Response With Interim PSMA PET in Metastatic Castration-sensitive Prostate Cancer for Optimization of Adaptive Metastasis-directed Radiotherapy Delivery (RIPCORD)

August 20, 2026 updated by: Daniel Yang, University of Texas Southwestern Medical Center
The purpose of this study is to characterize the reduction in PSMA-avid tumor volume and metastasis-directed radiotherapy treatment intensity facilitated by PET PSMA-response adapted SABR for poly-metastatic castration sensitive prostate cancer.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

This study will enroll patients with poly-metastatic hormone-sensitive prostate cancer, as identified by baseline PSMA PET imaging. All participants will undergo standard of care systemic therapy, including ADT and androgen receptor signaling inhibitors intensification as clinically indicated, for up to three months before protocol radiotherapy. The treating radiation oncologist will pre-plan SABR to a total of 35-40 Gy in 5 fractions. The study will consist of initially delivering three qWeekly SABR "pulses" to all identified metastatic sites. The initial pulse should start within 60 (+/-30 days) of initiation of ADT. Following the third pulse, interim PSMA PET imaging will be repeated at 6 months from initiation of ADT (-30 days allowed) to evaluate the response on a per lesion basis (See Section 6.1.2.1). In the absence of a complete response (CR) for a given lesion, two additional qWeekly pulses may be delivered to these sites within 60 days from interim PSMA PET. PSMA avid lesions identified at baseline will be monitored on interim and follow up scan, and new PSMA avid lesions will require confirmation through conventional imaging. If patients exhibit progression on PSA or conventional imaging, they will exit the trial and undergo systemic therapy intensification. More detailed specifications on systemic therapy and SABR and their parameters are provided in the protocol.

Study Type

Interventional

Enrollment (Estimated)

30

Phase

  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. History of pathologically confirmed prostate cancer.
  2. Age >=18 years.
  3. Performance status ECOG 0-2.
  4. Staging 68Ga PMSA-11 PET/CT showing 4-20 sites of metastasis from prostate cancer within <=90 days prior to registration. This scan ideally should be performed before initiation of androgen deprivation therapy (ADT).
  5. At the discretion of the treating investigator, it is believed that it is safe to treat all sites of disease using SABR.
  6. All men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, for the duration of standard of care SABR and for a period of time of 6 months thereafter as per standard guidelines. Should a patient's partner become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.
  7. Ability to understand and the willingness to sign a written informed consent.
  8. Planned for standard systemic therapy for metastatic prostate cancer to include androgen deprivation therapy (ADT). Upfront Docetaxel should not be planned (See section 4.1.2).

Exclusion Criteria:

  1. Prior radiotherapy to any metastases currently targeted for therapy or overlapping regions.
  2. Patient with metastatic lesions involving the gastrointestinal tract, specifically, invading esophagus, stomach, or intestines will be excluded. Patients with ultra-central metastatic lesions defined as 1 cm from the trachea and main bronchi will be excluded.
  3. Serious medical co-morbidities precluding safe delivering of radiotherapy to poly-metastatic sites. This includes interstitial lung disease for patients undergoing SABR to thoracic sites and ulcerative colitis or Crohn's disease requiring systemic immunosuppressive therapy for patients undergoing SABR to GI sites.
  4. Subjects may not be receiving any other PSMA-directed investigational agents for the treatment of the cancer under study.
  5. History of allergic reactions to PMSA-11 68Ga imaging agent.
  6. Uncontrolled intercurrent illness or psychiatric illness/social situations that, in the opinion of the investigator, would limit compliance with study requirements.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: SINGLE ARM UNBLINDED SINGLE SITE PILOT
Study will enroll patients with poly-metastatic hormone-sensitive prostate cancer, as identified by baseline PSMA PET imaging.Patients will undergo standard of care systemic therapy,including ADT & androgen receptor signaling inhibitors intensification as clinically indicated,for up to 3 months before protocol radiotherapy.
Drug: Drug: 68-Ga PSMA11

0-3 months since initiation of ADT. Baseline PSMA PET imaging. 4-20 sites of metastasis by PSMA PET Will be injected/assessed in line with its FDA label.

Other Name:

Radiation: Adaptive stereotactic ablative radiotherapy (SABR)
Pre-plan 5 fraction SABR 35-40 Gy. SOC systemic therapy allows for ADT and ARSI intensification. Delivery of 3 pulses to all sites. Pulses delivered weekly.
Drug: 68Ga-PSMA-11
Repeat PSMA PET imaging at 6 months post-ADT initiation. Radiation of primary allows. Will be injected/assessed in line with its FDA label.
Radiation: Adaptive stereotactive ablative radiotherapy (SABR)
Delivery of 2 additional pulses to all remaining PSMA PET visible sites

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Reduction in PSMA-positive TTV
Time Frame: 1 YEAR
will be measured by the decrease in TTV (%) on a per-patient basis between the initial scan and post-SABR PSMA PET.
1 YEAR
Reduction in SABR treatment intensity
Time Frame: 1 YEAR
Will be measured by the decrease in proportion of tumor lesions treated to initially prescribed 5 fractions (%) due specifically to complete metabolic response on interim PET PSMA after 3 fractions, as compared to initially planned lesions on a per patient basis.
1 YEAR

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Texas Southwestern Medical Center

Collaborators

Varian, a Siemens Healthineers Company
Telix Pharmaceuticals (Innovations) Pty Ltd

Investigators

  • Principal Investigator: DANIEL YANG, MD, University of Texas Southwestern Medical Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2026

Primary Completion (Estimated)

June 15, 2029

Study Completion (Estimated)

June 15, 2029

Study Registration Dates

First Submitted

June 24, 2026

First Submitted That Met QC Criteria

June 24, 2026

First Posted (Actual)

June 30, 2026

Study Record Updates

Last Update Posted (Actual)

August 24, 2026

Last Update Submitted That Met QC Criteria

August 20, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STU 20260850

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

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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