Stem cell research involves the use of embryonic stem cells (as well as adult stem cells) in research. As the embryonic stem cells used in research are derived from animals, including humans, stem cell research has become associated with ethical, moral and religious concerns. An issue which has arisen from those concerns is whether inventions which involve stems cells and their uses should be patentable.

The Biotechnology Directive

Patentability confers protection and commercial advantages for a patent owner. However, not all inventions are patentable. The Biotechnology Directive provides that the human body at the various stages of its formation and development, and the simple discovery of one of its elements, cannot constitute patentable inventions. Further, Article 6(2)(c) of the Biotechnology Directive expressly provides that the use of human embryos for industrial and commercial purposes is unpatentable.

Questions however remain: If uses of "human embryos" are not patentable, are stem cells derived from human embryos patentable or are methods of use of stem cells derived from human embryos patentable? In fact, what is meant by the term "human embryos" under the Biotechnology Directive?

The question of what constitutes a human embryo for the purposes of Article 6(2) (c) of the Biotechnology Directive was considered in the case of Oliver Brustle v Greenpeace ("Brustle").

The CJEU's decision in Brustle

Mr Brustle was the owner of a German patent concerning isolated and purified neural precursor cells. His patented invention used pluripotent embryonic stem cells (stems cells which are capable of developing into many different types of specialised cells but not all) to produce isolated and purified precursor cells which could be used in the treatment of neurological diseases such as Parkinson's disease. Greenpeace applied to revoke Mr Brustle's patent. The German court referred questions to the Court of Justice of the European Union ("CJEU") concerning, amongst other things, the meaning of (i) "human embryos"; and (ii) "uses of human embryos for industrial or commercial purposes" within the meaning of Article 6(2)(c) of the Biotechnology Directive.

The CJEU said that the concept of human embryos must be understood in a wide sense. In the court's opinion, the following constituted "human embryos":

  • A human ovum as soon as it is fertilised, if that fertilisation is such as to commence the process of development of a human being;
  • A non-fertilised human ovum into which the cell nucleus from a mature human cell has been transplanted;
  • A non-fertilised human ovum whose division and further development have been stimulated by parthenogenesis (if it is capable of commencing the process of development of a human being just as an embryo created by fertilisation could do).

However, disappointingly, the CJEU said it was for the referring court to decide whether a pluripotent stem cell removed from a human embryo at the blastocyst stage of development constituted a human embryo within the meaning of Article 6 (2)(c).

What are stem cells and why are they important for research?

Stem cells are unspecialised cells which have the ability to divide (proliferate), thus creating a supply of new identical (daughter) cells that, once divided, may develop into cells specialised for particular functions (for example, muscle cells, nerve or brain cells). It is this potential to proliferate and develop into specialised cells (and the manner in which proliferation and specialisation are regulated) which makes stem cells so important for medical research and the treatment of disease.

The law

In the UK, the use of stem cells in medical research is understandably subject to regulatory constraints. In addition, the patentability of inventions relating to stem cell research is subject to the provisions of the Directive on the legal protection of biotechnological inventions (the "Biotechnology Directive").

Although Mr Brustle's invention did not mention the use of human embryos, the stem cells were obtained at the blastocyst stage and at that time the removal of the cells resulted in the destruction of the embryo. The CJEU decided that an invention was to be excluded from patentability where the procedure required the prior destruction of human embryos or the use of human embryos beforehand, as base material, thus removing a possible loophole available where a patent application was silent as to the use of human embryos.

Concerning the question as to what is meant by "use of human embryos for industrial or commercial purposes", the CJEU said that scientific research involving the use of human embryos was not distinguishable from industrial and commercial use and therefore such scientific research use is not patentable. Following the CJEU's ruling, the case went back to the German court for final resolution. The German court followed the CJEU's reasoning but concluded that the Brustle patent was not entirely invalid. It held that stem cells removed at the blastocyst stage did not constitute "human embryos" as such cells, although pluripotent and capable of developing into different kinds of tissues, were incapable of developing into a complete human body. Therefore, if such cells could be produced without destroying the blastocyst (i.e. the "human embryo"), patent protection may be possible.

What does Brustle mean for future stem cell inventions?

Following the decision in Brustle, in 2012 the European Patent Office ("EPO") published new guidelines on the subject of patenting stem cell inventions. The new guidelines follow Brustle and make clear that a stem cell invention should not be directed to a human embryo nor should the invention have required prior destruction of a human embryo. Inventions relating to adult stem cells or human induced pluripotent stem cells or a method of removal of embryonic stem cells without destroying the embryo (a method of doing so was published in 2008) should be eligible for patent protection.

In 2013, the UK High Court in International Stem Cell Corporation v Comptroller General of Patents made a reference to the CJEU requesting clarification of the term "human embryos" in Article 6(2)(c). The High Court asked whether "human embryos" include 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 themselves of developing into human beings.

On the face of it, International Stem Cell Corporation's patent applications claimed methods in which an unfertilised oocyte was activated by parthenogenesis and caused to develop into a blastocyst-like structure used to produce stem cells. Following Brustle, such an invention amounted to commercial or industrial use of a human embryo and as such was unpatentable. However, the applicant had argued before the UK Intellectual Property Office that in Brustle the CJEU was incorrect to find that an oocyte stimulated by parthenogensis was as capable as a fertilised ovum of producing a human being and, further, the applicant provided evidence that an oocyte stimulated by parthenogenesis could not ever develop into a human being.

The decision of the CJEU is awaited with interest. Stem cells without doubt have significant potential for treatment of disease. If inventions relating to cells which will never be capable of developing into a viable human being are to be excluded from patentability, the resulting commercial disadvantage for the biotechnology industry is likely to negatively impact the viability of future stem cell research and may have serious implications for the future management and treatment of disease.

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