The European Patent Office (EPO)'s latest revisions to the Guidelines for Examination (in force on 20 June 2012) now reflect the Brüstle ruling of the Court of Justice (CJEU) on the patentability of stem cell inventions using human embryos

In short, a product which at the patent application's filing date could only be obtained by a method involving the destruction of human embryos cannot be patented in Europe. Even those inventions which involve stem cell lines that required the destruction of an embryo at some distant point in history are not patentable even if working the invention itself requires no such destruction (and whether or not the method is claimed). To determine whether the claimed product necessarily involved the destruction of human embryos, the EPO will look at the entire teaching of the application not just the wording of the claims. The disclosure is considered in light of the state of the art at the filing date.

These amendments to the Guidelines are not surprising given the ruling of the CJEU in Brüstle v. Greenpeace.1 The Guidelines are now consistent with the decision in relation to stem cell inventions using human embryos. The patentability of inventions using adult stem cells or human induced pluripotent stem cells (adult cells "reprogrammed" so that they can be used as a source of stem cells) remains unchanged by the new Guidelines. Furthermore, technologies that do not destroy human embryos should not be affected by the changes. There are now means for making human embryonic stem cells that do not require destruction so these changes may have a largely historical effect.

Notwithstanding technological developments, commentators are already discussing how these Guidelines will be employed in practice. In particular, what will the patentee have to do to persuade an Examiner that a non-destructive means could be used? Will data have to be provided in the patent specification itself or does it simply have to be plausible? It also remains to be seen how the national courts will treat any such patents granted by the EPO. Only time will tell.