We have previously written about how the Federal Circuit and the PTAB are applying the AIA estoppel provisions.[1] Since the Federal Circuit’s Shaw ruling, several recent opinions have construed the scope of estoppel. Two of these cases, from district courts, cases have applied estoppel narrowly. But a recent PTAB decision, issued in the wake of these decisions, shows that the Board is not following the lead of the district courts, but instead is continuing to apply its broad approach to estoppel. It will likely be left to the Federal Circuit to resolve the difference, although the Court of Appeals recently declined an invitation to take on the issue.

Key Takeaway: There is a split of authority between the district courts and the PTAB regarding how narrowly or broadly to apply estoppel after a final PTAB decision. Based on the narrow scope of estoppel applied by the courts to date, parties should be prepared to litigate in court any invalidity grounds not actually included in a PTAB final written decision. Conversely, parties in PTAB proceedings should expect the Board to continue applying its broader view of estoppel, such that petitioners would likely be barred from maintaining grounds that “could have been raised” in a prior IPR. It will likely take a Federal Circuit appeal to review this issue and resolve this split in authority.

Background: Last year, the Federal Circuit considered the effect of the AIA estoppel provisions in connection with a PTAB final written decision under 35 U.S.C. §315(e). In a pair of cases (including Shaw), the court decided that IPR estoppel provisions in §315(e) will not apply to any invalidity ground that the petitioner raised in the petition but the PTAB chose to not institute for redundancy.[2]

These Federal Circuit cases left undecided the effect of the statutory estoppel provisions on grounds that a petitioner could have raised but did not include in the petition. Prior to those decisions, the Board had considered the effect of estoppel on grounds not included in the petition. In several rulings, the Board had applied a broad scope of estoppel not limited to those grounds on which trial was instituted.[3]

But district courts, now considering the scope of estoppel after Shaw, are ruling that Shaw limits estoppel to grounds actually instituted (or a subset thereof).

District Courts: Narrow Scope of Estoppel. Two recent district court opinions have considered the effect of Shaw on the scope of estoppel under 35 U.S.C. §315(e)(2) after a final written IPR decision. Both cases reached the same conclusion: under Shaw, estoppel only applies to those grounds that were actually raised (or could have been raised) during the IPR – that is, after institution. Under these rulings, grounds not included in the petition as filed are not subject to estoppel. The courts have reasoned that, in effect, only instituted grounds “could have been raised” during the review.

Intellectual Ventures v. Toshiba.[4] IV moved to preclude Toshiba from asserting invalidity challenges against one of the patents-in-suit, the ’819 patent, because Toshiba had filed an IPR petition as to that patent which resulted in a final written decision. In the IPR final decision, the PTAB concluded that the relevant claims of the ’819 patent were unpatentable as obvious over three references, two of which were named “Ogawa.” In the district court case, Toshiba asserted that the relevant claims were invalid based on the same “Ogawa” combination, along with another obviousness grounds based on a different combination including a reference named “Fuse.” IV asserted that Toshiba should be estopped from asserting invalidity not only as to the “Ogawa” combination but also as to the “Fuse” combination, arguing that the “Fuse” combination was based on publicly available patents or printed publications which could have been raised in the IPR.

Although the court agreed that Toshiba could have raised the “Fuse” obviousness grounds in the IPR petition, the court disagreed with IV that estoppel would bar Toshiba from asserting those grounds in district court. Instead, based on its reading of Shaw, the court held that estoppel was limited to those grounds actually raised “during” the IPR (namely, the “Ogawa” combination) – leaving Toshiba free to assert at trial those grounds not included in the IPR petition. In particular, the court pointed to the holding in Shaw that grounds rejected by the PTAB as redundant at the institution stage could not have been raised “during” the subsequent IPR trial. Although the district court recognized that extending the logic of Shaw to those prior art grounds never presented in the petition would “confound[] the very purpose of” parallel IPR proceedings, the court believed this result was required under the Federal Circuit’s interpretation of the estoppel provisions.

On reconsideration, the district court declined to change the prior ruling.[5] Recognizing that the Federal Circuit did not address the specific circumstances here (i.e., grounds not included in the petition), the court was “left with two options” centered on “different policy considerations” having “very different consequences.” On the one hand, applying estoppel broadly would force a challenger to include all relevant grounds in a petition, an approach inconsistent with the limitations imposed on IPRs (such as page limits). On the other hand, a narrowly-applied estoppel would permit a challenger to “play games” by asserting some references in an IPR and reserving others for litigation, an approach inconsistent with the availability of the administrative track to provide a faster and cheaper alternative for resolving disputes over patent validity. Ultimately, the court declined to make a policy choice between the two extremes, and left its initial ruling of a narrow estoppel in place.

Verinata v. Ariosa.[6] Plaintiffs moved to strike those portions of defendants’ invalidity contentions relying on grounds that were raised or could have been raised in prior IPR proceedings involving the asserted patents. Ariosa had filed an IPR directed to the ’430 patent, raising three obviousness grounds, one grounds including the combination of Dhallan and Binladen and another including the combination of Shoemaker, Dhallan and Binladen. The Board instituted trial only as to the latter of those grounds (i.e., the “Shoemaker” combination). After remand from the Federal Circuit, the Board issued a final decision rejecting the obviousness ground.

