Olezarsen, Acute Pancreatitis, and Familial Chylomicronemia Syndrome.

BACKGROUND: Familial chylomicronemia syndrome is a genetic disorder associated with severe hypertriglyceridemia and severe acute pancreatitis. Olezarsen reduces the plasma triglyceride level by reducing hepatic synthesis of apolipoprotein C-III. METHODS: In a phase 3, double-blind, placebo-controlled trial, we randomly assigned patients with genetically identified familial chylomicronemia syndrome to receive olezarsen at a dose of 80 mg or 50 mg or placebo subcutaneously every 4 weeks for 49 weeks. There were two primary end points: the difference between the 80-mg olezarsen group and the placebo group in the percent change in the fasting triglyceride level from baseline to 6 months, and (to be assessed if the first was significant) the difference between the 50-mg olezarsen group and the placebo group. Secondary end points included the mean percent change from baseline in the apolipoprotein C-III level and an independently adjudicated episode of acute pancreatitis. RESULTS: A total of 66 patients underwent randomization; 22 were assigned to the 80-mg olezarsen group, 21 to the 50-mg olezarsen group, and 23 to the placebo group. At baseline, the mean (±SD) triglyceride level among the patients was 2630±1315 mg per deciliter, and 71% had a history of acute pancreatitis within the previous 10 years. Triglyceride levels at 6 months were significantly reduced with the 80-mg dose of olezarsen as compared with placebo (-43.5 percentage points; 95% confidence interval [CI], -69.1 to -17.9; P<0.001) but not with the 50-mg dose (-22.4 percentage points; 95% CI, -47.2 to 2.5; P = 0.08). The difference in the mean percent change in the apolipoprotein C-III level from baseline to 6 months in the 80-mg group as compared with the placebo group was -73.7 percentage points (95% CI, -94.6 to -52.8) and between the 50-mg group as compared with the placebo group was -65.5 percentage points (95% CI, -82.6 to -48.3). By 53 weeks, 11 episodes of acute pancreatitis had occurred in the placebo group, and 1 episode had occurred in each olezarsen group (rate ratio [pooled olezarsen groups vs. placebo], 0.12; 95% CI, 0.02 to 0.66). Adverse events of moderate severity that were considered by a trial investigator at the site to be related to the trial drug or placebo occurred in 4 patients in the 80-mg olezarsen group. CONCLUSIONS: In patients with familial chylomicronemia syndrome, olezarsen may represent a new therapy to reduce plasma triglyceride levels. (Funded by Ionis Pharmaceuticals; Balance ClinicalTrials.gov number, NCT04568434.).

Sympathetic Neuronal Activation Triggers Myeloid Progenitor Proliferation and Differentiation.

There is a growing body of research on the neural control of immunity and inflammation. However, it is not known whether the nervous system can regulate the production of inflammatory myeloid cells from hematopoietic progenitor cells in disease conditions. Myeloid cell numbers in diabetic patients were strongly correlated with plasma concentrations of norepinephrine, suggesting the role of sympathetic neuronal activation in myeloid cell production. The spleens of diabetic patients and mice contained higher numbers of tyrosine hydroxylase (TH)-expressing leukocytes that produced catecholamines. Granulocyte macrophage progenitors (GMPs) expressed the ß2 adrenergic receptor, a target of catecholamines. Ablation of splenic sympathetic neuronal signaling using surgical, chemical, and genetic approaches diminished GMP proliferation and myeloid cell development. Finally, mice lacking TH-producing leukocytes had reduced GMP proliferation, resulting in diminished myelopoiesis. Taken together, our study demonstrates that catecholamines produced by leukocytes and sympathetic nerve termini promote GMP proliferation and myeloid cell development.

Major Facilitator Superfamily Domain Containing 5 Inhibition Reduces Lipoprotein(a) Uptake and Calcification in Valvular Heart Disease.

