LAUSR

Background Ocrelizumab (OCR) is a humanised monoclonal antibody that selectively targets CD20+B cells. The pathogenesis of multiple sclerosis (MS), including neurodegeneration, is thought to be influenced by B cells. Volumetric magnetic resonance imaging (MRI) measurements can be used to assess neurodegeneration. Objective To evaluate the effect of OCR vs interferon beta-1a (IFN β -1a) on brain MRI markers of neurodegeneration in patients with relapsing MS enrolled in two identical Phase III, randomised, double-blind, double-dummy trials (OPERA I and OPERA II). Methods In OPERA I and OPERA II, patients were randomised (1:1) to receive OCR 600 mg via intravenous infusion every 24 weeks or subcutaneous IFN β -1a 44  μ g three-times weekly over 96 weeks. MRI endpoints thought to be related to neurodegeneration included the change in whole brain volume, change in cortical grey matter volume and change in cerebral white matter volume. Results Compared with IFN β -1a, OCR reduced the rate of whole brain volume loss from baseline to Week 96 by 23.5% ( p p  = 0.0001), and from Week 24 to Week 96 by 22.8% ( p  = 0.0042) and 14.9% ( p  = 0.0900) in OPERA I and OPERA II, respectively. OCR-treated patients showed a smaller mean percentage of cortical grey matter volume loss compared with IFN β -1a from baseline to Week 96, with a mean difference of 0.273% ( p  = 0.0005) in OPERA I and 0.516% ( p β -1a from baseline to Week 96, with a mean difference of 0.261% ( p  = 0.0024); in OPERA II, there was no difference ( p  = 0.2748) in cerebral white matter volume loss in patients treated with OCR compared with IFN β -1a from baseline to Week 96. Conclusion The rate of neurodegeneration as measured by whole brain, cortical grey and cerebral white matter volume loss on MRI was reduced by OCR compared with IFN β -1a in patients with relapsing MS over 96 weeks. This study is sponsored by F. Hoffmann-La Roche Ltd.