Biomarkers and Response to Natalizumab for Multiple Sclerosis Treatment

Current state of knowledge of the topic of the project and The general interest of the project; Pharmacogenomic aims to determine biomarkers related to treatment response, a step toward patient-tailored medicine. Natalizumab, a monoclonal antibody has just received the EMEA approval for MS patients who do not respond to interferon treatment or who experience a severe disease course. Efficacy of the drug is outstanding with 37% of the patients completing the "disease free" definition after 2 years (7% in placebo group). On the other hand, natalizumab may be associated with severe adverse events such as progressive multifocal leucoencephalopathy and high costs. Overall, this emphasizes the need beyond current approval criteria to identify those patients with the best efficacy to safety ratio, a major public health issue. Scientific aims The primary scientific aim is to define biomarkers that would allow predicting long term response to natalizumab. Methodology; The investigators plan to conduct a 5 years study to search for the best predicting factors at the beginning of treatment and after 2 years. In this grant application the investigators will perform a multivariate analysis of clinical, MRI, and biological markers (neutralizing antibody, DNA, and mRNA expression) from baseline to 2 years. For feasibility reasons, long term follow up (5 years) and proteomics study will be performed in a second stage.