The present multi-center, open-label, single-arm study aims to evaluate the efficacy and safety, quality of life and health resources utilization in postmenopausal women with hormone receptor positive breast cancer progressing following prior therapy with non-steroidal aromatase inhibitors (NSAI) treated with the combination of Everolimus and Exemestane.

In light of the need for new treatment options for postmenopausal, hormone receptor positive, HER2 negative women after failure of prior non-steroidal aromatase inhibitor (NSAI) therapy, the BOLERO-2 trial was performed and demonstrated significant efficacy of the combinatorial treatment of Everolimus and Exemestane compared to an Exemestane monotherapy in this setting.

In this randomized, double blind, placebo-controlled trial a statistically significant improvement in progression-free survival (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 quality of life data shows positive trend in the Everolimus plus Exemestane treatment arm. (Baselga 2011, Hortobagyi 2011). Thus, the benefit of the combinatorial treatment versus Exemestane monotherapy was shown in a defined patient population under controlled conditions.

The primary objective of this trial to assess the Overall Response Rate (ORR) in postmenopausal women with hormone receptor positive breast cancer progressing following prior therapy with NSAIs treated with the combination of Everolimus and Exemestane. The secondary objectives include, Progression free survival (PFS), Overall survival (OS), Safety, Change in Quality of life scores over time, Health resource utilization. The exploratory objectives reflect scientific interest within the treatment of metastatic breast cancer and are to be modified, if applicable, according to the current scientific state of the art at the time of actual analysis. These include: the influence of age, performance status, cancer activity and inflammation on anxiety and depression; changes in serum bone-turnover biomarkers; Pharmacogenetics of Everolimus in patients with advanced breast cancer; presence and molecular characteristics of Circulating Tumor Cells; correlation of response to Exemestane/Everolimus with Proteomic analysis.

The present national, multi-center, open-label, single-arm study aims to evaluate the efficacy and safety, quality of life and health resources utilization of the combination of Everolimus and Exemestane in a broader patient population compared to BOLERO-2, i.e. without limitations as to the number of previous chemotherapy lines, the time point of progression after NSAI therapy, and the previous endocrine therapy as patients under Exemestane monotherapy may be enrolled. Since the combination was shown to significantly improve PFS in the previous BOLERO-2 trial, for ethical reasons no endocrine comparator drugs will be investigated in the present study, due to the low efficacy of Exemestane monotherapy (PFS 3.2 months).

Main Inclusion criteria:

Metastatic or locally advanced breast cancer not amenable to curative treatment by surgery or radiotherapy or any other non-systemic treatment.

Histological or cytological confirmation of estrogen receptor positive (ER+) and/or progesterone receptor positive (PgR+), human epidermal growth factor receptor 2 (HER2) negative breast cancer Postmenopausal women. Disease progression following prior therapy with non steroidal aromatase inhibitors (NSAI), defined as: Recurrence while on, or following completion of an adjuvant treatment with Letrozole or Anastrozole, or Progression while on or following completion of Letrozole or Anastrozole treatment for ABC/MBC.

Radiological evidence of recurrence or progression on last systemic therapy prior to enrollment.

Patients must have at least one lesion that can be accurately measured or bone lesions: lytic or mixed (lytic + sclerotic) in the absence of measurable disease.

Written informed consent obtained before any screening procedure and according to local guidelines.

Other protocol defined inclusion criteria apply.

Main Exclusion criteria:

HER2-overexpressing patients by local laboratory testing (IHC 3+ staining or in situ hybridization positive).

Patients with only non-measurable lesions other than bone metastasis (e.g. pleural effusion, ascites etc.).

Previous treatment with mTOR inhibitors or known hypersensitivity to mTOR inhibitors.

Symptomatic brain or other CNS metastases. Previously treated brain metastases are allowed provided the patient is free of symptoms, prior radiotherapy for brain metastasis was more than four weeks before enrollment and the dose of corticosteroids is low (i.e. ≤ 10 mg/d Prednisolone equivalent) and stable for at least two weeks prior to enrollment.

Patients with Hepatitis B or C or with a history of Hepatitis B or C. Patients unwilling to or unable to comply with the protocol. Other protocol defined exclusion criteria apply.