Discontinuation of disease-modifying therapy in MS patients over 60 years old and its impact on relapse rate and disease progression

Abstract

Background / aims: The benefit of disease-modifying therapy (DMT) is unclear for older patients with multiple sclerosis (MS), namely those who have not experienced clinical disease activity for a prolonged time. We aimed to compare baseline differences and clinical outcomes between DMT discontinuers and continuers in a cohort of MS patients older than 60 years.

Methods: Retrospective, observational study identifying MS patients aged over 60 years, stable on DMT> 24 months. Additional inclusion criteria were a previous diagnosis of relapsing MS and a minimum follow-up period of 24 months. Differences between groups (continuers/discontinuers) were assessed. For risk of relapse and of confirmed disability worsening at follow up, a time to outcome survival model was constructed using Cox proportional hazards regression, testing for possible risk predictors.

Results: Thirty-five patients were included (68.6% female), with a mean age at diagnosis of 42.1 ( ± 9.5) years and a median EDSS score of 3 (IQR 2) at the age of 60 years (baseline). Thirteen patients discontinued DMT after baseline, in a mean follow-up time of 77.1 months ( ± 40.2). No differences were found between DMT continuers vs discontinuers. DMT discontinuation did not predict risk to relapse (HR 0.38, 95%CI 0.04-3.80, p = 0.408) or disability worsening at follow-up (HR 0.83, 95%CI 0.31-2.22, p = 0.712). MRI gadolinium-enhancing lesions and EDSS score > 3 at baseline were found to be independent predictors of risk to relapse and disability worsening at follow-up, respectively.

Conclusion: DMT discontinuation did not seem to influence clinical outcome, equating with the perceived limited effect of continued immunomodulation on older stable and/or progressive patients.

Keywords: Disease Modifying therapy discontinuation; Immunosenescence; Multiple sclerosis.