The referring Board of Appeal in T 1286/23 disagreed with the decision in G 3/04, arguing that it is based on a contradiction in the European Patent Convention (EPC) and that the continuation of appeal proceedings by the intervener finds justification in a legal interest extraneous to European Patent Office (EPO) proceedings. In contrast, the Enlarged Board of Appeal in G 2/24 held that intervention is an exceptional legal remedy, the right to which under the EPC has to fit into the legal and procedural framework of the EPC and Boards of Appeal. That framework affords an intervener entering proceedings at the appeal stage the status only as a party as of right under Article 107, second sentence, EPC.

Decision in G 3/04

As a reminder, in G 3/04 the Enlarged Board of Appeal found that the aim of an intervening third party entering appeal proceedings is to challenge the patent and that the intervening third party thus enters appeal proceedings as an opponent that has not filed an appeal. G 3/04 determined that such a party cannot continue appeal proceedings in the absence of an appealing party, and that this agrees with the principle of party disposition under which proceedings are to be terminated if the procedural steps which gave rise to them are withdrawn.

Events leading to situation in T 1286/23

The intervening third party, Geske GmbH & Co KG, had twice unsuccessfully attempted to intervene during opposition proceedings. Most unfortunate for Geske, the inadmissibility of the second intervention was owed to a delay by the Düsseldorf District Court in serving Geske’s suit to the patent proprietor, Foreo Limited. This prompted the Board of Appeal to comment that had Geske instead “raised the suit before an administrative court and at the same time requested referral to the competent civil court, the suit would have been considered pending at the time it was raised” (1.2.4 of the Reasons). When Geske eventually filed its admissible third intervention, appeal proceedings were pending.

Reasoning of the Board of Appeal in T 1286/23

In its referral, the Board of Appeal argued that the decision in G 3/04 is based on a contradiction in Articles 105 EPC and 107 EPC (3.5.4 of the Reasons). According to the Board of Appeal, the case law interpreting the scope of Article 105 EPC envisages that a third party can intervene at the appeal stage (see G 1/94), while Article 107 EPC does not foresee a role for an intervener entering appeal proceedings.

The Board of Appeal viewed the decision in G 3/04 as accepting that Article 105 EPC overrides Article 107 EPC in so far that the intervener can acquire a status in appeal proceedings despite not having been party to first instance proceedings. Yet according to the Board of Appeal, under the decision in G 3/04 Article 105 EPC does not override Article 107, first sentence, EPC, baring the intervener from becoming an appellant. G 3/04 thus arrives at the status of “non-appealing opponent” for the intervener (3.7.7 and 3.8.5 of the Reasons; 10 of the decision in G 3/04). The Board of Appeal in T 1286/23 disagreed with this conclusion, arguing that the requirements under Article 107 EPC are “replaced by a legal interest extraneous to the proceedings conducted before the European Patent Office”. Finally, the Board of Appeal reasoned that appellant status for an appeal stage intervener is not in conflict with the principle of party disposition, since party disposition does not automatically afford an individual appellant the right to terminate proceedings through their withdrawal (3.13.4 to 3.13.6 of the Reasons).

Basis for reasoning in T 1286/23

The Board of Appeal based its arguments on the reasoning that, contrary to the view in G 3/04, the intervener’s aim is not to challenge the patent in the sense of an opposition, since an opposition may be filed “just in case” (3.4.2 of the Reasons). Rather, the justification for an intervention is derived from a legal interest extraneous to the EPO proceedings, namely being sued for infringement or only threatened therewith. In the eyes of the Board of Appeal, this justification should extend to appeal proceedings. The Board of Appeal considered that it was the patentee’s own choices that lead to another party becoming an intervening third party and so “[h]ere, just as elsewhere in life, one has to face the music one has orchestrated” (3.4.4 of the Reasons).

Admissibility of the referral

Readers may wonder why the Enlarged Board of Appeal admitted the referral in T 1286/23 Enlarged Board of Appeal at all, given that the referred question had already been answered in G 3/04. Indeed, the Enlarged Board of Appeal noted that it does not find the prospect of such a type of referral “particularly appealing in terms of safeguarding consistent case law”. Nevertheless, it admitted the referral in light of the Board of Appeal’s criticism of the legal reasoning in G 3/04 and the referral’s support by the President of the EPO as well as four amicus curiae briefs.

Reasons for the decision in G 2/24

The Enlarged Board of Appeal in G 2/24 first assessed whether there had been any substantive changes in the legal framework since G 3/04. Having found none, the Enlarged Board of Appeal then turned to considering the legal concept of appeals.

The Enlarged Board of Appeal clarified that the purpose of the appeal procedure was that of a judicial review of the decision under appeal, with a view of eliminating any adverse effect that any party of the first instance proceedings may have suffered as a result of a decision deviating from a request made by said party (28 to 34 and 40 of the decision). According to the Enlarged Board of Appeal, only a party adversely affected in such a way can appeal.

In contrast, by virtue of Article 105(2) EPC an intervening third party enters in proceedings as an opponent at the stage the proceedings are at on the date of intervention, making them an accessory party. Given this exceptional nature of intervention (which already supersedes the 9-month rule under Article 99 EPC), the Enlarged Board of Appeal found that its use as a legal remedy under Article 105 EPC could not be applied extensively.

The Enlarged Board of Appeal then considered what this meant in the context of the appeal procedure. Citing from point 7 of the Reasons in G 1/94 that “ambiguity remains as to the interpretation of Article 105 EPC in respect of intervention in appeal proceedings”, the Enlarged Board of Appeal determined that intervention at the appeal stage has to fit into the legal and procedural framework of the Boards of Appeal. This framework is governed, inter alia, by the principles of party disposition, ne ultra petita and reformatio in peius. According to the Enlarged Board of Appeal, the intervener is, in the absence of specific legal provisions to the contrary, bound by these principles and thus becomes a party as of right under Article 107, second sentence, EPC (60 to 66 of the decision). This is in contrast to the Board of Appeal’s view in T 1286/23 that the legal interest extraneous to EPO proceedings on which the intervention is based should take precedence over the requirements of Article 107 EPC.

Finally, the Enlarged Board of Appeal reviewed the legal basis for intervention in several EPC contracting states and the UPC “to ensure harmonised application of the EPC”. From this review the Enlarged Board of Appeal concluded that, where not governed otherwise by way of specific statutory provisions, “an intervention is considered an accessory to the proceedings and ceases to have effect if the proceedings are terminated by the main parties” (97 of the decision). In view of such national jurisprudence, the Enlarged Board of Appeal concluded that the decision in G 3/04 is still in line with the legal framework of appeals and that an explicit legal provision in the EPC would be required to award an intervener an independent party status, that is, a status other than that of a party as of right (102 of the decision).

Final thoughts

The decision reflects the careful balancing act performed by the procedural and legal framework of the EPC and Boards of Appeal, which weighs up third parties’ interests to have a patent’s validity examined centrally against the need for legal certainty. In the present decision, the Enlarged Board of Appeal decided that granting an intervening third party entering appeal proceedings anything other than the status of a party as of right could not be reconciled with this framework.