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 Triglycerides LDL Remnants LDL cholesterol Remnant or VLDL cholesterol ApoB or non-hdl cholesterol Triglycerides Cholesterol
Plasma Intima LDL LDL Remnants Remnants LPL FFA + Monoacylglycerol Inflammation LPL Macrophage 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) 5 APOA1 APOA4 25 kilobasepairs APOA5 3 3 APOC3 5
Department of Clinical Biochemistry, Rigshospitalet Exon 1 untranslated APOC3 Exon 3 5 3 Promoter Exon 2 Exon 4 Pre-protein: 99 amino acids 20 amino acid signal peptide Mature protein: 79 amino acids
R19X HAPI Study
Amish Family Calcification Study
Anders Berg Jørgensen MD PhD APOC3 No. of participants No. of events Triglycerides Theoretically predicted risk Observed risk P-value Ischemic vascular disease Any mutation Wildtype 75,465 10,770 All heterozygotes 260 27 P = 2x10-54 P = 0.007-44% - 41% Ischemic heart disease Any mutation Wildtype All heterozygotes 75,465 260 7,537 20 P = 2x10-54 P = 0.04 0 1 2 Triglycerides (mmol/l) 0.5 0.75 1 Hazard ratio (95% CI) 0.5 0.75 1 Hazard ratio (95% CI)
Nordestgaard & Varbo, Lancet 2014; 384: APOC3 Jørgensen et al NEJM 2014 APOC3 TG and HDL Working Group NEJM 2014 0 1 0 1 Ischemic vascular disease N alleles N total N events Risk estimate - 44% - 39% 0 1 2 Triglycerides, mmol/l 75,465 10,770 260 27 0.59 110,472 33,889 498 113 0.60 0.0 0.5 1.0 Hazard ratio (95% CI) PCSK9 CGPS & CCHS 0 1-12% 64,492 10,665 1,697 250 0.90 0 1 2 3 4 LDL cholesterol, mmol/l 0.0 0.5 1.0 Hazard ratio (95% CI)
Plasma Intima LDL LDL Remnants Remnants LPL FFA + Monoacylglycerol Inflammation LPL Macrophage Cholesterol Chylomicron Triglycerides Foam cells Nordestgaard & Varbo, Lancet 2014; 384: 626-635
Mendelian randomization hypotheses established but causal? Biomarker 1 Disease Risk effect size? pleiotropic effects? 2 3 Genotype statistical power?
Department of Clinical Biochemistry, Rigshospitalet Jørgensen AB et al. NEJM 2014 APOC3 Any mutation Wildtype No. of participants 75,465 Mean + SE P = 2x10-54 Mean + SE P = 2x10-29 Mean + SE P = 0.06 All heterozygotes 260-44% 24% -3% R19X Wildtype 75,692 P = 3x10-9 P = 3x10-5 P = 0.35 Heterozygotes 33-48% 26% 7% IVS2+1G>A Wildtype 75,516 P = 4x10-43 P = 2x10-25 P = 0.01 Heterozygotes 209-44% 24% -5% A43T Wildtype 75,707 P = 3x10-5 P = 0.13 P = 0.83 Heterozygotes 18-47% 15% 2% 0 1 2 0 1 2 0 1 2 3 4 Triglycerides (mmol/l) HDL cholesterol (mmol/l) LDL cholesterol (mmol/l)
APOC3 and statin treatment Corrected for statin use N Mean (+SE) (%) P Mean (+SE) (%) P 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 Remnant cholesterol 0 1 2 3 4 LDL cholesterol
Genetics suggest a new drug target
Intermediate phenotype 1 2 3 Disease Risk Undesirable effects? 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).
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 timedependent 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