“Should have known” standard is insufficient to establish specific intent, and “deliberate decision to withhold” is required to show specific intent.

A district court found that during prosecution of the patent, the named inventor and his attorney withheld from the Patent and Trademark Office (“PTO”) three material references in two related prosecutions, thereby committing inequitable conduct and making the patent unenforceable. On appeal, the Federal Circuit reversed, ruling that the record contained no evidence of a deliberate decision to withhold those references as required by applicable law.

The Federal Circuit explained that to prove inequitable conduct based on nondisclosure of a reference to the PTO under the new standard set out in Therasense, a defendant must prove that (1) “the patentee acted with the specific intent to deceive the PTO,” and (2) “the non-disclosed reference was but-for material.” To show specific intent, it was insufficient to demonstrate that the reference was known and material; rather, the inventor and his lawyer must have made a “deliberate decision to withhold it.”The record below did not support an inference that the inventor and his lawyer deliberately chose to withhold the references. Appellees cited no specific evidence or communication to show deliberate manipulation. Further, it was a clear error for the district court to rely on the fact that the inventor and his lawyer could not offer a good faith explanation as a basis for inferring deliberate indifference. The record at best, suggested that they knew that the reference was material; but materiality by itself was insufficient to prove a subsequent deliberate decision.

A copy of the opinion can be found here