The Federal Circuit’s decision in ironSource Ltd. v. Digital Turbine, Inc., Case No. 24-1460 (Fed Cir. Apr. 8, 2026), offers a pointed reminder that success at the Patent Trial and Appeal Board does not guarantee access to appellate review. For companies that regularly use post-grant proceedings as part of a broader patent strategy, the case highlights a structural tension: the ability of patent owners to amend claims can effectively eliminate a challenger’s standing to appeal, even after the challenger has invested heavily in the proceeding.
At a high level, the court dismissed the appeal for lack of Article III standing. But the reasoning goes further. The decision clarifies that standing must track the specific claims that exist at the time of appeal—not the claims that existed when the dispute began, and not the claims that motivated the original challenge. When those claims change, the challenger’s evidence of injury must change with them.
This creates a moving target that petitioners ignore at their peril.
Background and Procedural Posture
Digital Turbine owns U.S. Patent No. 11,157,256, which relates to installing mobile applications in the background without redirecting users to an app store. ironSource petitioned for post-grant review, challenging the original claims on multiple grounds, including Sections 101, 102, and 103.
After institution, Digital Turbine filed a motion to amend. Its initial attempt was unsuccessful, but it followed with a revised motion proposing substitute claims 23–37. These claims introduced additional limitations—specifically, features relating to eligibility tokens and querying an address repository—that narrowed the scope of the claims relative to the originals.
The Board ultimately found the original claims unpatentable but upheld the substitute claims. ironSource appealed.
That is where things unraveled.
The Standing Framework
The Federal Circuit began with familiar principles. Although Article III standing is not required to initiate a PGR proceeding, it is required to appeal an adverse decision. The appellant bears the burden of establishing standing at the time the appeal is filed.
The court relied on a standard three-part test drawn from Spokeo, Inc. v. Robins and Lujan v. Defenders of Wildlife: the appellant must show (1) an injury in fact, (2) traceable to the appellee’s conduct, and (3) redressable by a favorable decision.
In patent cases, the “injury in fact” prong often turns on whether the challenger faces a substantial risk of infringement liability. The Federal Circuit has developed a line of cases—including JTEKT Corp. v. GKN Automotive Ltd. and Phigenix, Inc. v. Immunogen, Inc.—requiring concrete plans for potentially infringing activity.
Generalized assertions or past conduct are not enough.
ironSource’s Theory of Injury
ironSource relied primarily on a declaration from its Senior Director describing Digital Turbine’s alleged “veiled threats” regarding infringement of certain “Click-to-Install” (C2I) features in ironSource’s Aura product.
According to the declaration:
- Digital Turbine communicated to customers that its patents covered these features
- ironSource modified its product and provided indemnities to mitigate risk
- ironSource ultimately suspended the product
- it intended to reintroduce similar functionality but was deterred by the Board’s decision
On its face, this looks like a standard standing narrative. The Federal Circuit has accepted similar evidence in prior cases where a party shows that its product development plans create a real risk of infringement.
But the court found a critical disconnect.
The Missing Link: Substitute Claims
The court emphasized that the relevant claims for standing purposes were not the original claims ironSource had challenged, but the substitute claims that survived the PGR.
Those substitute claims included two additional limitations that narrowed their scope. And ironSource’s evidence did not address those limitations at all.
The declaration tied Digital Turbine’s alleged threats and ironSource’s business decisions to earlier patents and broader claim sets. It did not explain how the modified C2I features would implicate the new limitations introduced in the substitute claims.
That gap proved fatal.
As the court explained, standing requires a concrete link between the appellant’s planned conduct and the specific claims at issue. Here, ironSource failed to show that its intended product would infringe—or even risk infringing—the narrower substitute claims.
Without that link, there was no injury in fact.
Attempted Reliance on General Electric
At oral argument, ironSource invoked General Electric Co. v. Raytheon Technologies Corp., where the Federal Circuit found standing based on declarations that only “obliquely” connected a product design to claim limitations.
The comparison did not hold.
