The recommendations of the major countries
The various regulatory agencies in the different countries have taken very specific positions to regulate the intake of drugs for MS without risk to the patient during the period of Sars-CoV-2. The aim of the study is to summarize all the recommendations of each individual country and understand the orientation towards stopping treatments for MS. In general, no country recommends stopping treatment for MS and taking care to classify drugs based on risk (table 1 ).
Only IFNs and Glatiramer agree on all countries: INFs are safe and can also protect against the risk of covid infection. This is why they are safe treatments. The glatiramer is also considered safe, only in Italy is the position more prident. Everyone agrees to discontinue therapy or shift to IFN in the event of a covid infection. Of all the countries, only the USA gives the doctor a wide choice to understand if it is appropriate to continue the current therapy or not. The American FDA simply divided the drugs according to the risk but left the doctor the choice to understand the real risk based on the patient’s clinical picture.
Describing the remaining drugs we have that first-line drugs (teriflunomide and dimethyl fumarate) should be continued and suspended in the event of covid injection and, in Germany and Canada, also in the case of severe lymphopenia. In Italy, the position is more prudent with regard to teriflunomide and the possible shift towards interferon therapies must be assessed.
Second-line therapy with fingolimod disagrees the various nations: in Germany and Canada, continuation of therapy is recommended by carefully evaluating the risk; in Italy the suspension or shift to IFNs is assessed, while in the UK the emphasis is also placed on the danger of rebaunding the MS in case of sudden suspension.
Depletive drugs (cladribine, ocrelizumab and alemtuzumab) should always be suspended or delayed for up to 6 months. All agencies agree. Only ocrelizumab in the UK can be used if considered essential. The only exception to this class of drugs is natalizumab. NTZ is considered as safe all over the world as IFNs therapies, only in Italy there is greater caution with immediate suspension in case of positive covid patients.