BACKGROUND: High circulating levels of Lp(a) (lipoprotein[a]) increase the risk of atherosclerosis and calcific aortic valve disease, affecting millions of patients worldwide. Although atherosclerosis is commonly treated with low-density lipoprotein-targeting therapies, these do not reduce Lp(a) or risk of calcific aortic valve disease, which has no available drug therapies. Targeting Lp(a) production and catabolism may provide therapeutic benefit, but little is known about Lp(a) cellular uptake. METHODS: Here, unbiased ligand-receptor capture mass spectrometry was used to identify MFSD5 (major facilitator superfamily domain containing 5) as a novel receptor/cofactor involved in Lp(a) uptake. RESULTS: Reducing MFSD5 expression by a computationally identified small molecule or small interfering RNA suppressed Lp(a) uptake and calcification in primary human valvular endothelial and interstitial cells. MFSD5 variants were associated with aortic stenosis (P=0.027 after multiple hypothesis testing) with evidence suggestive of an interaction with plasma Lp(a) levels. CONCLUSIONS: MFSD5 knockdown suppressing human valvular cell Lp(a) uptake and calcification, along with meta-analysis of MFSD5 variants associating with aortic stenosis, supports further preclinical assessment of MFSD5 in cardiovascular diseases, the leading cause of death worldwide.

Diacylglycerols and Lysophosphatidic Acid, Enriched on Lipoprotein(a), Contribute to Monocyte Inflammation.

BACKGROUND: Oxidized phospholipids play a key role in the atherogenic potential of lipoprotein(a) (Lp[a]); however, Lp(a) is a complex particle that warrants research into additional proinflammatory mediators. We hypothesized that additional Lp(a)-associated lipids contribute to the atherogenicity of Lp(a). METHODS: Untargeted lipidomics was performed on plasma and isolated lipoprotein fractions. The atherogenicity of the observed Lp(a)-associated lipids was tested ex vivo in primary human monocytes by RNA sequencing, ELISA, Western blot, and transendothelial migratory assays. Using immunofluorescence staining and single-cell RNA sequencing, the phenotype of macrophages was investigated in human atherosclerotic lesions. RESULTS: Compared with healthy individuals with low/normal Lp(a) levels (median, 7 mg/dL [18 nmol/L]; n=13), individuals with elevated Lp(a) levels (median, 87 mg/dL [218 nmol/L]; n=12) demonstrated an increase in lipid species, particularly diacylglycerols (DGs) and lysophosphatidic acid (LPA). DG and the LPA precursor lysophosphatidylcholine were enriched in the Lp(a) fraction. Ex vivo stimulation with DG(40:6) demonstrated a significant upregulation in proinflammatory pathways related to leukocyte migration, chemotaxis, NF-κB (nuclear factor kappa B) signaling, and cytokine production. Functional assessment showed a dose-dependent increase in the secretion of IL (interleukin)-6, IL-8, and IL-1ß after DG(40:6) and DG(38:4) stimulation, which was, in part, mediated via the NLRP3 (NOD [nucleotide-binding oligomerization domain]-like receptor family pyrin domain containing 3) inflammasome. Conversely, LPA-stimulated monocytes did not exhibit an inflammatory phenotype. Furthermore, activation of monocytes by DGs and LPA increased their transendothelial migratory capacity. Human atherosclerotic plaques from patients with high Lp(a) levels demonstrated colocalization of Lp(a) with M1 macrophages, and an enrichment of CD68+IL-18+TLR4+ (toll-like receptor) TREM2+ (triggering receptor expressed on myeloid cells) resident macrophages and CD68+CASP1+ (caspase) IL-1B+SELL+ (selectin L) inflammatory macrophages compared with patients with low Lp(a). Finally, potent Lp(a)-lowering treatment (pelacarsen) resulted in a reduction in specific circulating DG lipid subspecies in patients with cardiovascular disease with elevated Lp(a) levels (median, 82 mg/dL [205 nmol/L]). CONCLUSIONS: Lp(a)-associated DGs and LPA have a potential role in Lp(a)-induced monocyte inflammation by increasing cytokine secretion and monocyte transendothelial migration. This DG-induced inflammation is, in part, NLRP3 inflammasome dependent.

