Ariad v. Eli Lilly: The Separate Written Description Requirement Under Section 112

In Ariad Pharmaceuticals v. Eli Lilly & Co. 598 F.3d 1336 (2010), an en banc panel of the Federal Circuit reaffirmed that paragraph 1 of 35 U.S.C. § 112, contains a written description requirement that is separate from the “enablement” requirement, and emphasized that “possession as shown in the disclosure” is the standard for determining whether the written description requirement has been met. 

According to the court, written description of the invention plays a vital role in curtailing claims that do not require undue experimentation to make and use, and thus satisfy enablement, but that have not been invented, and thus cannot be described. The written description requirement also ensures that when a patent claims a genus by its function or result, the specification recites sufficient materials to accomplish that function.

Accordingly, the Federal Circuit concluded that the purpose of the written description requirement is to ensure that the scope of the right to exclude, as set forth in the claims, does not overreach the scope of the inventor’s contribution to the field of art as described in the patent specification. It is part of the quid pro quo of the patent grant and ensures that the public receives a meaningful disclosure in exchange for being excluded from practicing an invention for a period of time.

Turning to the subject matter of the appeal, the Federal Circuit reversed the District Court’s denial of JMOL, holding that the asserted claims of U.S. Patent No. 6,410,516 are invalid for failure to meet the statutory written description requirement and no reasonable jury could have found for Ariad based on the facts adduced at trial.