This open label, single arm study will evaluate the PK and PD effects of fenebrutinib in children and adolescents with RMS aged between 10 and \< 18 years.
This study consists of a Dose Exploration Period and an Optional Extension Period. Eligible participants may choose to continue treatment with fenebrutinib in the optional extension period after completing the dose exploration period.
A diagnosis of RMS in accordance with the International Pediatric Multiple Sclerosis Study Group (IPMSSG) criteria for pediatric MS, Version 2012, and the revised 2017 McDonald Criteria and one or more of the following: at least one MS relapse during the previous year or two MS relapses in the previous 2 years or evidence of at least one Gd enhancing lesion on MRI within 6 month
Expanded Disability Status Scale (EDSS) at screening from 0 to 5.5 points, inclusive
Children and adolescents must have received all childhood vaccinations as per local/national recommendations for childhood vaccination against infectious diseases
A diagnosis of primary progressive multiple sclerosis (PPMS) or non-active secondary progressive multiple sclerosis (SPMS)
Potentially confounding neurological, somatic, or metabolic disorders
Current clinically significant psychiatric or medical illness
History of cancer, transplants, or bleeding disorders