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Study of Teverelix in Men After First Episode of Acute Urinary Retention to Assess Prostate Size and Urinary Function

Verified siteInvestigationalNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

The study focuses on men who have experienced a first episode of Acute Urinary Retention, a sudden inability to urinate that often occurs in the context of an enlarged prostate, known as Benign Prostatic Hyperplasia. The investigational medication being tested is called Teverelix DP, which belongs to a class of drugs known as a GnRH antagonist. This medication is given by injection and is intended to reduce the size of the prostate gland, thereby improving the flow of urine.

The purpose of the trial is to compare the effect of prostate volume reduction with that of a placebo over a 12‑week period, while also observing longer‑term outcomes up to one year. Participants will receive a series of study visits during which simple measurements such as the amount of urine left in the bladder after voiding (post-void residual volume) and the speed of urine flow (maximum urinary flow rate) are taken, along with questionnaires about urinary symptoms. The overall design involves random assignment to either the active medication or placebo, with both the participants and investigators unaware of the assignment, and follow‑up visits scheduled throughout the study to monitor safety and any changes in urinary function.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Enrollment and Randomization

    You will be asked to sign the consent form and will then be randomly assigned to receive either the study medication or a matching placebo.

    The random assignment determines whether you receive teverelix (the active drug) or a placebo, and you will not know which one you receive.

  2. Step 2

    Baseline Assessments

    Before any medication is given, you will undergo measurements of prostate size and tests of urinary function, including the amount of urine left in the bladder after voiding (post‑void residual volume, PVR) and the speed of urine flow (maximum urinary flow rate, Qmax).

    These measurements provide a reference point for later comparisons.

  3. Step 3

    First Dose of Study Medication

    If you are assigned to the active group, you will receive a single parenteral (injection) dose of teverelix.

    The injection may be a 90 mg powder for injection or a 120 mg solution for injection, depending on the formulation prepared for the study.

    The medication is given by a qualified health professional under sterile conditions.

  4. Step 4

    Early Follow‑Up Visits (Weeks 4 and 8)

    You will attend clinic visits at approximately week 4 and week 8 after the first injection.

    During each visit, the study team will repeat the prostate volume measurement and the urinary function tests (PVR and Qmax) to monitor early changes.

    Any side effects or safety concerns will be recorded at each visit.

  5. Step 5

    Primary Efficacy Evaluation (Week 12)

    At week 12, a comprehensive assessment of prostate size will be performed.

    The primary goal is to determine the percent change in total prostate volume compared with the baseline measurement.

    Urinary function tests will also be repeated to assess any improvement.

  6. Step 6

    Continued Treatment Period (Weeks 13–28)

    You will continue to receive the study medication according to the schedule defined by the protocol, which may include additional injections as directed by the study team.

    Clinic visits will be scheduled periodically up to week 28 to repeat prostate volume measurements and urinary function tests.

    During this 28‑week treatment period, the study will track the occurrence of any repeat episodes of acute urinary retention (AUR), the need for prostate‑related surgery, and any instances where PVR exceeds 300 mL together with Qmax below 10 mL/sec.

  7. Step 7

    Observation Phase (Weeks 29–52)

    After the treatment period ends at week 28, you will enter a 52‑week observation phase.

    During this time, you will attend scheduled visits to monitor long‑term outcomes, including prostate size, urinary function, and safety parameters.

    The study will assess whether you experience any further episodes of AUR, require surgery, or develop the defined urinary function thresholds (PVR >300 mL with Qmax <10 mL/sec, or PVR >60 % of total bladder volume).

Who can join the trial?

8 criteria

  • Be a man who is at least 45 years old.
  • Provide a signed written agreement to take part in the study.
  • Have a successful Trial Without Catheter (TWOC), meaning you were able to urinate on your own after the catheter was removed, did not need another catheter, and your bladder retained no more than 200 mL of urine after the test (called post‑void residual volume).
  • Have experienced the first episode of a sudden inability to urinate (acute urinary retention) within the 6 days before the screening visit.
  • Have a prostate that weighs more than 40 grams, as measured by an ultrasound performed through the rectum (TRUS).
  • Be able to start or keep using an alpha‑blocker medicine (a drug that helps relax the muscles in the prostate and bladder) before randomisation, and continue the same medicine and dose during the study if possible.
  • Agree to use reliable birth‑control methods for the whole 1‑year treatment period and for 3 months after the last dose, such as using a condom together with a method used by the female partner, or to remain completely sexually abstinent if that matches your normal lifestyle. Methods like periodic abstinence or withdrawal are not allowed.
  • Never have taken medicines called GnRH analogues before (these are drugs that affect hormone levels and are sometimes used for prostate conditions).

Who cannot join the trial?