Efficacy and safety of garadacimab, a factor XIIa inhibitor for hereditary angioedema prevention (VANGUARD): a global, multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Hereditary angioedema is a rare and potentially life-threatening genetic disease that is associated with kallikrein-kinin system dysregulation. Garadacimab (CSL312), a novel, fully-human monoclonal antibody that inhibits activated factor XII (FXIIa), is being studied for the prevention of hereditary angioedema attacks. The aim of this study was to evaluate the efficacy and safety of once-monthly subcutaneous administrations of garadacimab as prophylaxis for hereditary angioedema. METHODS: VANGUARD was a pivotal, multicentre, randomised, double-blind, placebo-controlled, phase 3 trial that recruited patients (aged ≥12 years) with type I or type II hereditary angioedema across seven countries (Canada, Germany, Hungary, Israel, Japan, the Netherlands, and the USA). Eligible patients were randomly assigned (3:2) to receive garadacimab or placebo for 6 months (182 days) by an interactive response technology (IRT) system. Randomisation was stratified by age (≤17 years vs >17 years) and baseline attack rate (1 to <3 attacks per month vs ≥3 attacks per month) for the adult group. The randomisation list and code were kept by the IRT provider during the study, with no access by site staff and funding representatives. All patients and investigational site staff, and representatives from the funder (or their delegates) with direct interaction with the study sites or patients, were masked to treatment assignment in a double-blind fashion. Randomly assigned patients received a 400-mg loading dose of subcutaneous garadacimab as two 200-mg injections or volume-matched placebo on day 1 of the treatment period, followed by five additional self-administered (or caregiver-administered) monthly doses of 200-mg subcutaneous garadacimab or volume-matched placebo. The primary endpoint was the investigator-assessed time-normalised number of hereditary angioedema attacks (number of hereditary angioedema attacks per month) during the 6-month treatment period (day 1 to day 182). Safety was evaluated in patients who received at least one dose of garadacimab or placebo. The study is registered with the EU Clinical Trials Register, 2020-000570-25 and ClinicalTrials.gov, NCT04656418. FINDINGS: Between Jan 27, 2021, and June 7, 2022, we screened 80 patients, 76 of whom were eligible to enter the run-in period of the study. Of 65 eligible patients with type I or type II hereditary angioedema, 39 were randomly assigned to garadacimab and 26 to placebo. One patient was randomly assigned in error and did not enter the treatment period (no dose of study drug received), resulting in 39 patients assigned to garadacimab and 25 patients assigned to placebo being included. 38 (59%) of 64 participants were female and 26 (41%) were male. 55 (86%) of 64 participants were White, six (9%) were Asian (Japanese), one (2%) was Black or African American, one (2%) was Native Hawaiian or Other Pacific Islander, and one (2%) was listed as other. During the 6-month treatment period (day 1 to day 182), the mean number of investigator-confirmed hereditary angioedema attacks per month was significantly lower in the garadacimab group (0·27, 95% CI 0·05 to 0·49) than in the placebo group (2·01, 1·44 to 2·57; p<0·0001), corresponding to a percentage difference in means of -87% (95% CI -96 to -58; p<0·0001). The median number of hereditary angioedema attacks per month was 0 (IQR 0·00-0·31) for garadacimab and 1·35 (1·00-3·20) for placebo. The most common treatment-emergent adverse events were upper-respiratory tract infections, nasopharyngitis, and headaches. FXIIa inhibition was not associated with an increased risk of bleeding or thromboembolic events. INTERPRETATION: Monthly garadacimab administration significantly reduced hereditary angioedema attacks in patients aged 12 years and older compared with placebo and had a favourable safety profile. Our results support the use of garadacimab as a potential prophylactic therapy for the treatment of hereditary angioedema in adolescents and adults. FUNDING: CSL Behring.

Breaking the chains of lipoprotein lipase deficiency: A pediatric perspective on the efficacy and safety of Volanesorsen.

