An experimental biologic drug called REGN727 may help lower levels of LDL ("bad") cholesterol when a statin drug isn't enough, researchers report.

In a new study, REGN727 (which does not have a brand name yet) cut LDL cholesterol by up to 72% when given in addition to the statin Lipitor.

That study, presented at the American College of Cardiology's annual meeting, included about 180 people with LDL cholesterol levels of at least 100 mg/dL. For 12 weeks, they took Lipitor and got injections of REGN727 or a placebo.

In people who got 50 milligrams of the drug injected once every two weeks, LDL levels dropped by 40%. And in people who got 100 milligrams every two weeks, LDL levels fell by 64%. The most effective dose was 150 milligrams every two weeks, which lowered LDL by 72%.

In contrast, LDL levels dropped only 5% in people who got the placebo.

The researchers also tested two once-monthly doses of the drug, but they didn't work as well as the every-two-weeks injections, says study head James McKenney, PharmD, chief executive officer of National Clinical Research in Richmond, Va.

"This is a 'wow' study," says Rick Nishimura, MD, a heart specialist at the Mayo Clinic, who was head of the committee that chose which studies to highlight at the meeting. "It takes us to a whole new level of cholesterol control and could be a game changer in the future," he tells WebMD. Nishimura was not involved with the study.

Cholesterol 101: What Your Levels Mean
How It Works

The new drug works differently than statins do. It inhibits a protein called PCSK9. This, in turn, clears LDL cholesterol from the bloodstream.

Statin drugs work in a different way to remove LDL cholesterol from the bloodstream. While credited with making a substantial dent in heart disease, they don’t help everyone.

About 1 in 3 people with high LDL levels is resistant to statins or does not get enough benefit, leaving them at risk for heart attacks if they don't get additional treatment, McKenney says.

In the new study, REGN727 was generally safe, with mild infections and redness and soreness where the injection was given being the most common side effects. Serious side effects occurred in one person on placebo and in three people on the new drug, including one case of severe rash accompanied by diarrhea. Six people taking the drug stopped treatment due to side effects.

Another anti-PCSK9 drug -- currently called AMG 145 -- is also in development and, in an early study, lowered LDL levels when given in addition to a statin. At the meeting, Amgen presented findings from an earlier stage study of 51 people showing monthly injections of AMG 145 substantially lowered LDL when given on top of statins.
More Research Needed

Both studies are too small and too short to draw any conclusions about the drugs' safety, Raymond Gibbons, MD, of the Mayo Clinic in Rochester, Minn., and a past president of the American Heart Association, tells WebMD.

REGN727 and AMG 145 are both scheduled for larger, longer studies.

The big question is whether the gains in LDL cholesterol will translate into fewer heart attacks, strokes, and deaths, Gibbons says.

It's too early to know how much the new drugs will cost, but biologic drugs are often expensive

This REGN727 study was funded by Sanofi U.S. and Regeneron Pharmaceuticals, which make the drug. McKenney's company has received research funding from the companies. The AMG 145 study was presented by Amgen, the drug's maker.