AstraZeneca AB v Apotex Pty Ltd

AstraZeneca AB v Apotex Pty Ltd AstraZeneca AB v Watson Pharma Pty Ltd AstraZeneca AB v Ascent Pharma Pty Ltd [2015] HCA 30 2 September 2015 S54/2015, S55/2015 & S56/2015

A J L Bannon SC with C Dimitriadis SC and C J Burgess for the appellants in each matter (instructed by Ashurst Australia)

D K Catterns QC with N R Murray for the respondent in S54/2015 (instructed by Herbert Smith Freehills)

A J Ryan SC with I P Horak for the respondents in S55/2015 and S56/2015 (instructed by Minter Ellison Lawyers)

J T Gleeson SC, Solicitor-General of the Commonwealth with F T Roughley for the Commonwealth of Australia, intervening (instructed by Corrs Chambers Westgarth)

Notice: This copy of the Court's Reasons for Judgment is subject to formal revision prior to publication in the Commonwealth Law Reports.

AstraZeneca AB v Apotex Pty Ltd AstraZeneca AB v Watson Pharma Pty Ltd AstraZeneca AB v Ascent Pharma Pty Ltd

Intellectual property - Patents - Patents Act 1990 (Cth) - Inventive step - Obviousness - Patent disclosing method of treatment for hypercholesterolemia - Administration of rosuvastatin and its pharmaceutically acceptable salts at low dosage range in claims - Whether invention obvious in light of common general knowledge together with two prior art documents considered separately where another prior art document disclosed alternative compound - Whether prior art documents were ascertained, understood and regarded by person skilled in relevant art as relevant - Whether permissible to use information from other documents to determine relevance of information in prior art document - Use of prior art not within common general knowledge.

Words and phrases - "ascertained, understood and regarded as relevant", "considered separately", "inventive step", "obviousness", "person skilled in the relevant art".

FRENCH CJ. Introduction AstraZeneca AB, the first appellant, is the registered proprietor of Australian Patent Number AU200023051 ("Patent 051") entitled "Use of Cholesterol-Lowering Agent". AstraZeneca Pty Ltd, the second appellant, is the exclusive licensee of the Patent. The term "AstraZeneca" is used in these reasons to designate either or both appellants. The term "the Agent" used in the title of Patent 051 is defined in the specification as a compound called "rosuvastatin" and its pharmaceutically acceptable salts. Rosuvastatin is one of a class of compounds called statins which can reduce health threatening cholesterol levels in the human body by blocking the action of an enzyme called HMG-CoA reductase. The enzyme binds to a substrate HMG-CoA and mediates a reaction which transforms the substrate to mevalonic acid, a precursor of cholesterol. Statins interfere with that process by preferentially binding to the substrate, thus limiting the sites available for the enzyme and thereby reducing the production of cholesterol. Patent 051 is a method patent defining low dosage levels at which rosuvastatin is said to be efficacious in lowering cholesterol with less need for upward titration of doses over time and associated patient supervision and management than other statins existing at the priority date of the patent. The patent sets out three claims defining the invention:

1. A method of treating a patient suffering from hypercholesterolemia which comprises administration as a starting dose of a single, once daily, oral dose of 5 to 10 mg of the compound [rosuvastatin] or a pharmaceutically acceptable salt thereof, in the form of a pharmaceutical composition.
2. A method of treating a patient suffering from hypercholesterolemia which comprises administration of a single, once daily, oral dose of 5.2 to 10.4 mg of the calcium salt of the compound [rosuvastatin] in the form of a pharmaceutical composition.
3. A method as claimed in claim 1 or 2 wherein the patient has an LDL-C level of 160 mg/dl or greater with no chronic heart disease or peripheral vascular disease and one or no risk factors for such a disease; an LDL-C level of greater than 130 mg/dl with no chronic heart disease or peripheral vascular disease and two or more risk factors for such a disease; or an LDL-C level of greater than 100 mg/dl with clinically evident chronic heart disease or peripheral vascular disease. The priority date of Patent 051 was 6 February 1999. The Full Court of the Federal Court, in a judgment delivered on 12 August 2014, dismissed appeals by AstraZeneca against a decision of Jagot J in which her Honour revoked the patent on a number of grounds. Her Honour held that AstraZeneca was not entitled to the patent because the claimed method of treatment had been invented by employees of Shionogi & Co Ltd ("Shionogi"). She held that the invention as claimed lacked novelty and that it involved no inventive step having regard to the common general knowledge at the priority date whether considered by itself or in conjunction with either of two prior art publications extant at the priority date and not forming part of the common general knowledge. The two prior art publications were a European patent, referred to as Patent 471, which claimed the invention of the compound rosuvastatin and methods of preparing it and a technical journal article referred to as the "Watanabe Article". The Full Court held that the primary judge had erred in finding want of novelty. It also found, contrary to the primary judge, that the invention as claimed did not lack an inventive step having regard to the common general knowledge considered alone. However, it agreed with the primary judge that the invention as claimed lacked inventive step by reference to common general knowledge considered with either of the two prior art publications. The decision of the Full Court on that question involved the application of ss 7(2) and 7(3) of the Patents Act 1990 (Cth) ("the 1990 Act") as that Act stood at the priority date and when the Patent was applied for. Sections 7(2) and 7(3) are central to these appeals against the decision of the Full Court. They defined the condition on satisfaction of which an invention would not be taken to involve an inventive step. Relevantly, that condition was satisfied if the invention would have been obvious to a person skilled in the relevant art in light of the common general knowledge considered separately or together with prior art information publicly available in a single document before the priority date of the patent. The single document had to contain prior art information which could reasonably be expected to have been ascertained, understood and regarded by the skilled person, before the priority date, as relevant to work in the relevant art in the patent area. In this Court, AstraZeneca's primary argument was for a construction of ss 7(2) and 7(3) which would preclude the use, in the imputed ascertainment of the relevant single document, of other prior art information not forming part of the common general knowledge. Its second argument was that the Court could not decide the question of want of inventive step on the basis of a single avenue of approach based on common general knowledge and the relevant single document. AstraZeneca also challenged the conclusion by the Full Court that the appeals against the primary judge's finding of want of entitlement failed. An interlocutory application, seeking to amend the notices of appeal to invoke an assignment by Shionogi to AstraZeneca which post-dated the primary judgment and to invoke relieving provisions of the 1990 Act in relation to entitlement which came into force after that judgment, was dismissed. The grounds of each appeal to this Court by special leave granted on 13 March 2015 were: "The Full Court erred in upholding the finding of the primary judge that Australian Patent 200023051 (the 051 Patent) was invalid on the ground that the claimed invention was obvious in the light of the common general knowledge (the CGK) considered together with each of the documents referred to as Watanabe and the 471 Patent under the provisions of s 7(2) and (3) of the Patents Act 1990 (Cth) (the Act). ... The Full