Decision G 4/19 of the Enlarged Board of Appeal on the Prohibition of Double Patenting
30 June 2021
The Enlarged Board of Appeal of the European Patent Office recently issued decision G 4/19, which addresses the application of the EPC with regards to double patenting.
“Double patenting” generally refers to the grant of multiple patents to the same applicant, for the same invention, in the same territories. The issue of double patenting may arise in cases where claimed subject-matter is the same for a granted European patent and a European application having the same effective date. For example, this might come about if two applications are filed on the same date (parallel filings), in the case of a divisional and its parent, or in the case of a priority filing and a corresponding priority claiming application (internal priority).
The Enlarged Board of Appeal held that a European patent application can be refused on the grounds that double patenting is prohibited by the EPC.
Background
Whether or not double patenting is allowable is a question of fundamental importance. However, the lack of explicit legal basis in the EPC either for or against double patenting, arguably contradicting case law, and a lack of unanimous agreement between the Contracting States has made interpreting how the EPC applies to double patenting an important legal question.
In the case that led to this referral (European patent application 10718590.2), the pending application had identical claims to a granted European patent from which it claimed priority. The Examination Division decided to refuse the application under Article 97(2) EPC in conjunction with Article 125 EPC. The applicant appealed this decision, partly on the grounds that Article 125 EPC did not provide proper legal basis for prohibiting double patenting.
Although the claim set of the pending application was identical to the claim set of the granted priority-establishing patent, the applicant argued that the later expiry date of the second potential patent meant that the applicant had a legitimate interest in having the second patent granted (citing T 1423/07).
The decision T 1423/07 dealt with a similar situation where the applicant appealed the decision of the Examination Division to refuse an application because the claims of the application were identical to a patent from which it claimed priority. The Board of Appeal in T 1423/07 acknowledged that an applicant could have a legitimate interest in obtaining grant of a second patent where double patenting resulted from a claim to priority, and found that Article 125 EPC did not provide legal basis for the prohibition. The concept of “legitimate interest” was also relevant in earlier cases G 1/05 and G 1/06, where double patenting was discussed in relation to a divisional application and its parent. In obiter dictum statements, the Enlarged Board of Appeal stated 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.
Questions referred
In this case, the Board of Appeal also doubted the applicability of Article 125 EPC as legal basis and referred the following questions to the Enlarged Board of Appeal:
1. Can a European patent application be refused under Article 97(2) EPC if it claims the same subject-matter as a European patent which was granted to the same applicant and does not form part of the state of the art pursuant to Article 54(2) and (3) EPC?
2.1 If the answer to the first question is yes, what are the conditions for such a refusal, and are different conditions to be applied depending on whether the European patent application under examination was filed
a) on the same date as, or
b) as a European divisional application (Article 76(1) EPC) in respect of, or
c) claiming the priority (Article 88 EPC) in respect of a European patent application on the basis of which a European patent was granted to the same applicant?
2.2 In particular, in the last of these cases, does an applicant have a legitimate interest in the grant of a patent on the (subsequent) European patent application in view of the fact that the filing date and not the priority date is the relevant date for calculating the term of the European patent under Article 63(1) EPC?
Decision
The Enlarged Board of Appeal gave the following answers:
1. 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.
2.1. The application can be refused on that legal basis, irrespective of whether it
a) was filed on the same date as, or
b) is an earlier application or a divisional application (Article 76(1) EPC) in respect of, or
c) claims the same priority (Article 88 EPC) as the European patent application leading to the European patent already granted.
2.2. In view of the answer to Question 2.1 a separate answer is not required.
Reasons for the decision
When answering the first question, the Enlarged Board of Appeal determined that Article 125 EPC was the most promising provision with regards to legal basis for the prohibition on double patenting.
Article 125 EPC states that:
“In the absence of procedural provisions in this Convention, the European Patent Office shall take into account the principles of procedural law generally recognised in the Contracting States.”
To assess the suitability of Article 125 EPC as basis the board had to determine whether the issue of double patenting falls under the term “procedural provisions” and whether double patenting is a principle “generally recognised in the Contracting States”.
The applicant had argued that Article 125 EPC did not apply since double patenting was a substantive issue, rather than procedural. However, from examination of the previous case law, the Enlarged Board of Appeal found that the term ‘procedural provision’ may extend to provisions requiring a substantive examination of the subject-matter claimed. According, Article 125 EPC could not be discounted simply because it recited the term ‘procedural provisions’.
Turning to whether double patenting is a principle generally recognised by the Contracting States, the Enlarged Board of Appeal found that the issue of double patenting was sufficiently unclear to justify referring to the preparatory documents of the EPC. The minutes of the various discussions planning the EPC recorded that the prohibition of double patenting had been discussed within the context of Article 125 EPC. However, there was no unanimous agreement between the Contracting States regarding double patenting. In particular, Norway could not agree to the principle of the prohibition since under Scandinavian law it was possible in theory to grant two patents to an applicant for the same invention. Nonetheless, the Enlarged Board concluded that it was clear from the minutes that there was a majority agreement that the prohibition on double patenting was a generally recognised principle of procedural law in the Contracting States, and as such applicable under Article 125 EPC.
In considering question 2.1, the Board found that there was no reason to conclude from the preparatory documents that the prohibition should be applied differently in the different scenarios where double patenting might occur.
Of particular relevance to question 2.2, the minutes recorded that there was a majority agreement that the prohibition of double patenting applied in respect of “applications with the same date of filing.” The applicant argued that this wording meant that the prohibition did not apply to priority claiming applications. However, the Enlarged Boards held that the intent was that the wording of “same date of filing” is to be understood as “same effective date”’ - and so priority claiming applications were not excepted from the prohibition.
Implications for previous decisions
Decision G 4/19 is in line with decisions G 1/05 and G 1/06. However, it is important to note that the Enlarged Board clarified that the statement made in G 1/05 and G 1/06 regarding the prohibition existing on the basis of the applicant having a lack of legitimate interest must be considered in context and did not provide basis to unreservedly approve the prohibition on double patenting.
G4/19 contradicts the opinion of the Board of Appeal in T 1423/07, where the Board found that Article 125 EPC did not provide proper legal basis for the prohibition. Ultimately, the Board in T 1423/07 decided that double patenting was not an issue in this case since the granted patent and the application claiming priority of that patent had different applicants. Specifically, the priority claiming application had been assigned to a new applicant after its refusal, whereas the rights of the priority-establishing patent still belonged to the original applicant. It will be interesting to see if future applicants will circumvent the prohibition in a similar way.
The referring decision and amicus curiae submissions invited the Enlarged Board of Appeal, when answering questions 2.1, to consider the meaning of “the same invention” and “the same applicant”. However, the Enlarged Board of Appeal declined to consider those issues.
Practical Considerations
This decision confirms that the same applicant will not obtain grant of a second European patent in the same territories for the same invention under the EPC. This applies in each scenario where double patenting may occur – even if the applicant has a legitimate interest in the grant of said second patent.
Notably, the scope of this decision only covers the applicability of the prohibition during substantive examination proceedings. The decision does not provide for whether the prohibition applies in opposition proceedings. While double patenting is not a ground of opposition, the prohibition on double patenting under Article 125 EPC might be argued to apply to amendments filed during opposition – perhaps an interesting topic to look out for in future decisions!
