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EPO Enlarged Board of Appeal Referral - Patentability of Inventions relating to Human Embryonic Stem (hES) Cells

EPO Enlarged Board of Appeal Referral - Patentability of Inventions relating to Human Embryonic Stem (hES) Cells


The EPO has referred a number of questions relating to the patentability of an invention concerning hES cells to the Enlarged Board of Appeal (EBOA). The questions arise from an application by Wisconsin Alumni Research Foundation (WARF) which was considered by the Board of Appeal (BOA) in Decision T1374/04.  


The invention encompassed a method for human stem cell culture, where the cells were initially derived from human embryos. The use of human embryos as a starting material was not claimed but merely described in the application as being indispensable to the invention.


The Decision hinged on the interpretation of Article 53(a) and Rule 23d(c) of the European Patent Convention. According to Article 53(a), inventions which are contrary to public policy or morality are excluded from patentability. Rule 23d(c) excludes biotechnological inventions which concern the use of human embryos for industrial or commercial purposes from being patentable.

The questions referred to the EBOA are as follows:

1) Does Rule 23d(c) EPC apply to an application filed before the entry into force of the rule?

2) If the answer to question 1 is yes, does Rule 23d(c) EPC forbid the patenting of claims directed to products which at the filing date could be prepared exclusively by a method which necessarily involved the destruction of the human embryos from which the product was derived, if the method is not part of the claims?

In WRAF’s case the product is a hES cell culture and the application describes that the method of preparing the culture necessarily involves the destruction of human embryos.

3) If the answer to question 1 or 2 is no, does Article 53 (a) EPC forbid patenting of such claims?

4) In the context of questions 2 and 3, is it of relevance that after the filing date the same products could be obtained without having to recur to a method necessarily involving the destruction of human embryos, for example, derivation from available human embryonic cell lines?

The UK Patent Office (UKPO) has already considered the patentability of inventions relating to hES cells and concluded that the commercial exploitation of pluripotent cells (totipotent stem cells give rise to pluripotent stem cells which are unable to form an entire human body)is not contrary to public policy or morality. Consequently, the UKPO will grant patents for inventions involving such cells provided that the normal requirements for patentability are satisfied.   


If Rule 23d(c) is construed narrowly by the EBOA, whereby a claim which does not specify the use of a human embryo and does not contravene Article 53(a) should be allowed, the patenting of inventions relating to hES cells of a pluripotent nature, not totipotent, is likely to be permitted. This would be in-line with the UKPO. Conversely, if construed broadly, Rule 23d(c) and/or Article 53(a) will, so far as WRAF’s application is concerned, be seen to have been breached and applicants may need to limit the filing of patents related to hES cells to a national level.


The outcome of the referral to the EBOA is likely to be followed by many more disputes relating to hES cell research.


Prior to a decision from the EBOA, clients wanting to file European patent applications relating to hES cells at the EPO should also consider filing a UK patent application so as to ensure some form of protection.