CHICAGO Regeneron Corp's experimental drug alirocumab helped 10 times as many high-risk patients unable to tolerate widely-used statins get their "bad" LDL cholesterol down to target levels than Merck & Co's Zetia, according to data from a clinical trial presented on Monday.
Alirocumab, developed along with French drugmaker Sanofi, belongs to a new class of potent drugs that block a naturally occurring protein called PCSK9 that prevents the liver from removing LDL from the blood.
Patients in the 360-subject study, called Odyssey Alternative, on average had LDL levels above 190 and all were deemed statin intolerant due to muscle and skeletal side effects when taking the popular medicines.
After 24 weeks of treatment, alirocumab lowered LDL by 45 percent compared with 14.6 percent for Zetia (ezetimibe).
Importantly, 42 percent of alirocumab patients got LDL down to target levels versus 4 percent for Zetia. That rose to 51 percent versus 6 when excluding those who didn't complete 24 weeks of treatment. Target goals were for LDL under 70 for very high-risk patients and under 100 for high-risk patients.
"It's a more potent and more effective lipid lowering drug, getting patients to goal by a 10-fold higher amount. It just blows (Zetia) away," said Dr. Patrick Moriarty, the study's lead investigator, who presented the results at the American Heart Association scientific meeting in Chicago.
Zetia is used to lower LDL in patients who cannot take highly effective statins, such as Pfizer's Lipitor. They are among the most likely candidates for PCSK9 inhibitors once approved.
Curiously, during a four-week preliminary period when all patients were just getting a placebo, 47 dropped out, including 25 complaining of muscular side effects.
During the actual treatment period, 18.3 percent of alirocumab patients, 25 percent on Zetia and 25.4 percent who were given Lipitor in a third group discontinued treatment.
In an ongoing extension of the trial, with patients aware of what they were taking, the alirocumab discontinuation rate from muscular side effects fell dramatically.
That most patients given Lipitor stayed on therapy calls into question their actual statin intolerance.
"This shows you the complexity of diagnosing statin intolerance," Moriarty said. "This population is not simple."
Regeneron and Sanofi expect to apply for U.S. and European approval this year. But a patent infringement lawsuit filed by Amgen over its rival drug could complicate that.
(Reporting by Bill Berkrot; Editing by Nick Zieminski)