Australian High Court dismisses AstraZeneca’s Rosuvastatin appeal

AstraZeneca AB v Apotex Pty Ltd [2015] 301

On 2 September 2015, the Australian High Court unanimously dismissed AstraZeneca’s appeal regarding the validity of the low dose Rosuvastatin patent for the treatment of hypercholesterolemia.  This case was appealed from a decision made last year by the Full Federal Court in which AstraZeneca’s patent was held invalid for lack of inventive step.  The High Court held that the invention as claimed lacked an inventive step within the meaning of s7(2) and 7(3)  of the Patents Act 1990 (the Act).

Brief History of the case

This case concerned Australian patent 200023051 (the ‘051 Patent) to AstraZeneca, which claims a low dose of Rosuvastatin, marketed under the drug name CrestorTM.  AstraZeneca initiated an infringement suit against the generic manufacturer Apotex, who in response sought revocation of the ‘051 patent.

At first instance, the Federal Court found the ‘051 Patent was invalid on three grounds; lack of entitlement, lack of novelty in light two pieces of prior art, and lack of inventive step in light of the common general knowledge (s7(2) of the Act)2.

This decision was subsequently appealed to the Full Federal court and a panel of five Judges overturned the lack of novelty finding, but upheld the primary judge’s decision concerning obviousness3. Following this decision in August 2014, AstraZeneca was granted special leave to appeal to the High Court, Australia’s highest court.

The High Court Decision

The High Court unanimously dismissed the appeal holding that the ’051 Patent was obvious in light of the common general knowledge when considered with either of the two prior art documents under s7(2)and 7(3) of the Act.

Under these sections of the Act an invention can be found to lack inventive step if it would have been obvious to a notional skilled person in the light of the common general knowledge.  The Act allows the skilled person to have regard to documents not part of the common general knowledge, which a person skilled in the art would have reasonably been expected to have ascertained, understood and regarded as relevant.  In Australia, such documents may not be combined to attack on the basis of inventive step.
In the High Court judgement there was discussion about the requirements for a reference to be ascertained, and the basis on which a reference that has been ascertained may be combined with the common general knowledge.

AztraZeneca asserted the presence of an evidentiary gap, as the person skilled in the art would be faced with a number of alternative routes to follow, in the form of multiple pieces of prior art, and there was no evidence to guide them to the correct document that would in turn lead to the claimed invention.

In finding the ’051 Patent invalid for obviousness, the High Court rejected this argument with Nettle J stating at paragraph [120]: “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”.

Ultimately it was held there was no error in Full Federal Courts reasoning and approach regarding the question of inventive step finding and that the ’051 Patent invalid in light of a s7(3) reference and the common general knowledge.

As the High Court found that the appeal failed on this first ground and they did not consider the other questions raised.  Notably the court was quiet on the question regarding the correct starting point for the skilled addressee in considering the inventiveness of a claimed invention.


This decision brings to a close the long-running court proceedings concerning AstraZeneca’s Rousvastatin patents.  The High Court dismissed the appeals with costs, now enabling  the Generic Parties to seek compensation of losses incurred during the earlier interlocutory injunction granted to AstraZeneca. This decision also carries significance for the Australian law on inventive step, confirming that it is possible to select a prior art document as the basis for assessing obviousness from one many possible relevant documents.
This article was written by Rosemary Manhire-Heath.

If you have any specific enquiries about the rosuvastatin decision in Australia, please contact Paul Jones or Debra Tulloch.


1.  Apotex Pty Ltd v AstraZeneca AB (No 4) [2013] FCA 162

2.  Astrazeneca AB & Anor v Apotex Pty Ltd [2014] FCFCA 99