A Study to Evaluate the Efficacy and Safety of Remibrutinib in Secondary Progressive Multiple Sclerosis

The purpose of this study is to provide efficacy and safety data for remibrutinib in patients with secondary progressive multiple sclerosis (SPMS)

This is a Phase III, randomized, double-blind, placebo-controlled, multi-center, parallel-group, event-driven study to evaluate the efficacy, safety and tolerability of remibrutinib in SPMS patients. Approximately 1275 eligible participants will be randomized to receive either remibrutinib or matching placebo. The study consists of an event-driven Core Part with double-blind treatment, followed by an Extension Part with open-label remibrutinib treatment.

Inclusion Criteria: * Signed informed consent must be obtained prior to any assessment performed. * Male or female participants aged 18-65 (inclusive) at Screening. * Diagnosis of SPMS according to the 2017 revised McDonald criteria (Thompson et al 2018) at Screening. * Absence of documented clinical relapses in the 24 months before Screening and randomization. * EDSS score of 3.0 to 6.0 (inclusive) at Screening. * Documented evidence of disability progression in the 12 months before Screening. Exclusion Criteria: * Unwilling or unable to undergo MRI scans as per protocol (for example, claustrophobia, or presents absolute contraindications to MRI (e.g., metallic implants, metallic foreign bodies, pacemaker, defibrillator)). * History of clinically significant central nervous system (CNS) disease (e.g. stroke, traumatic brain or spinal injury, history or presence of myelopathy) or neurological disorders which may mimic multiple sclerosis (MS). * Ongoing substance abuse (drug or alcohol) or any other factor (e.g. serious psychiatric condition) that may interfere with the participant's ability to cooperate and comply with the study procedures. * Participants with history of confirmed Progressive Multifocal Leukoencephalopathy (PML) or neurological symptoms consistent with PML. * Women of childbearing potential (WOCBP), defined as all women physiologically capable of becoming pregnant from menarche until becoming post-menopausal, unless they are using highly effective methods of contraception (failure rate \< 1% per year) while taking study treatment and for at least 1 week after stopping study treatment. * Significant bleeding risk or coagulation disorders, at Screening. * Use of exclusionary medication prior to Screening/randomization as listed in the protocol. Other protocol-defined inclusion/exclusion critria may apply