Philip Morris Products v Yunnan Tobacco International (EPO, G 1/24, 2025)

Dhenne Avocats · 11 October 2026

Our analysis

Summary

The Enlarged Board of Appeal held that the claims are the starting point and the basis for assessing patentability under Articles 52 to 57 EPC, and that the description and drawings must always be consulted to interpret them, not only where the skilled person finds a claim unclear or ambiguous when read in isolation. It rejected the line of case law reserving recourse to the description to cases of unclarity, aligning EPO practice with that of national courts and the UPC. The decision cuts across all fields and bears directly on novelty and inventive step arguments in opposition.

Facts and procedure

Philip Morris Products S.A. held EP 3 076 804, concerning a heated aerosol generating article containing tobacco-based material. After the Opposition Division rejected the opposition filed by Yunnan Tobacco International Co., Ltd., the opponent appealed. The dispute turned on the novelty of claim 1 and the term “gathered sheet”: on the proprietor’s case, its usual meaning in the art made the claim novel; on the opponent’s, read in the light of the description it had a broader meaning that destroyed novelty. In interlocutory decision T 439/22 of 24 June 2024, Technical Board of Appeal 3.2.01 referred three questions.

The applicable law

Article 69(1) EPC and Article 1 of the Protocol on its interpretation determine the extent of protection; Article 84 EPC requires the claims to define the matter for which protection is sought and to be clear. The Enlarged Board noted that the boards had based claim interpretation either on Article 69 and the Protocol (G 2/88, G 6/88) or on Article 84 (G 2/12) (point 5).

Question

Is claim interpretation for the assessment of patentability based on Article 69 EPC and its Protocol, and may the description and drawings be consulted generally or only in cases of unclarity or ambiguity?

Decision

The third question, encompassed within the second, was inadmissible; the first two were admissible given diverging case law and their fundamental importance (points 1 to 3). On the first, the Board found that neither Article 69 EPC and the Protocol, arguably concerned only with infringement actions before national courts and the UPC (point 7), nor Article 84 EPC, which is formal in nature (point 8), provides a satisfactory basis: there is no clear legal basis and the strictly formal answer would be “No” (point 9).

The Board extracted two principles: the claims are the starting point and the basis for assessing patentability, and the description and drawings are always referred to when interpreting them (point 12). The first is settled (point 13). The second resolves the divergence: the Board rejected the case law consulting the description only in cases of unclarity or ambiguity (point 14), which is contrary to the wording of Article 69 EPC and to the practice of national courts and the UPC (point 15). It found it a most unattractive proposition for the EPO to adopt a practice contrary to that of the courts downstream of its patents, referring to G 5/83 and G 3/08 (point 16), and noted that finding a claim clear is itself an act of interpretation (point 17). Finally, it stressed the importance of a rigorous clarity examination under Article 84 EPC, amendment being the correct response to unclarity (point 20).

Key points for practice

• The description and drawings are always consulted when interpreting the claims to assess patentability (point 18).
• The claims remain the starting point and the basis of the analysis (point 12).
• There is no clear legal basis in the EPC for claim interpretation at the patentability stage, but the principles derived from the case law continue to apply (points 9 and 10).
• Practical point: in opposition and on appeal, build novelty and inventive step arguments on the claims read with the description, and deal with any unclarity by amendment under Article 84 EPC (point 20).

Relevance before the UPC

The Enlarged Board noted that UPC case law, as expressed in the NanoString v 10x Genomics order, appears consistent with its conclusions (point 19); claim reading in opposition thus moves closer to that adopted by the UPC.

Provisions applied

European Patent Convention

Art. 52, 53, 54, 55, 56, 57, 69(1), 84; Protocol on the Interpretation of Article 69 EPC, Art. 1

Case law cited

G 5/83; G 2/88; G 6/88; G 3/08; G 2/12; T 1871/09; T 2684/17; T 1473/19; T 439/22; UPC Court of Appeal, NanoString Technologies v 10x Genomics, UPC_CoA_335/2023, order of 26 February 2024 as rectified on 11 March 2024

Related decisions

• NanoString Technologies v 10x Genomics, UPC Court of Appeal, UPC_CoA_335/2023, 26 February 2024, order cited as consistent with the Enlarged Board’s conclusions.
• Eisai, G 5/83, EPO Enlarged Board of Appeal, 5 December 1984, cited for the harmonisation philosophy of the EPC.

Prepared by Dhenne Avocats from the text of the decision (epo.org, official English text), consulted on 11 October 2026. Only the official text is authoritative.