but-for materiality

A Tougher Standard for Proving Inequitable Conduct?

June 8, 2011

In a 6–1–4 decision, an en banc Federal Circuit in Therasense, Inc. v. Becton, Dickinson and Company tries to cure the “plague” of inequitable conduct pleadings by raising the bar for proving that alleged bad acts were material to patentability and that the patentee undertook the alleged bad acts with intent to deceive the Patent and Trademark Office.

The court now rejects the previous “sliding scale” approach that allowed strong evidence of materiality to compensate for weak evidence of intent to deceive (and vice-versa), and requires the accused infringer to prove both elements — intent and materiality — by clear and convincing evidence.

For the element of intent to deceive, the Federal Circuit now demands evidence of a “deliberate decision” to deceive the Patent Office.  Focusing on the failure to submit prior art material to patentability, the court held that “the accused infringer must prove by clear and convincing evidence that the applicant knew of the reference, knew that it was material, and made a deliberate decision to withhold it.”

For the element of materiality, the Federal Circuit now demands evidence of “but-for materiality.”  Stated differently, the court must find that, but for the deception, the Patent Office would not have allowed the claim.  “In making this patentability determination, the court should apply the preponderance of the evidence standard and give claims their broadest reasonable construction.”  Yet, the court identified a major exception [to proving but-for materiality] in cases of “affirmative egregious misconduct”.

Please click here for a link to the opinion, and please contact our attorneys to further discuss the Therasense opinion.