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Frexalimab: an experimental anti-CD40L antibody in Phase 3 studies for MS

Published by MyelinWatch:

Organisation
Sanofi · France
Study sponsor
Sanofi

Frexalimab (SAR441344) · Frexalimab (SAR441344) is an experimental antibody from Sanofi that blocks CD40 ligand (CD40L), a molecule that helps immune cells activate one another. It is given into a vein or as an injection under the skin. Phase 3 studies compare it with teriflunomide in relapsing MS (FREXALT) and with placebo in non-relapsing secondary progressive MS (FREVIVA); a smaller Phase 3 study, Frexcite, compares the two ways of giving it.

What is being studied

Frexalimab (SAR441344) is an experimental antibody from Sanofi that blocks CD40 ligand (CD40L), a molecule that helps immune cells activate one another. It is given into a vein or as an injection under the skin. Phase 3 studies compare it with teriflunomide in relapsing MS (FREXALT) and with placebo in non-relapsing secondary progressive MS (FREVIVA); a smaller Phase 3 study, Frexcite, compares the two ways of giving it.

Research stage

Large study to confirm benefit and safety

The current listing is open to participants.

What we know so far

In a Phase 2 study in 129 people with relapsing MS, published in the New England Journal of Medicine in 2024, people on frexalimab had fewer new active (gadolinium-enhancing) brain lesions on MRI at week 12 than people on placebo: on average 0.2 with the higher dose into a vein and 0.3 with the lower dose under the skin, against 1.4 with placebo (rate ratios 0.11 and 0.21). This is an MRI measure over a short period in a small study, not proof that relapses or disability are reduced. No Phase 3 results are available yet.

What this means for patients today

Frexalimab is not an approved treatment; it is given only within studies. FREXALT and FREVIVA list sites in Greece but are no longer accepting new participants. The smaller Phase 3 study Frexcite is listed as accepting participants in some countries, with no site in Greece. The long-term extension study, authorised in 11 EU countries, including Greece on 2 November 2026, is only for people who complete earlier frexalimab studies, and it has not started accepting participants. Access to frexalimab in Greece outside these studies is not established.

Next documented step

Estimated EU recruitment start of the long-term extension study: 15 February 2027, according to its CTIS record

Treatment or approach
Frexalimab • experimental anti-CD40L antibody for relapsing and non-relapsing secondary progressive MS
How it is intended to work
Monoclonal antibody that blocks CD40 ligand (CD40L)
Where the study is running
Multinational; FREXALT and FREVIVA list sites in Greece but are not accepting new participants; the extension study was authorised in Greece on 2 November 2026, lists four Greek hospitals and has not started accepting participants
Source: ClinicalTrials.gov (US National Library of Medicine) — FREXALT (NCT06141473); sponsor Sanofi — official ClinicalTrials.gov record ↗Source: ClinicalTrials.gov — FREVIVA (NCT06141486), Phase 3, ongoing, not accepting new participants ↗ Source: ClinicalTrials.gov — Frexcite (NCT07325292), Phase 3, accepting participants ↗ Source: ClinicalTrials.gov — Phase 2 study (NCT04879628) with posted results ↗ Source: New England Journal of Medicine, 2024 — Phase 2 results (DOI 10.1056/NEJMoa2309439) ↗ Source: CTIS — extension study LTS18002 (2026-525688-41-00) ↗
Published by MyelinWatch
Last substantive MyelinWatch update

Programme updates — newest research developments first

  1. Phase 3 extension study authorised in Greece; recruitment not yet startedResearch event/source date:

    Frexalimab: Greece authorises the long-term Phase 3 extension study

    The EU Clinical Trials Information System (CTIS) shows that Greece authorised Sanofi's Phase 3 extension study LTS18002 (2026-525688-41-00) on 2 November 2026. Denmark, Portugal and Poland authorised it on the same day, after Belgium (30 October 2026) and Austria (1 November 2026); all six countries are listed as authorised with recruitment pending. The record plans 17 participants in Greece and lists four Greek hospitals: AHEPA University General Hospital of Thessaloniki, the University General Hospital of Ioannina, the General University Hospital of Larissa and the 401 General Military Hospital of Athens. The study will look at the long-term safety and tolerability of frexalimab, an experimental antibody, in people with multiple sclerosis (MS). It is open only to people who complete earlier frexalimab studies on the study drug, such as the Phase 3 studies FREXALT and FREVIVA. The estimated EU recruitment start is 15 February 2027.

    Source: EU Clinical Trials Information System (CTIS), European Medicines Agency — official CTIS record ↗Source: ClinicalTrials.gov — FREXALT (NCT06141473), Phase 3, ongoing, not accepting new participants ↗ Source: ClinicalTrials.gov — FREVIVA (NCT06141486), Phase 3, ongoing, not accepting new participants ↗

  2. Phase 3 extension study authorised in two EU countries; recruitment not yet startedResearch event/source date:

    Frexalimab: long-term Phase 3 extension study authorised in Belgium and Austria

    The EU Clinical Trials Information System (CTIS) shows that Belgium authorised Sanofi's Phase 3 extension study LTS18002 (2026-525688-41-00) on 30 October 2026 and Austria on 1 November 2026. The study will look at the long-term safety and tolerability of frexalimab, an experimental antibody given into a vein or under the skin, in people with multiple sclerosis (MS). It is open only to people with relapsing MS or non-relapsing secondary progressive MS who complete earlier frexalimab studies on the study drug, including the Phase 3 studies FREXALT and FREVIVA. It plans 1,710 participants in total. Both countries are listed as authorised with recruitment pending; the estimated EU recruitment start is 15 February 2027.

    Source: EU Clinical Trials Information System (CTIS), European Medicines Agency — official CTIS record ↗Source: ClinicalTrials.gov — FREXALT (NCT06141473), Phase 3, ongoing, not accepting new participants ↗ Source: ClinicalTrials.gov — FREVIVA (NCT06141486), Phase 3, ongoing, not accepting new participants ↗