Written Description Requirement Affirmed, However Practical Implications Still In Question

On March 22, 2010, in Ariad Pharmaceuticals v. Eli Lilly & Co., No. 2008-1248, an en banc panel of the U.S. Court of Appeals for the Federal Circuit (Federal Circuit) reaffirmed that 35 U.S.C. § 112, first paragraph, sets forth a written description requirement that is separate from the enablement requirement. The Federal Circuit noted that the purpose of the requirement for “a description of the claimed invention allows the United States Patent and Trademark Office (PTO) to examine applications effectively; courts to understand the invention, determine compliance with the statute, and to construe the claims; and the public to understand and improve upon the invention and to avoid the claimed boundaries of the patentee’s exclusive rights.”

The case initially came before the Federal Circuit on appeal after the district court denied Lilly’s motion for judgment as a matter of law to set aside the jury’s finding that Lilly infringed Ariad’s patent and upholding the validity of the patent. The original Federal Circuit panel reversed the district court’s denial of Lilly’s motion and held that the claims of the patent were invalid for lack of written description. The Federal Circuit later vacated the panel’s decision and agreed to rehear the appeal en banc, asking the parties and patent community to provide additional briefing of two questions...