In decision T 0719/12, an EPO Board of Appeal was asked to consider whether or not the disclosure of a compound by name, together with an apparent failed attempt at its synthesis, constituted a novelty-destroying disclosure of that compound.

The patent at issue included two claims relating to compounds containing an amine group.The respondent to the appeal (who had successfully argued for revocation of the patent at opposition) claimed that the invention according to these claims lacked novelty in view of an academic journal article from 1942 (D1). For an invention to lack novelty, two criteria need to be fulfilled. Firstly, the invention must be disclosed in a single prior art document. Secondly, that disclosure of the invention must be enabling – that is, a skilled person must be able to put the invention into practice on the basis of the disclosure and their common general knowledge. A secondary amine that falls under the general formulae of the claims was indeed disclosed by name in D1, a fact which neither party disputed. However, the parties disputed whether or not the disclosure would have enabled the skilled person to prepare the compound.

D1 is concerned with the synthesis of various amines. Due to the increased reactivity of secondary amines compared to primary amines, it is common for a primary amine to react once to form a secondary amine, and then further react to produce a tertiary amine. D1 reports an attempt to synthesise a secondary amine that falls under the general formulae of the claims. The compound is named, but it is clear from D1 that, despite attempting its synthesis, only the corresponding tertiary amine was isolated. Further attempts to convert the tertiary amine back to the secondary amine failed. Accordingly, the proprietor argued that the disclosure of D1 would not have enabled the skilled person to synthesise the named compound, and so the claims are novel.

The respondent’s main argument was that D1 did, in fact, provide an enabling disclosure of the named compound. The respondent claimed to have followed the procedure described in D1 and to have managed to isolate the named compound. Furthermore, they argued that there were other reaction routes available to the skilled person which could have been used to synthesise the compound. The respondent filed several documents related to these other reaction routes. The proprietor, however, counter-argued that the respondent’s attempt to repeat of the procedure of D1 was flawed – the reactants were heated using a different method, a further treatment was performed, and techniques which were not available to the skilled person at the time that D1 was published were used in their analysis. Accordingly, the proprietor argued that the repeated experiment was performed with the benefit of hindsight and should not be considered. Regarding the use of other routes to synthesise the compound, the proprietor contended that the cited documents were irrelevant as they did not relate to the specific compound, and that numerous documents needed to be combined to arrive at the proposed route.

In its decision, the Board agreed with proprietor, stating that despite conditions “favouring the formation of the secondary amine…only the tertiary amine could be isolated… [and] no evidence could be obtained that the secondary amine was formed”. Regarding the respondent’s repeat of the experiment, the Board held that “it has not been shown that, on repeating the preparation of [the compound] exactly according to the method of D1… that the skilled person could not have overseen the formation of [the compound]. Thus, even if said compound had been present… this fact cannot be deduced from reading D1 alone... Hence, even if [the compound] were inevitably produced by the method described in D1, since its presence remained undetected by the skilled person, it has not been made available to the public.” The Board therefore set aside the decision to revoke the patent for lack of novelty and the case has been remitted to the Opposition Division for further consideration.

This decision builds on T 0206/83 (Herbicides), in which a document was not considered to be an enabling disclosure of a compound despite disclosing the compound’s structure and the synthetic route by which it was produced. The Board’s reasoning was based on the fact that the skilled person would not have been able to prepare the starting materials for the synthetic route using the teaching of the document or common general knowledge.

These two decisions reinforce the strict and objective nature of novelty analysis, which is a fundamental aspect of patent law at the EPO and throughout the world.