Comparative effectiveness of cladribine tablets versus fingolimod in the treatment of highly active multiple sclerosis: A real-world study

Background: Cladribine tablets and fingolimod have similar marketing authorisations in Europe for the treatment of patients with highly active relapsing multiple sclerosis (HA-RMS). In the absence of direct head-to-head studies, real-world data are important to assess the comparative effectiveness of these oral disease-modifying therapies (DMTs). The primary objective of the present study was to compare relapse rates between patients who received either cladribine tablets or fingolimod.Methods: This multicentre retrospective study conducted in the United Kingdom and Germany assessed non inferiority in relapse rates of cladribine tablets versus fingolimod in HA-RMS patients over a 12-month period. Eligible patients who initiated treatment with cladribine tablets or fingolimod at least 12 months prior to the screening date were sampled consecutively until the target sample size was reached. Patients were censored at discontinuation of study treatment, commencement of another DMT, death, loss to follow-up, or at 12 months post-baseline, whichever happened earliest. The primary analytic timeframe for physician-confirmed relapse outcomes was the study effectiveness period (nine months of follow-up after an initial 12 weeks of treatment). Propensity score analysis was applied based on the inverse probability of treatment weighting approach.Results: The primary analytic cohort consisted of 1,095 HA-RMS patients: 610 (55.7%) receiving cladribine tablets and 485 (44.3%) receiving fingolimod. Fewer patients discontinued cladribine tablets and/or switched to another DMT compared with fingolimod (0.2% versus 3.5%, respectively). The primary endpoint, adjusted annualised relapse rate (ARR), was 0.10 (95% confidence interval [CI]: 0.07-0.14) for cladribine tablets and 0.14 (95% CI: 0.10-0.20) for fingolimod. The adjusted ARR ratio of cladribine tablets versus fingolimod was 0.68 (95% CI: 0.42-1.11). Given the entire 95% CI was less than the non-inferiority margin of 1.2, cladribine tablets was non-inferior to fingolimod.Conclusions: In this real-world retrospective cohort study, cladribine tablets demonstrated comparable effectiveness to fingolimod at one year following treatment initiation. The full treatment dosage of cladribine tablets is completed over two years and so these results may be conservative.