Any person associated with the filing and prosecution of a patent application has a “duty of candor and good faith” toward the U.S. Patent and Trademark Office (USPTO). Failure to satisfy this duty can have dire consequences—a court may determine that “inequitable conduct” has occurred and a patent may therefore be found to be unenforceable. Proving that a party has engaged in inequitable conduct, however, has become very difficult over the past few years. So when recently, in Ohio Willow Wood v. Alps South LLC, 2015-1132 (Fed. Cir. Feb. 19, 2016), the U.S. Court of Appeals for the Federal Circuit reached an opinion that inequitable conduct had occurred, many IP attorneys took notice.
For years, inequitable conduct was often argued as a very powerful defense to an accusation of patent infringement. Any error, incorrect statement, or withheld information could form a basis for arguing inequitable conduct. Then, in 2011, the Federal Circuit ruled in Therasense v. Becton, Dickinson & Co., 649 F. 3d 1276 (Fed. Cir. 2011) (en banc). Therasense was a game changer. The Federal Circuit noted that claims for inequitable conduct were being asserted “on the slenderest grounds” and therefore the court “now tightens the standards for finding both intent and materiality in order to redirect a doctrine that has been overused to the detriment of the public.” Therasense established standards for proving inequitable conduct. Intent must be shown by proving that a patent applicant knew of information that they withheld, knew that the withheld information was material, and intentionally withheld the information. Materiality must be shown by determining that the USPTO would not have issued the patent had it known of the withheld information.
