The adoption of relugolix for treatment of prostate cancer (PCa) in a large community medical oncology practice

ABSTRACT

Background: Relugolix was approved by the FDA in late 2020 as an oral gonadotropin-releasing hormone (GnRH) receptor antagonist for the treatment of adults with advanced PCa. The approval was based on a large randomized trial (Shore et al NEJM) of patients with evidence of biochemical or clinical relapse after local primary intervention with curative intent (50%), newly diagnosed mCSPCa (23%), and advanced localized disease not suitable for primary surgical intervention with curative intent (28%). Our study aims to observe the adoption of relugolix in a large community-based medical oncology practice with affiliated urologists. Methods: A retrospective study using our EMR identified 39 males with PCa for whom relugolix was initiated between January 2021 and December 2021. The charts were analyzed for demographics, indications for treatment, barriers encountered to initiation of treatment, duration of therapy, previous therapies, specialty, primary insurance, and cardiovascular history. Results: Thirty-nine (39) patients with either localized PCa (40%) or with metastases to lymph nodes or distant sites (51%) were recommended initiation of relugolix by either urology (26%) or oncology (74%). Of these, 77% actually started the medication. 9 patients did not start therapy, of which 3 were due to insurance denial, 1 due to death, 2 changed their mind, and 3 did not start for unclear reasons. Medicare covered 56% of the patients. Cardiovascular disease was notable in 87%. 28% switched from another ADT due to intolerance, 10% started relugolix due to progressive disease, and 33% started as initial ADT. 13% discontinued within 6 months. Of these, 1 completed planned therapy, 3 were intolerant, 1 was switched to alternate therapy due to progression, and 1 had complications due to COVID. In comparison, 689 patients initiated ADT with leuprolide over the same time. Conclusions: ADT using GnRH agonists or antagonists form the backbone of PCa treatment, typically given as injections. The HERO trial showed that relugolix, a newer oral therapy, is associated with lower rates of cardiovascular events compared to leuprolide. While having at least one cardiovascular risk factor is a consideration for patients to either start with or switch to relugolix, the large majority of our patients still received first-line therapy with leuprolide. This study demonstrates limitations to initiating relugolix including financial constraints (e.g., insurance coverage), patient preference, and medication intolerance. (Table Presented).