Biogen faces patent loss for lucrative MS drug

Biogen's blockbuster drug Tecfidera is on the hot seat after federal patent judges ruled today that competing drug maker Mylan "demonstrated a reasonable likelihood" that one of the drug's main patents can be thrown out.

Why it matters: Biogen has faced a lot of patent challenges over Tecfidera, a pricey multiple sclerosis drug that registered $4.3 billion in sales in 2018. But if the board's final decision next year invalidates the Tecfidera patent in question, cheaper generic versions of the drug could hit the market as soon as 2021 instead of 2028.