20 criteria

  • You have taken part in another research study that used an experimental drug within the past 3 months.
  • You are currently using, or have used in the last 3 months, any of the following: another investigational drug, herbal products that can lower male hormones (such as red reishi, licorice, white peony, green tea, spearmint, black cohosh, chaste tree, saw palmetto), anti‑androgen medicines, testosterone replacement therapy, medications that block the enzyme 5α‑reductase (for example dutasteride or finasteride), the drug bethanechol chloride, or any other medicine or herb that could change hormone levels (such as St. John’s wort).
  • You have had an episode of acute urinary retention caused by major abdominal, pelvic, or spinal surgery.
  • You have had an episode of acute urinary retention caused by a neurological problem.
  • You cannot safely take alpha blockers (medicines that relax the muscles in the prostate and bladder neck).
  • You have had any previous surgery on the prostate or the urethra.
  • You have ever been diagnosed with prostate cancer, either by tissue testing (histology) or by clinical evaluation.
  • You have any other medical condition that is not stable.
  • Your laboratory tests show any of the following: liver enzymes (AST/SGOT or ALT/SGPT) more than twice the normal range, total bilirubin more than 1.5 times the normal range, or an estimated kidney function (eGFR) below 30 mL/min.
  • You have a congenital long QT syndrome or an abnormal heart tracing (ECG) such as a recent heart attack (Q‑wave infarction less than 6 months old) or a corrected QT interval (QTcF) longer than 480 milliseconds.
  • You are allergic to mannitol, or you have severe dehydration, no urine output (anuria), severe heart failure, fluid buildup in the lungs, or very high blood sugar concentration (hyperosmolarity).
  • You have a history of alcohol or drug abuse within the past 12 months.
  • You have any serious, unstable, or uncontrolled medical problem that the doctor believes could increase your risk of organ problems or make participation unsafe.
  • Your blood level of Prostate Specific Antigen (PSA) is higher than 20 ng/mL.
  • You need a suprapubic catheter (a tube placed through the abdomen into the bladder) because a regular urethral catheter could not be placed.
  • You have or are suspected to have a neurogenic bladder (bladder problems caused by nerve damage).
  • You have an isolated problem with the bladder neck (the opening that connects the bladder to the urethra).
  • You have an active infection or inflammation of the prostate (prostatitis), either acute or chronic.
  • You have a confirmed or suspected urethral stricture (narrowing of the urethra).
  • You have known bladder stones.
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Investigated drugs

  • Teverelix

    is an experimental medicine that blocks a hormone called GnRH. By blocking this hormone, the drug can help shrink the prostate gland and improve the flow of urine in men who have had a sudden blockage of urine (acute urinary retention). In this study, Teverelix is supplied as a powder that must be mixed with liquid before it is injected into the body. The researchers are giving this medication to participants to see how well it reduces prostate size and helps urinary function over 12 weeks.

  • Teverelix TFA

    is the same experimental GnRH‑blocking medicine, but it is provided as a ready‑to‑use liquid solution for injection. Like the powder form, it is intended to shrink the prostate and improve urine flow after an episode of acute urinary retention. In the trial, participants receive this liquid version to compare its effects with the powder form and to determine how effectively it works in reducing prostate volume and improving urinary symptoms.

What is already known about the treatment

  • Teverelix

    Teverelix is supplied as a sterile powder that is mixed with liquid and given by injection under the skin or into a vein. It is currently an investigational drug being studied in clinical trials for men who have had a first episode of sudden inability to urinate. The medicine works by blocking a hormone signal that tells the body to make testosterone, which helps reduce the size of the prostate and improve urine flow. It belongs to the class of GnRH antagonists, a type of hormonal therapy.

  • Teverelix TFA

    Teverelix TFA is a ready‑to‑use liquid that is injected directly into a vein or muscle. It is also in the investigational stage, being tested for its effect on prostate size and urinary problems after an acute urinary retention episode. The drug blocks the GnRH hormone receptor, lowering testosterone levels and helping the prostate shrink, which can ease urination. It is classified as a GnRH antagonist, a hormonal agent used to manage prostate‑related conditions.

Investigated diseases

Acute urinary retention - Acute urinary retention is a sudden inability to empty the bladder. It often starts with a strong urge to urinate followed by a weak stream or no stream at all. Urine builds up, causing the bladder to become distended. If the blockage is not relieved, the bladder wall stretches and may lose its ability to contract properly. Recurrent episodes can occur when the underlying cause remains untreated.
Trial detailsLast updated 5 Nov 2026
Age18+ yearsPhasePhase IITrial ID2026-525963-41-00Protocol codeANT-2111-02Estimated enrolment97 patientsSponsorAntev Limited

sourced from the EU Clinical Trials Register and site verification

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