AuthorisedTherapeutic exploratory (Phase II)Interventional

A Phase 2b, Randomized, Placebo-controlled, Double-blind, Dose-ranging Trial to Assess the Efficacy and Safety of Ontunisertib in Patients with Fibrostenosing Crohn’s Disease

Crohn's disease can cause long-term swelling that leads to thick scar tissue in the gut. This scarring can narrow the bowel, making it hard for food to pass and often leading to surgery. This study is testing an experimental medicine called ontunisertib to see if it can safely reduce this scarring. Participants will be placed into groups by chance. Some will receive ontunisertib capsules at different doses, while others will receive a dummy capsule (placebo) with no active medicine. Neither you nor the doctors will know which group you are in. Doctors will track your health for up to a year using camera tests (endoscopies), specialised bowel MRI scans, and regular health checks. The main goal is to see if the medicine widens the narrowed area enough for an endoscope camera to easily pass through by week 24.

At a glance

Status

Authorised

Phase

Therapeutic exploratory (Phase II)

Sponsor

Agomab Spain S.L.U.

Enrolment target

160

Start

21 Sep 2026

Fibrostenosing Crohn’s Disease

What is this study about?

Crohn's disease is a condition that causes ongoing inflammation in the digestive system. Over time, repeated inflammation can leave behind thick, stiff scar tissue. When this happens in the bowel, it is called a stricture. These strictures narrow the intestine, which can cause severe stomach pain, bloating, sickness, and serious blockages. Current treatments mainly target inflammation, but they often cannot reverse tough scar tissue, leaving many people facing surgery.

Ontunisertib is a new, experimental tablet designed specifically to help tackle this scarring. Instead of just calming the immune system, it aims to target the biological processes that build scar tissue in the gut wall. Researchers hope this will soften or shrink the narrowing and help prevent blockages.

This Phase 2b trial is designed to see how well ontunisertib works and what dose is best. Researchers will measure success primarily by checking whether a small camera (an endoscope) can smoothly pass through the narrowed part of the bowel after 24 weeks and 52 weeks of treatment. They will also look at whether the treatment improves everyday symptoms and reduces the need for bowel surgery.

Key takeaways

Testing a new capsule called ontunisertib designed to reduce scar tissue in Crohn's disease.
Aims to widen narrowed sections of the small bowel to avoid the need for surgery.
Involves taking daily capsules and attending clinic visits over approximately 52 weeks.
Participants are randomly assigned to receive either ontunisertib or a dummy pill (placebo).
Participation is entirely voluntary and you can leave at any point without losing your standard care.

Who may be eligible?

This trial is open to adults aged 18 and older who have Crohn's disease with a known narrowing (stricture) in the ileum, which is the last part of the small bowel. Both men and women can take part.

To see if this trial is right for you, the medical team will carry out detailed checks. These will include a camera test (endoscopy) and a bowel MRI scan to confirm the exact size and nature of the narrowing. They will also run routine blood and urine tests to make sure your liver, kidneys, and heart are healthy enough for the study.

You might not be able to join if your bowel is completely blocked and needs immediate emergency surgery, if you have other serious bowel conditions, or if you have an active severe infection. The study doctor will review all your current treatments to make sure they do not clash with the study medication.

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.

I am aged 18 or older.
I have been diagnosed with Crohn's disease.
I have been told I have a narrowed section (stricture) in my small bowel.
I am able and willing to attend regular hospital appointments for tests and scans.
I am not in need of immediate, emergency bowel surgery.

Answer every question to see your result.

What does participation involve?

If you decide to take part, your participation will last for about one year (52 weeks), plus some time for initial screening and follow-up checks. You will be asked to take capsules by mouth every day. Because this is a double-blind trial, you will have an equal chance of receiving ontunisertib or a placebo (a dummy pill).

You will need to attend regular hospital visits so the research team can monitor your progress. These visits will involve blood and urine tests, physical check-ups, and heart tracings (ECGs). You will also have imaging scans of your bowel (MRE scans) and camera tests (endoscopies) at the start, at week 24, and at week 52 to look directly at the narrowing. You will also be asked to complete simple surveys about your symptoms and daily quality of life.

Potential risks and benefits

Taking part may help improve your Crohn's symptoms and widen the narrowed part of your bowel, but this cannot be guaranteed. You will also receive very close, expert medical monitoring throughout the trial. However, there are risks, including potential side effects from the study drug that are not yet fully known, as well as temporary discomfort from tests like endoscopies and MRI scans. There is also a chance you might receive the placebo instead of the active medicine. Joining is completely voluntary, and you are free to leave the trial at any time without it affecting your regular NHS care.

Locations (10)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

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Unverified
France
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Unverified
Germany
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Unverified
Poland
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Unverified
Spain
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Unverified
Czechia
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Unverified
Denmark
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Unverified
Austria
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Unverified
Italy
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Unverified
Belgium
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Unverified
Netherlands

Common questions

What is a placebo and why is it used?

A placebo looks just like the real medicine but contains no active ingredients. It is used as a comparison tool so researchers can prove whether any improvements or side effects are truly caused by the study drug.

Can I choose to get the real medicine instead of the placebo?

No. A computer randomly chooses who receives ontunisertib and who receives the placebo. Neither you nor your study doctor can choose your group, and neither will know which you are taking during the study.

Will I have to stop taking my regular Crohn's medications?

Some standard medicines may be allowed to continue at stable doses, while others might need to be paused. The study team will review your current prescriptions in detail to ensure your safety.

Does it cost anything to take part?

No, all study medications, tests, and doctor visits are provided free of charge. Most trials also offer help with travel expenses to and from the hospital.

What happens if my symptoms get worse during the study?

Your safety is always the top priority. If your bowel becomes more blocked or your health worsens, the medical team will step in immediately to provide standard medical treatment, which may include stopping the trial medicine.