The combination of Pfizer's Lipitor (atorvastatin) and the company's investigational CETP inhibitor torcetrapib raises HDL ('good') cholesterol and lowers LDL ('bad') cholesterol.
Phase II results of the combination were presented at the American Heart Association annual meeting in Dallas yesterday.
The dose-ranging study randomised nearly 500 patients to 12 weeks' treatment with torcetrapib 60 mg and Lipitor 10, 20, 40 or 80 mg. The combination was well tolerated, raising HDL cholesterol by 44-66% and lowering LDL cholesterol by 41-60%.
High levels of LDL cholesterol are a well-established risk factor for cardiovascular events. However, since HDL cholesterol prevents the build-up of atheroslerotic plaque within the arteries, low HDL is increasingly recognised as an important independent contributor to cardiovascular risk.
CETP (cholesterol-ester transfer protein) regulates the transfer of cholesterol from the HDL to the LDL particle. By inhibiting CETP, torcetrapib prevents this transfer and raises HDL to improve the lipid profile. Phase III clinical studies are now in progress to test whether the combination of torcetrapib and Lipitor will achieve further reductions in cardiovascular events beyond those seen with the statin alone.
Pfizer is investing some $800 million dollars in the Phase III programme for Lipitor/ torcetrapib as part of its bid to reach the market ahead of rivals also battling to develop a drug with a dual action on both LDL and HDL.
Source: Sue Lyon at the AHA in Dallas, USA.