Clinical characteristics of middle-aged and older patients with MS treated with interferon beta-1b: post-hoc analysis of a 2-year, prospective, international, observational study

Background: Despite trends towards the increased age of patients living with multiple sclerosis (MS), little is known about the response of older adults with MS to disease-modifying therapies (DMTs). Thus, a post-hoc analysis was undertaken using data from a 2-year, international, non-interventional, prospective cohort study (NCT00787657; BEACON: BEtaferon prospective study on Adherence, COping and Nurse support) of patients above the age of 40 years with MS and starting interferon beta-1b (IFNB-1b) treatment within 6 months before study entry.

Methods: Middle-aged and older patients with MS were divided into two sub-groups: 41-50 years and > 50 years. Treatment with IFNB-1b started within 6 months before study entry. Patients were followed-up for a 2-year observation period. Assessments included disease history and course, annualised relapse rate (ARR), Expanded Disability Scale Score (EDSS), treatment adherence, Hospital Anxiety and Depression Scale (HADS), and adverse events (AE).

Results: At baseline, the intention-to-treat (ITT) population (n = 481) aged 41-50 years (n = 327) and > 50 years (n = 154), had mean (standard deviation [SD]) ages of 45.1 (2.8) and 56.2 (4.2) years, maximum age of 72 years, and duration of MS since onset of symptoms of 3.9 (5.2) and 5.9 (7.1) years, respectively. At baseline, the proportion of patients with relapsing-remitting MS (RRMS) was 96.3 and 94.9 %, and secondary progressive MS (SPMS) was 3.7 and 5.1 %, in the 41-50 and > 50 years sub-groups, respectively. The ARR in the 2 years before study start was 0.93 (0.48) and 0.86 (0.54) for the 41-50 and > 50 years groups, respectively, and decreased since study start to 0.20 (1.09) and 0.07 (0.37), respectively. The percentage of patients with anxiety and depression, as measured by HADS, were stable over the study period. Polypharmacy (five or more medications) was seen in 32.3 and 41.2 % of patients aged 41-50 and > 50 years. No unexpected AEs were reported.

Conclusions: This study provides observational data on patients between 40 and 72 years of age, suggesting that IFNB-1b can be an effective and well-tolerated treatment option in MS patients of advanced age.

Trial registration: ClinicalTrials.gov, NCT00787657.