As strategies for managing multiple inter partes reviews (IPRs) of the same or related patents evolve, so does the complexity of collateral estoppel. Collateral estoppel prevents a party from having to re-litigate issues that have been fully and fairly tried in a prior proceeding. It applies across both the administrative (issues decided in IPRs) and civil (issues decided in district court) contexts.

The Federal Circuit recently decided two cases resolving collateral estoppel issues arising from IPR decisions. The first, Nestle v. Steuben Foods, addressed the preclusive effect of claim construction across related patents. The second, MaxLinear v. CF Crespe, dealt with the preclusion implicated by the relationship between independent and dependent claims across multiple petitions challenging the same patent.

Nestle USA, Inc. v. Steuben Foods, Inc., 884 F.3d 1350 (Fed. Cir. 2018)

The petitioner in Nestle challenged two related patents in successive IPR petitions. In defending the first petition, the patent owner argued the meaning of the term “asceptic” as used in the challenged claims. The Board’s determination, including the proper claim construction, was then appealed to the Federal Circuit. The Court found that the term “asceptic,” was governed by the patentee’s lexicography and construed it accordingly. The Court then affirmed the Board’s ultimate determination in favor of the patent owner.

The second petition challenged similar claims reciting the term “asceptic” in a related patent that contained nearly identical lexicography. The Court explained that the proper construction of the term “asceptic” was already resolved in the previous IPR, which also involved the same parties. In this case, collateral estoppel protected the patent owner from having to revisit an issue already resolved against the patent challenger. Collateral estoppel thus applies to claim construction issues across subsequent IPR petitions.

Collateral estoppel applies to claim construction issues across subsequent IPR petitions, protecting the patent owner from having to revisit an issue already resolved against the challenger.

MaxLinear, Inc. v. CF Crespe LLC, 880 F.3d 1373 (Fed. Cir. 2018)

MaxLinear addressed similar collateral estoppel issues, this time in the context of independent and dependent claims. In this case, MaxLinear filed an IPR petition challenging the independent claims of Crespe’s patent. The Board ultimately found that the independent claims were unpatentable over the cited prior art. While that decision was pending appeal, MaxLinear filed a subsequent petition challenging all of the claims of the same patent over different prior art. The Board found on the merits that the challenged claims were not unpatentable over the prior art cited in the second petition. That decision was appealed as well.

During the pendency of the second petition, the Federal Circuit affirmed the unpatentability of the independent claims from the first petition. The Court found that its affirmance    of the decision in the first petition abrogated the Board’s findings on the independent claims in the second petition. The Court then vacated the Board’s determination related to the dependent claims in the second petition and remanded to the Board. On remand, the Board was instructed to determine whether there were any material differences between the dependent and independent claims such that the dependent claims could survive the unpatentability of the independent claims under the prior art cited in the first petition. If not, then the patent owner’s defense of the dependent claims in the second petition (over the prior art cited in the second petition) is collaterally estopped by the patentability determination in the first petition (over the prior art cited in the first petition).

MaxLinear thus presents the situation in which the Board is tasked with making a patentability evaluation of claims challenged in one petition based on different prior art cited against different claims in a different petition. Despite the complexity of that layering, collateral estoppel in this case protects the Board from wasting time adjudicating subject matter that has already been found unpatentable in prior IPRs.

Collateral estoppel protects the Board from wasting time adjudicating subject matter that has already been found unpatentable in prior IPRs, even if determining estoppel requires the Board to evaluate patentability of previously unchallenged claims based on prior art not raised in the instant petition.