NCT06111781 · Yale University
The SUGAR Study; SBRT and Relugolix) for Prostate Cancer
What this study is about
The goal of this clinical trial is to measure the toxicity and effectiveness of the following treatments for cFIR/cgUIR prostate cancer patients. Stereotactic body radiotherapy (SBRT) alone or Stereotactic body radiotherapy (SBRT) combined with Ultrashort GNRH Antagonist called Relugolix (an taken by mouth drug). Treatments will be randomly assigned to study patients.
View original scientific description
The goal of this clinical trial is to measure the toxicity and effectiveness of the following treatments for cFIR/cgUIR prostate cancer patients. Stereotactic body radiotherapy (SBRT) alone or Stereotactic body radiotherapy (SBRT) combined with Ultrashort GNRH Antagonist called Relugolix (an oral drug). Treatments will be randomly assigned to study patients. The main questions it aims to answer are the following: 1.
Interventions
DRUG
Relugolix 120 MG [Orgovyx]
ORGOVYX will be initiated with a loading dose of 360 mg on the first day and continue treatment with a 120 mg dose taken orally once daily at approximately the same time each day. Total length of treatment will be 30 days.
RADIATION
SBRT standard of care radiotherapy treatment
SBRT is a standard-of-care radiotherapy treatment for intermediate-risk prostate cancer.
Primary outcome measures
Proportion of participants that attain PSA nadir
Time frame: up to 2 years post treatment
The proportion of men who undergo SUGAR that attain PSA nadir of \<= 0.2ng/mL compared to SBRT alone.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Provision of signed and dated informed consent form
- Stated willingness to comply with all study procedures and availability for the duration of the study
- Has histologically or cytologically confirmed diagnosis of adenocarcinoma of the prostate
- Born assigned to Male gender, age 18 and above. Female identifying transgender or gender fluid are allowed on study provided they have not undergone testosterone suppressing therapy and were born with a prostate.
- Has a serum testosterone at the Screening visit of \>100 ng/dL
- Has a serum PSA concentration at the Screening visit of \> 0.2 ng/mL
- Able to swallow pills and take medication orally (no documented inability to eat solids and swallow pills) and be willing to adhere to the daily regimen of medication (if assigned to the experimental arm).
- For patients of reproductive potential: use of condoms or other methods (including abstinence) to ensure effective contraception with partner during radiotherapy and through 4 months after the last dose of the study drug or radiotherapy
- Agreement to adhere to Lifestyle Considerations (see section 5.3) throughout study duration
- Clinical favorable intermediate risk prostate cancer: Gleason score must be Gleason 3+4 with a PSA \< 20 ng/mL, or Gleason 6 (3+3) and PSA \> 10 ng/mL and \< 20 ng mL.
- Decipher GC score of 0.6 or higher or higher indicating high genomic risk for most recent biopsy
- Documented prostate volume (by MRI or ultrasound within 120 days or physician attestation within 120 days) \<= 80 cc
Exclusion criteria
- Current use of medications that cause QT prolongation
- Known allergic reactions to relugolix
- Treatment with another investigational drug or other intervention for prostate cancer within 30 days of enrollment
- Ulcerative colitis or other inflammatory bowel disease history
- Connective tissue disease such as lupus, scleroderma, or dermatomyositis
- GNRH antagonist therapy or SBRT to the prostate are medically contraindicated or not tolerated
- History of long QT syndrome documented in the medical record
- The following ECG abnormalities are excluded:
- Q-wave infarction unless identified 6 or more months before the Screening Visit
- QT interval corrected for heart rate (QTc) \> 470 msec. If the QTc is prolonged in a patient with a pacemaker, the patient may be enrolled in the study upon discussion with the study PI
- Congenital long QT syndromeQ
- History of surgical castration
- Prior treatment for prostate cancer with surgery or prostate directed radiotherapy
Where
- New Haven, Connecticut
- Lebanon, New Hampshire
- New York, New York
- Seattle, Washington
Collaborators
Pfizer
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Sep 14, 2026 · Source of record for eligibility and locations