This study is being conducted to evaluate the effectiveness and safety of a medication called remibrutinib, also referred to by the code name LOU064, in individuals living with secondary progressive multiple sclerosis. This condition is a type of autoimmune disease where the body’s immune system attacks the protective covering of nerves, leading to a gradual worsening of physical and cognitive functions over time.

Participants in this trial will receive either the study drug, remibrutinib, in the form of a film-coated tablet taken by mouth, or a placebo. The purpose of the study is to determine if this treatment can help delay the progression of disability. During the study, individuals will be monitored over a period of time to observe how the medication affects their physical abilities and overall health.