RATIONALE: Lipoprotein lipase (LPL) deficiency, a rare inherited metabolic disorder, is characterized by high triglyceride (TG) levels and life-threatening acute pancreatitis. Current treatment for pediatric patients involves a lifelong severely fat-restricted diet, posing adherence challenges. Volanesorsen, an EMA-approved RNA therapy for adults, effectively reduces TG levels by decreasing the production of apolipoprotein C-III. This 96-week observational open-label study explores Volanesorsen's safety and efficacy in a 13-year-old female with LPL deficiency. METHODS: The patient, with a history of severe TG elevations, 53 hospital admissions, and life-threatening recurrent pancreatitis despite dietary restrictions, received weekly subcutaneous Volanesorsen injections. We designed a protocol for this investigator-initiated study, primarily focusing on changes in fasting TG levels and hospital admissions. RESULTS: While the injections caused occasional pain and swelling, no other adverse events were observed. TG levels decreased during treatment, with more measurements below the pancreatitis risk threshold compared to pre-treatment. No hospital admissions occurred in the initial 14 months of treatment, contrasting with 21 admissions in the 96 weeks before. In the past 10 months, two pancreatitis episodes may have been linked to dietary noncompliance. Dietary restrictions were relaxed, increasing fat intake by 65% compared to baseline. While not fully reflected in the PedsQL, both parents and the patient narratively reported an improved quality of life. CONCLUSION: This study demonstrates, for the first time, that Volanesorsen is tolerated in a pediatric patient with severe LPL deficiency and effectively lowers TG levels, preventing life-threatening complications. This warrants consideration for expanded access in this population.

New Approaches for Targeting PCSK9: Small-Interfering Ribonucleic Acid and Genome Editing.

There is overwhelming clinical and genetic evidence supporting the concept that low-density-lipoprotein cholesterol should be as low as possible for as long as possible in patients at very high cardiovascular risk. Despite the wide availability of effective lipid-lowering therapies, the majority of patients still fail to reach guideline-based lipid goals. Advances in novel approaches targeting PCSK9 (proprotein convertase subtilisin/kexin type 9) through small-interfering RNA and genome editing hold the potential to bridge this gap, by offering long-acting alternatives, which may overcome adherence and other challenges in the current chronic care model. In this review, we discuss the history of targeting PCSK9 with the use of mRNA and small-interfering ribonucleic acid. We also shed light on targeting PCSK9 with genome editing, including discussion of the VERVE-101 clustered regularly interspaced short palindromic repeats-base editing medicine currently being evaluated in a clinical trial and others in development.

Peripheral Ischemia Imprints Epigenetic Changes in Hematopoietic Stem Cells to Propagate Inflammation and Atherosclerosis.

BACKGROUND: Peripheral ischemia caused by peripheral artery disease is associated with systemic inflammation, which may aggravate underlying comorbidities such as atherosclerosis and heart failure. However, the mechanisms of increased inflammation and inflammatory cell production in patients with peripheral artery disease remain poorly understood. METHODS: We used peripheral blood collected from patients with peripheral artery disease and performed hind limb ischemia (HI) in Apoe-/- mice fed a Western diet and C57BL/6J mice with a standard laboratory diet. Bulk and single-cell RNA sequencing analysis, whole-mount microscopy, and flow cytometry were performed to analyze hematopoietic stem and progenitor cell (HSPC) proliferation, differentiation, and relocation. RESULTS: We observed augmented numbers of leukocytes in the blood of patients with peripheral artery disease and Apoe-/- mice with HI. RNA sequencing and whole-mount imaging of the bone marrow revealed HSPC migration into the vascular niche from the osteoblastic niche and their exaggerated proliferation and differentiation. Single-cell RNA sequencing demonstrated alterations in the genes responsible for inflammation, myeloid cell mobilization, and HSPC differentiation after HI. Heightened inflammation in Apoe-/- mice after HI aggravated atherosclerosis. Surprisingly, bone marrow HSPCs expressed higher amounts of the receptors for IL (interleukin)-1 and IL-3 after HI. Concomitantly, the promoters of Il1r1 and Il3rb had augmented H3K4me3 and H3K27ac marks after HI. Genetic and pharmacological inhibition of these receptors resulted in suppressed HSPC proliferation, reduced leukocyte production, and ameliorated atherosclerosis. CONCLUSIONS: Our findings demonstrate increased inflammation, HSPC abundance in the vascular niches of the bone marrow, and elevated IL-3Rb and IL-1R1 (IL-1 receptor 1) expression in HSPC following HI. Furthermore, the IL-3Rb and IL-1R1 signaling plays a pivotal role in HSPC proliferation, leukocyte abundance, and atherosclerosis aggravation after HI.

