Reach-through claim, also directed to future inventions
• A formulation of a claim whereby functionally defined chemical compounds are to be found by means of a new kind of research tool using a screening method set out in the description constitutes a reachthrough claim which is also directed to future inventions based on the one now being disclosed.
• The characterisation of chemical compounds in a claim in nonstructural, purely functional terms (in this case in terms of a specific capability) is therefore allowable only in those exceptional cases in which the invention cannot be defined more precisely in any other way without simultaneously unduly limiting its technical contribution to the art
Patent protection limited to actual disclosed contribution to the art
• it is both reasonable and indeed imperative to limit the claims' subject-matter to the invention actually disclosed in the application, which at least does not include the use of chemical compounds not yet structurally defined on its priority date and to be found only in the future using the new kind of research tool set out in the description.
• In the absence of any selection rule in the application in suit, the skilled person, without the possibility of having recourse to his common general knowledge, must resort to trial-and-error experimentation on arbitrarily selected chemical compounds to establish whether they possess the capability according to the claim; this represents for the skilled person an invitation to perform a research programme and thus an undue burden.