Evaluation of the Incidence of Relapses in Patients With Biotin-treated Progressive Multiple Sclerosis

Background: High dose biotin is a therapeutic option for French progressive Multiple Sclerosis (MS) patients, without relapse for at least one year, since June 1, 2016. Despite the inflammatory activity of progressive forms of MS is known to be low, several publications mentioned clinical and/or radiological activity for biotin-treated patients. Objectives: 1. To determine if high dose biotin increase the clinical inflammatory activity of patients with a progressive form of MS. 2. To compare the clinical characteristics of the relapses that occurred with biotin or not. 3. To describe the characteristics of the patients with a clinical inflammatory activity with biotin. Methods: This is a national, academic, observational and retrospective study comparing one group of progressive MS patients with high dose biotin to another group without this treatment using a propensity score, in intention to treat. The main judgment criterion is the annualized relapse rate (ARR) from the beginning of the biotin to the last evaluation available before the data extraction. A Student\'s t test will be used. A negative binomial modelling with relapses counting over a period of exposure and taking into account the inter and intra center variability will be used. The statistical tests will be adapted to the nature of the variables concerning the secondary judgment criteria. Expected results: This French national study will provide a better knowledge of the inflammatory activity of the progressive forms of MS treated with high dose biotin. If an increased clinical inflammatory activity is highlighted with biotin a prospective study will be necessary to confirm the result before a specific information of the scientific community and the patients about this risk or even an amendment of prescription rules in order to secure the use of the product. On the contrary, the absence of increased risk of clinical inflammatory activity with biotin would help to reassure the prescriber and the patient about the innocuity of the treatment.