311TiP - FRIEND: A randomized pilot study to compare the efficacy and tolerability of fulvestrant 500mg with exemestane as first line endocrine therapy for post-M ER positive HER2 negative ABC patients relapse after adjuvant non-steroidal aromatase inhibitors (NSAI)

Abstract

Background: Breast cancer is one of the most common malignancies in women. It has long been acknowledged that oestrogen acts as an endocrine growth factor for hormone-dependent breast cancer. Fulvestrant is a selective estrogen receptor degrader – an ER antagonist with a novel mode of action. Confirm & China Confirm study demonstrated that the efficacy of Fulvestrant 500mg is superior to 250mg. FIRST&FALCON study results confirmed the superior efficacy of fulvestrant over anastrozole in postmenopausal women who have not received prior hormonal therapy. But in the clinical practice, AI are widely used as adjuvant ET for postmenopausal ER+ breast cancer patients. To date there are no randomized trials to compare Fulvestrant 500mg with AI in patients who have relapsed during or after adjuvant non-steroidal AI. Trial design: The FRIEND trial is a parallel-group, multi-centre study designed to compare the efficacy and tolerability of fulvestrant 500 mg with exemestane 25 mg as first line endocrine therapy in post-M women with ER positive HER2 negative ABC who have relapsed on or after at least 2 years of adjuvant NSAI therapy. Approximately 148 postmenopausal women with ER positive HER2 negative advanced breast cancer who have relapsed whilst on adjuvant NSAI (treatment duration ≥2 years) or after completed adjuvant NSAI treatment will enter this study. Eligible patients will be randomized 1:1 to the following treatment groups: Fulvestrant 500 mg i.m. every 28 (± 3) days plus an additional 500 mg on day 15 (± 3) of first month only; Exemestane 25 mg, orally, once daily. Treatment will continue until disease progression or treatment discontinuation. The primary endpoint is progression-free survival. Secondary endpoints include objective response rate, disease control rate, time to treatment failure, duration of response and overall survival. Efficacy will be determined based on tumor assessments performed by each investigator according to RECIST version 1.1. Safety will be monitored based on the frequency and severity of adverse events (AEs). This study is currently recruiting patients. Clinical trial identification: NCT02646735 Legal entity responsible for the study: NA Funding: AstraZeneca China Disclosure: All authors have declared no conflicts of interest.