Ablative Radiotherapy to Consolidate Maximal Systemic Response in Metastatic Prostate Cancer (ANCHOR-Prostate) (ANCHORProstate)

This will be a pragmatic, phase II, registry-based cohort-multiple randomized controlled trial (cmRCT) embedded within an ongoing prospective cancer radiotherapy registry. Eligible patients are those with hormone-sensitive metastatic prostate cancer who have responded to systemic therapy, defined by the absence of PSA progression, and who are eligible for MDRT. All eligible subjects will be enrolled into the registry and followed longitudinally for oncologic and toxicity outcomes.

From this registry, patients will be randomly selected (1:1) to be offered the experimental arm, which consists of MDRT delivered to metastatic sites identified on imaging in patients who have already initiated systemic therapy (Figure 1). Those not selected will continue to receive standard of care systemic therapy +/- standard of care radiotherapy if clinically indicated. Nor patients or physicians will be blinded.

Following the initial course of MDRT, prostate-specific antigen (PSA) will be measured, with a minimum assessment at 3 months. This PSA value will be used to determine whether the PSA level has decreased below 0.2 ng/mL. If the PSA remains ≥ 0.2 ng/mL, repeat PSMA-PET will be performed, and a second course of MDRT will be delivered to consolidate residual metastatic lesions.

In this phase II real-world randomized trial, we will determine if AnChoRing (Addition of MDRT for consolidation of response) sites of PSMA PET visible disease when responding to systemic therapy improves the proportion of patients achieving a PSA < 0.2 ng/mL and extends failure-free survival compared to the standard of care.

Study Overview

• Status: Recruiting
• Conditions: Prostate Cancer Metastatic
• Intervention / Treatment: Radiation: Metastasis directed radiotherapy (MDRT); Other: no MDRT

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Mom Phat; Phone Number: 514-890-8254; Email: mom.phat.chum@ssss.gouv.qc.ca

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada, H2X 0A9
      • Recruiting
      • CRCHUM
      • Principal Investigator: Cynthia Menard, MD
      • Contact: Mom Phat; Phone Number: 514-890-8254; Email: mom.phat.chum@ssss.gouv.qc.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Enrolled in PERa (CHUM CER 17.032) and randomly selected for ANCHOR-Prostate.
• Diagnosis of hormone-sensitive metastatic prostate cancer having responded to systemic therapy.
• PSA non-progressing
• ECOG 0-2
• Metastatic disease suitable for MDRT.
• Primary tumor must have received definitive local treatment (surgery or radiotherapy) with no evidence of local recurrence, or be planned for treatment at the time of MDRT.

Exclusion Criteria:

• Planned intermittent systemic therapy.
• Planned radio-ligand therapy.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: MDRT consolidation	Radiation: Metastasis directed radiotherapy (MDRT); MDRT to PSMA-PET visible disease at systemic therapy response.
Active Comparator: Control - no MDRT consolidation	Other: no MDRT; Continue systemic therapy per standard of care

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
PSA Response	Defined as the proportion of patients achieving a PSA of < 0.2 ng/mL at 12 months post-randomization.	12 months
Failure Free Survival (FFS)	FFS is defined as time from randomization to the first of the following events: PSA progression, initiation of next-line systemic therapy, radiographic or clinical progression.	3 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to progression		5 years
HRQoL		5 years
Toxicity	CTCAEv5, incidence rate	5 years

Collaborators and Investigators

• Sponsor: Centre hospitalier de l'Université de Montréal (CHUM)

Study record dates

Study Major Dates

• Study Start (Actual): December 30, 2022
• Primary Completion (Estimated): July 30, 2030
• Study Completion (Estimated): July 30, 2030

Study Registration Dates

• First Submitted: July 4, 2022
• First Submitted That Met QC Criteria: July 11, 2022
• First Posted (Actual): July 14, 2022

Study Record Updates

• Last Update Posted (Actual): April 8, 2026
• Last Update Submitted That Met QC Criteria: April 2, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Genital Diseases, Male; Prostatic Diseases; Male Urogenital Diseases; Prostatic Neoplasms
• Other Study ID Numbers: 22.115

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No