Key Points

• The District of New Jersey allowed generic defendants in a Hatch-Waxman case to assert inequitable conduct, unclean hands, and antitrust claims based on an alleged scheme to fraudulently alter patent inventorship and extend the life of a patent.
• In a novel ruling, the Court applied the infectious unenforceability doctrine prospectively and extended Walker Process antitrust liability beyond traditional patent-procurement fraud to reach post-issuance misconduct before the PTO.
• Despite an alleged 14-month delay, the Court found defendants diligent in moving for leave to amend and the proposed amendments non-futile, permitting addition of fraud and antitrust theories.

In a ruling with significant implications for Hatch-Waxman litigation, a federal magistrate in the District of New Jersey granted generic drug manufacturers' motion to amend their affirmative defenses, counterclaims, and invalidity contentions to include allegations of inequitable conduct, unclean hands, and antitrust violations.

The ruling by U.S. Magistrate Judge Tonianne J. Bongiovanni allows defendants to pursue the theory that plaintiffs and their named inventor purportedly engaged in a scheme to fraudulently extend the life of a key patent covering the blockbuster oncology drug Lynparza® (olaparib).

Background

The case involves a patent infringement action brought by AstraZeneca and related entities against a group of generic defendants — Cipla, Natco Pharma, Sandoz, and Zydus — that had filed Abbreviated New Drug Applications (ANDAs) seeking FDA approval for generic versions of Lynparza® tablets. Among the patents at issue is U.S. Patent No. 8,859,562 (the '562 patent), which does not expire until 2031. Dr. Thomas Helleday is the sole named inventor of the single claim of the '562 patent.

Defendants alleged that the '562 patent's single claim is obvious over two earlier patents also invented by Dr. Helleday — U.S. Patent Nos. 7,351,701 and 7,531,530 — both of which expired in 2024. Under the doctrine of obviousness-type double patenting (OTDP), the '562 patent should have a term no longer than the earlier patents. However, in 2024, Dr. Helleday filed petitions with the U.S. Patent and Trademark Office (PTO) to remove himself as an inventor from the two earlier patents. Plaintiffs then argued that, absent common inventorship, the OTDP defense could not be sustained.

Defendants contend that Dr. Helleday's removal of himself as an inventor was a fraudulent act — carried out in coordination with AstraZeneca — with the sole purpose of saving the '562 patent from invalidity and extending its enforceable life by seven years.

Diligence in Moving to Amend

The Court first addressed defendants’ motion to amend, reviewing the standards under Fed. R. Civ. P. 15(a) and Local Patent Rule 3.7, applicable to pleadings and invalidity contentions, respectively. The Court rejected plaintiffs’ argument that defendants had unduly delayed in seeking leave to amend, finding that defendants acted diligently. Plaintiffs argued that the documents giving rise to defendants’ proposed amendments were publicly filed in July 2024, yet defendants waited until September 29, 2025 to file their motion.

However, the Court observed that plaintiffs did not produce the complete file histories until December 2024, and their validity contentions disclosing the inventorship change were not served until January 2025. Defendants promptly began pursuing party and third-party discovery in February 2025, and only moved to amend after deposing Dr. Helleday in August 2025 and receiving third-party production from Pfizer. The Court emphasized that, given the heavy burden of proving inequitable conduct, it was reasonable for defendants to investigate thoroughly before moving to amend.

Moreover, the Court found that when plaintiffs produced documents regarding the inventorship change, “[d]efendants immediately pursued discovery from [p]laintiffs” and “swiftly took steps to investigate the inventorship change[.]” The Court further found there was no undue prejudice to plaintiffs because there was sufficient time to conduct the discovery, and although fact discovery had closed, there was still a pending motion to compel. Further, at the time the motion was filed, expert discovery had just begun, and no trial had been scheduled.

The Court then assessed whether the proposed amendments were futile, noting the heavy burden was on the party opposing the amendment.

Inequitable Conduct

The Court found that defendants sufficiently alleged all elements of an inequitable conduct claim under Rule 9(b)'s heightened pleading standard, identifying the specific "who, what, when, where, and how" of the alleged material misrepresentation before the PTO. The Court found the facts defendants alleged, when taken as true, supported a reasonable inference that Dr. Helleday and plaintiffs knew Dr. Helleday was making a material misrepresentation when he filed the correction of inventorship and it was undertaken with the specific intent to deceive the PTO.

The Court further found the infectious unenforceability doctrine could plausibly extend the taint from the '701 and '530 patents to the '562 patent. In particular, the Court reasoned that there was "an immediate and necessary relation" between the alleged fraud and the equity sought by plaintiffs (i.e., the enforcement of the '562 patent) even though the '562 patent issued years before the alleged misconduct, noting that “no direct linkage between the inequitable conduct at issue and the prosecution of the patent-in-question” is required.

The Court acknowledged the theory was novel but noted it "fits within the bounds of the infectious unenforceability doctrine."

For substantially the same reasons, the Court found the unclean hands defense non-futile.

Antitrust Violations

Defendants also sought to add an antitrust claim based on Walker Process fraud, which requires “higher threshold showings of both materiality and intent than are required to show inequitable conduct” and requires establishing the other elements to an antitrust injury under Section 2 of the Sherman Act.

“Walker Process” claims refer to the U.S. Supreme Court’s holding in the seminal case Walker Process Equipment, Inc. v. Food Machinery & Chemical Corp., 382 U.S. 172 (1965), including that enforcement of a fraudulently procured patent may serve as grounds for an antitrust claim under the Sherman Antitrust Act.

Here, perhaps most notably, the Court extended the reach of Walker Process fraud beyond its traditional application in procurement of a patent by fraud (which was not alleged here) to encompass situations where a “patentee procured something of value through actual fraud upon the PTO.” As the Court summarized, that is what defendants allege happened: “[p]laintiffs and Dr. Helleday knowingly and willfully misrepresented that Dr. Helleday was not an inventor of the ‘701 and ‘530 patents with an intent to deceive the PTO so that the PTO would remove Dr. Helleday as an inventor of the ‘701 and ‘530 patents for the purpose of saving the ‘562 patent from invalidity for OTDP over those patents in this litigation.” The Court also found that attorneys’ fees incurred in defending the patent infringement suit could constitute antitrust injury, citing the Federal Circuit's holding in TransWeb, LLC v. 3M Innovative Properties Co., 812 F.3d 1295 (Fed. Cir. 2016). Thus, defendants’ allegations, when taken as true, were not futile.

Discovery Dispute

The Court also granted in part defendants' pending informal motion to compel discovery, ordering plaintiffs to produce documents responsive to several requests for production related to the inventorship change and the OTDP defense, but ruling that plaintiffs need not produce information in response to certain categories that were overbroad and burdensome.

Paul W. Kalish and Jonathan J. Madara are members of the IP Litigation team in Fox Rothschild’s Princeton, NJ office and write about patent litigation decisions in the District of New Jersey. Contact Paul at pkalish@foxrothschild.com or 609.895.6751 and Jonathan at jmadara@foxrothschild.com or 609.844.7428.

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