This multicentre , randomised , double-blind , placebo-controlled trial was undertaken at 39 sites ( most of which were specialised lipid clinics , mainly attached to academic institutions ) in Australia , Asia , Europe , New Zealand , North America , and South Africa between Feb 7 and Dec 19 , 2013.331 eligible patients ( 18-80 years of age ) , who met clinical criteria for heterozygous familial hypercholesterolaemia and were on stable lipid-lowering therapy for at least 4 weeks , with a fasting LDL cholesterol concentration of 26 mmol/L or higher , were randomly allocated in a 2:2:1:1 ratio to receive subcutaneous evolocumab 140 mg every 2 weeks , evolocumab 420 mg monthly , or subcutaneous placebo every 2 weeks or monthly for 12 weeks .