CAFC Affirms the Importance of Written Description in a Provisional Patent Application

On March 24, 2025, in In re Riggs, No. 22-1945, the Court of Appeals for the Federal Circuit (CAFC) addressed when the filing date of a provisional application can be relied on under 35 U.S.C. § 102(e) to support a rejection of a later-filed application. This opinion offers clarity on the importance of written descriptions in provisional patent applications for Patent Owners as well as Petitioners seeking to challenge a patent in a post-grant proceeding.

In re Riggs centers on U.S. Patent Application No. 11/005,678 (“the ‘678 application”), which relates to integrated logistics systems and methods for managing the shipments of goods by various carriers across different modes of transportation. The ‘678 application claims priority to a provisional application filed July 28, 2000. The reference cited against the ‘678 application was U.S. Patent Publication No. 2002/0049622 of Lettich (“Lettich”), which claims priority to a provisional application filed April 27, 2000. Under section 102(e), “[a] person shall be entitled to a patent unless (e) the invention was described in (1) an application for patent, published under section 122(b), by another filed in the United States before the invention by the applicant for patent or (2) a patent granted on an application for patent by another filed in the United States before the invention by the applicant for patent.” Because Lettich’s provisional application filing date predates that of the ‘678 application, the Examiner cited Lettich as 102(e) prior art against the claims of the ‘678 application.

An appeal was filed to the Patent Trial and Appeal Board (PTAB) challenging the Examiner’s rejection of the claims of the ‘678 application, arguing that Lettich should not be considered prior art. In a 2016 decision, the PTAB agreed with the Applicants and reversed the Examiner. However, the Examiner recognized that the PTAB had applied an incorrect version of 35 U.S.C. § 102(e) in determining Lettich's status as prior art and filed a Request for Rehearing. In the Rehearing Decision, the PTAB amended its initial ruling and affirmed that Lettich qualifies as prior art. Consequently, the Examiner’s anticipation and obviousness rejections based on Lettich were upheld. This PTAB decision was subsequently appealed, but while the appeal was pending, the Federal Circuit granted a motion by the U.S. Patent and Trademark Office (USPTO) to vacate and remand the case, allowing the PTAB to address additional arguments in light of Federal Circuit decisions in Dynamic Drinkware, LLC v. National Graphics, Inc., 800 F.3d 1375 (Fed. Cir. 2015) and Amgen Inc. v. Sanofi, 872 F.3d 1367 (Fed. Cir. 2017). On remand, the PTAB reaffirmed its previous findings, concluding that Lettich’s claim 1 was adequately supported by the provisional filing, therefore qualifying Lettich as prior art under 35 U.S.C. § 102(e). The decision was appealed to the Federal Circuit.

The Federal Circuit determined that the PTAB's analysis of whether Lettich qualifies as prior art under 35 U.S.C. § 102(e) was incomplete. The Court observed that there was no dispute over whether Lettich is a published nonprovisional application that properly claims priority to the Lettich Provisional Application. The key issue in determining whether Lettich qualifies as prior art under 35 U.S.C. § 102(e) is whether it is entitled to the priority date of the provisional application.

Both the Examiner and the PTAB relied on Dynamic Drinkware, Amgen, and MPEP § 2136.03 to support the conclusion that “at least one claim in the Lettich Application Publication must find written description support in the Lettich Provisional Application in order for the Lettich Application Publication to be prior art against the instant claims.” While the PTAB identified support for each limitation of claim 1 of Lettich in the corresponding provisional application, the Federal Circuit found that this test is insufficient when the Examiner demonstrates support for only one claim but then relies on other sections of the specification to support the rejection.

In both Dynamic Drinkware and Amgen, the Court decision did not address the specific issue of whether the content of the prior art relied upon also required written description support in the provisional application. However, the PTAB seemed to interpret Dynamic Drinkware and Amgen as meaning that if a single claim in the published application or patent is adequately supported by the written description of a corresponding provisional application, then the filing date of the provisional application applies carte blanche to the published application or patent, regardless of whether the cited portions of the published application were adequately supported by the corresponding provisional application.

The Court disagreed with the PTAB’s interpretation, explaining that a reference does not automatically constitute prior art as of its provisional application’s filing date solely because a particular claim is adequately supported by the provisional application. Rather, the provisional application must provide written description support for the particular portions of the prior art that are being relied upon in the rejection. The Court vacated the PTAB’s decision as to whether Lettich qualifies as prior art under 35 U.S.C. § 102(e) and remanded the case.

The In re Riggs opinion is important to consider at every stage of the patent lifecycle, from drafting and prosecution, to post-grant proceedings. The Court has clarified that the priority date of a provisional application applies to all that it teaches, underscoring the importance of filing a comprehensive provisional patent application to ensure a Patent Owner fully benefits from the priority date. Provisional applications that are incomplete or lacking in detail may risk the priority date and hinder the ability to protect the invention. For prosecution, In re Riggs serves as a reminder to verify that any cited prior art reference is entitled to its priority date when that date is being used to establish the reference as prior art. Both Patent Owners and Challengers must also consider this ruling during post-grant proceedings. Petitioners seeking to initiate such proceedings must ensure that any cited reference is properly supported by the provisional application when relying on the provisional filing date, while Patent Owners should consider this decision in determining whether to contest challenges that depend on a provisional filing date.

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