Proteomics and lipidomics in atherosclerotic cardiovascular disease risk prediction.

Given the limited accuracy of clinically used risk scores such as the Systematic COronary Risk Evaluation 2 system and the Second Manifestations of ARTerial disease 2 risk scores, novel risk algorithms determining an individual's susceptibility of future incident or recurrent atherosclerotic cardiovascular disease (ASCVD) risk are urgently needed. Due to major improvements in assay techniques, multimarker proteomic and lipidomic panels hold the promise to be reliably assessed in a high-throughput routine. Novel machine learning-based approaches have facilitated the use of this high-dimensional data resulting from these analyses for ASCVD risk prediction. More than a dozen of large-scale retrospective studies using different sets of biomarkers and different statistical methods have consistently demonstrated the additive prognostic value of these panels over traditionally used clinical risk scores. Prospective studies are needed to determine the clinical utility of a biomarker panel in clinical ASCVD risk stratification. When combined with the genetic predisposition captured with polygenic risk scores and the actual ASCVD phenotype observed with coronary artery imaging, proteomics and lipidomics can advance understanding of the complex multifactorial causes underlying an individual's ASCVD risk.

2023 Update on European Atherosclerosis Society Consensus Statement on Homozygous Familial Hypercholesterolaemia: new treatments and clinical guidance.

This 2023 statement updates clinical guidance for homozygous familial hypercholesterolaemia (HoFH), explains the genetic complexity, and provides pragmatic recommendations to address inequities in HoFH care worldwide. Key strengths include updated criteria for the clinical diagnosis of HoFH and the recommendation to prioritize phenotypic features over genotype. Thus, a low-density lipoprotein cholesterol (LDL-C) >10 mmol/L (>400 mg/dL) is suggestive of HoFH and warrants further evaluation. The statement also provides state-of-the art discussion and guidance to clinicians for interpreting the results of genetic testing and for family planning and pregnancy. Therapeutic decisions are based on the LDL-C level. Combination LDL-C-lowering therapy-both pharmacologic intervention and lipoprotein apheresis (LA)-is foundational. Addition of novel, efficacious therapies (i.e. inhibitors of proprotein convertase subtilisin/kexin type 9, followed by evinacumab and/or lomitapide) offers potential to attain LDL-C goal or reduce the need for LA. To improve HoFH care around the world, the statement recommends the creation of national screening programmes, education to improve awareness, and management guidelines that account for the local realities of care, including access to specialist centres, treatments, and cost. This updated statement provides guidance that is crucial to early diagnosis, better care, and improved cardiovascular health for patients with HoFH worldwide.

Unexpected gaps in knowledge of familial hypercholesterolaemia among Dutch general practitioners.

BACKGROUND: Familial hypercholesterolaemia (FH) warrants early diagnosis to prevent premature atherosclerotic cardiovascular disease (CVD). However, underdiagnosis and undertreatment of FH persist. This study aimed to assess the knowledge and practice of FH care among general practitioners (GPs) in the Netherlands. METHODS: An internationally standardised, online questionnaire was sent to Dutch GPs between February 2021 and July 2022. The survey assessed knowledge and awareness of FH, encompassing general familiarity, awareness of management guidelines, inheritance, prevalence, CVD risk, and clinical practice related to FH. Comparative analysis was performed using data on primary care physicians from Western Australia, the Asia-Pacific region and the United Kingdom. RESULTS: Of the 221 participating GPs, 62.4% rated their familiarity with FH as above average (score > 4 on a 1-7 scale), with 91.4% considering themselves familiar with FH treatment and referral guidelines. Correct identification of the FH definition, typical lipid profile, inheritance pattern, prevalence and CVD risk was reported by 83.7%, 87.8%, 55.7%, 19.5%, and 13.6% of the respondents, respectively. Of the participants, 58.4% answered fewer than half of the 8 knowledge questions correctly. Dutch GPs reported greater FH familiarity and guideline awareness compared with their international counterparts but exhibited similar low performance on FH knowledge questions. CONCLUSION: Despite the Netherlands' relatively high FH detection rate, substantial knowledge gaps regarding FH persist among Dutch GPs, mirroring global trends. Enhanced FH education and awareness in primary care are imperative to improve FH detection and ensure adequate treatment. Targeting the global suboptimal understanding of FH might require international efforts.

