Broad Functional Biotech Claims in the BGH and EPO

Kluwer Patent Blog has a very interesting post by Dr Thorsten Bausch et al on a split between the German Federal Court of Justice (Bundesgerichtshof) and the EPO on the validity of broad functional claims. As the post describes it:

one can paraphrase [the claim at issue] as "the use of DP IV inhibitors for the preparation of a medicament for treating diabetes". The claimed inhibitors were not structurally limited, just by their function. The description of the patent contained a single working example with data. However, as the claims were so broad and Prof. Demuth's concept proved to be unusually successful, it happened, unsurprisingly, that both patents were opposed by various major pharmaceutical companies. Indeed, the patents were arguably covering a whole new class of anti-diabetes drugs under development, which today are collectively referred to as gliptins. Marketed actives of this class include Sitagliptin, Vildagliptin and Saxagliptin.

The EP patent was revoked by the EPO BoA, but the equivalent German patent was subsequently upheld by the BGH, which explicitly disagreed with the BoA decision. The authors provide an English translation of BGH decision, which cites extensively from German, UK and EPO case law. The BGH held, inter alia, that

The fact that such a claim also covers compounds which do not yet exist, or which have not yet been identified, does not give grounds for concern. If employing them makes use of the invention, it does not matter if compounds are also covered which cannot be identified without inventive activity.

There is no conflict between this and the fact that a functional definition of the feature encompasses the use of currently unknown possibilities which might only be provided or invented in the future, if this is the only way to ensure appropriate protection In such a case, the invention is in principle sufficiently disclosed if it provides the skilled person with at least one way of carrying it out.