Strategic Endocrine Therapy and Targeted Radiotherapy for Prostate Cancer (SENTRY)

January 24, 2026 updated by: Tyler Seibert, University of California, San Diego

Strategic ENdocrine and Targeted Radiation therapY

The goal of this clinical trial is to study definitive external beam radiation therapy together with drugs called androgen deprivation therapy (ADT) in patients with prostate cancer. The investigators want to find out if these drugs work the same way if they are given for 6 months or for the usual 18 months in patients who receive also definitive external beam radiotherapy. The investigators will also learn about the safety of the treatments. The main questions the study aims to answer are:

Do patients who get radiation therapy plus 6 months of androgen deprivation therapy need other hormone therapy or develop castration resistance at a higher rate within 5 years, compared to patients who get radiation therapy plus 18 months of androgen deprivation therapy?

Participants will:

Be treated with definitive external beam radiation therapy and receive androgen deprivation therapy for 6 months or 18 months.

Have visits once every 3 months for checkups and tests for at least 5 years. The visits at 3 months, 1 year, and 5 years need to be done in person; all the other visits can be done in person or remotely (telehealth).

Keep a diary of the missed doses of the androgen deprivation therapy.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Definitive radiation therapy combined with hormone therapy improves oncologic outcomes in patients with high-risk prostate cancer. However, hormone therapy has substantial toxicity, including metabolic and cardiovascular, and negatively impacts quality-of-life. Previous trials demonstrated that long-term hormone therapy lasting 18-36 months improved overall survival compared to short-term hormone therapy lasting only 4-6 months. However, long-term hormone therapy also extends the duration of treatment-related toxicity. There is great interest among patients and physicians to reduce the total treatment time. A trial studying shorter duration of hormone therapy is warranted for the following reasons.

First, the trials that established the benefits of long-term hormone therapy were conducted over 20 years ago. Since then, advances in staging imaging and image-guided biopsy techniques have led to major stage migration in prostate cancer that has improved the prognosis of patients with disease categorized as high risk but localized. Second, substantial improvements in radiotherapy techniques have made it possible to deliver higher, more ablative radiation doses to the tumor while sparing normal organs. Third, even recurrent disease after definitive radiotherapy can now be detected early and managed with advanced radiotherapy (stereotactic ablative radiotherapy) to delay a need for salvage hormone therapy. Fourth, recent randomized trials have demonstrated that combining conventional androgen-deprivation therapy - usually accomplished with a gonadotropin-releasing hormone agonist or antagonist - with an androgen receptor pathway inhibitor is safe and improves overall survival in advanced prostate cancer.

These advances suggest that modern radiotherapy combined with short-term androgen deprivation therapy - and an optional androgen receptor pathway inhibitor - may achieve outcomes comparable to radiotherapy with long-term androgen deprivation therapy. This strategy offers the potential to maintain tumor control, reduce treatment-related morbidity, and improve patient survivorship. This randomized trial will compare the efficacy and toxicity of this novel treatment approach against the current standard of care. The investigators hypothesize that the novel treatment approach will have excellent disease control - comparable to that achieved with traditional long term androgen deprivation therapy - while improving quality of life.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
150

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

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

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Histologically confirmed adenocarcinoma of the prostate.

  2. High-risk localized prostate cancer, defined as ≥1 of the following (per National Comprehensive Cancer Network or D'Amico criteria):

    1. Prostate specific antigen ≥ 20 ng/mL
    2. Gleason score 8-10
    3. Clinical stage T3a or higher; imaging can be used to determine T stage if there is macroscopic (gross) extraprostatic extension or invasion of the seminal vesicles or other non-prostate organs

  3. No evidence of distant metastasis, confirmed by:

    a. Prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) or equivalent staging imaging

  4. Planning to receive definitive external beam radiotherapy and hormone therapy as standard of care (on label or medically accepted) treatment
  5. Eastern Cooperative Oncology Group performance status 0-1.
  6. Age ≥ 18 years.
  7. Willingness to use adequate contraception if sexually active and of reproductive potential
  8. Ability to understand and willingness to sign informed consent.
  9. Stated willingness to comply with all study procedures and availability for the duration of the study.

Exclusion Criteria:

  1. Evidence of metastatic disease, including nodal disease beyond the pelvis or distant metastases on imaging.
  2. Clear evidence of regional nodal disease on conventional imaging.
  3. Prior prostatectomy.

  4. Prior systemic therapy for prostate cancer, including:

    1. Androgen deprivation therapy (Note that participants who have started Androgen deprivation therapy within 90 days prior to randomization can be enrolled.)
    2. Androgen receptor pathway inhibitor (e.g., abiraterone, enzalutamide, apalutamide, darolutamide).
    3. Chemotherapy for prostate cancer.
  5. Prior pelvic radiotherapy.
  6. Any condition that, in the investigator's judgment, would compromise the patient's safety or compliance.

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: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: RT + ST-ADT
Radiotherapy with short-term androgen deprivation therapy (6 months) plus, if indicated, an androgen receptor pathway inhibitor.
Radiation: Radiation therapy
Radiotherapy with short-term androgen deprivation therapy plus, if indicated, an androgen receptor pathway inhibitor.
Active Comparator: RT + LT-ADT
Radiotherapy with long-term androgen deprivation therapy (18 months).
Radiation: Radiation therapy
Radiotherapy with short-term androgen deprivation therapy plus, if indicated, an androgen receptor pathway inhibitor.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Failure-free survival
Time Frame: Within 5 years

To compare failure-free survival of radiotherapy plus short-term androgen deprivation therapy plus, if indicated, an androgen receptor pathway inhibitor to that of radiotherapy plus long-term androgen deprivation therapy.

Participants will be considered to have failure-free survival if they do not experience any of the events in the 5 years after the end of radiation therapy:

  1. Death from any cause.
  2. Initiation of salvage hormone therapy as defined in the protocol.
  3. Castration resistance per the Prostate Cancer Clinical Trials Working Group 3 definition. Castration resistance is defined as biochemical or clinical progression - as defined in the protocol - while serum testosterone is at castrate levels (<50 ng/dL).
Within 5 years

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of California, San Diego

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Lantheus

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Tyler Seibert, MD, PhD, University of California, San Diego

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 1, 2031

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 1, 2034

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 15, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 15, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 23, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 27, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 24, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 813314

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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.

Clinical Trials on Prostate Adenocarcinoma

Clinical Trials on Radiation therapy

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings