Interferon Beta Mechanism and Clinical Efficacy in Multiple Sclerosis

Mechanism of Action and Clinical Effects

• The American Academy of Neurology suggests that IFN-β likely involves immunomodulatory effects, including enhancement of suppressor T cell activity, reduction of pro-inflammatory cytokine production, and inhibition of lymphocyte trafficking into the central nervous system, in patients with multiple sclerosis 1
• Brain volume loss is associated with cognitive impairment, fatigue, and disability progression in MS patients, and IFN-β may have a positive effect on brain atrophy, as shown in the ETOMS trial 1
• The European Committee for Treatment and Research in Multiple Sclerosis recommends considering the pseudoatrophy effect when evaluating treatment response, as it can cause excessive decrease in brain volume within the first 6-12 months of treatment 1

Brain Atrophy Effects and Adverse Events

• The National Multiple Sclerosis Society notes that the ETOMS trial provided clear evidence for a positive effect of IFN-β on brain atrophy, with a 30% reduction in brain atrophy in patients with clinically isolated syndromes compared to placebo 2
• Common adverse events of IFN-β treatment include fatigue, depression, and thrombocytopenia, with a strength of evidence rated as high for these adverse events 1, 3
• The American College of Neurology recommends monitoring treatment response by evaluating clinical relapses, MRI activity, and disability progression, while being aware that brain volume changes may show initial worsening due to pseudoatrophy before stabilizing 2