In T 254/93 (OJ 1998, 285) an application relating to the use of a retinoid compound in association with the use of corticosteroids in the prevention of skin atrophy was refused by the examining division. The board noted that it was a basic consideration in G 2/88 (OJ 1990, 93) that the recognition or discovery of a previously unknown property of a compound, such property providing a new technical effect, could involve a valuable and inventive contribution to the art. The board stated that it had no difficulty in accepting that the prevention of skin atrophy had to be regarded as a pharmaceutical feature and, following the conclusions of the Enlarged Board of Appeal, that the effect underlying this feature was not made available to the public in written form by any of the cited literature. Nevertheless, the question arose whether, in the case at issue, this effect was a technical effect within the meaning of decisions G 2/88 and G 6/88 (OJ 1990, 114), which was necessary to establish novelty, under Art. 54(1) EPC 1973, of the claimed subject-matter over the prior art. Although it concerned a specific aspect of the known use, the use specified in claim 1 (prevention of skin atrophy) was not actually different from the known use (treatment of dermatoses). The board observed that when a second medical indication was claimed in relation to the use of a constituent in the preparation of a known composition and the final effect was apparent in using the known composition for the known purpose, a technical problem could be seen neither in the obtaining of the final effect nor in the preparation of the composition. The only remaining question could be the explanation of the phenomenon underlying the treatment according to the known process. However, the mere explanation of an effect obtained when using a compound in a known composition, even if the explanation related to a pharmaceutical effect which was not known to be due to that compound in the known composition, could not confer novelty on a known process if the skilled person was already aware of the occurrence of the desired effect when applying the known process (see also T 669/01, T 605/09, improvement of activity in a pet is not a new technical effect in terms of G 2/88; T 433/11).

Similarly, in T 486/01 the physiological effects highlighted by the patent proprietor were only regarded as additional items of knowledge about a further mechanism of action underlying the known therapeutic application.

In T 385/07 claim 1 was drafted in the form of a second/further medical use of aplidine for making a medicament for the treatment of a mammal affected by pancreatic cancer. The relevant issue was whether or not this use related to a novel medical use within the meaning of decision G 5/83 (OJ 1985, 64). The board found that, following decision T 158/96, the information in a citation that a medicament was undergoing a clinical phase evaluation for a specific therapeutic application was not prejudicial to the novelty of a claim directed to the same therapeutic application of the same medicament if the content of said citation did not allow any conclusion to be drawn with regard to the actual existence of a therapeutic effect or any pharmacological effect which directly and unambiguously underlay the claimed therapeutic application. It was true that the present application related to in vivo results in mice, not humans. However, it was an accepted principle of the case law that, for the purpose of patent protection of a medical application of a substance, a pharmacological effect or any other effect such as an effect observed on animal models was considered to provide sufficient evidence of a therapeutic application if, for the skilled person, this observed effect directly and unambiguously reflected such a therapeutic application (see e.g. T 241/95, OJ 2001, 103). Applying this principle, the board accepted in the case at issue that, in the absence of any data on human patients, the in vivo experiment was sufficiently predictive of the in vivo anti-tumour activity in humans.