The Patent Term Extension (PTE) provisions of 35 U.S.C. § 156 compensate pharmaceutical patent owners for time they are not able to enjoy commercial market exclusivity because their products are not yet approved by the U.S. Food and Drug Administration (FDA). The length of a PTE award depends on how much time was spent under FDA review after the patent was issued. But which issue date is used for a reissued patent? In Merck Sharp & Dohme B.V. v. Aurobindo Pharma USA, Inc., the Federal Circuit decided that the earlier issue date of the original patent should be used to calculate PTE. By essentially preserving PTE awarded to original patents, this decision could encourage pharmaceutical companies to pursue reissue, especially if there are any concerns that broad original claims may not comply with the court’s recent Orange Book listing guidance.

The BRIDION® Patent And Regulatory Review Period at Issue

The patent at issue is listed in the Orange Book for Merck’s BRIDION® (sugammadex) product, which is indicated for the reversal of neuromuscular blockade induced by rocuronium bromide and vecuronium bromide in adult and pediatric patients undergoing surgery. The patent was first issued December 30, 2003, as U.S. Patent No. 6,670,340, and then reissued on January 28, 2014, as U.S. Patent No. RE44,733. The reissued patent amended a dependent claim to expressly recite the active ingredient of BRIDION®.

Merck applied for FDA approval of sugammadex on April 13, 2004 (four months after the ’340 patent issued), and it was approved on December 15, 2015. Thereafter, Merck sought, and the USPTO granted, the maximum five years of PTE available under § 156, using the issue date of the original ’340 patent for the PTE calculation. (If the issue date of U.S. Patent No. RE44,733 had been used, the PTE award would have been only 686 days.)

The challenge to the PTE award arose in the context of ANDA litigation brought by several companies seeking FDA approval to sell generic versions of BRIDION®. The district court agreed with the USPTO’s calculation, and on appeal the Federal Circuit did too.

The Federal Circuit Opinion

The Federal Circuit opinion was authored by Judge Dyk and joined by Judges Mayer and Reyna. As framed in the opinion, the issue on appeal was one of statutory construction—the meaning of “the patent” in §156(c):

The term of a patent eligible for extension under subsection (a) 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 …

The Federal Circuit agreed with the USPTO that the language of §156(c) itself was ambiguous in that it is “unclear whether ‘the patent’ refers to the original or reissued patent.” Thus, the Federal Circuit considered “the broader context of the statute as a whole,” stating:

[T]he purpose of [§ 156] is clear: to compensate pharmaceutical companies for the effective truncation of their patent terms while waiting for regulatory approval of new drug applications.

With this purpose in mind, the opinion reasons:

That purpose applies in this case, since construing “the patent” in subsection 156(c) as the original patent compensates Merck for the period of exclusivity lost due to regulatory delay. On the other hand, Aurobindo’s construction denies Merck compensation for all but a small period of the delay. There 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 …

The opinion concludes:

We thus conclude that, in the context of reissued patents, “the patent” in subsection 156(c) refers to the original patent. A reissued patent is entitled to PTE based on the original patent’s issue date where, as here, the original patent included the same claims directed to a drug product subject to FDA review.

Reissue Patents and Orange Book Listings

As discussed in this article, the Federal Circuit decision in Teva v. Amneal may have patent owners taking a second look at their Orange Book-listed patents, to assess whether they “particularly point out and distinctly claim” the specific drug approved by the FDA. For patents that disclose but do not expressly claim the approved active ingredient, seeking a reissue patent could allay Orange Book listability concerns. The PTE decision in Merck indicates that obtaining a reissued patent would not lessen PTE, providing further reason to consider the reissue process as an opportunity to strengthen a patent portfolio.