In Re Cellect: Federal Circuit Opens New Path For Double Patenting Challenges

On August 28, 2023, the U.S. Court of Appeals for the Federal Circuit issued a precedential decision in In re Cellect (No. 22-1293) that answered a longstanding question regarding the relationship between Obvious-Type Double Patenting ("ODP") and Patent Term Adjustment ("PTA").¹ Specifically, the Court held that when members of a patent family differ in their expiration dates solely on the basis of PTA, the earlier-expiring family members can be used as the basis for an ODP validity attack on later-expiring family members. This result with respect to ODP in the context of patents with PTA is notably distinct from the Court's holding with respect to ODP in the context of Patent Term Extension ("PTE").² In its 2018 decision in Novartis AG v. Ezra Ventures LLC ("Ezra")³ the Court prohibited this same type of intra-family ODP attack when the difference in expiration dates was due to PTE, rather than PTA. The Court's holding in Cellect is potentially wide-ranging and