Chepko Danil Vitalevich /
7 July 2014BiotechnologyJoachim Wachenfeld

Patenting stem cells: filing date is the key

In the inaugural issue of the LSIPR quarterly, Andy Sanderson analysed options of obtaining patent protection in the aftermath of the Brüstledecision of the Court of Justice of the European Union (CJEU) that further restricted options of applicants to obtain patent protection for human embryonic stem (hES) cell-related inventions.

The CJEU made clear that, at least for inventions claiming priority prior to 2008, hES cells cannot be patented even where the cells are derived from an established hES cell line rather than directly obtained from an embryo. The reasoning behind the CJEU’s decision was that the technology prior to 2008 allowed hES cell lines to be established only by destruction of an embryo.

Prior to the issuance of the Brüstle decision by the CJEU, the Enlarged Board of Appeal (EBA) of the European Patent Office (EPO) in its decision G2/06 had ruled on the patentability of stem cell-related inventions. It held that inventions pertaining to hES cells constituted unpatentable subject matter if the application only disclosed ways of obtaining hES cells comprising the destruction of an embryo.

Significantly, the EBA stated that its decision was “not concerned with the patentability in general of inventions relating to human stem cells or human stem cell cultures”. Thus, it was then left open whether hES cell-related inventions making use of established hES cells could constitute patentable subject matter.

In practice, the EPO generally accepts applications relating to hES cells with an effective date after 2008. This parallels the CJEU decision, finding that after 2008 methods became available to obtain hES cells without the need to destroy human embryos. But this does not provide any reprieve to applicants whose applications only enjoy an effective filing date prior to 2008. At the time, one of Sanderson’s suggestions to applicants was to argue that prior to 2008 and maybe even in 1997, non destructive methods for retrieving hES cells were available.

Further light

A Technical Board of Appeal of the EPO has issued a decision (T2221/10) that sheds some additional light on the patentability of hES cells. The appeal had been filed in 2010, ie, prior to the decision of the CJEU. The key question underlying the appeal was to elucidate when hES cell lines had become publicly available. The applicant sought to demonstrate that hES cell lines were publicly available as of 1998, ie, the first publication of hES cell lines by Thompson and colleagues in Science (Science 282 [1998], 1145-1147).

Since the EBA had in G2/06 not finally decided on the patentability of hES cells, it is interesting to see how the board interpreted this decision in view of the Brüstle case.

"Applicants should carefully consider any investment of additional funds into the prosecution of such applications before the EPO."

As regards the public availability of hES cell lines, the board found that the evidence presented by the applicant was insufficient for demonstrating that those cell lines were indeed publicly available in 1998. Inter alia, the board was not persuaded by the general statement in the 1998 Information for Contributors of Science that any materials and methods necessary to verify the conclusions of the experiments reported must be made available to other investigators under appropriate conditions.

They were also unconvinced by the similar requirement for publication in the journal Developmental Biology, which had also published a paper disclosing hES cell lines and was cited by the applicant in these proceedings. The board also expressed doubts that an institution called into life by the Wisconsin Alumni Research Foundation (WARF) in 2000 for the distribution of hES cell lines to qualified scientists would indeed distribute such cells in 2000, given the close relationship of WARF with the exclusive licensee of the WARF patent, Geron Corp, and the commercial interests of the latter.

These doubts were not alleviated by the fact that Geron and WARF had signed a document agreeing in 2002 to grant research rights to hES cell lines to academic researchers without royalties or fees. Nor was the board convinced by the applicant’s reliance on decision T128/92 where a Technical Board had acknowledged public availability of certain cell lines obtainable by various institutions despite the fact that none of the institutions was apparently “under any duty to maintain these cell lines and make them available to the public”.

Equally interesting is the board’s interpretation of G2/06 per se. Faced with the Brüstle decision of the CJEU, a strong trend for harmonising the case law of the EPO with the case law of the CJEU transpires from T2221/10. Although the EBA in G2/06 concluded that it was not authorised to find a ruling of the CJEU as precedential by, for example, the interpretation of Article 6(2)(c) of the Biotechnology Directive (98/44/EC) corresponding to Rule 28(c) of the European Patent Convention (EPC), the board in T2221/10 nevertheless found that the judgments of the CJEU “should be considered as being persuasive”.

It justified this position merely by the need for harmonisation in European patent law, a position that had already been taken by the EPO (eg, OJ EPO 1999, page 573) as well as by its EBA in G5/83 (Reasons for the decision, Section 6).

Another important issue that can be taken from T2221/10 is the board’s interpretation of how far-reaching the EBA in G2/06 construed the exclusion principle of Rule 28(c) EPC. Whereas readers might have understood the ruling of the EBA as limited to applications in which the only option disclosed for obtaining hES cells was the destruction of human embryos, the board in T2221/10 applied a wider perspective of the exclusion principle.

In Section 23 of the Reasons of G2/06, the EBA stated that “in a case like the present one, where the teaching to obtain the embryonic human stem cells is confined to the use (involving their destruction) of human embryos”, the appellant’s argument could not be accepted that considering all steps preceding the claimed invention was too far-reaching interpretation of Rule 28(c).

In the board’s reading, this statement from the EBA means that “publicly available hES cell lines (note: even in the case of public availability which was denied for the actual case) which were initially derived from a process resulting from the destruction of human embryos are excluded from patentability”. Thus, any potential gap between the ruling of the EBA in G2/06 and the CJEU in the Brüstle case has been closed by the board in T2221/10.

In summary, the chances of obtaining patent protection for hES cell-related inventions having an effective filing date before 2008 are further diminished by decision T2221/10.

Applicants should carefully consider any investment of additional funds into the prosecution of such applications before the EPO. On the other hand, hES cell-related applications enjoying an effective filing date as of 2008, if properly written, will not be negatively affected by this decision.

Joachim Wachenfeld is a partner at Vossius & Partner. He can be contacted at

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