The US Court of Appeals for the Federal Circuit addressed, for the first time, the issue of when the Patent Trial & Appeal Board (Board) may raise a ground of unpatentability that was not advanced by a petitioner in relation to proposed substitute claims. The Court upheld the standard defining the “rare circumstances” in which such a ruling is proper while questioning the Board’s reasoning and application of the standard. Hunting Titan, Inc. v. DynaEnergetics Europe GMBH, Case Nos. 20-2163; -2191 (Fed. Cir. Mar. 24, 2022) (Prost, C.J., Reyna, Hughes, JJ.) (Prost, C.J., concurring).

Hunting Titan challenged DynaEnergetics’ patent in an inter partes review (IPR) based on anticipation and obviousness grounds. The Board found all the original claims of the patent unpatentable as anticipated. DynaEnergetics moved to amend to add proposed substitute claims. Hunting Titan opposed the motion to amend but advanced only obviousness grounds against the proposed substitute claims. The Board determined sua sponte that the proposed substitute claims were unpatentable as anticipated and, therefore, denied the motion to amend. DynaEnergetics requested rehearing, and the Precedential Opinion Panel (POP) reversed the Board’s denial of the motion to amend and determined that Hunting Titan did not prove that the proposed substitute claims were unpatentable.

The POP decided that “only under rare circumstances” should the Board sua sponte raise a ground for unpatentability not advanced by the petitioner in relation to proposed substitute claims. The rare circumstances include only two situations:

1. When the petitioner is not involved in the motion to amend, such as when a petitioner chooses not to oppose the motion or ceases to participate in the proceeding altogether

2. When evidence of unpatentability is readily identifiable and persuasive, such as if the substitute claims are unpatentable for the same reasons as the original claims.

The POP stated that in most circumstances, it is best to rely on the adversarial system and expect the petitioner to raise the unpatentability grounds for consideration.

The Federal Circuit upheld the POP’s standard for when the Board may sua sponte find proposed substitute claims unpatentable but also found the POP’s reasoning “problematic” because it placed too much emphasis on the adversarial system. The Court noted that Board proceedings, such as IPRs, are fundamentally a review of an earlier administrative proceeding, as opposed to civil litigation, The POP’s rationale was based on the public interest being served by an adversarial system rather than on the public interest being served by maintaining integrity of the patent system.

The Federal Circuit also questioned the POP’s application of its new standard to the case at hand, noting that the readily identifiable evidence exception should have been applied when the Board found the proposed substitute claims unpatentable for the same reasons it found the original claims to be unpatentable.

In her concurring opinion, Chief Judge Prost noted that “[i]t makes little sense to limit the [Board], in its role within the agency responsible for issuing patents, to the petitioner’s arguments.” Instead, “the Board must determine whether the patent owner’s newly-presented, narrower claims are . . . unpatentable in the face of the prior art cited in the IPR” (emphasis in original) (quoting Nike). The Court could not reverse the POP on application of its standard, however, because Hunting Titan failed to make that argument on appeal.

Practice Note: Subject to page limits and reasonableness, practitioners should raise all grounds for unpatentability against proposed substitute claims before the Board because the circumstances where the Board may sua sponte raise unpatentability grounds are rare and should not be relied upon.