Safety of pathogenetic therapy for multiple sclerosis during the COVID-19 pandemic

The safety of pathogenetic therapy for multiple sclerosis (MS) is a crucial aspect of the therapeutic strategy during the COVID-19 pandemic. Based on our own data, obtained during the study of MS pathogenesis and safety analysis of MS disease-modifying therapies (DMTs), we hereby suggest a classification of DMTs side effects, based on their type, development, and direction of action. There is a need to thoroughly analyse adverse events caused by pathogenetic therapy, with a balanced assessment of the direct vs. adverse effects of immunosuppressive drugs. Based on available literature, in the article, data on the effect of DMTs with various mechanisms of action on severe coronavirus infection are systematized. Interferon- and glatiramer acetate are the safest drugs to use during the COVID-19 pandemic. Teriflunomide, dimethyl fumarate, natalizumab, ocrelizumab, fingolimod, alemtuzumab, and cladribine should be used with caution. Drugs with a minor systemic immunosuppressant effect (e.g. natalizumab) and selective immunosuppressants (e.g. ocrelizumab) are safer than drugs that cause non-selective depletion of T and B cells. It must be stressed that the risk of MS exacerbation and progression due to untimely prescription or cessation of pathogenetic therapy can significantly exceed the potential risk of COVID-19. Long-term safety monitoring is required for DMTs during the COVID-19 pandemic and when the epidemiological situation stabilizes.