By Keelin Bielski
The Federal Circuit recently resolved a split in district courts in Ingenico Inc., v. IOENGINE, LLC, 2023-1367, holding that IPR estoppel “does not preclude a petitioner from asserting that a claimed invention was known or used by others, on sale, or in public use in district court” even if publications describing such a device could have been raised in an IPR as evidence of anticipation or obviousness. __ F.4th __, 2025 WL 1318188, at *7 (Fed. Cir. 2025).
Under the doctrine of IPR estoppel, petitioners cannot raise invalidity grounds in a district court case that they raised or could have reasonably raised during an IPR. 35 U.S.C. § 315(e)(2). Generally, IPR estoppel does not apply to device art because, under the IPR statute, a petitioner cannot use an IPR to challenge the validity of a patent claim based on the theory that the claimed invention was known or used by others, on sale, or in public use. 35 U.S.C. § 311(b). However, district courts had been split on whether device art that is materially identical to prior art in the form of patents or printed publications that were or could have been raised in an IPR. See Prolitec Inc. v. ScentAir Techs., LLC, No. 20-984-WCB, 2023 WL 8697973, at *21-23 (D. Del. Dec. 13, 2023) (collecting cases).
In the present case, prior to trial at the district court, Ingenico filed IPR petitions challenging IOENGINE’s asserted patents, which resulted in final written decisions determining that most of the challenged claims were unpatentable. Ingenico, 2025 WL 1318188, at *1. IOENGINE filed a motion in the district court to preclude Ingenico from relying on “documentation related to” a device alleged to have disclosed limitations of the claims of the asserted patents because Ingenico could have reasonably relied on such documentation during the IPR proceedings. Id. The district court held Ingenico was estopped from relying on such documentation, unless it was part of a substantively different prior art combination that could not have been raised in the IPR. Id.
During trial, the judge allowed Ingenico to rely on the documentation and additional documentation to establish that the claimed invention was known or used by others, on sale, or in public use. Id. Following a jury verdict that the asserted patents were anticipated and obvious, IOENGINE appealed, arguing that Ingenico should have been estopped from using the documentation to establish a device as prior art. Id. at *2, *5.
The Federal Circuit interpreted the meaning of the word “ground” in the IPR Estoppel statute, 35 U.S.C. § 315(e)(2), for the first time, stating that “a ground is not the prior art asserted during an IPR,” but rather a “theory of invalidity.” Id. at *6-7. And because an IPR petitioner cannot raise a ground of invalidity based on public uses or sales according to the IPR statute, “IPR estoppel does not preclude a petitioner from relying on the same patents and printed publications as evidence” for such a ground, even if those patents and printed publications were considered in an IPR petition as evidence of anticipation or obviousness based on a patent or printed publication. Id. at *7.
In view of this decision, parties who wish to challenge patent claims based on a device that was publicly known or sold can now first challenge the claims in an IPR based on patents and printed publications that describe the device, and then in the district court using the device itself, without running afoul of IPR estoppel.
