Death of the ‘starting point’ approach: AstraZeneca v Apotex

A recent decision of the Full Court of the Federal Court of Australia, AstraZeneca AB v Apotex Pty Ltd (2014) 312 ALR 1 (‘AstraZeneca’) has clarified the tests for novelty and inventive step under the Patents Act 1990 (Cth).

In relation to inventive step, the Full Court in AstraZeneca marked its disapproval of the ‘starting point’ approach previously adopted by an earlier Full Court.  Instead, the Full Court emphasised the objective nature of the test, namely, a comparison between the invention as claimed and common general knowledge, considered alone or together with relevant prior art information.

As regards novelty, the Full Court held that, while common general knowledge may be used to construe a prior art document, it is not permissible to add common general knowledge to the document when comparing the prior art with the claimed invention.

Background

AstraZeneca appealed to the Full Court from the trial judge’s decision in Apotex v AstraZeneca (No 4). At first instance AstraZeneca’s patents were held to be invalid on a number of grounds, including novelty and inventive step.  The appeal concerned two patents, AU 200023051 (‘‘051 Patent’) and AU 200051842 (‘‘842 Patent’).  The ‘051 Patent claimed methods of treating a patient suffering from hypercholesterolemia comprising administration of a particular dosage of the pharmaceutical compound, rosuvastatin.  The ‘842 Patent claimed pharmaceutical compositions comprising rosuvastatin and an inorganic salt.

Inventive step and the ‘starting point’ approach

One of the issues which the Full Court was required to consider in the assessment of inventive step was the so-called ‘starting point’ approach:  does an invention involve an inventive step where the invention is an obvious solution to a problem, but the problem is not common general knowledge nor known in the relevant prior art?  The ‘starting point’ approach had previously been adopted by the Full Court in Apotex v Sanofi-Aventis [2009] FCAFC 134 (‘Sanofi’), and has particular application in cases where the patent specification outlines a particular problem (and sets out to solve that problem), but where that problem is not necessarily common general knowledge in the relevant field. In Sanofi, the Full Court analysed the inventive concept of the patent by reference to the specification, and specifically the identification of the problem which the patent set out to solve. It then considered whether that inventive concept was obvious in light of the relevant prior art information.

In the context of assessing inventive step for the rosuvastatin patents, the specific question was whether the compound rosuvastatin and its properties should be treated as the “starting point”, since such knowledge of rosuvastatin was acknowledged in the relevant patent specifications (but was not found to be common general knowledge at the relevant dates).If so, AstraZeneca would need to show that the particular method of treatment and compositions claimed were inventive when considered in light of knowledge of the rosuvastatin compound. However if the starting point did not include knowledge of rosuvastatin it would be much easier for AstraZeneca to establish inventiveness.

The generic parties also argued that even adhering strictly to subsection 7(2) as the “starting point”, a correct interpretation of that subsection allows for comparison of the invention with any publically available information (as defined in the Patents Act as the “prior art base”), and is not limited to a comparison with the common general knowledge and the information defined in subsection 7(3) (‘prior art information’), which is importantly limited by the requirement that it be information which the skilled person could be reasonably expected to have ascertained, understood, regarded as relevant. This requirement will commonly exclude patent specifications from subsection 7(3), given that skilled persons in many areas of technology might not be expected to consult such documents in the course of innovation.

A four-judge majority of the Full Court held:

  • Subsection 7(2) of the Patents Act requires inventive step to be assessed by reference to common general knowledge, considered separately or together with the relevant prior art information in subsection 7(3). The argument for a wider reading of subsection 7(2) was rejected;
  • The body of knowledge and information against which inventive step is assessed cannot be enlarged by reference to the description of the invention in the patent specification, including description of any problem that the invention is directed at solving;
  • If a problem described in the specification is common general knowledge or prior art information, then awareness of the problem will be attributed to the skilled addressee.  However, where the problem is not common general knowledge or s.7(3) information, then the description in the specification cannot be used to attribute awareness of the problem to the skilled addressee;
  • Therefore, the ‘starting point’ approach adopted in Sanofi should not be applied to the assessment of inventive step under the Patents Act 1990.

In the result, the Full Court upheld the trial judge’s conclusion that the ‘051 Patent was obvious, even taking the more general starting point. Because the majority held that the ‘842 Patent lacked novelty, it was not necessary to decide whether it also lacked inventive step.  However, the majority of the Court indicated that if the ‘842 Patent were novel, it would have allowed AstraZeneca’s appeal on inventive step because the trial judge erroneously treated knowledge of rosuvastatin as a given starting point.

Novelty and the use of common general knowledge

The Full Court also upheld AstraZeneca’s appeal that the trial judge erred in assessing novelty of the ‘051 Patent by reading common general knowledge into a prior art document (Watanabe).

Although common general knowledge may be used to construe a prior art document, the Full Court held that it is not permissible to add common general knowledge to the document to result in information which the prior art document alone does not disclose.

As a result, the Full Court found the ‘051 Patent novel.  However, because it dismissed AstraZeneca’s appeals on inventive step and entitlement, the order to revoke the ‘051 Patent was not disturbed.

Implications for patent validity going forward

In some cases, the Full Court’s rejection of the starting point approach is likely to make it significantly more difficult for would-be opponents to patents to establish invalidity on the grounds of obviousness. This will particularly be so, where the patentee/patent applicant is aware of previous technology which is not in the common general knowledge. In such cases, even where such prior art is identified in the patent specification, it cannot be taken into account unless it is shown to be prior art information. Where the technology is described in an earlier patent specification, there may be difficulties, at least in some fields, in showing that the patent would have been ascertained by a person skilled in art, so as to be treated as prior art information.  In those cases, it seems that a person may be able to obtain a patent for making an obvious addition to existing technology of which that person was aware.

On the other hand, the Full Court’s approach removes potential subjectivities introduced by the starting point approach. The Full Court noted that using a starting point approach would mean that an invention could be obvious if made by one inventor who was aware of certain relevant information (and took it upon themselves to include this information in the patent specification), but not obvious if made by another, who was not aware of such information.

The question as to the appropriate interpretation of section 7(2), and whether the invention should be compared to the “prior art base” as defined or only the common general knowledge together with relevant prior art information within section 7(3) is an interesting one. As the Full Court made clear, the High Court has taken the narrower interpretation on several occasions and the Full Court was bound by that interpretation. Nevertheless, the web of references created by subsections 7(2) and (3) and the definitions of “prior art base” and “prior art information” in the Patents Act 1990 do not inevitably lead to an obvious answer. To some extent these difficulties may be overcome by the Raising the Bar amendments which remove the requirement that relevant prior art information could reasonably have been ascertained, understood and regarded as relevant, bringing section 7(3) closer to the prior art base. However the way in which section 7(3) will be interpreted post-Raising the Bar has not yet been tested and this may raise some questions of its ownll.

In the meantime, the importance of analysing obviousness arguments in a very detailed manner, particularly before embarking on evidence preparation cannot be overemphasised. As Rosuvastatin shows us, getting the right starting point can be crucial.