37 CFR §42.23(b) limits the scope of a petitioner’s reply to evidence and arguments responsive to issues raised by a patent owner in its response to a petition for inter partes review (“IPR”). Petitioner replies exceeding this scope run the risk of being dismissed in their entirety by the Patent Trial and Appeal Board (“Board”) as “[t]he Board will not attempt to sort proper from improper portions of the reply.”1 Thus, while it may be tempting for a petitioner to include new evidence and arguments in a reply, petitioners must weigh the potential consequences of such additions and tie any new evidence and arguments to issues raised by the patent owner.

In the Board’s Trial Practice Guide, two “examples” are provided as red flags that evidence included in a reply may exceed the proper scope of the reply: (1) if the new evidence is necessary to make out a prima facie case for an original contention of anticipation or obviousness; and (2) if the new evidence could have been presented in a prior filing.2

The first red flag, whether the information is necessary to make out a prima facie case of unpatentability, was recently addressed by the Board in a final written decision considering whether it was proper for a petitioner to use evidence provided in a reply to supplement its original contention that a thesis located in a university library qualified as publicly accessible prior art. In this instance, the original petition included a stipulation from another district court proceeding where the patent owner and other parties agreed that the thesis qualified as prior art.3 The Board denied institution of the IPR on the grounds relating to the thesis, finding that the petitioner did not submit sufficient evidence to establish the thesis qualified as publicly accessible prior art. Regarding the stipulation submitted by the petitioner, the Board noted that that patent owner “may have agreed to stipulate to certain facts to streamline matters at trial . . . or had other reasons to stipulate on the issue . . . , regardless of whether the thesis was, in fact, publicly accessible or not.”4 In its reply, the petitioner attempted to supplement its showing of the public accessibility of the thesis with additional testimonial evidence from a university representative that a visitor could reasonably search for the thesis as of the priority date.5 The Board found, in its final written decision, that the petitioner had improperly supplemented its original contention and concluded that this additional evidence was indeed beyond the scope of a proper reply.6 In addition, the Board implied that one of the petitioner’s shortcomings was failing to show why this information was not provided in the petition.7

Despite the petitioner’s unsuccessful attempt to add evidence relating to the thesis in Argentum Pharm. LLC, the petitioner was successful in including new evidence and arguments in its reply that rebutted issues raised in the patent owner’s response. Specifically, the Board found that the petitioner’s additional clarifications and citations to a prior art reference were permissibly within the scope of petitioner’s reply since the prior art reference was being relied on in the same manner as in the petition and the evidence was provided in response to patent owner’s arguments.8 Similarly, the Board concluded that petitioner’s new evidence and arguments in response to the patent owner’s secondary considerations arguments were indeed properly included in the petitioner’s reply.9

The second red flag, where the evidence to be included in the reply could have been raised in a prior filing, was also recently addressed by the Board.10 In Activision Blizzard, the patent owner identified several portions of the petitioner’s reply that it believed to run afoul of 37 CFR §42.23(b) as including evidence that were “belated submissions,” which “contain information that was available at the time Petitioner filed its Petition.”11 The patent owner went so far as to file a motion to exclude these portions from the petitioner’s reply.12 In its final written decision, the Board permitted the allegedly belatedly presented evidence, finding, in part, that the arguments were responsive to patent owner’s allegations that during the deposition testimony of an author, the author could not identify his reference as one that was published and presented at a conference.13 In light of this finding, the Board also denied in part and dismissed in part patent owner’s motion to exclude.14

While the Board’s decision in Activision Blizzard implies that violation of the second red flag is not necessarily dispositive as to compliance with 37 CFR §42.23(b), the Board recently went even further to point out that simply because evidence could have been provided earlier does not render inclusion of that evidence in a petitioner’s reply improper.15 In Toro, a patent owner argued that the petitioner had not complied with 37 CFR §42.23(b) by merely alleging that a “[p]etitioner cannot submit additional, belated evidence in its Reply that supports its Petition if it could have been presented in a prior filing.”16 The Board disagreed, pointing out that “[t]his statement of the law is wrong.”17

In Toro, patent owner argued that petitioner improperly waited until its reply to present supplemental claim construction arguments, and instead, should have pursued supplemental briefing in view of the claim construction arguments presented in the patent owner’s preliminary response. The Board disagreed, finding it reasonable for petitioner to wait until the patent owner filed its post-institution response to see if patent owner would maintain its preliminary claim construction position.18 Thus, while the petitioner’s evidence to support its supplemental claim construction arguments could have been raised in supplemental briefing after the patent owner’s preliminary response, the Board determined that it was permissibly included in the petitioner’s reply. The Board further clarified that “[t]he mere fact that a Reply presents evidence that was not in the record previously does not make that evidence improper.”19 Thus, evidence that is submitted for the first time in a reply is not prima facie improper, even if it could have been presented earlier.

Given the possibility that a petitioner’s reply may be excluded in its entirety, petitioners should keep these two red flags in mind when drafting a reply. Specifically, petitioner’s should be mindful of the possible implications of including new evidence to establish a prima facie case for the anticipation or obviousness of a claim as well as when including new evidence that arguably could have been presented in an earlier filing. If new evidence is to be introduced in petitioner’s reply, the petitioner should take care to tie that new evidence directly to an argument raised by patent owner. To be sure, compliance with 37 CFR §42.23(b) is analyzed on case-by-case basis, but these two red flags are useful guide posts for petitioners drafting effective replies.