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Study on the Safety of Tenofovir Alafenamide and Natalizumab for People 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 medication called Tenofovir Alafenamide in people with Multiple Sclerosis (MS). MS is a condition that affects the brain and spinal cord, leading to a range of symptoms such as problems with vision, arm or leg movement, sensation, or balance. The study will explore how safe it is to use Tenofovir Alafenamide alongside another medication called Natalizumab, which is already used to treat MS. The trial will also look at the activity of the Epstein-Barr virus (EBV) in people with MS, as EBV is a common virus that can be found in the body.

Participants in the study will receive Tenofovir Alafenamide in the form of film-coated tablets, taken orally, and Natalizumab as a solution for infusion. The study will last for about six months, during which time the safety of the treatment combination will be closely monitored. The trial aims to understand if adding Tenofovir Alafenamide to the current treatment with Natalizumab is safe and how it affects the presence of EBV in the body.

Throughout the study, researchers will observe any serious side effects and changes in the levels of EBV in saliva. The study will also measure changes in certain antibodies, which are proteins made by the immune system to fight infections. These observations will help determine the impact of the treatment on the virus and the overall health of the participants. The goal is to gather information that could lead to improved treatment options for people with MS.

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 meeting specific criteria: age between 18 and 70, a diagnosis of relapsing-remitting multiple sclerosis (RRMS), current treatment with natalizumab, and evidence of Epstein-Barr virus (EBV) in saliva.

  2. Step 2

    Initial assessment

    An initial assessment is conducted to establish baseline measurements. This includes checking the number of serious adverse events (SAEs) and measuring EBV levels in saliva.

  3. Step 3

    Treatment phase

    The treatment involves continuing the current natalizumab therapy, administered as a 300 mg infusion, and adding tenofovir alafenamide (TAF) as an oral tablet of 25 mg.

    The objective is to evaluate the safety of TAF when used alongside natalizumab.

  4. Step 4

    Follow-up assessments

    Follow-up assessments occur at 2, 8, and 24 weeks after starting the treatment. These assessments measure changes in EBV levels in saliva and changes in IgG antibodies to EBV antigens.

  5. Step 5

    Completion of study

    The study concludes 24 weeks after the start of the treatment. The total number of SAEs and changes in EBV shedding are evaluated to determine the study's outcomes.

Who can join the trial?

4 criteria

  • Patients must be between the ages of 18 and 70 years old. Both men and women can participate.
  • Patients must have a diagnosis of relapsing-remitting multiple sclerosis (RRMS). This is a type of multiple sclerosis where symptoms flare up and then improve.
  • Patients must currently be receiving treatment with natalizumab, a medication used to treat multiple sclerosis.
  • Patients must show shedding of EBV in their saliva. This means that a saliva test must show more than 5.8 copies of the Epstein-Barr virus (EBV) per microliter.

Who cannot join the trial?

4 criteria

  • Patients who are not diagnosed with multiple sclerosis cannot participate. Multiple sclerosis is a condition that affects the brain and spinal cord.
  • Patients who are not within the specified age range for the study cannot participate. The age range is not specified in the provided data.
  • Patients who are not able to safely use the study medication, TAF, as an additional treatment to natalizumab cannot participate. Natalizumab is a medication used to treat multiple sclerosis.
  • Patients who are part of a vulnerable population, such as those who cannot give informed consent, cannot participate.
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Investigated drugs

  • Tenofovir Alafenamide Fumarate (TAF)

    is being studied to see if it is safe to use alongside another medication for people with multiple sclerosis (MS). It is being tested to understand its effects on the Epstein-Barr virus, which is thought to play a role in MS.

  • Natalizumab

    is a medication already used to treat multiple sclerosis. In this study, it is used as a standard treatment, and researchers are looking at how safe it is to add TAF to this existing therapy.

What is already known about the treatment

Tenofovir Alafenamide Fumarate – This medication is administered orally in tablet form. It is currently being studied in clinical trials for its potential use in treating multiple sclerosis, particularly in combination with natalizumab. The main therapeutic indication being explored is its effect on Epstein-Barr virus activity in people with multiple sclerosis. At the molecular level, Tenofovir Alafenamide Fumarate works by inhibiting viral replication, which may help in reducing the activity of viruses associated with multiple sclerosis. It is classified as an antiviral medication.

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 sheath (myelin) that covers nerve fibers, leading to communication problems between the brain and the rest of the body. Over time, the disease 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 progression of multiple sclerosis can be unpredictable, with periods of remission and relapse. The severity and specific symptoms can differ greatly from person to person.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-503814-62-00Estimated enrolment50 patientsSponsorHelse Bergen HF

sourced from the EU Clinical Trials Register and site verification

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