For the second time in four months, the Food and Drug Administration's Division of Drug Marketing, Advertising, and Communications (DDMAC) has warned AstraZeneca on advertisements promoting its cholesterol drug Crestor--calling suggestions that the drug is better that Pfizer's Lipitor "misleading."
A spokesperson for AstraZeneca (nyse: AZN - news - people) said the letter, a copy of which was obtained by Forbes.com, only applies to one ad campaign in the context of one specific portion of data from one study.
AstraZeneca continues to believe that based on other comparative data it will be able to claim that Crestor is better at lowering bad cholesterol than all other statins.
In a letter sent to AstraZeneca, an officer at DDMAC noted that the efficacy of Crestor's top 40-milligram dose was similar to that of 80 milligrams of Lipitor in the study referenced by AstraZeneca.
"The TV and print ads make false or misleading claims regarding the superiority of Crestor," Christine Smith, a regulatory review officer at DDMAC wrote in the letter.
"All cholesterol drugs simply aren't the same," one ad intoned, according to the letter.
Print advertisements made their own rhyming claims.
If not then compare," says a third.
Pfizer's (nyse: PFE - news - people) Lipitor rules the cholesterol market and is prescribed more than all other similar drugs combined.
Merck (nyse: MRK - news - people) and Schering-Plough (nyse: SGP - news - people) have introduced their own drug, Vytorin, which gets efficacy by combining Merck's Zocor with another cholesterol-lowering drug.
Crestor, meanwhile, has been faced with critics who say it may not be as safe as its competitors--claims with which AstraZeneca and some researchers vigorously disagree but which have had a noticeable affect on sales.