Ariosa also had filed an IPR on the ’794 patent, raising three prior art grounds, including anticipation by a reference named Fan. The PTAB instituted trial only as to the “Fan” anticipation grounds. After trial, the PTAB issued a final decision rejecting the anticipation ground. An appeal of that decision was pending before the Federal Circuit at the time of the district court’s ruling.

As in the IV v. Toshiba case, the parties here disagreed on the scope of statutory estoppel after Shaw. Plaintiffs argued that Shaw only applies in the specific circumstances in that case, which involved grounds not instituted because of redundancy. But as in IV v. Toshiba, the district court disagreed and held that Shaw has a broader reach due to its interpretation of the estoppel provisions, and was not limited to the redundancy circumstances present in that case. And similar to the ruling in IV v Toshiba, the court here concluded that, under Shaw, statutory estoppel only bars the petitioner from asserting invalidity grounds raised, or grounds that reasonably could have been raised, during the IPR.

With respect to the ’430 patent, the court held that defendants were estopped from asserting invalidity based on the combination of Shoemaker, Dhallan and Binladen, since that combination was the subject of the IPR trial. But, in addition, the court ruled that defendants could not assert the combination of Dhallan and Binladen, since it was a “subset” of the combination tried in the IPR. According to the court, the “subset” combination was or could have been raised during the IPR – even though the PTAB declined to institute on this specific ground as redundant. Finally, the court ruled that defendants were not estopped from raising a third prior art combination (“Quake”), since the PTAB declined to institute trial on that ground (on the merits).

PTAB: Broad Scope of Estoppel. After the Federal Circuit’s Shaw decision (and before the district court cases discussed above), the PTAB continued to apply estoppel broadly to prevent a petitioner from proceeding on grounds that “could have been raised” in a prior IPR. These cases did not, however, involve the specific circumstances in Shaw – grounds not instituted due to redundancy. In Kofax v. Uniloc,[7] the Board applied estoppel to bar a petitioner from proceeding with grounds that it “could have raised” in a prior IPR that resulted in a final decision, even though it actually did raise those grounds in a prior CBM where institution was denied; the Board reasoned that the petitioner could have added those grounds from the denied CBM into the IPR through joinder. Similarly, in Praxair v. INO Therapeutics,[8] the Board ruled that petitioner was estopped from raising grounds that it “could have raised” in a prior IPR, reasoning that petitioner had failed to prove it had conducted a “diligent” prior art search before filing the first IPR.

Great West v. Intellectual Ventures.[9] More recently, and after the two district court cases applying a narrow estoppel, the PTAB had occasion to reconsider the scope of statutory estoppel. In this case, petitioner sought review of claims 11-20 of the ’177 patent. Petitioner had filed three prior IPRs and a CBM on the ’177 patent. Two of those IPRs resulted in final written decisions covering claims 11-13 and 15-20 (but not claim 14); institution was denied in the third IPR as well as in the CBM. The present case presented grounds based on a reference (Robinson) not included in the previous cases.

Here, petitioner argued that statutory estoppel did not bar review of claims 11-13 and 15-20 because Shaw purportedly limited the scope of estoppel to only those grounds actually instituted for trial in the prior cases. Petitioner relied on the IV v.Toshiba decision in support of this position. However, the Board declined to follow the lead of the district courts, expressly rejecting the court’s decision in IV v. Toshiba.[10] Specifically, the Board rejected petitioner’s argument that Shaw limits estoppel only to instituted grounds, reasoning that Congress would not have included the phrase “or reasonably could have raised” in the statute if it intended to limit estoppel only to grounds “actually raised” at trial. Instead, the Board determined that Shaw merely held that estoppel does not apply to any unpatentability ground presented in a petition but denied institution.

Because petitioner “could have raised” grounds based on Robinson in the prior IPRs (but did not), the PTAB ruled that petitioner was estopped from pursuing those grounds in the instant case, and denied institution of claims 11-13 and 15-20. (Though estoppel did not apply to claim 14, the Board denied institution of that claim for other reasons.)

Federal Circuit: Estoppel Issue Does Not Warrant Mandamus. In connection with the Verinata case discussed above, Verinata (along with a co-plaintiff) recently sought a writ of mandamus from the Federal Circuit to overturn the district court’s ruling on statutory estoppel.[11] However, the Federal Circuit declined to issue the writ, finding that the right to relief sought by the plaintiffs was not clear and indisputable. The court noted that the “current state” of binding precedent does not compel finding that the district court “clearly abused its discretion.” Furthermore, the plaintiffs failed to establish that they had no other adequate remedy, such as raising the estoppel issue in an appeal on the merits after final judgment in the district court case.

In light of the Federal Circuit’s reluctance to weigh in on the estoppel issue in Verinata, it remains to be seen how the split of authority between the district courts and the PTAB will be resolved. While we do not know how the Federal Circuit may ultimately rule on the question, it is likely that the issue will eventually be presented on appeal from a district court ruling. Nevertheless, based on the narrow scope of estoppel applied by the courts to date, parties should be prepared to litigate in court any invalidity grounds not actually included in a PTAB final written decision. Conversely, parties in PTAB proceedings should expect the Board to continue applying its broader view of estoppel.