NCT07354594 External Beam and Radioligand Radiotherapy for mCRPC
| NCT ID | NCT07354594 |
| Status | Recruiting |
| Phase | Phase 2 |
| Sponsor | Centre hospitalier de l'Université de Montréal (CHUM) |
| Condition | Prostate Cancer Metastatic Castration-Resistant |
| Study Type | INTERVENTIONAL |
| Enrollment | 120 participants |
| Start Date | 2026-07-07 |
| Primary Completion | 2028-05 |
Eligibility & Interventions
Eligibility Fast-Check
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What to Expect as a Participant
You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.
In Phase 2, researchers evaluate early signs of effectiveness. You may be randomized to receive the active treatment or a comparator. Monitoring continues closely.
This trial targets 120 participants in total. It began in 2026-07-07 with a primary completion date of 2028-05.
⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.
Brief Summary
Prostate-specific membrane antigen (PSMA)-targeted radioligand therapy with Lutetium-177 (¹⁷⁷Lu-PSMA) is an established treatment for metastatic prostate cancer. Administered intravenously, it enables targeted irradiation of PSMA-expressing tumor cells. However, 30-50% of patients derive limited benefit. This variability could be partly explained by heterogeneity in delivered dose across lesions, leading to under-treatment of certain metastases. The addition of targeted external beam radiotherapy (EBRT) may compensate for this underdosing by delivering a precise dose to insufficiently irradiated lesions. The investigators hypothesize that the addition of adaptive EBRT to ¹⁷⁷Lu-PSMA will reduce the incidence of skeletal-related events (pathologic fracture, spinal cord compression, surgery, or palliative radiotherapy) without increasing toxicity. Adaptive EBRT and RLT for mCRPC (ARREST) is a pragmatic registry-based phase 2, multi-center randomized controlled trial within the PERa prospective cohort (NCT03378856) planned to activate in 2026. Patients receiving standard-of-care (SOC) ¹⁷⁷Lu-PSMA with targetable metastatic burden identified on imaging and suitable for EBRT will be eligible. One hundred and twenty eligible patients will be randomized 1:1 to receive either SOC ¹⁷⁷Lu-PSMA therapy alone (maximum 6 cycles) or combined ¹⁷⁷Lu-PSMA plus adaptive EBRT. Patients in the experimental arm will undergo FDG-PET at study entry and SPECT-CT after each cycle of radioligand therapy. Lesions selected for EBRT boost will be chosen based on a set of criteria that include estimated suboptimal absorbed dose from ¹⁷⁷Lu-PSMA, lesions demonstrating low PSMA but high FDG uptake, symptomatic lesions, and lesions at high risk for skeletal-related events. Selected lesions will receive single-fraction EBRT. The prescribed dose will range from 6-12 Gy, with the goal of achieving a combined total biological effective dose of ≥50 Gy (α/β = 5), while prioritizing dose limits for organs at risk. A maximum treatment time of 60 minutes is permitted for each adaptive EBRT treatment. Patients in the experimental arm who achieve a complete response, as measured by ¹⁷⁷Lu-SPECT-CT and PSA, will pause ARREST treatment and resume at disease progression. The primary endpoint is skeletal-related events at 1 year. Secondary objectives include overall survival, ¹⁷⁷Lu-SPECT-CT and PSA response, toxicity, and quality of life. The sample size is designed to detect a 12-month improvement in the rate of skeletal-related events with a hazard ratio of 0.61, a one-sided alpha of 0.1, and 80% power. ARREST is expected to safely optimize tumor dose, offering a personalized hybrid approach that may lead to improved patient outcomes. In addition, this study will permit further understanding of these two distinct radiation delivery methods and their effects on tissues, thereby refining the relative biological effectiveness model for more precise treatment planning.
Eligibility Criteria
Inclusion Criteria: * Receiving 177Lu-PSMA for mCRPC * ECOG 0-1 * Presence of a discernible metastatic burden suitable for EBRT * Receiving bone protective therapy Exclusion Criteria: * no exclusions
Contact & Investigator
Cynthia Menard, MD
PRINCIPAL INVESTIGATOR
Centre hospitalier de l'Université de Montréal (CHUM)
Frequently Asked Questions
Who can join the NCT07354594 clinical trial?
This trial is open to male participants only, studying Prostate Cancer Metastatic Castration-Resistant. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.
What phase is the NCT07354594 trial and what does that mean for participants?
Phase 2 trials evaluate whether the treatment shows signs of effectiveness while continuing to monitor safety. More participants are enrolled than in Phase 1 to help refine the treatment protocol.
Is NCT07354594 currently recruiting?
Yes, NCT07354594 is actively recruiting participants. Contact the research team at mom.phat.chum@ssss.gouv.qc.ca for enrollment information.
Where is the NCT07354594 trial being conducted?
This trial is being conducted at Montreal, Canada.
Who is sponsoring the NCT07354594 clinical trial?
NCT07354594 is sponsored by Centre hospitalier de l'Université de Montréal (CHUM). The principal investigator is Cynthia Menard, MD at Centre hospitalier de l'Université de Montréal (CHUM). The trial plans to enroll 120 participants.
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