AntibodyB-CellBeta-interferonCentral Nervous System (CNS)Immune systemInfusion-Related Reactions (IRR)Intravenous (IV) infusionMyelinNeuronPlaceboPMLPPMSPrimary Progressive Multiple Sclerosis (PPMS)Progressive multifocal leukoencephalopathyRelapsing-Remitting Multiple Sclerosis (RRMS)RRMST-Cell