On September 2 2015 the High Court handed down a widely anticipated decision in AstraZeneca AB v Aptoex Pty Ltd.(1) The court unanimously dismissed AstraZeneca’s appeal, holding that AstraZeneca’s patent was invalid because it was obvious and therefore lacked the requisite inventive step within Sections 7(2) and 7(3) of the Patents Act 1990.
Compounds known as ‘statins’ are used to treat hypercholesterolemia and other related conditions.
This treatment often involves initially prescribing the lowest possible dosage, followed by gradual increases (known as ‘dose titration’). The purpose of dose titration is to lower a patient’s cholesterol levels gradually while minimising any adverse side effects from the statins. However, this necessitates repeated medical appointments and blood tests. As a result, patients often remain on lower doses and the treatments are therefore less effective.
AstraZeneca was the owner and exclusive licensee of the patent, which specified a method of treatment designed to address the problems of dose titration.(2) The patent prescribed the use of rosuvastatin in small doses (5 to 10 milligrams per day) which were said to lower cholesterol levels “by an unexpected degree, and without any significant adverse side effects”.(3)
The respondents (Apotex Pty Ltd, Actavis Pharma Pty Ltd and Ascent Pharma Pty Ltd) supplied generic compounds which used rosuvastatin at similar doses to those described in the patent.
AstraZeneca brought proceedings before the Federal Court, alleging patent infringement. The respondents cross-claimed to have the patent revoked.
The Federal Court held that the patent was invalid on three grounds, including that the invention disclosed in the patent was obvious within the meaning of Section 7(2) of the act. The court found that the method of treatment had already been disclosed by two pieces of prior art:(4)
- a European patent application which suggested that various compounds – including rosuvastatin – were useful in treating hypercholesterolemia (the ‘471 patent’); and
- an academic article describing rosuvastatin as a “promising candidate for development” in relation to hypercholesterolemia (the ‘Watanabe article’).
AstraZeneca appealed to the Full Court, which overturned the Federal Court’s finding of lack of novelty, but otherwise dismissed the appeal. AstraZeneca sought special leave to appeal to the High Court.
Special leave was granted so that the High Court could provide guidance as to the interpretation of Sections 7(2) and 7(3) of the act.(5)
The central issue before the High Court was the construction of Sections 7(2) and 7(3) of the act, and specifically, whether the person referred to in Section 7(2) can have regard to more than one document in the obviousness analysis.(6)
At the time, Sections 7(2) and 7(3) of the act provided as follows:(7)
“(2) …an invention is 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:
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.” (Emphasis added.)
The primary judge regarded the skilled person referred to above as “a medical practitioner with specialised expertise in treating hypercholesterolemia and particular expertise in lipidology”. This was not disputed on appeal.(8)
The High Court’s findings on the obviousness issue can be summarised as follows:
- The obviousness enquiry involves two questions. The first is whether there is prior art information which the skilled person could be reasonably expected to have ascertained, understood and regarded as relevant. If so, is the invention obvious in light of the common general knowledge when considered together with that information?
- Section 7(3) assumes that the skilled person will look for additional information that is not part of the common general knowledge (eg, the 471 patent and Watanabe article).(9)
- There is nothing in Section 7(2) or 7(3) which prevents a person from looking at more than one document in order to determine the relevance of a single document under Section 7(3)(a).(10)
- A person cannot combine information from other sources with the contents of the single document in order to establish obviousness.(11) This is to prevent ‘mosaicking’.(12)
- Section 7(2) requires that where multiple pieces of prior art information are available and capable of being regarded as relevant, each must be considered independently alongside the common general knowledge, in order to determine whether the invention is obvious. If it is, then the patent is invalid.(13)
While the High Court’s interpretation of Sections 7(2) and (3) of the act was a straightforward analysis of the relevant provisions, it provides useful guidance on the obviousness enquiry – in particular, that where multiple pieces of information are available and relevant, each must be considered independently alongside the common general knowledge.
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(1)  HCA 30.
(2)  HCA 30 at 38  (Gageler and Keane JJ).
(3)  HCA 30 at 27  (Kiefel J).
(4)  HCA 30 at 39  (Gageler and Keane JJ).
(5)  HCA 30 at 38  (Gageler and Keane JJ).
(6)  HCA 30 at 43  (Nettle J).
(7) Section 7(3)(b) of the act was not considered relevant by the court.
(8)  HCA 30 at 30  (Kiefel J).
(9)  HCA 30 at 30  (Kiefel J)
(10)  HCA 30 at 41  (Gageler and Keane JJ); 43  (Nettle J).
(11)  HCA 30 at 43  (Nettle J).
(12)  HCA 30 at 8  (French CJ).
(13)  HCA 30 at 41  (Gageler and Keane JJ).
This article was originally edited by, and first published on, www.internationallawoffice.com.