In August 2023, the Federal Circuit in In re Cellect held that in evaluating unpatentability for obviousness-type double patenting (ODP) of a patent that has received patent term adjustment (PTA), the relevant date is the reference patent’s expiration date after PTA is added. 2 Cellect promptly filed a petition for rehearing en banc. A flood of amicus briefs in support of a rehearing ensued, filed by key players in the pharmaceutical industry including AbbVie, Merck, Novartis, AstraZeneca, and Johnson & Johnson, among others. Although the petition was ultimately denied, this case has ongoing implications. These implications, together with additional cases that may yet be impactful, are summarized here.

Originally published in the Spring 2024 edition of Chemical Practice Chronicles.