Merck & Co has presented eagerly-anticpated data on its experimental drug anacetrapib which shows that it more than doubles the level of good cholesterol and cuts the bad type nearly in half, without increasing blood pressure.

Results of the Phase III, 1,623-patient, 18-month DEFINE study have been presented at the American Heart Association meeting in Chicago. The data show that anacetrapib, a cholesterylester transfer protein (CETP) inhibitor reduced low-density lipoprotein (LDL), or 'bad' cholesterol by 40% from 81mg/dL to 49 mg/dL.

It also more than doubled the level of high-density lipoprotein cholesterol (HDL) which helps clear lipids from the bloodstream — from 40 mg/dL to 101 mg/dL. This was done without raising blood pressure, which has particularly impressed researchers as the latter led in part to the termination of lat-stage trials of another CETP inhibitor, Pfizer's much-touted torcetrapib at the end of 2006.

Christopher Cannon of the Brigham and Women’s Hospital in Boston, and lead investigator on DEFINE, said “Anacetrapib has a knock-your-socks-off effect on HDL and a jaw-dropping effect on LDL”. He added that these changes are striking because virtually all the patients in the study were already taking cholesterol-lowering drugs and achieved previously unattainable levels of good and bad cholesterol".

Although the study was not powered to assess the effects of anacetrapib on cardiovascular events, fewer of the latter occurred in the anacetrapib group than in the statin-only group. Prof Cannon said "this agent provides us a very strong add-on treatment to statins", adding that "if the cardiovascular effects are borne out by future research, it would be a very promising approach to reducing cardiovascular events in patients with or prone to atherosclerosis".

Michael Mendelsohn, head of the cardiovascular franchise at Merck Research Laboratories, said that these results are promising "and serve as the basis for our decision to further develop anacetrapib," which will be studied further in a large cardiovascular clinical outcomes trial.

A four-year, 30,000-patient study will begin next year and observers believe that anacetrapib has the potential to be an enormous seller. Merck thinks so too and last month, Daniel Bloomfield, head of clinical and translational medicine, cardiovascular, told PharmaTimes World News he believes the drug may "change the landscape of heart disease".