A Randomized Phase II Study of Fulvestrant in Combination With the Dual mTOR Inhibitor AZD2014 or Everolimus or Fulvestrant Alone in Estrogen Receptor-positive Advanced or Metastatic Breast Cancer

This is an open-label, multicentre, 4-arm randomised phase II trial of fulvestrant + AZD2014 versus fulvestrant + everolimus versus fulvestrant alone in patients with ER-positive, HER2-negative advanced or metastatic breast cancer, whose disease relapsed during treatment with (or within 12 months after discontinuation of) an AI in the adjuvant setting or progressed during treatment with an AI in the metastatic setting. Patients will be randomised (2:3:3:2) to one of the four treatment arms:

• Fulvestrant
• Fulvestrant + AZD2014 (continuous daily schedule)
• Fulvestrant + AZD2014 (intermittent schedule - 2 days on, 5 days off)
• Fulvestrant + everolimus

Randomization will be stratified by the following criteria:

• Measurable disease (vs. non-measurable).
• Sensitivity to prior endocrine therapy (sensitive versus resistant) Sensitivity to prior endocrine therapy is defined as (i) at least 24 months of endocrine therapy before recurrence in the adjuvant setting or (ii) a complete or partial response to prior metastatic endocrine treatment, or (iii) stabilization for at least 24 weeks of endocrine therapy for advanced disease.

Treatment will be continued until disease progression unless there is evidence of unacceptable toxicity or if the patient requests to be withdrawn from the study. If one of the treatments (fulvestrant or mTOR inhibitor) is discontinued prior to disease progression, patients should be continued on single agent treatment until progression, evidence of unacceptable toxicity or if the patient requests to be withdrawn from the study.