Can Relugolix Be Used in Non-Advanced Prostate Cancer?
No, relugolix is specifically indicated for advanced prostate cancer only and should not be used in non-advanced disease settings. The evidence clearly restricts its use to advanced hormone-sensitive prostate cancer where androgen deprivation therapy (ADT) is indicated.
Regulatory Indication and Evidence Base
- Relugolix is FDA-approved exclusively for advanced prostate cancer, with the European indication specifying "advanced hormone-sensitive prostate cancer" 1, 2.
- The pivotal HERO trial that established relugolix's efficacy enrolled only men with advanced prostate cancer requiring ADT, demonstrating sustained castration rates >90% over 48 weeks 1, 2.
- Current guidelines from ASCO (2021) and ESMO (2023) address relugolix only in the context of advanced disease requiring castration therapy 1.
What Constitutes "Advanced" Disease Where Relugolix Is Appropriate
Relugolix should be considered for:
- Metastatic hormone-sensitive prostate cancer (mHSPC) - where ADT forms the backbone of treatment, often combined with novel hormonal agents or docetaxel 1, 3.
- Locally advanced nonmetastatic disease in patients who have undergone radiotherapy or those unwilling/unable to undergo radiotherapy and requiring immediate ADT 1.
- Castration-resistant prostate cancer (CRPC) - both metastatic and non-metastatic high-risk disease where continued testosterone suppression is required 1.
Why Not Use Relugolix in Non-Advanced Disease
- No clinical trial data supports relugolix use in localized prostate cancer, biochemically recurrent disease with low-risk features, or as adjuvant therapy following definitive local treatment 1.
- For low-risk biochemically recurrent nonmetastatic prostate cancer, ASCO guidelines recommend active surveillance rather than any form of ADT 1.
- For high-risk biochemically recurrent disease, if ADT is chosen, intermittent ADT may be preferred over continuous suppression, but relugolix has not been studied in intermittent protocols 1, 3.
Clinical Advantages When Used Appropriately in Advanced Disease
When relugolix is used correctly in advanced prostate cancer:
- Superior cardiovascular safety profile compared to leuprolide, with 54% lower incidence of major adverse cardiovascular events (HR 0.46,95% CI 0.24-0.88) 1, 4, 5.
- No testosterone flare upon initiation, avoiding potential tumor flare complications seen with LHRH agonists 2, 4, 5.
- Rapid testosterone recovery after discontinuation, which may reduce ADT-related adverse events 5.
- Oral administration offers convenience compared to injectable depot formulations 2, 5.
Combination Therapy in Advanced Disease
- Relugolix can be safely combined with novel hormonal therapies (abiraterone, apalutamide, enzalutamide) or chemotherapy (docetaxel) in advanced disease without affecting efficacy or introducing new safety concerns 6, 7.
- These combinations are appropriate only when the underlying indication is advanced prostate cancer requiring intensified systemic therapy 8, 3.
Critical Pitfall to Avoid
Do not prescribe relugolix for early-stage, localized, or low-risk disease. The drug's indication, regulatory approval, and evidence base are restricted to advanced disease where ADT is clearly warranted. Using it outside this context exposes patients to unnecessary side effects of testosterone suppression without proven benefit 1, 2.