Broad or Speculative Claims

Date Published

Note: The information in this part only applies to:

•  standard patent applications with an examination request filed on or after 15 April 2013.
•  innovation patents with an examination request filed on or after 15 April 2013.
•  innovation patents where the Commissioner had not decided before 15 April 2013 to examine the patent.

Each application should be assessed on its own merits, based on a proper construction of the specification and the facts of the case.

An objection for lack of support should be raised where the claims are broad and speculative, in that:

  • the scope of the claims extends beyond the disclosure to encompass possibilities, the effects of which cannot readily be predetermined or assessed on the basis of what is described in the body of the specification; and
  • the description gives merely an indication of the full breadth or scope of the invention, but no, or inadequate, directions of how to put it into practice across the full width of the claims.

Where a broadly drafted claim is not enabled over its full scope, or if it encompasses matter that is broader than is justified by the contribution to the art, the claim will lack support under sec 40(3).

Some common types of broad claims are as follows:

Reach-Through Claims

Reach-through claims define compounds in terms of specified properties identified in a screening method or assay and are more prevalent in the chemical and biochemical areas.  For information on examining reach-through claims in the context of sec 40 see Reach-Through Claims.

Markush Claims

Classical Markush claims provide a convenient means for defining a large number of alternative compounds by way of a generic core structure with defined substituents (see also Markush Practice, 1.1.19 Annex AA Markush Claims and 2.11A Annex A – Examples: Subsections 40(2)(a) and 40(3)).

In order that claims defining a class of compounds in terms of a Markush structure are supported over their whole scope, the body of the specification must provide sufficient information to enable the skilled addressee to make every compound falling within the scope of the claims.  Where the activity of the compound is a feature of the claim, the class of compounds must be such that the person skilled in the art would have a reasonable expectation that all of the class members will behave in the same way, in the context of the specification.

Substituents in Chemical Structures

The scope of terms such as ‘leaving group’ and ‘protecting group’ are well understood in the chemical arts.  Such terms represent a principle of general application, where the person skilled in the art would reasonably expect the invention to work with anything that falls within the general term.  An example of one member of the group would normally provide an enabling disclosure for a claim referring to all members.  

Broader terms, such as ‘optionally substituted’ where the substituents are not defined, are unlikely to be supported over their entire scope.  An undefined substituent will encompass a diverse range of possibilities which cannot represent an underlying principle of general application.  An example of one substituent, or even several examples, cannot enable all others.  In the majority of cases, such claims will not be enabled over their full width and the scope of the claims will exceed the contribution to the art, contrary to sec 40(2)(a) and sec 40(3) .

Genetic Markers or Biochemical Markers

In the biotechnology field, claims often refer to methods for detecting (for example) physiological and pathological conditions, using two or more of any number of genetic or biochemical markers.  The claims often define a large number of potential markers and possible combinations, where only a few combinations of markers are exemplified.  In the absence of relevant examples over the whole scope of the claims and/or an indication of the response of any given marker and marker combination for a specific condition in comparison to controls, the claims are unlikely to be enabled over their full scope and will consequently lack support under sec 40(3).  If so, an objection under sec 40(2)(a) will also apply.