UK: do parthenotes fall within the term 'human embryo'?


The English High Court referred a question to the CJEU on the interpretation of Article 6(2)(c) of Directive 98/44/EC on the legal protection of biotechnological inventions. The question asked whether a parthenote, which only contained pluripotent cells and was incapable of developing into a human being, was included in the term “human embryo” under Article 6(2)(c) of the Directive.

International Stem Cell Corporation (“ISCC”) had applied for patent protection for methods of producing and isolating pluripotent human stem cell-lines from parthenogentically activated oocytes. On the evidence before it, the Court found that parthenogenesis referred to the initiation of embryogenesis of an oocyte, i.e., cell division leading to the formation of blastocyst, without the involvement of sperm. Although the initial stages of development of a parthenote is similar to that of fertilised ova, they are not identical at any stage. The parthenote's lack of paternal DNA affects genomic imprinting, which means it can never develop into a viable human being and does not contain any totipotent cells.

In case C-34/10 (Oliver Brüstle v Greenpeace eV [2012]), Advocate-General Bot had differentiated between totipotent cells, which have the capacity to develop into a full human being and pluripotent cells which do not. However, in Brüstle, there was no consensus in the written observations on the subject of the development potential of parthenotes. In Brüstle, the CJEU held that the concept of “human embryo” under Article 6(2)(c) must be understood in a wide sense and held that “a non-fertilised human ovum whose division and further development have been stimulated by parthenogenesis” should be regarded as a human embryo. Although not fertilised, the CJEU stated that on the evidence before it, it was apparent that a parthenote was “capable of commencing the process of development of a human being just as an embryo created by fertilisation of an ovum can do so” (see paragraphs 32 to 38).

The Judge agreed with ISCC's submission that if the process of development was incapable of leading to a human being, which the English Court had found in this case in relation to parthenotes, then it should not be excluded from patentability as a “human embryo”. Noting that a balance needed to be struck between the encouragement of potentially life-saving and revolutionary stem cell research and the need to respect the fundamental principles of safeguarding the dignity and integrity of the person, the Judge expressed his view that excluding processes of development which were incapable of leading to a human being did not strike that balance.