The Enlarged Board of Appeal hears case G1/23

The long-anticipated oral proceedings in case G1/23 took place on 12 March 2025. We await the final written decision but it would appear that there may be a significant change to the approach taken by the European Patent Office (EPO) with regard to the information which can be derived from products which have put on the market. Both patent examination and opposition proceedings before the EPO may be impacted.

The background to the case revolves around whether the approach taken by the Enlarged Board of Appeal (EBA) in previous case G1/92 is still appropriate, and if so, to what extent. As the ultimate arbiter of matters of law pertaining to the European Patent Convention, decisions made by the EBA must be followed by all lower divisions of the EPO. Only the EBA has the power to amend or reverse its previous rulings, or to provide guidance on their interpretation.

G1/92 considered whether the chemical composition of a particular product is made available to the public when that product is put on the market. It was ruled that the chemical composition of a publicly available product forms part of the state of the art if the product can be analysed and reproduced by the skilled person.

Following G1/92, many Technical Boards of Appeal have sought to implement the Enlarged Board’s rulings, but as often happens, differing interpretations have developed. The main point of contention is the twin requirement that the relevant product must be able to be analysed and reproduced by the skilled person. Matters came to a head in case T438/19 where the critical issue was whether the composition of a commercially available polymer material forms part of the state of the art. There was no doubt that the product itself could be obtained and so analysed to some extent. It was less clear whether such analysis would then enable the skilled person to reproduce the polymer. The Board of Appeal, seeking guidance on the correct application of G1/92, referred the following questions to the EBA as G1/23:

1. Is a product put on the market before the date of filing of a European patent application to be excluded from the state of the art within the meaning of Article 54(2) EPC for the sole reason that its composition or internal structure could not be analysed and reproduced without undue burden by the skilled person before that date?
2. If the answer to question 1 is no, is technical information about said product which was made available to the public before the filing date (e.g. by publication of technical brochure, non-patent or patent literature) state of the art within the meaning of Article 54(2) EPC, irrespective of whether the composition or internal structure of the product could be analysed and reproduced without undue burden by the skilled person before that date?
3. If the answer to question 1 is yes or the answer to question 2 is no, which criteria are to be applied in order to determine whether or not the composition or internal structure of the product could be analysed and reproduced without undue burden within the meaning of opinion G 1/92? In particular, is it required that the composition and internal structure of the product be fully analysable and identically reproducible?

The EBoA provided their preliminary view last year in advance of the oral proceedings. They expressed concern that the strict requirement that the product be fully analysable and identically reproducible could lead to the absurd situation where a readily available, commercial product could nevertheless not be part of the state of the art. Logically, this could lead to the situation where an ‘old’ product would be considered novel and thus patentable.

The EBoA expressed the opinion that G 1/92 could not have intended such an absurd consequence. They suggested that the skilled person could be expected to take a more realistic approach whereby all analysable features of a product which has been put on the market, including where appropriate, its chemical composition, should be considered to be part of the state of the art.

Reports of the oral proceedings held on 12 March 2025 indicate that the EBA may be minded to follow their original preliminary opinion. The strict requirements of G1/92 that the relevant product be fully analysable and identically reproducible could thus be a thing of the past. For patent applicants, this has the potential to widen the scope of the prior art which may be citable in examination and reinforces the need to make sure that patent applications are filed prior to any product launch. For opponents seeking to invalidate granted patents, G1/23 has the potential to enlarge the pool of possible prior art to include products which although widely available, may be difficult to reverse engineer.

The EBA will publish their full written decision for G1/23 in due course so we will learn in detail how previous practice under G1/92 will change. In the meantime, our attorneys here at Matisen & Macara would be delighted to answer any questions you may have about this important case, or on any other aspects of patent law and practice.