Court erred in upholding the finding of the primary judge that the 051 Patent was invalid on the ground that the first appellant was not entitled to the 051 Patent and in refusing to grant leave to the appellants to amend their notices of appeal and adduce further evidence directed to that issue." The first ground depended primarily upon constructions of ss 7(2) and 7(3) which their text will not bear. On their correct construction and application, the invention as claimed lacked an inventive step having regard to the common general knowledge and each of the Watanabe Article and Patent 471 considered separately with the common general knowledge. The failure of the first ground of appeal is sufficient to dispose of the appeals, which should be dismissed. Neither the second ground of appeal nor issues raised on the notices of contention filed by the respondents need to be determined. Before turning to the factual findings and evidence relating to the first ground, it is necessary to consider the construction and application of ss 7(2) and 7(3). The inventive step requirement Patent 051, being the subject of Letters Patent granted under s 61 of the 1990 Act, is a standard patent as defined in the Dictionary set out in Sched 1 to the Act. As a standard patent, it had to meet the requirement of s 18(1)(b)(ii) of the 1990 Act that "[the] invention ... so far as claimed in any claim ... when compared with the prior art base as it existed before the priority date of that claim ... involves an inventive step". The relevant part of the definition of "prior art base" set out in the Dictionary provided: "(a) in relation to deciding whether an invention does or does not involve an inventive step: (i) information in a document, being a document publicly available anywhere in the patent area; and (ii) information made publicly available through doing an act anywhere in the patent area". Sections 7(2) and 7(3) of the 1990 Act set out the condition upon which an invention would not be taken to involve an inventive step when compared with the prior art base: "(2) For the purposes of this Act, 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 as it existed in the patent area before the priority date of the relevant claim, whether that knowledge is considered separately or together with either of the kinds of information mentioned in subsection (3), each of which must be considered separately. (3) For the purposes of subsection (2), the kinds of information are: (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; being information that the skilled person mentioned in subsection (2) could, before the priority date of the relevant claim, be reasonably expected to have ascertained, understood and regarded as relevant to work in the relevant art in the patent area." This case does not involve the use of two or more related documents. Section 7(3)(b) is therefore not material for present purposes. Sections 7(2) and 7(3), read with s 18(1)(b)(ii), take their place in the long history of the concept of the inventive step necessary to attract patent protection and are to be read in that context. Section 6 of the Statute of Monopolies, upon which British patent law was based after 1624, did not refer to an "invention". It excepted from the declaration that all monopolies were void "any Letters Patents and Grants of Privilege" for the "Making of any Manner of new Manufactures within this Realm, to the true and first Inventor and Inventors of such Manufactures, which others at the Time of Making such Letters Patents and Grants shall not use". Section 6 did not contain a requirement for an inventive step. Before the enactment of the Patents, Designs, and Trade Marks Act 1883 (UK), scrutiny of patent applications in the United Kingdom was largely concerned with compliance with formalities unless the patent was challenged. Want of novelty or utility or "lack of subject matter" could be raised in proceedings for the repeal of a patent taken by action of scire facias, brought in the name of the Crown pursuant to the fiat of the Attorney-General. The action was abolished by the 1883 Act but the grounds upon which it could be brought became grounds of revocation under that Act and were also available as defences to infringement proceedings. They also became, under s 86(3) of the Patents Act 1903 (Cth), grounds for the revocation of a patent by petition to the High Court or the Supreme Court of a State. The ground of want of inventive step, distinct from want of novelty and want of utility, as a basis for revoking a patent, was a product of case law under the rubric of "lack of subject matter". The term "obvious" emerged from the common law in relation to lack of subject matter in the late 19th century. Lord Herschell, in an early use of the term in Vickers, Sons & Co Ltd v Siddell, said: "the question remains, whether this ... was so obvious that it would at once occur to anyone acquainted with the subject, and desirous of accomplishing the end, or whether it required some invention to devise it." In Lockwood Security Products Pty Ltd v Doric Products Pty Ltd [No 2] this Court adverted to the historical development of want of inventive step at common law and the statutory ground, referring to obviousness, first created in the United Kingdom by the Patents and Designs Act 1932 (UK) ("the 1932 UK Act"), which the Court described as: "a different formulation of the old ground of 'want of subject matter' with the test becoming an overtly qualitative test rather than a quantitative one." Australia followed the 1932 UK Act with the enactment of s 100(1)(e) of the Patents Act 1952 (Cth) ("the 1952 Act") providing as a ground of revocation that a claim "was obvious and did not involve an inventive step, having regard to what was known or used in Australia on or before the priority date of that claim". Section 100(1)(e) was "the first legislative recognition in Australia that obviousness, or lack of inventive step, constituted a ground of revocation which was independent of lack of novelty". Under the 1952 Act, a prior disclosure did not support a conclusion of obviousness unless there was evidence that the disclosure was part of the "common general knowledge" at the relevant time. The term "common general knowledge" did not appear in s 100(1)(e). It was derived from the words "what was known or used in Australia". It had its origin in the common law of patents and was used in connection with want of novelty and want of subject matter. The relevant aspect of the latter objection was that the invention was "not proper subject-matter in view of the common knowledge of the time when it was patented". The content of common general knowledge, applied for the purposes of the 1952 Act, was explained by Aickin J in Minnesota Mining and Manufacturing Co v Beiersdorf (Australia) Ltd as: "that which is known or used by those in the relevant trade. It forms the background knowledge and experience which is available to all in the trade in considering the making of new products, or the making of improvements in old, and it must be treated as being used by an individual as a general body of knowledge." Importantly, under Australian law, it was not to be constructed out of a mosaic of prior publications. Publications existing before the priority date of a patent, in order to be relevant to want of inventive step under the 1952 Act, had to have become part of the common general knowledge. In Wellcome Foundation Ltd v VR Laboratories (Aust) Pty Ltd, Aickin J wrote the leading judgment, with which Gibbs ACJ, Stephen, Mason and Wilson JJ agreed, and said: "the question of obviousness involves asking the question whether the invention would have been obvious to a non-inventive worker in the field, equipped with the common general knowledge in that particular field as at the priority date, without regard to documents in existence but not part of such common general knowledge." (emphasis added) The same requirement applicable to the 1952 Act was reflected in the discussion of Minnesota Mining in the joint judgment in Aktiebolaget Hässle