Dorsey & Whitney LLP
In a precedent opinion issued on May 7, 2025 by the United States Court of Appeals, Federal Circuit, the Court of Appeals affirmed a verdict of a jury invalidating two patents due to anticipation and obviousness compared to the prior art. In this case, the key question was whether estoppel had to be applied in order to prevent certain prior art from being presented at trial. The case is Ingenico, Inc. v. IOENGINE, LLC.
Plaintiff-Appellee Ingenico filed a declaratory judgment action against Defendant-Appellant IOENGINE related to certain IOENGINE patents. Before trial, Ingenico had also commenced inter partes review (“IPR”) proceedings related to IOENGINE’s patents, resulting in final written decisions invalidating some claims of the patents.
Under 35 U.S.C. Ingenico presented evidence related to a prior art system at trial and argued the system invalidated IOENGINE patent claims because the claimed invention had been “on sale” or in “public use” under pre AIA Section 102 (b) or was “known or used” by others under pre AIA Section 102 (a). IOENGINE argued that Ingenico was not allowed to present portions of evidence related to the prior-art system because it was cumulative and substantially identical to certain printed publications which could have been raised in IPR. The Federal Circuit acknowledged that lower courts interpreted “ground” differently. In relevant part, courts have interpreted the term “ground” as referring to the specific prior art that was or reasonably could have presented during an IPR. The court held that IPR estoppel only applies to petitioner’s assertions made in district court that a claimed invention is invalid according to 35 U.S.C. The court explained that “ground” refers “to the theories of invalidity that can be used to challenge a claim made under 35 U.S.C. The court explained that “IPR estoppel does not preclude a petitioner from asserting the same prior art raised in an IPR in district court, but rather prevents a petitioner from asserting grounds that were raised or reasonably could have been raised during an IPR, such as that the claimed invention was known or used by others, on sale, or in public use.” The Federal Circuit’s ruling resolves a split between lower courts by allowing patent challengers to assert the same prior arts in both IPRs as well as district court proceedings as long as they assert another legal basis for invalidity. Patent challengers, for example, can argue that an invention is in public use, available to the general public, or on sale in district court proceedings based on prior art asserted during an IPR. These “grounds” are not allowed in an IPR.
