Effect of Disease‐Modifying Treatments in Japanese Patients With Multiple Sclerosis During the Coronavirus Disease 2019 Pandemic

ABSTRACT Objectives Most disease‐modifying treatments (DMTs) for patients with multiple sclerosis (PwMS) do not influence the risk and outcome of coronavirus disease (COVID‐19), except for anti‐CD20 monoclonal antibodies (ocrelizumab and rituximab). However, data on Japanese PwMS are lacking. Thus, we evaluated the risk of COVID‐19 in Japanese PwMS undergoing DMTs. Methods In this retrospective cross‐sectional study, we used the Japanese administrative database. The incidence of COVID‐19 between January 1, 2022, and December 31, 2024 was compared between PwMS who were administered different DMTs. Results In total, 61 of 1044 (5.8%) PwMS who were administered baseline treatments and 102 of 1253 (8.1%) PwMS who were administered high‐efficacy treatments had COVID‐19. The prevalence of COVID‐19 was significantly higher in PwMS receiving high‐efficacy treatments than in those receiving baseline treatments. However, this prevalence did not differ significantly among PwMS on different individual DMTs. Conclusion Although high‐efficacy therapy may increase the overall prevalence of COVID‐19, no specific DMT approved in Japan was associated with an increased prevalence of COVID‐19 among Japanese PwMS.