Biogen rehearing denied: Is SCOTUS the next step?

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White & Case Tech Newsflash

On March 16, 2022, the Court of Appeals for the Federal Circuit denied Biogen’s petition for en banc review in Biogen International GmbH et al. v. Mylan Pharmaceuticals Inc.1 ("Petition Denial"), in which a Federal Circuit majority panel previously held that Biogen’s patent directed to a method of treating multiple sclerosis was invalid for lack of written description. Judge Lourie, Judge Newman, and Chief Judge Moore dissented from the Court’s denial of en banc review. The dissent is significant and may provide support for a petition for writ of certiorari to the Supreme Court.


How Biogen got here

Biogen’s patent covers its multiple sclerosis drug, Tecfidera®. After prevailing at the district court on invalidity for lack of written description, Mylan launched a generic version of Tecfidera® in August 2020. The claims at issue in Biogen’s patent recite a method of administering a therapeutically effective amount of about 480 mg of dimethyl fumarate ("DMF") per day to treat multiple sclerosis.  

Claim 1 of the patent-in-suit is as follows:

A method of treating a subject in need of treatment for multiple sclerosis comprising orally administering to the subject in need thereof a pharmaceutical composition consisting essentially of 

  • (a) a therapeutically effective amount of dimethyl fumarate, monomethyl fumarate, or a combination thereof, and 
  • (b) one or more pharmaceutically acceptable excipients, wherein the therapeutically effective amount of dimethyl fumarate, monomethyl fumarate, or a combination thereof is about 480 mg per day.

The patent specification recites a range of effective doses of DMF, including "from about 480 mg to about 720 mg per day." In a 2-1 decision, the Federal Circuit majority panel held that "the district court did not clearly err in finding that a skilled artisan would not have recognized, based on the single passing reference to a DMF480 dose in the disclosure, that DMF480 would have been efficacious in the treatment of MS, particularly because the specification’s only reference to DMF480 was part of a wide DMF dosage range and not listed as an independent therapeutically efficacious dose."2 Judge Reyna authored the majority panel decision, and Judge O’Malley filed a dissenting opinion.


Deep dive into the dissent

Biogen subsequently sought en banc review, which the Court denied on March 16, 2022, by a 6-3 vote. The dissent, authored by Judge Lourie, described the panel decision as an "outlier" and remarked, "this case, in which every claim limitation is expressly described in the disclosure of the patent specification, is at the farthest end of the spectrum of cases where written description has not been found."3

  • The dissent first examined whether the disclosure of multiple sclerosis among several other neurological disorders in the specification provided adequate written description for the claimed method. The dissent concluded that because the specification expressly described the claimed species, the disclosure was sufficient and the majority panel’s emphasis on unclaimed disclosures in the specification was erroneous.4 ("In this case, where the claimed species—i.e., ‘multiple sclerosis’ within the genus ‘neurological diseases’—is expressly described in the specification, the written description requirement is satisfied regardless of the specification’s additional disclosure of other unclaimed neurological diseases."). 
  • The dissent also took issue with the majority panel’s emphasis on the fact that the claimed 480 mg dose is listed only once in the entire specification at the end of a range.  According to the dissent,
    "written description support for the claimed 480 mg per day dose is not undermined by the fact that it
    only appears one time in the specification or by the fact that the patent also discloses unclaimed dose
    ranges. ("The disclosure of a dose outside of the claimed range does not compel a finding that the
    asserted claims lack adequate written description."). Once is enough."
  • The dissent also suggests that the panel opinion blurs the line between written description and enablement. In particular, the dissent argued that "[b]y focusing on whether the patentee proved that 480 mg per day is an effective amount to treat multiple sclerosis—as distinct from whether the ’514 patent specification discloses that 480 mg per day is an effective amount to treat multiple sclerosis—the panel majority and the district court erroneously imported operability considerations into the written description analysis."  In the dissenting Judges’ view, written description was satisfied because the specification "expressly states that 480 mg per day is an effective amount," notwithstanding the lack of any additional evidence or data in the patent that such a dose would actually be therapeutically effective.  

The lingering question

The dissent in this case illustrates the differing views within the Federal Circuit as to the written description requirement and its relationship to enablement, and signals that the case may be a possible candidate for Supreme Court review.


1 No. 20-1933 (Fed. Cir. 2022)
2 Biogen Int’l GmbH v. Mylan Pharms., Inc., 18 F.4th 1333, 1343 (Fed. Cir. 2021).
3 Petition Denial, slip op. at 3 (Lourie, J., dissenting)
4 Id. at 8
5 Id. at 9.
6 Id. at 11 (emphasis in original)
7 Id. at 10


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