A judgment in an interference disposes of all issues that were, or by motion could have properly been, raised and decided. A losing party who could have properly moved for relief on an issue, but did not so move, may not take action in the Patent Office after the judgment that is inconsistent with that party’s failure to move. 37 C.F.R. § 41.127. This is known as “interference estoppel,” , and was recently applied by the PTAB in partially denying an IPR petition. See Adama Makhteshim Ltd. v. Finchimica S.p.A., IPR2016-00577 (PTAB May 24, 2016) (order partially instituting IPR). The decision is important because it is a rare example of the PTAB’s consideration and application of interference estoppel to other Patent Office proceedings, including AIA trials.

Before the IPR petition was filed, the parties were adversaries in Interference No. 105,995, involving the same patent that is the subject of the IPR. In the interference, the IPR petitioner was the junior party, and the patent owner was the senior party. During the priority motions phase of the interference, the PTAB considered petitioner’s (the interference junior party’s) proposed printed publication prior art attacks on the patent based on various combinations of publications A through D. The PTAB issued an order (in August 2015) authorizing the petitioner to file a single motion challenging the patent claims as being unpatentable over Publication C. In refusing to authorize additional motions, the PTAB noted that “other proceedings within the Office may provide opportunities” to petitioner to challenge the claims on the other prior art, Publications A, B, and D. Petitioner filed the authorized motion, which the PTAB denied on its merits in a March 2016 decision that also concluded that petitioner was not the first to invent the interfering subject matter. Ultimately, the PTAB entered judgment (on priority of invention) against the petitioner/junior party.

While the interference was pending, in February 2016, the IPR petition was filed, presenting multiple grounds of unpatentability based on various combinations of publications A through D, and new publication E. The same PTAB panel administering the interference issued the institution decision on May 24, 2016, and, by that time, had already decided and entered judgment concluding the interference. In discussing whether interference estoppel applies to the petitioned grounds, the PTAB explained:

If a losing party in an interference filed a motion that was denied during the interference, that party is estopped from seeking the relief it sought in the denied motion in another proceeding before the office. Furthermore, if a losing party failed to raise an issue that it properly could have raised during the interference, it may not later raise that issue in another proceeding before the Office. If a party timely raises an issue but that issue is not decided during the interference, then estoppel does not apply. For example, if a party proposes to file a motion for relief on an issue but it is not authorized to file the motion, then the party could not have moved properly and estoppel does not apply for this issue.

Institution Decision, at 8–9. Of the four grounds of unpatentability the IPR petition presented, as summarized below, the PTAB applied interference estoppel to deny only two grounds, Grounds 2 and 4:

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The PTAB applied interference estoppel to Ground 2 because the petitioner could have properly raised this during the interference and sought the PTAB’s authorization to file a motion, but failed to do so. The PTAB applied interference estoppel to deny Ground 4 because the petitioner lost on the same challenge during the interference. The PTAB explained that interference estoppel does not, however, apply to Grounds 1 and 3 because the petitioner could not have properly moved, during the interference, for relief as it was not authorized to file a motion challenging patentability on this combination of prior art. The PTAB rejected the patent owner’s contention that patentability is a single issue for purposes of estoppel and, that the petitioner should thus be estopped as to all grounds on the basis of issue preclusion. The PTAB noted that the petitioner ought not be estopped from challenging patentability on a basis the PTAB previously refused to consider.

The PTAB’s application of interference estoppel here is consistent with its application of the estoppel provision of the AIA (35 USC § 315(e)). For example, in Apotex Inc. v. Wyeth LLC, IPR2015-00873, Paper 8 (PTAB Sept. 16, 2015), discussed here, the PTAB explained that a ground previously denied as redundant may be the subject of a subsequent IPR petition and will not implicate the IPR-estoppel provision, whereas the petitioner, in a subsequent IPR, likely will be estopped from presenting a previously unasserted ground that relies on prior art publications discussed in the earlier IPR petition.

The decision is instructive insofar as it provides an example of how interference estoppel can apply to an IPR proceeding involving the same patent and parties. Further, the decision is an example of the Patent Office assigning the same panel to administer an AIA trial that earlier administered a related inter partes proceeding. Lastly, perhaps, the decision offers an example of how the mere identification of a prior art challenge, if denied, may prevent application of estoppel to the same challenge later presented in a different proceeding within the Patent Office.