In General Electric, the declarations still provided a plausible mapping between the product and the claim elements. The court was willing to accept some level of generality, but not the complete absence of a connection.
Here, the Federal Circuit found that ironSource’s declaration did not address the new limitations at all. The problem was not that the connection was weak; it was that it was missing.
That distinction is subtle but decisive.
The Broader Structural Problem
The case illustrates a recurring issue in PTAB practice. A petitioner can spend significant resources challenging a patent, succeed in invalidating the original claims, and still lose the ability to appeal because the patent owner amends the claims.
The Federal Circuit’s jurisprudence effectively requires petitioners to “refresh” their standing evidence whenever the claim landscape changes.
That requirement is not merely procedural. It can be outcome-determinative.
Charles Gideon Korrell observes that this dynamic creates an asymmetry in post-grant proceedings. Patent owners can strategically narrow claims to preserve validity, while challengers must anticipate and address those amendments to preserve appellate rights. The burden falls entirely on the petitioner to bridge that gap.
Practical Implications
The decision has several concrete implications for parties involved in PGR and IPR proceedings.
First, standing is not static. It must be evaluated based on the claims that exist at the time of appeal. Evidence tied to earlier claims will not carry forward automatically.
Second, declarations supporting standing should be drafted with flexibility in mind. Where possible, they should address not only existing claims but also foreseeable amendments. This is not always practical, but the alternative is risking dismissal.
Third, when a patent owner files a motion to amend, the petitioner should treat that as a trigger to reassess its standing evidence. If the amendments introduce new limitations, the petitioner may need supplemental declarations tying its products or plans to those limitations.
Fourth, reliance on generalized infringement risk is increasingly disfavored. The Federal Circuit continues to demand specificity, particularly where amended claims are narrower than their predecessors.
Charles Gideon Korrell notes that this case reinforces a broader trend in Federal Circuit standing doctrine: the court is willing to dismiss appeals even where there is a clear commercial dispute, if the evidentiary record does not align precisely with the legal requirements.
Strategic Considerations for Petitioners
For companies that routinely challenge patents, the case suggests several strategic adjustments.
One approach is to develop a more detailed record early in the proceeding, including technical analyses that can be adapted to amended claims. While it is difficult to anticipate every amendment, a robust baseline analysis may make it easier to establish the necessary link later.
Another approach is to monitor the amendment process closely and be prepared to supplement the record. This may involve additional declarations or expert input specifically addressing the new claim limitations.
A more aggressive strategy is to challenge the substitute claims directly during the PTAB proceeding, ensuring that the record includes arguments and evidence tied to those claims. While this does not guarantee standing, it reduces the risk of a disconnect.
Charles Gideon Korrell believes that petitioners should treat motions to amend as a critical inflection point, not a secondary issue. The failure to engage with amended claims at a detailed level can undermine not only the merits of the case but also the ability to obtain appellate review.
Implications for Patent Owners
For patent owners, the decision provides a roadmap.
Amending claims is not just a way to preserve validity; it can also be a way to eliminate appellate risk. By introducing limitations that are not clearly tied to the challenger’s activities, a patent owner may be able to create a standing gap.
This is not a guaranteed outcome, and courts will scrutinize the record carefully. But the possibility is real, and ironSource shows that the Federal Circuit is willing to enforce it.
Conclusion
ironSource v. Digital Turbine underscores a fundamental point: in post-grant proceedings, the battle does not end with the Board’s decision. The path to appellate review runs through Article III, and that path can narrow or disappear entirely when claims change.
The case is less about the merits of patentability and more about the mechanics of judicial review. It highlights the importance of aligning factual evidence with the precise legal posture of the case at every stage.
Charles Gideon Korrell notes that the decision serves as a cautionary example of how procedural doctrines can shape substantive outcomes. Even a successful challenge at the Board can unravel if the evidentiary foundation for standing does not evolve alongside the claims.
For practitioners, the takeaway is straightforward: when claims move, your standing evidence must move with them. Anything less risks leaving the appeal without a jurisdictional footing.