Insights: G1/23 – A burdensome new referral to the EPO’s Enlarged Board regarding the state of the art

Can a product be simultaneously available and unavailable to the public? In T 0438/19 , the Board grappled with questions regarding the criteria that must be met for a product to form part of the state of the art in accordance with Article 54(2) EPC. Pointing to divergent approaches in how the leading decision in this area, G 1/92, has been applied in the case law of the Boards of Appeal, the Board in T 0438/19 concluded that a referral to the EPO’s Enlarged Board is necessary.

The referred questions are as follows:

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?

Legal Background

Article 54(2) of the EPC sets out that the “state of the art shall be held to comprise everything made available to the public by means of a written or oral description, by use, or in any other way, before the date of filing of the European patent application”.

According to decision G1/92, the “chemical composition of a product is state of the art when the product as such is available to the public and can be analysed and reproduced by the skilled person, irrespective of whether or not particular reasons can be identified for analysing the composition” and the “same principle applies mutatis mutandis to any other product”.

In G1/92 the Enlarged Board reasoned that an “essential purpose of any technical teaching is to enable the person skilled in the art to manufacture or use a given product by applying such teaching. Where such teaching results from a product put on the market, the person skilled in the art will have to rely on his general technical knowledge to gather all information enabling him to prepare the said product. Where it is possible for the skilled person to discover the composition or the internal structure of the product and to reproduce it without undue burden, then both the product and its composition or internal structure become state of the art“.

Background to the case

The referral arises from an appeal (T0438/19) filed against the decision of the Opposition Division to reject an opposition filed against EP2626911, which relates to an encapsulating material comprising a copolymer.

In T 0438/19, the parties expressed conflicting views as to what, if anything, had been made available to the public by way of a commercially available product.

It was common ground that the product ENGAGE® 8400, an ethylene-octene copolymer, was commercially available before the effective filing date; and that it fulfilled all of the properties required by claim 1 as granted, with the exception of the content of aluminium. The product was thus in any event not prejudicial to the novelty of the claims. However, the issues regarding its public availability were relevant for the assessment of inventive step under Article 56 EPC.

In addition to the product itself, the Board also had to consider documents (published before the filing date of the patent in suit) that mentioned ENGAGE® 8400 and disclosed some properties thereof, but were silent on how to make the product, and failed to provide full details of the chemical composition/internal structure thereof.

As ENGAGE® 8400 is a copolymer, it exhibits a complex molecular structure. It is widely accepted that there are challenges concerning the determination of the precise chemical composition and internal structure of a copolymer; and that reverse-engineering to arrive at a process to reproduce the copolymer may well require extensive research. In view of their complexity, copolymers are typically defined in terms of various properties and statistical parameters at a macroscopical level which relate to their structure.

Divergent approaches in applying G1/92

In T 0438/19, the Board broke down the requirements set out in G1/92 into three aspects, noting that there is divergent case law in relation to each of these aspects.

Aspect (i) is the interpretation of “available to the public”. If the chemical composition/internal structure of a product cannot be determined without undue burden, should the product be excluded from the state of the art (following e.g., T 23/11)? Or should only its chemical composition/internal structure be excluded from the state of the art (following e.g., T 1666/16)?

Aspect (ii) is the degree of detail required for the analysis of said product. The Board noted that in some decisions the exact composition of the product was required (e.g., T 946/04). By contrast, in other decisions the absence of certainty about the knowledge of some structural elements of a product did not disqualify that product as the closest prior art (e.g., T2458/09).

Aspect (iii) concerns the requirements for the reproducibility of the product. Whereas some Boards have taken as a criterion the ability to exactly reproduce the product (e.g., T 1833/14), in other decisions such a strict criterion has not been applied (e.g., T 1540/21).

Considerations in T 0438/19

In relation to aspect (i), the Board noted that if ENGAGE® 8400 is considered to be available to the public even if its internal structure is not available, then the product could be used as a starting point for the assessment of inventive step, given that technical information about that product reported in documents of the state of the art, including its potential uses and advantages, make it of particular interest for the skilled person.

The Board further noted that in relation to complex polymers, there does not appear to be a generally recognised definition in the art of what would constitute a comprehensive analysis of the product. Accordingly, there is a risk that a determination as to whether the product has been analysed in sufficient detail would involve an element of subjectivity.

The Board concluded that there is a need to refer the questions listed above to the Enlarged Board of Appeal, to ensure uniform application of the law and because points of law of fundamental importance have arisen.

Whilst the referring case concerns a copolymer, the decision of the Enlarged Board of Appeal will no doubt have a wider impact.