COVID-19 occurring during Natalizumab treatment: a case report in a patient with extended interval dosing approach

Background: The novel Coronavirus SARS-CoV-2, which was identi fied after a recent outbreak in Wuhan, China, in December 2019, has generated a global pandemic impacting over 200 countries around the world. Recent reports suggest that ACE2, which is the target protein to invade the host, has a ubiquitous presence in human organs, including lung parenchyma, gastrointestinal tract, nasal mucosa, renal and urinary tract, airway epi- thelia, lymphoid tissues, reproductive organs, vascular endothelium and neurons. In this scenario, neurologists are particularly involved into considering even more speci fic therapeutic strategies according to the available data during the pandemic. In particular, MS patients are usually receiving disease -modifying therapies (DMTs) with immunosuppressant or immunomodulatory e ffects, which increase the risk of infections and morbidity, compared with the general population. Development of PML or other serious opportunistic infections during treatment with natalizumab forces to consider whether de -risking strategies are needed in this particular context and how to manage a high -e fficacy treatment. Methods: In this paper we report on a patient treated with natalizumab for relapsing MS who developed COVID- 19 and recovered in a few days without complications. Results: After recovery natalizumab has been administered in the window of the extended interval dosing (EID), without reporting any worsening or new symptoms. Discussion: This case supports the opportunity to avoid discontinuing or delaying the retreatment over 8 weeks in patients recovered from a recent COVID-19.