Inventive step

It is generally understood that for an invention to be patentable it must be novel/new compared to what is known. However, to be patentable an additional hurdle exists - the invention must also involve an inventive step.

The Australian test for inventive step as described in Section 7(2) of the Patents Act 1990 is:

an invention is to be taken to involve an inventive step when compared with the prior art base unless the invention would have been obvious to a person skilled in the relevant art in the light of the common general knowledge before the priority date of the relevant claim.

The assessment of inventive step is more nebulous than the objective determination of novelty. The operative word in Section 7(2) is “obvious” and courts have indicated that this is a flexible and indeterminate standard.1 Further, the issue will often turn on the evidence of experts.2

Courts have stressed that ex post facto analysis (dissection of the invention and working backwards to reach the prior art) is not helpful in resolving the question of obviousness.3 In certain circumstances, the modified Cripps question is an aid to answering the statutory question posed by Section 7(2)4:

Would the person skilled in the art (in all the circumstances) directly be led as a matter of course to try the claimed invention in the expectation that it might well produce a solution to the problem?5

Mylan Health Pty Ltd v Sun Pharma ANZ Pty Ltd

The Mylan Health Pty Ltd v Sun Pharma ANZ Pty Ltd [2020] FCAFC 116; 279 FCR 354; 380 ALR 582; 153 IPR 199 (Mylan) decision provides an important illustration of the risks to future patent protection arising from speculative disclosures in prior art documents. Part of the decision related to whether a speculative disclosure could invalidate a patent claim by rendering the invention obvious.


Early Treatment Diabetic Retinopathy Study Report 22 suggests that lipid-lowering may decrease the risk of hard exudate formation and associated vision loss in patients with diabetic retinopathy.


Use of fenofibrate or a derivative thereof for the manufacture of a medicament for the prevention and/or treatment of retinopathy, in particular diabetic retinopathy.

It was considered that the lipid lowering potential of fenofibrate was common general knowledge and as such based on the modified Cripps question it was held that:

the notional skilled team would have been directly led by ETDRS 22 to try fenofibrate (because of its effectiveness in reducing elevated triglyceride levels and increasing HDL cholesterol levels) in combination with statins (because of their effectiveness in reducing elevated LDL cholesterol levels) in the expectation that this might well prevent or slow the development or progression of retinal hard exudates.

It was also affirmed that the expectation required by modified Cripps question is not to be analysed in percentage terms, especially not as a fifty-fifty proposition.6

Academic speculation

This modified Cripps question should be front of mind for researchers disclosing their findings in articles or oral presentations, particularly from research programs involving fundamental research and commercial product development. An inventor’s own prior disclosures can inadvertently render their later invention obvious by directly speculating that the invention might be achievable. Generic statements like the below are relatively common in an academic context:

We envisage that X (our discovery) could be combined with Y (technology from another field) and the result would be Z … and Z is beneficial because of A, B and C.

While emphasising the translational impact of the discovery, the patentability of a subsequent invention may be forfeited due to a finding of obviousness.

Researchers must also be aware that the tests for determining whether an inventive step is present are not consistent across jurisdictions. Australia has a relatively low threshold for finding an inventive step and also a relatively high threshold for combining prior art documents. In other jurisdictions, including commercially important ones such as Europe and the US, this is not the case.

In Australia, it is typical to assess obviousness by framing the problem solved by an invention with reference to the common general knowledge in the field. Thus, in most circumstances, inventive step is considered only in view of a single prior art document as it is relatively easy to formulate arguments that additional pieces of prior art do not address the same problem. Also, a combination of prior art documents is limited to those that a PSA could be reasonably expected to combine.

Conversely, in Europe, the problem solved by the invention is framed with reference to the closest prior art. It is permissible to assess inventive step based on a combination of two or more pieces of prior art, the closest prior art document and one or more other documents that are not incompatible in their teaching or in remote fields. The combination must be obvious to a skilled person seeking to solve the problem underlying the claimed invention.

In the US, “the combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results”.7 Thus, so long as the results of the combination are predictable, numerous prior art documents may be combined in the US to render an invention obvious.

Importantly, the ability to combine documents to assess inventive step varies and will depend on the jurisdiction. If there is speculation in a disclosure about future developments this may increase the likelihood that the disclosure may be combined with another document. Therefore, particularly in Europe and the US, where it is common for numerous documents to be combined when assessing inventive step, speculative disclosures may be even more detrimental than in an Australian context.

Lessons from Mylan

  • Authors, particularly chief investigators, need to have a clear project vision and keep this in mind when reviewing manuscripts and presentations.
  • An inventor’s own prior disclosure can be raised against their patent application as prior art.
  • Do not create a path from one aspect of a research project and another (either being run concurrent or in a later phase).
  • Consider whether the benefits of speculative statements outweigh the potential ramifications in relation to intellectual property rights.

Inventors should be wary of leaving signposts pointing from their preliminary research towards a future commercially viable invention. If this warning is not heeded and others can claim to have been directly shown the path to an invention, that invention may not be patentable.



Aktiebolaget Hässle v Alphapharm Pty Ltd [2002] HCA 59; 212 CLR 411 at [90] per McHugh J


Lockwood Security Products Pty Ltd v Doric Products Pty Ltd (No 2) [2007] HCA 21; 235 CLR 173 at 52


Meyers Taylor Pty Ltd v Vicarr Industries Ltd (1977) 137 CLR 228 36 at page 242


Generic Health Pty Ltd v Bayer Pharma Aktiengesellschaft [2014] FCAFC 73; 222 FCR 336 at [71]


Aktiebolaget Hassle v Alphapharm Pty Ltd [2002] HCA 59 at 53; (2002) 212 CLR 411


Mylan Health Pty Ltd v Sun Pharma ANZ Pty Ltd [2020] FCAFC 116 at 148


KSR International Co. v. Teleflex Inc, 550 U.S. 398, 407, 415 (2007)