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Ariad Pharm., Inc. v. Eli Lilly & Co. - 598 F.3d 1336 (Fed. Cir. 2010)


A sufficient description of a genus for purposes of a patent requires the disclosure of either a representative number of species falling within the scope of the genus or structural features common to the members of the genus so that one of skill in the art can "visualize or recognize" the members of the genus. An adequate written description requires a precise definition, such as by structure, formula, chemical name, physical properties, or other properties, of species falling within the genus sufficient to distinguish the genus from other materials. Functional claim language can meet the written description requirement when the art has established a correlation between structure and function. But merely drawing a fence around the outer limits of a purported genus is not an adequate substitute for describing a variety of materials constituting the genus and showing that one has invented a genus and not just a species.


Plaintiff drug company filed an infringement suit against defendant competitor. A jury found for the plaintiff, and the district court denied defendant’s motion for judgment as a matter of law. The appellate court reversed. Rehearing en banc was granted on whether 35 U.S.C.S. § 112, para. 1, required a separate written description.


Did the asserted claims of the patent comply with the statutory written description requirement?




The court reaffirmed that 35 U.S.C. § 112, para. 1, contained a written description requirement separate from enablement. Section 112, para. 1, contained two separate description requirements: a written description (1) of the invention, and (2) of the manner and process of making and using the invention. Nothing dictated that adequacy be determined solely by whether the it identified the invention so as to enable one skilled in the art to make and use it. The requirement had been the law for 40 years and 35 U.S.C.S. § 132's prohibition on new matter, an examiner's instruction, did not negate the need to provide a written description.

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