Mylan scores as District Court rules against Biogen in patent dispute

The US District Court for the Northern District of West Virginia has invalidated biotech major Biogen's (Nasdaq: BIIB) Tecfidera (dimethyl fumarate) patent, US Patent No 8,399,514, for lack of written description, Netherlands-headquartered generics firm Mylan (Nasdaq: MYL) announced late yesterday, reversing what had been a string of past victories over this patent for Biogen.

Following the news, shares of Biogen, for whom Tecfidera is a top-selling drug with 2019 sales of $4.43 billion (39% of its total product sales), closed down 7.5% at $260.30, while Mylan rose 2.25% by close and a further 2.3% to $16.70 after-hours.

This latest decision is in contrast to a February ruling, when the US Patent and Trademark Office (USPTO), the Patent Trial and Appeal Board, decided that Mylan had not been able to demonstrate satisfactorily that certain claims were unpatentable.