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AuthorisedTherapeutic confirmatory (Phase III)Interventional

A Phase 3b, Open-Label Study of Crinecerfont to Evaluate Androgen Reduction and Related Outcomes in Adults With Classic Congenital Adrenal Hyperplasia

This study is testing a new medicine called crinecerfont (also known as NBI-74788) in adults who have classic congenital adrenal hyperplasia (CAH). CAH is a genetic condition affecting the adrenal glands, which sit near the kidneys. People with CAH usually produce too little cortisol and too much male hormone (androgen). Currently, people often take daily steroid tablets to control hormone levels, but high doses of steroids can lead to unwanted long-term side effects like weight gain, weak bones, and high blood pressure. In this open-label study, every participant receives crinecerfont. Researchers want to find out if taking it for 24 weeks can successfully lower androgen levels in the blood before patients take their usual steroid dose. The main goal is to see if the medicine works well and is safe for adults living with this condition.

At a glance

Status
Authorised
Phase
Therapeutic confirmatory (Phase III)
Sponsor
Neurocrine Biosciences Inc.
Enrolment target
75
Start
23 Jul 2026

What is this study about?

Classic congenital adrenal hyperplasia, or CAH, is a lifelong condition you are born with. In people with CAH, the adrenal glands cannot make enough of an essential hormone called cortisol. To try to fix this, the body triggers chemical signals that cause the adrenal glands to overwork. As a result, the body ends up making far too many androgens, which are male sex hormones.

At present, the standard treatment is taking steroid medicines, known as glucocorticoids. While these tablets replace the missing cortisol and help bring down androgen levels, people often have to take very high doses to keep the male hormones in check. Over many years, taking large amounts of steroids can cause significant health problems, such as brittle bones, weight gain, sleep issues, and an increased risk of heart disease.

This clinical trial is testing a new tablet called crinecerfont. It works by blocking the signals that tell the adrenal glands to make too many androgens. Because this is an 'open-label' study, all participants will receive the study medicine rather than a dummy pill (placebo).

If crinecerfont is shown to effectively reduce androgen levels over 24 weeks, it could provide doctors with a brand new way to help manage CAH. In the future, this could allow people with the condition to keep their hormones balanced while safely lowering their daily steroid doses.

Key takeaways

  • The study tests a new medicine called crinecerfont for adults with classic CAH.
  • The trial aims to lower high male hormone (androgen) levels over 24 weeks.
  • This is an open-label study, so every person who joins receives the active medicine.
  • The goal is to find better ways to treat CAH without relying on very high steroid doses.
  • Participation is entirely voluntary, and you can stop at any time.

Who may be eligible?

This study is looking for adults aged 18 and older who have been diagnosed with classic congenital adrenal hyperplasia (CAH). Both men and women can take part.

To join, participants will usually need to be taking standard steroid treatment for their CAH and be willing to attend regular hospital or clinic visits. Because the study measures hormone levels in your blood, you will need to be comfortable having routine blood tests.

You may not be able to join if you have certain other serious medical conditions, such as severe liver or kidney problems, or if you are taking specific medications that could interfere with the study drug. The study team will review your full medical history with you to ensure taking part is safe.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

  1. I am aged 18 or older.
  2. I have a confirmed diagnosis of classic congenital adrenal hyperplasia (CAH).
  3. I am currently taking steroid replacement therapy for my condition.
  4. I am willing and able to attend clinic appointments for at least 24 weeks.
  5. I am comfortable having routine blood tests to check my hormone levels.
Answer every question to see your result.

What does participation involve?

Taking part involves visiting a specialist study clinic regularly over at least 24 weeks (around six months). During your visits, the research team will check your overall health, measure your blood pressure, and perform routine blood tests to check your hormone levels. You will take the study medicine, crinecerfont, alongside your usual care. The team will ask you to report how you feel and note any side effects you might experience. Travel expenses to attend appointments are often covered, and the medical team will support you throughout the trial.

Potential risks and benefits

Taking part may help lower your androgen levels, and you will receive close medical monitoring from hormone specialists throughout the trial. Your participation will also help researchers learn more about new treatments for CAH. However, there is no guarantee you will personally benefit. As crinecerfont is an experimental drug, there is a risk of side effects, which the study doctor will explain in detail before you start. Routine procedures like blood tests may also cause minor bruising. You are completely free to leave the trial at any time, and doing so will not affect your usual NHS care.

Locations (9)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.
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    Unverified
    Czechia
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    Unverified
    Germany
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    Unverified
    Sweden
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    Unverified
    Portugal
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    Unverified
    Romania
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    Unverified
    Bulgaria
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    Unverified
    Italy
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    Unverified
    Austria
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    Unverified
    Spain

Common questions

What is an open-label study?

An open-label study means that both you and your study doctor know you are receiving the real study medicine. There is no dummy pill (placebo) used in this trial.

Do I have to stop taking my usual CAH medication?

No, you will not be asked to suddenly stop your essential steroids. Any changes to your medication are carefully planned and monitored by the study doctor.

How long will I be in the trial?

The main part of the study tracks your progress over 24 weeks (about six months), though there may be a short screening period before and follow-up checks afterwards.

Does taking part cost anything?

No. The study medication and all trial-related tests are provided free of charge, and help with travel costs is usually available.

What happens if I change my mind?

You can leave the study at any point without giving a reason. Your standard medical care will continue as normal.

How to find out more

Always speak to your GP or specialist before deciding to take part in a study.

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