Extending Ezra: Federal District Court Declines To "Cut Off" Patent Term Adjustment In View Of Alleged Obviousness-Type Double Patenting In Mitsubishi v. Sandoz

• Published date: 13 August 2021
• Subject Matter: Intellectual Property, Food, Drugs, Healthcare, Life Sciences, Patent, Biotechnology & Nanotechnology
• Law Firm: Wolf, Greenfield & Sacks, P.C.
• Author: Mr Eric Greenwald

(Co-authored by Anne Weeks)

In Mitsubishi Tanabe Pharma Corp. v. Sandoz, Inc., the District Court for the District of New Jersey considered whether a patent receiving patent term adjustment (PTA) may be invalidated for obviousness-type double patenting by a later-issuing, earlier-expiring patent in the same family.

Background

Mitsubishi Tanabe Pharma Corp. (MTPC), Janssen, and Cilag sued Zydus and other drug manufacturers in the District of New Jersey alleging patent infringement based on Abbreviated New Drug Applications ("ANDAs") filed by the defendants that sought approval to market generic versions of MTPC's Invokana products, which treat diabetes. MTPC asserted U.S. Patent Nos. 7,943,788 ("the '788 patent"); 8,222,219 ("the '219 patent"); and 8,785,403. Zydus filed a counterclaim alleging that MTPC's asserted patents were invalid for obviousness and obviousness-type double patenting. On March 22, 2021, the District Court found that MTPC's patents were not invalid for obviousness or obviousness-type double patenting.

Obviousness-Type Double Patenting

Obviousness-type double patenting is a judge-made doctrine designed to prevent applicants from obtaining additional protection for claims that are not patentably distinct from the claims of an "earlier" US patent or application owned by the applicant (i.e., in which the applicant has an ownership interest). This doctrine is intended to prevent unlawful extensions of the limited patent "monopoly." The Federal Circuit has addressed obviousness-type double patenting on two recent occasions. In Gilead Sciences, Inc. v. Natco Pharma Ltd.,¹ the Federal Circuit addressed whether a later-issuing, but earlier-expiring, patent can properly be used as a double patenting reference against the other patent. The court held that it could, because to hold otherwise would allow applicants to "game" the patent system to extract additional patent exclusivity for claims that are obvious over a reference patent.

However, the Federal Circuit limited the "Gilead rule" in Novartis AG v. Ezra Ventures LLC,² where it found that a challenged patent that expires after a later-filed, later-issued reference patent due to a patent term extension (PTE) cannot be invalidated for obviousness-type double patenting by that reference patent. In so finding, the court noted that, unlike the case in Gilead, the fact pattern in Ezra did not create the same potential for "gamesmanship" relating to structuring of priority dates by the applicant...