SONN Patentanwälte – IP Attorneys

EPO case law: Novelty due to high degree of purity

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. The jurisprudence established by earlier EPO BoA decisions – in particular T 990/96 and T 728/98 – on the present question cannot therefore be maintained on closer examination of the EPO EBA decisions G 2/88 and, above all, G 2/10 (EPO BoA 9 November 2018, T 1085/13).