Interim analysis of clinical data and reasons for initiating relugolix on a cohort of US patients: The OPTYX study.

e17072 Background: Relugolix is an oral GnRH receptor antagonist indicated for advanced prostate cancer treatment. The OPTYX study is prospectively collecting clinical and patient outcomes data from US patients initiating relugolix in routine care settings to evaluate the long-term outcomes of relugolix therapy. An interim analysis of key baseline variables, reasons for starting relugolix therapy and treatment patterns is presented. Methods: The multi-center observational OPTYX study aims to enroll 1,000 patients with prostate cancer starting relugolix therapy. The current study population includes diverse disease states, treatment circumstances (eg, monotherapy, combination therapy, or intermittent therapy) and clinical settings representative of real-world patterns of care. Baseline demographics, clinical characteristics, reasons for initiating treatment, and treatment patterns from Oct 2022 to Oct 2023 are described. Results: As of October 2023, 394 men were enrolled in the OPTYX study and received relugolix with a median treatment duration of 114 days. The median age was 71 years; 78.7% of patients self-reported as White, 14.2% as Black. Enrollment occurred through Urology, Oncology and Radiation Oncology practices. Most patients (61.2%) had baseline PSA <20 ng/ml. Mean (SD) baseline testosterone was 317.7 (238.5) ng/dL. At baseline, 15.2% of patients had received prior radiotherapy and 20.0% had prior androgen deprivation therapy. Known distant metastases were found in 24.6% of patients. A total of 135 patients (34.3%) received relugolix in combination with other therapies (Table). Top 3 reasons physicians prescribed relugolix were oral instead of injection (40.6%), rapid testosterone suppression (37.6%) and safety (25.1%), while patient reasons were physician recommendation (74.6%), oral instead of injection (35.5%) and safety (8.9%). In 10.7% of patients who discontinued therapy for any reason, 3.3% completed the planned regimen while 3.6% discontinued due to adverse events. No new serious safety signals have been identified. Conclusions: The OPYTX study is evaluating real-world experience with relugolix, including diverse disease states, practice settings and physician specialties. More than a third of patients and physicians favored oral versus injectable formulation, and more than a third used relugolix in combination with other therapies. There was low unplanned discontinuation of relugolix at data cut-off. Clinical trial information: NCT05467176 . Table: see text