Integral to the careful balance Congress struck when passing the Hatch-Waxman Amendments, the patent term extension (PTE) is intended to restore patent life that was consumed during regulatory review of an FDA-regulated product. Even though the PTE provisions established in the Drug Price Competition and Patent Restoration Act are forty-plus years old, courts are still grappling with questions about how to best implement the Patent Term Extension. And just last week, a new question was answered by the Federal Circuit: how is a patent term extension calculated for a reissued patent? Is it based on the issue date of the original patent or the reissued patent?
On March 13, 2025, the Federal Circuit ventured into the world of reissued patents and PTE. (FDA has already been there, of course, with respect to 180-day exclusivity.) In Merck Sharp & Dohme Corp. v. Aurobindo Pharma, Ltd. et al., the Court looked at the term “the patent” in the PTE statute at 35 U.S.C. § 156(c) to assess whether the regulatory review period should be calculated using the issuance date of the original patent or the reissued patent. The question is important because the result of that determination could drastically reduce the amount of patent term to be restored.
Questions of the applicability of the PTE statute to reissued patents arose because Plaintiff-Appellee Merck sought extension of a patent listed in the Orange Book after approval of its BRIDION (sugammadex), indicated to reverse neuromuscular blockade, that initially was issued in December 2003 but reissued in January 2014 with the original claims and twelve new claims relating to the drug product. Merck applied for a patent term extension on the reissued patent, claiming the start of the regulatory review period as April 2004 and termination at the approval of the BRIDION NDA in December 2015. With this long regulatory review period, the PTO granted the statutory-maximum five-year patent term extension. This PTE calculation was based on the original patent, but generic filers challenged that decision, arguing that the issuance date of the reissued patent is the operative date for calculating the regulatory review period. In the generic filers’ view, the regulatory review period should have started in January 2014 when the patent was reissued rather than in April 2004, when the IND was opened, because the reissued patent did not exist in April 2004. The plain text of 35 U.S.C. § 156(c), the generic filers contended, required the PTO to calculate the regulatory review period based on the issue date of “the patent” for which PTE was sought, which, in this case, was the reissued patent. The District Court disagreed with generic filers, finding that 35 U.S.C. § 156 should be read in light of the rest of the statute, and that “the patent” in subsection 156(c) must refer to the original patent rather than the reissued patent.
The Federal Circuit upheld the District Court’s position, noting that the language of 35 U.S.C. § 156 “standing alone is ambiguous” and “unclear whether ‘the patent’ refers to the original or reissued patent.” So the Federal Circuit looked at the “the specific context in which that language is used, and the broader context of the statute as a whole.” Specifically, the Court focused on the purpose: “to compensate pharmaceutical companies for the effective truncation of their patent terms while waiting for regulatory approval of new drug applications.” The Court thus explained that interpreting “the patent” in 35 U.S.C. § 156(c) is the best reading, as it “compensates Merck for the period of exclusivity lost due to regulatory delay.” The Court continued: “[t]here is no reason why the Hatch-Waxman Act’s purpose would be served by disabling extensions of the unexpired term solely based on a patent holder’s decision to seek reissue, and Aurobindo offers none.” Thus, “[t]he only construction that comports with the purpose of the Hatch-Waxman Act is one that extends PTE to patent owners who were actually disabled from benefiting from patent protection during the pendency of regulatory review.” Accordingly, in the context of reissued patents, “the patent” in subsection 156(c) refers to the original patent based on the purpose and context of the PTE provisions.
