25 Years of CAFC Inequitable Conduct Jurisprudence

Inequitable conduct allegations seem to appear in almost every patent infringement case litigated in the last few years. Trial courts and practitioners should take note of recent Court of Appeals for the Federal Circuit ('CAFC') cases that shed light on the importance of particular fact patterns that may influence determinations of inequitable conduct. Almost 25 years ago, the CAFC began its inequitable conduct jurisprudence by holding that patents are generally unenforceable if procured amidst inequitable conduct in the seminal case of Kingsdown Med. Consultants, Ltd. v. Hollister, Inc., 863 F.2d 867, 872 (Fed. Cir. 1988) (portions en banc). This jurisprudence held that a defendant must show: 1) material act(s) by the plaintiff, and 2) the plaintiff's intent to deceive the PTO to prove an inequitable conduct defense. Upon a showing of inequitable conduct, the court may hold the claims of the patent unenforceable. By balancing the levels of materiality and intent, with a greater showing of one factor allowing a lesser showing of the other, the court will determine whether the inequitable conduct exists. Specifically, four recent CAFC decisions: McKesson Info. Solutions, Inc. v. Bridge Med., Inc., 487 F.3d 897 (Fed. Cir. 2007); eSpeed, Inc. v. BrokerTec, USA, L.L.C., 480 F.3d 1129 (Fed. Cir. 2007); Cargill Inc. v. Canbra Foods, Ltd., 476 F.3d 1359 (Fed. Cir. 2007); and Dippin' Dots, Inc. v. Dots of Fun, Int'l, 476 F.3d 1337 (Fed. Cir. 2007), shed light on the CAFC's current inequitable conduct jurisprudence and provide insight into how certain conduct may be interpreted by the court today.