The impact of an obviousness-type double patenting rejection can be devastating to a patent applicant, since addressing the rejection often involves filing a terminal disclaimer, which truncates the term of the patent in which the rejection was issued. This loss of patent term is particularly detrimental in industries such as pharmaceuticals and biotechnology, where enormous resources are required to develop a drug and bring it to market. Given the gravity of the potential financial impact of an obviousness-type double patenting (OTDP) rejection, one would expect OTDP rejections to be issued in a predictable, reliable, and equitable manner. They are not. Instead, OTDP rejections are often misapplied, inconsistently applied, or applied in a manner that runs afoul of the rationale underlying the doctrine of OTDP.

OTDP rejections are based on a judicially-created doctrine grounded in public policy intended to prevent an unjustified or improper timewise extension of the exclusivity granted by a patent. OTDP applies when the claims in a second patent are from claims in a first patent; that is, when the claims in the second patent are anticipated by or are an obvious variation of the claims of the first patent.

One of the core purposes of the OTDP doctrine is that it protects the ability of the public to access an invention upon expiration of the patent exclusivity period. OTDP thus prohibits a patentee from extending its right to exclude through a second, later-expiring patent that claims an obvious variant of an invention claimed in a first patent. Notably, OTDP is a rejection premised upon prior art. Instead, the focus of the OTDP inquiry is the metes and bounds of the invention that was previously patented; , the invention in the first patent. Despite this, Patent Examiners often assert OTDP arguments that improperly treat a reference patent as prior art. This is commonly observed when the Patent Examiner looks to the specification of a reference patent, rather than to the claims, to demonstrate that the invention claimed in an application is an obvious variant of an invention of the reference patent.

Courts have provided guidance on the mechanics of assessing OTDP. First, an Examiner should construe the claims in the reference patent and the claims of the application at issue and determine the differences between the claims. Second, the Examiner should determine whether those differences render the claims patentably distinct. These guidelines make clear that the doctrine of OTDP applies to inventions that have been patented; that is, inventions that are in an earlier patent. Indeed, the predecessor court to the Federal Circuit confirmed that, for the purposes of OTDP, the disclosure of the reference patent may not be used as prior art.

There are, however, limited permissible uses of the application specification in formulating an OTDP rejection. For example, an Examiner may search a specification to determine the utility of a claimed invention. It is also permissible to look to the specification to resolve ambiguity or indefiniteness in the claims in order to properly construe the claims and understand their scope. Patent applicants facing OTDP rejections should be aware of the proper OTDP assessment and question whether the Examiner has made an improper use of the reference patent's specification.

Another inconsistency in the administration of OTDP rejections lies in the application of the 35 U.S.C. § 121 safe harbor. Under the safe harbor, applications filed as a result of a Restriction Requirement may not be used in a double patenting rejection against the case in which the Restriction Requirement was issued. The upshot is that when an Examiner has identified multiple patentably distinct inventions in an application and issues a restriction requirement resulting in a divisional application, the examiner may not later reject the claims of the divisional application as being patentably from those pursued in the parent application. Though this seems like a straightforward enough premise, the concept is applied to an incongruously narrow set of application filing patterns, leading to unfair and inequitable results.

The Federal Circuit has agreed that the safe harbor applies to a second divisional application filed off of a first divisional application that was filed as a result of a restriction requirement, so long as the second divisional application is directed to subject matter that was divided out of the original application. Similarly, the safe harbor applies to a application filed off of a divisional application, again, so long as the continuation application is directed to subject matter divided out of the original application. In each of the preceding scenarios, the Federal Circuit considered the invention that was claimed in the continuing application in order to determine whether the claims maintained consonance with the restriction requirement of the original case. However, the Federal Circuit departed from this consonance analysis and instead strictly construed the statute in There, the Federal Circuit refused to apply the safe harbor in analyzing a chain of continuation applications even when the continuation applications were directed to divided subject matter. Similarly, the PTAB reached a problematic conclusion in , when the Board determined that a divisional application is not entitled to the benefit of the 35 U.S.C. § 121 safe harbor when a continuation application intervenes in the priority chain.

The purpose of including the safe harbor in the statute was to protect a patentee forced to divide an application by restriction requirement from later facing invalidity due to double patenting. Yet, that is precisely the end result seen in and By wholly disregarding substance of the claims in the continuing application, the USPTO and the courts have become far too strict in their application of the safe harbor.

Finally, another inconsistency relating to OTDP lies in the fact that only certain sources of administrative delay can extend the term of a terminally disclaimed patent. Patent Term Adjustment (PTA) relates to delays in the patent examination process, while Patent Term Extension (PTE) relates to delays in the Food and Drug Administration approval process. Despite these similarities, these two types of term extensions are treated differently with respect to terminal disclaimers.

The statute governing PTA specifically addresses how PTA interacts with terminal disclaimers, providing that “no patent the term of which has been disclaimed beyond a specified date may be adjusted under this section beyond the expiration date specified in the disclaimer.” Accordingly, any length of USPTO delay in processing a patent application becomes irrelevant for patents in which a terminal disclaimer was filed. The statute governing PTE is silent on the interaction of PTE with a terminal disclaimer, but the question has been taken up by district courts and the Federal Circuit. Courts agree that that PTE may be granted to terminally disclaimed patents, effectively extending the term of such patents beyond the expiration date resulting from the terminal disclaimer.

The purpose of both PTA and PTE is to compensate a patentee for the loss of patent term that results from administrative delays. Because both PTE and PTA accrue to a patent via administrative delay beyond the patentee's control, the laws governing PTA and PTE should be harmonized, such that additional patent term is shielded from truncation by terminal disclaimers.

The inconsistencies outlined here are unfair to patentees who rely upon patent protection of their invention to recoup their investment in research and development. It is time for the judiciary to clarify the doctrine that it has created, or for Congress to intervene and amend the statutes that govern the safe harbor and patent term adjustment. With better guidance from the judiciary and Congress, the Examiner Corps will be able to be more consistent with the administration of OTDP rejections.