Ingenico: Federal Circuit Narrows the Scope of IPR Estoppel Under § 315(e)(2)

On May 7, 2025, the Federal Circuit issued a precedential decision in Ingenico Inc. v. IOENGINE, LLC that narrows the scope of inter partes review (IPR) estoppel under 35 U.S.C. § 315(e)(2), resolving a longstanding district court split on the type of invalidity grounds and prior art that are precluded under the IPR estoppel provision. Case No. 2023-1367 (May 7, 2025). Specifically, the court held that defendant Ingenico, who had previously challenged the patents at issue in IPRs, was not estopped from relying on product prior art along “with related printed publications at trial to prove the claimed invention was known or used by others, on sale, or in public use.”

Under § 315(e)(2), an IPR petitioner who received a final written decision addressing the patentability of a claim is estopped in district court or at the International Trade Commission (ITC) from asserting that the claim is invalid “on any ground that the petition raised or reasonably could have raised during” the IPR. For years, district courts were split on the scope of this estoppel as applied to product art. Some courts held that defendants are estopped from bringing invalidity grounds based on product art that is “materially identical” to printed publications that could have been raised in an IPR, whereas others (taking a more literal reading of the statute) held that IPR estoppel does not apply to such art since products cannot be asserted in IPRs, which are limited to patents and printed publications.

In Ingenico, the Federal Circuit affirmed a decision by Judge Bryson (sitting by designation in the District of Delaware) that Ingenico’s invalidity grounds based on product and printed publication art were not estopped under § 315(e)(2). The court’s decision turned on its interpretation of “ground” in the statute. The court explained that “grounds are the theories of invalidity available to challenge a claim under §§ 102 and 103,” while “prior art is evidence of a ground” and is “not coextensive with a ground.” Section 315(e)(2), which addresses invalidity grounds, thus “does not preclude a petitioner from relying on the same patents and printed publications 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.” Accordingly, defendant Ingenico was not precluded from relying on product and printed publication art to advance invalidity grounds that could not have been advanced in the prior IPRs, including that the claimed invention was known or used by others under pre-AIA § 102(a) or that the claimed invention was on sale or in public use under pre-AIA § 102(b). This was true irrespective of whether Ingenico’s product art is cumulative of art that Ingenico could have reasonably raised in the IPRs.

Key Takeaway:

• Ingenico narrows the scope of estoppel under § 315(e)(2) so that theories of invalidity relying on product prior art may be advanced in district court to show that a claimed invention was known or used by others, on sale, or in public use, regardless of whether the evidence supporting those invalidity theories was raised or reasonably could have been raised in a prior, related IPR.