[Long-term treatment for multiple sclerosis with interferon beta-1b. Outcomes of an open, retrospective, observational study].

Objective: To assess the outcomes of long-term treatment in multiple sclerosis (MS) patients with Infibeta (interferon beta-1b).

Material And Methods: The article presents the results a real-world, multicenter, retrospective, observational study of treatment with interferon beta-1b. We enrolled 332 patients with MS who had been receiving Infibeta for at least 8 years. 60.2% of them had a relapsing-remitting MS (RRMS). 73.2% patients received only interferon beta-1b that was initial DMT.

Results: During the first year of the treatment, 66% of the patients reported no relapses regardless of the MS type. No relapses in the 8 year of treatment were observed in 86.9% of patients with RRMS and 77.7% with secondary progressive MS (SPMS). The median number of relapses during the whole follow-up period in RRMS patients was 1. The time to first relapse in the subgroup of patients who received interferon beta as the first treatment was longer compared to other treatment (median 4 and 2, respectively, =0.0017). 42% of patients with RRMS remained progression-free during 8 years of follow-up. The flu-like syndrome was observed in 61.7% for the first year of treatment; in 36.3% it was periodically and was mild in 71.3%.

Conclusion: The study outcomes confirm a high clinical response to the long-term treatment with Infibeta in patients with RRMS and SPMS and demonstrate that interferon beta-1b is one an optimal option for the initial treatment of patients with moderate disease activity.