Perspective

Inventive Step Test Clarified in AstraZeneca AB v Apotex Pty Ltd [2015] HCA 30

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In AstraZeneca AB v Apotex Pty Ltd & Ors [2015] HCA 30 the High Court of Australia upheld the decision of the Full Federal Court in relation to the appropriate “starting point” for consideration of inventive step or obviousness of an invention.  The decision relates to AstraZeneca’s patents relating to low dosages of the cholesterol lowering drug rosuvastatin.

Subsections 7(2) and 7(3) of the Patents Act 1990 (Cth) were considered in each of the trials at first and second instance before the Federal Court and before the High Court. These subsections provide that an invention does not involve an inventive step if it would have been obvious to a person skilled in the art in light of the following before the priority date of the patent: (a) the common general knowledge considered alone; or (b) the common general knowledge considered together with prior art information publicly available in a single document.

A further requirement of the 1990 Act, since altered by the Raising the Bar legislation which came into force in 2013, is that the single document is to contain prior art information which could reasonably be expected to have been “ascertained, understood and regarded as relevant” by the person skilled in the relevant art.

There was no dispute between the parties that rosuvastatin did not form part of the common general knowledge attributable to the person skilled in the art at the time the invention was created. The existence of rosuvastatin was disclosed in two prior art documents, one of which was a European patent which claimed the invention of the compound rosuvastatin and methods of preparing it, and the other was a journal article referred to during the trial as the Watanabe article. The judge at first instance and the Full Federal Court on appeal considered that the invention lacked an inventive step by reference to the common general knowledge considered with either of the two prior publications.

The decision at first instance:

The judge at first instance in Apotex Pty Ltd v AstraZeneca AB (No 4) [2013] FCA 162, in assessing inventive step (or obviousness) of the claimed invention in one of the patents in suit, treated rosuvastatin (the active ingredient) as a “given” because it was disclosed as such in the specification.  In other words, the judge concluded that the invention, as disclosed in the specificiation, presupposed the existence of rosuvastatin. In coming to this conclusion the primary judge rejected the patentee’s arguments that the existence of rosuvastatin should did not be taken to be a given when determining the starting point for assessing inventive step as to do so would be akin to deeming it to form part of the common general knowledge of the person skilled in the art.

The judge relied, at least in part, upon an earlier Full Federal Court decision in Apotex Pty Ltd v Sanofi-Aventis [2009] FCAFC 134 in which a similar situation had arisen in which the patent specification claimed one structural form of a compound (PCR 4099) which existed as a ‘racemic mixture’ of two structural forms. Although PCR 4099 did not form part of the common general knowledge at the relevant date, the court found that due to the way that the invention was described in the specification the racemic mixture was the starting point for determining inventive step. As such, the inventive step was the separation of PCR4099 from the racemic mixture as that structural form of the compound had the desired activity. The court went on to conclude that separation of the active structural form of the compound was obviously desirable and could be achieved without great difficulty and, as such, could not impart the requisite inventive step.

Whether the first instance judge’s approach to determining what has become known as the “starting point” for assessing inventive step (or obviousness) was correct was considered on appeal by an expanded Full Court panel of five judges in AstraZeneca AB v Apotex Pty Ltd [2014] FCAFC 99 (12 August 2014).

On appeal at second instance:

AstraZeneca argued before the Full Court that the first instance judge’s approach was incorrect and that the Full Federal Court in Apotex Pty Ltd v Sanofi-Aventis was either wrong or not relevant as it related to inventive step under the previous Patents Act 1952 and, in any event, could be distinguished on the facts of the case.

The full court noted that the patent specification in suit included disclosure that could reasonably lead to a definition of the problem that the invention sought to overcome in three different forms:

Is it possible to devise a new method for the treatment of hypercholesterolemia?
Is it possible to devise a new method for the treatment of hypercholesterolemia using a statin?
Is it possible to devise a new method for the treatment of hypercholesterolemia using rosuvastatin?

The first instance judge had considered the inventiveness of the invention by asking the question in the third form. By taking as a given the existence of rosuvastatin the judge concluded that the ‘starting point’ for devising the claimed dosage regime was the use of rosuvastatin. Thus the development of an effective dosage regime was a matter of routine and, hence, the invention lacked the requisite inventive step.

The appropriate “starting point” for assessing obviousness/inventive step

The full court stated, in relation to the appropriate “starting point” for assessing inventive step, that:

“if the problem addressed by a patent specification is itself common general knowledge, or if knowledge of the problem is section 7(3) (i.e. publicly available) information, then such knowledge or information will be attributed to the hypothetical person skilled in the art for the purpose of assessing obviousness. But if the problem cannot be attributed to the hypothetical person skilled in the art in either of these ways then it is not permissible to attribute a knowledge of the problem on the basis of the inventor’s “starting point” such as might be gleaned from a reading of the complete specification as a whole.”