v Alphapharm Pty Ltd ("AB Hässle"). Relevant content was given to the term "obvious" by Aickin J in Wellcome Foundation Ltd, posing as the test: "whether the hypothetical addressee faced with the same problem would have taken as a matter of routine whatever steps might have led from the prior art to the invention, whether they be the steps of the inventor or not." The idea of steps taken "as a matter of routine" did not, as was pointed out in AB Hässle, include "a course of action which was complex and detailed, as well as laborious, with a good deal of trial and error, with dead ends and the retracing of steps". The question posed in AB Hässle was whether, in relation to a particular patent, putative experiments, leading from the relevant prior art base to the invention as claimed, are part of the inventive step claimed or are "of a routine character" to be tried "as a matter of course". That way of approaching the matter was said to have an affinity with the question posed by Graham J in Olin Mathieson Chemical Corporation v Biorex Laboratories Ltd. The question, stripped of references specific to the case before Graham J, can be framed as follows: "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]?" That question does not import, as a criterion of obviousness, that the inventive step claimed would be perceived by the hypothetical addressee as "worth a try" or "obvious to try". As was said in AB Hässle, the adoption of a criterion of validity expressed in those terms begs the question presented by the statute. The enactment of ss 7(2) and 7(3) followed a report and recommendations by the Industrial Property Advisory Committee ("IPAC") which proposed that: "For the purpose of determining inventiveness, any single prior disclosure or use should be capable of being considered against the background of all that is common general knowledge in the relevant field of art. On this basis the requirement of inventiveness will not be fulfilled if the knowledge imparted by the disclosure or use, combined with what is common general knowledge in the art, would render the claimed invention obvious to a person reasonably skilled in the art. However, it should not be possible for this purpose to combine two disclosures, two uses, or a disclosure and a use, where neither is within the common general knowledge of the art, except where one disclosure refers to another disclosure or use." IPAC recommended: "(i) that novelty and obviousness for standard patents be determined against a prior art base consisting of - • disclosures in recorded form publicly available anywhere in the world; • disclosures openly made, by oral communication, in Australia; and • what has been openly done and used in Australia; (ii) that, for these purposes (except where there is cross-referencing) it not be permissible to combine any two disclosures, or a disclosure and a use, or any two uses, save that in determining obviousness any single disclosure or use should be capable of being viewed in the light of the common general knowledge in the relevant field of art, at the relevant time; and (iii) that the common general knowledge in the art be treated as including disclosures in recorded form publicly available anywhere in the world which a skilled person working in the art at the time should reasonably have been expected to find, understand, and regard as relevant." The latter recommendation was not accepted and was not reflected in ss 7(2) and 7(3). The qualification it contained, however, was found in the government's response to Recommendation 13(ii): "It is to be understood, however, for the purpose of determining whether an invention is obvious, that it be permissible only to consider, in the light of the common general knowledge, a single disclosure or use which a skilled person working in the art in Australia at the time should reasonably have been expected to find or uncover, understand, and regard as relevant." In the 1990 Act, as the Court said in Lockwood [No 2], the threshold of inventiveness was raised compared with that set by the 1952 Act. The new threshold reflected the two IPAC recommendations which were accepted with the qualifications mentioned in the previous paragraph. The change effected by s 7(2) was that information publicly available at the priority date, but not part of common general knowledge, could be taken into account in addition to common general knowledge. The purpose of s 7(3) was broadly speaking: "the specification of the additional publicly available information ... which must be added to common general knowledge for the purposes of deciding whether an alleged invention is obvious when compared with the prior art base." While the range of disclosures that could support a finding of obviousness was widened, the content of the "inventive step" requirement was not changed. The test was still that posed under the 1952 Act by Aickin J in Wellcome Foundation Ltd in terms of the hypothetical addressee taking, as a matter of routine, steps which might lead from the prior art to the invention. That said, it was the text of ss 7(2) and 7(3) which governed the prior art information which could be invoked and how it could be invoked. The text of s 7(2) required, in unambiguous language, that "the onus to establish the absence of an inventive step rests upon the party challenging validity." It was, as Jessup J correctly observed in the Full Court, a deeming provision. Section 7(2) would defeat a claim for want of inventive step unless one of the alternative conditions set out in s 7(2), read with s 7(3), was satisfied. Those conditions involved the following elements:

KIEFEL J. For some time, HMG-CoA reductase inhibitors, which are referred to as "statins", have been prescribed by medical practitioners for the treatment of conditions such as hypercholesterolemia and for the lowering of low density lipoprotein ("LDL") cholesterol. The statins are typically taken once a day as tablets. The primary judge in the Federal Court of Australia (Jagot J) noted that according to the MIMS Annual 1998, recommended starting doses of statins were typically 10, 20 or 40 milligrams. Medical practitioners usually prescribed the lowest dose of statins to begin with, to minimise the risk of adverse side-effects associated with statins. If the target level of LDL cholesterol was not met and the dose had been well tolerated, it would be increased ("dose titration") over months. Dose titration aimed to increase the dose until the patient reached his or her target safely, but the practice was costly, because it necessitated a number of visits to the doctor and blood tests. It therefore risked patient non-compliance. As a result, titration often did not take place and the patient remained on the starting dose even though his or her target level was not reached. AstraZeneca AB and AstraZeneca Pty Limited (together "AstraZeneca") are respectively the registered proprietor and exclusive licensee of Australian Patent No 200023051 (which has been referred in the proceedings in the Federal Court as the "051 patent" and the "low dose patent", but is here referred to as "the Patent"). The specification for the Patent identifies the problem which the claimed invention seeks to overcome as finding dosages of alternative statins which have a similar or improved safety profile and are more efficacious in altering lipid levels than dosages of statins then being marketed. It discloses a method of treatment by the administration of what is called "the Agent" in a particular dose or dosage range. The Agent is rosuvastatin and pharmaceutically acceptable salts thereof. The method involved a starting dosage of rosuvastatin of 5-10 milligrams per day. The Patent's specification claimed that at these dosages LDL cholesterol is lowered "by an unexpected degree, and without any significant adverse side effects." The method of treatment described in the Patent, using rosuvastatin at the nominated dosages, has proved effective and commercially successful. The respondents to these appeals, Apotex Pty Ltd, Watson Pharma Pty Ltd (now Actavis