Real-World VHA Data Show High Relugolix Adherence Across Races in Prostate Cancer
Key Clinical Summary
- Veterans Health Administration (VHA) data show >90% adherence to oral relugolix during the first year of therapy, with no significant racial differences.
- PSA response rates among ADT-naïve patients were high and comparable between Black and White veterans.
- Black patients were more likely to discontinue or switch therapy, though reasons remain unclear and require additional study.
New real-world evidence from the Veterans Health Administration—the largest integrated health care system in the US—provides insight into adherence and prostate-specific antigen (PSA) response patterns with relugolix, the only US Food and Drug Administration (FDA)-approved oral androgen deprivation therapy (ADT). The study, covering veterans initiating therapy from December 2020 to December 2023, assessed treatment patterns and racial differences in outcomes among Black and White patients with prostate cancer.
Study Findings
Among 507 veterans (141 Black, 313 White), adherence to relugolix exceeded 90% during the first 12 months of therapy. Median medication possession ratio (MPR) and proportion of days covered (PDC) remained high—around 99% at 3 months and approximately 90% at 12 months—with no significant racial differences.
Treatment Discontinuation and Switching
Over a median follow-up of 10.7 months for Black and 12.6 months for White patients:
- 27.0% of Black and 21.1% of White veterans discontinued relugolix.
- 9.2% of Black and 3.8% of White patients switched to another ADT.
- Adjusted analyses showed Black patients had a significantly higher risk of discontinuation (HR 1.61; 95% CI 1.04–2.49) and switching (HR 2.65; 95% CI 1.06–6.66).
PSA Responses Comparable Across Races
Among 130 ADT-naïve patients with evaluable PSA data:
- 87.2% of both Black and White patients achieved ≥50% PSA decline.
- 69.2% of Black and 64.1% of White patients achieved ≥90% decline.
- 51.3% of Black and 47.4% of White patients reached PSA <0.2 ng/mL.
These real-world PSA responses align with clinical trial findings.
Clinical Implications
The findings reinforce relugolix as a highly adherent and effective ADT option in real-world US veteran populations. For clinicians, the data offer reassurance that the once-daily oral regimen maintains adherence levels similar to those observed in controlled trials—important for achieving sustained castration and minimizing gaps in androgen suppression.
High adherence likely reflects factors such as ease of oral administration, reduced need for clinic visits, and favorable tolerability. The robust PSA responses indicate that relugolix performs consistently outside trial environments, supporting its use as first-line ADT—either as monotherapy or in combination with androgen receptor pathway inhibitors.
Racial disparities in treatment persistence warrant attention. Although adherence and PSA response were similar, the higher discontinuation and switching rates among Black patients may reflect broader social or structural determinants not captured in administrative datasets. These findings highlight opportunities for targeted interventions, including enhanced care coordination, patient support programs, or strategies addressing access barriers within the veteran population.
Conclusion
Relugolix demonstrated high adherence and strong PSA responses among veterans with prostate cancer, with similar clinical performance across racial groups. Although Black patients were more likely to discontinue or switch therapy, the underlying drivers require further investigation. Longer-term studies are needed to evaluate outcomes and optimize equitable care delivery within and beyond the VHA system.
Reference
Freedland SJ, Ramaswamy K, Kavati A, et al. Retrospective analysis of racial differences in treatment patterns and prostate-specific antigen responses among patients with prostate cancer treated with relugolix in the Veterans Health Administration. Adv Ther. 2025 Dec;42(12):6278-6294. doi:10.1007/s12325-025-03390-6.
