Gideon Korrell Highlights 5 Drafting Mistakes That Sank the Claims in Brita LP v. ITC
                     Gideon Korrell 
Highlights 5 
Drafting 
Mistakes That 
Sank the Claims 
in Brita LP v. 
ITC
The Federal Circuit’s October 15, 2025, 
decision in Brita LP v. ITC sends a clear 
message: if you claim a broad invention 
based on performance, your patent 
must clearly show how to achieve that 
performance across the entire claim 
scope.
In this case, the court agreed with the 
International Trade Commission that 
Brita’s patent failed the written 
description and enablement 
requirements of Section 112. The 
claims were simply broader than what 
the patent actually taught.
Mistake 1: Claiming 
Many Filter Types, 
Teaching Only One
Every working example in the patent that 
met the FRAP requirement used carbon-
block filters. No other filter type worked. 
Mixed media filters were tested and failed. 
Other types were mentioned, but never 
shown to succeed.
The court held that this showed possession 
of only one solution, not the entire group 
claimed. Under long-standing law, including 
Ariad v. Eli Lilly, a patent must show that the 
inventors actually had what they claimed.
Mistake 2: Teaching 
That Other Filters 
TDheo pnro’btle mW woenrtk further. The patent 
didn’t just fail to explain how other filters 
could work it explained why they didn’t 
work. The specification described 
prob1lems with granular and mixed media 
filters and showed test results where they 
failed to meet FRAP.
Inventors even testified that they switched 
to carbon blocks because other media 
could not solve the lead problem. That 
made it hard to argue that the invention 
covered all filter types.
Mistake 3: Relying 
on Broad Brita argued that the claims 
Statements Instead and general statements saying FRAP was 
of Details “independent of the 
embodiment” were enough. 
The court rejected that.
Claims alone cannot prove 
possession, and hopeful 
language cannot replace 
technical explanation, 
especially when the rest of the 
patent says carbon blocks are 
“unique.”
Mistake 4: No Clear 
Path to Enable Other 
Filters
Enablement failed for the same reason. The 
FRAP formula involved interdependent 
variables, and experts testified that changing 
one factor unpredictably affected others. 
While the patent подробно explained carbon-
block filters, it gave no guidance for making 
other filter types meet the FRAP requirement, 
leaving skilled engineers to rely on trial and 
error. The court also rejected Brita’s claim that 
filtration is a predictable field, citing Amgen v. 
Sanofi for the principle that results-based 
claims require clear teaching, not guesswork.
Mistake 5: Letting 
Testing Data 
Undermine the 
Claims
Brita’s detailed testing did not help. 
Instead, it showed that only carbon-
block filters worked. By documenting 
failures of other designs, the patent 
weakened its own claim to a broad 
invention.