Recently, the Patent Trial and Appeal Board (“the Board”), issued an informative decision in Apotex Inc., v. Wyeth, LLC, IPR2015-00873 (“the ‘873 IPR”), providing insight into how the Board will apply estoppel under 35 U.S.C. §315(e)(1) and exercise its discretion under 35 U.S.C. §325(d). Previously, Apotex filed an IPR petition, IPR2014-00115 (“the ‘115 IPR”), against the same patent at issue in the ‘873 IPR, which resulted in the issuance of a Final Written Decision. In view of the Final Written Decision in the ‘115 IPR, the patent owner asserted that Apotex was estopped from “requesting inter partes review because the asserted grounds are based on prior art that the petitioner ‘was aware of, cited and relied upon [in the previous] ‘115 IPR.’” Finding that the preconditions for §315(e)(1) estoppel applied, the Board found that the petitioner was estopped from raising one of the two asserted grounds. No estoppel applied to the other ground, however, because the ground was merely raised, but not instituted on, in the earlier proceeding.

The Board acknowledged that 35 U.S.C. §315(e)(1) precludes a petitioner from requesting or maintaining a ground that a “petitioner raised or could have reasonably raised during that [previous] inter partes review [which resulted in a final written decision].” Since the petitioner in this IPR and the ‘115 IPR is the same, and the ‘115 IPR resulted in a final written decision, the Board found that the “preconditions for applying §315(e)(1) [estoppel] are in place.”

Apotex asserted two grounds in its petition and the Board reviewed each ground separately. With respect to Ground 2, the Board found that the petitioner could have raised this ground in the ‘115 IPR because each of the references relied upon in the ‘873 IPR were cited in the prior IPR. While Apotex did not assert the particular combination against the patent, Apotex was aware of and cited to all the references asserted in Ground (2) in the ‘115 IPR. Apotex, however, argued that because several grounds in the ‘115 IPR were found to be redundant, they could not have reasonably raised this particular ground in the ‘115 IPR.  The Board here was not persuaded and stated that the “[p]etitioner did not know, at the time it filed the ‘115 Petition, that the Board would find the grounds proposed therein to be redundant.” In effect, the Board states that a petitioner cannot rely upon later-occurring events in the proceeding to explain why a petitioner could not have raised a ground in the prior IPR to avoid §315(e)(1) estoppel. The fact of the matter is that the petitioner was aware of each of the references it asserted in Ground 2 of the ‘873 IPR, but failed to assert that combination in the prior ‘115 IPR. Since the petitioner could have raised Ground 2 during the ‘115 IPR, but chose not to do so, the petitioner was estopped from raising Ground 2 in the ‘873 IPR.

In contrast, the Board found that the petitioner was not estopped under §315(e)(1) from raising Ground 1, which was previously asserted in the ‘115 IPR as Ground 6.  In the ‘115 IPR, the Board declined to institute trial on Ground 6, finding that it was redundant.  The Board concluded that because it “did not reach the merits of the challenge presented in Ground 1 when deciding whether to institute a trial in the ‘115 IPR, we determine that Petitioner is not stopped from asserting Ground 1 in this proceeding.” The Board explained that “grounds raised during the preliminary proceeding, but not made part of the instituted trial, are not raised “during” an inter partes review and cannot be the basis for estoppels under 35 U.S.C. §315(e)(1).” Thus, since Ground 6 could not have been raised during the inter partes review (which review occurs only after institution of trial), the Board found that Apotex was not estopped from asserting Ground (1)¹ in the ‘873 IPR.

The patent owner further argued that the Board should exercise its discretion under 35 U.S.C. §325(d) to decline to institute inter partes review as the grounds asserted in the ‘873 IPR were based on “the same or substantially the same prior art arguments previously [presented].” The Board, however, noted that the permissive language of §325(d) “does not prohibit instituting inter partes review based on arguments previously presented to the Office” and that it “did not reach the merits of Petitioner’s arguments with respect to Ground 1 when considering the ‘115 IPR.” Id. at 9. For these reasons, the Board chose to not exercise its discretion “to decline an inter partes review of the ‘828 patent under §325(d).”

This informative decision provides insights for both petitioners and patent owners. In view of the clarified framework for the §315(e)(1) estoppel, petitioners would be wise to take stock of the differences in the disclosures of the combination of prior art in order to include various combinations of that art. Notably, grounds that were raised but not instituted on in an earlier petition, according to this decision, could not have reasonably been raised during the inter partes review and will not bar petitioners from raising those grounds in a subsequent review.