Prospective, Longitudinal, Multicenter Observational Study of Long-term Treatment with Intramuscular Interferon β-1a of Patients with Clinically Isolated Syndrome at High Risk of Conversion

Abstract

Introduction: Early initiation of treatment with intramuscular (IM) interferon (IFN) β-1a in patients with a single demyelinating event suggestive of multiple sclerosis (MS) has been shown to reduce the risk of a second event. This study investigated the characteristics of patients with clinically isolated syndrome (CIS), conversion to clinically definite MS and quality of life (QoL) in clinical practice. Methods: Patients eligible for IM IFNβ-1a for CIS were followed for 4 years (1 visit every 6 months, 9 visits in total). Disease progression was assessed using the Expanded Disability Status Scale (EDSS). The rate of conversion, adverse events and laboratory parameters were reported. Patients were administered QoL questionnaires (Functional Assessment of Multiple Sclerosis [FAMS] and EuroQol 5D [EQ-5D]). Results: Thirty-four patients from 15 Spanish hospitals were included and 18 completed the study. The mean ± SD age of the patients was 32.1 ± 9.08 years and 64% were women. At baseline, the mean EDSS was 0.94 ± 0.85. During follow-up, mean EDSS ranged from 0.89-1.25 and 15 patients (45.5%) converted to CIS. The most common adverse reaction was flu-like syndrome (55%). One patient discontinued treatment due to flu-like syndrome. The mean score on the visual analogue scale of the FAMS and the EQ-5D remained constant throughout the study (p>0.05 with respect to baseline). Conclusions: The conversion rate was higher than in the immediate-treatment arm of CHAMPIONS study, which could be expected due to differences in the patient population and delays in treatment initiation. The added value of the present study lies in the prospective collection of data from the clinical practice in highrisk CIS patients treated with IM IFNβ-1a in Spain. To our knowledge, this is the first study published with these characteristics.