Multiple sclerosis disease-modifying therapies: mechanisms of action
How MS disease-modifying drugs work, from interferon and glatiramer to teriflunomide, fumarates, S1P modulators, cladribine, natalizumab, anti-CD20 and alemtuzumab, and how each mechanism predicts its adverse effects, monitoring and washout.
Tier 2Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Relapsing MS is driven by autoreactive T cells and B cells crossing the blood-brain barrier. Disease-modifying therapies (DMTs) reduce lymphocyte activation, numbers or entry to the CNS.
- They reduce relapses and new MRI lesions. Progressive disease, driven by compartmentalised CNS inflammation and neurodegeneration, responds much less.
- Each mechanism predicts the toxicity: block lymphocyte trafficking and you get PML or rebound; deplete cells and you get infection, hepatitis B reactivation or reconstitution autoimmunity.
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Sources
- Therapeutic Guidelines: Neurology (Multiple sclerosis)AU/NZTherapeutic Guidelines Ltd, 2026
- MS Australia treatment and disease-modifying therapy informationAU/NZMS Australia, 2026
- ECTRIMS/EAN guideline on the pharmacological treatment of people with multiple sclerosisMultiple Sclerosis Journal (Montalban X et al., 2018;24:96-120), 2018
- Risk of natalizumab-associated progressive multifocal leukoencephalopathy in patients with multiple sclerosis: a retrospective analysis of data from four clinical studiesLancet Neurology (Ho PR et al., 2017;16:925-33), 2017
- Risk of natalizumab-associated PML in patients with MS is reduced with extended interval dosingNeurology (Ryerson LZ et al., 2019;93:e1452-62), 2019
- Rapid review of PBS medicines for relapsing-remitting multiple sclerosisAU/NZAustralian Government, Pharmaceutical Benefits Scheme, 2026
- Tolebrutinib in nonrelapsing secondary progressive multiple sclerosis (HERCULES)New England Journal of Medicine (Fox RJ et al., 2025), 2025
- Tolebrutinib receives FDA complete response letter for nrSPMSPharmacy Times, 2026
- Efficacy of natalizumab every 6 weeks versus every 4 weeks in relapsing-remitting multiple sclerosis (NOVA)Lancet Neurology (Foley JF et al., 2022;21:608-19), 2022
- Thyroid disorders induced by alemtuzumab in multiple sclerosis: a systematic review and meta-analysisJournal of Endocrinological Investigation (Scappaticcio L et al., 2020), 2020
- Last updated
- 14 November 2026
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