A Phase 2 interventional study of relugolix + ARPI and Intermittent- Relugolix or androgen deprivation therapy (ADT) + ARPI in Metastatic Hormone-sensitive Prostate Cancer (mHSPC), sponsored by University of Utah. Recruiting at 1 site in United States. Open to male participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-06-23.
Sponsored by University of Utah · Phase 2, Interventional, and Treatment
The purpose of this study is to evaluate intermittent relugolix + androgen receptor pathway inhibitor (ARPI) in patients with metastatic hormone-sensitive prostate cancer (mHSPC) achieving optimal PSA response.
University of Utah is the lead sponsor of 969 studies on the registry; 178 are open to participants now.
Of its 107 completed or terminated interventional studies of FDA-regulated products, 62 (58%) have results posted.
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Cohort A Eligibility (Step 1 Registration)
Participants with a sexual partner of childbearing potential must agree to use a highly effective method of contraception requirements as described in Section 5.5.1.
Cohort A Eligibility (Step 2 Registration) -PSA ≤ 0.2 ng/mL after 6-12 months of relugolix and androgen receptor pathway inhibitor treatment. Androgen receptor pathway inhibitor includes abiraterone, enzalutamide, apalutamide, darolutamide or similar drugs.
Cohort B Eligibility
Participants with a sexual partner of childbearing potential must agree to use a highly effective method of contraception requirements as described in Section 5.5.1.
Exclusion Criteria:
Cohort A Eligibility (Step 1 Registration)
Known brain metastases or cranial epidural disease.
--Note: Brain metastases or cranial epidural disease adequately treated with radiotherapy and/or surgery and stable for at least 4 weeks before the first dose of study treatment will be allowed on trial. Participants must be neurologically stable and receiving a stable or decreasing corticosteroid dose at the time of study entry.
Cohort A Eligibility (Step 2 Registration)
Cohort B Eligibility
Known brain metastases or cranial epidural disease.
--Note: Brain metastases or cranial epidural disease adequately treated with radiotherapy and/or surgery and stable for at least 4 weeks before the first dose of study treatment will be allowed on trial. Participants must be neurologically stable and receiving a stable or decreasing corticosteroid dose at the time of study entry
INDUCTION (Step 1): Participants will receive continuous treatment with relugolix + an androgen receptor pathway inhibitor (ARPI). After 6-12 months of continuous treatment, participants whose PSA is ≤ 0.2 ng/mL and who have completed step two registration will be randomized to one of two treatment arms: • Cohort A: Arm 1 will continue standard-of-care, continuous treatment with relugolix or androgen deprivation therapy (ADT) + ARPI per clinical investigator.
Drug: relugolix + ARPI · Drug: relugolix or androgen deprivation therapy (ADT) + ARPI
INDUCTION (Step 1): Participants will receive continuous treatment with relugolix + an androgen receptor pathway inhibitor (ARPI). After 6-12 months of continuous treatment, participants whose PSA is ≤ 0.2 ng/mL and who have completed step two registration will be randomized to one of two treatment arms: • Cohort A: Arm 2 will receive intermittent treatment with relugolix + ARPI.
Drug: relugolix + ARPI · Drug: relugolix + ARPI.
Participants who have achieved PSA ≤ 0.2 ng/mL are eligible and will receive intermittent treatment with relugolix + ARPI.
Drug: Intermittent- Relugolix or androgen deprivation therapy (ADT) + ARPI
Step 1: Continuous treatment with relugolix + ARPI
Intermittent treatment with relugolix + ARPI.
Step 2: Standard-of-care, continuous treatment with relugolix or androgen deprivation therapy (ADT) + ARPI.
Step 2: Intermittent treatment with relugolix + ARPI.
Cohort A: Brief Fatigue Inventory (BFI) score 6 months after randomization.
To assess the difference in fatigue 6 months after randomization in patients with mHSPC achieving optimal PSA response on intermittent relugolix + ARPI versus continuous relugolix/ADT + ARPI. Scored from 0 (no Fatigue) to 10 (as bad as you can imagine), and 0 (Does not interfere) to 10 (Completely Interferes).
Time frame: 6 months
Cohort B: Progression-free survival (PFS) as defined as the time from intermittent study initiation (first treatment break) to the time of documented disease progression or death from any cause at one year.
To assess PFS in patients with mHSPC on intermittent relugolix/ADT + ARPI at one year.
Time frame: 12 months
Changes in health-related quality of life as measured by the European Organisation for Research and Treatment of Cancer Quality of Life Core Questionnaire (EORTC-QLQC30).
To evaluate treatment effects on patient-reported outcomes (PROs). EORTC-QLQC30 scored from 1 (not at all)- 4 (very much).
Time frame: 13 months
Changes in health-related quality of life as measured by the European Organisation for Research and Treatment of Cancer Quality of Life Core Questionnaire (EORTC-QLQ-PR25).
To evaluate treatment effects on patient-reported outcomes (PROs). EORTC-QLQ-PR25 scored from 1 (not at all)- 4 (very much).
Time frame: 13 months
Sexual function improvement in those with intact sexual function at baseline as measured by the European Organisation for Research and Treatment of Cancer Quality of Life Core Questionnaire.
To evaluate treatment effects on patient-reported outcomes (PROs). EORTC-QLQ-PR25, question 52-55.Scored from 1 (not at all)- 4 (very much).
