8.7.5.7 Reach-Through Claims

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  • Claims to Reach-Through Compounds per se
  • Claims to the Use of Reach-Through Compounds

‘Reach-through’ claims define compounds in terms of specified properties identified in a screening method or assay.  This style of claim is more prevalent in the chemical and biochemical areas.

Claims to Reach-Through Compounds

Each specification should be assessed on its own merits, based on a proper construction of the specification and the facts of the case.  In general, claims to unspecified ‘identified’ compounds per se are speculative.  Such claims encompass any compounds identified as possessing the properties being screened for, regardless of whether they have been explicitly disclosed in the specification.  

However, the ‘identified’ compound already existed prior to the testing process.  Therefore, in the majority of cases, the invention will not reside in the compound itself, but rather in the consequential uses of the compound (based on the properties identified by the screening assay).  Thus, claims to the unspecified compound per se, merely identified by the screening assay, will travel beyond the subject matter of the invention described in the specification and consequently lack fair basis.

A claimed compound per se, which is explicitly identified in the body of the specification, will be fairly based.  However, a screening assay does not produce a new compound, it identifies the properties of an existing compound.  An objection may be taken that prima facie the compounds per se lack novelty, because the screening assay does not produce a new compound, it identifies the properties of an existing compound.  Examiners are not required to undertake a search in order to locate a novelty citation (see also 2.4.12.1.10 Reach-Through Claims for further information on novelty considerations).  

Claims to the Use of Reach-Through Compounds

In some circumstances, claims to the downstream uses of functionally defined, but otherwise unspecified ‘identified’ compounds, may be fairly based.  Where the invention relates to a new principle, a claim will be fairly based, provided it is restricted to the use of the ‘identified’ (i.e. functionally defined) compounds in a novel and inventive practical application of that principle.

For example, an applicant has discovered that inhibiting the activity of protein X leads to the effective treatment of disease Y and has developed as assay to identify compounds with the inhibitory activity that can be used to treat the disease.  In this situation, a claim to all means of inhibiting protein X to treat disease Y would be fairly based, even though only a small number of compounds that inhibit protein X are disclosed.