Angiopoietin-like 3 inhibition and the liver: less is more?

PURPOSE OF REVIEW: The aim of this study was to discuss the potential mechanisms and implications of the opposing liver safety results from recent angiopoietin-like 3 (ANGPTL3) inhibition studies. RECENT FINDINGS: The clinical development of vupanorsen, a N-acetylgalactosamine (GalNAc) antisense targeting hepatic ANGPTL3, was recently discontinued due to a significant signal of liver transaminase increase. Vupanorsen elicited a dose-dependent increase in hepatic fat fraction up to 75%, whereas the small interfering RNA (siRNA) ARO-ANG3, has reported preliminary evidence of a dose-dependent decrease in hepatic fat fraction up to 30%. SUMMARY: ANGPTL3 inhibition is an attractive therapeutic target to reduce all apoB-containing lipoproteins. The discrepancy in liver signal results between the antisense and siRNA approach may be explained by the level of target inhibition. An alternative explanation may relate to off-target effects of vupanorsen, which have a molecule- and/or platform-specific origin. For intrahepatic strategies, highly potent ANGPTL3 inhibition will for now require special attention for liver safety.

Atorvastatin lowers 68Ga-DOTATATE uptake in coronary arteries, bone marrow and spleen in individuals with type 2 diabetes.

AIMS/HYPOTHESIS: Inflammation is a core component of residual cardiovascular risk in type 2 diabetes. With new anti-inflammatory therapeutics entering the field, accurate markers to evaluate their effectiveness in reducing cardiovascular disease are paramount. Gallium-68-labelled DOTATATE (68Ga-DOTATATE) has recently been proposed as a more specific marker of arterial wall inflammation than 18F-fluorodeoxyglucose (18F-FDG). This study set out to investigate whether 68Ga-DOTATATE uptake is amenable to therapeutic intervention in individuals with type 2 diabetes. METHODS: Individuals aged >50 years with type 2 diabetes underwent 68Ga-DOTATATE positron emission tomography (PET)/computed tomography (CT) at baseline and after 3 months treatment with atorvastatin 40 mg once daily. Primary outcome was the difference in coronary 68Ga-DOTATATE uptake, expressed as target-to-background ratio (TBR). The secondary outcome was difference in bone marrow and splenic uptake, expressed as the standardised uptake value (SUV). RESULTS: Twenty-two individuals with type 2 diabetes (mean age 63.2±6.4 years, 82% male, LDL-cholesterol 3.42±0.81 mmol/l, HbA1c 55±12 mmol/mol [7.2%±3.2%]) completed both 68Ga-DOTATATE PET/CT scans. The maximum TBR was -31% (95% CI -50, -12) lower in the coronary arteries, and bone marrow and splenic 68Ga-DOTATATE uptake was also significantly lower post statin treatment, with a mean percentage reduction of -15% (95% CI -27, -4) and -17% (95% CI -32, -2), respectively. CONCLUSIONS/INTERPRETATION: 68Ga-DOTATATE uptake across the cardio-haematopoietic axis was lower after statin therapy in individuals with type 2 diabetes. Therefore, 68Ga-DOTATATE is promising as a metric for vascular and haematopoietic inflammation in intervention studies using anti-inflammatory therapeutics in individuals with type 2 diabetes. TRIAL REGISTRATION: ClinicalTrials.gov NCT05730634.

Evinacumab in Patients with Refractory Hypercholesterolemia.