Pharma Pty Ltd) and Ascent Pharma Pty Ltd ("the generic parties"), supplied generic compounds using rosuvastatin at like dosages. AstraZeneca claimed infringement of the Patent by that supply and obtained interlocutory injunctions. The generic parties sought revocation of the Patent. Her Honour the primary judge found the Patent to be invalid on three grounds: that AstraZeneca was not entitled to the Patent; that the invention disclosed in the Patent was not novel in light of two prior publications; and that the invention disclosed in the Patent did not involve an inventive step and was obvious within the meaning of s 7(2) of the Patents Act 1990 (Cth). A Full Court of the Federal Court (Besanko, Jessup, Foster, Nicholas and Yates JJ) overturned only the finding of lack of novelty and dismissed the appeals from her Honour's decision. On its appeals to this Court, AstraZeneca sought to agitate all of the grounds of invalidity which had been upheld by the Full Court. The generic parties raised other issues by notice of contention. One issue which arises in connection with the test of obviousness under s 7(2) of the Patents Act 1990 concerns her Honour the primary judge's approach to the characterisation of the invention disclosed by the Patent specification. Her Honour considered that although rosuvastatin was not part of the common general knowledge at the priority date, the invention presupposed its existence. Rosuvastatin could therefore be taken as a given in applying the test of obviousness. The reasons of the Full Court on the question of obviousness were given by Jessup J, with whom the other members of the Court agreed. His Honour observed that the primary judge's approach to characterising the invention had regard to the specification rather than the claims of the Patent. That approach appeared to follow the decision of a Full Court of the Federal Court in Apotex Pty Ltd v Sanofi-Aventis, although her Honour eschewed the use of the term "starting point", which had been used in that case, to describe the significance of rosuvastatin in testing the invention for obviousness. The decision in that case, his Honour observed, was at odds with a decision of another Full Court in Insta Image Pty Ltd v KD Kanopy Australasia Pty Ltd, which his Honour considered to have been correctly decided. The Commonwealth was granted leave to intervene in this matter. It submitted that this Court need not, and should not, deal with this aspect of the primary judge's reasons. A determination of the correctness of her Honour's approach may have significant effects for the Commonwealth as a party in pending proceedings concerning undertakings made to it as to damages, and which were brought by the Commonwealth upon an acceptance of the correctness of the decision in Apotex Pty Ltd v Sanofi-Aventis. Were it necessary to the determination of the real issues in this matter for that issue to be addressed, the consequences for other litigation would not be a weighty, or even a relevant, consideration. However, it is not necessary to consider this issue in order to determine the question of obviousness. The evidence shows that a person skilled in the art would have discovered the existence of rosuvastatin in any event. In its reply submissions, AstraZeneca conceded as much. The conclusion of invalidity on the ground of obviousness which was reached by the primary judge and by the Full Court is correct, for the reasons which follow. It is unnecessary to consider the other issues raised. The appeals should be dismissed with costs. Obviousness - the Patents Act 1990 provisions Section 18(1)(b) of the Patents Act 1990 provides that an invention is patentable if, so far as claimed in any claim, it is novel and involves an inventive step when it is compared with the prior art base existing before the priority date of the claim. In relation to deciding whether an inventive step was involved, "prior art base" is defined in the Dictionary to the Act to mean information in a document that is publicly available and information made publicly available through doing an act. However, s 7(2) makes plain that, subject to the effect of the provisions of s 7(3), what is spoken of as the prior art base in the assessment of an inventive step is the common general knowledge, which is to say, the general body of knowledge and experience which is available to all those who might consider making a new product or improving existing products in order to meet an identified need. At the priority date and the time the Patent was applied for, s 7(2) provided that: "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 as it existed in the patent area before the priority date of the relevant claim, whether that knowledge is considered separately or together with either of the kinds of information mentioned in subsection (3), each of which must be considered separately." Sub-section (3) relevantly provided: "For the purposes of subsection (2), the kinds of information are: (a) prior art information made publicly available in a single document ... being information that the skilled person mentioned in subsection (2) could, before the priority date of the relevant claim, be reasonably expected to have ascertained, understood and regarded as relevant to work in the relevant art in the patent area." The prior art information referred to in s 7(3) is information which is not part of the common general knowledge. The effect of permitting the use of this additional information is to raise the threshold for inventiveness in s 7(2). The s 7(2) question The primary judge considered the hypothetical person skilled in the relevant art for the purposes of s 7(2) (hereafter "the skilled person") to be a medical practitioner with specialised expertise in treating hypercholesterolemia and particular expertise in lipidology. The Full Court saw no reason to interfere with this finding. No party to these appeals challenged this aspect of her Honour's decision. The primary judge accepted the evidence of Professor Richard O'Brien and another witness as to the awareness of medical practitioners of the fact that a significant number of patients were not reaching their target levels of LDL cholesterol. Because of the ongoing management involved in dose titration, it was thought by practitioners to be desirable to have available new or improved statins which enable more people to achieve their target level at the first dose, which, according to ordinary prescribing practices, would be a dose at the lower end of the approved range. Aktiebolaget Hässle v Alphapharm Pty Ltd ("Alphapharm") stated the question to be answered to determine obviousness under the Patents Act 1952 (Cth). Section 100(1)(e) of that Act was in relevantly similar terms to s 7(2) of the 1990 Act except for the latter's addition to the matters to be considered, together with the common general knowledge, the prior art information referred to in s 7(3), which does not form part of the common general knowledge. Modifying the question stated in Alphapharm to allow for that further information and to be referable to the invention claimed in the Patent, the relevant enquiry is: Would a medical practitioner who specialises in treating hypercholesterolemia and who has particular expertise in lipidology, alone or in a notional research group, at the relevant date in all the circumstances, which include the common general knowledge considered separately or together with prior art information publicly available in a document relevant to the problem that many patients are unable to achieve their target LDL cholesterol level using available statins at currently prescribed dosages, directly be led as a matter of course to try rosuvastatin with a starting dosage of 5-10 milligrams in the expectation that it might well produce a useful alternative to or better drug than the most effective statin then available? Before a document containing prior art information can be used along with the common general knowledge for the purposes of the s 7(2) enquiry, it is necessary that it meet the requirements of s 