Interferon Beta-1b for the Treatment of Multiple Sclerosis – More than 10 Years of Experience

Objective: Interferon beta-1b (IFNβ-1b) was the first disease-modifying agent (DMT) used for the treatment of multiple sclerosis (MS). We aimed to evaluate the first patients with MS that started treatment in our clinic.
Methods: An observational, retrospective study was performed on 78 patients that had continuous treatment with IFNβ-1b for more than 10 years. The collection of the demographical data and periodical clinical evaluation was performed on all patients. The disability was quantified using the Expanded Disability Status Scale (EDSS), creating two groups of patients, G1: EDSS < 4.0 and G2: EDSS ≥ 4.0. The hallmarks of the disability evolution were gathered by direct patient interview, such as the symptoms at onset and relapse frequency.
Results: After more than 17 years of disease evolution, more than half (65.38%) of the patients present a mild disability score. The majority (54.90%) started treatment in the first three years after the onset, while the patients in G2 started treatment after more than 3 years from the onset. The initiation of IFNβ-1b lead to a significant reduction of the relapse rates. A reduced number of patients (<25%) transitioned from RRMS to SPMS.
Discussion: Continuous evaluation of MS patients allows us to assess the possibility of prolonged treatment with IFNβ-1b and to differentiate the responders from non-responders. The clear reduction in relapse rates and disability progression, notably in patients that started treatment early ensure us into continuing administering this medication. Compared to historical cohorts, our lot had a slower disability evolution and a significant proportion hadn’t reach an important disability score.