Patient-reported health-related quality of life (HRQoL) in the randomized FORMULA-509 trial of salvage radiotherapy and 6 months of GnRH agonist with either bicalutamide or abiraterone acetate plus prednisone (AAP) and apalutamide (Apa) after radical prostatectomy (RP).

Abstract

260 Background: The randomized FORMULA-509 trial demonstrated that for patients with a PSA >0.5 after RP receiving salvage radiation and 6 months of GnRH Agonist, the addition of AAP and Apa improved metastasis-free survival compared to bicalutamide. Here we present the patient-reported health-related quality of life (HRQoL) results. Methods: Validated questionnaires were administered at baseline, end of treatment, and 1 year after completion of treatment. Patients completed EPIC-26, PROMIS Fatigue, and Saint Louis University Mental Status Exam (SLUMS). EPIC-26 is scored from 0 to 100 with 100 indicating higher function. PROMIS Fatigue is scored using a standardized T score with higher score indicating greater fatigue. SLUMS is scored from 0 to 30 with 27 to 30 interpreted as normal, 21 to 26 as mild neurocognitive disorder and 20 or less as dementia. Scores between treatment arms were compared using the t-test. Results were interpreted using established thresholds for clinically meaningful differences (4-6 for EPIC-26 hormonal domain, 5-10 for PROMIS Fatigue). Results: 345 patients were randomized (172 bicalutamide; 173 AAP/Apa). Completion rates at baseline, end of treatment, and 1 year, were 96%, 80%, and 70% for EPIC-26, 95%, 79%, and 67% for PROMIS Fatigue, and 96%, 80%, and 70% for SLUMS. From baseline to end of treatment, both arms demonstrated clinically meaningful declines in EPIC-26 hormonal domain (median change -15 bicalutamide; -15 AAP/Apa) and increase in PROMIS Fatigue (median change 6 bicalutamide; 7.4 AAP/Apa). From end of treatment to 1 year after treatment patient-reported HRQoL improved to near baseline for both EPIC-26 hormonal function (bicalutamide median score baseline: 95, end: 75, 1 year: 90; AAP/Apa baseline: 95, end: 75, 1 year: 90) and fatigue (bicalutamide median score baseline: 43.1, end: 48.6, 1 year: 46.0; AAP/Apa baseline: 43.1, end: 51.0, 1 year: 46.0). Median SLUMS score was within normal range at baseline (27 bicalutamide; 27 AAP/Apa), end of treatment (28, 28) and 1 year after treatment (27, 27). There was no difference in patient-reported hormonal function, fatigue, or mental status between treatment arms, at end of treatment (p=0.40; 0.78; 0.41 respectively) and 1 year after treatment (p=0.78; 0.89; 0.76 respectively). Conclusions: The addition of AAP/Apa improved oncologic outcomes without causing a detectable difference in patient-reported hormonal function, fatigue, or mental status compared to bicalutamide. Clinical trial information: NCT03141671 .