Patient-reported outcomes (PROs) during one year of adjuvant enzalutamide for the treatment of early stage androgen receptor positive (AR plus ) triple negative breast cancer

BACKGROUND: A subset of TNBC expresses a luminal signature and demonstrates AR-dependence. Enzalutamide (ENZA), an AR-antagonist, has activity with metastatic AR+ TNBC, with a clinical benefit rate of 33% (Traina et al, JCO 2018). We recently demonstrated that one year (y) of adjuvant ENZA is feasible in early stage, AR+ TNBC, with no new safety signals observed (Traina ASCO 2019). Fatigue was the most common, treatment (tx)-related, adverse event of any grade according to investigator assessment (24%). Here we report per-protocol planned secondary analyses of PROs during one year of ENZA including quality of life (QoL), fatigue, and self-reported physical activity (NCT02750358). METHODS: Eligible patients have Stage I-III, ER/PR RESULTS: Between 5/2016 and 6/2018, 50 patients were enrolled. As of 6/27/19, 34 patients completed 1y of ENZA; 15 patients are off tx: recurrence (3), toxicity (5), nonadherence (4), and consent withdrawal (3). Patients evaluable for PRO (N): baseline (50), 12 weeks (43) and 52 weeks (34). Median scores on FACT-B and fatigue scales remained stable over the course of adjuvant ENZA in the 1st year of therapy (Table). Self-reported exercise increased during this period. CONCLUSIONS: Patient reported outcomes of health related QOL remain stable when ENZA is administered for 1 year in the adjuvant setting. Self-reported time spent engaged in physical exercise increased numerically during 1y of therapy. During presentation, additional analyses will be reported including QOL at additional time points, relationship of FACT-B score with FACIT fatigue score and exercise, and QOL changes in relation to relative dose intensity of ENZA, toxicity and off study reason. Citation Format: Tiffany A Traina, Lee W Jones, Victoria Blinder, Jessica Scott, Leigh Ann Boyle, Artavazd Arumov, Tina Alano, Sujata Patil, Patricia DeFusco, Nicholas Lamparella, Mark Robson, Ayca Gucalp. Patient-reported outcomes (PROs) during one year of adjuvant enzalutamide for the treatment of early stage androgen receptor positive (AR+) triple negative breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-12-09.