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A study to evaluate the efficacy and safety of etrasimod arginine in children with moderately to severely active ulcerative colitis

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What is this trial about?

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

This study investigates the effectiveness and safety of etrasimod arginine, also referred to by the code PF-07915503, in children. The focus is on treating Ulcerative Colitis, which is a type of long-term inflammation in the digestive tract that causes swelling and sores in the lining of the large intestine. The research specifically looks at children with moderate to severe versions of this disease.

The purpose of the study is to see if etrasimod can help children reach clinical remission, a state where the symptoms of the disease are significantly reduced or disappear. During the study, participants will receive the medication in the form of tablets or granules taken by mouth. Over a period of 52 weeks, the way the body processes the medicine and any side effects will be monitored. Medical professionals will also check for changes in growth and physical development to ensure the treatment is safe for younger patients.

The research process

The trial runs in 3 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Start of treatment

    The treatment begins with the administration of etrasimod arginine. this medicine is taken by mouth in the form of either granules or tablets.

    For the tablet form, the dose is 2 mg.

  2. Step 2

    Treatment monitoring

    During the first 12 weeks of the study, clinical progress is assessed using the modified mayo score (mms), which is a tool used to measure the activity of ulcerative colitis (an inflammatory disease of the large intestine).

    The assessment includes checking for clinical response, endoscopic improvement (looking at the inside of the intestine), and symptomatic remission (the disappearance of symptoms).

    The pediatric ulcerative colitis activity index (pucai) is also used to check for clinical remission or response.

  3. Step 3

    Long-term evaluation

    The treatment continues for a total of 52 weeks.

    At the 52-week mark, the primary goal is to determine if clinical remission has been achieved based on the modified mayo score (mms).

    Throughout the study, blood levels of etrasimod are measured, and safety is monitored by tracking adverse events (unwanted side effects) and laboratory abnormalities (changes in blood or urine test results).

    Physical development is monitored by measuring changes in height, weight, and tanner stage (a scale used to measure physical development during puberty).

Who can join the trial?

7 criteria

  • You must be at least 2 years old but younger than 12 years old at the start of the study.
  • You must have been diagnosed with ulcerative colitis (an inflammatory disease of the large intestine) at least 4 weeks before joining the study.
  • The diagnosis must have been confirmed through histology (examining tissue samples under a microscope) and endoscopy (using a tiny camera to look inside the body).
  • The disease must affect areas of the intestine that extend past the rectum (the very end of the large intestine).
  • The disease must be moderately to severely active, meaning it shows significant symptoms and inflammation.
  • The disease activity must meet specific scores on medical scales, including an Endoscopic Score (a measurement of how much inflammation is seen through a camera) and a Red Blood subscore (a measurement of bleeding in the intestine).
  • You must have previously used at least one conventional therapy (standard medicines) or biologic/JAK inhibitor (specialized drugs that target specific parts of the immune system) and found that they either did not work well enough, stopped working, or caused side effects that you could not tolerate.

Who cannot join the trial?

13 criteria

  • You cannot participate if you have any form of inflammatory bowel disease (a group of conditions that cause swelling and irritation in your digestive tract) other than ulcerative colitis.
  • You cannot join if you have already used more than two advanced treatments, which are specific types of strong medicines called biologics or JAK inhibitors used to control swelling.
  • You are not eligible if you currently have very severe and widespread ulcerative colitis, or if you recently had a sudden worsening of your condition that required hospitalization with intravenous corticosteroids (strong medicines given directly into a vein to reduce swelling).
  • You cannot participate if you have a history of bowel perforation (a hole in the wall of the intestine) or a colectomy (the surgical removal of part or all of the large intestine).
  • You are excluded if you recently had toxic megacolon (a dangerous condition where the colon becomes very swollen and enlarged).
  • You must have healthy blood, liver, and kidney function, meaning your body's organs are working properly.
  • You cannot participate if you have retinopathy (damage to the retina at the back of the eye) or macular edema (swelling in the part of the eye responsible for central vision).
  • If you have diabetes mellitus (a condition involving high blood sugar), it must be well-controlled with an HbA1c level (a measure of average blood sugar over several months) of less than 9%.
  • You cannot join if you have a primary or secondary immunodeficiency (a condition where your body's immune system cannot protect you from infections), a history of cancer, lymphoproliferative disorders (disorders involving the growth of white blood cells), or opportunistic infections (infections that happen more often in people with weakened immune systems).
  • You are not eligible if you have had recent severe infections or any chronic infections, such as tuberculosis, viral hepatitis, or human immunodeficiency virus (HIV).
  • You cannot participate if there are signs of pulmonary obstruction (a blockage in the lungs or airways).
  • You are excluded if you have congenital heart disease (heart problems present from birth), heart failure, arrhythmias (irregular heartbeats), symptomatic bradycardia (a dangerously slow heart rate that causes symptoms), syncope (fainting), or atrioventricular (AV) block (a problem with the electrical signals in the heart).
  • You cannot enroll if you have infectious colitis (inflammation of the colon caused by an infection), a parasitic infection, or a positive test for Clostridioides difficile (C. diff) toxin (a type of bacteria that causes severe diarrhea).
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Investigated drugs

Etrasimod is an oral medication being studied to help treat children with moderate to severe ulcerative colitis, a condition that causes inflammation in the digestive tract. This study aims to see how well the medicine works to bring the disease into remission and to ensure it is safe for young patients to use.

What is already known about the treatment

Etrasimod arginine - This medication is taken orally in the form of granules or tablets and is currently being studied in clinical trials for its effectiveness. It is primarily used to treat moderately to severely active ulcerative colitis, a condition that causes inflammation in the digestive tract. As an immune system modulator, it works by attaching to specific receptors on white blood cells to prevent them from moving into the gut and causing inflammation.

Investigated diseases

Ulcerative Colitis - This is a condition that causes inflammation and sores in the lining of the large intestine and rectum. It typically involves continuous inflammation that starts in the rectum and spreads upward into the colon. Over time, the inflammation can lead to redness, swelling, and ulcers on the inner surface of the intestinal wall. The disease often progresses through periods of active inflammation followed by periods of relative calm. Symptoms may vary in intensity as the inflammation affects different parts of the large intestine.
Trial detailsLast updated 2 Oct 2026
Age0-17PhasePhase IITrial ID2025-523100-77-00Protocol codeC5041018Estimated enrolment24 patientsSponsorPfizer Inc.

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

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