G 1/24 – A New Era of Claim Interpretation at the EPO?

Following on from the Oral Proceedings in March, the EPO’s Enlarged Board of Appeal has now issued its extremely concise decision in the case G 1/24, concluding that the description and drawings shall “always” be consulted to interpret the claims when the EPO is assessing the patentability of an invention, and not only if the claims are found to be unclear in isolation.

Although decisions from the Enlarged Board are always of high importance, this particular decision is arguably one of the most significant in recent years. Claim interpretation is a fundamental aspect of how patents are examined and enforced, and it is therefore no surprise that the decision in G 1/24 has been eagerly awaited in Europe. 

Background

As set out in Article 69 EPC, the extent of protection conferred by a European patent or a European patent application is determined by the claims. Article 69 EPC goes on to state that the description and drawings shall nevertheless be used to interpret the claims.

On first inspection, it would be reasonable to question why a referral to the Enlarged Board was needed at all, given the explicit instruction in Article 69 EPC to use the description when interpreting the claims. However, Article 69 EPC is part of “Chapter III – Effects of the European patent and European patent application” and therefore arguably only applies to interpretation of the claims for the purposes of infringement (i.e., not during patent prosecution).

A further reference to the relationship between the claims and description may be found in Article 84 EPC, which states that in addition to being clear and concise, the claims should be “supported by the description”. Although this language implies some sort of relationship between the two, the extent of this relationship has long been unclear.

In view of these ambiguities, there has been a divergence in the case law of the Boards of Appeal when it comes to claim interpretation at the EPO. In some cases, the Boards have always used the description to interpret the claims, whereas in others, the Boards have only seen fit to refer to the description when the claims are found to be unclear – for example, to determine the definition of an unclear term or phrase.

These issues came to a head in the referring case, T 439/22 – an appeal by Yunnan Tobacco International against the Opposition Division’s decision to reject their Opposition to Philip Morris’ patent EP3076804.

In the referring decision, the Board of Appeal found that the novelty of the claims depended on how the term “gathered sheet” was interpreted. If the term were given its usual meaning in the art, the claims would arguably be novel. However, the description provided an alternative definition for this term which, if used when interpreting the claims, would arguably result in a lack of novelty. Since the term “gathered sheet” was not by itself alleged to be unclear, the issue of novelty, therefore, arguably turned on whether the description should always be used to interpret the claims or not.

To resolve this impasse, the Board of Appeal in T 439/22 referred three questions to the Enlarged Board:

1. Is Article 69(1), second sentence EPC and Article 1 of the Protocol on the Interpretation of Article 69 EPC to be applied on the interpretation of patent claims when assessing the patentability of an invention under Articles 52 to 57 EPC?
2. May the description and figures be consulted when interpreting the claims to assess patentability and, if so, may this be done generally or only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation?
3. May a definition or similar information on a term used in the claims which is explicitly given in the description be disregarded when interpreting the claims to assess patentability and, if so, under what conditions?

The Decision

The Enlarged Board considered Questions 1 and 2 to be admissible, in particular due to the divergence in case law, and due to them both concerning a point of law of fundamental importance. Question 3 was found to be encompassed by Question 2, and was therefore deemed to be inadmissible.

In a departure from typical decisions of the Enlarged Board, the discussion of Questions 1 and 2 was refreshingly brief. The Enlarged Board began by accepting that there was indeed a divergence in case law based on Articles 69 and 84 EPC, before then concluding that neither Article provides an entirely satisfactory basis for claim interpretation when assessing patentability, and that the strictly formal answer to Question 1 would be “No”.

However, the Enlarged Board then went on to note that, despite the lack of explicit basis in the EPC, this has not stopped some previous Boards of Appeal from extracting two general principles of claim interpretation which may be applied more broadly:

1. The claims are the starting point and the basis for assessing the patentability of an invention under Articles 52 to 57 EPC.
2. The description and any drawings are always referred to when interpreting the claims, and not just in the case of unclarity or ambiguity.

The Enlarged Board agreed with these principles, and therefore rejected the diverging case law of Boards which saw no need to refer to the descriptions or drawings when interpreting claims, unless the claims were unclear.

To justify its decision, the Enlarged Board noted that said diverging case law was contrary to the practice of the national courts of the EPC states, and to the practice of the Unified Patent Court (UPC). Or, to put it in the words of the Enlarged Board, it is “a most unattractive proposition that the EPO deliberately adopt a contrary practice to that of the tribunals that are downstream of its patents”.

That the UPC is adopting such an approach appears evidenced by the decision of the UPC Court of Appeal in NanoString Technologies vs. 10x Genomics (UPC_CoA_335/2023), as well as the recent decision of the Paris Local Division in DexCom vs. Abbott (UPC_CFI_230/2023). In the latter decision, the Court found that “the description and the drawings must always be used as explanatory aids for the interpretation of the patent claim and not only to resolve any ambiguities in the patent claim”.

Before wrapping up, the Enlarged Board briefly discussed the effect of their decision on the assessment of a claim’s clarity. Whilst it could be tempting to argue that, going forwards, clarity issues in claims could be resolved by referring to the description, the Enlarged Board instead headed off such an approach by explicitly stating in the decision that “The correct response to any unclarity in a claim is amendment”.

Conclusions

With the decision of the Enlarged Board now in effect, we look forward to seeing how the European patent community responds. The EPO is already well-known for its strict requirements involving amendment of the description prior to grant, and it therefore seems likely that this decision will serve to reinforce the EPO’s approach here. As such, now that the description will apparently “always” be consulted when interpreting the claims, the importance of carefully considering whether amendments to the description may change the meaning of a claim, or whether such amendments add subject-matter, will only increase.

In addition, although the referring decision turned on the use by an Opponent of the description to argue for a broader interpretation of the claims, it appears inevitable that parties will rely on G 1/24 to argue for narrower interpretations of their claims based on the description when it is advantageous to do so.