Fenebrutinib

Fenebrutinib is a new drug being investigated for the treatment of relapsing and primary progressive MS. Phase 2 and 3 trials are currently recruiting people with relapsing and primary progressive MS.

About fenebrutinib

Fenebrutinib is part of a new class of drugs called Bruton’s tyrosine kinase (BTK) inhibitors. BTK is a molecule that affects the activity of some immune cells. Stopping BTK working properly reduces the activity of these immune cells.

These cells have been linked to MS relapses and progression. Researchers believe reducing their activity could reduce the damage caused to nerves.

Unlike the other BTK inhibitors, fenebrutinib has a unique, reversible mechanism. Roche, the company behind fenebrutinib, argue that this reversible mechanism will create a better, safer treatment against MS compared to its competitors.

As a tablet, once daily.

Phase 3 trial – relapsing MS

Roche are aiming to recruit 736 people with relapsing MS for a phase 3 clinical trial. Participants will take either fenebrutinib or teriflunomide (Aubagio). Researchers will compare the efficacy and safety of the two treatments and want to know whether fenebrutinib is better at reducing relapses. They’ll also be looking at worsening of disability and lesions visible on MRI scans. The estimated completion date is November 2025.

Find out more about this clinical trial

Phase 3 trial – primary progressive MS

Roche are aiming to recruit 946 people with primary progressive MS for a phase 3 clinical trial. Participants will take either fenebrutinib or ocrelizumab (Ocrevus). Researchers will compare the efficacy and safety of the two treatments and want to know whether fenebrutinib is better at slowing the MS progression. They’ll also be looking at changes in brain volume and cognition. The estimated completion date is May 2028.

Find out more about this clinical trial

A phase 1 clinical trial to test the safety profile of fenebrutinib in people without MS was completed in 2018. The results of this trial were published in a peer-reviewed journal in June 2018. The authors found that fenebrutinib is well tolerated and poses no obvious safety concerns.

Read the full research paper here

Fenebrutinib has not yet been widely tested in people with MS, so its side effects specifically for people with MS are not yet known.

Fenebrutinib has not been widely tested in people with MS so it isn’t yet known how it compares to existing MS treatments.

Fenebrutinib is currently being investigated in two phase 3 trials, with results due in 2025 and 2028. If the results are positive, fenebrutinib will be submitted for regulatory approval.

Positive trial results can only make a real difference to people with MS once a regulator like the European Medicines Agency concludes there's sufficient evidence the drug is safe and effective.