Accused Infringer Estopped from Asserting Prior Art Disclosed in Invalidity Contentions

Apr 10, 2018

Reading Time : 2 min

ZitoVault sued IBM and Softlayer Technologies, Inc. (“Softlayer”) (collectively, “Defendants”) for alleged infringement of U.S. Patent No. 6,484,257 (the “’257 Patent”). Soon after, the Defendants petitioned the Patent Trial and Appeal Board (PTAB) for inter partes review (IPR) of the ’257 Patent (“First Petition”) and requested to join a pending IPR on the same patent, filed earlier by Amazon.com, Inc. The Defendants submitted a nearly identical IPR petition as the one filed by Amazon. The PTAB granted joinder and issued a final written decision on April 11, 2017, holding that the challenged claims were patentable.

During the pendency of the First Petition, the Defendants filed a separate IPR petition (“Second Petition”) based on different prior art references. The PTAB denied institution of the Second Petition. Afterwards, plaintiff moved for summary judgment under 35 U.S.C. § 315(e)(2) asserting that statutory estoppel precluded IBM from arguing that the ’257 Patent is invalid as anticipated or obvious.

35 U.S.C. 315(e)(2) states that “[t]he petitioner in an inter partes review of a claim in a patent . . . that results in a final written decision . . . may not assert . . . in a civil action that the claim is invalid on any ground that the petitioner raised or reasonably could have raised during that inter partes review.” 35 U.S.C. 315(e)(2) (emphasis added). The First Petition did not raise any prior art references that were already identified in their invalidity contentions in district court. The Defendants essentially argued that estoppel does not apply based on the First Petition because they could not have raised additional prior art when seeking joinder because “[the] PTAB routinely denies joinder if a second-filed petition might introduce new arguments or grounds into a pending IPR.” Judge Lynn disagreed, however, stating that the PTAB does not require a “mirror image” rule to allow joinder and that joinder is discretionary, and whether the petition asserts new grounds is just one of the factors considered. Because the Defendants could have sought, but did not seek, to raise the prior art patents and publications discussed in their invalidity contentions, allowing the Defendants to raise arguments that they elected not to raise during the First IPR would provide them with “a second bite at the apple.” Therefore, Judge Lynn held that the Defendants IBM and Softlayer are estopped from arguing anticipation or obviousness in light of prior art references discussed in their invalidity contentions, but they can rely on prior art systems from their invalidity contentions.

ZitoVault LLC v. International Business Machines Corporation et al, 3-16-cv-00962 (TXND April 4, 2018, Order) (Lynn, USDJ)

Share This Insight

Previous Entries

IP Newsflash

December 9, 2025

The Federal Circuit recently denied a petition for a writ of mandamus that challenged the PTO Director’s reliance on “settled expectations” to discretionarily deny two inter partes review (IPR) petitions. In so doing, the court explained that, while it was not deciding whether the Director’s use of “settled expectations” was correct, the petitioner’s arguments about what factors the Director may consider when deciding whether to institute an IPR or post-grant review (PGR) are not generally reviewable and did not provide sufficient basis for mandamus review here.

...

Read More

IP Newsflash

December 5, 2025

District courts are split on whether a complaint can provide the required knowledge for post-suit indirect and willful infringement in that same lawsuit. Chief Judge Connolly in the District of Delaware recently confirmed that, consistent with his prior opinions, the complaint cannot serve as the basis for knowledge for either a claim of post-suit indirect infringement or a demand for willfulness-based enhanced damages in that lawsuit.

...

Read More

IP Newsflash

December 3, 2025

The Federal Circuit recently held that a patentee acted as its own lexicographer to define a claim term even though it did not explicitly define the term. Rather, because the patentee consistently and clearly used two terms interchangeably to describe the same structural feature and did so in all of the embodiments in which the feature appeared, the patentee impliedly gave the term its own, unique definition.

...

Read More

IP Newsflash

December 2, 2025

The Federal Circuit recently held an asserted patent was not entitled to its priority date because the priority application lacked written description support for the asserted claims. In so doing, the court explained that broad disclosures that do not provide reasonably specific support for narrower claims do not meet the written description requirement. The court also considered whether the inventor’s testimony showed they possessed the full scope of the claimed genus at the priority date or whether it was more likely the inventors first became aware of the claimed embodiments from public disclosures of the accused product.

...

Read More

© 2025 Akin Gump Strauss Hauer & Feld LLP. All rights reserved. Attorney advertising. This document is distributed for informational use only; it does not constitute legal advice and should not be used as such. Prior results do not guarantee a similar outcome. Akin is the practicing name of Akin Gump LLP, a New York limited liability partnership authorized and regulated by the Solicitors Regulation Authority under number 267321. A list of the partners is available for inspection at Eighth Floor, Ten Bishops Square, London E1 6EG. For more information about Akin Gump LLP, Akin Gump Strauss Hauer & Feld LLP and other associated entities under which the Akin Gump network operates worldwide, please see our Legal Notices page.