Under the EPC 1973 a patent for a further medical application could, pursuant to a line of case law first set out in decision G 5/83 (OJ 1985, 64), be granted for a claim directed to the use of a substance or composition for the manufacture of a medicament for a specified therapeutic application ("Swiss-type claim"). The novelty of the subject-matter of such a claim could be derived not only from the novelty of the substance or of the method of manufacture, but also from the new therapeutic application (G 5/83). This "special approach to the derivation of novelty" as it was called in decision G 5/83 constituted a narrow exception to the general novelty requirement and was not to be applied in other fields of technology.
Under Art. 54(4) EPC (former Art. 54(5) EPC 1973), known substances or compositions are deemed to be new, provided they are used for the first time in such a medical method ("first use in a medical method"). In the early 1980s, the Enlarged Board of Appeal was asked to decide whether any further medical use could receive patent protection under the EPC in spite of the wording of Art. 54(5) EPC 1973 (now Art. 54(4) EPC) which seemed to limit patentability to the first medical use. The Enlarged Board extended the notional novelty provided for in former Art. 54(5) EPC 1973 to apply to each further medical use in the so-called "Swiss type claim", i.e. to a claim "directed to the use of a substance or composition for the manufacture of a medicament for a specified new and inventive therapeutic application" (G 5/83, OJ 1985, 64; Legal Advice from the Swiss Federal Intellectual Property Office, OJ 1984, 581).
During the course of the revision of the EPC 2000, former Art. 54(5) EPC 1973 ("first use in a medical method") was renumbered to become Art. 54(4) EPC and a new Art. 54(5) EPC was introduced to provide protection for second medical uses. The new Art. 54(5) EPC eliminates any legal uncertainty on the patentability of further medical uses. It unambiguously permits purpose-related product protection for each further new medical use of a substance or composition already known as a medicine.
This protection is equivalent, as far as the further uses are concerned, to that offered by the Swiss type claim. In contrast to Art. 54(5) EPC 1973 (now Art. 54(4) EPC) which provides broad (generic) protection for the first use in a medical method, new Art. 54(5) EPC is expressly limited to a specific use in such a method. This limitation is intended to match as closely as possible the scope of protection to the scope provided by a Swiss type claim. Claims to a second medical use would be drafted as product claims relating to a specific second or further medical use (see T 1599/06).
The board in T 1099/09 found that it followed clearly and directly from the EPC that Art. 54(4) and (5) EPC applied only to products which were substances or compositions and that no other products were patentable under them. The therapeutic effect of a medicinal product usually resulted from at least one substance or composition used in it and generally known as its active ingredient.
In T 1758/07 the board stated that G 5/83 only applies to second (and further) medical indications. It followed from this that the legal fiction behind G 5/83, namely that the therapeutic treatment according to Art. 52(4) EPC 1973 was a limiting feature, was applicable only if a therapeutic treatment was indeed a second (or further) medical indication. If, however, the claimed subject-matter related to the first medical indication, G 5/83 provided no legal basis for additionally claiming the same subject-matter as a second medical indication.
The Enlarged Board of Appeal has since held in G 2/08 (OJ 2010, 456) that, where the subject-matter of a claim is rendered novel only by a new therapeutic use of a medicament, such claim may no longer have the format of a so-called Swiss-type claim as instituted by decision G 5/83 (OJ 1985, 64). As Art. 54(5) EPC now permits purpose-related product protection for any further specific use of a known medicament in a method of therapy, the loophole existing in the provisions of the EPC 1973 is now closed - when the reason for the law ceases, the law itself ceases. G 2/08 is discussed in further detail in point 6.2.3 b) "Difference in the prescribed administration regime", below. Claims to a second medical use can now be drafted as product claims relating to a specific second or further medical use (see e.g. T 1599/06).
According to Art. 1, No. 3 of the Decision of the Administrative Council of 28 June 2001 under Art. 7 of the Act revising the EPC of 29 November 2000, revised Art. 54(5) EPC is applicable to European patent applications pending at the time of the EPC 2000's entry into force, insofar as a decision on the grant of the patent has not yet been taken (see decision T 1127/05 of 15 January 2008; T 406/06 of 16 January 2008) (see also OJ SE 4/2007).
For the "Formulation of claims under the EPC 1973", see "Case law of the Boards of Appeal of the EPO", 6th edition 2010.