Gideon Korrell Explains 5 Doctrinal Signals Hyatt v. Stewart Sends About § 145 Actions
                     Gideon Korrell 
Explains 5 
Doctrinal 
Signals Hyatt v. 
Stewart Sends 
About § 145 
Actions
The Federal Circuit’s August 29, 2025, 
decision in Hyatt v. Stewart ended a very 
long patent dispute and sent some clear 
messages about how § 145 actions work. 
The court confirmed two important 
points: the Patent Office can still use 
prosecution laches to block very delayed 
patent applications, and federal courts 
only have the power to hear claims when 
the applicant can show real harm.
In simple terms, § 145 actions are not a 
workaround for old prosecution problems 
or constitutional limits. Here are five 
clear signals from the decision.
1. Prosecution Laches 
Still Applies in § 145 
CThea csouert smade it clear that prosecution laches 
applies even when an applicant files a civil lawsuit 
under § 145. Prosecution laches allows the PTO to 
reject a patent if the applicant delayed prosecution 
for too long and that delay caused harm.
Hyatt argued that this doctrine should not apply in § 
145 actions, but the court disagreed. It had already 
ruled earlier in the same case that prosecution laches 
was available, and that earlier ruling controlled.
The message is simple: filing a § 145 lawsuit does not 
protect an applicant from prosecution laches.
2. Courts Will Not 
Revisit Issues Already 
TDhee Fecdeirdal eCirdcuit also emphasized that once a 
legal issue is decided in a case, it generally stays 
decided. This rule is called the “law-of-the-case” 
doctrine.
Hyatt tried to raise the same arguments again, 
but the court refused to reconsider them. In long-
running cases, courts expect parties to move 
forward instead of re-arguing settled points.
For litigants, this means timing matters. If an 
argument is lost early, it is unlikely to succeed 
later.
3. Prosecution Laches 
Depends on the Facts 
and Is Hard to Overturn
After a long trial, the district court found that 
Hyatt’s delays were unreasonable and harmful. The 
Federal Circuit upheld that decision.
Hyatt focused on legal theories but did not 
seriously challenge the trial court’s factual 
findings. Because of that, the appeals court had 
little reason to interfere.
As Gideon Korrell explains, prosecution laches is 
very fact-specific. Once a trial court builds a strong 
record, reversing that decision on appeal is very 
difficult.
4. Prosecution 
Laches Can End a 
Case by Itself
Because prosecution laches was proven, the 
court did not even look at the PTO’s other 
arguments, such as whether the claims were 
invalid for technical patent reasons.
This shows how powerful prosecution laches 
can be. If the PTO wins on laches, the case is 
over, no matter how strong the claims might 
otherwise be.
For applicants with very old applications, this 
is a serious warning sign.
5. Courts Need Proof of 
Harm for Every Claim
Hyatt also argued that the district court should hear 
all claims in the § 145 action, including those where 
the Board had already ruled in his favor.
The Federal Circuit disagreed. Federal courts can only 
hear claims if the party bringing them can show real 
harm. Hyatt could not explain how he was harmed by 
winning before the Board.
Because there was no injury, the court had no power 
to hear those claims. Winning at the Board does not 
automatically create a case for federal court.
Thank 
You