Non-statutory, or obviousness-type, double patenting (“ODP”) is a judicially created doctrine that prohibits an inventor from effectively extending the monopoly on a patented invention by applying for a later patent with claims that are not “patentably distinct” from the claims in the earlier patent.  The core principle behind the doctrine is that “an inventor must fully disclose [the] invention and promise to permit free use of it at the end of [the] patent term.”  See Novartis Pharmaceuticals Corp. v. Breckenridge Pharmaceutical (“Breckenridge”).  “Prohibiting double patenting prevents a patentee from obtaining sequential patents on the same invention and obvious variants” to improperly extend patent protection beyond the “statutorily allowed patent term of that invention.”  Id.

In Gilead Sciences, Inc. v. Natco Pharma Ltd., the Federal Circuit previously held that the key to whether a patent is invalid due to ODP is found in the order in which the patents issued.  Only the last patent to issue could be invalid under the double-patenting doctrine.  However, in two decisions issued by the Federal Circuit on December 7, 2018, the Court further narrowed the applicability of this test thus limiting the cases where obviousness-type double patenting can be used to invalidate patents.

In Breckenridge, the Court addressed a “potential double-patenting situation in which the later-filed of two related patents, which share a common specification and effective filing date, expires before … the earlier-filed patent due to an intervening change in law.”  When the first patent was filed, a patent expired 17 years after the date the patent issued.  When the second patent was filed, the law had been changed under the Uruguay Round Agreements Act of 1994 (“URAA”) so a patent was set to expire 20 years after the patent’s earliest filing date.  This change in law caused the second patent to expire before the first patent.  Applying Gilead, the district court determined the second patent could invalidate the first patent under the obviousness-type double patenting doctrine because the second patent expired first.

In Breckenridge, the Federal Circuit reversed distinguishing Gilead.  In Gilead, both patents had been filed after the effective date of the URAA and claimed different priority dates.  In contrast, in Breckenridge, one patent was filed pre-URAA and one was filed post-URAA.  Thus, the Federal Circuit reasoned a change in patent term law should not truncate the term statutorily assigned to the pre-URAA patent, and therefore, the second patent is not a proper double-patenting reference for invalidating the first patent.

In the second decision, Novartis AG v. Ezra Ventures LLC (“Ezra”), the Federal Circuit addressed “the interplay between a patent term extension (PTE) granted pursuant to 35 U.S.C. §156 and the obviousness-type double patenting doctrine.”  Section 156 “was passed as part of the Hatch-Waxman Act, ‘establish[ing] a patent term extension for patents relating to certain products subject to regulatory delays that could not be marketed prior to regulatory approval.’”  However, “in no event shall more than one patent be extended … for the same regulatory review period for any product.

Ezra argued that, by extending the term of the ‘229 patent, Novartis effectively extended two patents because the ‘229 patent covers a compound necessary to practice the methods claimed by the ‘565 patent.  Therefore, Ezra argued Novartis violated §156 by effectively using the statute to extend the terms for two patents rather than one.  Further, this patent term extension raised the question as to “whether the ‘229 patent is invalid due to obviousness-type double patenting because the term extension it received causes the ‘229 patent to expire after Novartis’s allegedly patentably indistinct ‘565 patent.”

The Federal Circuit concluded that “a PTE pursuant to §156 is valid so long as the extended patent is otherwise valid without the extension.  Thus, the district court was correct in finding that the ‘565 patent is not a double patenting reference to the ‘229 patent and that the ‘229 patent is valid through the end of its PTE.”

Narrowing the applicability of the ruling in Gilead, these two decisions indicate that patents are not likely to fall prey to obviousness-type double patenting issues when there is a change in law or a statutorily permitted extension rather than gamesmanship on the part of a patent applicant.   However, these decisions do not explicitly address all open questions.  For example, given the difference in statutory wording, it is not certain how courts will treat patent term extensions resulting from delays at the patent office.  Will these extensions be treated the same as the §156 extension at issue in Ezra?  What if a patent’s term is first extended for delays in the patent office and then further extended under §156?  These questions are left for another day.