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Inventive step clarified by the High Court of Australia - 4 September 2015
An inventive step is the Australian equivalent of the US's non-obviousness requirement. Our most authoritative Court, the High Court of Australia, has recently considered the issue in AstraZeneca AB v Apotex Pty Ltd  HCA 30.
Pleasingly, oft-cited earlier authority as to the core inventive step test is affirmed (thus providing consistency in our law) and previously unanswered questions regarding other aspects of the test have been addressed.
The invention and the decision
In Australian patent no. 200023051, AstraZeneca claimed the daily oral administration of 5 to 10 mg of a particular anti-cholesterol drug, rosuvastatin, against a background of:
- a citation disclosing rosuvastatin and that dosages 'are usually 0.5‑200 mg/day, preferably 1‑100 mg/day for oral administration';
- another citation that disclosed another promising anti-cholesterol drug, NK-104; and
- a standard practice of treating patients with similar drugs (statins) by initially administering a low dose, then increasing that dose as necessary and as any adverse side effects permit.
The Court held that the invention lacked the inventive step necessary to sustain an Australian standard patent.
The inventive step test
Under Australian law, an invention is taken to involve an inventive step unless it would have been obvious to a person skilled in the relevant art. Over time, this core aspect of the test has remained unchanged, although the prior art information to be taken into account when applying the test has changed:
- Under the Patents Act 1952, the relevant information consisted of the skilled person's common general knowledge.
- The introduction of the Patents Act 1990 expanded the relevant information by allowing the addition of a single piece of prior art information that the skilled person could 'be reasonably expected to have ascertained, understood and regarded as relevant to work in the relevant art in the patent area'.
- In relation to patent applications filed after 1 April 2002 (and patents granted thereon), it is also permissible to have regard to any two or more pieces of prior art information that the skilled person could be reasonably expected to have combined.
- In relation to patent applications the examination of which was requested on or after 15 April 2013, a single piece of prior art information could be relied upon regardless of whether the skilled person could 'be reasonably expected to have ascertained, understood and regarded as relevant to work in the relevant art in the patent area'.
The core inventive step test
The meaning of the word 'obvious' is central to the inventive step enquiry. The High Court traced the origins of the Australian inventive step requirement and affirmed what has elsewhere been referred to as the 'modified Cripps question':
'Would the notional research group at the relevant date, in all the circumstances, which include a knowledge of all the relevant prior art and of the facts of the nature and success of [the existing compound], directly be led as a matter of course to try [the claimed inventive step] in the expectation that it might well produce a useful alternative to or better drug than [the existing compound]?'
Accordingly, the High Court found no error in the lower Court's reasoning in which 'His Honour posed the question thus:
"whether the notional skilled person would have directly been led as a matter of course to try the invention as claimed in the expectation that it might well produce a better method of treating a patient suffering from hypercholesterolemia than existing statins and doses."'
No invention in the selection between citations
The patent was granted on an application filed 1 February 2000, hence the relevant art corresponds to category B (above). Relevantly, one of the citable documents pointed towards rosuvastatin whilst another pointed towards another option, NK-104. Much of the Court's analysis is also informative in respect of categories C and D.
'AstraZeneca's contention seemed to be that a person skilled in the art, confronted by a choice between rosuvastatin and NK‑104, would not be able to identify the pathway to a solution of the problem.'
This contention was rejected both in terms of its underlying factual assumption (i.e. that the skilled person would not be able to identify a pathway was not borne out by the evidence) and in terms of the law applicable to those facts:
'The question is not whether it would have been obvious to the skilled addressee to choose rosuvastatin over NK‑104; rather, it is whether a person skilled in the art would, in light of the common general knowledge plus either the Watanabe article or the 471 patent, have been directly led as a matter of course to try rosuvastatin in the expectation that it might well produce a solution to the problem which existed in the common general knowledge. Section 7(2) does not contemplate that a choice between apparently effective solutions must be attributed to the notional skilled addressee, much less that the notional skilled addressee might be so befuddled by an embarrassment of choices as to cease pursuit of the solution.'
Mechanical Engineer & Patent Attorney
 "(a) prior art information made publicly available in a single document or through doing a single act; and
(b) prior art information made publicly available in 2 or more related documents, or through doing 2 or more related acts, if the relationship between the documents or acts is such that a person skilled in the relevant art in the patent area would treat them as a single source of that information"