Is there a role for off-label high-efficacy disease-modifying drugs in progressive multiple sclerosis? A network...

Ocrelizumab and siponimod are the two on-label drugs used for progressive forms of multiple sclerosis (PMS). However, many patients with PMS do not have access to these high-efficacy disease-modifying drugs (DMDs). Off-label prescription of other high-efficacy DMDs (fingolimod, rituximab and natalizumab) may be a strategy to improve access to immunotherapy for these patients. We aim to compare on-label and off-label high-efficacy drugs for their effect on disability progression in PMS. In December 2021, we searched MEDLINE (PubMed), Embase, Cochrane Central and Scopus databases for randomized clinical trials involving patients with PMS. High-efficacy drugs were considered as intervention and placebos as comparison. The outcome contemplated was risk of Expanded Disability Severity Scale (EDSS) progression at 2 years. A network meta-analysis was performed to compare the relative risk of EDSS progression at 2 years compared with placebo in on-label and off-label drugs. We included five studies with 4526 patients. The median EDSS progression at 2 years in patients that received any immunotherapy was 30%, compared with 35% in placebo groups. Overall, the risk of bias of individual studies was low. Network analysis revealed overlapping confidence intervals in off-label drugs (CI95% 0.51-2.16) versus ocrelizumab (reference) and off-label drugs (CI 95% 0.53-1.96) versus siponimod (reference), suggesting similar efficacy. The same result was found even after excluding studies with the risk of publication bias. Off-label high efficacy immunotherapy in PMS has biological plausibility and presented similar effectiveness to on-label DMDs in this network meta-analysis. The use of fingolimod, rituximab or natalizumab may be a strategy that reduces costs and improves access to immunotherapy for patients with PMS.