7(3). In Lockwood Security Products Pty Ltd v Doric Products Pty Ltd [No 2] it was explained that prior art information which is publicly available in a single document is "ascertained" if it is discovered or found out, and "understood" means that, having discovered the information, the skilled person would have comprehended it or appreciated its meaning or import. The Court also explained that the phrase "relevant to work in the relevant art" is directed to publicly available information, not part of the common general knowledge, which the skilled person could be expected to have regarded as relevant to solving a particular problem, or meeting a long-felt want or need, as the patentee claims to have done. Lockwood [No 2] also explains that, in answering the question of obviousness, the information referred to in s 7(3), like that part of the prior art base which is the common general knowledge, is considered for a particular purpose. That purpose is to look forward from the prior art base to see what the skilled person is likely to have done when faced with a problem similar to that which the patentee claims to have solved with the claimed invention. It is this aspect of the s 7(2) enquiry which assumes particular importance on these appeals. In addressing s 7(2), it is to be borne in mind that the skilled person is an artificial construct, intended as an aid to the courts in addressing the hypothetical question of whether a person, with the same knowledge in the field and aware of the problem to which the patent was directed, would be led directly to the claimed invention. The statute's creation of the skilled person construct for this purpose is not to be taken as an invitation to deal with the question posed by s 7(2) entirely in the abstract. Whilst the question remains one for the courts to determine, the courts do so by reference to the available evidence including that of persons who might be representative of the skilled person. The evidence in this case The Patent had a priority date of 6 February 1999. The primary judge accepted that the existence of rosuvastatin was not part of the common general knowledge of the skilled person at that date. However, it was disclosed in two documents, which were referred to by the primary judge as the "471 Patent" and the "Watanabe article". The 471 Patent was filed by Shionogi, from whom AstraZeneca later obtained a licence in an endeavour to overcome the finding that it was not entitled to the Patent because it was not the inventor of rosuvastatin. The 471 Patent is the European patent for the compound rosuvastatin, which has an equivalent US patent. The specification for the Patent itself states that "the Agent" to which it refers, but not by the name rosuvastatin, is disclosed in European Patent Application, Publication No 0521471. The primary judge found that the 471 Patent is a sufficient disclosure of the compound rosuvastatin. The Watanabe article contains a reference to a range of new compounds, but it is the compound there referred to as S-4522 that is rosuvastatin, which is identified on the first page of the article and referred to as "the selected compound". It is described as having greater potency than some other statins then marketed and as having been tested on animals. It was said to be a promising candidate for development. The primary judge took Professor O'Brien to be representative of the skilled person who is the addressee with respect to the Watanabe article, which he found in the course of his searches for prior art information. Professor O'Brien's expertise qualified him as representative of the skilled person according to the primary judge's description. It is evident that Professor O'Brien's evidence in particular was considered by her Honour to be of the most assistance on the question of obviousness. Professor O'Brien gave evidence that a person in his position faced with the problem of patients not reaching their target LDL cholesterol levels would engage in a four-stage process. In the first place, the person would undertake, or cause to be undertaken, routine and conventional literature searches to discover any alternative statins. Secondly, the person would compare the results of those searches. Thirdly, the person would select from that comparison the best candidate to solve the problem. Lastly, the person would undertake, or cause to be undertaken, trials using that candidate statin to test its suitability at relevant dosages. All drugs must be subjected to animal studies and then clinical trials involving humans before they can be marketed and these trials are very expensive. Professor O'Brien explained that, to address the problem, he would be looking for a statin that would lower LDL cholesterol more efficaciously across its safe dose range than the most effective statin being marketed, atorvastatin. To be more efficacious, the statin must have greater efficacy than existing statins at the maximum safe dose to assist in treating patients with very high LDL cholesterol levels. It would be advantageous to have greater efficacy with at least similar safety at the lowest recommended starting dose as this would benefit patients who were intolerant of higher doses. Professor O'Brien conducted what the primary judge described as "routine and conventional literature searches" and identified five abstracts of documents of potential relevance to the problem. He requested a full text copy of those documents, which he identified by reference to their authors. One of them, the "Aoki article", disclosed a statin referred to as NK-104, which he considered to be promising. But it was the Watanabe article and the compound S-4522 which seemed to him more interesting because it suggested that the statin S-4522 had high potency with reduced side-effects and it had progressed to clinical trials. He regarded this as the most likely compound to solve the problem. As mentioned above, S-4522 was in fact rosuvastatin. Having selected this compound, Professor O'Brien gave evidence that the skilled person would have conducted further searches for other articles concerning it, including a patent search for the Japanese patent referred to in the Watanabe article. This was the Japanese Shionogi patent, which is to say the Japanese equivalent of the 471 Patent. He received an English language equivalent of the Japanese patent, which indicated that the author of that patent expected the compound to be effective across the typical dosage range of existing statins marketed in Australia. The information contained in the Watanabe article led Professor O'Brien to expect that this new statin would have a similar, or better, efficacy than atorvastatin. He expected it to be effective in lower dosages and considered that a starting dosage would be around 10 milligrams. The English language equivalent of the Japanese patent led him to expect that the starting dose would be 5-10 milligrams once daily, though he said that this would need to be confirmed by studies of human subjects. The Watanabe article indicated to him that the compound had been successful in both safety and efficacy on the pre-clinical animal trials, because it was not usual to commit to a clinical trial process, as the author reported, unless these trials were successful. The primary judge found, by reference to the evidence of Professor O'Brien, and of Dr Reece, another expert witness, that the skilled person would have found each of the Watanabe article and the 471 Patent, would have understood them and would have regarded each as relevant. The information in each of them would have led that person, as a matter of course, to undertake clinical trials in the expectation that the compound might produce a better result than was currently achieved in the field. AstraZeneca's contentions as to obviousness AstraZeneca's contentions as to obviousness may be divided into two stages. The first concerns the application of the s 7(3) stipulations and in particular the determination of whether a document is relevant and therefore eligible to be considered as part of the s 