Remibrutinib, also called LOU064, is an experimental oral medicine being evaluated as a means to reduce inflammation in relapsing forms of multiple sclerosis (MS).
Novartis, which is developing the therapy, also is investigating its use in another inflammatory disorder called chronic spontaneous urticaria, characterized by itchy hives and swelling under the skin.
MS is an autoimmune condition in which the body launches an immune response that damages nerve cells in the central nervous system (the brain, spinal cord, and optic nerves). This inflammatory response results in progressive nerve cell death and a range of MS symptoms.
Remibrutinib is an oral treatment that potently and selectively inhibits the Bruton’s tyrosine kinase (BTK) enzyme, which plays a critical role in the inflammatory activity of certain immune cells such as B-cells and microglia. By blocking this protein, remibrutinib is expected to dampen the inflammatory activity that drives MS.
Similar to other BTK inhibitors in development, this medication is known to bind to BTK covalently — which means that once a molecule of remibrutinib binds to a BTK protein, that protein is permanently neutralized. However, this molecule specifically binds to BTK in its inactive state, which forces the protein to remain in that inactive state.
Remibrutinib is available in film-coated tablets taken orally. A Phase 1 clinical trial tested the medication in healthy volunteers at doses up to 600 mg per day. A 100 mg dose, taken twice daily, is now being investigated in two ongoing Phase 3 trials.
Novartis conducted a Phase 1 clinical trial to evaluate the safety and pharmacological properties of the therapy in healthy volunteers. The study enrolled 156 participants, who were given various doses and dosing schedules of remibrutinib, for up to 12 days of treatment in total.
Results showed that doses up to 600 mg per day were well-tolerated, and no serious safety-related events or treatment discontinuations were reported. Pharmacological data indicated that remibrutinib is rapidly absorbed and eliminated from the body, and that food had no notable effect on its absorption.
Two identically designed Phase 3 clinical trials are now ongoing and recruiting participants at dozens of sites in the U.S. and several in Spain. One trial (NCT05156281) also includes locations in Slovakia and France, while the other study (NCT05147220) has sites in Poland.
Each study aims to enroll 800 patients ages 18 to 55 with relapsing forms of MS, including relapsing-remitting MS and active secondary progressive MS.
Participants will be randomly assigned to receive remibrutinib at a 100 mg dose twice daily or Aubagio (teriflunomide), an approved oral MS therapy, for 30 months. Both trials are double-blinded, meaning that neither the researchers nor the participants know which patient is getting the medication and which the placebo.
Those completing the study may then join an open-label extension study, in which all participants will receive remibrutinib for up to five years.
The main goal is to compare the effect of the treatments on relapse rates after 30 months. The trials also will also assess outcomes related to safety, disability progression, MRI measures of disease activity, and quality of life. Top-line data from the trials are expected by October 2025.
Because the clinical trials in MS are all ongoing, the most common side effects of fenebrutinib in patients with this neurodegenerative disorder are still unknown. In a Phase 1 clinical trial in healthy volunteers, the most commonly reported side effects were headache and diarrhea.
Multiple Sclerosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
Remibrutinib is an experimental medication that has not been approved to treat multiple sclerosis (MS) or any other indication. The therapy is designed to block the activity of a protein called Bruton tyrosine kinase, which is important for the activity of certain immune cells that contribute to MS damage. By inhibiting this protein, this medication is expected to reduce the inflammatory autoimmune attack that drives MS.
Remibrutinib is undergoing testing in multiple sclerosis patients in Phase 3 clinical trials. If the results are positive, it is possible that they could support future applications seeking the medicine’s approval from regulators in the U.S. or elsewhere. However, it is too early to say if or when the therapy might be approved.
Clinical trials testing remibrutinib in multiple sclerosis patients are not enrolling people who are pregnant or breastfeeding. Moreover, all participants with the ability to reproduce are required to use effective methods of contraception. It is unknown if this treatment can safely be taken during pregnancy.
There are not yet any clinical data available on the potential efficacy of remibrutinib in people with multiple sclerosis. Top-line data from the ongoing Phase 3 trials are expected in 2025.
Neither hair loss nor weight gain was reported as a side effect of remibrutinib in a Phase 1 trial that tested the medication in healthy volunteers. Patients who experience unexpected reactions to new medicines are advised to talk to their healthcare providers.
Get regular updates to your inbox.
