'We are the most excited we have been in decades,' says cardiologist Dr. Christopher Cannon, shown here in 2006. Cannon led the study of the cholesterol drug anacetrapib. (Steven Senne/Associated Press)

An experimental drug boosted good cholesterol so high and dropped bad cholesterol so low in a study that doctors were stunned and voiced hopes for an entirely new way of preventing heart attacks and strokes.

"We are the most excited we have been in decades," said Dr. Christopher Cannon of Brigham and Women's Hospital in Boston, who led the study of the drug for Merck & Company.

The drug, anacetrapib (an-uh-SEHT'-ruh-pihb), will not be on the market anytime soon. It needs more testing to see if its dramatic effects on cholesterol will translate into fewer heart attacks, strokes and deaths. Merck plans a 30,000-patient study to answer that question, and it will take several years.

But the magnitude of the new medicine's effects excited doctors at an American Heart Association conference in Chicago, where results were presented on Wednesday.

'Data look spectacular'

"The data look spectacular, beyond what anybody would have expected," said Dr. Robert Eckel, a University of Colorado cardiologist and past president of the heart association. "It's like a rocket to Jupiter versus one to the moon. I can think of many of my patients who could use the drug right now."

For years, doctors have focused on lowering blood concentrations of low-density lipoprotein — LDL, or bad cholesterol — to cut heart risks. Statin medicines such as Lipitor and Zocor do this, and generic versions cost less than $1 a day. But many statin users still suffer heart attacks, so doctors have been trying to get LDL to very low levels and to boost high-density lipoprotein — HDL, or good cholesterol.

Anacetrapib, described as the first drug of its kind, helps keep fat particles attached to HDL, which carries them in the bloodstream to the liver to be disposed of.

Merck says it is too soon to estimate how much the drug would cost, but analysts say such a medication could mean billions for its maker, though it would have to prove cost-effective by preventing heart attacks, strokes and deaths.

The Merck-sponsored study tested anacetrapib in 1,623 people already taking statins because they were at high risk of a heart attack — half had already had one, and many others had conditions like diabetes.

'It's like a rocket to Jupiter versus one to the moon. I can think of many of my patients who could use the drug right now.'— Dr. Robert Eckel

An LDL level of 100 to 129 milligrams per decilitre is considered good for healthy people, but patients like these should aim for under 100 or even under 70, guidelines say. For HDL, a score of 40 to 59 is OK, but higher is better.

After six months in the study:

• LDL scores fell from 81 to 45 in those on anacetrapib, and from 82 to 77 in those given dummy pills.
• HDL rose from 41 to 101 in the drug group, and from 40 to 46 in those on a placebo.

Such large changes have never been seen before, doctors say, and these improvements persisted for at least another year that the study went on.

Too early to cite heart benefits

Over the years, other drugs have generated excitement in early research, then turned out to be risky or not so effective when tried on many more patients.

The Merck study was too small to tell whether anacetrapib lowered deaths, heart attacks or other heart problems. But the trend was in the right direction, with fewer of those cases among patients on the drug. The anacetrapib group also needed significantly fewer procedures to fix clogged arteries.

Importantly, there were no signs of the blood pressure problems that led Pfizer to walk away from an $800-million US investment in torcetrapib, a similar drug it was developing four years ago.

"This one looks far more potent, without the serious side-effects that led to failure," said Dr. Douglas Weaver, a cardiologist at Henry Ford Health System in Detroit and past president of the American College of Cardiology. "If proven effective, this will really change practice in the same way Aspirin and statins have."

Results of the study were published online by the New England Journal of Medicine. Some study leaders have consulted for Merck and makers of other heart drugs.