Doubling Down Prohibition of Double Patenting Affirmed at the EPO Through the issuing of decision G 4/19, the Enlarged Board of Appeal (Enlarged Board) has established the legal basis for the prohibition of double patenting. But what does this mean for applicants at the European Patent Office (EPO)? Does it indicate a change in practice, or does it just make official the stance that examiners are already taking during examination? And what further developments should we expect and prepare for? The restriction on double patenting, that is the ability for the EPO to refuse a European application if it claims the same subject-matter as a European patent granted to the same applicant and with the same effective date, has long been a contentious issue at the EPO. The concept of double patenting is not explicitly mentioned in the European Patent Convention (EPC), yet many at the EPO have felt that there is no legitimate reason for an applicant to have two patents granted for the same invention. Therefore, the EPO has relied on interpretation of more general provisions of the EPC in order to raise a double patenting objection, with applicants arguing in response that there is no legal basis for doing so. Slowly, a body of case law from the Boards of Appeal has built up in support of the prohibition and examiners have been able to raise objections with more confidence, but there has been some inconsistency in how cases have been decided. G 4/19 has now brought some clarity to this area.
The referral In 2019 the Board of Appeal, in decision T 318/14, referred three questions to the Enlarged Board to seek a definitive answer as to whether a European application could be refused for double patenting and under what circumstances. The
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Enlarged Board accepted the referral as G 4/19. The subject application in T 318/14 claims priority from an earlier European application. The priority application was granted by the EPO and the pending claims for the subject application were completely identical to those granted for the priority application. The examining division therefore refused the application on the grounds of double patenting and the applicant filed the appeal to challenge that decision. However, the Board of Appeal could find no clear legal provision supporting the prohibition of double patenting, so it asked the Enlarged Board whether an application can be refused for double patenting and if so, what the conditions are for such a refusal.
The prohibition has basis in law The Enlarged Board answered the first referred question in the affirmative, confirming that the prohibition of double patenting does find basis in law. In particular, it stated that a European patent application can be refused under Articles 97(2) and 125 EPC if it claims the same subject-matter as a European patent which has been granted to the same applicant and does not form part of the state of the art pursuant to Article 54(2) and (3) EPC.
With the second referred question, the Board of Appeal wanted to clarify the relationship that is required between the granted patent and pending application for the prohibition to apply. This was of particular relevance because the patent and application of the referral did not have the same filing date and so it was argued that there was a legitimate interest in such circumstances in obtaining grant of the pending application despite the duplication of the subject-matter from the granted priority application (i.e. due to the benefit of up to an additional year of protection). However, the Enlarged Board decided that an application can be refused irrespective of whether it: (a) was filed on the same date as; (b) is an earlier application or a divisional application in respect of; or (c) claims the same priority as, the European patent already granted. The third referred question was directed at whether there is a legitimate interest in the grant of both the priority application and the subsequent application for the same subject-matter, due to the difference in the filing date and so term of the patent. However, the Enlarged Board
