Fulvestrant and EVerolimus Plus EXemestane in Metastatic Breast Cancer

In this study everolimus will be administered in combination with exemestane, which is an irreversible steroidal aromatase inactivator that has demonstrated efficacy in the treatment of postmenopausal patients with ABC. Exemestane is indicated for adjuvant treatment of postmenopausal women with HR+ EBC who have received two to three years of tamoxifen and are switched to exemestane for completion of a total of five consecutive years of adjuvant hormonal therapy. It is also indicated for the treatment of ABC in postmenopausal women whose disease has progressed following tamoxifen therapy (in the USA) or following antiestrogen therapy (in Europe). In 2011, the BOLERO-2 trial reported (5; 33) a significant benefit for HR+ HER2- postmenopausal pretreated women in the ABC setting by combining everolimus with exemestane. In this randomized, double-blind, placebo-controlled trial a statistically significant improvement in PFS by adding everolimus to exemestane versus exemestane alone was reported. Adding everolimus determined a 2.4-fold prolongation in PFS from 3.2 up to 7.4 months and so lowered the risk of cancer progression by 56% for these women. These findings were confirmed by an independent assessment (4.1 vs. 11.0 months, risk reduction: 64%). The QoL data shows positive trend in the everolimus plus exemestane treatment arm.