Quality of life, adherence, and adverse events among patients with advanced prostate cancer treated with relugolix: 6-month results of the OPTYX multicenter registry.

122 Background: Relugolix is the only oral androgen deprivation therapy FDA approved for advanced prostate cancer (PC), based on the phase 3 randomized HERO trial. Data on quality of life (QoL), adherence, and safety in real-world clinical practice are needed. Methods: OPTYX is a prospective multicenter observational study (NCT05467176) of US patients with PC initiating treatment with relugolix ≤1 month before enrollment; androgen receptor pathway inhibitors could be added or withdrawn at physician’s discretion. Patients with an intended treatment plan of <4 months of relugolix were excluded. We report 6-month data on QoL (Functional Assessment of Cancer Therapy – Prostate [FACT-P]), adherence (Simplified Medication Adherence Questionnaire [SMAQ]), and adverse events (AEs). Results: As of March 7, 2025, 999 patients were enrolled in OPTYX median age was 71 years. A total of 364, 772, and 628 patients had FACT-P data assessed at baseline, 3 months, and 6 months, respectively. FACT-P total mean (SD) score was 120.0 (20.3) at baseline, and was maintained at 3 and 6 months (119.1 [20.5] and 120.2 [20.0], respectively). FACT-P subscale scores were also stable over 6 months (Table). Using the SMAQ, the percentage of patients taking relugolix at the appropriate time of day was 95.8%, and the percentage of patients who reported discontinuing relugolix when feeling bad was 4.0% at 6 months (n=618). At 6 months, 83.1% (513/617) reported never forgetting to take relugolix. Of 16.9% who reported forgetting to take relugolix at least once, a mean of 1.3 days of missed relugolix occurred over the past 3 months. Serious AEs were uncommon and occurred in 39 (3.9%) patients; the most common (>2 patients) were anemia (0.4%) and acute myocardial infarction (0.3%). AEs led to treatment discontinuation in 6.2% of patients; 2 deaths were reported (0.2%). Conclusions: Real-world utilization of relugolix was associated with stable QoL, high treatment adherence, and a low rate of serious AEs over the first 6 months. Patients will continue to be followed for a longer-term analysis in this ongoing study. Clinical trial information: NCT05467176 . Assessment Baseline 3 mo 6 mo FACT-P total score Mean (SD) 120.0 (20.34) 119.1 (20.54) 120.2 (19.95) Median (range) 122.8 (39-156) 112.9 (44-154) 124.0 (41-156) FACT-P physical well-being Mean (SD) 24.4 (3.99) 22.8 (4.57) 22.9 (4.25) Median (range) 26.0 (7-28) 24.0 (3-28) 24.0 (3-28) FACT-P social/family well-being Mean (SD) 22.7 (4.88) 22.3 (5.03) 22.6 (4.68) Median (range) 24.0 (4-28) 24.0 (0-28) 24.0 (0-28) FACT-P emotional well-being Mean (SD) 18.8 (4.03) 20.1 (3.70) 20.2 (3.77) Median (range) 20.0 (0-24) 21.0 (4-24) 21.0 (0-24) FACT-P functional well-being Mean (SD) 20.8 (6.19) 20.7 (5.84) 20.9 (5.72) Median (range) 22.0 (4-28) 22.0 (2-28) 22.0 (0-28) FACT-P prostate cancer subscale Mean (SD) 33.3 (7.84) 33.2 (7.48) 33.5 (7.28) Median (range) 34.0 (3-48)</ja