Update on the patentability of stem cells

(Regarding case C-34/10 Brüstle vs. Greenpeace eV)

The use of human stem cells in research has always been controversial because they are usually sourced from a portion of the human embryo and because they are the fundamental cells which have the ability to develop into any cell of the human body. Nonetheless, due to the huge potential for application of stem cells in medicine, for example, the creation of replacement organs (such as kidneys), the interest in patenting such research is increasing, and with it, questions about the morality of such patents.

The recent case of Brüstle vs. Greenpeace should give some guidance from the EU Courts as to what is patentable with respect to human stem cells. The dispute originated because Mr. Brüstle’s patent for the treatment of diseases such as Parkinson’s uses pluripotent neural precursor cells, which Greenpeace contested is a violation of ethics and morality. During the case at the German Federal Court, several questions regarding the definition and use of ‘human embryos’ were referred to the Court of Justice of the European Union (CJEU).

In the CJEU, before the decision of the court, the Advocate General M. Yves Bot issued a legal opinion in March on the questions referred.  The  Advocate General  gave his opinion that totipotent stem cells are legally classified as part of human embryos, and must be excluded from patentability. Further to this, pluripotent stem cells are only acceptable if they have not been isolated at the detriment of a human embryo. Within the embryo, ‘totipotent’ refers to the stem cells that are produced at the earliest stages of development following fertilization that can differentiate into all embryonic and body cells. Pluripotent cells are cells produced at the later blastocyst stage of the embryo and have undergone some specialization such that they can no longer differentiate into all types of cells in the body.

The basis of this decision came from the wording of the Biotech Directive, wherein Article 5(1) protects “the human body, at the various stages of its formation and development”. Mr. Bot was of the opinion that development must be analysed scientifically, and in which case, development begins at fertilization. Mr. Bot therefore declared that totipotent cells must come under the definition of an ‘embryo’ because they are capable of producing an entire human being, and are therefore excluded from patentability. This definition extends to cover those cells that have been created by somatic cell nucleus transfer, or parthenogenesis to stimulate division of unfertilized ova. Mr. Bot also considered that pluripotent stem cells do not themselves fall under the definition of embryo, since they can only differentiate into certain organs, but if they have been produced by the destruction or modification of an embryo, then they are not patentable. Considering this, Mr. Brüstle’s appeal at the German Federal Court is likely to be rejected and the patent revoked on the basis that it uses pluripotent neural cells derived from the destruction of embryos.

It remains unclear whether this opinion extends to all inventions that relate to use of previously isolated pluripotent cells or established cell lines, even if the process described does not itself reference the use of embryos. Mr. Bot only states that where the application of the technical process claimed in a patent necessitates the prior destruction of embryos it shall not be allowed. Mr. Bot further clarified that inventions relating to the treatment or diagnosis of diseases within embryos shall not be affected. In practice, the Court of Justice may take more of a middle ground, allowing inventions relating to the use of existing cell lines where the act of creating the cell lines by destruction of an embryo is not claimed.

This opinion of the Advocate General is not legally binding on the CJEU, but in general the majority of judges would tend to follow its advice. We will, now however, wait for the decision of the judges of the CJEU.  This opinion, if followed, is therefore likely to permeate into decisions taken in the future by the EPO and other European patent offices, providing a more unified position on stem cell patents.

For more information or advice on the issues raised in this article please contact, Philip French, Head of Biotechnology at Appleyard Lees.