Full Federal Circuit Holds Written Description and Enablement Are Separate Requirements

The U.S. Court of Appeals for the Federal Circuit recently issued an en banc decision in Ariad Pharmaceuticals Inc. v. Eli Lilly and Co. upholding an earlier ruling that patent applications must contain a specific “written description” of the claimed invention in addition to enabling language explaining how to make and use the invention. Because the written-description mandate requires applicants to provide greater detail about what the invention does, it can reduce the scope of patent protection. The March 22, 2010 decision also upheld the court’s 2009 ruling that Ariad’s patent claims were invalid because they failed to meet the written-description requirement. Finnegan partner Charles Lipsey argued the case for Eli Lilly.