Relapse Rate and MRI Activity in Young Adult Patients With Multiple Sclerosis: A Post Hoc Analysis of Phase 3 Fingolimod Trials

BACKGROUND: Disease activity differs in young patients with multiple sclerosis (MS) compared with the overall adult MS population. OBJECTIVE: The objective of this paper is to evaluate the effect of fingolimod 0.5 mg on disease activity in young adults with MS from three randomized, double-blind Phase 3 trials. METHODS: Annualized relapse rate (ARR), number of new/newly enlarging T2 lesions (neT2), and no evidence of disease activity (NEDA-3) were estimated in the intent-to-treat population at age 20 (youngest) and 30 (young) and compared to the overall population. Models used included a negative binomial regression (ARR/neT2) and a logistic regression (NEDA), with age at baseline as a continuous covariate. RESULTS: ARRs were higher in younger patients (all p < 0.05), and significantly reduced with fingolimod versus placebo or interferon beta-1a (IFN β-1a), with the percentage reduction inversely proportional to age. Fingolimod was significantly associated with a lower number of neT2 lesions versus placebo/IFN in all age groups except versus IFN in the youngest patients. Regardless of age, fingolimod-treated patients were more likely to achieve NEDA-3 versus placebo/IFN β-1a, with strongest benefits in the youngest patients (all p < 0.05). CONCLUSIONS: Young adults show higher levels of MS disease activity, and may particularly benefit from fingolimod treatment compared with the overall study population.