Abstract P5-12-09: 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

Abstract 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 <1%, HER2(-), AR ≥1% breast cancer and completed all planned standard of care surgery, chemotherapy and radiation within 6 months of study start. Tx = ENZA 160mg orally daily for 1y with the option to extend tx to 2y as per patient preference. Clinician-reported toxicities (NCI CTCAEv4) were assessed every 4 weeks for 12 weeks, then every 3 months. Total study N=50 patients. PROs were assessed every 12 weeks. We examined serial changes in overall QoL (functional assessment of cancer therapy – breast (FACT-B), fatigue (FACIT-fatigue) and exercise behavior (total exercise minutes/week over past 7 days) from pre-treatment and every 3 months thereafter until month 12. All analyses are exploratory and consist of descriptive summaries. 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. Table. Median scores (range) for PROs during 1 year of adjuvant ENZATime PointBaselineWeek 12Week 52FACT-G88.0 (53.5-105.0)82.0 (36.4-105.0)89.5 (58.0-105.0)Breast Cancer Subscale28.5 (15.6-39.0)29.0 (9.0-40.0)29.0 (19.0-40.0)Total118.0 (77.0-141.0)111.0 (45.4-145.0)121.0 (83.0-145.0)FACT-B trial outcome index73.0 (43.0-92.0)73.0 (25.7-96.0)76.9 (51.0-96.0)FACIT43.0 (17.0-52.0)39.0 (10.0-52.0)43.0 (11.0-52.0)Total Exercise (min/week)120 (0-1260)152 (0-3120)180 (0-2580) 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.