Under R. 28(c) EPC (R. 23d(c) EPC 1973), European patents may not be granted in respect of biotechnological inventions which concern "uses of human embryos for industrial or commercial purposes". The expression "uses for industrial or commercial purposes" in R. 28(c) EPC covers the making of the claimed product, even where it was intended to use that product for further research (G 2/06).

In G 2/06, the Enlarged Board considered an invention concerning, inter alia, human embryonic stem cell cultures which at the filing date could only be prepared by a method which necessarily involved the destruction of the human embryos from which they were derived, that method not being part of the claims.

When interpreting R. 28(c) EPC, the Enlarged Board also looked at Art. 6(2) Biotech Directive because the aim of introducing R. 26 to 29 EPC was to align the EPC to that directive. It observed that neither the EU legislator nor the EPC legislator, unlike their German and UK counterparts, had chosen to define the term "embryo". It assumed that they had been aware of the definitions in national laws on regulating embryos and deliberately refrained from defining the term. Given the aim of protecting human dignity and preventing the commercialisation of embryos, it could only presume that "embryo" was not to be construed restrictively and therefore rejected the appellant's argument that "embryo" was to be given a very specific interpretation as meaning embryos of 14 days or older, in accordance with usage in the medical field.

The appellant had argued that, for the R. 28(c) EPC prohibition to apply, the use of human embryos had to be claimed. The Enlarged Board disagreed, observing that R. 28(c) EPC did not mention claims, but rather referred to "invention" in the context of its exploitation. What had to be looked at was not just the explicit wording of the claims but the technical teaching of the application as a whole as to how the invention is to be performed. The Enlarged Board thus answered the second point referred as follows: R. 28(c) EPC forbids the patenting of claims directed to products which – as described in the application – at the filing date could be prepared exclusively by a method which necessarily involved the destruction of the human embryos from which the said products are derived, even if the said method is not part of the claims.

In T 522/04, the contested claim was directed to a method of proliferating in vitro a clonal population of neural crest stem cells of mammalian origin. This clearly included cells of human origin. Since the only teaching of how to prepare human neural crest stem cell cultures was the use (involving their destruction) of human embryos, the board concluded that at the filing date human neural crest stem cells could be prepared exclusively by a method which necessarily involved the destruction of human embryos – with the inescapable result that the invention fell under the prohibition of Art. 53(a) EPC combined with R. 28(c) EPC.

In T 2221/10 claims 1 and 2 of the appellant's sole request referred to methods of maintaining human embryonic stem cells (hES cells) in culture in an undifferentiated state, while claim 5 referred to a cell culture comprising hES cells. The appellant argued that methods using commercially or otherwise publicly available hES cell lines were not excluded from patentability because no de novo destruction of human embryos was necessary to perform them.

The board disagreed. It referred to G 2/06 and noted that, according to that decision, all steps preceding the claimed use of hES cells which are a necessary precondition for carrying out the claimed invention have to be considered. In this respect the Enlarged Board of Appeal had neither made a distinction between steps which have been carried out by the inventor or by any other person, nor between steps which took place in direct preparation of the experiments leading to an invention and steps having taken place at a point in time further remote from those experiments. The board thus decided that inventions which make use of hES cells obtained by de novo destruction of human embryos or of publicly available hES cell lines which were initially derived by a process resulting in the destruction of the human embryos are excluded from patentability under the provisions of Art. 53(a) EPC in combination with R. 28(c) EPC. It noted that its decision was in line with ECJ judgment C-34/10.

In T 1441/13 claim 1 of the main request was directed to a method for obtaining polypeptide-secreting cells. The method required the use of a culture of primate pluripotent stem cells (pPS) which, according to the description in the application, included human embryonic stem (hES) cells. The board considered that at the relevant date of the patent in suit, the known and practised method for achieving cultures of hES cells, i.e. the starting material of the method of claim 1, included preceding steps that involved the destruction of human embryos. Thus, the main request was not allowable under Art. 53(a) EPC and R. 28(c) EPC.