The drug has been used in Germany for 30 years for the treatment of psoriasis. It was officially approved by Germany's food and drug agency and put on the market on the market since 1994 in Germany under the name "Fumaderm®" for the treatment of psoriasis. Biogen® is the maker of both drugs. They are closely related versions of the same drug, fumaric acid, marketed under two different names. Biogen had obviously already done thorough clinical research on the interactions of fumaric acid esther or Tecfidera©. Hmmm... Sounds like the object an investigation!