Survey Shows Trends in PTAB’s Willingness to Institute Multiple Petitions

Key Points

• While the Consolidated Trial Practice Guide generally disfavors multiple inter partes review (IPR) petitions, the Patent Trial and Appeal Board (PTAB) institutes them in roughly half the cases in which they are filed.
• The most common reasons petitioners cite for filing multiple petitions are the number or complexity of the claims and priority date disputes.

The Consolidated Trial Practice Guide states that, “[t]o date, a substantial majority of patents have been challenged with a single petition.” Consolidated Trial Practice Guide (November 2019) at 59. However, “the Board recognizes that there may be circumstances in which more than one petition may be necessary.” Id. Such circumstances include “when the patent owner has asserted a large number of claims in litigation or when there is a dispute about priority date requiring arguments under multiple prior art references.” Id.

To assist the PTAB in “determining whether more than one petition is necessary,” a petitioner is required to file a five-page ranking paper separately from the petitions that identifies “(1) a ranking of the petitions in the order in which it wishes the Board to consider the merits, if the Board uses its discretion to institute any of the petitions, and (2) a succinct explanation of the differences between the petitions, why the issues addressed by the differences are material, and why the Board should exercise its discretion to institute additional petitions if it identifies one petition that satisfies petitioner’s burden under 35 U.S.C. § 314(a).” Id. at 59–60. The patent owner is permitted to address the ranking paper, explaining “whether the differences identified by the petitioner are directed to an issue that is not material or not in dispute,” and if not, that “the patent owner should clearly proffer any necessary stipulations.” Id. at 60–61.

Despite the Consolidated Trial Practice Guide’s assessment that “multiple petitions by a petitioner are not necessary in the vast majority of cases,” many petitioners nonetheless file parallel¹ petitions that challenge the same patent. We offer an analysis of filings from July 1, 2021, to July 11, 2024, that shows trends among the Board in instituting or denying review where a petitioner files parallel petitions.

PTAB Institutes Multiple Petitions Roughly Half the Time

Our analysis includes decisions from the past three years — 45 total instances where parallel petitions were filed, identified from ranking papers (92 inter partes reviews (IPR) total)². In many cases, the decision to file multiple petitions is based on many factors — not only on the intrinsic factors of the case, but also extrinsic factors, like client directives. It is impossible to aggregate such a large amount of data while preserving the intricacies of individual cases, and our analysis below may overlook the details of any given case. Additionally, the parties may come to an agreement via a stipulation that obviates one of the parallel petitions, leading to its denial. Further, just as there are many reasons for filing multiple petitions, there are often many reasons for denying or granting institution of multiple petitions. We do our best to highlight representative decisions, but the details of the Board’s reasoning in every case are impossible to present in such a brief format. Below, we present brief excerpts of individual cases that are representative examples, or cases that offered informative arguments or results.

In general, of the 45 instances where a petitioner filed parallel petitions, 22 of those cases saw both or all petitions instituted, as opposed to 23 cases where institution of at least one petition was denied (a 49% success rate). In four of these instances, both petitions were denied. It is worth noting that, in the instances where the Board denied both petitions, the merits often played a substantial role. For example, the Board may have felt that the prior art challenge itself was lacking, and that it therefore did not need to consider its discretion to deny an additional petition. Overall, despite the Consolidated Trial Practice Guide’s statement that multiple petitions are “not necessary in the vast majority of cases,” a 49% success rate illustrates that the Board is clearly willing to embrace multiple petitions with sufficient justification.

