Researchers Deal Crestor Another BlowMay 24, 2005 | USA TODAY
The study is the latest stumbling block for Crestor, launched by AstraZeneca (AZN) in 2003, which had hoped it would compete with market leader Lipitor, made by Pfizer. Last year, it was one of several drugs FDA scientist David Graham said deserved further scrutiny, and it recently survived a challenge from an advocacy group seeking to have it removed from the market.
Researchers writing in the journal Circulation found that Crestor caused significantly more cases of a serious muscle disorder called rhabdomyolysis and kidney problems than competitors Zocor, Pravachol or Lipitor, with sixfold more of these side effects in Crestor patients than in those taking Lipitor.
But all of those side effects taken together were relatively rare, with Crestor causing 28 for every million prescriptions, Zocor 13 per million, Lipitor 4.3 per million and Pravachol 3.5 per million, says lead researcher Richard Karas of Tufts-New England Medical Center.
AstraZeneca sold $908 million of Crestor worldwide last year, but it remains fifth in market share in the USA. The study was released after the market closed. AstraZeneca stock fell 3.6% in after-hours trading to $41.23.
In a statement, AstraZeneca said it disagrees with the study. Crestor's safety profile is "in line with other marketed statins and is a highly effective cholesterol-lowering therapy," the company said.
The study draws upon a Food and Drug Administration database that consumer advocates have used to challenge the safety of other drugs. But the FDA and the author of the new study say the database is difficult to interpret and that Crestor's risks do not appear to outweigh its benefits.
"I would choose to use Crestor in patients who need very aggressive (cholesterol) lowering," says Karas, who has gotten funding from the drug's maker, AstraZeneca. "We're not raising concerns over the safety of statins, and we don't want to exaggerate concerns over Crestor."
Using those same FDA reports, the advocacy group Public Citizen called in 2004 for Crestor to be taken off the market, saying it was linked to rhabdomyolysis at a rate 6.2 times that of other drugs in its class combined, and was linked to a higher rate of kidney damage.
But in March, the FDA analyzed the same data and said it could not find convincing evidence that Crestor posed a greater risk of either condition.