Pfizer Inc.’s new experimental heart drug is dead, but the dual approach the company was testing — boosting good cholesterol while lowering the bad — is very much alive, specialists said Monday.
A drug already on the market, Niaspan, raises good cholesterol without serious risks, and a large federal study is testing it with statin medications — the very thing Pfizer was trying to do before being forced to abandon its drug, torcetrapib, because of safety problems.
For consumers, the main fallout may be a delay in getting a new medicine that avoids Niaspan’s chief side effect — a hot prickly sensation called flushing that patients hate but that also can be minimized, doctors said.
“It does set us back years” in developing an alternative drug, said the Cleveland Clinic’s Dr. Steven Nissen, who led one recent study on the doomed Pfizer drug.
It also “raises the safety bar for new agents ... to a very high level,” because deaths and heart attacks were significantly greater among those taking the experimental Pfizer drug, said Dr. Allen Taylor of Walter Reed Army Medical Center. He led the most promising study yet of Niaspan plus a statin drug and has consulted for all of the major companies involved in these research efforts.
On Saturday, Pfizer stopped its torcetrapib study after an independent safety board spotted more deaths and other serious complications among patients getting the experimental drug.
Trying to boost good cholesterol
For decades, doctors have focused on lowering LDL or bad cholesterol, as the main way to cut the risk of heart problems. Millions of Americans already take statins, sold under such brand names as Lipitor and Zocor, to lower LDL, which ferries fats from food into the bloodstream.
But lots of statin users suffer heart attacks and strokes anyway, so doctors increasingly have been looking at boosting HDL, or good cholesterol — which escorts fat out of the blood and to the liver to be disposed — to further lower risk.
Niacin, a type of B vitamin, does this, and Niaspan, made by Kos Pharmaceuticals Inc., is an extended-release version of niacin that minimizes flushing. It has been on the market since the late 1990s, although niacin has been sold as a vitamin for more than 50 years.
At an American Heart Association conference two years ago, Taylor reported that Niaspan plus statin drugs kept blockages in heart arteries from getting worse. There also were fewer heart attacks, deaths, strokes and other problems among those taking Niaspan plus statins versus statins alone in his study.
Pfizer’s torcetrapib appeared to be a much more potent booster of HDL but had “a laser-guided missile approach” in the way it worked that may have made it uniquely dangerous, said Taylor, who served on a Pfizer advisory panel for the drug.
“My suspicion is torcetrapib failed because of its mechanism of action,” agreed Dr. Greg Brown of the University of Washington in Seattle, who is leading the big federal study of Niaspan plus the statin Zocor. It involves several thousand patients at 72 medical centers in the United States and Canada.
How to reduce side effects
Taking Niaspan at bedtime along with aspirin and a low-fat snack can minimize the hot flashes, or flushing problem, Taylor said.
“If you stay with it for a couple of months, your body develops a tolerance to the flush,” Brown said. “We’ve had people on niacin for 20 years. They refuse to give it up now because they’ve had fathers die at age 40” and don’t want to suffer the same fate.
Merck & Co. also is testing an HDL-booster: its own extended-release niacin combined with a prostaglandin blocker, a drug to prevent some of the flushing. Drugs called fibrates also raise HDL, but carry risks when combined with statins.
Some newer diabetes drugs may boost HDL. Nissen will present results of one such study at a cardiology meeting in March. He and others also will provide results of other studies on the Pfizer drug that may shed light on whether it was uniquely dangerous.
Finally, there are many ways to improve cholesterol without the risks of medication.
“We know we can raise HDL by asking people to exercise more, to stop smoking and lose weight,” Taylor said.