SCOTUS Must End Prosecution Laches Before It Becomes a Patent Killing Machine

The Supreme Court should grant certiorari in Hyatt v. Squires—a case it is scheduled to consider later this week—and finally put an end to prosecution laches in patent law. Not limit it. Not cabin it. Not send the Federal Circuit back to craft yet another multi-factor balancing test that will inevitably metastasize into a litigation weapon. The Supreme Court must end prosecution laches once and for all, period.

The doctrine of prosecution laches is both illegitimate and indefensible. That it is applied against patent applicants and patent owners who complied with every statute, every regulation, and every deadline imposed by Congress and the United States Patent and Trademark Office (USPTO) makes it practically un-American. There is nothing equitable about punishing a patent owner for doing exactly what the law allowed. There is nothing noble about transforming a fully compliant patent prosecution history into a post hoc basis for forfeiture. And there is nothing remotely consistent with the Patent Act, the Supreme Court’s own laches precedent, or the Constitution’s command to promote the progress of science and the useful arts when courts use laches to nullify patent rights after the fact.

For years, prosecution laches was treated by many as a quirky, rare, submarine-patent relic. That was always foolish and wrong, but understandable. The doctrine was born out of cases involving pre-GATT [General Agreement on Tariffs and Trade] patent term rules, where patent term ran from issuance and applicants could theoretically extend patent life by delaying issuance. But that world no longer exists. Since the 1995 GATT amendments, patent term runs from filing, not issuance. The supposed submarine-patent concern that animated the modern revival of prosecution laches is obsolete.

Yet, the Federal Circuit has not only kept the doctrine alive; it has expanded it. Worse, in Hyatt v. Hirshfeld and Hyatt v. Stewart, the Federal Circuit created a six-year presumption that a patent prosecution delay is unreasonable, inexcusable, and prejudicial. That is not merely wrong, it is an institutional power grab. It replaces the statutory presumption of validity with a judicially manufactured presumption of unenforceability, which is precisely contrary to the Patent Act itself.

The industry has convinced itself that this is just an issue for Gil Hyatt. And ignoring the fact that Hyatt’s applications were caught up in SAWS and the USPTO refused to examine or allow them for several decades, the public has seemingly believed that the doctrine—no matter how wrong it is—will be limited to Hyatt and his pre-GATT patent applications that the USPTO refused to examine. But now comes the latest proof that this issue demands immediate Supreme Court intervention: the District of Delaware’s June 16, 2026 memorandum order in the GSK vaccine litigation against Pfizer/BioNTech and Moderna.

Prosecution Laches Becomes a Strategic Weapon

In Glaxosmithkline Biologicals SA v. Pfizer Inc., and related cases involving BioNTech and Moderna, the district court denied GSK’s motions to dismiss prosecution laches counterclaims and strike related affirmative defenses. To be clear, this was a pleading-stage decision. The court was not holding that GSK committed prosecution laches. The court was not making a final finding of unenforceability. The court was applying the motion-to-dismiss standard and accepting well-pleaded allegations as true. But that is precisely why the decision matters.

The operational problem with prosecution laches is not merely that a patent might ultimately be held unenforceable. The immediate problem is that an accused infringer can plead prosecution laches, survive dismissal, impose costly discovery, create settlement leverage, and inject uncertainty into patent assets that are supposed to be presumed valid after having been prosecuted in compliance with the Patent Act and USPTO rules.

This makes prosecution laches a strategic weapon. And the marketplace has figured out that because of the overbroad language of the Federal Circuit, the doctrine is not limited to Gil Hyatt, or pre-GATT patents. Prosecution laches is now a weapon that every patent owner with a patent that took longer than six-years to obtain will have to deal with even if their patents are post-GATT.

In the Pfizer/BioNTech (PBNT) portion of the case, the defendants alleged that GSK pursued broader claims after public information regarding Pfizer and BioNTech’s COVID-19 vaccine became available. According to the order, PBNT argued that GSK took nearly a decade after the provisional applications were filed to begin pursuing broader claims and that seven of the eight patents at issue were filed on or after April 1, 2020, shortly after Pfizer and BioNTech announced they were co-developing an mRNA vaccine for COVID-19. The court held that, accepting the allegations as true, PBNT had plausibly alleged unreasonable and inexcusable delay based on a totality of the circumstances. The district court also similarly held that PBNT plausibly alleged prejudice, relying on allegations that PBNT invested time and resources in developing the accused products during the period of alleged delay and developed the first COVID-19 vaccine to combat COVID-19.

The Moderna analysis was materially similar. Moderna alleged that GSK intentionally and inexplicably rewrote claims and delayed publicly disclosing claim content and application disclosures. The court concluded that Moderna plausibly alleged unreasonable and inexcusable delay. The court further held that Moderna plausibly alleged prejudice because it allegedly invested nearly 10 years and extensive resources developing its mRNA and LNP platform technologies while the public disclosures were directed elsewhere. The court emphasized that there are no bright-line rules governing prosecution laches and that courts must evaluate the totality of the circumstances.

