In a ruling that threatens the future of embryonic stem cell research and commercialisation across Europe, the Court of Justice of the European Union (CJEU) held that a patent should not be granted to an invention if its implementation requires the prior destruction of human embryos or their prior use as base material. This ruling is likely to extend to inventions that require the use of immortalised human embryonic stem cell (ESC) lines.

European patent law concerning the patentability of human embryos

The ruling concerns the interpretation of provisions under European patent law (Article 6(2)(c) of Directive 98/44/EC), which exclude from patentability "uses of human embryos for industrial or commercial purposes." Three questions were referred to the CJEU for consideration:

  1. What is meant by the term "human embryos" in Article 6(2)(c) of the Directive?

The CJEU held that a "human embryo" includes (i) a fertilised human ovum, (ii) a non-fertilised human ovum that has had its nucleus replaced with a nucleus from a mature cell and (iii) a non-fertilised human ovum whose division and further development has been stimulated by parthenogenesis

  1. What is meant by the expression "uses of embryos for industrial or commercial purposes"?

The CJEU held that the expression "uses of human embryos for industrial or commercial purposes" will include uses of human embryos for the purposes of scientific research that is the subject matter of the patent application.

  1. Is subject matter unpatentable even if the use of human embryos does not form part of the technical teaching claimed within the patent?

The CJEU held that subject matter should be excluded from patentability where the technical teaching that is the subject of the patent application requires the prior destruction of human embryos or their use as base material, whatever the stage at which that takes place, and even if the claimed invention does not refer to the use of human embryos. This will have a far reaching effect, as it will extend the provision to exclude inventions that are derived from the use of existing human ESC lines.  

Impact on human embryo-derived inventions

We will have to wait to see how the European Patent Office will adopt the ruling of the CJEU in their handling of patent applications in this field. However, there would seem to be little point in applying for a patent in Europe if it would fall foul of the ruling handed down by the CJEU. In the meantime, those wishing to pursue a European patent for an invention that involves the use of stem cells will need to ensure that their patent specification includes an example of the use of stem cells other than human ESC.