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Long-Term Safety Study of Obefazimod for Patients with Moderate to Severe Ulcerative Colitis

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What is this trial about?

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

This clinical trial is focused on studying the effects of a medication called ABX464 in patients with moderate to severe ulcerative colitis. Ulcerative colitis is a chronic condition that causes inflammation and sores in the lining of the large intestine, leading to symptoms like abdominal pain and diarrhea. The medication being tested, ABX464, is taken as a hard capsule once daily at a dose of 25 milligrams.

The purpose of this study is to evaluate the long-term safety of ABX464 in individuals who have previously participated in related studies. Participants will continue taking the medication over an extended period, and their health will be monitored to assess any side effects and the overall effectiveness of the treatment. The study aims to gather information on how well patients respond to the medication over time, including any improvements in their symptoms and overall health.

Throughout the study, participants will have regular check-ups to monitor their condition and any changes in their health. This includes looking at specific markers in the blood and stool that indicate inflammation, as well as using imaging techniques to assess the heart's function. The study will also track any adverse events or side effects experienced by participants to ensure the medication's safety. The information collected will help determine the potential benefits and risks of using ABX464 for treating moderate to severe ulcerative colitis.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Participation begins after completing previous studies ABX464-102 or ABX464-104.

    Eligibility requires endoscopic improvement with a rectal bleeding sub-score of 0 at the end of the previous study.

    Participants must agree to comply with study visits and procedures.

  2. Step 2

    Medication administration

    The medication ABX464 is administered as a hard capsule.

    The dosage is 25 mg taken once daily.

    The route of administration is oral.

  3. Step 3

    Safety and efficacy evaluation

    The primary objective is to evaluate the long-term safety of ABX464.

    The number of adverse events in participants is monitored.

    Secondary objectives include assessing clinical and endoscopic remission and response at yearly visits.

  4. Step 4

    Monitoring and assessments

    Regular assessments include changes in CRP and fecal calprotectin levels.

    Echocardiography is used to monitor heart function, including left ventricular ejection fraction and global longitudinal strain.

    Participants undergo laboratory tests to identify any clinically significant abnormalities.

  5. Step 5

    Duration of the study

    The study is estimated to conclude by March 31, 2026.

    Participants are required to use effective contraception during the study and for at least 21 days after its completion.

Who can join the trial?

6 criteria

  • Participants must have previously completed the ABX464-102 or ABX464-104 clinical studies.
  • Participants should show improvement in their condition, with no rectal bleeding, at the end of the previous study. This improvement is checked using a test called the Mayo endoscopic sub score, which should be 1 or less.
  • Participants must be able and willing to attend study visits and follow the study procedures.
  • Participants need to understand, sign, and date a written consent form before starting any study-related activities. This form shows they agree to take part in the study.
  • Women who can have children and men receiving the study treatment, along with their partners, must agree to use a very effective method of birth control during the study and for at least 21 days after the study ends. Women must either be unable to have children due to surgery or use a very effective birth control method. Women will join the study after confirming their menstrual period and a negative pregnancy test. They must also agree to take a monthly urine pregnancy test. Effective birth control methods include not having sex, using an intrauterine device (IUD), or taking hormonal birth control that stops ovulation. Men must use condoms during the study and for at least 21 days after it ends. Men should not donate sperm while using birth control. A woman is considered able to have children from her first period until menopause unless she has had surgery to prevent pregnancy. Menopause is when a woman has not had a period for 12 months without another medical reason. A man is considered able to have children after puberty unless he has had surgery to prevent it.
  • Participants should be part of a social security system (only for sites in France).

Who cannot join the trial?

5 criteria

  • Patients who do not have Moderate to Severe Ulcerative Colitis cannot participate. This is a condition where the colon and rectum become inflamed, causing symptoms like diarrhea and abdominal pain.
  • Patients who are not within the specified age range cannot participate. The study is for certain age groups, but the exact ages are not specified here.
  • Patients who are not part of the specified clinical trial groups cannot participate. This means the study is looking for specific types of participants, but the details are not provided here.
  • Both male and female patients can participate, so exclusion is not based on gender.
  • Patients who are considered part of a vulnerable population may not be eligible. Vulnerable populations can include groups like children, pregnant women, or those with certain disabilities, but specific details are not provided here.
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Investigated drugs

ABX464 is a medication being studied for its long-term safety and effectiveness in treating people with moderate to severe active ulcerative colitis. Ulcerative colitis is a condition that causes inflammation and sores in the digestive tract. This medication is taken once daily and aims to help manage the symptoms and improve the quality of life for those affected by this condition.

What is already known about the treatment

ABX464 – ABX464 is administered orally in the form of a tablet, taken once daily. It is currently being studied in clinical trials, specifically in a Phase II open-label study, to assess its long-term safety and effectiveness for treating moderate to severe ulcerative colitis. The medication is primarily indicated for individuals with active ulcerative colitis, a chronic inflammatory bowel disease. At the molecular level, ABX464 works by modulating the immune response, potentially reducing inflammation in the colon. It is classified pharmacologically as an anti-inflammatory agent.

Investigated diseases

Ulcerative Colitis – Ulcerative colitis is a chronic inflammatory condition affecting the colon and rectum. It is characterized by continuous inflammation of the innermost lining of the large intestine, leading to ulcers and sores. Symptoms often include abdominal pain, diarrhea, and rectal bleeding. The disease typically progresses with periods of flare-ups and remissions. Over time, the inflammation can lead to complications such as colon narrowing or increased risk of colon cancer. The exact cause is unknown, but it is believed to involve an abnormal immune response in genetically predisposed individuals.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-507974-42-00Protocol codeABX464-108Estimated enrolment203 patientsSponsorAbivax

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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.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).