- Evobrutinib is a Bruton’s tyrokinase (BTK) inhibitor. BTK inhibitors are used to treat blood cancers and are being studied for their effectiveness in MS.
- Researchers conducted two large phase 3 trials comparing evobrutinib to teriflunomide, a treatment for people with relapsing MS.
- Trial results showed that evobrutinib is not more effective than teriflunomide and has a higher risk of causing liver damage. Therefore, evobrutinib is not recommended as a treatment for relapsing MS.
What is evobrutinib?
Evobrutinib is a Bruton’s tyrokinase (BTK) inhibitor and is given orally. BTK inhibitors work by targeting B cells, a type of immune white blood cell that plays an important role in inflammation in MS. Unlike B-cell depleting therapies, BTK inhibitors fine-tune the activity of B-cells, reducing the risk of infections and side effects. They can also cross the blood brain barrier to the brain and spinal cord, meaning they can target immune cells in there.
BTK inhibitors are used to treat blood cancers and are now being studied for use in autoimmune diseases such as MS to reduce the severity of symptoms.
What did the researchers do?
Researchers conducted two large multi-national phase 3 trials (evolutionRMS1 and evolutionRMS2) that compared evobrutinib with teriflunomide (an oral medication that blocks white blood cells from multiplying) in people with relapsing MS.
They assessed the frequency of relapses, the number of new MRI lesions, disability progression, fatigue, and side effects arising in each treatment group for up to 156 weeks.
What did the researchers find?
Published in the Lancet Neurology, the researchers found that the 1,143 people given evobrutinib had similar low rates of relapse compared to the 1,147 people who were given teriflunomide. Both treatment groups also had similar disability progression, number of new lesions, inflammation, fatigue, and rates of side effects.
The trials were conducted from 2020 to 2023, including the time of the COVID-19 pandemic, and the most frequently reported side effect in both treatment groups was COVID-19, followed by raised liver enzymes and headache.
Serious side effects were more frequent in the evobrutinib group, notably high liver enzymes and risk for serious liver damage, but these effects all resolved once treatment was stopped.
Why is this important for people with MS?
Unfortunately, these results indicate that evobrutinib was no more effective than standard treatment in reducing relapse rates, disability progression, number of new lesions, inflammation, fatigue, and rates of side effects. In fact, evobrutinib was found to cause some liver-related side effects.
While these results are disappointing, both positive and negative findings help us understand diseases better, leading to the development of more effective treatments.