BACKGROUND: Patients with refractory hypercholesterolemia, who have high low-density lipoprotein (LDL) cholesterol levels despite treatment with lipid-lowering therapies at maximum tolerated doses, have an increased risk of atherosclerosis. In such patients, the efficacy and safety of subcutaneous and intravenous evinacumab, a fully human monoclonal antibody against angiopoietin-like 3, are not known. METHODS: In this double-blind, placebo-controlled, phase 2 trial, we enrolled patients with or without heterozygous familial hypercholesterolemia who had refractory hypercholesterolemia, with a screening LDL cholesterol level of 70 mg per deciliter or higher with atherosclerosis or of 100 mg per deciliter or higher without atherosclerosis. Patients were randomly assigned to receive subcutaneous or intravenous evinacumab or placebo. The primary end point was the percent change from baseline in the LDL cholesterol level at week 16 with evinacumab as compared with placebo. RESULTS: In total, 272 patients were randomly assigned to the following groups: subcutaneous evinacumab at a dose of 450 mg weekly (40 patients), 300 mg weekly (43 patients), or 300 mg every 2 weeks (39 patients) or placebo (41 patients); or intravenous evinacumab at a dose of 15 mg per kilogram of body weight every 4 weeks (39 patients) or 5 mg per kilogram every 4 weeks (36 patients) or placebo (34 patients). At week 16, the differences in the least-squares mean change from baseline in the LDL cholesterol level between the groups assigned to receive subcutaneous evinacumab at a dose of 450 mg weekly, 300 mg weekly, and 300 mg every 2 weeks and the placebo group were -56.0, -52.9, and -38.5 percentage points, respectively (P<0.001 for all comparisons). The differences between the groups assigned to receive intravenous evinacumab at a dose of 15 mg per kilogram and 5 mg per kilogram and the placebo group were -50.5 percentage points (P<0.001) and -24.2 percentage points, respectively. The incidence of serious adverse events during the treatment period ranged from 3 to 16% across trial groups. CONCLUSIONS: In patients with refractory hypercholesterolemia, the use of evinacumab significantly reduced the LDL cholesterol level, by more than 50% at the maximum dose. (Funded by Regeneron Pharmaceuticals; ClinicalTrials.gov number, NCT03175367.).

Antisense Inhibition of Prekallikrein to Control Hereditary Angioedema.

Hereditary angioedema is characterized by recurrent and unpredictable episodes of subcutaneous and mucosal swelling that can be life threatening. IONIS-PKK-LRx is a ligand-conjugated antisense oligonucleotide designed for receptor-mediated delivery to hepatocytes. In a compassionate-use pilot study, two patients with severe bradykinin-mediated angioedema were initially administered weekly subcutaneous injections of the unconjugated parent drug, IONIS-PKKRx, for 12 to 16 weeks, after which they received IONIS-PKK-LRx at a dose of 80 mg every 3 to 4 weeks for 7 to 8 months. Treatment was accompanied by a reduction in the angioedema attack rate. (Funded by Amsterdam UMC.).

Lipoprotein(a) Reduction in Persons with Cardiovascular Disease.

BACKGROUND: Lipoprotein(a) levels are genetically determined and, when elevated, are a risk factor for cardiovascular disease and aortic stenosis. There are no approved pharmacologic therapies to lower lipoprotein(a) levels. METHODS: We conducted a randomized, double-blind, placebo-controlled, dose-ranging trial involving 286 patients with established cardiovascular disease and screening lipoprotein(a) levels of at least 60 mg per deciliter (150 nmol per liter). Patients received the hepatocyte-directed antisense oligonucleotide AKCEA-APO(a)-LRx, referred to here as APO(a)-LRx (20, 40, or 60 mg every 4 weeks; 20 mg every 2 weeks; or 20 mg every week), or saline placebo subcutaneously for 6 to 12 months. The lipoprotein(a) level was measured with an isoform-independent assay. The primary end point was the percent change in lipoprotein(a) level from baseline to month 6 of exposure (week 25 in the groups that received monthly doses and week 27 in the groups that received more frequent doses). RESULTS: The median baseline lipoprotein(a) levels in the six groups ranged from 204.5 to 246.6 nmol per liter. Administration of APO(a)-LRx resulted in dose-dependent decreases in lipoprotein(a) levels, with mean percent decreases of 35% at a dose of 20 mg every 4 weeks, 56% at 40 mg every 4 weeks, 58% at 20 mg every 2 weeks, 72% at 60 mg every 4 weeks, and 80% at 20 mg every week, as compared with 6% with placebo (P values for the comparison with placebo ranged from 0.003 to <0.001). There were no significant differences between any APO(a)-LRx dose and placebo with respect to platelet counts, liver and renal measures, or influenza-like symptoms. The most common adverse events were injection-site reactions. CONCLUSIONS: APO(a)-LRx reduced lipoprotein(a) levels in a dose-dependent manner in patients who had elevated lipoprotein(a) levels and established cardiovascular disease. (Funded by Akcea Therapeutics; ClinicalTrials.gov number, NCT03070782.).

