In a case of first impression, the Federal Circuit in Ingenico Inc. v. IOENGINE, LLC, 2023 1367 (Fed. Cir. May 7, 2025) clarified the scope of the inter-partes review (IPR) estoppel provisions set forth in 35 U.S.C. § 315(e)(2). At trial in the underlying declaratory judgment action, the district court allowed Ingenico to introduce evidence of sale/use of a prior art product (DiskOnKey Device) that the jury relied on in invalidating several claims of the patents-in-suit. Prior to trial, Ingenico had also filed IPR petitions that relied on documentation about the DiskOnKey Device – resulting in findings at the PTAB that other claims of the patents-in-suit were also invalid. On appeal, the patentee, IOENGINE, sought reversal of the district's court decision to allow in evidence of the sale or use of the DiskOnKey device because such evidence "are printed publications that reasonably could have been raised during the IPR."
In rejecting IOENGINE's position, the Federal Circuit focused on the meaning of the term "ground" as used in § 315(e)(2). The Court held that "a ground is not the prior art asserted during an IPR" further noting that "Congress precluded [IPR] petitioners from asserting grounds in district court." Thus, "IPR estoppel does not preclude a petitioner from relying on the same patents and printed publications [used in an IPR] as evidence in asserting a ground that could not be raised during the IPR, such as that the claimed invention was known or used by others, on sale, or in public use." As such, the Court made clear that "IPR estoppel applies only to a petitioner's assertions in district court that the claimed invention is invalid under 35 U.S.C. §§ 102 or 103 because it was patented or described in a printed publication (or would have been obvious only on the basis of prior art patents or printed publications) . . . [but] 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."
The decision resolves a split among district courts about the scope of IPR estoppel as to product art. It also reinforces the importance of performing a diligent search for product prior art – even products associated with patents or printed publications used in IPRs.
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