Holding: PTE for a reissued patent is calculated based on the issue date of the original patent when the reissued patent includes claims for the same drug product that was claimed in the original patent and that was subject to FDA review.
Merck owns US Patent No. 6,670,340, which issued on December 30, 2003, and is directed to a class of 6-merapto-cyclodextrin derivatives. Four months after the ‘340 Patent issued, Merck applied for FDA approval of sugammadex, one of the derivatives claimed in the ‘340 Patent, and a drug that is used to reverse neuromuscular blockade. While the FDA review was pending, Merck filed a reissue application with the USPTO that retained the original claims of the ‘340 Patent and added some narrower claims that were directed specifically to sugammadex. The ‘340 Patent was reissued as US Patent No. RE44,733 on January 28, 2014.
The FDA review process continued until suggamadex was approved on December 15, 2015, twelve years after the issuance of the ‘340 Patent. Merck filed a patent term extension (PTE) application for the RE’733 Patent on February 10, 2016, and applied for the maximum of five years of PTE based on the initial issue date of the ‘340 Patent. The USPTO granted the full five-year extension to the expiration date of the RE’733 Patent based on the start date of the FDA review in 2004 and the date of issuance of the ’340 Patent in 2003. Therefore, the expiration date for the RE’733 Patent was extended from January 27, 2021 to January 27, 2026.
The formula for determining PTE is set forth in 35 U.S.C. §156(c), which states that the “term of a patent eligible for extension . . . shall be extended by the time equal to the regulatory review period for the approved product which period occurs after the date the patent is issued[.]” Section 156 sets a five year maximum for an extension based on the regulatory review period. 35 U.S.C. §156(g)(6).
In early 2020, Aurobindo filed an Abbreviated New Drug Application (ANDA) with the FDA for approval to sell a generic version of Merck’s suggamadex drug, BRIDION®. In response, Merck filed suit for patent infringement. Aurobindo argued that the USPTO erred in granting the RE’733 Patent five years of PTE by calculating the extension based on the original issue date of the ‘340 Patent rather than the issue date of the RE’733 Patent. Calculating PTE from the issue date of the RE’733 Patent would reduce the extension to only 686 days, the amount of time of the FDA review period that occurred after the issuance of the RE’733 Patent.
The Federal Circuit upheld the district court’s decision, finding that for a reissue application, PTE is calculated from the issue date of the original patent rather the issue date of the reissued patent. The Federal Court’s analysis was focused on the statutory construction of Section 156, and in particular, on the meaning of the term “the patent” when determining PTE for a reissued patent. According to the Federal Circuit, the language of Section 156(c) on its own is ambiguous, as it is unclear as to whether “the patent” means the original patent or the reissued patent. Therefore, the broader context of the Hatch-Waxman Act as a whole must be considered.
The purpose of the Section 156 is to compensate patent owners for the portion of their patent term that is lost while waiting for regulatory approval of a new drug application. PTE provides the patent owner with additional patent term to make up for the term that is lost due to FDA delay. A construction of Section 156 that bases PTE on the issue date of the reissued application shortens this compensation based solely on a patent owner’s decision to seek reissue, and does not further the purpose of the statute. Therefore, the term “the patent” in Section 156 should be construed to mean the original patent, and a reissued patent is entitled to PTE based on the issue date of the original patent as long as the original patent included the same claims directed to a drug product subject to FDA review.
Aurobindo argued that PTE must be calculated based on the issue date of the reissued patent, since the original patent is “dead” upon reissue. However, the Federal Circuit stated that although the patent owner no longer has enforceable rights under the original patent, the reissued patent inherits the unexpired part of term of the original patent. Section 156 does not seek to make the original patent enforceable after reissue, it only seeks to extend the term of the original patent. This extended term may be transferred to the reissued patent.
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