Jiwon Oh, MD, PhD: A number of groups have published different guidelines regarding disease-modifying treatments and COVID-19. The National Multiple Sclerosis Society [NMSS] is 1 organization that has published clear and easy-to-follow guidelines. Many other organizations around the world have published guidelines that are very similar to the NMSS.
What the NMSS does is it divides the disease-modifying treatments that we typically use in people living with MS [multiple sclerosis] into 3 categories. The first category includes immunomodulators that generally do not suppress the immune system. The medications that fall into that category are the interferon beta agents as well as glatiramer acetate and natalizumab. Natalizumab blocks trafficking of lymphocytes into the central nervous system, so technically it does not reduce peripheral immunity that is thought to be important in preventing the acquisition of coronavirus.
The second category that the NMSS divides disease-modifying treatments into is immunomodulators that restrict the ability of the immune system to respond to an infection. Many of the MS disease-modifying treatments fall into this category. They include the oral therapies, like dimethyl fumarate, and variations of dimethyl fumarate. Fingolimod, siponimod, as well as teriflunomide are included here. These are medications that many of our patients are on, and we do know that they slightly decrease the immune system, but it’s not clear whether it dramatically changes one’s ability to respond to infections like COVID-19 [coronavirus disease 2019].
Finally, the last category is immunosuppressants that deplete lymphocytes. The medications that fall into this category are alemtuzumab, cladribine, mitoxantrone, and ocrelizumab. In some places that use it, rituximab is also included. We are a bit more worried about these medications because we consider them to be highly potent. These are ones that dramatically—or sometimes to a lesser extent—deplete lymphocytes, which we know are key to one’s ability to fight diseases such as COVID-19.
We do get slightly more concerned when patients are on 1 of these medications. However, again, based on the data that have been accumulated thus far, even in many patients around the world who have acquired COVID-19 and have been on 1 of these lymphocyte-depleting agents, there does not seem to be a strong signal of being at extremely high risk for developing COVID-19—related complications.