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MS research

The TAF-MS 1 study

The TAF-MS 1 study: Tenofovir alafenamide fumarate (TAF) and Epstein-Barr virus activity in people with multiple sclerosis. Here, we investigate the safety and efficacy of tenofovir alafenamide (TAF) on Epstein-Barr virus infection in patients with relapsing-remitting MS.

Type of study: Interventional trial

Coordinating investigator: Øivind Torkildsen

Study director: Kjell-Morten Myhr

Information for patients: on this page (Norwegian only).

Background: Novel insights from the MS research group indicate that infection with the Epstein-Barr Virus (EBV) is the leading cause of MS. As an EBV infection is persistent for life, the virus could function as a trigger or driver of MS-disease activity. If results from a clinical trial could confirm that targeting EBV reduces MS-disease activity, it would result in a paradigmatic change in our understanding of MS and the management of the disease. In collaboration with researchers at Harvard University, Boston, USA, we have identified a highly interesting candidate drug targeting EBV, not yet evaluated in MS patients. This trial could lead to a new paradigm in MS therapy, as it will evaluate a drug that may target the underlying cause of the disease.

The objective of this study is to investigate the safety and efficacy of tenofovir alafenamide (TAF) on Epstein-Barr virus infection in patients with relapsing-remitting MS (RRMS).

Design: This is a randomised double-blinded, placebo-controlled trial comparing the safety and efficacy of tenofovir alafenamide fumarate (TAF) 25 mg daily (n= 25) to placebo (n=25) on EBV viral infection in stable RRMS patients receiving natalizumab therapy. The study is as a part of the EBV-MS Horizon Europe project. 

The primary endpoint is safety and tolerability of the drug, and the key secondary endpoint is change in EBV shedding in the saliva during 6 months of treatment.

Status: Inclusion of patients started early 2024 and was fully recruited (n=50) by February 2025. The follow-up was completed in Q3/Q4 2025, and results are expected to be available by Q1/Q2 2026.

Participating centres

Norway

  • Haukeland University Hospital, Bergen
  • Stavanger University Hospital, Stavanger
  • Førde Hospital, Førde
  • Haugesund Hospital, Haugesund
  • Oslo University Hospital, Oslo
  • Akershus University Hospital, Lørenskog
  • Vestre Viken Hospital, Drammen

Funding

  • The Norwegian MS Society
  • The Regional Health Authority of Western Norway
  • Horizon Europe
  • Meyer Nyquist Legacy
  • The Research Council of Norway, Neuro-SysMed
  • Haukeland University Hospital
  • The University of Bergen
  • Participating hospitals
  • Gilead Sciences, USA
Last updated 7/6/2026