In a surprising setback, a big federal study testing prescription-strength niacin as an add-on to cholesterol-lowering statins to prevent heart disease was stopped early because the niacin didn't work.
Plus, more patients taking the drug Niaspan had strokes than those who got a placebo. That potential safety issue was another factor in the decision to halt the study 18 months early, doctors involved with the research said in a media conference call Thursday.
Niacin is the most effective treatment for raising HDL, or good cholesterol. And the study aimed to find out if raising HDL and lowering triglycerides (another consequence of niacin treatment) in addition to using a statin to control LDL, or bad cholesterol, would lead to better outcomes for patients.
The answer: Niaspan didn't reduce the risk of cardiovascular events, including heart attacks and strokes. There were 5.6 such events per year for the group that got placebo — compared with 5.8 per year for those who got Niaspan.
All of the more than 3,400 patients in the study took simvastatin, the cholesterol-lowering medicine sold under the brand-name Zocor. Some also got Zetia, another cholesterol-reducer.
The federally funded trial, called AIM-HIGH, was stopped because a scheduled review by an independent safety committee in April concluded the chances that the trial, started in early 2006, would ever show the expected benefit from niacin was less than 1 in 10,000. There was also that small but significant increase in stroke.
The results deal a blow to the so-called HDL hypothesis, which holds that raising good cholesterol should lower risk of heart disease. Epidemiological studies have suggested that's the case, but this test didn't bear it out.
Dr. William Boden, one of the lead investigators on the study, conceded the researchers were unable to show any additional benefit from raising HDL in patients whose bad cholesterol was controlled so well. Still, he didn't rule out the possibility of a positive HDL effect for different types of patients.
The Food and Drug Administration recommended no changes, for now, in the instructions or use of Niaspan. But the agency will analyze the data further.
MICHELE NORRIS, Host:
Good to have you here, Scott.
SCOTT HENSLEY: Hi.
NORRIS: First of all, tell us what the theory behind the study was.
HENSLEY: It has been known for decades that people with higher HDL, the good cholesterol, all other things being equal, have a lower risk of heart attacks; it was first seen in people in Japan who had a genetically higher HDL. And this study was one that looked at: Could you get the same sort of effect by raising the HDL with a drug? And it was expected that it would show that, and it didn't.
NORRIS: And why didn't it happen?
HENSLEY: There was no change in the heart attack risk for people in the study.
NORRIS: Now the drug that we're talking about has been on the market for quite some time, and there are a good number of people taking this drug. What are they supposed to do now that its effects are called into question?
HENSLEY: If you're concerned about it, talk with your doctors, but right now, the data are fairly fresh. They're going to look at them some more, but there's no reason to change practice now.
NORRIS: Who conducted this study and why?
HENSLEY: And the expectation was that by adding this drug that raises the HDL to the combination for the people, it would help them, and it did not.
NORRIS: In looking at the reaction to this today, it appears that this study is causing an overall re-thinking of how to prevent heart attacks. Is that an accurate reading of this?
HENSLEY: I think so because the drug industry and doctors have done such a good job at hammering into us lower your bad cholesterol and improve your chances of avoiding a heart attack or a repeat heart attack or stroke, something like that.
HDL: How can we lower the risk even more? And HDL was thought to be the logical way to do that.
NORRIS: Any early indication about how the makers of Niaspan will respond to this? And what does this mean for other drugs that are in the pipeline that are similar to this?
HENSLEY: But I think what this study will emphasize is that just changing a number of the kind of fat that's in someone's blood is not really going to be enough. Makers of new drugs to raise HDL will have to show beyond any doubt that the drugs actually help patients.
NORRIS: Scott Hensley edits our health blog. It's called "Shots." Scott, thank you very much for coming in.
HENSLEY: My pleasure. Transcript provided by NPR, Copyright NPR.