The Federal Circuit Revisits Inequitable Conduct: How the Best-Laid Schemes of Mice and Men Go Often Awry¹

Gino Cheng

Winston & Strawn LLP

On May 25, 2011, in the fragmented en banc Therasense opinion, the Federal Circuit set forth a new, heightened test requiring that a prior art reference, knowingly withheld by the applicant, be "but for" material to the patent’s issuance in order to constitute inequitable conduct.² The pro-patentee decision tightened the standards for finding the materiality of withheld information and the applicant’s specific intent to deceive the patent office, the result of which would render the obtained patent unenforceable. On the heels of the en banc decision, in June of 2011, the panel in American Calcar I remanded the inquiry of inequitable conduct to the district court for more detailed determinations of materiality and intent under the new standard.³ American Calcar II would be heard by the Federal Circuit in 2014,⁴ with Chief Judge Prost and Judges Wallach and Newman presiding. As discussed in my previous article, the split decision fell along doctrinal battle lines,⁵ with Judge Newman from the Therasense majority finding herselfin the minority.⁶ More recently, in Regeneron, again outnumbered by Chief Judge Prost and Judge Wallach, Judge Newman reprised her role from American Calcar II and penned another dissent that criticizes the shift away from the strictures of the Therasense framework. Does the same panel that decided American Calcar II merely retread the same jurisprudential ground, and if not, where does Regeneron leave patent practitioners?

BACKGROUND