AstraZeneca (AZ) won a critical round in its bid to defend blockbuster cholesterol drug Crestor from generic competition in the US after an appeals court came out in support of its patent on the drug.
The court upheld an earlier district court ruling that the 314 patent on the active substance in Crestor – rosuvastatin calcium – is valid and enforceable, preventing generic drugmakers from launching copycat versions of the drug until it expires in 2016.
The decision safeguards AZ’s biggest-selling product at a time when the company is struggling to refill its portfolio from its pipeline.
Crestor sales were $4.6bn in the first nine months of 2012 – with half that total coming from the US market – and the brand has held up reasonably well so far despite a flood of generic versions of Pfizer’s rival drug Lipitor (atorvastatin) entering the market since the latter’s US patent expired November, 2011.
AZ said that the generic pharma companies challenging the patent may try to overturn the appeals court ruling, which was upheld by a 2 to 1 vote. To do so they would have to go to the US Supreme Court.
The generic companies Apotex, Aurobindo, Cobalt, Glenmark, Mylan, Par, Sandoz, Sun, Teva and Torrent have been trying to overturn AZ’s patent protection on Crestor since 2007, alleging either that the Crestor patent was invalid or that their own drugs did not infringe AZ’s intellectual property.
All the generic drugmakers with the exception of Apotex have said that their versions of rosuvastatin infringed upon the 314 patent but said that the patent itself was invalid because AZ its partner Shionogi held an earlier substance patent on rosuvastatin.
The plaintiffs also argued that that AstraZeneca and Shionogi had withheld certain critical information about the drug from the US patent office, but this claim was dismissed by the court.