7(2) process. The second concerns the s 7(2) process for determining the question of obviousness. Here AstraZeneca submits that there is an evidentiary gap, because the skilled person would be faced with a number of alternative routes to follow and there was no evidence as to what that person would do. There must be alternative routes available because there is more than one document satisfying the test of relevance and each must be considered. Alternatively, if the Watanabe article can be relied upon alone, the skilled person could not be led by it to the dosage amounts that are part of the invention disclosed in the Patent. AstraZeneca submitted that in addressing the questions as to whether a document could reasonably be expected to be ascertained, understood and regarded by the skilled person as relevant to the problem, s 7(3) does not permit a process of comparison as between the documents in question and other documents not within the common general knowledge in order to select the document to be used in answering the question of obviousness under s 7(2). It submitted that, for the purposes of s 7(3), and in particular to determine its relevance, each document must be looked at independently. Although this point concerns the stipulations of s 7(3), AstraZeneca drew upon the concluding words of s 7(2) - "each of which must be considered separately" - in aid of the suggested prohibition on comparison in order to select a s 7(3) document. A consequence of its argument would appear to be that if a search for prior art information reveals more than one document, none of them could qualify as relevant to the problem if identifying a single document as relevant involved a process that required disregarding all other documents. The purpose of the requirements of separate consideration in s 7(2) is to prevent mosaicking, which is to say, selecting pieces of information from a number of prior publications or objects and assembling them such that the mosaic achieved reveals what is claimed in the patent in suit. This is reinforced by the stipulation in s 7(3)(b) that two documents not within the common general knowledge may be used for the purposes of s 7(2) only if the skilled person would treat them as a single source of information. AstraZeneca's submissions are not directed to the mosaicking of information. AstraZeneca's submissions elide the stipulations of ss 7(2) and 7(3), when the purposes of those sub-sections are quite distinct. The purpose of s 7(3) is to identify documents which may be used for the s 7(2) question of obviousness. The sub-section does so by reference to attributes of a document and the information contained in it, as seen through the eyes of the skilled person. So long as the information in the document has those attributes stipulated by s 7(3) it may be used for the purposes of the enquiry under s 7(2). This is essentially a question of evidence, not statutory construction. The evidence of Professor O'Brien and Dr Reece clearly showed that the Watanabe article, and other documents, could be expected to be ascertained by the skilled person, by routine and conventional searches. In oral argument in this Court, AstraZeneca conceded that the Watanabe article, and the 471 Patent, could be regarded as capable of ascertainment so that the question became one as to the application of s 7(2). In that event the fact that the information contained in those documents could be appreciated as relevant to solving the problem at hand would also appear necessarily to be conceded. Regardless, there can be no doubt, having regard to Professor O'Brien's evidence, that the Watanabe article conveyed sufficient information about the compound it referred to in order for him to appreciate the compound's usefulness. In some cases there may be an issue about the extent to which the information in the document in question may be supplemented or explained by other information. This is not such a case. Professor O'Brien understood from the Watanabe article, as the skilled person would, that the compound there referred to, being rosuvastatin, would be useful for the treatment of hypercholesterolemia and might be more potent than statins then being marketed. The limited comparison Professor O'Brien undertook of the compound in the Watanabe article with that disclosed in the Aoki article was not done with a view to determining the Watanabe article's relevance. It was by way of selecting the best candidate for the solution to the problem. It was necessary for him to select the best candidate because the clinical trials which would follow are extremely expensive. The difficulty for AstraZeneca with respect to this aspect of his evidence is that selecting the Watanabe article leads inevitably to the complete invention. This is why AstraZeneca challenges the selection of the Watanabe article over others. AstraZeneca accepts that the Watanabe article discloses the route to the invention, but it submits that this is not the only route to be considered. It argues that not only must each document qualifying as relevant be considered separately, but that each must be considered under s 7(2). None may be discarded. The situation which would then be achieved would be that the skilled person would have a number of routes to choose from. It is at this point that AstraZeneca submits that the claim of obviousness must fail, because witnesses such as Professor O'Brien did not say what they would do in such a situation. There is a level of unreality about the situation AstraZeneca seeks to create. Professor O'Brien did not need to comment upon what he would do faced with alternative routes, because that hypothetical did not arise, given the selection he had made of rosuvastatin. This evidence of Professor O'Brien that he would select rosuvastatin is sufficient to conclude that the skilled person would have selected the route that led to the invention of rosuvastatin. AstraZeneca further submitted that even if the Watanabe article was selected or preferred, it was not obvious that the skilled person would actually pursue that route to reach the invention. However, this submission was premised upon the information in that article being regarded as relevant and no more. This ignores the effect of Professor O'Brien's evidence which went further than to identify the compound disclosed as relevant. There is no step towards the invention unaccounted for in the evidence of Professor O'Brien. His evidence not only identified rosuvastatin as relevant to solving the problem to which the Patent is addressed; both he and Dr Reece identified rosuvastatin as warranting clinical trials. This evidence also provides the answer to AstraZeneca's final submission. The final submission was that, armed with the Watanabe article and the common general knowledge, the skilled person would not have been led directly to the invention because the starting dosages are an essential element of the invention and were not revealed by that article or by any other prior art document. This may be accepted. The dosages were revealed to AstraZeneca by clinical trials on humans, as inevitably they would be if undertaken. The point is that the Watanabe article contained sufficient information, including as to the results of the pre-clinical trials on animals, for Professor O'Brien to consider that clinical trials were warranted. Dr Reece was of the same view. Professor O'Brien's evidence about what the right dosages might be, although accurate, was largely speculative and this was not his area of expertise. However, Dr Reece, who has a background in clinical pharmacology and research, gave evidence that dose sizes which would be trialled could be expected to start from 5 milligrams, 10 milligrams and 20 milligrams. I do not understand AstraZeneca to contend that the starting dosages disclosed in the Patent would not be identified by normal clinical trials, which utilise certain standards and procedures. The evidence therefore shows that the skilled person would be led to the invention. Orders I agree with the orders proposed by the Chief Justice.

