Post-Grant Review (PGR)

April 21, 2021

A PGR is a trial proceeding conducted by the Patent Trial and Appeal Board (PTAB) to determine the patentability of one or more claims of a patent that issued from an application filed after March 15, 2013. A PGR is only available in the nine months following issuance of a patent.

The scope of challenges is much broader for PGRs compared to inter partes reviews (IPRs). In a PGR proceeding, the PTAB can institute trial on the basis of ineligible subject matter, lack of utility, lack of novelty, obviousness, lack of written description or enablement, and/or double patenting (i.e., almost all invalidity challenges except those based in equity jurisprudence, including allegations of inequitable conduct).

Although PGR proceedings take place before the PTAB at the US Patent and Trademark Office (USPTO), they have some similarities to civil trials. In both IPRs and PGRs, the parties can submit testimony in depositions and collect evidence, but, as was noted above, discovery is much more limited in front of the PTAB as compared to during litigation.

To institute a PGR proceeding against a subject patent, a petitioner that has not previously filed a civil action challenging the validity of a claim of the subject patent must file a petition within nine months after patent issuance. Similar to an IPR, a PGR petitioner need not meet the standing requirements necessary for filing a declaratory judgment action in civil court, i.e., there is no requirement that there be an apprehension of suit (although this can create some risks in terms of having the requisite standing to appeal an adverse decision from the PTAB). Also, IPR and PGR petitioners may not file their petitions anonymously.

In order to secure institution of a PGR, a petitioner must either

  • show that it is more likely than not that at least one claim of the challenged patent is unpatentable, or
  • raise a novel or unsettled legal question that is important to other patents or applications.

If the petition is granted, the PGR petitioner need only demonstrate the unpatentability of a challenged claim by a “preponderance of the evidence” rather than the “clear and convincing” standard used in civil court. A final determination by the PTAB will generally issue within one year of institution of the PGR (or 18 months from filing).

Like IPRs, PGRs offer several benefits for a challenger compared to other proceedings used to invalidate a patent:

  • PGR proceedings take less time than litigation to reach a final disposition—typically 18 months or less.
  • PGR proceedings are a cost-effective alternative to litigation, including due to the much more limited discovery that is available during PGR proceedings.
  • The challenger’s standard of proof for invalidating a patent is preponderance of the evidence rather than clear and convincing evidence, giving the challenger a greater likelihood of success.
  • In addition to anticipation and obviousness based on a printed publication or product prior art, a challenger may assert unpatentability of a patent on the basis of lack of enablement, lack of written description, and lack of patent-eligible subject matter (IPR proceedings allow only anticipation and obviousness challenges based on printed publications).

Although PGR is used as an alternative to civil litigation, petitioners should be wary of the broad potential estoppel effects of a PGR proceeding on subsequent litigation or other administrative proceedings (e.g., US International Trade Commission or USPTO actions). Like IPRs, estoppel after a PGR likely applies to estop the petition from raising arguments in subsequent litigation or other administrative proceedings that were raised or reasonably could have been raised during the PGR. Because the available challenges in a PGR are broader than those available in an IPR, the potential estoppel after a PGR is therefore broader and should be carefully considered when weighing the decision to file a PGR petition.