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One-Year Effectiveness Study of Guselkumab in Adults with Crohn’s Disease

Verified siteInvestigationalNo placebo
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What is this trial about?

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

Crohn's disease is a long‑lasting condition that causes inflammation of the digestive tract, leading to stomach pain, diarrhea, weight loss, and fatigue. The study uses the medicine guselkumab, which is given as a small injection under the skin with a pre‑filled syringe. This drug works by targeting parts of the immune system that cause the gut inflammation, with the aim of keeping the disease quiet and improving daily life.

The purpose of the study is to evaluate the one‑year effectiveness of guselkumab in real‑world patients with Crohn's disease. Participants receive regular injections of the medication for up to twelve months and attend clinic visits at about 12, 24 and 48 weeks. During these visits doctors check how the patient feels, review stool tests that measure a protein called fecal calprotectin (a sign of gut inflammation), and look at the intestines using one of three imaging methods: an endoscopy (a thin camera inserted to see inside the gut), an MRI (a scan that uses magnets to create pictures of the body), or IUS (an ultrasound performed on the skin). Questions about quality of life are also completed to see if the treatment helps patients feel better overall.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Enrollment confirmation

    After joining the study, sign the consent form and receive a study identification number.

    The study staff will verify eligibility based on the diagnosis of crohn's disease.

  2. Step 2

    Baseline visit and first injection

    Attend the first study visit, where a healthcare professional will administer guselkumab as a 400 mg subcutaneous injection using a pre‑filled syringe.

    Receive instructions on the injection schedule and on how to record symptoms and any side effects.

  3. Step 3

    Week 12 (month 3) visit

    Return to the clinic at week 12 for the second dose of guselkumab (400 mg subcutaneous injection).

    Provide a stool sample so the laboratory can measure fecal calprotectin, a marker of inflammation.

    Undergo clinical assessment, which may include endoscopy, mri, or ius (ultrasound) to evaluate the intestine.

    Complete the short ibd‑q questionnaire that measures quality of life.

  4. Step 4

    Week 24 (month 6) visit

    Receive the third dose of guselkumab (400 mg subcutaneous injection) at the clinic.

    Again provide a stool sample for fecal calprotectin testing.

    Repeat the clinical assessment (endoscopy, mri, or ius) and the short ibd‑q questionnaire.

    The study team will record any changes in disease activity or medication use.

  5. Step 5

    Week 48 (month 12) final visit

    Receive the fourth and final dose of guselkumab (400 mg subcutaneous injection) during the last scheduled visit.

    Provide a final stool sample for fecal calprotectin measurement.

    Undergo the final clinical assessment, which may include endoscopy, mri, or ius, and complete the short ibd‑q questionnaire.

    The study will evaluate whether steroid‑free clinical remission and other study endpoints have been achieved.

  6. Step 6

    Ongoing symptom reporting

    Throughout the 48‑week period, record any new or worsening symptoms, side effects, or medication changes in the study diary.

    Report the information to the study staff according to the instructions given at the baseline visit.

Who can join the trial?

7 criteria

  • You must have a confirmed diagnosis of Crohn's disease that follows the standard guidelines used by experts.
  • You must not have any medical reason (a contraindication) that would prevent you from safely taking the study drug guselkumab.
  • Your disease must be currently active, which means you have either abdominal pain rated higher than 1 or you have more than 3 bowel movements a day, and a lab test called fecal calprotectin must be greater than 250 µg/g. (Fecal calprotectin is a protein measured in stool that signals inflammation in the intestines.)
  • Your doctor must have shown recent evidence of active disease (within the last 2 months) using one of these imaging tests: endoscopy (a camera placed in the gut), MRI (magnetic resonance imaging), or IUS (intestinal ultrasound).
  • You must be 18 years of age or older when you sign the consent form.
  • You cannot be taking part in any other experimental treatment studies at the same time.
  • You may have never used strong, advanced medicines for Crohn's disease, or you may have used one or more of them in the past.

Who cannot join the trial?

6 criteria

  • Having taken a medicine that blocks the immune protein IL‑23 (called an anti‑IL23 drug) before.
  • Using a strong ( advanced therapy ) together with the study drug guselkumab.
  • Having an ostomy (a surgical opening that allows waste to leave the body).
  • Being pregnant or breastfeeding.
  • Having Crohn’s disease that mainly affects the area around the anus (perianal disease).
  • Being under legal protection (for example, having a court‑appointed guardian).
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Investigated drugs

Guselkumab is a medication that is given as an injection under the skin. It works by targeting a specific part of the immune system that can cause inflammation in the intestines. In this study, patients with Crohn’s disease receive guselkumab to see how well it can control their symptoms and keep the disease under control over one year in everyday medical practice.

What is already known about the treatment

Guselkumab - Guselkumab is administered by subcutaneous injection using a pre‑filled syringe that delivers a solution of 100 mg/mL. It is an approved biologic drug that is well documented in medical literature and widely used in clinical practice. The main use is for treating Crohn’s disease and other inflammatory conditions such as plaque psoriasis. Guselkumab is a monoclonal antibody that binds to the p19 subunit of interleukin‑23, blocking this signaling molecule and thereby reducing inflammation.

Investigated diseases

Crohn's disease - Crohn's disease is a long‑lasting condition that causes inflammation in the digestive tract, which can appear anywhere from the mouth to the anus. It often begins with mild abdominal discomfort and loose stools, and the inflammation may spread deeper into the intestinal wall. Over time, the affected areas can become thickened, leading to narrowing (strictures) that make passing food difficult. Some people develop abnormal passages (fistulas) that connect the intestine to other organs or the skin. The pattern of flare‑ups and quieter periods can vary widely among individuals.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2025-524573-16-00Protocol codeGETAID 2025-03Estimated enrolment210 patientsSponsorGroupe D'etude Therapeutique Des Affections Inflammatoires Du Tube Digestif

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