NEWSFLASH: This morning the High Court of Australia unanimously dismissed AstraZeneca’s appeal from the Full Federal Court’s August 2014 decision in which AstraZeneca’s Crestor patents were held invalid.

AstraZeneca AB and AstraZeneca Pty Ltd (together, AstraZeneca) are the patentee and exclusive licensee of Australian Patent No 200023051 (the 051 Patent). The 051 Patent protected AstraZeneca’s blockbuster cholesterol lowering drug CRESTOR (rosuvastatin) and claims as an invention the treatment of hypercholesterolemia (i.e. high blood cholesterol) via the administration of rosuvastatin at a starting dose of 5 to 10 mg.

AstraZeneca claimed that the supply of rosuvastatin products by generic manufacturers Apotex Pty Ltd, Actavis Pharma Pty Ltd and Ascent Pharma Pty Ltd (the Generic Parties) would infringe the 051 Patent and, with this in mind, the Generic Parties challenged both the validity of the 051 Patent and AstraZeneca’s entitlement to it.

At first instance, the primary judge held that the 051 Patent was invalid; finding that it lacked both novelty and an inventive step, and that AstraZeneca was not entitled to it. The Full Federal Court (the Full Court) allowed an appeal by AstraZeneca in relation to the issue of novelty as well as the primary judge’s reliance on the “starting point” approach adopted from Apotex Pty Ltd v Sanofi Aventis (2009) 82 IPR 416 (Apotex v Sanofi) to conclude that the claimed invention was obvious in light of the common general knowledge (CGK) alone, as it existed at the priority date.

However, the Full Court upheld the primary judge’s decision that the 051 Patent was invalid for lack of inventive step in light of the CGK coupled with either of two prior art documents which disclosed the potential for use of rosuvastatin in the treatment of hypocholesteremia.

AstraZeneca appealed the Full Court’s findings in relation to lack of inventive step and entitlement and the Generic Parties raised issues with the Full Court’s findings in relation to novelty and the “starting point” approach to assessing obviousness by way of a notice of contention.

Inventive step

Section 7(2) of the Act deems a claimed invention to involve an inventive step unless it would have been obvious to a person skilled in the relevant art (PSA) in light of the CGK existing at the priority date of the claim, whether the CGK is considered either alone or together with any single piece of prior art falling with the scope of the requirements in section 7(3) of the Act. In this regard, section 7(2) states that each piece of prior art “must be considered separately”.

The form of section 7(3) of the Act in force at the relevant time restricted the prior art to information contained in a single act or single document, or in a combination of acts or a combination of documents that the PSA would treat as a single source of information, that the PSA could “be reasonably expected to have ascertained, understood and regarded as relevant…”

The debate centred on two key issues, namely:

  1. whether, in circumstances where a particular piece of prior art would only be “ascertained, understood and regarded as relevant” by the PSA following routine and conventional literature searches, section 7(2) of the Act requires obviousness to be assessed in light of the CGK and that piece of prior art alone, without having regard to the alternative information that would be uncovered by the PSA whilst conducting those searches; and
  2. whether it is permissible to use information from the body of the specification to determine the “starting point” for an assessment of obviousness in circumstances where that information does not form part of the CGK and is not otherwise disclosed in any prior art falling within the scope of section 7(3) of the Act (i.e. the “starting point” issue”).

Construction of section 7(2) and (3) of the Act

At the priority date of the 051 Patent, the CGK included a recognised desire or need to develop new statin treatments to address efficacy-related issues identified in relation to the statins already existing in the market. Expert evidence led at trial established that:

  1. when faced with the challenge of finding new statin treatments, the PSA would have undertaken routine and conventional literature searches to identify alternative statins, compared the documents uncovered by those searches and, on the basis of that comparison, selected what they considered to be the best candidate for further development;
  2. had this process been followed at the priority date of the 051 Patent, there were four section 7(3) documents that PSA could have been expected to ascertain, understand and regard as relevant. Each document disclosed the potential usefulness of a particular statin or statins in treating hypercholesterolemia, with two documents referring only to rosuvastatin (the “Publications”), one document referring only to another statin known as “NK-104” and the final document referring to rosuvastatin, NK-104 and two other statins.

With this in mind, the Full Court upheld the primary judge’s finding that the invention claimed in the 051 Patent would have been “obvious to try with an expectation of success” in light of the CGK plus either one of the Publications. That is, the Full Court considered that the disclosure of rosuvastatin as potentially useful in treating hypocholesterolemia in either of the Publications, when coupled with the CGK of usual starting doses for statins, rendered the invention claimed in the 051 Patent “obvious”.

In reaching this conclusion, the Full Court rejected AstraZeneca’s contention that it would not have been obvious to the PSA to try rosuvastatin in light of either of the Publications and the CGK, having regard to other alternative statin, NK-104, which the PSA would also have identified whilst finding the Publications. AstraZeneca’s expert confirmed that, when faced with both options, the PSA could just have reasonably chosen to develop NK-104 instead of rosuvastatin. However, relying on the words “considered separately” in section 7(2) of the Act, the Full Court held that, as NK-104’s potential as an alternative candidate was not within the CGK nor disclosed in either of the Publications, it could not be taken into account in determining whether the claimed invention was obvious in light of either of the Publications.

The High Court gave AstraZeneca’s inventive step arguments short shift. In answer to the first question, the High Court said that there is nothing in the plain and unambiguous language of the Act which prevents a PSA from sifting through various results arising from a search in order to identify a relevant s 7(3) document:

“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” per Gageler & Keane JJs

The Court said that the test was clear: where multiple pieces of prior art are available and capable of being regarded as relevant, each must be considered separately, one at a time. If the invention is obvious in the light of the CGK plus any one of the pieces of prior art, then the patent is invalid for want of an inventive step.

Almost inevitably, once the High Court found against AstraZeneca on this issue, a finding of lack of inventive step followed and the appeals were dismissed. The High Court in that regard made specific mention of AstraZeneca’s argument 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. The Court held that s 7(2) does not “invite a consideration of the notional addressee’s motivation to carry out any tests that would need to be done”. As French CJ put it, “[t]he notional person is not an avatar for expert witnesses whose testimony is accepted by the court. It is a pale shadow of a real person”.

“Starting Point” approach

While the decision in respect of ss 7(2) and 7(3) meant that the High Court did not need to consider the “starting point” issue, it is worth reflecting on the Full Court’s conclusion in that regard. Adopting the approach taken by the Full Court in Apotex v Sanofi, the primary judge held that, although rosuvastatin did not form part of the CGK at the priority date of the 051 Patent, disclosures in the body of the specification provided rosuvastatin as the “starting point” for an assessment of obviousness. On this basis, Her Honour characterised the “inventive concept” in the 051 Patent as the starting dose of rosuvastatin. With this in mind, Her Honour held that the claimed invention in the 051 Patent was obvious in light of the CGK alone, which included knowledge of common starting doses of other statins.

This approach was rejected by the Full Court, which found that information in the body of the specification that does not form part of the CGK and is not otherwise disclosed in a prior art document falling within the scope of section 7(3) of the Act cannot be used to determine the obviousness of the claimed invention. Having regard to the fact the rosuvastatin was not within the CGK, the Full Court held that the claimed invention was not obvious in light of the CGK alone. In reaching this conclusion, the Full Court distinguished Apotex v Sanofi on the basis that the patent in suit in that case fell under the 1951 iteration of the Act.

This ends the long-running battle over CRESTOR in Australia.