The results of a clinical trial involving nearly 2,000 patients suggest that AstraZeneca’s Crestor is more effective in getting patients with high cholesterol to their treatment goals than two big-selling rivals.

The MERCURY II study found that Crestor (rosuvastatin) was more effective than either Pfizer’s Lipitor (atorvastatin) or Merck & Co’s Zocor (simvastatin) at both reducing low-density lipoprotein or ‘bad’ cholesterol and bringing patients to their target LDL cholesterol goals, as laid down by Adult Treatment Panel (ATP) III guidelines.

The data could help Crestor in its bid to win market share in the hugely lucrative statin market from Lipitor, currently the top-selling drug in the world with 2005 sales of over $12 billion, although both these products are likely to come under pressure in the latter half of this year with both Zocor and Bristol-Myers Squibb’s Pravachol (pravastatin) losing patent protection in the USA.

Faced with the genericisation of the statin market, the top players will be hoping that robust data on meeting treatment goals will help offset the effects of generic competition by ensuring that their products are used in favour of generics in patients that need potent cholesterol-lowering treatment.

MERCURY II enrolled patients at high or very high risk of developing cardiovascular disease because of their elevated blood cholesterol levels, and looked at the effect of switching them from Lipitor or Zocor to Crestor after eight weeks’ treatment.

At the end of a second eight-week treatment period, 43% of those switched from Lipitor 10mg to Crestor 10mg met their ATP targets, compared to 22% of those who stayed on the Pfizer drug. 53% of those on Lipitor 20mg who switched to the same dose of Crestor met their targets, compared to 35% of those who stayed on their initial therapy.

16% of patients taking Zocor 20mg met ATP goals, but this increased to 40% if they were switched to Crestor 10mg, while the corresponding proportions were 34% and 53%, respectively, for those switched from Zocor 40mg to Crestor 20mg.

Meanwhile, Pfizer also launched a broadside at its generic rivals after revealing economic data suggesting that Lipitor achieves greater reductions in heart attacks, strokes and cardiovascular procedures than Zocor, providing cost savings for healthcare payors in long-term hospitalizations and surgical costs.

"Even if the current US price of Zocor were reduced by 75%, Lipitor patients could still achieve better cardiovascular outcomes at an increase to payors of less than one dollar a day," said Dr Gregg Larson, vice president cardiovascular medical at Pfizer.

A summary of the data is published in the current issue of the journal Circulation.