Jennifer Nall, left, and Henry Fildes, right, of DLA Piper. Courtesy photos.

Introduction

The doctrine of obvious-type double patenting (ODP), also known as non-statutory double patenting, recently became a very hot topic for patent owners and practitioners after two notable events. ODP is a judicially created doctrine that prevents an improper timewise extension of the patent term by prohibiting claims in a second patent not patentably distinct from claims in a first patent. The USPTO will reject, under the doctrine of ODP, patentably indistinct claims in certain circumstances. A patent applicant may overcome ODP by filing a terminal disclaimer, which disclaims any patent term longer than the term of an unexpired first patent and requires the ownership of both patents to be co-extensive. A terminal disclaimer ensures that the term of the patent with the terminal disclaimer will not extend beyond the term of the patent forming the basis of the non-statutory double patenting. 

Two recent events have brought ODP to the forefront of patent practitioners' minds. First, the Federal Circuit's In re Cellect decision held that when patent family members differ in expiration dates because of Patent Term Adjustment (PTA), the earlier-expiring family member can be used as the basis for an ODP validity attack on later-expiring family members. Second, the USPTO recently issued a notice of proposed rulemaking (NPRM) on terminal disclaimer practice. Under the USPTO's proposed rule, inter-alia, a terminal disclaimer must include an agreement that the subject patent will be unenforceable if tied to another patent that has any claim invalidated or canceled based on prior art. In re Cellect and the USPTO's proposed rule have the potential to fundamentally affect patent practice, particularly in the realm of terminal disclaimers filed to overcome ODP rejections. 

'In re Cellect'

On Aug. 28, 2023, the U.S. Court of Appeals for the Federal Circuit issued a precedential decision in In re Cellect, holding that when patent family members differ in expiration dates because of PTA, the earlier-expiring family member can be used as the basis for an ODP validity attack on later-expiring family members. In re Cellect arose from the appeal of four related ex parte reexamination proceedings involving a family of patents, many of which received varying amounts of PTA due solely to prosecution delays by the USPTO. Because each family member patent claimed priority from the same application (and none were subject to a terminal disclaimer), each would have expired on the same day but for the individual grants of PTA. As a result, the family had a wide range of different expiration dates.