Long-term real-world evidence for sustained clinical benefits of fingolimod following switch from natalizumab

Background: The risk of progressive multifocal leukoencephalopathy limits the duration over which patients can receive natalizumab before requiring a switch to other therapies such as fingolimod. To date, no studies have assessed the long-term real-world effectiveness and safety of fingolimod following a switch from natalizumab. We aimed to investigate the benefit-risk profile of fingolimod over 48 months in patients switching from natalizumab, and the impact of washout duration after natalizumab discontinuation on outcomes during fingolimod treatment. Methods: This analysis used data from PANGAEA, an ongoing German multicenter, prospective, non-interventional, observational study. In total, 3912 patients were included: 530 had switched from natalizumab (natalizumab subpopulation), and a reference population of 3382 had switched from other treatments or were treatment-naive (non-natalizumab subpopulation). The natalizumab subpopulation was stratified by washout duration (30-89 days, 90-149 days, and >= 150 days) prior to fingolimod initiation. Results: In the natalizumab subpopulation over 48 months of fingolimod treatment, 58.2% (n = 227/390) of patients remained on fingolimod. Over this period, mean annualized relapse rates (ARRs) and proportions of patients who relapsed were similar across washout durations, and ranged from 0.455 (95% confidence interval [CI]: 0.363-0.571) to 0.546 (95% CI: 0.446-0.669) and 54.1% (n = 92/170) to 60.2% (n = 127/211), respectively. Overall, 17.1% (n = 36/211) had 6-month confirmed disability worsening. In the non-natalizumab subpopulation, ARR was 0.300, 40.9% (n = 1325/3237) of patients relapsed, and a similar proportion to the natalizumab subpopulation had 6-month disability worsening (16.6% [n = 232/1394]). In both subpopulations, the safety profile of fingolimod was consistent with that observed in randomized controlled trials. Conclusions: In patients discontinuing natalizumab, fingolimod has a favorable benefit-risk profile over 48 months. These findings also suggest using a short washout following natalizumab discontinuation, consistent with guidelines and current clinical practice in Germany.