Time frame: 13 months
Changes in severity of hot flashes as measured by the Hot Flash Related Daily Interference Scale (HFRDIS).
To evaluate treatment effects on patient-reported outcomes (PROs). HFRDIS scored 0 (did not interfere to 10 (completely interfered).
Time frame: 13 months
Changes in cognitive function as measured by the PROMIS-Cognitive function Short Form 8a.
To evaluate treatment effects on patient-reported outcomes (PROs). PROMIS-Cognitive function Short Form 8a scored 5 (Never)- 1 (very often- Several times a day).
Time frame: 13 months
Change from baseline over time in each PRO, including time to recovery and deterioration in the intermittent arm with treatment break and start.
To evaluate treatment effects on patient-reported outcomes (PROs).
Time frame: 2 years
Time to metastatic castration-resistant prostate cancer.
Cohort A: To determine if intermittent relugolix + ARPI will provide similar efficacy as continuous relugolix/ADT + ARPI in clinically relevant endpoints in participants with mHSPC who reached PSA ≤0.2 ng/mL after 6-12 months of relugolix+ARPI treatment. Cohort B: To evaluate the treatment efficacy of intermittent relugolix/ADT + ARPI.
Time frame: 12 months
Overall survival and prostate cancer-specific survival at 3 years from the date of randomization.
Cohort A: To determine if intermittent relugolix + ARPI will provide similar efficacy as continuous relugolix/ADT + ARPI in clinically relevant endpoints in participants with mHSPC who reached PSA ≤0.2 ng/mL after 6-12 months of relugolix+ARPI treatment. Cohort B: Change from baseline over time in each PRO, including time to recovery and deterioration in intermittent arm with treatment break and start.
Time frame: 12 months
Time to systemic treatment change.
To determine if intermittent relugolix + ARPI will provide similar efficacy as continuous relugolix/ADT + ARPI in clinically relevant endpoints in participants with mHSPC who reached PSA ≤0.2 ng/mL after 6-12 months of relugolix+ARPI treatment
Time frame: 12 months
Duration of time on treatment
Cohort A: To determine if intermittent relugolix + ARPI will provide similar efficacy as continuous relugolix/ADT + ARPI in clinically relevant endpoints in participants with mHSPC who reached PSA ≤0.2 ng/mL after 6-12 months of relugolix+ARPI treatment. Cohort B: To evaluate the treatment efficacy of intermittent relugolix/ADT + ARPI.
Time frame: 12 months
Time to first treatment restart
Cohort A: To determine if intermittent relugolix + ARPI will provide similar efficacy as continuous relugolix/ADT + ARPI in clinically relevant endpoints in participants with mHSPC who reached PSA ≤0.2 ng/mL after 6-12 months of relugolix+ARPI treatment. Cohort B: To evaluate the treatment efficacy of intermittent relugolix/ADT + ARPI.
Time frame: 12 months
Duration of time with testosterone < 50 ng/mL
Cohort A: To determine if intermittent relugolix + ARPI will provide similar efficacy as continuous relugolix/ADT + ARPI in clinically relevant endpoints in participants with mHSPC who reached PSA ≤0.2 ng/mL after 6-12 months of relugolix+ARPI treatment. Cohort B: To evaluate the treatment efficacy of intermittent relugolix/ADT + ARPI.
Time frame: 12 months
Testosterone-linked outcomes (time to recovery of testosterone ≥50 ng/dL; time to recovery of testosterone to baseline [≥screening testosterone level]).
Cohort A: To determine if intermittent relugolix + ARPI will provide similar efficacy as continuous relugolix/ADT + ARPI in clinically relevant endpoints in participants with mHSPC who reached PSA ≤0.2 ng/mL after 6-12 months of relugolix+ARPI treatment. Cohort B: To evaluate the treatment efficacy of intermittent relugolix/ADT + ARPI.
Time frame: 12 months
Duration of time to recovery of testosterone to normal range [>300 ng/dL]).
Cohort A: To determine if intermittent relugolix + ARPI will provide similar efficacy as continuous relugolix/ADT + ARPI in clinically relevant endpoints in participants with mHSPC who reached PSA ≤0.2 ng/mL after 6-12 months of relugolix+ARPI treatment. Cohort B: To evaluate the treatment efficacy of intermittent relugolix/ADT + ARPI.
Time frame: 12 months
The proportion of participants achieving a treatment-free interval (TFI) of at least one year from the time of registration and median TFI.
To assess the TFI at one year in patients achieving optimal PSA response.
Time frame: 12 months
Change in Brief Fatigue Inventory (BFI) score from baseline to 6 months after registration.
To assess the change in quality of life measures from baseline. BFI Scored from 0 (no Fatigue) to 10 (as bad as you can imagine), and 0 (Does not interfere) to 10 (Completely Interferes).
Time frame: 6 months
Changes in cognitive function as measured by the PROMIS-Cognitive Function Short Form 8a.
To assess the change in quality of life measures from baseline. PROMIS-Cognitive function Short Form 8a scored 5 (Never)- 1 (very often- Several times a day).
Time frame: 13 months
Change from baseline over time in each PRO, including time to recovery and deterioration in intermittent arm with treatment break and start.
To assess the change in quality of life measures from baseline.
Time frame: 13 months
Overall survival and prostate cancer specific survival at 3 years from the date of randomization.
To evaluate the treatment efficacy of intermittent relugolix + ARPI.
Time frame: 3 years
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