Frexalimab

Frexalimab blocks a protein immune cells use to talk to each other called CD40 ligand (CD40L). This protein usually helps activate parts of the immune system that contribute to inflammation and damage in MS. 

By blocking CD40L, frexalimab aims to reduce inflammation in the brain and spinal cord. Research so far suggests it could reduce relapses and protect nerves from damage to slow progression of MS.

Frexalimab is given as an injection under the skin.  

Two phase 3 trials began in late 2023. 

FREXALT trial

FREXALT is testing frexalimab in people with relapsing MS. It’s comparing it to teriflunomide (Aubagio), an existing MS treatment. Researchers are measuring how often people on the trial have relapses and whether the drug can slow disability progression.

Find out more about the FREXALT trial

FREVIVA trial

FREVIVA is studying frexalimab in people with non-relapsing secondary progressive MS. This trial is comparing frexalimab with a placebo to see whether it can slow down the worsening of disability.

Find out more about the FREVIA trial

These ongoing Phase 3 trials will provide more comprehensive data on how well the drugs work over time.

Results from an earlier phase 2 trial (CHANGE-MS) were published in February 2024. It showed people with relapsing MS who took frexalimab had fewer new MS lesions than people who took a placebo. 

As well as looking at new lesions, the researchers looked at levels of neurofilament light chain (NfL) in the blood. This is a marker of nerve damage – lower levels suggest less damage is happening. People who took frexalimab had lower NfL levels than those on placebo, which suggests the drug could protect nerves from damage and slow progression of MS.

Read the full results of the CHANGE-MS trial

So far, there have been mild side effects in trial:

• Reactions at the injection site
• Headaches
• Mild infections

Frexalimab hasn’t been compared to existing MS treatments yet. 

Phase 3 trials started in late 2023 and are expected to take several years to complete. If the results are positive the drug would then need to be approved by regulators.