In Hologic, Inc. v. Smith & Nephew Inc., No. 2017-1389 (Fed. Cir. Mar. 14, 2018), the Federal Circuit concluded that disclosure of a species provides written descriptive support for a claimed genus where the invention was in a predicable field of art, the species was a well-known member of the genus, and other members of the genus were also well known. As a result, the court affirmed the PTAB’s decision that Smith & Nephew’s PCT application (the “Emanuel PCT”) had sufficient written description to qualify as a priority document, and therefore was not prior art. In reaching this decision, the court relied heavily on the fact that the field of the invention was a predictable art.

U.S. Patent No. 8,061,359 (“the ‘359 patent”) is directed to use of a light-guided endoscope for uteral surgery. The ‘359 patent was filed on July 20, 2007, as a divisional of a U.S. national stage of International Patent Publication No. WO 99/11184 (“Emanuel PCT”). Claim 1 of the ‘359 patent, introduced in a preliminary amendment during prosecution, recites the limitation “the first channel having a light guide permanently affixed therein.” The specification of the ‘359 patent was amended during prosecution to address an objection to the drawings for not showing the “light-guide” recited in claim 1.

The ‘359 patent was later found invalid over the Emanuel PCT in an inter partes reexamination proceeding initiated by Hologic. In that proceeding, the examiner found that the Emanuel PCT lacked sufficient written description to support the ‘359 patent’s claim of priority to it. The Examiner concluded that the PCT application was, therefore, prior art to the ‘359 Patent, and he rejected claims of the ‘359 Patent for obviousness. On appeal, the PTAB reversed the examiner’s decision, concluding that the description of the species of “fibre optic bundles” was sufficient written description of a “light-guide” to support the priority claim.

The standard for assessing sufficiency of disclosure is “whether the disclosure of the [earlier] application relied upon reasonably conveys to those skilled in the art that the inventor had possession of the claimed subject matter as of the earlier filing date.” Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en banc). In determining that the disclosure was sufficient, the court agreed with the PTAB that the invention’s field was a predictable art, warranting a lower level of detail to satisfy the written description requirement. The court also noted that fiber optic bundles were well known examples of light guides and that other examples were also well known in the art.

Hologic argued that failure in Emanuel PCT to illustrate in its figures a light guide or fiber optic bundle supported a conclusion that the Emanuel PCT lack sufficient support. The court, however, concluded that “written description does not require that every claimed element be illustrated in the figures, particularly in predictable arts and where the element not depicted is conventional and not necessary for the understanding of the subject matter sought to be patented.”

Finally, in addressing Hologic’s arguments that the limitation of the light guide being permanently affixed was not supported by the disclosure, the court concluded that it was proper to look not only at intrinsic evidence, such as the patent figures, but also consider prior art patents and expert testimony that reflect the state of the art. According to the court, relying on that evidence was appropriate to determine “what the specification reasonably conveys to the skilled artisan who has knowledge of the prior art.”