The amendments to the Patents Act under Raising the Bar brought changes to the enablement provisions required by Australian patent specifications. This article provides a brief review of three recent categories of “enablement” objections, and highlights the importance of carefully drafting the description to support and enable claim scope.


Under the previous version of the Patents Act, for “enablement” to be met, the specification was required to “describe the invention fully”.1 Generally, the Patent Office was of the view that this criterion was met if the disclosure enabled the skilled person to produce something within each claim without further invention.2 Notably, there was no requirement that the claims were enabled over their full scope.3

Post-raising the bar, for enablement to be met, the Patents Act now requires that the complete specification “discloses the invention in a manner which is clear enough and complete enough” for the invention to be practiced,4 and that the claims are supported5 by this disclosure.

There is presently no case law to guide the interpretation of the new “enablement” provisions. However, the patent office considers “enablement” to be met where the specification enables the invention to be performed to the full extent of the monopoly claimed.6

Markush structures

Markush structures provide a simple mechanism for claiming the core structure of a molecule while allowing for different substituents on that core structure. In this way, a Markush structure can cover many thousands (and potentially millions) of alternative compounds based on a core structure. Given the potential scope of a Markush claim and that it is not practically possible to exemplify every compound that falls within its scope, there is a balance between providing a claim that does not extend beyond the contribution the inventor has made while retaining sufficiently broad scope to prevent simple design around.

Following the changes to Australian patent law, it is common for the Patent Office to object that a broad Markush claim is not enabled across its full scope on the basis that the specification does not provide sufficient guidance to produce each and every compound covered by the claim. This is often as a result of the specification providing only a handful of exemplified compounds with highly specific methods for forming those compounds.

The objections can be argued. The strength of any arguments which can be put forward by the Applicant is often highly dependent on the disclosure of the specification, and the degree to which that disclosure can be generalised. Given this, particular care needs to be taken when drafting a patent specification to ensure that there is adequate support for a broad Markush claim, which may include synthetic pathways that can be generalised to cover a much wider range of compounds than those explicitly disclosed.

Alloy compositions

Alloy claims are generally subject to strict patentability criteria. However, recently the patent office has placed greater emphasis on the examples and raised enablement objections where the claims omit constituents which are common to the examples regardless of whether those constituents are disclosed as being optional in the body of the specification.

This issue can arise as the examples are often in respect of preferred commercial forms of the alloy which include an amount of an optional alloying element (for providing some supplementary effect). There is a risk that the patent office will consider the disclosure to provide enablement only for an alloy that includes these “optional” alloying elements. As with all objections, potentially this can be successfully argued, but again the strength of such arguments is subject to the actual disclosure of the specification.

Ideally the specification includes an example of the alloy in its broadest possible form. However, this is not always practical, particularly if the composition defined in the claims has changed during prosecution. As such, care needs to be taken when drafting the description of alloy compositions to ensure that there is a clear delineation between what constituents contribute to the underlying mechanism essential for providing a desired alloy and optional constituents which may be included to confer additional advantages.

Synergy and synergistic compositions

Synergistic compositions are those that exhibit an effect that is greater than the combined effect of each of the constituents when considered alone.

It is common for the patent office to object that broad claims to a “synergistic composition” per se lack enablement. The patent office provides a number of standard arguments in support of such an objection (subject to the particular claim in question) including: (i) it is unclear how synergy is determined, (ii) synergy has not been demonstrated across the full scope of the claim, (iii) there is an undue burden placed on the skilled person to work out the constituents and relative concentrations thereof to achieve synergy, (iv) synergy has only been demonstrated for a particular application.

Each of these issues should be considered carefully when drafting the patent specification. Ideally the specification should provide some indication of how synergy is determined. Experimental data is essential for validating synergy and for generalising the scope of protection. Of course, an examiner may argue that the “synergistic composition” should be limited to those circumstances that give rise to that synergy – which may result in a product claim that is limited by use. However, it is possible to pursue broader claims, particularly if the experimental results identify an underlying mechanism that gives rise to the synergistic effect.