PTAB Warns Petitioners That Follow-On Petitions Will Face Additional Scrutiny

September 28, 2017

A recent expanded panel decision, which lists factors the PTAB will use in exercising its discretion to institute serial IPR petitions, is afforded an “informative” designation.

A party that seeks to challenge a patent by way of inter partes review (IPR)—especially a defendant in an ongoing infringement litigation—has always been motivated to file its IPR petition as soon as possible. This is especially the case where the petitioner seeks to stay corresponding litigation, as some courts have denied motions to stay where the defendant was perceived as waiting too long to file the IPR petition. Additionally, because a successful IPR may end the litigation, the earlier a petition is filed, the earlier the suit (and its associated costs) will end.

A recent decision from the Patent Trial and Appeal Board (PTAB or Board), General Plastic Indus. Co. v. Canon Kabushiki Kaisha,[1] counterbalances these concerns and counsels a more deliberate approach.

In General Plastic, an expanded panel of the PTAB maintained a denial of institution of a follow-on (or serially filed) IPR petition based not upon the merits of the petitioner’s unpatentability arguments but instead upon considerations of efficiency and fairness.

While a denial of a serially filed petition is not new, the expanded panel’s decision clearly enumerated the factors that the Board considers when deciding whether to deny such a petition. This decision recently gained an “informative” designation; accordingly, while not binding, the decision nevertheless provides norms and guidance on the issue of serial petitions. As such, any party contemplating filing a subsequent petition for a patent should consider reviewing this decision.

General Plastic

In General Plastic, the petitioner filed two IPR petitions in September 2015 challenging two patents. After considering the petitions on the merits, the PTAB denied institution in March 2016. The petitioner sought rehearing, but this was denied in May 2016. The petitioner then performed prior art searches, and these searches uncovered references that were not used in the first pair of petitions and not considered by the patent examiner. The petitioner filed further petitions in July 2016 challenging the same two patents based in part on these references.

Rather than addressing the merits of these follow-on petitions, the PTAB exercised its discretion to deny institution. In particular, the PTAB considered the following seven factors, which were first articulated by the PTAB in May 2016:

  1. The finite resources of the Board
  2. The requirement under 35 U.S.C. § 316(a)(11) to issue a final determination not later than one year after the date on which the Director notices institution of review
  3. Whether the same petitioner previously filed a petition directed to the same claims of the same patent
  4. Whether at the time of filing of the first petition the petitioner knew of the prior art asserted in the second petition or should have known of it
  5. Whether at the time of filing of the second petition the petitioner already received the patent owner’s preliminary response to the first petition or received the Board’s decision on whether to institute review in the first petition
  6. The length of time that elapsed between the time the petitioner learned of the prior art asserted in the second petition and the filing of the second petition
  7. Whether the petitioner provides adequate explanation for the time elapsed between the filings of multiple petitions directed to the same claims of the same patent

Applying these factors to the facts surrounding petitioner’s subsequent petitions, the PTAB found the prejudice to the patent owner to be greater than that to the petitioner and denied institution.

The petitioner requested rehearing on the denial of institution. Chief Judge David Ruschke expanded the panel to hear the patent owner’s request “due to the exceptional nature of the issues presented” and “to provide a discussion of factors that are considered in the exercise of the Board’s discretion” to deny follow-on petitions. The expanded panel recognized that although there is no per se bar precluding the filing of multiple petitions against the same patent, the PTAB possesses statutorily granted discretion to deny such petitions. Regarding the exercise of this discretion, the expanded panel sanctioned the seven factors employed by the original panel.

Petitioners Should Expect Greater Scrutiny of Follow-On Petitions

At a recent Intellectual Property Owners Association conference held in San Francisco, Chief Judge Ruschke made clear that petitioners should expect greater scrutiny from the PTAB on follow-on or serially filed petitions. The expanded panel stated as much when it held that the seven factors “at the very least, serve to act as a baseline of factors to be considered in our future evaluation of follow-on petitions.” Furthermore, Chief Judge David Ruschke recently designated this opinion as “informative.” While such a designation does not render the General Plastic decision binding, the PTAB is likely to apply the seven-factor test, or some variation of it, for any future follow-on petition.


In the wake of General Plastic, parties should proceed deliberately before filing their PTAB petition(s), as the first petition may be the only one that the PTAB considers on the merits. Further, parties that discover a basis to file a follow-on petition should do so without undue delay and address the General Plastic factors in the petition.


If you have any questions or would like more information on the issues discussed in this LawFlash, please contact the authors, Dion M. Bregman (Silicon Valley) or any of the following lawyers from Morgan Lewis’s post-grant proceedings team:

Joshua M. Dalton

Century City
Andrew V. Devkar

Jason C. White

C. Erik Hawes
Rick L. Rambo

Louis W. Beardell, Jr.

Silicon Valley
Andrew J. Gray IV
Michael J. Lyons

Washington, DC
Jeffrey G. Killian, Ph.D.
Robert Smyth, Ph.D.

[1] IPR2016-01357, -01358, -01359, -01360, -01361