The European Patent Office (EPO) Enlarged Board of Appeal decision G 2/88 is heavily cited in support of the generally accepted principle underlying the EPC that a claim to a particular physical activity (e.g. method, process) confers less protection than a claim to said physical entity as such. In the EPO’s opinion this approach also applies to the 2^nd medical use claims in the outdated “Swiss-type” claim format vs. the new claim format under Article 54(5) EPC 2000.

No wonder: 2^nd medical use claims in the outdated Swiss-type claim format “Use of compound X in the manufacture of a medicament for the treatment of disease Y”, – once categorized by the EPO as purpose limited process claims – , allegedly confer less protection than the purpose-limited product claim format under Article 54(5) of the EPC 2000 “Compound X for use in the treatment of disease Y”. See e.g. Board of Appeal decisions T 1780/02 and T 879/12 in the context of double patenting or decision T 250/05 and recently published decision T 1673/11 in the context of Article 123(3) EPC prohibiting extension of claimed scope post-grant.

By way of background, the intention behind the provision of Article 54(5) EPC 2000 resulting in the new purpose-limited product claim format was originally the filling of a gap in the legal provisions of the EPC 1973 which until EPC 2000 has been closed in a praetorian way by the Enlarged Board of Appeal with decision G 5/83 allowing Swiss-type claims as outlined in great detail in decision G 2/08 and the Travaux préparatoire, CA/PL 4/00, points 6 to 8. In other words, when drafting the EPC 2000 the legislator wished to maintain the status quo, as regards the availability of patent protection for second medical uses, and surely not to create pitfalls under Article 123(3) EPC or opportunities with regard to double patenting of the same invention.

Anyway, the above cited case law establishing new “rules of the game” can be used in favor of the EPO costumers, either by patenting the same invention as per both 2^nd medical use claim formats in separate applications as long as this is possible according to G 2/08 (allowable for applications having a priority date of January 29, 2011 or earlier) thereby affording best possible conditions in infringement proceedings across Europe (see e.g. P. England, “Infringement of second medical use patents in Europe and the UPC”, GRUR Int. 7/2016, pages 714-720), or in opposition proceedings if the question of post-grant claim scope extension arises.