On July 6, 2023, the United States Patent and Trademark Office (USPTO) published an updated study analyzing the filing of multiple petitions at the Patent Trial and Appeal Board (PTAB) under the America Invents Act. The study separately analyzed the practices of filing serial petitions and parallel petitions, as well as the frequency and effectiveness of the same post-grant petitioner filing multiple petitions from 2015-2022.

A "serial" petition refers to a follow-on petition filed more than 90 days after the petitioner files a first petition challenging the same patent. A "parallel" petition refers to a petition filed fewer than 90 days from the first petition by the same petitioner against the same patent.

Overall, the study noted a decline in the number of both serial and parallel petitions filed from 2015-2022. The study further found an increase in the number of single-petition challenges to patents, which increased (as a proportion of total petition filings) from 66% in 2015 to 72% in 2022.

Two noteworthy cases drove the trends in serial petitions. Following the PTAB's issuance of its decisions in NVIDIA Corp. v. Samsung Elecs. Co., Case IPR2016-00134, Paper 9 (PTAB May 4, 2016), and General Plastic Industrial Co., Ltd. v. Canon Kabushiki Kaisha, Case IPR2016-01357, Paper 19 (PTAB Sept. 6, 2017), the number of serial petitions filed decreased significantly. In NVIDIA, the Board listed several factors for evaluating how multiple challenges to the same patent will be adjudicated. Those factors are:

  • Whether the same petition previously filed a petition directed to the same claims of the same patent;
  • Whether at the time of filing the first petition the petitioner knew of the prior art asserted in the second petition or should have known of the prior art;
  • Whether at the time of filing the second petition, the petitioner had received the patent owner's preliminary response to the first petition or received a decision from the Board on whether to institute review of the first petition;
  • The length of time elapsed between the time the petitioner learned of the prior art asserted in the second petition and the filing of the second petition;
  • Whether the petition provides adequate explanation for the elapsed time;
  • The finite resources of the PTAB; and
  • The requirement to issue a final determination not later than one year after institution

In General Plastic, a precedential decision, the PTAB reiterated the NVIDIA factors and held that the PTAB may discretionarily deny a petition using the seven non-exclusive NVIDIA factors.

The PTAB followed a similar trend for parallel petitions after issuing its decision in Comcast Cable Commc'ns, LLC v. Rovi Guides, Inc., IPR2019- 00224, Paper 10 (PTAB Apr. 3, 2019). In that decision, the Board requested additional briefing from the parties regarding why two or more petitions challenging the same patent are (or are not) warranted. Following the Comcast decision, the USPTO in 2019 released its Trial Practice Guide Update, which provided additional guidance for petitioners filing parallel petitions. The TPG Update indicated that, among other things, two or more petitions filed by a petitioner "should be rare."

The methodology used to report the updated study's information has changed compared to previous versions of the study. The Appendix of the study states, "In the updated method, the number of challenges is the number of times one petitioner challenged one patent in a fiscal year, only looking at those challenges that received a decision to institute. The fiscal year is calculated from the decision to institute date unless there was a request for rehearing decision that granted a request for rehearing of a decision denying institution, in which case the date of the request for rehearing was used." In contrast, the USPTO's previous methodology calculated the total challenges to a patent by adding the number of serial petitions, parallel petitions, and single petitions for each fiscal year, which led to petitions being counted twice in some cases.

Overall, since the USPTO's 2019 guidance, petitioners have filed significantly fewer sets of multiple petitions (both in serial and parallel filings). The results of the study will be used to help inform future USPTO reforms, including balancing the need for petitioners to file multiple petitions to make their case against the need for patent owners to be protected from repetitive challenges. The USPTO is also assessing comments from its proposed rulemaking on PTAB practices.

An Executive Summary of the study is available here.

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