Merck Sharp & Dohme B.V. v. Aurobindo Pharma USA, Inc

Authored by: Jeremy J. Gustrowsky

In a significant decision for pharmaceutical patent holders, the Federal Circuit has clarified how patent term extensions (PTEs) apply to reissued patents in the case of Merck Sharp & Dohme B.V. v. Aurobindo Pharma USA, Inc. The core issue was whether the extension should be calculated from the date the original patent was issued or from the date the reissued patent was granted—a question with big implications for how long a drug company can keep generics off the market.

Merck owned U.S. Patent No. 6,670,340, which covered the drug ingredient sugammadex, used in the product BRIDION®. After a lengthy FDA review, Merck reissued the patent as U.S. Patent No. RE44,733, keeping the original claims and adding some narrower ones. When Merck applied for a five-year patent term extension, the Patent Office granted it based on the original patent’s issue date. Generic drug makers challenged this, arguing that the extension should be calculated from the reissue date, which would have resulted in a much shorter period of exclusivity.

The Federal Circuit sided with Merck, holding that for reissued patents, the term “the patent” in the relevant statute refers to the original patent, not the reissued one. The court emphasized that the purpose of the Hatch-Waxman Act is to compensate patent owners for time lost during regulatory review, and using the original patent’s date ensures that companies aren’t penalized for seeking a reissue. The court also noted that the reissued patent inherits the unexpired term of the original patent, so it makes sense to calculate any extension from the original issue date.

This decision provides important clarity for the pharmaceutical industry, confirming that reissuing a patent does not reduce the potential length of a patent term extension. Companies can now be confident that the time lost to FDA review will be restored, even if they reissue their patents to add or clarify claims.