The judicially created doctrine of obviousness-type double patenting, or ODP, can be a potent defense in litigation. Under the ODP doctrine, patent claims that are not patentably distinct from those in a commonly owned, earlier-filed patent are subject to invalidation.

Grounded on the principle that each invention should be limited to one patent term, the ODP doctrine was created to deter parties from procuring sequential patents with different expiration dates claims to the same invention, or obvious variants of the same invention,1 the primary concern being that a patentee who obtains such patents could:

  • Engage in serial litigation; or
  • Sell the patents to different entities only to have both entities separately sue an alleged infringer for effectively the same thing.2

On its face, the ODP analysis may seem relatively straightforward, but its application has proven to be confounding. In general, when two patents are alleged to claim the same invention, but one has a later expiration date, a court must determine whether differences between the claims render them patentably distinct — whether the later claims are obviously over or anticipated by the earlier claims.

If the claims are not patentably distinct, then the later-expiring patent can be invalidated. In some circumstances, however, a patentee may file a terminal disclaimer to overcome that basis of invalidity.3 The terminal disclaimer statutorily disclaims "any terminal part of the term" of the later-expiring patent so that both patents expire on the same date.4

Doing so may eliminate concerns over gamesmanship by the patentee to extend its patent rights.

Adding complexity, there are some instances in which the expiration dates of related or similar patents have different terms as a result of statutorily provided patent term adjustments or extensions. The question has thus arisen as to how the ODP doctrine should apply when patent terms are extended Rachel Elsby Brooks Kenyon Svetlana Pavlovic through permissible means and by statutory grant. On this question, courts and the Patent Trial and Appeal Board are divided.

Modifications to Patent Terms

A patentee is generally provided 20 years of patent exclusivity from the filing date of the first nonprovisional application from which priority is claimed.5 However, Congress has provided two mechanisms by which that term can be extended.

First, when a patent's issuance is delayed during prosecution, the patent's term can be adjusted under Title 35 of the U.S Code, Section 154(b) to account for those delays. Notably, filing a terminal disclaimer limits the availability of patent term adjustment, or PTA.6

Second, because certain inventions, such as pharmaceutical compositions, are subject to lengthy regulatory review periods prior to commercial marketing that can effectively reduce a patent's term, Congress provided a mechanism to recover patent term lost as a result of that review.

Specifically, when a patent claims an invention related to a product subject to regulatory approval by the U.S. Food and Drug Administration, its term may, under certain circumstances, qualify for a patent term extension, or PTE, under Title 35 of the U.S. Code, Section 156 if there are delays in the approval process at the regulatory agency.

Unlike PTA, PTE grants are not limited by the filing of terminal disclaimers.

Both PTA and PTE extensions are common and can be particularly important to the pharmaceutical and biotechnology industries. It is often the case that parties in these industries will file patent applications early in the research and development process, but not launch products until long after patents issue due to the extensive preclinical research and clinical trials that must be performed before a drug can be sold to the public.

The Impact of PTA and PTE on the ODP Doctrine

In years past, the U.S. Court of Appeals for the Federal Circuit has addressed whether a later-issued, earlier-expiring patent can be used as an ODP reference — It can. In the Gilead Sciences Inc. v. Natco Pharma Ltd. decision, the Federal Circuit held that although the reference patent (the '375 patent below) issued after the challenged patent (the '483 patent below), its earlier expiration dated qualified it as prior art for ODP purposes based on the timeline below.

Originally Published by Law360

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