AMENDING CLAIMS AND ADDING INVENTOR TO CLAIM NEW ASPECT OF INVENTION, WITHOUT AMENDING SPECIFICATION, RESULTS IN JUDGMENT OF INVALIDITY FOR LACK OF WRITTEN DESCRIPTION.

Case Name: Biogen Int’l GmbH v. Mylan Pharms. Inc., No. 1:17-cv-116, 2020 WL 3317105 (N.D.W.V. June 18, 2020) (Keeley, J.)

Drug Product and Patent(s)-in-Suit: Tecfidera® (dimethyl fumarate); U.S. Patent No. 8,399,514 (“the ’514 patent”)

Nature of the Case and Issue(s) Presented: The ’514 patent claimed methods of treating multiple sclerosis through the administration of 480 mg of dimethyl fumarate (“DMF”) and/or monomethyl fumarate (“MMF”). DMF was the active ingredient in Biogen’s Tecfidera product. Mylan filed an ANDA under Paragraph IV of the Hatch-Waxman Act to market a generic bioequivalent and to certify that the ’514 patent was invalid or not infringed. As a result, Biogen brought a patent infringement action against Mylan in the Northern District of West Virginia. Through a parallel IPR proceeding, the PTAB found that Mylan failed to prove that the ’514 patent was obvious. After the parties entered into various stpulations, the only remaining issue at trial was whether the asserted claims were invalid for lack of written description pursuant to 35 U.S.C. § 112(a). The court ruled in favor of Mylan.

Why Mylan Prevailed: Mylan relied on the prosecution history of the ’514 patent to argue that the invention claimed in the ’514 patent (a method for treating MS with a 480 mg/day dose of DMF) was not the invention described in the originally-filed specification. The original claims of the ’514 patent claimed methods to identify compounds that affected a neurological pathway. After receiving clinical trial data in 2011 that showed a 480 mg/day dose of DMF could be used to treat MS, Biogen twice amended its patent application to change the title and claims and to add an inventor. But to maintain its 2007 priority date, Biogen did not amend the specification. Mylan argued that as a result of Biogen’s omission, the ’514 patent was invalid for failure to meet the written description requirement as the specification failed to describe the claimed invention, and failed to teach the invention as a person of ordinary skill in the art would not have understood that a 480 mg/day dose of DMF would effectively treat MS. The court agreed with Mylan, finding that Biogen attempted to satisfy the written description requirement by selecting specific words from the specification corresponding to the different elements of its invention, thus failing to adequately describe the invention. The court noted that the methods in the specification describing the administration of DMF and MMF were overly broad, stating that they “broadly describe[] treating neurological diseases with a therapeutically effective amount of DMF; MS is merely one such disease ‘among a slew of competing possibilities.’” The broad nature of the claims were further emphasized in light of the numerous other neurological diseases listed in the ’514 patent, which supported the court’s finding that there was no sufficient description in the ’514 patent that would teach a person of ordinary skill in the art how to treat MS with a daily dosage of DMF or MF.