In T 250/05 the board held that, apart from the fact that Art. 54(5) EPC (entry into force 13 December 2007) did not apply to a patent granted in 2001, Art. 123(3) EPC would not allow the change of category of a granted use claim into a product claim, even if drafted as a purpose-related product claim. Therefore, in the case at issue, the amended claims had to remain in the "Swiss form" in order not to contravene Art. 123(3) EPC.
In T 1780/12, in the context of double patenting, the board understood that the board in T 250/05 had considered that the scope of protection conferred by a purpose-related product claim was in fact larger than the scope of protection conferred by a Swiss-type claim. See also T 879/12.
In T 1673/11 claim 1 of the main request was drafted in the format of a purpose-limited product claim as provided for by Art. 54(5) EPC, whereas all claims as granted had been in the so called "Swiss-type" form. For the respondent, the protection conferred by both types of claims was the same. The board disagreed. The purpose-limited product claim conferred protection on the product, whenever it was being used for the treatment of infantile Pompe's disease. Since the claim did not refer to a step of manufacture of a medicament, the product claimed was not limited to a manufactured medicament, packaged and/or with instructions for use in the treatment of infantile Pompe's disease. Even if by virtue of Art. 64(2) EPC the protection conferred by granted claim 1 extended to the product directly obtained by the manufacturing process referred to in said claim, the protection conferred by claim 1 of the main request was broader. Nor could the board follow the appellant's argument that since the use limitation of the claims of the main request and of the granted claims was the same, their scope of protection was identical. For example, once the patent was amended, a medicament containing the product, packaged and provided with instructions for the use in a treatment other than that of infantile Pompe's disease was encompassed by the scope of claim 1 of the main request when said medicament was being used for the treatment of infantile Pompe's disease. The protection conferred by granted claim 1 did not encompass such use. The board concluded that the amendment of the contested patent in such a way extended the protection it conferred, contrary to Art. 123(3) EPC.