Referral to the Enlarged Board of Appeal of the European Patent Office regarding ”toxic priorities”


Over the past years, there has been quite some debate in Europe about so-called toxic priorities. This refers to situations in which the priority claim of a European patent application is found to be invalid, and said patent application thereby lacks novelty in view of its own priority application. The same kind of situation may arise for a divisional application where the novelty may be destroyed by its parent application when the parent application relates to subject matter entitled to priority while the divisional does not, and vice versa.

In particular, the above-mentioned situations may arise when the subject-matter of a priority application is generalized into a genus in a further application. For instance, the priority application may disclose subject-matter A which in the further application is generalized into genus B, wherein said genus B encompasses subject-matter A without specifically reciting A.

In Europe, the Enlarged Board of Appeal decision G 2/98 points out that “the use of a generic term or formula in a claim for which multiple priorities are claimed in accordance with Article 88(2), second sentence, EPC is perfectly acceptable under Article 87(1) and 88(3) EPC, provided that it gives rise to the claiming of a limited number of clearly defined alternative subject-matters.” However, the interpretation of G2/98 has diverged. In some cases (e.g. T 665/00, T 1877/08 and T 1496/11) the interpretation has been narrow holding that the “clearly defined subject-matter” must be separately identified in the claim. In other cases (e.g. T 1222/11 and T 571/10) the interpretation has been broad holding that the “clearly defined subject-matter” does not need to be specified within the claim as long as it can be identified implicitly.

In T 557/13  a patent was revoked during opposition proceedings. The patent was obtained from a divisional application claiming a genus of the disclosure of the priority application. The Opposition Division applied a narrow interpretation of G 2/98 and held that the priority claim of the patent was invalid, while the priority claim of the parent application was valid. As a consequence, the parent application constituted prior art under Article 54(3) EPC against the divisional patent. Therefore, the divisional patent lacked novelty in view of its parent application.

The patent proprietor filed an appeal arguing that a broad interpretation of G 2/98 should be applied, and that the patent thus should be upheld. The opponent argued that the Opposition Division´s narrow interpretation of G 2/98 should remain. Both parties requested referral to the Enlarged Board of Appeal. The Technical Board of Appeal found that the conditions for referral were fulfilled, i.e. that the case concerned a point of law of fundamental importance and the law had not been applied uniformly, and referred the following questions to the Enlarged Board of Appeal for a decision.

1. Where a claim of a European patent application or patent encompasses alternative subject-matters by virtue of one or more generic expressions or otherwise (generic "OR"-claim), may entitlement to partial priority be refused under the EPC for that claim in respect of alternative subject-matter disclosed (in an enabling manner) for the first time, directly, or at least implicitly, and unambiguously, in the priority document?

2. If the answer is yes, subject to certain conditions, is the proviso "provided that it gives rise to the claiming of a limited number of clearly defined alternative subject-matters" in point 6.7 of G 2/98 to be taken as the legal test for assessing entitlement to partial priority for a generic "OR"-claim?

3. If the answer to question 2 is yes, how are the criteria "limited number" and "clearly defined alternative subject- matters" to be interpreted and applied?

4. If the answer to question 2 is no, how is entitlement to partial priority to be assessed for a generic "OR"-claim?

5. If an affirmative answer is given to question 1, may subject-matter disclosed in a parent or divisional application of a European patent application be cited as state of the art under Article 54(3) EPC against subject-matter disclosed in the priority document and encompassed as an alternative in a generic "OR"-claim of the said European patent application or of the patent granted thereon?

 

While waiting for the decision by the Enlarged Board of Appeal it is advisable to take the above issues into account when considering filing strategies and claim drafting. For more information, please feel free to contact any of the patent attorneys at Valea.

// Louise Tottie, Ylva Skoglösa and Annika Unge Reis