The main purpose of this study is to evaluate the pharmacokinetics (PK) of ocrelizumab administered subcutaneously (SC) in children and adolescents aged 10 to \<18 years with RRMS. The study consists of a 48-week treatment period, an Optional Ocrelizumab Extension (OOE) period of at least 48 weeks, and Safety Follow-up (SFU) for 104 weeks.
Children and adolescents from 10 years to less than 18 years of age, at the time of baseline visit
Body weight ≥25 kg
Diagnosis of RRMS in accordance with the International Pediatric Multiple Sclerosis Study Group (IPMSSG) criteria for pediatric MS, Version 2012, or McDonald criteria 2017 or 2024
Neurologic stability for at least 30 days prior to screening, and between screening and baseline
Participants who are positive for aquaporin 4 (AQP4) or myelin oligodendrocyte glycoprotein (MOG) antibody are not eligible to participate in the study
Any known presence or suspicion of other neurologic disorders that may mimic multiple sclerosis (MS)
History or known presence of recurrent or chronic infection (e.g., human immunodeficiency virus [HIV], syphilis, tuberculosis [TB])
Contraindications against SC injections or other conditions not suitable for SC injections, e.g., extremely thin SC fat layer