Addressing the written description requirement under 35 USC § 112, the US Court of Appeals for the Federal Circuit found that an international patent application had sufficient written description to act as a priority document rather than an invalidating obviousness reference. Hologic, Inc. v. Smith & Nephew, Inc., Case No. 17-1389 (Fed. Cir., Mar. 14, 2018) (Stoll, J).

Smith & Nephew owns a patent directed to an endoscope and has claims reciting a “permanently affixed light guide” in one of two channels. The patent claims priority to an earlier-filed Patent Cooperation Treaty (PCT) application by the same inventor and with a nearly identical specification. During the national stage examination, the specification of the application was amended to state that “[a] connection . . . for a light source is also present, for connection to a light guide, such as a fibre optics bundle which provides for lighting at the end of lens” in response to an objection for inadequate disclosure. 

After the application issued, Hologic filed a request for inter partes re-examination of the patent. During re-examination, the examiner found that the patent could not claim priority to the international application because the international application did not provide adequate written description for the broad genus of “light guides.” The examiner determined that the phrase “fibre optics bundle” alone did not provide adequate written description. The examiner found that without adequate written description in the international application, the effective priority date of the patent was well after the publication of the international application. Therefore, the international application publication was prior art to the claims of the patent under pre-America Invents Act § 102(b), resulting in rejection of the re-examined claims of the patent.

Smith & Nephew appealed to the Patent Trial and Appeal Board (PTAB), which reversed the examiner, finding that the earlier-filed PCT application provided sufficient written description support for the claimed light guide, therefore entitling the patent to the priority date of the PCT application. Hologic appealed to the Federal Circuit.

On appeal, the Federal Circuit affirmed the PTAB’s decision. The Court found that the specification of the earlier-filed PCT application supported the PTAB’s finding that the PCT application contemplated a distinct channel for light or viewing, separate from cutting tools. Based on this description, the Court found that substantial evidence supported the PTAB’s conclusion that a person of ordinary skill, reviewing the PCT figures and specification, would have understood that the inventor had possession of a light guide affixed in the “first channel.”

Practice Note: It remains good practice to include generic support, at least as an example, when drafting patent specifications. Practitioners should also ensure that claim terms, including in child applications, are fully supported in the specification of relevant priority documents.