In Apotex, Inc. v. UCB, Inc. the Federal Circuit affirmed the Southern District of Florida’s holding that Apotex’s patent (U.S. Patent No. 6,767,556) is unenforceable for inequitable conduct.  This marks a rare instance of success for the defense after the Federal Circuit’s Therasense decision raised the bar on the materiality and intent requirements necessary to show inequitable conduct. It also illustrates the kind of activity that crosses the line from zealous advocacy to misrepresentation that can support the inequitable conduct defense.

The ʼ556 patent was directed to a process of manufacturing moexipril tablets—an ACE inhibitor used to treat hypertension.  Specifically, the process consisted of creating relatively stable moexipril magnesium tablets by reacting moexipril with an alkaline magnesium compound.  During prosecution, the patent received three obviousness rejections, all of which were overcome essentially by arguing that combinations of prior art did not teach a reaction, but merely a combination of moexipril and an alkaline stabilizing agent.

The Federal Circuit held that clear and convincing evidence demonstrated that Dr. Bernard Sherman, founder and chairman of Apotex and inventor of the ʼ556 patent, engaged in material misconduct.  Dr. Sherman made affirmative misrepresentations, including that at least one of the accused products, which was prior art to the ʼ556 patent, was not made according to the claimed process, when he knew that it was.  Dr. Sherman also mischaracterized a key prior art article by stating that it primarily disclosed a combination, rather than a reaction, and he included examples of experiments in the specification that never were conducted.  Furthermore, and particularly inexcusable to the Court, Dr. Sherman hired an expert to write a declaration supporting his misrepresentations, but the expert was given only select facts, which shielded him from the truth of the prior art.  But-for these misrepresentations, the Court found that the patent would not have issued.

The Court also found that clear and convincing evidence established Dr. Sherman’s intent to deceive the PTO.  Apotex argued that Dr. Sherman was merely advocating for a particular interpretation of the prior art, but the Court stated that his statements were factual in nature and contrary to true information he had in his possession: “He knew enough to recognize that he was crossing the line from legitimate advocacy to genuine misrepresentation of material facts.”

The Therasense case raised the bar on the materiality and intent requirements necessary to show inequitable conduct, but this case shows that with particularly egregious behavior the defense remains available.  Indeed, the Court noted that Dr. Sherman’s actions came close to the type of misconduct that Therasense said could justify a finding of inequitable conduct without showing but-for materiality.  Zealous advocacy of an interpretation of the prior art still is permitted, but one must be careful to not cross the line from interpretation to misrepresentation.