"Amgen Incs experimental drug AMG reduced levels of bad cholesterol by as much as  percent in combination with statin drugs in patients genetically predisposed to high cholesterol according to data from a midstage trial presented on Monday.  The new drug given by injection every four weeks is part of a promising new class of biotech medicines known as PCSK inhibitors designed to target a protein that prevents the body from removing artery blocking LDL cholesterol from the bloodstream.  Statins such as Pfizer Incs Lipitor and AstraZenecas Crestor work by preventing the liver from making cholesterol.  Sponsored The Phase II trial found that after  weeks patients treated with a low dose of AMG had a  percent reduction in LDL while those given a higher dose had a drop of  percent. Patients treated with a placebo saw a  percent increase in LDL cholesterol.  The trial presented here at the annual scientific meeting of the American Heart Association included  patients with heterozygous familial hypercholesterolemia in which a defective gene inherited from one parent impairs the ability to properly metabolize LDL. The disorder is estimated to affect about one in  people and causes extremely high cholesterol.  The most common side effects seen in the trial were injectionsite reactions coldlike symptoms and headache.  AMG along with other PCSK inhibitors being developed by companies like Pfizer Regeneron Pharmaceuticals Inc in partnership with Sanofi and Roche is a manmade antibody."