University of Copenhagen & Copenhagen University Hospital Central role of apoCIII
Anne Tybjærg-Hansen MD DMSc Copenhagen University Hospital and Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
ISA Amsterdam 250515 Disclosures Anne Tybjærg-Hansen Professor of Clinical Biochemistry and Translational Molecular Cardiology
Consultancies and honoraria Eli Lilly and LGC Genomics Agenda apoCIII
•History •Physiology •Genetics suggest reduced risk of ischemic heart disease •Genetics suggest a new drug target •Genetics suggest target patients History – ApoCIII: 46 years old and even more interesting
Adapted from Ginsberg and Brown ATVB 2011 ApoCIII, a component of VLDL and an inhibitor of lipoprotein lipase ApoCIII, alignment and complete amino acid sequence APOC3 gene ApoCIII inhibits lipoprotein remnant uptake by the liver Studies in mice Physiology Adapted from Gaudet et al. NEJM 2014 ApoCIII
Ooi E et al. Clin Sci 2008;114:61124. Sacks F et al. Circulation 2000 Clinical use Clinical use Alternative
HDL HDL cholesterol Apo A1
LDL LDL cholesterol ApoB or Remnants non-HDL Remnant or cholesterol Triglycerides VLDL cholesterol
Triglycerides Cholesterol Plasma Intima
LDL LDL
Remnants Remnants
LPL LPL FFA + Monoacylglycerol Macrophage
Inflammation
Cholesterol Chylomicron
Triglycerides Foam cells Nordestgaard & Varbo, Lancet 2014; 384: 626-635 ApoCIII, direct proatherogenic role?
•Increased binding to proteoglycans
•Increases monocyte binding to cultured endothelial cells via stimulation of VCAM-1 Genetics suggest reduced risk of ischemic cardiovascular disease Department of Clinical Biochemistry, Rigshospitalet
Chromosome 11q23 (metaphase)
25 kilobasepairs 5’ APOA1 APOA4 APOA5 3’
3’ APOC3 5’
og ”Enhedens Department of Clinical Biochemistry, Rigshospitalet APOC3 Exon 1 Exon 3 untranslated 5’ 3’
Promoter Exon 2 Exon 4
Pre-protein: 99 amino acids
20 amino acid signal peptide
Mature protein: 79 amino acids
og ”Enhedens
R19X HAPI Study Amish Family Calcification Study
Anders Berg APOC3 Jørgensen MD PhD No. of No. of Theoretically Observed Triglycerides P-value participants events predicted risk risk Ischemic vascular disease
Any mutation Wildtype 75,465 10,770
P = 2x10-54 P = 0.007 All heterozygotes 260 27 - 44% - 41% Ischemic heart disease
Any mutation Wildtype 75,465 7,537 P = 2x10-54 P = 0.04 All heterozygotes 260 20
0 1 2 0.5 0.75 1 0.5 0.75 1 Triglycerides Hazard ratio Hazard ratio (mmol/L) (95% CI) (95% CI) Ischemic vascular disease
N alleles N total N events Risk estimate
APOC3 0 75,465 10,770 Jørgensen et al 1 - 44% 260 27 NEJM 2014 0.59
APOC3 0 110,472 33,889 TG and HDL 1 - 39% 498 113 Working Group 0.60 NEJM 2014 0 1 2 0.0 0.5 1.0 Triglycerides, mmol/L Hazard ratio (95% CI)
PCSK9 0 64,492 10,665 CGPS & 1 - 12% 1,697 250 CCHS 0.90
0 1 2 3 4 0.0 0.5 1.0 LDL cholesterol, mmol/L Hazard ratio (95% CI)
Nordestgaard & Varbo, Lancet 2014; 384: 626-635 Plasma Intima
LDL LDL
Remnants Remnants
LPL LPL FFA + Monoacylglycerol Macrophage
Inflammation
Cholesterol Chylomicron
Triglycerides Foam cells Nordestgaard & Varbo, Lancet 2014; 384: 626-635
Mendelian randomization hypotheses
established but causal? Biomarker Disease Risk 1
2 3 effect size? statistical power? pleiotropic effects?
