The Enlarged Board of Appeal of the European Patent Office has today published its decision in the long-awaited case concerning the patentability of human embryonic stem cells (hESCs). This application was filed by the Wisconsin Alumni Research Foundation (WARF) in 1995 and describes a method for obtaining embryonic stem cell cultures from primates, including humans.

The Enlarged Board addressed four questions posed by a Technical Board of Appeal relating to the patentability of the WARF application. In this preliminary article, we set out the questions and the answers given by the Enlarged Board.


Should a rule that came into force after the application apply?

The rule in question concerns the unpatentability of uses of human embryos for industrial or commercial purposes.

Enlarged Board: Yes. The rule applies to all pending applications, including those filed before the entry into force of the rule.


If so, does the rule forbid claims to products (here, hESC cultures) when the method at the filing date necessarily involved the destruction of a human embryo if that method is not claimed?

Enlarged Board: Yes. The rule forbids the patenting of claims directed to products which (as described in the application) could at the filing date be prepared exclusively by a method which necessarily involved the destruction of the human embryos from which such products are derived. It was immaterial that the method was not part of the claims.


If answers to 1 or 2 is "no" does Article 53(a) forbid patenting of such claims?

The reference is to Article 53 of the European Patent Convention, to which "the rule" described in Question 1 refers. So this question refers to claims to inventions the commercial exploitation of which would be contrary to "ordre public" or morality.

Enlarged Board: As the answers to the first two questions were both "yes" no answer is required.


Is it relevant that same products could be obtained after the filing data without having to destroy an embryo?

Enlarged Board: No.


The Enlarged Board of Appeal emphasised that its decision did not concern the patentability in general of inventions relating to human stem cells or to human stem cell cultures, summarising its position as holding "unpatentable inventions concerning products (here human stem cell cultures) which can only be obtained by the use involving their [sic] destruction of human embryos".

Plainly, all stem cells are not embryonic. However, many are indirectly derived from embryos; for example progenitor cells which have been derived from plated hESCs. Are they and the methods for their derivation barred from patentability? Reading the answer to Question 2, the answer appears to be "no", because such cells are not "products which could …be prepared exclusively by a method which necessarily involve(s) the destruction of the human embryos from which such products are derived": they come from cell lines, not embryos.