Dr McKay on the Background of the Phase 4 OPTYX Trial in Advanced Prostate Cancer

“[Relugolix] is the only oral approved GnRH analog. In the phase 3 HERO trial, relugolix was associated with more rapid and sustained testosterone suppression and was generally safe and well tolerated. It was also associated with more rapid testosterone recovery upon discontinuation and potentially improved cardiovascular outcomes. To supplement those clinical trial data, relugolix is being investigated in the phase 4 OPTYX trial.”

Rana R. McKay, MD, a professor in the Department of Medicine and the Department of Urology at UC San Diego School of Medicine, discussed the rationale for the initiation of the phase 4 OPTYX trial (NCT05467176) evaluating the real-world use of relugolix (Orgovyx) in patients with advanced prostate cancer.

OPTYX was a prospective, multicenter, observational study that enrolled adult patients with prostate cancer in the United States who received relugolix as monotherapy or as a combination component. Patients needed to have received relugolix at the time of study enrollment or within 1 month prior to enrollment while remaining on treatment at the time of enrollment and be willing to complete patient-reported outcome assessments. Patients who had an intended treatment plan with relugolix of less than 4 months were excluded.

McKay noted that androgen deprivation therapy (ADT) is a key treatment in the management of prostate cancer. Oftentimes, ADT is used in combination with other therapies, including next-generation hormonal agents, she added.

The oral ADT relugolix is the only FDA-approved gonadotropin-releasing hormone receptor antagonist, McKay explained. Findings from the phase 3 HERO trial (NCT03085095) showed that the agent was associated with more rapid and sustained testosterone suppression and was generally safe and well tolerated, she said. It was also associated with more rapid testosterone recovery upon discontinuation and improved cardiovascular outcomes, she added. In order supplement these data with real-world findings, investigators initiated the OPTYX study.

In OPTYX, patients were assessed for quality of life via Functional Assessment of Cancer Therapy–Prostate Criteria (FACT-P) criteria; treatment adherence using the Simplified Medication Adherence Questionnaire; and safety per incidence of serious adverse effects, treatment discontinuation, and death. The FACT-P was completed at baseline as well as at 3 and 6 months. Findings from OPTYX were presented in a poster during the 2026 Genitourinary Cancers Symposium.

Disclosures: McKay holds consulting or advisory roles with Ambrx, Arcus Biosciences, Astellas Medivation, AstraZeneca, AVEO, Bayer, Blue Earth Diagnostics, Bristol Myers Squibb, Calithera Biosciences, Caris Life Sciences, Daiichi Sankyo, Dendreon, Esiai, Exelixis, Janssen, Lilly, Merck, Myovant Sciences, NeoMorph, Novartis, Pfizer, Precede Bio, Sanofi, Seagen, Sorrento Therapeutics, Sumitomo Pharma Oncology, Telix Pharmaceuticals, Tempus, and Vividion Therapeutics. She also received research funding from Artera (Inst), AstraZeneca (Inst), Bayer (Inst), Bristol Myers Squibb (Inst), Exelixis (Inst), Oncternal Therapeutics (Inst), and Tempus (Inst).