Claim interpretation UPC vs EPO

Claim interpretation is often decisive for the outcome of patent disputes both regarding validity and infringement.

On 26 February 2024, the Court of Appeal of the UPC issued its NanoString decision (UPC_CoA_335/2023) and ruled that the description always has to be consulted when interpreting the claims and that this interpretation shall be the same both for infringement and validity while the primacy of the claims shall be respected. According to the appeal court, the patent claim is not only the starting point, but the decisive basis for determining the protective scope of a European patent under Art. 69 EPC in conjunction with the Protocol on the Interpretation of Art. 69 EPC.

It now remains to be seen whether the EPO will follow the approach taken by the UPC when assessing validity of EP patents. At present, the EPO seems to be entangled in diverging case law of the Boards of Appeal as will be outlined in the following.

The basic question to be answered is to which extent the description of a patent can or has to be consulted when interpreting the claims. The EPO is entrusted with the grant of EP patents and is in charge for any (necessary?) adaption of the description before grant (in particular to harmonize the claims and description). The impact of these amendments to the description on claim interpretation in infringement and invalidation proceedings, however, depends on the relevance of the description for interpreting the claims.

At present, there is also diverging EPO case law as to which extent the description has to be adapted based on Article 84 EPC and whether Article 84 EPC (which does not apply after grant), can serve as a basis for claim interpretation after grant at all. The question whether the applicant is obliged to perform such amendments to avoid rejection of the application may finally end up in a referral to the Enlarged Board of Appeal (T?56/21).

According to T?169/20, Article 84 EPC provides a legal basis for determining how and when the description has to be consulted. Article 84 EPC stipulates that the claims shall be supported by the description. The Boards stated “the wording of this provision explicitly limits the role of the description to an aid for understanding the subject-matter to be assessed under patentability, while implicitly confining this role to the exceptional cases where such support is both necessary and possible. …”.

According to T?1473/19, the basis for claim interpretation is set by Article 69 EPC and the Protocol for its interpretation, while giving primacy to the claims. On the contrary, Article 84 EPC cannot be used as a basis.

Other decisions take the position that only ambiguous features of the claims should be interpreted by taking the description and drawings into account (T?197/10, T?1514/14).

There are even decisions which state that the description should not even be automatically used for ambiguous features (T?1127/16; see also T?1924/20 and T?2764/19).

It now remains to be seen how the UPC will further develop its case law and whether the EPO will align its diverging approaches accordingly, maybe by making a referral to the Enlarged Board of Appeal to harmonize its case law.

Should you have any questions or like to discuss the above in more detail, please let me know.

Thomas [email protected]