AstraZeneca has been issued a generic challenge to its blockbuster cholesterol drug Crestor (rosuvastatin calcium) by Canada’s Cobalt pharmaceuticals.

Cobalt is seeking approval to sell a copycat version of Crestor aiming to launch its version before the drug’s patents expire – AstraZeneca’s Crestor is covered by patents valid until 2016, 2020 and 2021.

AstraZeneca has a 45-day window to decide whether to take Cobalt to court. If it does, the FDA will not be able to approve generic versions for another 30 months.

AstraZeneca said its plans to evaluate Cobalt’s allegations and certifications and has full confidence in the intellectual property portfolio protecting Crestor.
 
Crestor, which helps reduce the artery-clogging form of cholesterol in the blood, was AstraZeneca’s third-best selling product last year, bringing in $2.03 billion. The global market for cholesterol treatments, the biggest-selling category of drugs, totals about $21.6 billion a year, according to IMS Health.

The market for brand-name cholesterol-lowering drugs is expected to continue to shrink following the introduction of a generic form of Merck’s Zocor (simvastatin).

According to AstraZeneca’ CEO David Brennan, generic simvastatin has put pressure on Crestor, Pfizer’s Lipitor and Schering-Plough’s Vytorin.

Researchers are scheduled to release new data on Crestor’s use in heart failure at the American Heart Association meeting in Orlando, FL, on Nov. 5.

Meanwhile, AstraZeneca today reported a 15% drop in net income, brought about by restructuring and acquisition costs and generic competition on other key products.

Net income for the quarter ending Sept. 30 was $1.34 billion, or 90 cents a share, down from $1.59 billion, or $1.01 a share, a year earlier.

Sales of the drugmaker’s top-seller, the ulcer treatment Nexium, fell 1% to $1.29 billion as a resut of  generic competition.