title: Efficacy, safety, and tolerability of a monoclonal antibody to proprotein convertase subtilisin/kexin type 9 as monotherapy in patients with hypercholesterolaemia (MENDEL): a randomised, double-blind, placebo-controlled, phase 2 study.
abstract: BACKGROUND
  Proprotein convertase subtilisin/kexin type 9 (PCSK9) increases serum LDL-cholesterol (LDL-C) concentrations. We assessed the effects of AMG 145, a human monoclonal antibody against PCSK9, in patients with hypercholesterolaemia in the absence of concurrent lipid-lowering treatment.
  
  
  METHODS
  In a phase 2 trial done at 52 centres in Europe, the USA, Canada, and Australia, patients (aged 18-75 years) with serum LDL-C concentrations of 2·6 mmol/L or greater but less than 4·9 mmol/L were randomly assigned equally through an interactive voice response system to subcutaneous injections of AMG 145 70 mg, 105 mg, or 140 mg, or placebo every 2 weeks; subcutaneous AMG 145 280 mg, 350 mg, or 420 mg or placebo every 4 weeks; or oral ezetimibe 10 mg/day. The primary endpoint was percentage change from baseline in LDL-C concentration at week 12. Analysis was by modified intention to treat. Study personnel and patients were masked to treatment assignment of AMG 145 or placebo. Ezetimibe assignment was open label. This trial is registered with ClinicalTrials.gov, number NCT01375777.
  
  
  RESULTS
  406 patients were assigned to AMG 145 70 mg (n=45), 105 mg (n=46), or 140 mg (n=45) every 2 weeks; AMG 145 280 mg (n=45), 350 mg (n=45), or 420 mg (n=45) every 4 weeks; placebo every 2 weeks (n=45) or every 4 weeks (n=45); or ezetimibe (n=45). AMG 145 significantly reduced LDL-C concentrations in all dose groups (mean baseline LDL-C concentration 3·7 mmol/L [SD 0·6]; changes from baseline with every 2 weeks AMG 145 70 mg -41·0% [95% CI -46·2 to -35·8]; 105 mg -43·9% [-49·0 to -38·7]; 140 mg -50·9% [-56·2 to -45·7]; every 4 weeks AMG 145 280 mg -39·0% [-44·1 to -34·0]; 350 mg -43·2% [-48·3 to -38·1]; 420 mg -48·0% [-53·1 to -42·9]; placebo every 2 weeks -3·7% [-9·0 to 1·6]; placebo every 4 weeks 4·5% [-0·7 to 9·8]; and ezetimibe -14·7% [-18·6 to -10·8]; p<0·0001 for all doses vs placebo or ezetimibe). Treatment-emergent adverse events occurred in 136 (50%) of 271 patients in the AMG 145 groups, 41 (46%) of 90 patients in the placebo groups, and 26 (58%) of 45 patients in the ezetimibe group; no deaths or serious treatment-related adverse events were reported.
  
  
  CONCLUSIONS
  The results of our study support the further assessment of AMG 145 in long-term studies with larger and more diverse populations including patients with documented statin intolerance.
  
  
  BACKGROUND
  Amgen.
authors.affiliation: Jacksonville Center for Clinical Research, FL, USA. mkoren@encoredocs.com
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Koren
authors.forename: Rob
authors.initials: R
authors.lastname: Scott
authors.forename: Jae B
authors.initials: JB
authors.lastname: Kim
authors.forename: Beat
authors.initials: B
authors.lastname: Knusel
authors.forename: Thomas
authors.initials: T
authors.lastname: Liu
authors.forename: Lei
authors.initials: L
authors.lastname: Lei
authors.forename: Michael
authors.initials: M
authors.lastname: Bolognese
authors.forename: Scott M
authors.initials: SM
authors.lastname: Wasserman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000924:Anticholesteremic Agents / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000188:drug therapy*; D007074:Immunoglobulin G / Q000276:immunology; D008297:Male; D008875:Middle Aged; D000071449:Proprotein Convertase 9; D043484:Proprotein Convertases / Q000037:antagonists & inhibitors* / Q000276:immunology; D012697:Serine Endopeptidases / Q000276:immunology; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000924:Anticholesteremic Agents; D007074:Immunoglobulin G; C472125:PCSK9 protein, human; D000071449:Proprotein Convertase 9; D043484:Proprotein Convertases; D012697:Serine Endopeptidases; C577155:evolocumab