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 ("PTO") during prosecution of a patent application. (1) The duty of candor includes the requirement to submit to the PTO information material to patentability of a pending claim, (2) and a holding of inequitable conduct can be based on the failure to disclose such information to the PTO, if the applicant acted with deceptive intent. (3) Moreover, the duty is owed not only by the applicant, i.e., the named inventor(s), but also by "[e]ach attorney or agent who prepares or prosecutes the application; and [e]very other person who is substantively involved in the preparation or prosecution of the application and who is associated with the inventor, with the assignee or with anyone to whom there is an obligation to assign the application." (4)
In Aventis Pharma S.A. v. Amphastar Pharmaceuticals, the Court of Appeals for the Federal Circuit affirmed the district court's holding that Aventis's asserted patent was unenforceable for inequitable conduct. (5) The conduct in question consisted of the failure to disclose certain information concerning data and associated assertions contained in the patent's specification and in declarations submitted during prosecution. (6) Finding these omissions intentional, and that but for the intentional omissions the patent would likely not have issued, the district court held the patent unenforceable. (7)
Prior to filing its infringement action, Aventis filed an application to reissue its patent. (8) In its reissue application, Aventis expressly disavowed reliance on all arguments proffered during prosecution of the original patent that were based on the data in question. (9) The reissue patent issued one day before the district court's order, and the court extended the judgment of unenforceability of the original patent to the reissue patent. (10) 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." (11)
This article examines the Aventis court's opinion that the judgment of unenforceability of the original patent automatically extended to the reissue patent, and concludes that the court was in error. Section II of the article reviews the facts and critiques the reasoning behind the holding of inequitable conduct in Aventis. Section III considers under what circumstances a patentee should be able to prospectively cure conduct that otherwise would be held inequitable conduct. Section IV examines how the outcome might have been different in Aventis and other cases had the court followed this article's reasoning. Section V briefly summarizes the conclusions drawn.
II. INEQUITABLE CONDUCT IN A VENTIS V. AMPHASTAR
A. The '618 Patent
Aventis markets the drug LOVENOX(r), useful for preventing thromboses (blood clotting) while minimizing the possibility of hemorrhaging, especially during high-risk surgery. (12) Amphastar and Teva each filed an Abbreviated New Drug Application ("ANDA") in order to obtain approval from the Food and Drug Administration ("FDA") to market a generic version of LOVENOX[R]. (13) Consequently, Aventis sued both parties for infringement of U.S. Patent No. 5,389,618 ("the '618 patent"), listed in the FDA's Orange Book for LOVENOX[R]. (14)
The defendants' ANDAs contained a paragraph IV certification (15) alleging, inter alia, that the '618 patent was unenforceable due to inequitable conduct. (16) The assertion of inequitable conduct (with which the district court agreed) was premised on Example 6 of the '618 patent's specification and statements concerning Example 6 by declarant Dr. Andre Uzan. (17) The '618 patent is directed to a composition comprising low molecular weight heparins ("LMWHs"). …