In its ruling dated October 18, 2011 – (Case C-34/10) – the Court of Justice of the European Union had to decide on a referral by the German Federal Supreme Court in a nullity appeal proceedings with respect to a patent of the stem cell researcher Professor Brüstle.

The patent relates to neural precursor cells derived from embryonic stem cells, including stem cells produced from the blastocyst stage of human embryos (hES). The claims do not mention the use of embryos for producing the ES cells. As alternative sources stem cells are mentioned which are derived from unfertilized human egg cells, i.e., embryonic germ cells (EGC) and unfertilized eggs in which a cell nucleus from a mature cell has been implanted (“dolly method”). The nullity action against the patent was exclusively based on Section 2 (2) No. 3 German Patent Act which is identical to Art. 6 (2) lit c Biotech-Directive and stipulates that no patents shall be granted for inventions directed to the use of human embryos for industrial or commercial purposes.

The ECJ ruled that the term “embryo” includes any human egg cell after fertilization and any non-fertilized human egg cell into which either a cell nucleus has been implanted or undergoing parthenogenesis. The ECJ did not decide on the question whether an hES as such represented an embryo (rather, this decision shall be left to the national courts of the Member States). “Industrial or commercial purposes” cover also scientific research and do not overcome the exclusion from patentability. The exclusion from patentability does not depend on the fact that the prior destruction of human embryos is not contained in the claims. Even if the destruction is not mentioned in the specification at all, exclusion from patentability applies.

The decision of the ECJ does not distinguish between hES inventions which exclusively rely on the destruction of human embryos and hES inventions which can be carried out using hES cell lines. All of them are being excluded from patentability based on the ruling of the ECJ. Furthermore, the ECJ decision does not affect the patentability of iPS (induced pluripotency stem cells) cells which have ES-like pluripotency but which are derived from human reprogrammed adult cells.

The decision of the ECJ is especially unfortunate in view of the fact that this year the first clinical trials in Europe for a drug on the basis of hES cells have been approved for the company ACT. The decision may have a negative impact on future research in this field of technology since the research results can no longer be patent protected and the pharmaceutical industry will therefore have a reduced interest in funding hES research in Europe.