The Relationship Between Written Description and Enablement Post-Biogen v. Mylan: Best Practices for Strengthening or Invalidating Patent Claims

September 21, 2022 10:45am

John T. Bennett
Allen & Overy LLP

Mary C. Till
Senior Legal Advisor
Office of Patent Legal Administration

U.S. Patent and Trademark Office


William A. Rakoczy
Founding Partner
Rakoczy Molino Mazzochi Siwik LLP

As demonstrated by the Federal Circuit’s recent denial of Biogen’s petition for en banc review in Biogen International GmbH et al. v. Mylan Pharmaceuticals Inc., written description and enablement requirements have perplexed patent practitioners for years. The dissent demonstrates opposing views at the Federal Circuit and among the bar as to §112 and signals that the Supreme Court may grant cert.

  • Reviewing Biogen International GMBH v. Mylan Pharmaceuticals Inc. Appeal No. 20-1933, where the Federal Circuit affirmed invalidity of a method of treatment patent for lack of written description
  • Appreciating the importance of inventor testimony and the impact of post-filing clinical data
  • When can witness admissions strengthen a written description invalidity defense?
  • Identifying when to divide your opponent’s testimony between IPR proceedings and district court litigation
  • Analyzing litigation insights that inform patent drafting application strategies