A Study to Investigate the Efficacy of Fenebrutinib in Relapsing Multiple Sclerosis (RMS)

Prior treatment

• Any concomitant disease that may require chronic treatment with systemic corticosteroids or immunosuppressants during the course of the study.
• History of alcohol or other drug abuse within 12 months prior to screening.
• Adrenocorticotropic hormone or systemic corticosteroid therapy within 4 weeks prior to screening.
• Receipt of a live-attenuated vaccine within 6 weeks prior to randomization.
• Any previous treatment with immunomodulatory or immunosuppressive medication without an appropriate washout period.

Other illness

• Any known or suspected active infection at screening, including but not limited to a positive screening tests for Hepatitis B and C, an active or latent or inadequately treated infection with tuberculosis (TB), a confirmed or suspected progressive multifocal leukoencephalopathy (PML).
• History of cancer including hematologic malignancy and solid tumors within 10 years of screening.
• Presence of other neurological disorders that could interfere with the diagnosis of MS or with the assessments of safety or efficacy during the study.
• Clinically significant cardiovascular, psychiatric, pulmonary, renal, hepatic, endocrine, metabolic or gastrointestinal disease.
• History of or currently active primary or secondary (non-drug-related) immunodeficiency, including known history of human immunodeficiency virus (HIV) infection.

Age

• Disease duration of \> 10 years from the onset of symptoms and an EDSS score at screening \< 2.0.

Other

• Female participants who are pregnant or breastfeeding, or intending to become pregnant.
• Male participants who intend to father a child during the study.
• A diagnosis of Primary Progressive Multiple Sclerosis (PPMS) or non-active Secondary Progressive Multiple Sclerosis (SPMS).
• Inability to complete an MRI scan.

• A diagnosis of RMS in accordance with the revised 2017 McDonald Criteria.
• Expanded Disability Status Scale (EDSS) score of 0 - 5.5 at screening.
• For female participants of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures, and refrain from donating eggs.
• For male participants: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures, and refrain from donating sperm.