On March 22, 2021, the US District Court for the District of New Jersey found a patent’s claims not invalid under the doctrine of obviousness-type double patenting (OTDP) in view of a reference patent from the same patent family, where the challenged patent, due to patent term adjustment (PTA), expires later than the reference patent. See Mitsubishi Tanabe Pharma Corp. v. Sandoz, Inc., No. 3:17-cv-05319-FLW-DEA, 2021 (D.N.J. Mar. 22, 2021). Although this district court decision has not yet been reviewed by the Federal Circuit,¹ it provides support for the position that an earlier-expiring patent is not a proper OTDP reference against its family member expiring later due to additional PTA days.

Background

The doctrine of OTDP is judicially created and “prohibit[s] a party from obtaining an extension of the right to exclude through claims in a later patent that are not patentably distinct from claims in a commonly owned earlier patent.” Eli Lilly & Co. v. Barr Labs., Inc., 251 F.3d 955, 967 (Fed. Cir. 2001). Facing an OTDP challenge of a patent in view of a reference patent, a patentee may choose to file a terminal disclaimer to overcome the OTDP challenge. However, such a disclaimer also forfeits the patent term of the challenged patent extending beyond the term of the reference patent.  

The Federal Circuit has held that a later-issued but earlier-expiring patent can serve as an OTDP reference to invalidate an earlier-issued, later-expiring patent. See, e.g., Gilead Scis., Inc. v. Natco Pharma Ltd., 753 F.3d 1208, 1217 (Fed. Cir. 2014).  

Under 35 U.S.C. § 154(b), a patent holder is entitled to a PTA to compensate for certain delays by the US Patent and Trademark Office (PTO) in issuing the patent. As a result, a patent benefiting from PTA may expire beyond the 20-year term counting from its priority utility application’s filing date under 35 U.S.C. § 154(a)(2). At the same time, other patents of the same family that either receive no or fewer PTA days may expire before the family member patent receiving more PTA days. Under 35 U.S.C. § 156, a patent covering certain subject matter requiring pre-marketing government regulatory review (e.g., review of pharmaceutical products by the Food and Drug Administration) may be entitled to a patent term extension (PTE) intended to compensate the patent holder for time spent during this pre-marketing review.  

The Federal Circuit has considered whether an earlier-filed, earlier-issued patent that has a later expiration date due to PTE was invalid based on the OTDP doctrine. Novartis AG v. Ezra Ventures LLC, 909 F.3d 1367 (Fed. Cir. 2018). The Novartis court held that “obviousness-type double patenting does not invalidate a [patent that] validly obtained PTE” where the patent is “earlier-filed, earlier-issued . . . [and] has the later expiration date, due to a statutorily-allowed” PTE. Id. at 1373. Currently, whether similar reasoning applies to patents from the same family and having different numbers of PTA days remains an open question that has not been addressed squarely by the Federal Circuit.

This question is of particular interest for those patents protecting products having more value toward the end of the patent’s term (e.g., certain pharmaceutical products).  

The District of New Jersey’s Holding That a Patent Cannot Be Used as an OTDP Reference Against a Family Member Having Additional PTA

On March 22, 2021, Chief Judge Wolfson of the District of New Jersey issued an opinion holding that a later-filed, later-issued but earlier-expiring patent cannot serve as an OTDP reference against an earlier-filed, earlier-issued patent of the same family that expires later due to additional PTA.  

In Mitsubishi, the defendant challenged the claims of asserted US Pat. No. 7,943,788 (the ’788 Patent) as invalid under the OTDP doctrine in view of US Pat. No. 8,222,219 (the ’219 Patent). See Mitsubishi at 57. The ’219 Patent is a grandchild application of the ’788 Patent, and the two patents claim priority to the same international patent application filed July 30, 2004. Id. at 3, 4, 62. The two patents thus have the same 20-year patent term counting from the filing date of the international application and running until July 30, 2024. See id. at 3, 58, 62. However, the ’788 Patent received 1,079 days of PTA due to PTO delays during prosecution. Id. at 58. As a result, the ’788 Patent’s expiration date is July 14, 2027—over 27 months after the ’219 Patent expires.² Id. Shown below is a simplified timeline of the terms of the ’788 Patent and the ’219 Patent.

Following a bench trial, the court found that the earlier-expiring ’219 Patent could not be used as an OTDP reference patent against the ’788 Patent.³ Id. at 2, 61.  

The court rejected the defendant’s contention that there is “a bright-line rule” that “the expiration date of a patent governs” OTDP analysis. Mitsubishi at 60. Instead, the court relied on Novartis and found that this case “does not raise the traditional concern with obviousness-type double patenting of a patent owner ‘extending his exclusive rights to an invention through claims in a later-filed patent that are not patentably distinct from claims in the earlier filed patent.’” Id. at 62 (quoting Novartis at 1374). Rather, “absent the PTA granted to the ’788 Patent, both the ’788 Patent and the ’219 Patent would have the same expiration date.” Mitsubishi at 62. Thus, “the granting of a PTA does not present the potential for gamesmanship by inventors to secure a second, later expiring patent for the same invention.” Id. at 62. 

Additionally, the Mitsubishi court distinguished a pre-Novartis decision from the Western District of Michigan, which found that an earlier-expiring family member without a PTA was available as an OTDP reference against a family member that expired later due to PTA days. Magna Electronics v. TRW Automotive Holdings Corp., No. 12-cv-654, 2015 WL 11430786 (W.D. Mich. Dec. 10, 2015). The Michigan court interpreted Natco as “stand[ing] for the simple proposition that a court should look to the expiration dates not the issuance dates to determine if a patent can be used as the prior art patent under the [OTDP] doctrine.” Magna at *11.⁴ The Mitsubishi court stated that “the Federal Circuit has since limited the holding of [Natco]” in the Novartis decision. Mitsubishi at 60. Because Magna pre-dated Novartis, its holding was not found to be persuasive by the Mitsubishi court. Id. at 61 n.44.

Finally and “[p]erhaps more importantly, the Court [wa]s swayed by the Federal Circuit’s observation that ‘a judge made doctrine’ should not be used to ‘cut off a statutorily-authorized time extension,’” i.e., the PTA days provided to a patentee under § 154(b) to compensate for PTO delay in granting a patent. Id. at 63 (quoting Novartis at 1375). 

Implications for OTDP Issues Involving Patents From the Same Family With Different PTA Days

Although the appeal of the Mitsubishi decision has not yet been heard by the Federal Circuit, it provides the District of New Jersey’s application of Federal Circuit OTDP decisions and should be considered in assessing OTDP and potential terminal disclaimers involving patents from the same family with different numbers of PTA days.