In its most recent decision addressing the complicated interplay between Patent Term Adjustment (PTA) and obviousness-type double patenting (OTDP), the Federal Circuit ruled that a first-filed, first-issued parent patent awarded PTA cannot be invalidated for OTDP in view of a later-filed, later-issued child patent that expires earlier because it did not earn PTA. This decision in effect permits a first-filed, first-issued parent patent to benefit from its PTA award.

The challenged patent granted from the first nonprovisional patent application filed in the patent family at issue, and was awarded over 1,000 days of PTA. The patents asserted as OTDP reference patents stemmed from child applications filed after the challenged patent was issued. The child patents claim priority to the challenged patent through an intervening child application and did not earn any PTA. Thus, the patent family represents the not-so-unusual circumstance of a patent family wherein only the first patent was awarded PTA, such that it has a later expiration date than its child patents.

The Federal Circuit decision (by the same panel of judges who decided Cellect) includes a review of prior decisions addressing the interplay between PTA and OTDP, leaving the reader with a clear understanding that it’s complicated.

• In Gilead, a later-filed, earlier-issued patent was invalid for OTDP in view of an earlier-filed, later-issued patent with an earlier expiration date stemming from a different priority claim.
• In Cellect, the patents at issue were invalid for OTDP in view of (i) an earlier-filed, earlier-issued patent; (ii) a later-filed, earlier issued patent, and (iii) a later-filed, later-issued patent.

Now in Allergan, the Federal Circuit holds:

A first-filed, first-issued, later-expiring claim cannot be invalidated by a later-filed, later-issued, earlier-expiring reference claim having a common priority date.

In reaching this decision, the opinion states:

The fact that the ’356 patent expires later is of no consequence here because it is not a second, later expiring patent for the same invention. As the first-filed, first-issued patent in its family, it is the patent that sets the maximum period of exclusivity for the claimed subject matter and any patentably indistinct variants.

Lest anyone lose sleep trying to reconcile the underlying facts of the Federal Circuit’s OTDP/PTA jurisprudence, the opinion invokes “the principle of party presentation” and only considers how previous Federal Circuit decisions resolved the specific “question presented” by the parties. Thus, the opinion explains, Cellect “established a rule that, when it comes to evaluating ODP on a patent that has received PTA, the relevant expiration date is the expiration date including PTA — not the original expiration date measured 20 years from the priority date,” but “did not address, let alone resolve…under what circumstances can a claim properly serve as an ODP reference.”

Thus, while Allergan expressly holds that a “first-filed, first-issued, later-expiring claim cannot be invalidated by a later-filed, later-issued, earlier-expiring reference claim having a common priority date,” stakeholders should be cautious in extrapolating that holding to different OTDP/PTA scenarios.