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EPO – Disclosure of the invention – Novelty – Purity of a chemical substance as a distinguishing feature

21 Jan 2019

EPO, Technical Board of Appeal 3.3.02, decision of 9 November 2018 in case T 1085/13 – Amorphous Lercanidipine Hydrochloride/Recordati

Since decision T 990/96, OJ EPO 1998, 489, it has been consistent case law of the Boards of Appeal of the EPO that a document disclosing a low molecular chemical compound and its manufacture makes this compound available to the public in all grades of purity as desired by a person skilled in the art, provided that methods for the purification of low molecular organic reaction products such as recrystallisation, distillation, chromatography, etc., which normally can be successfully applied in purification steps, are part of the common general knowledge.

In the reported decision, Technical Board of Appeal 3.3.02 takes the position that the rationale of this case law is not in line with the concept of disclosure as developed by the Enlarged Board of Appeal, in particular in decisions G 2/88 and G 2/10 which set out that “the European Patent System must be consistent and the concept of disclosure must be the same for the purposes of Articles 54, 87 and 123 EPC”. Board 3.3.02 concludes therefrom that there must be at least an implicit disclosure in the state of the art of subject-matter falling within the claimed scope.

Discussing the relevant case law on implicit disclosure, Board 3.3.02 concludes that the skilled person, using his common general knowledge, would understand a feature as implicitly disclosed in a prior-art disclosure only if it is the clear and unambiguous consequence, and hence the inevitable result of what is explicitly derivable from said prior art disclosure. Consequently, common general knowledge can be used in order to assess how the skilled person would understand the disclosure of the prior art but cannot be used to supplement it.

The Headnote of the decision reads:
A claim defining a compound as having a certain purity lacks novelty over a prior-art disclosure describing the same compound only if the prior art discloses the claimed purity at least implicitly, for example by way of a method for preparing said compound, the method inevitably resulting in the purity as claimed.

Such a claim, however, does not lack novelty if the disclosure of the prior art needs to be supplemented, for example by suitable (further) purification methods allowing the skilled person to arrive at the claimed purity.

The question of whether such (further) purification methods for the prior-art compound are within the common general knowledge of those skilled in the art and, if applied, would result in the claimed purity, is not relevant to novelty, but is rather a matter to be considered in the assessment of inventive step.

Reported by Dr. Rudolf Teschemacher, Bardehle Pagenberg

A copy of the decision can be read here.