Double patenting under the EPC

This article was included in our Summer 2010 edition of Inside IP magazine.

A recent decision by the Technical Board of Appeal of the European Patent Office (EPO) has brought the issue of double patenting under the European Patent Convention (EPC) back into the spotlight.  In T1423/07, issued on 27 April 2010 and not at the time of writing available on the EPO’s website, the Board of Appeal disagreed with the view taken in an earlier decision T307/03, and concluded that there is no basis in European patent law for refusing a European patent application on the grounds of double patenting.

Double patenting is the granting of two patents to the same applicant for the same invention.  The issue of double patenting generally occurs in respect of a divisional application which claims the same subject matter as the parent application, perhaps in broader terms.  However, double patenting may also be an issue when an applicant files a European patent application claiming priority from, and claiming the same invention as, an earlier European patent application, as happened in this case.  The issue of whether two cases relate to the same invention is outside the scope of this article.

The European Patent Convention (EPC) does not contain any specific provisions relating to double patenting, and it was held in T587/98 that there is no express or implicit provision in the EPC which prohibits double patenting.  However, the Guidelines for Examination in the EPO states ‘it is an accepted principle in most patent systems that two patents cannot be granted to the same applicant for one invention’ and requires examiners not to allow patent grant where it would result in double patenting.  The Board in the present case evaluated the principles of law generally recognised in the contracting states of the EPC, and concluded that the majority of contracting states do not allow double patenting in a situation where there is both a national patent and a European patent designating the same contracting state.  Upon further consideration however, the Board concluded that, with the exception of UK, Ireland and Germany, none of the contracting states contain a principle of law which allows the refusal of a national patent application for double patenting at the pre-grant stage.

T1423/07 appears to refute the controversial earlier decision, T307/03, which followed shortly after Enlarged Board of Appeal decisions G1/05 and G1/06 which stated in passing, but not in the part of the decision that is binding on lower Boards, that “the principle of prohibition of double patenting exists on the basis that an applicant has no legitimate interest in proceedings leading to the grant of a second patent for the same subject matter if he already possesses one granted patent therefor”.  It was concluded in T307/03 that there was basis for refusing a patent application for double patenting in Art. 60 EPC.  This article states that ‘The right for a European patent shall belong to the inventor…” and as a result the Board deduced that the inventor “has the right to the grant of one and only one patent from the European Patent Office for a particular invention as defined in a particular claim”.

However, the Board in T1423/07 considered the conclusions of T307/03 and completely disregarded them, and stated that the intentional decision of the drafters of the EPC not to include a prohibition on double patenting is decisive. In view of the above contrasting opin-ions, it is perhaps surprising that the Board of Appeal did not feel it necessary to refer a question to the Enlarged Board of Appeal.  However, in this instance the Board felt that the present case differed from the facts previously considered by the Enlarged Board because the earlier case considered double patenting for divisional applications.  Further, it may be surmised from the Board’s conclusions that, in the present case, the applicant has a legitimate interest in obtaining grant of the second application claiming priority from the first application, because a granted second patent would expire later than a first application due to the term of a patent being calculated from the filing date and not the priority date.  Interestingly, US law includes provision of a terminal disclaimer which limits the term of the second patent to that of the first to restrict such an instance occurring.

It is clear that there are a number of issues that have not been fully resolved, even though the Board of Appeal did not feel it necessary to refer a question to the Enlarged Board in this instance.  There-fore, it is likely that the Examining Division will continue to refuse, albeit on an infrequent basis, patent applications on the basis of double patenting as they will continue to follow the Guidelines, and so it will not be surprising if a future Board of Appeal is faced with a similar case, and subsequently arrives at a different decision, to the present one.

David Paton 14 Jun 2010

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