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Study on Long-Term Safety of Tolebrutinib and Teriflunomide for 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 long-term safety and tolerability of a medication called tolebrutinib in people with different types of Multiple Sclerosis (MS). MS is a disease that affects the nervous system, and it can be categorized into several types, including relapsing multiple sclerosis (RMS), primary progressive multiple sclerosis (PPMS), and nonrelapsing secondary progressive multiple sclerosis (NRSPMS). The purpose of this study is to understand how safe and tolerable tolebrutinib is for people with these conditions over a long period.

Participants in this study will receive tolebrutinib, which is taken as a film-coated tablet, or a placebo. The study will also involve the use of another medication called Aubagio, which contains the active substance teriflunomide. Some participants may receive a placebo that matches the appearance of Aubagio. The study will monitor participants for any side effects or adverse events that may occur while taking these medications. Additionally, the study will track changes in the participants' condition, such as the progression of disability or the rate of relapses in those with RMS.

The study will last for several years, allowing researchers to gather comprehensive data on the long-term effects of tolebrutinib. Participants will be regularly assessed to ensure their safety and to evaluate the effectiveness of the treatment. The study aims to provide valuable insights into the management of multiple sclerosis and to improve treatment options for those living with this condition.

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 required to have completed a previous Phase 2b or Phase 3 trial involving tolebrutinib. This ensures that participants have prior experience with the medication under investigation.

  2. Step 2

    Medication administration

    Participants will receive tolebrutinib in the form of film-coated tablets. The medication is taken orally. The specific dosage and frequency will be determined by the study protocol and communicated to participants by the study team.

    In some cases, participants may also receive a placebo, which is a substance with no active medication, to compare the effects of tolebrutinib.

  3. Step 3

    Monitoring and assessments

    Throughout the study, participants will undergo regular monitoring to assess the long-term safety and tolerability of tolebrutinib. This includes tracking any adverse events or side effects experienced during the trial.

    Participants may also undergo imaging tests, such as magnetic resonance imaging (MRI), to monitor changes in the brain and nervous system.

  4. Step 4

    Study duration

    The study is designed to continue until August 30, 2029. Participants will be informed of their specific involvement duration, which may vary based on individual circumstances and study requirements.

  5. Step 5

    End of study

    At the conclusion of the study, participants will have a final assessment to evaluate the overall effects of the treatment. This will include a review of any adverse events and changes in their condition.

    Participants will receive information about the study findings and any potential next steps regarding their treatment.

Who can join the trial?

5 criteria

  • Participants must have a type of multiple sclerosis, which is a disease affecting the nervous system. This includes relapsing multiple sclerosis (RMS), primary progressive multiple sclerosis (PPMS), or non-relapsing secondary progressive multiple sclerosis (NRSPMS).
  • Participants should have completed a specific earlier study, either the Phase 2b LTS (LTS16004) or one of the four Phase 3 tolebrutinib trials (EFC16033, EFC16034, EFC16645, EFC16035).
  • Participants who had to temporarily stop the study medication due to a national emergency but completed the trial visits can also join.
  • Both men and women are eligible to participate.
  • The study includes people who might be considered vulnerable, meaning they may need extra care or protection.

Who cannot join the trial?

9 criteria

  • Participants with any other serious health conditions that could interfere with the study.
  • Individuals who are currently participating in another clinical trial.
  • People who have had a recent infection that required treatment.
  • Anyone who has had a recent vaccination within a certain time frame before the study.
  • Individuals with a history of certain types of cancer.
  • Participants who are pregnant or breastfeeding.
  • People with a history of drug or alcohol abuse.
  • Individuals who have had an allergic reaction to similar medications.
  • Anyone with a condition that affects their ability to understand or follow study instructions.
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Investigated drugs

Tolebrutinib is a medication being studied for its long-term safety and tolerability in people with multiple sclerosis. This includes those with relapsing forms of the disease, as well as those with primary progressive or nonrelapsing secondary progressive multiple sclerosis. The goal is to see how well patients can tolerate the medication over an extended period and to monitor any potential side effects.

What is already known about the treatment

Tolebrutinib – Tolebrutinib is administered orally in the form of tablets. It is currently being studied in a Phase 3 clinical trial to assess its long-term safety and tolerability for individuals with various forms of multiple sclerosis, including relapsing and progressive types. The medication is primarily indicated for the treatment of nervous system diseases, specifically multiple sclerosis. At the molecular level, tolebrutinib works by inhibiting Bruton's tyrosine kinase, which plays a role in the immune response, potentially reducing inflammation and nerve damage. It is classified pharmacologically as a kinase inhibitor.

Investigated diseases

  • Relapsing Multiple Sclerosis

    This is a disease where the immune system mistakenly attacks the protective covering of nerves, causing communication problems between the brain and the rest of the body. It is characterized by episodes of new or increasing neurological symptoms, known as relapses, followed by periods of partial or complete recovery. Over time, the disease can lead to a gradual worsening of symptoms and disability. The progression of the disease can vary greatly among individuals, with some experiencing frequent relapses and others having long periods of stability.

  • Progressive Multiple Sclerosis

    This form of multiple sclerosis is marked by a steady worsening of neurological function from the onset of symptoms, without early relapses or remissions. It can be further classified into primary progressive multiple sclerosis, where symptoms gradually worsen from the start, and secondary progressive multiple sclerosis, which follows an initial relapsing-remitting course. The disease progression can lead to increasing disability over time. The rate of progression can vary, with some individuals experiencing a slow decline and others a more rapid deterioration.

Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-503631-18-01Protocol codeLTS17043Estimated enrolment2 666 patientsSponsorSanofi-Aventis Recherche & Developpement

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