The first large studies of the drugs were presented at an American College of Cardiology conference in Washington.
Several companies are developing these drugs, aimed at millions worldwide who have high LDL or "bad" cholesterol - a major risk for heart disease.
Three studies of Amgen's version of these drugs, called evolocumab, found it lowered LDL by 55 to 66% from baseline levels compared with others who took a fake drug.
Doctors now want evidence that the way these drugs lower cholesterol also will lead to fewer heart attacks and deaths.
New studies are under way to test this, but Amgen said it would seek US government approval for its drug this year based on cholesterol-lowering alone.