The court went on to provide several reasons why the above conclusion regarding the “starting point” for assessing inventive step is the correct one. Firstly, the inventor’s “starting point” as disclosed in the specification might not be one that would suggest itself to the hypothetical person skilled in the art. The contents of the complete specification may have an evidentiary significance, for example, as an admission which might lead to a finding that a piece of information referred to is common general knowledge or subsection 7(3) information. But that does not mean knowledge or information that is not common general knowledge and not subsection 7(3) information can be used to supplement information used for the purposes of assessing inventive step.

A number of other reasons were provided by the full court suggesting that if the approach of the judge at first instance were followed it would lead to an outcome where inventiveness is dependent upon the way an invention is described in a specification rather than by reference to the state of the art and the common general knowledge attributable to a person skilled in the art at the time the invention was made.

The full court concluded that the “starting point” approach to obviousness adopted by the Full Court in Sanofi-Aventis (2009) in relation to subsection 100(1)(e) of the old 1952 Act is incompatible with what is essentially an objective comparison that must be undertaken under the new 1990 Act between the invention as claimed and the relevant prior art (i.e. the common general knowledge and any available subsection 7(3) information) and should not be followed in situations where the provisions of the 1952 Act do not apply.

Nevertheless, the Full Court did not disturb the decision of the judge at first instance that the patents were invalid as the claimed inventions lacked novelty or lacked an inventive step in light of the common general knowledge and the prior art information contained in either the European patent or the Watanabe article.

On appeal before the High Court:

On appeal, the High Court of Australia in AstraZeneca AB v Apotex Pty Ltd & Ors [2015] HCA 30 did not comment upon the Full Federal Court’s formulation of the “starting point” for assessing inventive step.  Accordingly, the Full Federal Court’s formulation may be assumed to be the correct one.

Should prior art documents be considered “separately” when determining relevance?

Instead, the High Court made findings in relation to other aspects of the inventive step assessment and, in particular, determining whether prior art information contained in a document satisfies the “ascertained, understood and regarded as relevant” requirement of subsection 7(3).  AstraZeneca argued that subsection 7(2) requires that non-common general knowledge sources of information must be ‘considered separately’ both for assessing whether the invention is obvious in the light of the common general knowledge and “at the anterior step of assessing whether or not any given source of information satisfies the ‘ascertained, understood and regarded as relevant’ requirement in subsection 7(3).”  They contended that it was impermissible for the person skilled in the art to compare multiple documents that they had ascertained and to select from these the relevant document or documents to be used for answering the question of obviousness under subsection 7(2).

The High Court rejected the approach proposed by AstraZeneca. holding that there is nothing impermissible in such an exercise of selection. Gageler and Keane JJ stated:

“the plain and ordinary meaning of the language of s 7(3) imposes no limitation on the search for information outside the common general knowledge other than that the information must be “reasonably expected to have [been] ascertained, understood and regarded as relevant to work in the relevant art in the patent area.”  Nothing in subsection 7(3) suggests that the notional skilled addressee may not trawl through multiple documents, discarding the irrelevant and retaining the useful, as part of the ascertainment of relevant information.”

The requirement set out in subsection 7(2) that prior art documents must be considered separately is intended to restrict “mosaicing” of prior art references when assessing inventive step.  That is where multiple pieces of prior art information are combined together into a mosaic of information that leads the person skilled in the art to the claimed invention.  However, AstraZeneca had sought to rely on the requirement that documents must be considered separately to call into question whether a single piece of prior art could be considered to have been “ascertained, understood and regarded as relevant” if it was selected by a person skilled in the art as being “relevant” as a result of a review of multiple documents.

AstraZeneca also sought to argue before the High Court that each document that a person skilled in the art considers to be “relevant” must be considered under subsection 7(2) and that none may be discarded. In the present case, prior art disclosing two candidate pharmaceutical compounds having the requisite effectiveness, rosuvastatin and NK‑104, could have been considered relevant by the person skilled in the art. Thus, the parties disputing the validity of the patent must prove that a person skilled in the art would have considered it obvious to choose rosuvastatin over NK‑104.  Gageler and Keane JJ stated:

“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.”

Another interesting argument raised by AstraZeneca was that the need for human testing and clinical trials for pharmaceutical inventions means that there must be a sufficient motivation in the prior art, perhaps more so than in other areas of technology, to suggest that a claim to a particular pharmaceutical invention is obvious and therefore lacking an inventive step.  The High Court rejected this argument. Gageler and Keane JJ stated:

“Section 7(2) does not invite a consideration of the notional addressee’s motivation to carry out any tests that would need to be done.  In particular, it does not contemplate consideration of whether the skilled addressee would be sufficiently encouraged by the available information to undertake the expense and inconvenience of further tests necessary to bring the solution to the stage of implementation.”

The decision of the High Court means that AstraZeneca’s defence of its rosuvastatin drug Crestor has finally ended in defeat.  An interlocutory injunction that has been in place since 2011 has now been lifted and the generic parties may now make a claim against AstraZeneca for losses by resulting from their inability to market their generic products since 2011.

 

"...Nothing in subsection 7(3) suggests that the notional skilled addressee may not trawl through multiple documents, discarding the irrelevant and retaining the useful, as part of the ascertainment of relevant information..."