Everolimus in Metastatic Breast Cancer: Clinical Experience as a Late Treatment Line.

Background: Everolimus (Afinitor®) plus exemestane are indicated for hormone receptor-positive, HER2/neu-negative metastatic breast cancer (MBC), in menopausal women without symptomatic visceral disease after recurrence or progression following aromatase inhibitors. But everolimus efficacy as late treatment has not been explored.

Methods: Sixty-three MBC patients progressing under hormonotherapy (HT; n = 30) or after chemotherapy (CT; n = 32) received everolimus plus HT (EHT) and were analyzed for safety, efficacy and overall survival (OS). This cohort was compared with our previous 530 MBC patients stratified by line (PMID 21852136).

Results: The median duration of EHT was 27.8 weeks at 5-10 mg/day until clinical progression or toxicity. Median OS was not reached (median follow-up 18 months). Twelve-month survival was 100, 79 and 49% for patients treated with 0 (n = 13), 1-2 (n = 18) and >3 CT (n = 32), respectively. Median time-to-treatment failure was 6.4 months. In 62 EHT patients randomly matched 1:7 with 421 previous patients for age and number of CT, OS improved compared with patients receiving a new CT (p = 0.062). In patients pretreated with <2 CT, EHT gave a better OS than in those with a new CT (p = 0.026).

Conclusions: These results may support the use of EHT whatever the number of previous lines.