How approaches to double patenting in some jurisdictions leaves a gap in protection that can be exploited by third parties.

A fundamental pillar of a first-to-file patent system is that a later applicant must excise from their claims subject matter claimed in a patent with an earlier priority or filing date, even if that earlier application was not published by the date of filing the later application. In this way, the earlier applicant is afforded a benefit for being the first to file. However, there are many variations in the ways this benefit is applied.

Prior claiming vs excision

In some jurisdictions it is only the matter claimed in the earlier filed patent that must be excised, the so-called “prior claiming” approach; while in other jurisdictions, such as Europe, the later applicant must excise all matter disclosed in the earlier filed application, whether claimed or not.

This latter approach, which goes beyond what is necessary to avoid double patenting, can be justified on the basis that the disclosed subject matter has the potential to be claimed in a patent granted on the earlier application, and it allows examination of the later application to proceed before the claims in the earlier application are finalised.

Both of these approaches allow contiguous protection between the first and second applicants, by allowing the later applicant to claim all subject matter disclosed and enabled in their application that does not appear in the claims or disclosure respectively of the earlier patent.

Gap ripe for exploitation by third parties

However, there are other jurisdictions where the later applicant must excise from their claims more subject matter than is disclosed in the earlier application, thereby creating a “gap” between the protection granted to the later applicant, and the protection available to the earlier applicant.

Examples are the United States, where any subject matter lacking inventive step over the disclosure of the earlier (unpublished) application must also be excised, and Japan and Korea, where subject matter which is “substantially identical” to the earlier disclosure must also be excised.

Since each of these jurisdictions has protection against self-collision, this excision of disclosed subject matter is only required if the applicants of the two conflicting applications are different. However, the result is that a later “different” applicant is denied protection for subject matter they have disclosed and enabled in good faith in their now-published application.

This gap is ripe for exploitation by third parties, since, with the possible exception of equivalents to subject matter claimed in the earlier patent, this subject matter is also not protected by the claims of the earlier patent.

Contiguous protection in the US

But what happens when the applicants are the same?

In the US, provided the claims in the earlier granted patent and the later application are not identical in scope, a terminal disclaimer can be offered (requiring the patentee to maintain common ownership of the two patents, and for the terms to expire on the same date) to maintain contiguous protection between the two patents.

Accordingly no gap is created if the applicants are the same.

Japan and Korea rely on excising ‘substantially identical’ subject matter

However, this is not the case for Japan and Korea where the invention claimed in the later application cannot be “substantially identical” to the invention claimed in a patent granted on the earlier application. This provision requires the applicant to excise from the later application not just subject matter which is identical to subject matter claimed in the earlier filed patent, but also subject matter which is “substantially” identical, thereby creating a gap in the protection obtained by the applicant.

Interestingly, the legal provisions in Japan and Korea that give rise to these gaps use the term “identical” to describe the subject matter to be excised. Unfortunately, the JPO and Japanese courts have interpreted the word “identical” in these provisions to mean “substantially identical”. Had this not occurred, the Japanese and Korean provisions would result in contiguous protection between the two patents, leaving no gap, as is achieved in Europe under the “whole of contents novelty” approach to double patenting.

There is another area where Japanese and Korean law creates an unfortunate gap in protection, and that is where an applicant has filed two applications on the same day or where one application is a parent application and the other is a divisional.

In such cases the claims of the two applications cannot be substantially identical. This means that the claims of a divisional will need to exclude subject matter which is “substantially identical” to the claims granted in the parent.

No protection against self-collision applies to these provisions. Double patenting objections can even be raised where there is no overlap whatsoever between the claims of a divisional and the claims of the parent. An example of such a case is where the parent claims a pharmaceutical compound as a free acid or free base (i.e. not in the form of a salt) and where the divisional seeks to claim the compound in the form of a salt.

Further information

WIPO’s Group B+ has set up a sub-group to study several areas of substantive patent law harmonisation, including in relation to conflicting applications.

FICPI’s position paper on Patent Law Harmonisation, which advocates adoption of the European no gap “whole of contents novelty” approach can be found at here. This paper and its proposals are currently being considered by the B+ sub group.

Next steps

How FICPI makes IP attorneys more effective

FICPI has passed two resolutions on double patenting; one in 2014 dealing with the same applicant and same filing/priority date; and another in 2018 dealing with different filing dates.

In both cases FICPI advocates for an approach that avoids unnecessarily creating a gap in protection that can be exploited by third parties.

FICPI has also drawn the attention of various patent offices to these resolutions, including the JPO and KIPO, cautioning them to “mind the gap”. This was also raised during FICPI’s November ‘Asian tour’, a regular opportunity for FICPI to work closely with Offices to drive towards improved legal IP solutions.

Sharing knowledge through FICPI’s blog, events and meetings enables independent IP attorneys to demonstrate professional excellence and latest knowledge to protect and build value in clients’ IP assets.