The agency will likely follow the advisory committee’s advice when it decides whether to approve the drug, alirocumab (Praluent) from Sanofi SA and Regeneron Pharmaceuticals Inc., for patients later this summer. On Wednesday, the advisory committee will discuss a second drug in the same class, evolocumab (Repatha) from Amgen Inc.

The drugs represent the most important new class of cholesterol-lowering medications since the first statin was approved in 1987. Seven statins are available in the United States, including Zocor, Lipitor and Crestor.

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The new drugs are a “powerful new way of lowering the bad form of cholesterol, and that has profound implications in dealing with the burden of vascular disease,” which can lead to heart attacks and stroke, said Dr. Elliott Antman, president of the American Heart Association.

Although statins will continue to be a mainstay for the management of high levels of bad (LDL) cholesterol and reducing risk of heart attack and stroke, Antman said there are two groups of patients who could strongly benefit from having an alternative to statins.

One is the group that experiences severe side effects to statins, and as a result may stop taking them. The most common side effect is muscle pain and weakness, which is estimated to affect between 10% and 25% of users. In contrast, clinical trials of alirocumab and evolocumab did not find an increase in muscle pain among study participants taking these drugs for several months compared with those taking a placebo control.

The other group is people whose levels of LDL cholesterol still hover above the desirable range even after taking statins. Although a small subset of this group — about 1 in 500 of all people with high cholesterol — have a genetic predisposition (familial hypercholesterolemia) that could affect their response to statins, it is not clear why others do not get sufficient cholesterol-lowering benefit, Antman said.

“There is a tremendous unmet need” beyond statins, said Dr. Robert S. Rosenson, director of the Cardiometabolics Unit at the Icahn School of Medicine at Mount Sinai.

Patients who cannot tolerate, or do not respond adequately to, statins can take other medications but they are generally expensive and may not be that effective at reducing cholesterol, said Rosenson, who has been involved in trials of evolocumab and is on the international Data and Safety Monitoring Board for Sanofi-Regeneron Pharmaceuticals (which is sponsoring alirocumab).

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In a study of nearly 4,500 patients, including those who did not tolerate or respond to statins, 90% of patients who took evolocumab along with standard therapy had LDL levels in the optimal range after three months, compared with 26% in the group that took the standard therapy alone (which depending on the care center could include medications and exercise and diet regimens).

In this study, the rates of heart attacks, strokes and other cardiovascular disease were also lower (1%) in the evolocumab group compared with the standard therapy (2.2%). So far, clinical studies of alirocumab suggest it is similar in effectiveness to evolocumab. “Preliminarily, there appears to be no striking difference between the two,” Antman said.

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Although there has been some concern that the dramatic drop in LDL levels achieved with these drugs could actually be harmful, the concern has not panned out. “That is of course something that everybody has been watching, and I have been pleased with what I have seen to date,” Antman said. He added that alirocumab and evolocumab may lower LDL down to between 30 and 40 milligrams/deciliter. (The optimal range is below 100 milligrams/deciliter.)

The potency of these drugs comes from the fact that they block a protein in the body called PCSK9, and are thus called PCSK9 inhibitors. The result of this inhibition is that more molecules known as LDL receptors are available on the surface of cells in the liver to take up LDL, clearing this bad form of cholesterol from the body.

There have also been concerns that alirocumab and evolocumab, like statins, may induce short-term memory loss. The FDA warned statin users about this possibility in 2012.

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