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Study on the Effects of SAR443820 and Gadobutrol in Patients with Multiple Sclerosis

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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 new treatment for Multiple Sclerosis (MS), a disease that affects the brain and spinal cord, leading to symptoms like fatigue, difficulty walking, and vision problems. The treatment being tested is called SAR443820, which is taken as a film-coated tablet. The study will compare the effects of this treatment to a placebo, which looks like the treatment but does not contain the active substance. The main goal is to see how SAR443820 affects levels of a protein in the blood called serum neurofilament, which can be a marker of nerve damage in MS.

The study is divided into two parts. In the first part, participants will be randomly assigned to receive either SAR443820 or a placebo for a certain period. This part is "double-blind," meaning neither the participants nor the researchers will know who is receiving the actual treatment or the placebo. After this phase, all participants will have the opportunity to receive SAR443820 in an "open-label" extension, where everyone knows they are receiving the treatment. This will help researchers understand the long-term effects of the treatment.

Throughout the study, participants will undergo regular check-ups and tests, including MRI scans, to monitor changes in their condition and any side effects. The study aims to provide valuable information on whether SAR443820 can help reduce nerve damage in people with Multiple Sclerosis and improve their quality of life over time.

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

    Initial phase of the study

    Upon joining the study, the participant will be randomly assigned to receive either the medication SAR443820 or a placebo. This process is double-blind, meaning neither the participant nor the researchers know which treatment is being administered.

    The medication SAR443820 is provided in the form of a film-coated tablet and is taken orally. The specific dosage and frequency will be determined by the study protocol.

  2. Step 2

    Part A of the study

    This phase lasts for 48 weeks. During this time, the effect of SAR443820 on serum neurofilament levels will be assessed. Serum neurofilament levels are a marker used to evaluate nerve damage in multiple sclerosis.

    Participants will undergo regular assessments, including magnetic resonance imaging (MRI) to monitor brain lesions and other health evaluations to track any changes in disability status.

  3. Step 3

    Transition to part B

    After completing Part A, participants will enter Part B, which is an open-label extension. This means all participants will receive SAR443820 regardless of their initial group assignment.

    The focus of Part B is to observe long-term trends in serum neurofilament levels and other health indicators over an additional 48 weeks, making the total study duration 96 weeks.

  4. Step 4

    Monitoring and assessments

    Throughout the study, participants will have regular check-ups to monitor their health and any potential side effects. This includes blood tests, MRI scans, and assessments of physical abilities.

    Participants will be asked to report any adverse events or changes in their health status to the study team.

  5. Step 5

    Completion of the study

    At the end of the 96-week period, participants will undergo a final set of assessments to evaluate the overall impact of the treatment.

    The data collected will contribute to understanding the effectiveness and safety of SAR443820 in treating multiple sclerosis.

Who can join the trial?

6 criteria

  • Must be a male or female between 18 and 60 years old when signing the consent form.
  • Must have a diagnosis of **multiple sclerosis** (MS), which is a condition affecting the brain and spinal cord. This includes types like **relapsing-remitting MS (RRMS)**, **secondary progressive MS (SPMS)**, or **primary progressive MS**. SPMS is when the disease starts with relapses and then progresses with or without relapses.
  • Must have a score between 2 and 6 on the **Expanded Disability Status Scale (EDSS)**, which is a way to measure disability in people with MS.
  • Must be either not receiving treatment or, if receiving treatment, must be stable on certain allowed medications for at least the past 3 months. These medications include **interferons**, **glatiramer acetate**, **fumarates**, or **teriflunomide**. The treatment should not need to change during the study, except for dose adjustments or switching between allowed medications in Part B of the study.
  • Must weigh at least 45 kg (about 99 pounds) and have a **body mass index (BMI)** of at least 18.0 kg/m². BMI is a measure of body fat based on height and weight.
  • Must use contraception as per local guidelines if applicable, to ensure safety during the study.

Who cannot join the trial?

4 criteria

  • Individuals who do not have a diagnosis of multiple sclerosis cannot participate. Multiple sclerosis is a condition that affects the brain and spinal cord.
  • Participants must be within a specific age range, typically adults, to be eligible.
  • Both males and females are eligible, but certain gender-specific conditions may exclude participation.
  • Individuals who are considered part of a vulnerable population may be excluded. A vulnerable population includes groups like children, pregnant women, or those unable to give consent.
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Investigated drugs

SAR443820 is a medication being studied for its potential effects on serum neurofilament levels in participants with multiple sclerosis. The trial aims to evaluate how this medication impacts these levels compared to a placebo. The study also includes a long-term extension period to observe the durability of its effects over time.

What is already known about the treatment

SAR443820 – This medication is administered orally and is currently being studied in clinical trials for its potential use in treating multiple sclerosis. It is in the experimental phase, with ongoing research to evaluate its effects on serum neurofilament levels, which are markers of nerve damage. The main therapeutic indication is for multiple sclerosis, a condition that affects the central nervous system. SAR443820 works by targeting specific pathways involved in nerve inflammation and damage, aiming to reduce the progression of the disease. It is classified as an investigational drug, with its exact mechanism of action still under study.

Investigated diseases

Multiple Sclerosis – Multiple sclerosis is a chronic disease that affects the central nervous system, particularly the brain and spinal cord. It occurs when the immune system mistakenly attacks the protective covering of nerve fibers, leading to communication problems between the brain and the rest of the body. Over time, this can cause permanent damage or deterioration of the nerves themselves. Symptoms can vary widely, including fatigue, difficulty walking, numbness or tingling, muscle weakness, and problems with coordination and balance. The disease often progresses with periods of new symptoms or relapses followed by periods of remission. The progression and severity of symptoms can differ greatly among individuals.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-509078-45-00Protocol codeACT16753Estimated enrolment280 patientsSponsorSanofi-Aventis Recherche & Developpement

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