Australian rosuvastatin patents found to be invalid

In a decision handed down on 5 March 2013, the Federal Court of Australia found three patents protecting the cholesterol medication, Crestor™ (rosuvastatin), to be invalid and liable to be revoked (Apotex Pty Ltd v AstraZeneca AB (No 4) [2013] FCA 162).

Background

The three patents, all to AstraZeneca, were challenged by Apotex Pty Ltd, Watson Pharma Pty Ltd and Ascent Pharma Pty Ltd. They claim the use of rosuvastatin to treat hypercholesterolemia (AU2000023051) and heterozygous familial hypercholesterolemia (AU2002214165), as well as rosuvastatin in a pharmaceutical formulation (AU2000051842). The patent landscape for rosuvastatin is unusual in Australia in that there is no API patent protecting the base molecule. AstraZeneca therefore had to rely on secondary patents.

Watson, Ascent and Apotex (the ‘generic parties’) each proposed to supply generic versions of the rosuvastatin product in tablet form. The proposed launch resulted in AstraZeneca alleging infringement of each of the three rosouvastatin patents. In response, the generic parties each alleged that the claims on which AstraZeneca relied to assert infringement were invalid and should be revoked.

Summary of the Decision

The Honourable Justice Jagot found that Australian patent 2000023051 ‘did not involve a patentable invention (on the ground of lack of novelty, lack of inventive step or obviousness, and no manner of manufacture)’ and further found that AstraZeneca lacked entitlement to the claimed invention, because they had not listed the correct person as inventor. Australian patents 2002214165 and 2000015842 were both found liable to be revoked as ‘the claims did not involve a patentable invention on the grounds of lack of novelty, lack of inventive step or obviousness, and no manner of manufacture’.

Conclusion

It was concluded that all the claims of 2000023051 were invalid and the patent should be revoked. The claims on which AstraZeneca relied to assert infringement of 2002215165 and 2000015842 were also found to be invalid and liable to revocation. It was further stated that it would be unlikely that any claims of these patents could be sustained. Finally, the court ordered that the generic parties ‘should immediately be released from any undertakings and interlocutory injunctions that they have given or by which they are bound’ and that ‘AstraZeneca’s applications for relief against infringement should be dismissed’.

Comment

Considering Crestor™ was the highest earning product for AstraZeneca in 2012, it will be interesting to see if this decision is appealed. We should know the answer to this question in about one months’ time.

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

This article was written by Dr Ellen Reid.