Most Common Reasons for Multiple Petitions

The most common reason petitioners cited for filing multiple petitions, at least in part, was the number or complexity of the claims, accounting for 21 total instances of parallel petitions (47% of the total). Of those 21 instances, both petitions were instituted in eight instances (a 38% success rate). In general, the Board seems to greet this rationale with a healthy dose of skepticism, especially when the number of challenged claims was fewer than the typical 20 claims. However, the Board was willing in certain instances to institute two petitions when fewer than 20 claims were challenged, particularly when the petitioner demonstrated how a second petition would give the Board flexibility in its final decision. For example, in IPR2021-01309/IPR2021-01310, where a total of 18 claims were challenged, the petitioner explained how its two petitions each challenged a “unique subset” of claims that each recited distinct subject matter, thus allowing the Board to address the intricacies of the subsets separately. The Board accepted this reasoning and granted institution of both petitions. See IPR2021-01309, Paper 11 at 12 (“Given the complexity and differences in subject matter recited in the claims, we agree that the use of a single petition was not practical.”) IPR2023-01089/IPR2023-01090 is another example, where both petitions were instituted with only 14 claims at issue. As a disclaimer, some panels have opined that simply using a second petition to challenge a different statutory class of claims is not a sufficient justification (e.g., a “method” petition and a “system” petition). Below, we show a breakdown of the outcomes of the proceedings where the petitioner justified filing multiple petitions due to the number or complexity of claims.

Next, priority date disputes accounted for another major area where petitioners filed multiple petitions, accounting for nine instances (20% of the total). It is challenging to accurately assess the likelihood of success of this rationale in the aggregate, not only because it is heavily fact-dependent, but also because of the larger strategic developments in the case. For example, a patent owner may decide to stipulate that it will not challenge the prior art status of a reference, thus obtaining a discretionary denial of the lower-ranked petition. However, even in instances where a second petition is denied, a petitioner may see this as an overall strategic victory because it can move forward knowing that its asserted art is safe from a priority challenge (which presumably is strong art that justified a priority date challenge to begin with). What was clear from the data is that the Board almost unanimously accepts a patent owner’s stipulation as justification to exercise its discretion to deny a second petition, even if the art in the second petition is very strong on the merits. For example, in IPR2023-00183/IPR2023-00184, the patent owner presented a stipulation that it would not challenge the prior art status of a reference, thus obtaining a denial of a second petition. See IPR2023-00184, Paper 16 at 7–15. Interestingly, the art in the second petition had been used to obtain a successful invalidity decision in a final written decision against a similar patent. Id. at 10. Even in the face of the other successful IPR, the Board declined to institute the second petition, also rejecting the petitioner’s request to change the order of its ranking to place the second petition first. Id. at 14–15.

Additionally, “means-plus-function” (MPF) claims appeared to be an area where the Board was willing to embrace second petitions. Although only two instances of parallel petitions we analyzed challenged MPF claims, the Board instituted both petitions in both instances (see IPR2021-01458/IPR2021-01459 and IPR2023-00669/IPR2023-00670). The petitioner’s justification in both instances was substantively similar — both argued that the MPF claims were potentially indefinite, and they wanted the Board to consider those claims separately. IPR2023-00670, Paper 10 at 21 (citing Notice 4) (“[i]t would be unfair and counterproductive for the Board to be prevented from evaluating the unpatentability of the non-means-plus-function claims over the prior art simply because of the means-plus-function claims’ potential invalidity under §112”). In both instances, the Board seemed to appreciate this flexibility, and in one instance also noted the substantial words the petitioner had devoted to its MPF analysis. See IPR2023-00670, Paper 10 at 21. From our analysis, it seems that the Board is willing to institute second petitions when they concern MPF claims, even if (much) fewer than the standard 20 claims are being challenged.

Trends of Note

Finally, a few general trends in the data stood out. In multiple instances, a patent owner either failed to respond to a petitioner’s ranking paper or did so only after prompting from the Board. See, e.g., IPR2022-00100/IPR2022-00101. In these instances, the Board almost always instituted both petitions due to the complete absence of arguments from the patent owner. Additionally, panels seem to be split on whether a second petition overburdens the patent owner, particularly when art is shared between the petitions. Although there was no consensus, it was interesting to see a significant number of panels find that a patent owner would not be overburdened by a second petition simply because the same arguments could likely be presented for both petitions. See, e.g., IPR2023-00670, Paper 10 at 21–22. Of course, with respect to the opposing opinion when not instituting a second petition with similar art, the Board usually cited its finite resources or the ability of the petitioner to include the analysis together in a single petition. See, e.g., IPR2021-01533, Paper 20 at 14.

In conclusion, while petitioners must consider a wide range of intrinsic and extrinsic factors when deciding whether to file multiple petitions, the Board is clearly willing to embrace second petitions in certain scenarios.