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Study on GS-1427 for Adults with Moderate to Severe Ulcerative Colitis

Fast replyInvestigationalNo placebo
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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 a condition called Ulcerative Colitis, which is a type of inflammatory bowel disease that causes long-lasting inflammation and ulcers in the digestive tract. The study is testing a new treatment called GS-1427, which is taken as a film-coated tablet. The purpose of the study is to evaluate how effective and safe GS-1427 is for adults with moderately to severely active Ulcerative Colitis.

Participants in the study will be randomly assigned to receive either the GS-1427 tablets or a placebo. The study will last for up to 52 weeks, with the main focus on the results at Week 12. During this time, participants will take the medication orally, and their health will be monitored closely to see how well the treatment works and to check for any side effects. The study aims to see if the treatment can help reduce symptoms and improve the condition of the digestive tract.

Throughout the study, researchers will look for improvements in symptoms such as stool frequency and rectal bleeding, as well as overall healing of the digestive tract. The study will also track any adverse events or changes in laboratory tests to ensure the safety of the participants. The ultimate goal is to find out if GS-1427 can provide a new and effective treatment option for people living with 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

    Upon joining the study, participants are confirmed to have ulcerative colitis (UC) for at least 90 days. This is verified through previous endoscopy and histology records.

    Participants must have a minimum disease extent of 15 cm from the anal verge and a moderately to severely active UC as determined by endoscopy during screening.

  2. Step 2

    Randomization and treatment initiation

    Participants are randomly assigned to receive either the study medication GS-1427 or a placebo. The medication is administered orally in the form of film-coated tablets.

    The dosage and frequency of GS-1427 are determined by the study protocol, which aims to evaluate different doses for efficacy and safety.

  3. Step 3

    Treatment duration

    The treatment period lasts for 12 weeks. During this time, participants continue to take the assigned medication as per the study guidelines.

  4. Step 4

    Evaluation of clinical response

    At the end of 12 weeks, the primary goal is to assess the clinical response. This is defined as a significant decrease in the modified Mayo Clinic Score (mMCS) and improvement in rectal bleeding scores.

    Secondary evaluations include checking for any adverse events, clinical remission, and mucosal healing.

  5. Step 5

    Long-term follow-up

    Participants may be monitored for up to 52 weeks to assess long-term clinical remission and safety outcomes.

    The study aims to gather comprehensive data on the efficacy and safety of GS-1427 over an extended period.

Who can join the trial?

10 criteria

  • Participants must have been diagnosed with Ulcerative Colitis (UC) for at least 90 days before joining the study. This diagnosis should be confirmed by a procedure called endoscopy (a test that looks inside the colon) and histology (examining tissue samples under a microscope).
  • Participants must have UC affecting at least 15 centimeters of the colon, starting from the anal verge (the opening of the anus).
  • Participants must have moderately to severely active UC, which is determined by an endoscopy during the screening process. This is measured using a score called the modified Mayo Clinic Score (mMCS), which should be between 5 to 9 points, including an endoscopic subscore of at least 2.
  • Participants must have had an inadequate response, lost response, or been intolerant to at least one conventional UC treatment. These treatments include corticosteroids (a type of medication that reduces inflammation) and immunomodulators like azathioprine or 6-mercaptopurine.
  • Alternatively, participants must have had an inadequate response, lost response, or been intolerant to one or two advanced therapy mechanisms. These include:
    • Tumor necrosis factor-alpha inhibitors such as infliximab, adalimumab, golimumab, or their biosimilars.
    • Interleukin-12/23 inhibitors like ustekinumab.
    • Sphingosine 1-phosphate receptor modulators such as ozanimod.
    • Janus kinase inhibitors like tofacitinib, upadacitinib, or filgotinib.
    • Both male and female participants are eligible for the study.
    • The study includes participants from vulnerable populations.

Who cannot join the trial?

5 criteria

  • Patients who have a different condition than Ulcerative Colitis (UC) cannot participate. Ulcerative Colitis is a condition that causes inflammation and sores in the colon and rectum.
  • Patients who are not within the specified age range cannot participate. The age range for this study is not specified here, but it is important to be within the required age group.
  • Patients who are not part of the specified clinical trial group cannot participate. This means that only certain groups of people, based on specific criteria, are allowed in the study.
  • Both male and female patients can participate, but if a patient does not identify as either, they may not be eligible.
  • 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.
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Investigated drugs

GS-1427 is a medication being studied for its potential to help people with moderately to severely active ulcerative colitis. The trial aims to see how effective and safe this medication is in improving the symptoms of ulcerative colitis over a 12-week period. Participants in the study will receive this medication to evaluate its ability to provide a clinical response, which means reducing the symptoms and inflammation associated with the condition.

What is already known about the treatment

GS-1427 – This medication is administered orally and is currently being studied in clinical trials for its effectiveness in treating moderately to severely active ulcerative colitis. It is in the experimental phase, with ongoing research to determine its safety and efficacy. The main therapeutic indication for GS-1427 is ulcerative colitis, a chronic inflammatory condition of the colon. At the molecular level, GS-1427 works by modulating specific pathways involved in inflammation, aiming to reduce the symptoms and progression of the disease. 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 inflammation and ulceration of the innermost lining of the large intestine. 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 strictures or increased risk of colon cancer. The exact cause is unknown, but it is believed to involve an abnormal immune response in genetically susceptible individuals.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-508304-38-00Protocol codeGS-US-409-5704Estimated enrolment256 patientsSponsorGilead Sciences 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.

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).