High Court unanimously rules Crestor patent invalid

AstraZeneca has lost patent protection for its blockbuster cholesterol-lowering drug Crestor (rosuvastatin).  In AstraZeneca AB v Apotex Pty Ltd (2015) 323 ALR 605, the High Court of Australia upheld the Full Federal Court's decision invalidating AstraZeneca's method of treatment patent which concerned the treatment of hypercholesterolemia by administering a once daily oral dosage of rosuvastatin. A copy of our previous report on the Full Court's decision is available here.

The High Court unanimously held that the claimed inventions of AstraZeneca's patent lacked an inventive step (i.e. were obvious), agreeing with the Full Federal Court and the primary judge.

At issue in the High Court was the test for inventive step: whether the invention as claimed would have been obvious to the skilled person in light of the common general knowledge ("CGK") as it existed in Australia before the priority date considered separately or together with prior art information contained in a single publicly available document (i.e. CGK or "CGK plus one").

As it then stood, the Patents Act provision related to inventive step required, in order to take into account a single document in addition to CGK when assessing inventive step, a person skilled in the art to have ascertained, understood and regarded as relevant the information contained in the document.  In this case there were two relevant documents that were identified by routine searches performed by experts for Apotex, in the context of seeking to invalidate AstraZeneca's patent.

Two main contentions were made by AstraZeneca on appeal concerning the test for inventive step:

  1. when determining whether a single document containing prior art information is “relevant” and therefore can properly be combined with the CGK, it is impermissible to engage in a process of comparison with other documents not within the CGK – that is, relevance must be determined by looking at the single document alone; and 
  2. CGK must be considered with each relevant prior art document in turn - when there is more than one relevant document, the skilled person would be faced with alternative paths to follow.  There was no evidence led by Apotex as to what the skilled person would do when faced with alternative routes and therefore the Court could not conclude that invention was obvious.

Both arguments were unanimously rejected by the High Court.

In relation to determining whether a prior art document is relevant, the High Court held that the skilled person is permitted to "sort through all manner of information with a view to finding something that is regarded as relevant".  In fact, the High Court held that the skilled person can even use combinations of documents from any source for the purposes of determining whether a single piece of prior art is relevant.

As to AstraZeneca’s second contention, the High Court held that the fact that there was more than one pathway for the skilled person to follow was irrelevant. The question is not whether it would have been obvious to the skilled person to choose one pathway over the other, the question is whether either one of the pathways would have directly led as a matter of course to the claimed invention.

The High Court ultimately concluded that taking into account the CGK plus one document (i.e. following one of the two pathways available to a person skilled in the art), the claimed invention was obvious and lacked inventive step. 

The statutory provision requiring that a piece of prior art be ascertained, understood and regarded as relevant for the purposes of assessing inventive step was removed from the Patents Act 1990 (Cth) as a result of the Raising the Bar amendments introduced in April 2013.  This limits the implications of the High Court ruling to patents filed before 1 April 2002.

What’s patentable and what’s not? IP Australia guidance post Myriad

In October 2015, the High Court unanimously held in D’Arcy v Myriad Genetics Inc. (2015) 325 ALR 100 ("Myriad") that isolated nucleic acid encoding the mutant BRCA1 polypeptide did not constitute a manner of manufacture and was not patentable subject matter in Australia. Our analysis of the High Court’s decision can be found here.

Following the decision in Myriad, IP Australia deferred consideration of pending patent applications claiming RNA or DNA, and engaged in public consultation in relation to a proposed new examination practice.  IP Australia had, prior to Myriad, routinely accepted patent claims directed at isolated nucleic acid.

IP Australia’s new examination practice has been recently published and can be found here.

Initially, IP Australia proposed to reject claims to isolated nucleic acid specifically coding for a polypeptide but accept most other claims to naturally occurring products, including claims to non-coding isolated nucleic acid such as regulatory DNA.  This approach relied upon an unduly narrow interpretation of the High Court’s decision.

IP Australia’s position has since shifted.  In the final version of its revised examination practice, claims to isolated nucleic acids, whether human or non-human and whether coding or non-coding will be rejected on examination by IP Australia. 

In addition to clarifying the position in relation to isolated nucleic acid, the new examination practice outlines the key questions examiners should ask in order to determine whether biological inventions constitute patentable subject matter.  These are:

  1. What is the substance of the claim (not merely its form)?
  2. Has the substance of the claim been "made" or changed by man, or is "artificial"?
  3. Does the invention have economic utility?
  4. Does the invention as claimed represent a new class of claim?

Patent applications that were “suspended” pending revisions to the examination practice will now be considered by IP Australia.