2–negative (HER2–) ABC whose disease recurred or progressed during/after a nonsteroidal aromatase inhibitor were randomized 2:1 to EVE (10 mg/d) + EXE (25 mg/d) or placebo (PBO) + EXE. The primary endpoint was progression-free survival (PFS) by local investigator review (confirmed by blinded independent central review). Res...