In Ariad Pharmaceutical v. Eli Lilly, 2008-1248, the en banc Court of Appeals for the Federal Circuit (CAFC) in a 9-2 decision reaffirmed the existence of an independent written description requirement, separate from enablement, in 35 U.S.C. § 112, ¶1 (first paragraph).

Ariad Pharmaceuticals and its research partners (collectively, “Ariad”) brought suit against Eli Lilly (“Lilly”) alleging infringement of U.S. Patent No. 6,410,516 (“the ’516 patent”), covering methods to regulate the activity of protein called NF-kB that regulates gene activity. After a jury’s finding of infringement at trial, the case was appealed to a panel of the CAFC which found the claims at issue invalid for lack of written description in Ariad Pharms., Inc. v. Eli Lilly & Co., 560 F.3d 1366 (Fed. Cir. 2009). Ariad petitioned for a rehearing by the CAFC en banc, which was granted to address the lingering controversy regarding the existence of an independent written description requirement in § 112, ¶1. Continue Reading