The cases decided following decision G 5/83 throw some light on the categories of novel and inventive therapeutic use for which the manufacture of a known substance or compound may be considered patentable. Manufacture of a known composition has been considered patentable for use in a new therapy where the target group to be treated was different (seronegative pigs instead of seropositive pigs; T 19/86, OJ 1989, 25), and in the case of a new therapy with a different technical effect (prevention of tooth decay by means of a known substance, but by removing plaque instead of by reducing the solubility of tooth enamel; T 290/86, OJ 1992, 414) or a new therapy with a different mode of administration (subcutaneous instead of intramuscular injection; T 51/93). However, some boards of appeal have regarded the acceptance of patentability in principle as problematic where the specific therapeutic use differing from the prior art is a mere dosage regimen.
With reference to the case law and the danger of a collision with Art. 52(4) EPC 1973, decision T 584/97 denied patentability for a claim directed essentially to the administration of nicotine in increasing doses. In T 317/95, T 56/97 and T 4/98 (OJ 2002, 139) the issue was discussed, with answers tending towards the negative, but ultimately left undecided. In all of these cases, the grant of a patent would anyway have been refused on other grounds - i.e. lack of novelty or inventive step - so that the outcome of a decision on this issue was immaterial (see also T 1319/04, OJ 2009, 36)
In T 1319/04 (OJ 2009, 36), the board noted that the legal question whether medicaments for use in methods of treatment by therapy, where the only novel feature was a dosage regime, are patentable under Art. 53(c) EPC and Art. 54(5) EPC, was an important point of law, as the situation arose quite frequently. If patenting was to be excluded in such circumstances, then applicants needed to know this for certain. Accordingly, the board referred to the Enlarged Board of Appeal questions which were answered in G 2/08 (OJ 2010, 456) as follows:
1. Art. 54(5) EPC does not exclude a medicament which is already used in the treatment of an illness being patented for use in a different treatment by therapy of the same illness. Art. 53(c) EPC, which lists as an exception to patentability 'methods for treatment of the human body ... by therapy' is clear and unambiguous, and draws a borderline between unallowable method claims directed to a therapeutic treatment on the one hand and allowable claims to products for use in such methods on the other. The two concepts of a method of treatment by therapy and of a product to be used in such a method are so close to each other, that there is a considerable risk of confusion between them unless each is confined to its own domain as allocated to it by the law. Art. 53(c), second sentence, EPC, is not therefore to be interpreted narrowly; on the contrary, it is appropriate to give both provisions (Art. 54(5) and Art. 53(c) EPC) the same weight and conclude that, in respect of claims directed to therapy, method claims are absolutely forbidden in order to leave the physician free to act unfettered, whereas product claims are allowable, provided their subject-matter is new and inventive. By virtue of a legal fiction, Art. 54(4) and (5) EPC acknowledge the notional novelty of substances or compositions even when they are already comprised in the state of the art, provided they are claimed for a new use in a method which Art. 53(c) EPC excludes from patent protection. The notional novelty, and thus, non-obviousness, if any, is not derived from the substance or composition as such, but from its intended therapeutic use. Art. 54(5) EPC refers to "any specific use" [emphasis added] and thus, in conjunction with the stated intention of the legislator to maintain the status quo of the protection evolved in the case law of the boards of appeal under G 5/83 (OJ 1985, 64) in this respect, this use cannot be ex officio limited to a new indication stricto sensu (approving T 1020/03, OJ 2007, 204).
2. The Enlarged Board went on to hold that such patenting is also not excluded where a dosage regime is the only feature claimed which is not comprised in the state of the art. Given the answer to the first question, and, since Art. 54(5) EPC may be used in cases of the treatment of the same illness, the "specific use" in the sense of that provision may reside in something other than the treatment of a different illness, the Enlarged Board held that there is no reason to treat a feature consisting in a new dosage regime of a known medicament differently from the one given to any other specific use acknowledged in the case law. However, it stressed that the whole body of jurisprudence relating to the assessment of novelty and inventive step also applies. The jurisprudence on this continues to apply (see T 290/86; OJ 1992, 414; T 1020/03, OJ 2007, 204; T 836/01; T 1074/06). In respect of second and further medical indications, the EPC now allows use-related product claims directed to the substance itself, whereas under the EPC 1973, G 5/83 allowed claims directed to the use of a substance for the manufacture of the drug for a therapeutic indication ('Swiss-type claims'). It appears that the rights conferred on the patentee by the claim category under Art. 54(5) EPC are likely to be broader and could lead to possible restrictions on the freedom of medical practitioners to prescribe or administer generics. However, if deemed necessary, the freedom of medical practitioners may be protected by other means on the national level.
In T 1020/03 (OJ 2007, 204) a pure dosage regimen was for the first time recognised as not excluded from patentability. In T 1020/03 the claims were directed to the use of insulin-like growth factor-I in the preparation of a medicament for administering to a mammal in a specific discontinuous administration pattern. Analysing decision G 5/83 (OJ 1985, 64), the board found that any use to which Art. 52(4), first sentence, EPC 1973 applied, in circumstances where the composition had already been suggested for some therapeutic use, would allow a further medical use claim in the approved format, irrespective of the amount of detail in which the use was specified, subject to the use being novel and inventive. The phrase "manufacture of a medicament for a specified new and inventive therapeutic application" used by the Enlarged Board of Appeal merely indicated that the application was restricted in some way to make it novel and inventive over the known therapy using such composition. According to the board, if the subject-matter of the claim avoided the method of treatment by therapy prohibited in Art. 52(4), first sentence, EPC 1973 as would be the case for a claim in the approved "Swiss" form, compliance with this provision did not need to be considered further, and certainly not in order to impose restrictions on the breadth of the claim.
The board argued that there was no interference with the freedom of the physician because the patent proprietor would have a remedy only against the maker of, or dealer in the composition. The fact that the marketing of pharmaceuticals was tightly controlled within the contracting states by the relevant control authorities meant, that for most pharmaceuticals, it could be established for what therapeutic treatment(s) they were marketed. Allowing second medical use patents served to increase the possibility that someone would undertake the necessary research. For these reasons, the board interpreted decision G 5/83 (OJ 1985, 64) as allowing Swiss form claims directed to the use of a composition for manufacturing a medicament for a specified new and inventive therapeutic application, where the novelty of the application might lie only in the dose to be used or the manner of application. Swiss-type claims will no longer be possible (see G 2/08 above).