Bicalutamide Plus Aromatase Inhibitors in ER(+)/AR(+)/HER2(-) Metastatic Breast Cancer

A Phase II Study of the Efficacy and Tolerability of Bicalutamide Plus Aromatase Inhibitors in Estrogen Receptor(+)/Androgen Receptor(+)/HER2(-) Metastatic Breast Cancer

This study is aim to evaluate the efficacy and safety of bicalutamide and aromatase inhibitor in ER(+)/AR(+)/HER2(-) metastatic breast cancer patients who have disease progression after treatment of an aromatase inhibitor.

Androgen receptor(AR) is closely related to molecular type, treatment and prognosis in breast cancer. Over 70% of breast cancer expressed androgen receptor. And in some estrogen receptor positive breast cancer cells which are resistant to Aromatase inhibitors can change androgen receptor dependent. So AR may be a new target in the treatment of breast cancer. Bicalutamide is a selective androgen receptor inhibitor with a clinical benefit rate of 19% and median progression free survival of 12 weeks in the ER-/AR+ metastatic breast cancer. This study is aim to evaluate the efficacy and safety of bicalutamide and aromatase inhibitor in ER+/AR+/HER- metastatic breast cancer patients who have disease progression after treatment of an AI.

Inclusion Criteria:

• Patients with histologically confirmed estrogen receptor positive, androgen positive and HER2 negative breast cancer
• Metastatic or unresectable locally advanced disease
• Age over 18 years
• Postmenopausal status （continuous using luteinizing hormone releasing hormone(LHRH) analogue is available）
• Patient must have disease progression after treatment of an Aromatase inhibitor.
• Eastern Cooperative Oncology Group (ECOG) performance status (PS)0-2
• Life expectancy over 3 months.
• Measurable disease according to RECIST version 1.1 or only bone metastasis
• Adequate hematological, hepatic function.
• Voluntarily signed and dated written informed consent prior to any study specific procedure.

Exclusion Criteria:

• Patient with life-threatening visceral metastasis, such as extensive liver metastasis, brain or meningeal metastasis
• Concomitant diseases/conditions that is not controllable, and Any other major illness that, in the Investigator's judgment, will substantially increase the risk associated with the patient's participation in this study.
• History of other primary malignancy
• Resistant to steroidal or nonsteroidal aromatase Inhibitor