NCT05269550: ARGOS/CLIMBER

PSMA MRI Guided Prostate SBRT (ARGOS)/Comprehensive, Longitudinal Evaluation of Imaging Biomarkers Post Radiotherapy (CLIMBER)

Active, enrolled NA Last updated 28 July 2025

What this trial tests

NA trial testing High-Intermediate Risk Patients-cohort 1 in Prostate Cancer in 50 participants. Participants enrolled and being followed up; not accepting new ones.

Timeline

3 May 2022

Primary endpoint
15 December 2028

15 December 2028

Quick facts

Lead sponsor	London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's
Phase	NA
Status	Active, enrolled
Study type	INTERVENTIONAL
Allocation	na
Design	single group
Masking	none
Primary purpose	treatment
Enrollment	50
Start date	3 May 2022
Primary completion	15 December 2028
Estimated completion	15 December 2028
Sites	2 locations across Canada

Drugs / interventions tested

• High-Intermediate Risk Patients-cohort 1
• High Risk or Very High-Risk Patients-cohort 1
• High-Intermediate Risk Patients-cohort 2
• High Risk or Very High-Risk Patients-cohort 2

Conditions studied

• Prostate Cancer — all drugs for Prostate Cancer →

Sponsor

London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's

Who can join

18 and older, male only, with Prostate Cancer. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

This study is a prospective Phase I/II protocol enrolling men with either high intermediate-risk or high-risk or very high-risk prostate cancer. All men will have PSMA Targeted PET (using the PSMA targeting ligand PSMA 1007) and multiparametric magnetic resonance imaging (mpMRI) for delineation of intra-prostatic foci of cancer and any involved regional lymph nodes based on high SUV uptake on PET or mpMRI (T2W, DWI/ADC, DCE) appearance suspicious for cancer. Tumour delineation will be performed by fusing the PSMA PET and mpMRI with planning CT simulation images. Fiducial marker implantation for treatment guidance will be mandatory but use of other organs at risk protection strategies (i.e. GU Loc, Space-OAR) will be allowed but not mandatory. Patients will be treated with image-guided SBRT using the fiducial markers for intra-fraction motion management. Dose escalation to imaging defined targets (intra-prostatic and involved nodes on PSMA PET + MRI) will be accomplished through a simultaneous boost technique. Maintaining dose to organs at risk will take precedence over boost dose targets (targeted maximum dose of 50Gy/5 fractions to imaging defined prostatic lesion; 35Gy/5 fractions to imaging defined involved nodes).

Cohort extension: We hypothesize that integration of neoadjuvant androgen deprivation therapy will provide for pretreatment cancer downstaging and will allow us to achieve higher target doses to the imaging defined DILs than currently achieve. Additionally, we plan to include a novel sodium MRI protocol into the baseline imaging to compare DIL volumes delineated by this modality to those by mpMRI and PSMA PET and to characterize changes in sodium MRI in response to ADT alone and subsequent radiotherapy

Publications & conference data

3 peer-reviewed publications reference this trial (live from Europe PMC):

1. Imaging Biomarkers in Prostate Stereotactic Body Radiotherapy: A Review and Clinical Trial Protocol.
   Liu W, Loblaw A, Laidley D, Fakir H, et al · · 2022 · cited 2× · PMID 35494042 · DOI 10.3389/fonc.2022.863848
2. Different sodium concentrations of noncancerous and cancerous prostate tissue seen on MRI using an external coil.
   Tan JL, Kalia V, Pautler SE, Bauman G, et al · · 2024 · cited 1× · PMID 39574514 · DOI 10.1093/radadv/umae023
3. Analysis of Clinical Trials and Review of Recent Advances in Therapy Decisions for Locally Advanced Prostate Cancer.
   Williams NR. · · 2023 · cited 1× · PMID 37373928 · DOI 10.3390/jpm13060938