The patenting of stem cells is a contentious area as exciting new medical possibilities clash with ethical considerations. There has been a recent change in European Patent Office (EPO) practice which has not been officially announced but which will benefit European patent applications relating to human embryonic stem cells (hESCs) with a filing date of 5 June 2003 or later.

The patentability of biotechnological inventions in the European Union (EU) is governed by the European Directive 98/44/EC on the legal protection of biotechnological inventions (“the Biotech Directive”) which states that inventions are not patentable if their commercial exploitation would be contrary to morality.  It specifically prohibits the use of human embryos for commercial or industrial purposes.  The EPO has implemented the Biotech Directive via Article 53 and Rule 28 of the European Patent Convention.

The Court of Justice of the European Union (CJEU) has been asked to consider what the term ‘human embryo’ encompasses or what acts constitute the ‘use of a human embryo’.  In 2011, the CJEU held in case C34/10 that it is immaterial how far removed the destruction of a human embryo is from the invention.  If such destruction was in any way involved in the generation of the hESC, the invention falls foul of the morality requirement of the Directive.  Following this decision, the EPO began to consider inventions excluded from patentability if they not only directly involved the destruction of an embryo, but also if they required the use of an hESC that was originally derived through the destruction of an embryo.

In its original decision on the term “human embryo”, the CJEU held that the term encompasses the blastocyst stage (from which hESCs are typically retrieved) and any other cell capable of commencing the process of development of a human being, including the products of SCNT or parthenogenesis (‘parthenotes’).

There was a challenge to the suggestion that a parthenote constitutes a human embryo in the CJEU case C364/13 and it was felt that the CJEU may have been technically inaccurate in its presentation of parthenogenesis.  In response to this challenge, the CJEU confirmed that it was satisfied that, according to current scientific knowledge, mammalian parthenotes can never develop to term.  In December 2014 the CJEU ruled that parthenotes do not constitute a ‘human embryo’, with the proviso: “if, in the light of current scientific knowledge, [the parthenote] does not, in itself, have the inherent capacity of developing into a human being, this being a matter for the national court to determine”. The proviso was added because the court considered that it may in future become possible to genetically-manipulate parthenotes to give them the capacity to develop into a human being.

As a result of this second decision from the CJEU, the EPO once again changed its practice and allowed applications which use stem cells that, at the time the application was filed, did not require the destruction of a human embryo.

Initially, the EPO was of the opinion that the first ever report of a non-destructive method of isolating hESCs published in February 2008.  Consequently, applications involving hESCs were excluded from patentability if the filing date was before February 2008.

However, the EPO is now of the opinion that methods of deriving hESCs from parthenotes were disclosed in WO 2003/046141, which was published on 5 June 2003.  Based on the teaching provided in WO 2003/046141, the EPO considers that the skilled person would have been able to generate parthenotes and derive hESCs from them from the publication date of that application.  Therefore, the EPO now appears to consider that applications relating to hESCs that were filed after 5 June 2003 do not contravene the morality provisions of the European Patent Convention.

This change in EPO practice is clearly good news for applicants with applications relating to hESCs filed after 5 June 2003 that are still pending.  Applicants whose applications were recently refused as being contrary to the morality provisions of the EPC should consider whether there is still an opportunity to appeal against such refusal in view of this recent practice change.

This situation also suggests that future changes in practice may be seen and so applicants should also consider keeping applications pending for as long as possible.

For more information, please do not hesitate to contact any of our attorneys from the Chemical and Life Sciences team at Venner Shipley.