GAGELER AND KEANE JJ. We agree, for the reasons given by the Chief Justice and by Kiefel J, that the issue on which these appeals turn was correctly decided by the courts below. We wish only to make some brief comments upon the lack of merit in AstraZeneca's challenge to those decisions. In this case, special leave to appeal was granted principally to allow this Court to address difficulties said to attend the interpretation of s 7(2) and (3) of the Patents Act 1990 (Cth). The arguments advanced by AstraZeneca on these issues in this Court were without substance; they were also distinctly elusive in their presentation. The shifts which occurred in AstraZeneca's position during the course of argument should not be allowed to obscure the reality that these provisions give rise to no difficulties of interpretation material to the outcome of this case. The deference due to the plain and ordinary meaning of statutory language is not diminished because that language regulates intellectual property rights. Both courts below were right to conclude that the putative invention did not involve an inventive step. Given that conclusion, the other arguments on which the parties lavished much time, resources and enthusiasm are unnecessary to resolve. The patent The priority date of the patent in suit ("the Patent") is 6 February 1999. Before this date it was part of the common general knowledge that statins were administered to patients to lower their low-density lipoprotein (LDL) cholesterol levels. The problem in the common general knowledge at the priority date was to develop a new statin treatment that could bring more patients to their target blood cholesterol level without the need to resort to dose titration. AstraZeneca claimed that it solved this problem by inventing the method of treatment claimed in the Patent. Claim 1 of the Patent defined the method of treatment as: "A method of treating a patient suffering from hypercholesterolemia which comprises administration as a starting dose of a single, once daily, oral dose of 5 to 10 mg of [rosuvastatin], or a pharmaceutically acceptable salt thereof, in the form of a pharmaceutical composition." The decision of the primary judge The primary judge held that the existence of the method of treatment was disclosed by two pieces of prior art. One was a European patent application ("the 471 patent"), which disclosed that various compounds, including rosuvastatin (within a certain dosage range), were useful in the treatment of hypercholesterolemia. Her Honour found that the 471 patent would have enabled a person skilled in the art to proceed to the method of treatment claimed in the Patent. The other piece of prior art information was an academic article (referred to by the parties as "the Watanabe article") that described a compound, S‑4522 (rosuvastatin), as a "promising candidate for development" in relation to the treatment of hypercholesterolemia. Her Honour found that the Watanabe article would also have enabled a person skilled in the art to proceed to the method of treatment claimed in the Patent. These findings were based on the expert evidence of Professor O'Brien and Dr Reece. There was no challenge to Professor O'Brien's qualification to give evidence in relation to how a person skilled in the art would have gone about solving the problem in the common general knowledge. Professor O'Brien's evidence was that a person skilled in the art who encountered the problem would have engaged in a four‑step process to solve it. That process would have involved, as the first two steps, routine and conventional literature searches to discover alternative statins, and a comparison of the results of those searches. That comparison would have led to a selection of the best candidate to solve the problem. There would then have been trials using that selected statin to determine its efficacy at relevant dosages. Professor O'Brien gave evidence that he conducted routine and conventional literature searches as the first step in this process. Those searches generated hundreds of abstracts of scientific papers. Professor O'Brien gave evidence that his comparison of these papers identified the Watanabe article and another paper, referred to as the Aoki article (which concerned an agent described as NK‑104), as candidates to solve the problem. The Watanabe article led Professor O'Brien to ascertain the Japanese equivalent of the 471 patent, the English language version of which led him to expect that an appropriate starting dose for treatment would be five to 10 milligrams once daily, although this expectation would need to be confirmed by studies of human subjects. In this regard, Dr Reece's evidence was to the same effect. Professor O'Brien said he would have chosen rosuvastatin for treatment, although he would not have been critical of someone who chose NK‑104. This evidence led the primary judge to conclude that a person skilled in the art would have been led, as a matter of course, to try the method of treatment claimed in the Patent in the expectation of improved results for patients. Accordingly, the claimed method of treatment did not involve an inventive step. The appeals to the Full Court AstraZeneca appealed from the decision of the primary judge to the Full Court of the Federal Court of Australia (Besanko, Jessup, Foster, Nicholas and Yates JJ). In a separate concurring judgment, Jessup J dealt with the inventive step point. Jessup J upheld the primary judge's conclusion that the claimed invention was obvious in light of the common general knowledge together with either the Watanabe article or the 471 patent. His Honour's consideration of this issue involved two questions: "first, was there prior art information, of the kind referred to in [s 7(2)], which the skilled addressee 'could … be reasonably expected to have ascertained, understood [and] regarded as relevant' (within the meaning of [s 7(3)]); and secondly, if so, would the invention then have been obvious, in the light of the common general knowledge when considered together with that information, to the skilled addressee?" In relation to the first question, Jessup J held that it was permissible under s 7(3) to have regard to multiple pieces of prior art information "along the road to [the] destination" of assessing whether any single piece of prior art information could reasonably be expected to have been regarded as relevant to solving a problem in the common general knowledge. As his Honour rightly said: "It is true that, under s 7(2) ... the skilled person notionally knows nothing beyond the common general knowledge. But it is then assumed [by s 7(3)] that he or she will undertake the task of finding some additional information which is not part of the common general knowledge. The question is whether he or she could be reasonably expected to have ascertained (etc) the