Multiple Sclerosis, Disease-Modifying Therapies, and Infections

Area of Science:

• Neurology
• Infectious Disease Epidemiology
• Pharmacovigilance

Background:

• Increasing use of highly effective multiple sclerosis (MS) disease-modifying therapies (DMTs).
• Limited understanding of real-world infection risks associated with various MS DMTs.
• Need to differentiate risks attributable to DMTs versus MS itself or other factors.

Purpose of the Study:

• To compare the real-world risk of outpatient and serious infections across different MS DMTs.
• To assess whether infection risks are linked to specific DMTs, the presence of MS, or other patient factors.

Main Methods:

• Retrospective cohort study utilizing electronic health records from Kaiser Permanente Southern California (2008-2020).
• Inclusion of MS patients and matched non-MS controls.
• Analysis of MS treatments, outpatient and serious infections, and covariates using Cox and Poisson regression.

Main Results:

• Patients with MS exhibited higher risks of both outpatient and serious infections compared to controls.
• Specific DMTs showed varying infection risks: Rituximab and fingolimod increased outpatient infection risk, while rituximab and natalizumab increased serious infection risk compared to interferon-beta/glatiramer acetate (IFN/GLAT).
• Fingolimod was uniquely associated with outpatient herpetic infections; comorbidities and prior hospitalizations independently raised serious infection risk.

Conclusions:

• Patients with MS have an elevated risk of infections, influenced by specific DMTs.
• Risk mitigation strategies include optimizing bladder care, managing comorbidities, vaccination, and careful consideration of DMTs in high-risk patients.
• Findings highlight the need for personalized risk assessment when selecting MS DMTs.