‘Totality of the Circumstances’ Is Not a Rule of Law

That phrase—“totality of the circumstances”—is where certainty goes to die. And the patent system cannot function on after-the-fact judicial vibes based on a totality of the circumstances that results in a presumption that a patent—any patent—is unenforceable upon issuance.

When the statutory criteria are satisfied, the Patent Act says the USPTO shall issue a patent.

And let us not forget that, in 2017, the Supreme Court in SCA Hygiene Prods. Aktiebolag v. First Quality Baby Prods., LLC already addressed the issue of laches in the patent context, reversing the Federal Circuit. And more pertinent perhaps, in that decision the Supreme Court explained that for laches to play any role in the law it must be to fill gaps left by Congress in legislation. But here, where there is a statute that prescribes specific periods of time within which the patent applicant must act, it is simply inappropriate for laches to be used to support equitable unenforceability where the applicant operated within all applicable deadlines.

Said another way, if there is a statute that gives an actor a certain time within which to act, it cannot possibly be inequitable for the actor to have taken the length of time the statute gives to act. And this, of course, makes sense. Acting within given time periods allotted by the law is not wrong—it is specifically allowed and cannot possibly be inequitable.

Katznelson Data Destroys the ‘Limited Importance’ Argument

The USPTO has argued that Hyatt presents a question of limited and diminishing importance because most pending applications and patents in force postdate the 1995 change in patent term. That contention sounds plausible, but only until one looks at the data.

Ron Katznelson has done that work. His June 12, 2026 article titled Fact-Checking the Assertions of the Parties in Hyatt v. Squires identifies at least 424 federal cases in which defendants asserted prosecution laches after Hyatt I was decided by the Federal Circuit in 2021. These 424 cases involve 1,786 patents in suit, all of which were filed after 1995. That is not limited. That is not diminishing. That is a litigation trend that goes well beyond Hyatt, well beyond GSK, Pfizer and Moderna, and something that the patent owning industry should see as an existential threat.

And it is not merely a trend in district court litigation. Katznelson also identifies prosecution laches assertions at the International Trade Commission (ITC), which should alarm anyone who cares about protecting domestic industry in the United States. If prosecution laches becomes a routine ITC defense, foreign importers will have another tool to neutralize U.S. patents protecting domestic industries, which will dramatically undercut the entire rationale for the ITC to have any kind of patent jurisdiction in the first place.

Katznelson’s data also shows why the Federal Circuit’s six-year presumption is reckless. According to his analysis, 30% of U.S. utility patents issued more than six years after earliest priority, and 36% of utility patents asserted at the ITC issued more than six years after earliest priority. At the 10-year mark, asserted ITC patents are also overrepresented compared with all issued utility patents.

That is exactly what one would expect. Important technologies often require continued prosecution, continuation practice, claim refinement, evolving commercial embodiments, regulatory development, technical iteration, and portfolio strategy. And none of that changes whether the originally filed patent application fairly describes the innovation for which a patent ultimately was granted years later. Sophisticated patent owners do not file once, accept whatever narrow claims happen to issue first, and stop. They build portfolios. They prosecute continuations. They claim disclosed inventions from multiple angles. They respond to evolving examiner positions. They use the tools Congress provided.

And, of course, let’s not turn a blind eye to the fact that, to get the claim scope you deserve from a patent examiner who often sees themselves as the gatekeeper, it is typically necessary to pursue a continuation strategy that over time builds the patent portfolio to the level that should have been warranted from the start but was denied. Simply stated: you cannot ignore the role examiners play in not granting the protection and scope deserved and blame patent owners for having the audacity to keep seeking the level of protection the law says should have been theirs from the start.

The Federal Circuit has now put all of this at risk. This is precisely why courts are not supposed to legislate. By taking it upon themselves to overwrite the statute, they are on the brink of throwing the entire patent system under the bus.

Hyatt Is the Vehicle the Supreme Court Needs

Hyatt v. Squires squarely presents the question the Supreme Court must answer: can the equitable doctrine of prosecution laches be used to deny a patent to an applicant who complied with all the Patent Act’s timing requirements? There are no extraneous questions or issues to deal with. The presentation is clean and the resolution critically important not only for Hyatt, but for the industry as a whole.

Based on recent Supreme Court precedent, as well as logic, the question should answer itself. If an applicant complied with every statutory timing requirement, there is no unreasonable delay as a matter of law. Acting within the time allowed by law cannot be inequitable merely because a court later dislikes the duration of the process. Hyatt gives the Supreme Court a clean opportunity to enforce that line, and they should take the opportunity presented and allow no further mischief to override common sense.

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Author: amanalang