Mylan scores multiple sclerosis patent win over Biogen

Mylan has succeeded in having a key  Biogen patent covering multiple sclerosis (MS) drug Tecfidera (dimethyl fumarate) invalidated by a US federal court.

The ruling was issued Thursday, June 18, by the US District Court of the District of West Virginia.

The decision comes as a major blow to Biogen, which relied on Tecfidera for almost a third ($4.4 billion) of its 2019 sales.

In the ruling, the court found the specification of the Biogen patent to be overly broad. Mylan provided an expert witness who testified that the Biogen patent would not direct a person of ordinary skill in the art (POSA) towards a 480mg/day dose of dimethyl fumarate (DMF).

“Strikingly,” the court said, 480mg dosing is mentioned only once in three examples in the patent: “from about 240 mg to about 720 mg per day; or from about 480 mg to about 720 mg per day; or about 720 mg per day”.

The judge noted that there was more of a focus on the 720 mg per day dosage than any other, given that this was the upper limit of each of the three examples cited in the specification.

“Given the emphasis on 720mg/day of DMF, nothing in this passage teaches a POSA that a 480mg/day dose of DMF (BID) is therapeutically effective for treating MS,” the decision said.

In the absence of a clear written specification, Biogen relied on testimony from the inventor, but this was “not sufficient,” it added.

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