In AstraZeneca AB v Apotex Pty Ltd; v Watson Pharma Pty Ltd; v Ascent Pharma Pty Ltd  HCA 30, the High Court of Australia (High Court) unanimously upheld the decision of an expanded bench of five judges of the Full Federal Court, and a previous decision of a single judge of the Federal Court, that the invention claimed in AstraZeneca’s Australian Patent No. AU200023051 (the ‘051 Patent) relating to an orally administered, low dosage form of the drug rosuvastatin (marketed by AstraZeneca as Crestor®), lacked an inventive step (was obvious), and that the relevant claims were therefore invalid.
KEY OUTCOMES OF THE HIGH COURT DECISION
- In determining whether a person skilled in the art would regard prior art information to be relevant for the purposes of determining whether an invention involves an inventive step, regard may be had to one or more sources of prior art information, irrespective of whether such information forms part of the common general knowledge (CGK).
- Each source of prior art information must be considered separately in light of the CGK. Any single source of prior art information that teaches the claimed invention will invalidate that claim for lack of inventive step, irrespective of whether other sources of prior art information exist that suggest different solutions to the problem.
- Conducting clinical trials is considered routine where there is a requirement to provide safety data and the mere absence from a source of prior art information of information that could reasonably be obtained from conducting such trials will not preclude a finding of lack of inventive step over that source of prior art information.
- Under the Patents Act 1990 (cth) (the Act), inventive step is to be assessed by reference to the CGK and prior art information, and that information is not to be enlarged by reference to the description of the invention (including the problem said to be solved by the invention) in the body of the patent specification (although that information may be taken into account if it is part of the CGK or prior art information). In other words, the description of the invention (including the problem said to be solved by the invention) in the body of the patent specification, which is not part of the CGK or part of the prior art information, is not to be taken as the “starting point” for assessing inventive step. This was the holding of the expanded Full Federal court, which the high court did not disturb.
The ‘051 Patent was found to be invalid by the primary judge for want of novelty, inventiveness and lack of entitlement. AstraZeneca appealed these findings to the Full Federal court, which overturned the decision in relation to novelty and upheld the other grounds of invalidity. AstraZeneca was subsequently granted special leave to appeal the Full court’s findings in relation to inventiveness and entitlement.
ASSESSMENT OF INVENTIVE STEP
Section 18 of the Act requires an invention to involve an “inventive step” when compared with the ‘prior art base’ in order to be patentable in Australia.
The test for determining whether an invention involves an inventive step is set out in section 7(2) of the Act. Section 7(2) provides that an invention is taken to involve an inventive step unless it would have been obvious to a hypothetical person skilled in the relevant art in light of the CGK before the priority date of any given claim, considered separately or together with either of the sources of information specified in section 7(3), each of which need to be considered separately. As it applied to the ‘051 Patent, section 7(3) specified prior art information publicly available in a single document (or through the doing of a single act) or two or more related documents (or acts) that the skilled person would treat as a single source of information, which the skilled person could be “reasonably expected to have ascertained, understood and regarded as relevant.”1
RELEVANT PRIOR ART
AstraZeneca argued that in determining whether a hypothetical skilled person would be “reasonably expected to have ascertained, understood and regarded (a particular document) as relevant”, the skilled person may use only information that forms part of the CGK, and not information from documents that are not part of the CGK.
The high court rejected this argument, noting that while section 7 of the Act precluded a skilled person from combining information in individual prior publications when assessing whether an invention is obvious, the skilled person may sort through “all manner of information with a view to finding something that is ‘regarded as relevant’. There is nothing in the provision which would place an embargo upon the skilled person using combinations of sources of information along the road to that destination.”2
PRIOR ART WHICH SUGGESTS “FALSE ROUTES”
AstraZeneca argued that where several prior art documents suggest alternate “routes” to solving the problem that the invention seeks to address, an invention should not be found to lack an inventive step on the basis that the “only course” available to the skilled person was one based on CGK and one relevant prior art document, as this ignores “false routes” suggested by other relevant prior art documents. It was argued that such an approach impermissibly provides the skilled addressee with the benefit of hindsight.
The high court rejected this argument on the basis that the wording of section 7(2) does not support such a construction and that, once identified, a relevant source of prior art information must be considered in light of the CGK on its own in assessing whether a claimed invention lacks inventive step, even if numerous other sources of prior art information exist that are likely to lead a skilled addressee to different solutions.
“STARTING POINT” ISSUE
In affirming the Full court’s finding of lack of inventive step, the high court found it unnecessary to address the Full court’s decision regarding the “starting point” for assessing inventive step. As a result, the Full court’s decision remains undisturbed that when assessing inventive step under the Act, the invention as claimed must be compared with the CGK and any prior art information, and that the description of the invention (including the identification of the problem) in the patent specification is not the “starting point” (or to be taken into account) for such an assessment (unless it forms part of the CGK or the prior art information).
In leaving this issue unaddressed, the high court did not resolve the potential tension between the Full court’s decision regarding the “starting point” under the Act and the earlier Full court decision in Apotex Pty Ltd v Sanofi-Aventis  FcAFc 134, which had reached a different decision regarding the “starting point” for assessing inventive step under the Patents Act 1952 (cth).3
THE TEST FOR INVENTIVE STEP
The high court applied the ‘cripps’ question to find that the skilled addressee would have been directly led as a matter of course to try rosuvastatin with the expectation that it might prove an effective treatment for hypercholesterolemia, and that testing the claimed dosage in conventional clinical trials would have been a routine step despite such trials being expensive.
The high court has held that when assessing inventive step, it is permissible to consider a number of relevant prior art documents separately (and each in light of the CGK), and that if the claimed invention lacks inventive step in light of any one of them (even if the other prior art documents suggest alternate routes), the claimed invention will still be invalid for obviousness. The decision also emphasises the routine role of clinical trials and does not disturb the Full court’s earlier decision in relation to the “starting point” for assessing whether an invention involves an inventive step under the Act.