Medication Made From Synthetic HDL Cholesterol Can Help Remove Artery Blockages, Study Finds
A drug made from a synthetic form of HDL, known as "good" cholesterol, can quickly stop and sometimes reduce blockages of plaque in artery walls that can lead to heart attacks, according to a small preliminary study published in Wednesday's issue of the Journal of the American Medical Association, the Washington Post reports. Researchers said the findings could offer "for the first time the possibility of a drug that could actually rapidly reverse heart disease," according to the Post (Stein, Washington Post, 11/5). The drug, ApoA-1 Milano, is derived from a mutant protein, apolipoprotien A-1, identified almost thirty years ago by scientists in a rural village in Northern Italy (Winslow, Wall Street Journal, 11/5). The protein is an important component of HDL's ability to clear LDL, or "bad" cholesterol, from the body and is "unusually aggressive" at doing so, the Los Angeles Times reports. In the study, researchers measured the size of the atherosclerotic plaques in 47 patients with acute coronary syndrome, all of whom had chest pains, high levels of cholesterol and partial artery blockages (Maugh, Los Angeles Times, 11/5). The patients were then divided into two groups; 36 of the patients received two different doses of the drug in 30-minute intravenous injections once a week for five weeks, while the other 11 patients received a placebo (Wall Street Journal, 11/5).
The size of the atherosclerotic plaques was measured again following the five-week treatment, and researchers found that those who received ApoA-1 had a 4.2% decrease in the volume of plaque in their coronary arteries, while those who received the placebo had a slight increase in plaque volume (Kolata, New York Times, 11/5). The decrease is 10 times the reduction in plaque volume that occurs after years of taking statin drugs, which work to limit LDL cholesterol, unlike ApoA-1, which boosts HDL levels, USA Today reports. The study also found that the benefit of ApoA-1 was even more evident in treating large, inflamed plaque-filled arterial bulges that can burst and potentially cause heart attacks, reducing them by as much as 34% (Sternberg, USA Today, 11/5). In addition, the drug changed the composition of the remaining plaque by removing triglycerides and inflammatory cytokines, making the plaque "more stable and less likely to fragment," the Los Angeles Times reports (Los Angeles Times, 11/5).
Study leader Steven Nissen, a cardiologist at the Cleveland Clinic, said, "This is the first convincing demonstration that targeting good cholesterol can benefit patients with heart disease" (Wall Street Journal, 11/5). Nissen added that "there is going to be a frenzy of activity to understand what happened, why it worked, and how we can do this for the most patients at the least cost." Dr. Daniel Rader of the University of Pennsylvania School of Medicine wrote in an accompanying editorial, "The results of this study are surprising to even the most optimistic supporters of the concept of targeting HDL as a therapy for atherosclerosis" (Los Angeles Times, 11/5). Rader said that the "biggest and by far the most surprising thing is that it can happen so quickly. ... It is surprising enough that it makes us all want to see it replicated in a larger study" (New York Times, 11/5). Roger Newton, president and CEO of Michigan-based Esperion Therapeutics, which manufactures ApoA-1, said that the study "validated the whole HDL hypothesis -- that it is something that could change the way medicine is practiced." Speaking on behalf of the American Heart Association, Susan Bennett, clinical director of the George Washington University Hospital Women's Heart Program, said that the study is "extremely preliminary. But it is very intriguing."
The study "could mark a milestone" in the search for new ways to treat heart disease because the drug targets "the underlying source of many heart attacks," the Post reports (Washington Post, 11/5). The Journal reports that study could have "a profound effect" on the study of heart disease but notes that the study was not large enough to have "statistically meaningful" comparisons between the effects of the drug and the placebo (Wall Street Journal, 11/5). According to the New York Times, the results of the study must be confirmed, and then a larger study needs to be conducted to show that the drug's reduction of plaque corresponds to a reduction in heart-attack risk (New York Times, 11/5). Esperion officials said that the company is planning a larger clinical trial involving 1,500 to 2,000 patients, USA Today reports (USA Today, 11/5). The Journal reports that Pfizer "appears to have the first claim" on forming a joint venture with Esperion to develop ApoA-1 because recently acquired Pharmacia, which developed a process to manufacture the protein in the early 1990s, retained the right of first refusal for any co-development or marketing venture. According to the Journal, Newton said that he intends to present a package of ApoA-1 data to Pfizer early next year, after which Pfizer will have 90 days to decide whether to pursue a co-development or marketing venture. Newton said that other companies are interested if Pfizer declines, the Journal reports (Wall Street Journal, 11/5). The study is available online. The accompanying editorial is available online.
The following broadcast programs reported on the study:
- ABCNews' "World News Tonight": The segment includes comments from Nissen and Rader (McKenzie, "World News Tonight," ABCNews, 11/4). The full transcript of the segment is available online.
- NBC's "Nightly News": The segment includes comments from Nissen (Bazell, "Nightly News," NBC, 11/4). The full segment is available online in Windows Media.
- NPR's "Morning Edition": The segment includes comments from Nissen, Rader and P.K. Shaw of Cedars-Sinai Medical Center (Knox, "Morning Edition," NPR, 11/5). The full segment is available online in RealPlayer.