Assess the impact of previous treatments on the effects of fingolimod and injectable disease-modifying therapy (iDMTs) on magnetic resonance imaging (MRI) outcomes of lesion activity as surrogate measures of disease progression.

In the USA, fingolimod is approved as first-line therapy for multiple sclerosis (MS), but is sometimes prescribed following an iDMT. PREFERMS was a 12 month, phase 4, open-label, active-controlled, multicenter study of treatment retention with fingolimod or iDMTs in patients with relapsing MS.

In PREFERMS, patients were randomized (1:1) to fingolimod 0.5 mg/day or an iDMT (interferon beta or glatiramer acetate). Treatment switch was allowed for any reason after ≥3 months, or before for efficacy or safety. MRI outcome changes from Baseline were compared at end of randomized treatment (end of study or when a patient switched from randomized treatment). Overall change in number of gadolinium-enhancing (Gd+), new Gd+, new active or new/enlarging lesions were assessed by negative binomial regression. Data are presented as mean (95% confidence interval). These post hoc analyses are for hypothesis generation.

Patients were treatment naive (n=404, 46.2%) or had received one class of iDMT (n=471, 53.8%). Irrespective of previous treatment, MRI outcomes were favorable for fingolimod vs iDMT: new Gd+ lesions (naive, 0.19 [0.1-0.3] vs 0.45 [0.2-0.7], p=0.0034; treated, 0.13 [0.0-0.2] vs 0.33 [0.1-0.6], p=0.0004), new active lesions (naive, 0.70 [0.3-1.1] vs 1.63 [0.8-2.4], p=0.0001; treated, 0.46 [0.2-0.7] vs 1.46 [0.3-2.6], p=0.0001), new/enlarging lesions (naive, 2.36 [1.5-3.2] vs 2.93 [1.9-4.0], p=0.0068; treated, 1.20 [0.7-1.7] vs 1.99 [0.9-3.1], p=0.0003) and overall change in Gd+ lesions (naive, −1.38 [−2.0 to −0.7] vs −0.80 [−1.4 to −0.2], p=0.0030; treated, −0.39 [−0.7 to −0.1] vs −0.02 [−0.3 to 0.3], p=0.0015).