The possibilities of obtaining patent protection in Europe for inventions relating to human embryonic stem cells (hESCs) have been significantly curtailed in recent years, particularly by decision C34/10 of the Court of Justice of the EU (CJEU) (see here for a recent report).  However, the Advocate General has recently issued an opinion in pending case C364/13, which, if followed, might open new opportunities for patent applicants. In Europe, inventions relating to industrial or commercial uses of human embryos are excluded from patentability(1), so it is important to establish what is meant by the term "embryo".

The CJEU previously ruled(3) that any human ovum after fertilisation, any non-fertilised human ovum into which the cell nucleus from a mature human cell has been transplanted, and any non-fertilised human ovum whose division and further development have been stimulated by parthenogenesis (referred to for simplicity as a "parthenote") constitute a human embryo.

However, the CJEU’s judgement was based on the premise that parthenotes are capable of commencing the process of development of a human being. This premise was scrutinised in a case before the UK High Court, International Stem cell corporation vs Comptroller General of Patents(2), resulting in a further referral to the CJEU to decide the following question:

‘Are unfertilised human ova whose division and further development have been stimulated by parthenogenesis, and which, in contrast to fertilised ova, contain only pluripotent cells and are incapable of developing into human beings, included in the term "human embryos" in Article 6(2)(c) of Directive 98/44 on the Legal Protection of Biotechnological Inventions?’

The Advocate General issued his opinion on 17 July 2014, setting out that he believes that parthenotes should not be regarded as embryos, as long as they are not capable of developing into a human being and have not been genetically manipulated to acquire such a capacity.

The CJEU is not required to adopt the opinion of the Advocate General, but it will be guided by this opinion, so there is a strong likelihood that the final ruling will echo the Advocate General’s comments.