Prospectively Curing Inequitable Conduct Through Reissue: Reconsidering a "Well-settled Principle"

Daniel A. Klein, Millennium Pharmaceuticals, Inc.: The Takeda Oncology Company

Abstract

CURRENTLY IN PRESS WITH THE SANTA CLARA COMPUTER & HIGH TECHNOLOGY LAW JOURNAL. PLEASE USE THE CHTLJ CITATION TO REFERENCE THIS ARTICLE WHEN IT BECOMES AVAILABLE.

Inequitable conduct is an equitable doctrine that renders a patent unenforceable upon a finding that the patentee has breached the duty of candor and good faith owed to the U.S. Patent and Trademark Office during prosecution of a patent application. In Aventis Pharma S.A. v. Amphastar Pharmaceuticals, the Court of Appeals for the Federal Circuit held that Aventis’s asserted patent was unenforceable for inequitable conduct. However, prior to filing its infringement action, Aventis had filed an application to reissue its patent, and in its reissue application had disavowed reliance on the very statements on which the assertion of inequitable conduct was based. The reissue patent issued prior to the trial court’s judgment, but the court simply extended the judgment of unenforceability of the original patent to the reissue patent. The Federal Circuit affirmed, citing the “well-settled principle” that a reissue proceeding cannot rehabilitate a patent held to be unenforceable due to inequitable conduct. The Aventis court dispensed with the significance of the reissue patent with no more than a footnote. However, a careful reading of the opinions cited by the court reveals that the majority improperly relied on dicta to announce a principle broader than the precedent warrants. The Federal Circuit’s statements on this issue in earlier, uncited opinions similarly demonstrate a misreading of precedent. Moreover, not only is the public interest served by allowing patentees to prospectively cure “inequitable” conduct in post-grant proceedings, but the Aventis rule may actually encourage behavior the law should work to dissuade. Consideration of the timing of relevant events leads to a framework in which patentees are permitted to employ reissue to cure conduct—specifically, omissions and misrepresentations—that would otherwise be judged inequitable conduct, under limited circumstances. Application of the proposed analysis might have lead to a different result in Aventis and other cases, and should lead to a more just result for both the public and the patentee in future actions.