G 1/23 Referral - Is a marketed product prior art?

The question of whether something is made available to the public is fundamental to patent law. Article 54(1) EPC states that "An invention shall be considered to be new if it does not form part of the state of the art". Article 54(2) EPC then goes on to define what constitutes the state of the art, which is "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". A product that is put on the market is made available to the public either by use or "in any other way", so such a product becomes part of the state of the art once on the market. A later filed patent application claiming the same product would consequently not be novel. 

There is a difference, however, between making available a product by placing the product itself on the market and making the same product available to the public by way of a disclosure, for example by publication of a paper or a patent application. In the latter case, the product itself is not disclosed but is only made available to the public if a skilled person would be able to reproduce the product based on what is disclosed. In other words, the disclosure needs to be enabling. This requirement does not (or at least should not) apply to a disclosure by placing the product on the market simply because the product itself is made available. Consequently, disclosure of the product by placing it on the market does not necessarily disclose to the skilled person how to make the product, while disclosure by publication is in effect the reverse, in that the disclosure must disclose to the skilled person how to make the product. 

Given the above, is there any question to be answered regarding whether a product is considered to be made available to the public if the skilled person might not be able to reproduce the product itself? One might think not, but this is in fact a live question that has been put before the EPO Enlarged Board of Appeal. Technical Board of Appeal decision T 438/19 has raised the following questions:

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?

Only question 1 is really of any significance. If this is answered in the negative, the other two questions are essentially pointless and don't add anything. Since it should be obvious by now that I think the answer to the first question should be a clear 'no', I will not even say anything about the other two. 

A first important point to note, which is key to answering question 1, is that it relates to a product and not to a method for making a product. In the patent in question, the product is a “material suitable as an encapsulating material for [a] solar cell” (claim 1 of the patent). The claims of the patent relate only to: i) the material itself; ii) a solar cell comprising the material; and iii) use of the material as an encapsulating material for a solar cell. There is no question regarding a method of making the material or whether such a method was made available to the public at any point. 

A second important point to note is that the alleged differentiating feature in claim 1 of the patent is only the final feature of claim 1, which is “a content of aluminum element of from 10 to 500 ppm”, the purported closest prior art disclosing all other features. Therefore, if the purported closest prior art is considered not to be excluded from the state of the art within the meaning of Article 54(2) EPC, the only question to be addressed is whether increasing the aluminum content to a value within the stated range would be obvious to the skilled person, and not whether a process of making the product in this way would be available to the skilled person. 

Thirdly, although the question of validity of the patent is one of inventive step, the question before the Enlarged Board is one only of novelty, i.e. whether the product was made available to the public before the priority date of the patent. The finding of the Enlarged Board will therefore have an effect on any case relating to whether putting a product on the market makes the product part of the state of the art for novelty or inventive step.

As a general principle, as outlined above, if a product has been put on the market and therefore made available to the public, any claim to the product itself in a later filed patent application would lack novelty. A distinction should be made between a claim to a product and a claim to a method of making the product. The former claim would be invalid over the making available to the public of the product, regardless of how the product was produced or whether the skilled person could have reproduced the product. The latter claim would only be invalid if the method of making the product was known by, or would be obvious to, the skilled person. A new method of making an existing product is patentable. The product itself produced by any other method cannot be patented a second time. 

The referral in this case stems from the following paragraph from the Enlarged Board’s reasoning in G 1/92: 

"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” (point 1.4 of the reasons). 

The referring board in T 438/19 indicates that the last sentence of the above passage “could appear to indicate that a product put on the market becomes state of the art and therefore available to the public only when the composition or internal structure of the product can be discovered and reproduced without undue burden” (point 8.2 of the reasons). This would, however, in my view be a misreading of both the sentence itself and the context in which it is used, which is in relation to whether a product can be reproduced. The sentence is only referring to the situation where, if the skilled person can reproduce the product without undue burden, both the product and its composition or internal structure become state of the art. The product itself is state of the art regardless of whether its composition or internal structure could be analysed, not least because the product in the same form would be an infringement of a claim to the product if placed on the market afterwards. The reference in G 1/92 to the skilled person being able to “reproduce it without undue burden” is therefore clearly referring to the skilled person being able to deduce how to “prepare the said product”, not to whether making the product available to the public before the priority date would be prior art for a claim to the product itself. This is regardless of whether the skilled person could reproduce the product with or without undue burden. The answer to question 1 must therefore be no. 

For a claim to a product, it does not matter whether the skilled person could or did reproduce the composition or internal structure of the product if the same product would be considered infringing if put on the market afterwards. A good example of this is the case of Merrell Dow Pharmaceuticals Inc. v H.N. Norton & Co. Ltd. [1996] RPC 76, a judgment from the UK House of Lords. The key finding of this was that a product (in this case an acid metabolite of an anti-histamine drug terfenadine) was made available to the public before the priority date of a patent to the product because it was an inevitable consequence of taking the drug terfenadine. Although the composition of the acid metabolite product was not made available to the public until after the filing date of the patent in question, following further research by the patentee, this did not matter. This was because, as Lord Hoffmann put it, “one cannot swallow terfenadine without shortly afterwards making the acid metabolite in one’s liver” (paragraph 7). Lord Hoffmann then quoted the Enlarged Board decision in G 2/88 (Mobil), which stated: “It is generally accepted as a principle underlying the EPC that a patent which claims a physical entity per se, confers absolute protection upon such physical entity; that is, wherever it exists and whatever its context (and therefore for all uses of such physical entity, whether known or unknown)” (point 5 of the reasons). Lord Hoffmann then went on to state that the consequence of this is that: “If the use would have been an infringement afterwards, it must have been an anticipation before”. (paragraph 25). If the Enlarged Board in G 1/23 were to find that such a principle was no longer applicable, this would allow patent claims to products already put on the market, thereby turning something that would previously not be an infringing product into an infringement. It ought to be clear that this would be a nonsense, and should not even require considering provisions such as Section 64 to allow what was done before to be continue to be done. I hope that the Enlarged Board see this and decide accordingly.