A Study to Learn About the Safety of BIIB091 and Its Effect on Brain Inflammation When Taken Alone or With Diroximel Fumarate (DRF) in Adults With Relapsing Forms of Multiple Sclerosis (MS)

Brief summary (registry, in English)

In this study, researchers will learn more about a study drug called BIIB091 in participants with MS who may be experiencing relapses. It is a 2-part study. In Part 1, one set of participants will take either BIIB091 or diroximel fumarate (DRF). In Part 2, a different set of participants will take either a combination of BIIB091 and DRF or DRF alone. The goal of the study is to learn more about the safety of BIIB091 and to compare the effects of the study drug when taken alone or together with DRF. The main question researchers are trying to answer are: * How many participants have new or worsening medical problems (adverse events) after taking BIIB091 or DRF? * How many new areas of inflammation occur in the brain after treatment with BIIB091 and DRF? Researchers will use magnetic resonance imaging (MRI) scans to compare images of the brain before and after treatment. They will also explore the effect of BIIB091 and DRF on the heart using electrocardiograms (ECGs). The study will be done as follows: * After screening, participants who joined Part 1 will be randomly assigned to receive either a high or low dose of BIIB091, or the standard dose of DRF. * The results of Part 1 will be used to choose the best dose of BIIB091 to use in Part 2. * Participants who join Part 2 will be randomly assigned to receive either a standard dose of DRF, a combo of BIIB091 and the standard dose of DRF, or a combo of BIIB91 with a low dose of DRF. * Neither the researchers nor the participants will know which drug or dose the participants will receive in either part of the study. * The treatment period will last 48 weeks in each part of the study. Participants will take the drugs by mouth 2 times a day. * Each part will also have a follow-up safety period that lasts up to 2 weeks. * In total, participants in each part will have 20 study visits, or more if they have a relapse. The total study duration for participants will be up to 54 weeks.

What you commit to

• Study type: Interventional · Phase 2
• Participants enrolled: 127
• From 25 Jul 2023 to the primary completion date, 10 Feb 2026
• 74 sites in 10 countries
• Visits and tests: ask the trial team, the registry does not list them

Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.

Who cannot take part

Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.

Who the study is looking for

Age in the registry: 18 years to 55 years · Sex: All · Does not accept healthy volunteers

Full criteria on ClinicalTrials.gov

Sites (74)

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