Trial Cholesterol Drug Strikes Out
Torcetrapib Fails to Slow Plaque Buildup in Arteries
WebMD News Archive
Torcetrapib Linked to BP Rise
In the new studies, torcetrapib boosted HDL cholesterol just like it was
supposed to. However, there were negative effects as well.
In one study, known as ILLUSTRATE, 1,188 patients with heart disease were
randomly assigned to receive the statin Lipitor plus torcetrapib or Lipitor
Results showed that torcetrapib boosted levels of HDL by 61% and decreased
LDL by 20%. However, people on the drug experienced a 4.6-point increase in
blood pressure. As shown by imaging, there was no significant difference in
plaque buildup between the two groups.
Similarly, in the RADIANCE 1 and 2 studies, people who suffered from
inherited cholesterol disorders were randomly assigned to treatment with the
Lipitor-torcetrapib combination or Lipitor alone.
Torcetrapib again led to robust increases in HDL cholesterol and dramatic
decreases in LDL cholesterol. However, there was again no benefit in plaque
buildup. Again, blood pressure increased, although less than in the ILLUSTRATE
“You would think the LDL decrease is more important than the blood pressure
increase, so even ignoring HDL, we should have seen benefit,” says researcher
John Kastelein, MD, of the Academic Medical Center in Amsterdam. “Something
very strange is going on here,” he tells WebMD.
They researchers say they will continue to analyze the data.
There are still many unanswered questions, says James Stein, MD, of the
University of Wisconsin Medical School in Madison and chairman of the session
at which the results were presented.
"The big question that every scientist and everybody on Wall Street
wants to know is whether or not it was the drug or the approach to raising HDL
cholesterol. Most people seem to think it's unique to torcetrapib alone, but we
still don’t know,” he says.
Nissen says there are three possible reasons why the drug failed. First,
increases in blood pressure may have countered any beneficial effects. Second,
the rise in blood pressure may reflect some other unique toxicity that doomed
the drug to fail. Or third, the strategy itself may be flawed.
HDL Shots Offer Hope
Also at the meeting, researchers reported that infusions of a reconstituted
form of HDL slightly slowed plaque buildup in arteries.
“They took blood, extracted HDL, turned it into a product, and reinfused it.
The results offer a glimmer of hope,” Nissen says.