As part of the Covid-19 pandemic, some neurologists have alerted the French authorities (ANSM: National Medicines Safety Agency) to the interruption of natalizumab treatment by some MS patients. The ANSM has granted temporary home use of natalizumab within the framework of a at-home hospitalization (HAD) program. The study purpose is to assess at-home natalizumab administration regarding safety, disease activity, quality of life, patient's perception and costs by comparing outcomes before and after At Home natalizumab treatment strategy.~The study consists of two periods of observation: a retrospective one corresponding to the year prior the study entry and a prospective one corresponding to patient follow-up for one year from the date of the patient inclusion. The date of the inclusion corresponds to the natalizumab-infusion conducted at hospital just before infusions hospital at-home started. Retrospective data are collected from medical record and a minimal dataset is needed to enroll the patient regarding MRI activity and safety data (i.e., nature and number of SAE and selected AE of grade 2 the year prior study entry).~The prospective period consists of 10 at-home natalizumab infusions (months 1-5 and 7-11) and 3 at-hospital natalizumab infusions (inclusion, months 6 and 12) according to standard care. In addition to clinical, MRI and safety (SAE and selected AE of grade 2) data collected as part of standard medical care from medical record over all the study period, Quality of life (EQ-5D-5L, MusiQol) and patient's preference (Musicare) questionnaires will be administered at inclusion and months 6 and 12 and clinical global impression of change will be recorded at month 6 and 12. Patients will be asked to notify any adverse events that may occur between each at-home infusion and to record each month his/her healthcare resource consumption in a diary. Patients will be contacted each month after at-home infusion to record safety and healthcare resource consumption data.~For a sub-group of 15 patients qualitative interview will be performed between month 3 and 8 as part of patient preference assessment.~Micro-costing dedicated forms and experts' statements will be used to assess resource utilization associated to natalizumab infusion during each period for medico-analyze purpose.
At-home use of Natalizumab in multiple sclerosis (MS) patients has been temporarily granted by French security agency of medicines and Health products (ANSM). The main objective of the study is to compare the safety of natalizumab administration at home vs at hospital based on retrospective and prospective data collection. Quality of life, patient perception of at-home natalizumab administration are also evaluated as secondary objectives as well as medico-economic assessment of the method.~Data will be collected for a 12-month retrospective period and a 12-month prospective period.