The Cost of Patients With Relapsing-Remitting Multiple Sclerosis Who Develop Neutralizing Antibodies While Treated With Interferon Beta.

Materials and methods: The study was based on a mixed method, based partly on real-world data on 546 RRMS patients treated with IFNβ from a previous observational study [1], and partly from the review of cost studies in the published literature. Reverting and fluctuating patients were not considered in this evaluation. EDSS level (measured at 630 months) and average relapse rates were analysed in a subgroup of nearest-neighbor (NN) matched subjects (67 NAb+ and 59 NAbpatients; matching covariates: gender, age at the beginning of IFNβ, baseline EDSS and disease activity) [Table 1]. Routine management costs and relapse costs were obtained from the literature [2,3]. The perspective was the Italian National Healthcare Service (NHS) and the Italian Society.