BioWorld International Correspondent

BRUSSELS, Belgium - The European Patent Office is on the brink of excluding all embryonic stem cells from patent protection. If an initial decision reached last week is confirmed, it could amount to prohibiting patenting human embryonic stem cells in any form.

The ruling arose from a case concerning what is known as the "Edinburgh" patent - a patent held by the University of Edinburgh on a laboratory technique for isolating, enriching and selectively propagating animal stem cells. The protection extends to genetically modified animal cells and animals for use in the technique. It also covers transgenic animals providing a source for the cells and selectable marker constructs for producing genetically modified cells and transgenic animals.

The Patent Office said last week that the patent could not cover embryonic stem cells - although it could cover all other stem cells. Biotechnology industry legal sources told BioWorld International last week that the decision amounted to a very broad interpretation of the European Union rules on biotechnology patents. The EU rules prohibit patenting the "commercial uses of the human embryo" - but the Patent Office ruling would go further, excluding not only human embryos from patentability, but also human embryonic cells.

Industry sources pointed out that the Patent Office appears to have ignored the findings of the EU's advisory group on ethics, which recently stated that patents covering genetically modified human stem cells could be acceptable.