Known as REGN727/SAR236553, the drug is a monoclonal antibody, a type of biologic. A biologic is created through a biological process instead of chemically synthesized.
Stein compared the effects of taking Lipitor (atorvastatin) along with either injections of the new monoclonal antibody or a placebo injection. He tested it in patients who still had high LDL levels despite taking a starting dose of Lipitor for at least seven weeks.
The study was funded by Sanofi and Regeneron Pharmaceuticals, which make the new biologic. It is published in the New England Journal of Medicine.
Although the results look promising, long-term studies are still needed, says Raymond J. Gibbons, MD. Gibbons is professor of medicine at Mayo Clinic, in Rochester, Minn. He was not involved in the study.
"About 10% to 20% of patients cannot tolerate statins or high enough doses to get [their cholesterol] under control," he says.
The new drug inhibits a protein called PCSK9. In the process, it allows for the removal of LDL from the blood.
Stein's team studied the new drug in 92 patients. Their average age was in the mid- to late-50s. All had LDL levels above 100 even after taking 10 milligrams of Lipitor for at least seven weeks.
He assigned patients to one of three groups for eight weeks:
- 80 milligrams of Lipitor daily, plus injections of the new drug every two weeks
- 10 milligrams of Lipitor a day, plus injections of the new drug every two weeks
- 80 milligrams of Lipitor daily, plus placebo injections every two weeks.
The researchers followed the patients for eight more weeks.
All those who got the new biologic lowered their cholesterol below 100.
But only 52% of those who got 80 milligrams of Lipitor but placebo injections lowered their LDL below 100.
"More than nine out of 10 of those who got the new drug lowered their LDL to below 70, regardless of whether the statin dose was 10 or 80 milligrams," Stein says.
Only 17% of those who got the higher dose of Lipitor and placebo injections reduced their LDL levels below 70.
However, Stein says, the study was fairly short term, "especially for drugs that will likely be taken life-long." And larger studies are needed.
He says it is too early to estimate the cost of the new drug.
He reports consulting fees from Amgen, Adnexus Therapeutics, Genentech, Regeneron, and Sanofi related to PCSK9 inhibitors. His institution has received research funds directly related to PCSK9 clinical trials and lab analysis from Alnylam, Amgen, BMS, Genentech, Sanofi, and Regeneron.
Looking to the Future
Long-term data are needed and critical for further understanding, Gibbons says.
The need to inject the drug may not appeal to some patients, he says. "The inconvenience would be a barrier to many patients, particularly to those who don't have their own transportation."
Researchers need to examine whether the new drug results in fewer heart attacks and strokes.
Sanofi and Regeneron Pharmaceuticals are recruiting people for additional studies.
Amgen and other companies are also developing PCSK9 protein inhibitor drugs.