ABSTRACT
Immunomodulatory drugs are important to control disease activity in relapsing-remitting multiple sclerosis (MS).Anti-CD20-therapy is one of such medications. In Sweden, extensive off label prescription of rituximab (RTX) in MS hasbeen documented;it is presently prescribed for more than half of all treated MS patients. The rationale for the increasingprescription of RTX was previous data from phase II and observational studies supporting high efficacy and safety, in additionto the financial aspect. We report national data on usage of disease modifying therapies in MS patients and risk of severeCOVID-19 in association with RTX exposure within this group.The Swedish National MS Registry (SMSreg) aims to cover all patients with MS in the country, (n = approximately18,000). After COVID-19 pandemic started in Sweden, a new section was established in it to register clinical and demographicparameters in COVID-19-infected patients. Data presented in the current report were obtained from the SMSreg.A total of 85 out of approximately 6,000 RTX-treated Swedish MS patients had been hospitalized with COVID-19(as reported from the SMSreg, June 16, 2021) and adjusted analyses showed a 2–3 fold increase in a risk (OR = 2.89;p = 0.001) of hospitalization for anti-CD20 treated patients. A change of praxis was introduced in Sweden in spring2020, resulting in a majority of patients receiving RTX infusions with extended intervals in order to reduce the risk ofsevere COVID-19 infection.Current Swedish registry data suggest that exposure to RTX in MS may affect the clinical outcome of COVID-19 infection.These observations have rapidly impacted use of immunomodulatory drugs in Swedish MS patients © Iacobaeus E., Boström I., Zhukovsky Ch., Berntsson Sh.G., Landtblom A.-M., 2021