Assessment of Ocrelizumab (OCR) Treatment Effects on Functional Impairment of MS Patients Enrolled in the Phase III Orchestra Programme Using Multimodal Evoked Potentials (EP) and Highresolution Electroencephalography (EEG)

Multiple Sclerosis (MS) is not only an 'inflammatory' demyelinating disease, but also includes axonal and neuronal injury in the grey matter . Neurodegenerative processes are partly independent of lesion formation and relapse activity , but represent the direct driver of clinical long-term disability and cognitive decline.

Multimodal evoked potentials (EP), i.e. the combination of visual, somato-sensory and motor EP (VEP, SSEP, MEP) have been shown prospectively to provide objective, monovectorial, and numerical data which are closely correlated to the EDSS. As EP capture the functional integrity of the examined systems they represent a method unbiased for directional changes, while remaining specific for the neuronal function, and hence can measure deterioration, as well as improvement, a germane advantage to capture drug response.

High-resolution electroencephalography (EEG) allow for explorative analysis of potential surrogate markers for cognitive decline.

Ocrelizumab (OCR), a humanized anti-CD20 monoclonal antibody has shown strong treatment effects on number of T1Gd-enhancing lesions , on new T1Gd-enhancing and new T2-hyperintense lesions as well as on the annualized relapse rate in a recent phase II trial in relapsing-remitting MS.

The present study will investigate the effects of OCR on multimodal evoked potentials (EP), Furthermore, quantitative EEG as a potential correlate of cognitive dysfunction and fatigue will be explored.