IP Law Daily Inequitable conduct counterclaim proceeds in Depomed drug-delivery patent dispute
Friday, June 30, 2017

Inequitable conduct counterclaim proceeds in Depomed drug-delivery patent dispute

By Linda O’Brien, J.D., LL.M.

Purdue Pharma set forth sufficient allegations to pursue a counterclaim based on inequitable conduct in response to Depomed’s patent infringement suit, which challenged Purdue’s manufacture and sale of the pain reliever OxyContin, the federal district court in Trenton, New Jersey, has ruled. Depomed’s motion to dismiss was denied. Purdue failed, however, to set forth factual allegations to support an affirmative defense of patent misuse (Depomed, Inc. v. Purdue Pharma L.P., June 28, 2017, Cooper, M.).

Depomed owned U.S. Patent No. 6,340,475 ("the ’475 patent") and U.S. Patent No. 6,635,280 ("the ’280 patent"), both of which were directed to a controlled-release oral dosage form of a soluble drug and a method of using that dosage form.

In 2013, Depomed sued Purdue Pharma and two of its manufacturing affiliates (collectively, "Purdue") for the infringement of the ’475 and ’280 patents. According to Depomed, Purdue’s manufacture and sale of OxyContin®—an oral, controlled-release formulation of the pain reliever oxycodone—infringed each of the patents in suit.

Purdue filed three petitions requesting inter partes review (IPR) of the asserted claims, asserting that the claims were obvious over a prior art publication and other references. The Patent Trial and Appeal Board (PTAB) instituted IPR, and the infringement litigation was stayed. The Board found that Purdue had failed to establish the obviousness of the challenged claims. Subsequently, the Board’s decision rejecting Purdue’s invalidity assertions was affirmed on appeal.

In response to Depomed’s complaint, Purdue filed a counterclaim that included allegations of inequitable conduct by the inventor of the patents-in-suit, Jenny Louie Helm, and an affirmative defense of patent misuse. Before the court was Depomed’s motion to dismiss the counterclaim and affirmative defense.

Material misrepresentations and omissions. The court found that, in its answer and counterclaim, Purdue provided sufficient details to meet the particularity requirements of Federal Rule of Civil Procedure 9(b). To plead inequitable conduct with the requisite particularity under Rule 9(b), the pleading must identify the specific "who, what, when, where, and how" of the material misrepresentation or omission that was committed before the PTO.

In this case, Purdue alleged that Depomed and Helm had made material misrepresentations to the PTAB during the IPR proceedings by misrepresenting the number of years of research that was taken to develop an embodiment of the claimed invention, in order to avoid an obviousness determination. Specifically, Purdue identified numerous paragraphs—in Helm’s declaration—that allegedly misrepresented the time and research that was necessary to arrive at an embodiment that fell within the scope of the claims. Based on those allegations, it was reasonable to infer that Helm and Depomed had intended to paint an incomplete or misleading picture for the Board. The alleged facts supported a reasonable inference that a specific individual "knew of the withheld material information or misrepresented this information with a specific intent to deceive" the PTO, the court explained.

Prior inconsistent statements. Purdue could not to show that the defendants’ failure to produce, during the IPR proceedings, the inconsistent interrogatory response and sworn verification from a prior litigation was done with a specific intent to deceive the PTO. According to the court, Purdue admitted that Depomed had produced the interrogatory response and verification to Purdue prior to the stay. Depomed’s compliance prior to the IPR proceeding could not serve as a basis for a claim of inequitable conduct.

Patent misuse. Finally, the court found that Purdue did not present any additional facts or theories that could plausibly support an affirmative defense of patent misuse. Purdue’s contention that the claims of the ’475 and ’280 patents were unenforceable because Depomed was attempting to impermissibly broaden the temporal scope of the patent grant with an anticompetitive effect by alleging infringement after the expiration of the patents was rejected. The injunction Depomed sought was limited to the life of the patents, the court explained, and the owners of expired patents had six years after the expiration date to pursue infringement claims. Therefore, the assertion of a patent right provided by statute could not serve as the basis for a claim that a patentee had attempted to expand the scope of its patent in an anticompetitive manner, the court concluded.

The case is No. 3:13-cv-00571-MLC-TJB.

Attorneys: Keith J. Miller (Robinson Miller LLC) for Depomed, Inc. Liza M. Walsh (Walsh Pizzi O'Reilly Falanga LLP) for Purdue Pharma L.P. and The P.F. Laboratories, Inc.

Companies: Depomed, Inc.; Purdue Pharma L.P.; The P.F. Laboratories, Inc.

MainStory: TopStory Patent NewJerseyNews

Back to Top

Interested in submitting an article?

Submit your information to us today!

Learn More