MONDAY, Nov. 14 (HealthDay News) -- Preliminary research
suggests that a single injection of a man-made protein might lower
levels of "bad" cholesterol.
Given in the abdomen, AMG145 reduced low-density lipoprotein
(LDL) cholesterol levels among a group of healthy volunteers. The
shot turned off a newly identified cholesterol regulator, PCSK9,
which interferes with the liver's ability to clear bad cholesterol
from the bloodstream.
The findings were presented Monday at the American Heart
Association (AHA) annual meeting in Orlando, Fla. The study was
funded by AMG145 manufacturer Amgen Inc.
High cholesterol is a major risk factor for heart disease. The
first step toward lowering cholesterol is typically lifestyle
changes, which include eating a low-fat diet and regular physical
activity. For some, medications such as statins must be added to
get cholesterol levels where they ought to be. Even this is not
enough to get everyone's numbers into the safety zone, and not
everyone can tolerate currently available medications. An LDL of
less than 100 mg/dL of blood is considered optimal.
Study author Clapton Dias, medical sciences director of clinical
pharmacology and early development at Amgen, in Thousand Oaks,
Calif., said this shot could be given as an add-on to current
cholesterol-lowering therapies for people who are not getting as
low as they should be or as a standalone treatment for people who
can't tolerate existing lipid-lowering drugs.
"Cardiovascular disease is the number one cause of death in the U.S., and while statins are very effective, a good proportion of people are not meeting their goals, and in this setting the shot could be a valuable addition," he said.
The study included 54 men and two women aged 18 to 45 who did
not have elevated cholesterol levels. Participants received one of
five doses of the new drug delivered via shot or intravenously or a
placebo. Researchers measured LDL cholesterol levels for 85 to 113
days after treatment.
The new drug did hit its target, PCSK9, and decreased levels of
LDL cholesterol by up to 64 percent. There were also decreases seen
in levels of total cholesterol and apo-B (tiny fat particles in the
blood that also increase the risk for heart disease). Levels of
triglycerides and "good" HDL cholesterol were not altered by the
medication, and there were no serious side effects reported. Now,
researchers are testing the new shot in people who have high
Cardiologists were cautiously optimistic about the novel
Former AHA President Dr. Ralph Sacco said that it is too early
to make any predictions about what role, if any, this therapy will
have in lowering cholesterol levels, but it could one day fill an
"Even though statins are so effective at lowering cholesterol and reducing risk for heart disease and stroke, they do need to be taken every day and they can have certain side effects in some people," he said. Statin side effects can include liver damage and/or muscle pain.
"This new shot may provide a more long-lasting approach, especially if it could be given once a month," Sacco said.
Dr. Dan Rader, director of preventive cardiology at the
University of Pennsylvania, said that PCSK9 is "the hottest target
for new treatments to lower LDL cholesterol." And these study
results will probably fuel that fire, he added.
"A 60-plus percent reduction in LDL with a single dose of this antibody is impressive," he said. "It is the early days, but the data look strong. We now need more data with people who have repeated dosing and are followed for longer periods of time," Rader added.
"There are still plenty of people who can't achieve adequate LDL levels with existing drugs, including statins," he noted. Plus, "people may find it easier to get a shot every two weeks or monthly than to take a pill every day."
Research presented at meetings should be considered preliminary
until published in a peer-reviewed medical journal.
Learn about existing treatments for high cholesterol at the
American Heart Association.