In an important decision handed down on Tuesday, Justice Jagot of the Federal Court held that three patents relating to the blockbuster drug Crestor (rosuvastatin) were invalid and liable to be revoked.  The decision will have important implications for companies considering launching their own generic rosuvastatin products given that total sales of Crestor for 2012 were about $350m.

The patentee, AstraZeneca, which markets Crestor, asserted that various generic companies would infringe three of its patents which relate to rosuvastatin:

  1. A “low dose patent”, which claims a method of treating high cholesterol (hypercholesterolemia) by administering  to a patient a low dose of rosuvastatin;
  2. A “HeFH patent”, which claims a method of treating high cholesterol caused by an inheritable genetic mutation by administering rosuvastatin to a patient; and
  3. A “cation patent”, which claims a pharmaceutical composition containing rosuvastatin and an inorganic salt which has particular chemical properties (that is, an inorganic salt in which the cation is multivalent, the inorganic salt is not a hydrotalcite, and the counter anion to the inorganic salt is not a phosphate).

Her Honour held that the claims of all three patents were liable to be revoked on the grounds that they are not novel or inventive. Additionally, in relation to the low dose patent, her Honour found that AstraZeneca was not entitled to the grant of this patent and, in relation to the HeFH patent, this patent did not disclose a ‘manner of manufacture’.

Justice Jagot’s comments on the role of expert evidence in patent cases and her findings that the “starting point” for assessing whether a patent is inventive (that is, discloses an inventive step) are interesting from the point of view of patent practice.

Keep an eye out for our detailed analysis of these issues in the coming days.

Given the size of the market for Crestor and the attempts by challengers to enter the market in late 2011-early 2012 this dispute is, we suspect, far from over!