Genotype Department of Clinical Biochemistry, Rigshospitalet Jørgensen AB et al. NEJM 2014 APOC3 No. of Mean + SE Mean + SE Mean + SE participants på -54 -29 Any mutation P = 2x10 P = 2x10 P = 0.06 Wildtype 75,465 All heterozygotes 260 -44% 24% -3%
-9 -5 R19X P = 3x10 P = 3x10 P = 0.35 Wildtype 75,692 Heterozygotes 33 -48% 26% 7%
IVS2+1G>A -43 -25 P = 4x10 P = 2x10 P = 0.01 Wildtype 75,516 Heterozygotes 209 -44% 24% -5%
A43T -5 P = 3x10 P = 0.13 P = 0.83 Wildtype 75,707 Heterozygotes 18 -47% 15% 2%
0 1 2 0 1 2 0 1 2 3 4 Triglycerides HDL cholesterol LDL cholesterol Enhedens (mmol/L) (mmol/L) (mmol/L) APOC3 and statin treatment
N Mean (+SE) (%) P Mean (+SE) (%) P
Corrected for statin use
Noncarriers 75,465
All heterozygotes 260 -43% 5x10-49 -4% 0.008
Excluding statin users
Noncarriers 68,419
All heterozygotes 244 -44% 2x10-49 -3% 0.02
0.0 0.5 1.0 0 1 2 3 4 Remnant cholesterol LDL cholesterol
Genetics suggest a new drug target Intermediate phenotype Disease Risk Undesirable effects? 1 2 3
Genotype Summary: Loss-of-function variants in APOC3 •43% reduction in calculated remnant cholesterol
•41% reduction in risk of ischemic heart disease
•Not explained by reduction in LDL cholesterol
•Suggests that APOC3 is a relevant drug target Department of Clinical Biochemistry, Rigshospitalet
2013;12:1479-90
Objective:To test the hypothesis that selective inhibition of apoCIII with antisense drugs in preclinical models and in healthy volunteers would reduce plasma apoCIII and triglyceride levels. (human apoCIII ASO ISIS 304801).
og ”Enhedens Administration of ISIS 304801 to healthy human volunteers produced dose- and time-dependent reductions in apolipoprotein C-III (apoC-III) and triglycerides levels.
Mark J. Graham et al. Circulation Research. 2013;112:1479-1490 Copyright © American Heart Association, Inc. All rights reserved. Administration of ISIS 304801 to healthy human volunteers produced dose- and time- dependent reductions in apolipoprotein C-III (apoC-III) and triglycerides levels.
Graham MJ et al. Circ Res 2013 Genetics suggest target patients N Engl J Med Volume 371(23):2200-2206 December 4, 2014
Genetic disorder characterized by severe hypertriglyceridemia and recurrent pancreatitis due to a deficiency in lipoprotein lipase. Lack of efficient therapies except extreme fat restriction or LPL gene replacement. Study overview •3 patients homozygous or compound heterozygous for severe loss-of-function mutations in LPL (triglycerides 16-24 mmol/L; P207L or G188E)
•ISIS 304801 ASO 300mg once weekly as s.c. injection for 13 weeks Effect of ISIS 304801 ASO 300mg once weekly as s.c. injection for 13 weeks
Gaudet D et al. N Engl J Med 2014;371:2200-2206 Plasma triglyceride metabolism
and the role of apoCIII.
Gaudet D et al. N Engl J Med 2014;371:2200-2206 Summary
Inhibition of ApoCIII had a profound and clinically relevant effect on triglyceride levels through a mechanism that is independent of lipoprotein lipase ApoCIII: 46 years old and even more interesting
Adapted from Ginsberg and Brown ATVB 2011 EAS Innsbruck 2016
Rare mutations in APOC3 and plasma levels of triglycerides.
The TG and HDL Working Group of the Exome Sequencing Project, National Heart, Lung, and Blood Institute. N Engl J Med 2014;371:22-31 Association of four APOC3 mutations with plasma lipid levels in replication studies.
The TG and HDL Working Group of the Exome Sequencing Project, National Heart, Lung, and Blood Institute. N Engl J Med 2014;371:22-31 Amish Family Calcification Study National Health and Nutrition Examination Surveys
Crawford et al. Circ Cardiovasc Genet 2014 NHANES
Crawford et al. Circ Cardiovasc Genet 2014 TwinsUK and Avon Longitudinal Study of Parents and Children
Timpson et al. Nature Commun 2014 Can the reduction in risk of CHD in the APOC3 mutant carriers be explained by the reduction in LDL cholesterol levels?
Could the contribution of LDL cholesterol be masked by statin treatment? Characteristics of APOC3 heterozygotes