Court Clarifies Meaning of “Ground for Invalidity” for Purposes of Post-IPR Estoppel

May 18, 2017

Reading Time : 2 min

Under 35 U.S.C. § 315(e), a petitioner in an IPR is estopped from later asserting invalidity “on any ground that the petitioner raised or reasonably could have raised” during the proceeding. In Shaw Indus. Group, Inc. v. Automated Creel Sys., Inc., the Federal Circuit limited the reach of 315(e) by holding that its estoppel effect does not apply to any petitioned but non-instituted ground. 817 F.3d 1293 (Fed. Cir. 2016).  Here, the court was faced with interpreting the meaning of a petitioned “ground for invalidity,” which, under Shaw, would avoid 315(e)’s estoppel effect.

Plaintiff argued that Defendant’s current theory of how a prior art reference anticipates a claim is completely different from the theory that was previously presented to, and rejected by, the Patent Trial and Appeal Board (PTAB).  According to the Plaintiff, Defendant’s new theory is a different invalidity “ground,” which Defendant only set forth after the PTAB was not persuaded by its original theory.  Plaintiff contended that a denied “ground” should not be broadly interpreted to include the claim, the prior art references, and the general theory of invalidity. Rather, for purposes of the estoppel effect, a “ground” should be narrowly limited to the petitioner’s element-by-element invalidity analysis with specific citations to evidence that was presented in the IPR petition. Plaintiff further argued that, if a “ground” is not limited in this way, “a defendant could assert numerous bare-bones grounds in an IPR petition, knowing that those grounds would be rejected by the PTAB, but thus preserved [under Shaw] for later use in the district court.”

In clarifying the meaning of a “ground for invalidity,” the court first recognized that a defendant could construct a “brand-new invalidity theory” using the same prior art that it presented in its petition for IPR. Because of this possibility, the court explained that if the “thrust” of a defendant’s invalidity theory is different from that presented to the Patent Trial and Appeal Board (PTAB), it is probably subject to the estoppel effect of 315(e). The court further explained that a defendant is not locked into the precise arguments that it made to the PTAB. However, “if the new theory relies on different, uncited portions of the prior art, attacks different claim constructions, or relies on substantially different claim constructions, then the new theory is tantamount to a new invalidity ground, and the court will treat it like a non-petitioned ground subject to estoppel.”

Douglas Dynamics, LLC v. Meyer Prods. LLC, 14-cv-886 (W.D. Wis. May 15, 2017) (J. Peterson)

Share This Insight

Previous Entries

IP Newsflash

July 11, 2025

The Federal Circuit recently reversed a PTAB determination on remand that a patent was obvious over applicant admitted prior art (“AAPA”) in combination with prior art patents, holding that expressly designating AAPA as a “basis” for a ground is improper under 35 U.S.C. § 311(b). In doing so, the Court rejected the PTAB’s “blanket rule” that “AAPA used in combination with prior art patents or printed publications under § 311(b) is ipso facto not the basis or part of the basis of a ground.” Ultimately, while the case clarifies that expressly listing AAPA in an IPR ground is improper, the precise line between proper and improper uses of AAPA in other instances remains unclear.

...

Read More

IP Newsflash

July 1, 2025

In an appeal from an inter partes review, the Federal Circuit recently clarified that the enablement inquiry applied to prior art references in the context of an anticipation defense differs from the enablement inquiry applied when evaluating the claims of a patent.

...

Read More

IP Newsflash

June 26, 2025

The Northern District of Ohio denied a motion to compel the plaintiff to produce test results referenced in its initial disclosures and complaint. The court found that because the “test results are not facts but rather are opinions,” the information was protected as work product. Furthermore, because that testing would not be used as evidence in the litigation, the defendant was not prejudiced.

...

Read More

IP Newsflash

June 6, 2025

In a precedential opinion, the Federal Circuit definitively held that the Patent Trial and Appeal Board has jurisdiction over IPRs that concern expired patents.

...

Read More

IP Newsflash

June 6, 2025

In a patent infringement litigation in the U.S. District Court for the Eastern District of Texas, Judge Rodney Gilstrap denied a joint motion to stay the litigation pending resolution of inter partes review when it was uncertain that all defendants would be bound by the statutory estoppel provision of 35 U.S.C. § 315(e).

...

Read More

IP Newsflash

May 30, 2025

A district court recently dismissed a patent infringement complaint for improper venue under 28 U.S.C. § 1400(b), finding that the storage and distribution of products from an Amazon warehouse was not sufficient to establish that warehouse as a regular and established place of business in the district.

...

Read More

IP Newsflash

May 27, 2025

The Federal Circuit affirmed a District of Delaware finding of non-infringement in an ANDA litigation due to the patentee’s clear and unmistakable disavowal of claim scope during prosecution. Specifically, the court held that statements made during prosecution of a parent application before the asserted claims were allowed amounted to a prosecution disclaimer that extended to subsequent patents in the family. In reaching this conclusion, the court rejected an attempt by the patentee to resurrect the claim scope through a unilateral, self-serving statement made in later applications in the family.

...

Read More

IP Newsflash

May 13, 2025

The Federal Circuit recently affirmed a district court’s holding that patent term extension (PTE) for a reissued patent was properly based on the issue date of the original patent and not that of the reissued patent. The Federal Circuit concluded that, where both the original and reissued patents claimed a drug product under regulatory review, using the issue date of the original patent to calculate PTE comports with both the purpose of the Hatch-Waxman Act and the related statutory context.

...

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.