Litigating Inequitable Conduct after Therasense, Exergen, and the AIA: Lessons for Litigants, Options for Owners

Significant recent judicial and legislative developments have changed the way litigants and counsel need to plan for and litigate inequitable conduct allegations. Exergen and Therasense have heightened the standards for pleading and proving inequitable conduct, respectively, and Congress has expanded the patentee’s post-grant options for preempting or defeating inequitable conduct challenges. Without a doubt, the inequitable conduct litigation landscape has changed. Careful, thorough consideration of all of these developments and their implications is a must for any litigant or counsel faced with or considering asserting a charge of inequitable conduct.This paper discusses these significant recent inequitable conduct-related developments and their combined impact on litigating the defense. It reviews the new judicial standards for pleading and proving inequitable conduct and illustrates their application in recent Federal Circuit and district court decisions. It identifies several areas of debate among the district courts regarding the impact of Therasense and Exergen on pleading inequitable conduct, and summarizes lessons for litigators from recent cases. It discusses the legislature’s recent contribution to the inequitable conduct landscape: the supplemental examination proceeding created by the Leahy-Smith America Invents Act (“AIA”), and considers the options, post-Therasense and the AIA, for patent owners faced with a potential inequitable conduct challenge.