information. Such an assumed course of inquiry must necessarily take the person into the realm of information which is not within the common general knowledge. It is, in my view, wholly within the scheme of the subsection that he or she might well 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. … Ultimately, of course, there must be one document (or act) only which imparts the information which is to be added to the common general knowledge. But the sources which the skilled person would consult to decide what that document is, to come to an understanding of the information in it and to consider whether that information was relevant, are not confined to a single document." (original emphasis) This was sufficient to resolve the first question against AstraZeneca. As Jessup J appreciated, 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 s 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. AstraZeneca initially argued that s 7(3) precluded such a sorting process in the search for relevant information; but the pressure of argument led inevitably to the abandonment of that position. Once relevant information has been ascertained in accordance with s 7(3), the second question posed by Jessup J may be addressed: would the invention be obvious if the information had been considered by a person skilled in the relevant art together with common general knowledge? The inquiry contemplated by s 7(2) is whether the invention would have been obvious to a person skilled in the art in the light of the common general knowledge alone, or "together with" a single piece of prior art information ascertained pursuant to s 7(3). What s 7(2) requires, by the plain and ordinary meaning of its language, is that where multiple pieces of prior art information are available and capable of being regarded as relevant, each must be considered, one at a time, together with the common general knowledge to answer the question whether the invention is obvious. If the invention is obvious in light of the common general knowledge plus any one of the ascertained pieces of prior art information, then the patent is invalid for want of an inventive step. 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, and that this difficulty was not resolved by Professor O'Brien's evidence. It was said that the potential usefulness of both rosuvastatin and NK‑104 meant that it would not have been obvious to a person skilled in the art at the priority date to choose rosuvastatin rather than NK‑104 to treat hypercholesterolemia. On a fair view of Professor O'Brien's evidence, and indeed the view taken by the primary judge, Professor O'Brien's express preference for rosuvastatin means that this contention cannot be sustained. In any event, AstraZeneca's contention pursues a red herring. As the primary judge rightly said: "The fact that there were other potential statin candidates ... for development at the time ... which the skilled addressee would also have located as a matter of course, does not detract from the fact that the information in each of the 471 patent and the Watanabe article would have led the skilled addressee as a matter of course to try the claimed invention in the expectation that it might well produce a useful alternative to or a better result than currently achieved in the field." 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. It is also wrong to suggest, as AstraZeneca did, that the need for further testing of human subjects was an obstacle to a conclusion that rosuvastatin would have been tried as a matter of course in the expectation of a solution to the problem in the common general knowledge. 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. AstraZeneca's appeals should be dismissed with costs.

NETTLE J. With respect, I substantially agree with the reasons for judgment of French CJ and those of Kiefel J and wish to add only some brief observations on the meaning of ss 7(2) and 7(3) of the Patents Act 1990 (Cth). As French CJ and Kiefel J observe, the issue of central importance in these appeals was the construction of those provisions: more precisely, whether the person skilled in the art who is referred to in s 7(2) is permitted to have regard to more than one document when deciding whether there is a single document within the meaning of s 7(3)(a) which discloses prior art that in the light of common general knowledge renders an invention obvious. As French CJ and Kiefel J conclude, there is nothing in ss 7(2) or 7(3) which precludes the person skilled in the art from looking at more than one document (whether sequentially or comparatively or otherwise) for the purposes of determining the relevance of any single document. It is to be emphasised, however, that ss 7(2) and 7(3)(a) do not permit the person skilled in the art to combine information from other sources with the contents of the one document. The plain and ordinary meaning of the words in s 7(2) - "each of which must be considered separately" - is that the single document referred to in s 7(3)(a) must be capable of standing alone without interpretative or corroborative assistance from another document or other source of information apart from common general knowledge. The rectitude of that meaning is supported by the legislative history of ss 7(2) and 7(3) which is essayed in French CJ's reasons. One of the arguments advanced for the appellants was that, but for information that Dr Reece derived from the Thompson article that the trials referred to in the Watanabe article were Phase II trials, Dr Reece would not have concluded that rosuvastatin was an obvious choice to satisfy the need for an effective statin that did not require dose titration. If that had been so, it would have been a valid point of objection. In contrast to the exercise involved in ascertaining the relevance of the Watanabe article - for which purpose it was permissible for a person skilled in the art to consider other documents - when the person skilled in the art came to deciding whether the Watanabe article rendered the invention obvious, it was necessary for that person to exclude from consideration any information derived otherwise than from common general knowledge and the prior art disclosed in the Watanabe article. In fact, however, there is no basis in the objection. Both the primary judge and the Full Court approached the matter in accordance with that requirement. As Jessup J said, although Dr Reece's evidence was that the Watanabe article contained no safety data the result of either animal or human trials, the evidence also disclosed that trials of that kind would conventionally be carried out. Accordingly, carrying out the trials fell within the concept of working towards an invention with an expectation of success and that was consistent with the conclusion that the invention was obvious. I agree with the orders proposed by French CJ.