In general, the EPC allows both method claims and use claims, but whether any activity is claimed as a method of carrying out the activity (setting out a sequence of steps) or as the use of a thing for a stated purpose (the sequence of steps being implied) is a matter of preference. For the Enlarged Board of Appeal there is no difference of substance (G 5/83, OJ 1985, 64).
Two referrals to the Enlarged Board raised the general issue of novelty of a second non-medical use which was not connected with the specific problems of use claims in the medical field.
In the non-medical field use claims are admissible and not subject to special conditions. In T 231/85 (OJ 1989, 74) the board had to judge the novelty of a second non-medical use in a special constellation. It held that the fact that a substance was known could not preclude the novelty of a hitherto unknown use of that substance, even if the new use did not require any technical realisation other than that for a previously known use of the same substance. In the case in question the known use was use as a growth regulator and the new one, now claimed by the applicant, use as a fungicide. The technical realisation was in both cases the spraying of useful plants.
Later, the same board, with a different composition, referred to the Enlarged Board the question whether a claim for the use of a compound for a particular non-medical purpose was novel under Art. 54 EPC 1973, having regard to a prior publication which disclosed the use of that compound for a different non-medical purpose, so that the only novel feature in the claims was the purpose for which the compound was used. The specific problem in these cases was that the previously disclosed use of the substance, although specifically stated to be for another purpose, would inherently comprise the use as claimed in the new application (T 59/87, OJ 1988, 347; T 208/88 of 20.7.1988).
In decisions G 2/88 (OJ 1990, 93) and G 6/88 (OJ 1990, 114), the Enlarged Board stated that the patentability of a second non-medical use of a product was already recognised in principle in G 5/83 (OJ 1985, 64) which concerned the second medical use of a substance. However, in that earlier decision the exclusion from patentability of therapeutic and diagnostic methods had caused the Enlarged Board to allow only a special type of claim. These specific difficulties did not arise in the non-medical field; there the question was of a general nature, concerned primarily with the question of the interpretation of Art. 54(1) and Art. 54(2) EPC 1973. In G 2/88 and G 6/88, therefore, it was pointed out that a claimed invention lacked novelty unless it included at least one essential technical feature which distinguished it from the state of the art. A basic initial consideration, when deciding upon the novelty of a claim, was therefore to analyse it in order to determine its technical features. The Enlarged Board took the view that the proper interpretation of a claim whose wording clearly defined a new use of a known compound would normally be such that the attaining of a new technical effect on which the new use was based was a technical feature of the claimed invention. Thus, where the particular technical effect underlying such use was described in the patent, the proper interpretation of that claim would require a functional feature to be implicitly contained in the claim as a technical feature - e.g. the compound actually achieved the particular effect.
The Enlarged Board thus concluded that, with respect to a claim to a new use of a known compound, such new use might reflect a newly discovered technical effect described in the patent. The attaining of such a technical effect should then be considered as a functional technical feature of the claim (e.g. the achievement in a particular context of that technical effect). Had that technical feature not previously been made available to the public by any of the means set out in Art. 54(2) EPC 1973, then the claimed invention was novel, even though such technical effect might have inherently taken place in the course of carrying out what had previously been made available to the public. The final decisions in cases T 59/87 (OJ 1991, 561) and T 208/88 (OJ 1992, 22) both held that the claimed use inventions were novel and inventive.