Pfizer Inc. halts tests of a highly touted new cholesterol drug because of an unexpected number of deaths and other complications. Testing on the drug, torcetrapib, was ceased after more people in the drug group died than in the placebo group.
The drug was unique in that it raises HDL, the "good" kind of cholesterol -- the currently popular statin drugs work only to lower bad cholesterol.
The decision to scrap the new drug means that researchers who hoped for a chemical fix for heart disease will have to keep looking. "Our hopes have been dashed by this," says Steven Nissen, head of the American College of Cardiology, "and it means we won't have a powerful HDL-raising drug, probably before 2011."
Pfizer had poured resources into testing the drug. Nissen headed a multi-center trial to see if the drug could reduce cholesterol buildup in arteries. Over the weekend, the company got word about another trial that simply looked at whether the drug saved lives or cut back on illnesses.
The analysis involved 15,000 people. Half took torcetrapib and the statin drug Lipitor; the other half just took Lipitor.
There were 51 deaths among those taking just Lipitor, and 82 deaths in the group that also took torcetrapib.
"Either something else was causing harm," Nissen says, "or the cholesterol, the HDL levels we were building up, weren't protecting the patients."
The company immediately stopped the trial; it is studying the data to see what caused the extra deaths. Scientists will look especially hard at conditions related to hypertension, since the drug is known to slightly elevate blood pressure.
A Pfizer spokesman says the company has several similar drugs in the pipeline. They're trying to figure out whether the problems with torcetrapib come from lowering HDL cholesterol, lowering a particular type of HDL cholesterol, or from some unique characteristic of the torcetrapib molecule itself.
Researchers involved in the torcetrapib trial are now calling their patients and telling them to stop taking it.