Second-generation disease-modifying treatments (DMTs), used to reduce the risk for relapse in multiple sclerosis, have been shown to significantly increase risk for infection, according to a study recently published in the Journal of Neurology, Neurosurgery, and Psychiatry.
Researchers followed 6793 patients with multiple sclerosis for a mean of 8.5 years, out of whom 1716 were treated with DMTs. Exposure to glatiramer acetate and beta-interferon, 2 first-generation DMTs, did not correlate with an increased risk for infection compared with no DMT (adjusted hazard ratio [aHR], 0.96; 95% CI 0.89 to 1.02), with the same outcome for separate assessment. However, second-generation DMTs natalizumab and oral DMT correlated with a significant increase in risk for infection (aHR, 1.47; 95% CI, 1.16-1.85). Natalizumab showed a much stronger individual association (aHR, 1.59; 95% CI, 1.19-2.11) than oral DMTs (aHR, 1.17; 95% CI, 0.88-1.56).
This cohort study involved identifying multiple sclerosis cases via administrative data on the population from British Columbia, Canada. Researchers tracked individual cases from the patient’s first demyelinating event, starting between 1996 and 2013, until the study ended in December 2013 or the patient either died or left the country. Researchers reported hazard ratios adjusted for sex, index year, age, socioeconomic status, and comorbidity count when assessing links between exposure to DMT and reports of infection, which they performed with recurrent time-to-events models.
Researchers conclude that “[exposure] to first-generation DMTs was not associated with an altered infection risk. However, exposure to the second-generation DMTs was, with natalizumab associated with a 59% increased risk of an infection-related physician claim. Continued pharmacovigilance is warranted, including an investigation of the DMT-associated infection burden on patient outcomes.”
Wijnands JMA, Zhu F, Kingwell E, et al. Disease-modifying drugs for multiple sclerosis and infection risk: a cohort study [published online March 30, 2018]. J Neurol Neurosurg Psychiatry. doi: 10.1136/jnnp-2017-317493