25 November 2008: Decision of the Enlarged Board on the Patentability of the WARF/Thomson Stem Cell Application: A method which necessarily involves the destruction of a human embryo is excluded from patentability, even if this step is not part of the claims


1.: The Referral:

The Enlarged Board of Appeal (EBA) of the European Patent Office (EPO) issued the long awaited decision in the WARF/Thomson Stem Cell Application. The patent application was initially rejected by the Examining Division. The responsible Technical Board of Appeals referred several questions to the EBA for clarifying questions with regard to patentability of inventions which involve human embryos and stem cells.

The main claim 1 of the application read:
“1 A cell culture comprising primate embryonic stem cells which
(i) are capable of proliferation in vitro culture for over one year,
(ii) maintain a karyotype in which all chromosomes normally characteristic of the primate species are present and are not noticeably altered through culture for over one year,
(iii) maintain the potential to differentiate to derivatives of endoderm, mesoderm, and ectoderm tissues throughout the culture, and
(iv) are prevented from differentiating when cultured on a fibroblast feeder layer.”

The cell culture of the invention was obtained from human embryos as starting material. For obtaining the cells, the embryo has to be destroyed. This step was described in the application as originally filed as being indispensable. The patent was filed on 19 January 1996. Rule 23d(c) (now: Rule 28(c) of the Implementing Regulation (“Under Article 53(a), European patents shall not be granted in respect of biotechnological inventions which, in particular, concern the following: [..] (c) uses of human embryos for industrial or commercial purposes;”)) was introduced and entered into force on 1 September 1999.

The Technical Board of Appeals put the following questions before the EBA:

  1. Does Rule 23d(c) (now: Rule 28(c)) EPC apply to an application filed before the entry into force of the rule?
  2. If the answer to question 1 is yes, does Rule 23d(c) (now: Rule 28(c)) EPC forbid the patenting of claims directed to products (here: human embryonic stem cell cultures) which – as described in the application – at the filing date could be prepared exclusively by a method which necessarily involved the destruction of the human embryos from which the said products are derived, if the said method is not part of the claims?
  3. If the answer to question 1 or 2 is no, does Article 53(a) EPC forbid patenting such claims?
  4. In the context of questions 2 and 3, is it of relevance that after the filing date the same products could be obtained without having to recur to a method necessarily involving the destruction of human embryos (here: eg derivation from available human embryonic cell lines)?

Rule 28 (c) was introduced to implement the wording of Article 6(2) (c) of the Directive 98/44/EC of 6 July 1998 on the legal protection of biotechnological inventions (“the Directive”). Since this stipulation must therefore – at least in the EU Member States – finally interpreted by the European Court of Justice (ECJ), the applicant also requested that the EBA referred questions concerning interpretation of this clause to the ECJ (under Article 234 EC-Treaty).

2.: The decision G 2/06:

2.1.: Referral to the ECJ:

The EBA concluded that it has no power to ask the ECJ for a preliminary ruling under the existing provisions of the EPC. “Neither the EPC nor the Implementing Regulations thereto make any provision for a referral by any instance of the EPO of questions of law to the ECJ. The Boards of Appeal are a creation of the EPC, and their powers are limited to those given in the EPC”. The absence of any provision enabling such a referral makes such referral impossible. The request for referral of the questions for a preliminary ruling by the ECJ was therefore refused as inadmissible.

2.2.: Question 1:

Since Rule 28(c) of the Implementing Regulation refers to an example of an invention the commercial exploitation of which would be contrary to “ordre public” or morality, there was no change in law involved when this Rule was introduced into the Implementing Regulation. Accordingly, Rule 28 is applicable also for applications filed before 1 September 1999. Moreover, when this Rule was introduced, no transition provisions were given. The answer to question 1 was therefore clearly “yes”.

2.3.: Question 2:

With respect to question 2, the EBA made clear that the fact that the invention necessarily involves the destruction of a human embryo made the invention unpatentable, regardless whether the step of destruction was part of the claim or not. The EBA stated: “the legislators [..] wanted to exclude inventions such as the one underlying this referral from patentability” and that any narrower approach (by looking at the claimed language only) “would have the undesirable consequence of making avoidance of the patenting prohibition merely a matter of clever and skilful drafting of such claim”. The answer to question 2 was therefore also “yes”.

2.4.: Question 3:

In view of the answer to questions 1 and 2, question 3 was obsolete.

2.5.: Question 4:

Finally, for question 4, the EBA made also clear that technical developments which become publicly available only after the filing date cannot be taken into consideration. “Similarly to the case of an invention which is insufficiently described in the application as filed to be carried out, lack of any disclosure in the application as filed putting the skilled person in possession of a way to carry out the invention complying with Rule 28(c) EPC cannot be cured by the occurrence of subsequent technical developments.” Accordingly, since no other way for arriving to the claimed cells was disclosed to the skilled man in the art than destroying human embryos, the method as a whole was regarded as unpatentable under Article 53 c) in connection with Rule 28(c). The answer to question 4 was therefore “no”.

Daniel Alge, 28. November 2008

01.12.2008