The early effect of induction versus continuous therapies in active multiple sclerosis: a multimodal study on the first course of cladribine versus fingolimod

Background: Induction therapies for multiple sclerosis (MS), such as cladribine (CLAD), require multiple cycles to achieve full clinical effects, and the extent of immunosuppression from a single course is unclear. Fingolimod (FINGO), administered daily, provides a rapid anti-inflammatory effect, desirable for active MS. Objectives: to compare the efficacy of the first course of CLAD versus FINGO over 12 months by analyzing clinical data, brain atrophy, retinal thinning, and diffusion MRI metrics of myelin and neuroaxonal integrity in the corpus callosum. Methods: evaluations included NEDA-3 status, percentage brain volume change (PBVC) and changes in retinal nerve fibers and MRI metrics of the corpus callosum such as Intra-Cellular Volume Fraction (ICVF) and Orientation Dispersion Index (ODI). Results: we included 65 relapsing-remitting MS patients (33 on CLAD, 32 on FINGO). After 12 months, 81.8% of CLAD patients and 71.9% of FINGO patients achieved NEDA-3 (p = 0.4). PBVC <-0.4% was observed in 41.9% of CLAD and 39.2% of FINGO patients (p = 0.9). Both drugs showed similar effects on retinal thinning and ICVF and ODI of the corpus callosum. Conclusions: A single course of cladribine has comparable efficacy to daily fingolimod treatment based on clinical, OCT and advanced MRI measures.