EPO decision G1/23 clarifies that irreproducibility does not exclude a marketed product from the state of the art but related evidential issues may still arise
EPO Enlarged Board of Appeal (EBA) decision G1/23 has clarified that a marketed product cannot be ignored as prior art on the basis that reproducibility was not possible by a person skilled in the art at the relevant date. This decision is of particular interest in relation to complex polymers and other complex products where inability of full characterisation prevents manufacture by others beyond the originator. The Appeal Board case T0438/19 leading to the EBA referral resulted from just such consideration of a commercially available copolymer, ENGAGE®8400, for the manufacture of solar cells. In further considering such a copolymer, the EBA sought to clarify rather than overturn earlier EBA Decision G1/92 by distinguishing ‘product’ and ‘composition’ (or ‘internal structure’) and further considering in depth how the reproducibility requirement should be assessed to reflect practical reality and avoid absurd legal fiction. G1/23 sets out the following answers to the referred questions:
- A product put on the market before the date of filing of a European patent application cannot 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 by the skilled person before that date.
- Technical information about such a product which was made available to the public before the filing date forms part of the state of the art within the meaning of Article 54(2) EPC, irrespective of whether the skilled person could analyse and reproduce the product and its composition or internal structure before that date.
In coming to these conclusions, the EBA held that “the expected reproducibility of the product must be understood in a broader sense, namely as the ability of the skilled person to obtain and possess the physical product” (para. 73 of reasons, emphasis added). It follows from consistency with G1/92 that all analysable properties of a product put on the market will also belong to the state of the art with reference to the skilled person and common general knowledge in the relevant field. A distinction is to be made between technical teaching derivable from the physical product and the technical teaching (analysability without undue burden) required for manufacturing the product.
By way of example, the EBA noted that simply adding lemon juice to Coca-Cola to provide a less sweet taste may not be deemed inventive simply because the recipe for Coca-Cola is secret. This picked up a point of the patentees as regards the hypothetical situation of a broad claim merely defining a caramel-coloured fizzy drink which undoubtedly encompasses Coca-Cola against the evident knowledge that Coca-Cola contains water, carbon dioxide and colouring. (para. 96 of reasons).
Returning to the foundation for the referral, it was not disputed that claim 1 of the patent of concern (EP2626911) was directed to an ethylene/α-olefin copolymer defined by reference to various parameters and that ahead of the priority date it was recognisable that ENGAGE®8400 complied with all the relevant parameters except the aluminium content range. Furthermore, ENGAGE®8400 was disclosed in an example of a published WO application suggesting materials for use in solar cells. Following G1/23, the only matter thus remaining to be deliberated is whether inventive step can reside in increasing the aluminium content, given that sufficiency has been upheld.
Potential issues posing evidential burden after G1/23
The above examples illustrate relatively simple situations where there is no dispute over the prior art effect of product marketing. However, G1/23 leaves plenty of potential issues posing evidential burden. Indeed, the EBA has provided much discussion on one of these: What is the situation if a man-made, non-reproducible product was marketed but this is discontinued ahead of the date of note?
The EBA dismissed that such a situation leads to non-compliance with ‘available to the public’ for the purpose of Article 54(2) EPC. They explicitly noted the ‘practical legal problem of proof’ of what exactly became state of the art ahead of the relevant date in such a situation, but saw this as no different from the situation addressed in Appeal Board decision T1553/06 of an internet disclosure being available for only short time; it was still deemed on the basis of evidence as belonging to the state of the art (para. 85 of reasons).
Disappearance of a product ahead of a date for patent validity challenge may be through stopping of commercialisation entirely or developmental change, possibly under the same labelling. In either case, issue may arise in establishing one or more properties of the product. The actual date a product came into prior use may also be a keenly contested issue. It is therefore additionally worthy of note that a line of EPO Appeal Board decisions concerning standard of proof for prior disclosure or prior use (T1138/20, T0832/22, T2463/22, T0733/23) now points to a need for free evaluation of all the evidence and conviction of the deciding body being paramount; there is only one standard of proof.
What should be understood by ‘undue burden’ in establishing a product property was also recognised by the EBA as a source of contention but as not affecting prior art status of the product as such. Rather, the significance may be in founding an insufficiency versus obviousness squeeze attack on claim validity.
Remaining relevance of T0576/91
G1/23 does not detract from the conclusion of Appeal Board Decision T0576/91 that a product such as a DNA construct noted in a scientific journal does not qualify as prior art merely by the fact that the authors may feel bound by an ‘unwritten ethical rule’ to supply samples upon request. Hence where a product is first noted in a scientific journal, further investigation may be required to determine if it had been made truly publicly available, e.g., by further disclosure of construction details or addition to an open-source product library, even if not commercially marketed.
In conclusion, G1/23 clarifies that Article 54(2) EPC does in effect embrace the so-called ‘on sale bar’ of US patent law which also renders commercially available products as prior art. Strategic use of trade secrets remains worthy of consideration in some instances with knowledge that patentability can only reside in non-obvious developments from a marketed product.
