The Federal Circuit has issued a decision that clarifies the interaction between terminal disclaimers, obviousness-type double patenting and patent term adjustment in US patent practice. Obviousness-type double patenting is a US patent doctrine that is directed towards handling patent applications which are “patentably indistinct”. A rejection for obviousness-type double patenting is generally addressed by filing a terminal disclaimer which ensures that the patentably indistinct patents have the same (earliest) expiration date and common ownership.
Obviousness-type double patenting doctrine arises from a period when the expiration of a patent was determined by its date of issuance. The doctrine prevented the improper effective extension of a patent term by filing multiple related applications with overlapping inventive scope. Changes to US patent law have since caused patent terms to be determined by the filing date of the originating application. However, a point of uncertainty has remained about how the relatively new practice of patent term adjustment (PTA) interacts with obviousness-type double patenting and terminal disclaimers. PTA extends the term of patents if delays in prosecution in the patent office exceed a reasonable time period.
The Federal Circuit has issued a decision in IN RE: CELLECT, LLC, in which the appellant had multiple patents arising from a common filing and had not filed terminal disclaimers with respect to the various issued patents. The Federal Circuit concluded that expiry of the earliest patent without terminal disclaimers made any surviving patentably indistinct patents invalid. The appellant Cellect, LLC could not correct this issue because the terminal disclaimer could not be filed after the expiry of the earliest expiring patent.
A consequence of this decision is that holders of families of related patents may risk the invalidation of later-expiring patents (due to PTA) if terminal disclaimers have not been filed prior to the expiry of the first expiring patent.
The full Federal Circuit decision may be found here.