Decision raises the threshold to prove inequitable conduct in patent litigation

The Federal Circuit’s en banc decision in Therasense v. Becton raises the threshold for proving inequitable conduct as a defense to patent infringement. “To prevail on a claim of inequitable conduct, the accused infringer must prove that the patentee acted with the specific intent to deceive the PTO.” The Federal Circuit explained that, to prove specific intent to deceive, requires an 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.”

Therasense (now Abbott) filed a patent application for disposable blood glucose test strips for diabetes management. During the 13 years of prosecution, the application received multiple rejections for anticipation and obviousness. To overcome these rejections, Abbott submitted an affidavit from its Director of Research and Development, and the application finally issued as U.S. Patent No. 5,820,551 (the ‘551 Patent).