Totipotent cells, blastocysts, pluripotent cells and their proposed legal status as non-patentable embryos. Oliver Brϋstle v Greenpeace eV, Case C-34/10

By Jennifer Jones


Advocate General Bot delivered his opinion on 10 March 2011.  The decision of the European Court is expected before the summer.

Image courtesy of Mike Jones

Totipotent cells appear after the fusion of the gametes and exist in that form for a few days.  They have the unique characteristic that they can develop into a complete human being.  The blastocyst stage of development is reached around five days after fertilization. Pluripotent cells are not capable of developing into a complete human being, but can differentiate into various organs that form the human body.  Pluripotent cells are of significant importance to researchers as they are able to differentiate into unique cell types.  This makes them potentially useful in regenerative medicine, cell therapies, tissue replacement or as cell development research tools.

The law
The EU Directive on Biotechnological Inventions was adopted in 1998 to harmonize patent laws among member states.  It contains recital 16, which establishes the principle that patent law must be applied so as to respect the fundamental principles safeguarding the dignity and integrity of the person; Article 5, which prohibits the patenting of the human body at the various stages of its formation and development; and Article 6, which prevents patents on inventions that are contrary to “public order” or morality.  Article 6 also lists inventions that are not patentable, including cloning humans, processes for modifying the genetic identity of humans through the germ-line, and “uses of human embryos for industrial or commercial purposes”.

The WARF decision
In November 2008 the Enlarged Board of Appeal of the European Patent Office was asked whether, under Article 6, an embryonic stem cell line described in a patent application was patentable.  Importantly, the only method described in the patent application to prepare the cell line included the destruction of human embryos. The Board held not patentable claims directed to products which were prepared exclusively by a method which involved the destruction of the human embryos from which the said products were derived.  The Board refused to consider that after the filing date of the patent the embryonic stem cell line could be obtained without having to destroy the human embryo.

The proposed legal status applied by the Advocate General
According to the AG, totipotent cells represent the first stage of the human body and must therefore be legally categorised as embryos, and consequently are not patentable.  This includes unfertilised ova into which a cell nucleus from a mature cell has been transplanted and unfertilised ova whose division has been stimulated by parthenogenesis in so far as totipotent cells would be obtained. A blastocyst is one of the aspects of the development of the human body and constitutes one of the stages of development.  Accordingly, it must itself be categorised as an embryo, like any stage before or after that development.

Pluripotent cells are not capable of development into a human being and are therefore different.  In isolation, pluripotent cells cannot be regarded as constituting an embryo and are therefore patentable.  In relation to pluripotent cells, the Advocate General stated: “Given that embryonic stem cells, taken in isolation, are no longer capable of developing into a complete individual, they can no longer, in my view, be categorised as human embryos.  These cells have been removed at a certain stage in the development of the embryo and they are not capable, in themselves, of resuming that development.”

However, in line with the WARF decision, if the pluripotent stem cell is removed at some stage in the development of the human body, and the removal results in the destruction of that stage of the human body, the pluripotent stem cell is not patentable.  In Brϋstle, the pluripotent stem cell was removed from the blastocyst, which itself constituted an embryo, and as a result the blastocyst is destroyed.  Accordingly, the Brϋstle pluripotent stem cell should not be patentable.

The opinion of the Advocate General goes further than the WARF Board decision. In the opinion of the Advocate General, inventions relating to pluripotent stem cells can only be patentable if they are obtained without detriment to the embryo, be that an embryo’s destruction, modification or use as a base material.  This would prohibit the patentability of any pluripotent cells obtained from totipotent cells or blastocysts, as both are classified as embryos. 

Since both the WARF patent application (1995) and the Brϋstle patent (1997), new methods have been developed for the production of stem cell lines that do not require the use of human embryos.  These include “induced pluripotent stem cells”, which uses ‘reprogramming’ techniques to induce already differentiated cells to revert back to the pluripotent state.  As neither the WARF decision, nor the AG opinion, prohibits the patenting of stem cells that do not involve the use of human embryos, should the European Court follow the opinion of the Advocate General, induced pluripotent stem cells would be patentable.  Patent protection can still be sought for claims to the research methods used, which are continuously developing in this area.  Further, given the specialised nature of the research techniques used, often the competitive position of a company in relation to stem cells is dependent more on know-how than patent protection.