Daring to dream: Targeting lipoprotein(a) as a causal and risk-enhancing factor.

Lipoprotein(a) [Lp(a)], a distinct lipoprotein class, has become a major focus for cardiovascular research. This review is written in light of the recent guideline and consensus statements on Lp(a) and focuses on 1) the causal association between Lp(a) and cardiovascular outcomes, 2) the potential mechanisms by which elevated Lp(a) contributes to cardiovascular diseases, 3) the metabolic insights on the production and clearance of Lp(a) and 4) the current and future therapeutic approaches to lower Lp(a) concentrations. The concentrations of Lp(a) are under strict genetic control. There exists a continuous relationship between the Lp(a) concentrations and risk for various endpoints of atherosclerotic cardiovascular disease (ASCVD). One in five people in the Caucasian population is considered to have increased Lp(a) concentrations; the prevalence of elevated Lp(a) is even higher in black populations. This makes Lp(a) a cardiovascular risk factor of major public health relevance. Besides the association between Lp(a) and myocardial infarction, the relationship with aortic valve stenosis has become a major focus of research during the last decade. Genetic studies provided strong support for a causal association between Lp(a) and cardiovascular outcomes: carriers of genetic variants associated with lifelong increased Lp(a) concentration are significantly more frequent in patients with ASCVD. This has triggered the development of drugs that can specifically lower Lp(a) concentrations: mRNA-targeting therapies such as anti-sense oligonucleotide (ASO) therapies and short interfering RNA (siRNA) therapies have opened new avenues to lower Lp(a) concentrations more than 95%. Ongoing Phase II and III clinical trials of these compounds are discussed in this review.

Plasma Lipoprotein Lipase Is Associated with Risk of Future Major Adverse Cardiovascular Events in Patients Following Carotid Endarterectomy.

INTRODUCTION: Carotid plaque intraplaque haemorrhage (IPH) is associated with future cardiovascular events. It was hypothesised that plasma proteins associated with carotid plaque IPH are also likely to be associated with major adverse cardiovascular events (MACE) after carotid endarterectomy (CEA). METHODS: In pre-operative blood samples from patients undergoing CEA within the Athero-Express biobank, proteins involved in cardiovascular disease were measured using three OLINK proteomics immunoassays. The association between proteins and IPH was analysed using logistic regression analyses. Subsequently, the association between the IPH associated plasma proteins and the three year post-operative risk of MACE (including stroke, myocardial infarction, or cardiovascular death) was analysed. RESULTS: Within the three year follow up, 130 patients (18.9%) of 688 symptomatic and asymptomatic patients undergoing CEA developed MACE. Six of 276 plasma proteins were found to be significantly associated with IPH, from which only lipoprotein lipase (LPL) was associated with the post-operative risk of MACE undergoing CEA. Within the 30 day peri-operative period, high plasma LPL was independently associated with an increased risk of MACE (adjusted hazard ratio [HR] per standard deviation [SD] 1.60, 1.10 - 2.30), p = .014). From 30 days to three years, however, high LPL was associated with a lower risk of MACE (adjusted HR per SD 0.80, 0.65 - 0.99, p= .036). CONCLUSION: High LPL concentrations were found to be associated with a higher risk of MACE in the first 30 post-operative days but with a lower risk MACE between 30 days and three years, meaning that LPL has different hazards at different time points.

Targeted proteomics improves cardiovascular risk prediction in secondary prevention.

AIMS: Current risk scores do not accurately identify patients at highest risk of recurrent atherosclerotic cardiovascular disease (ASCVD) in need of more intensive therapeutic interventions. Advances in high-throughput plasma proteomics, analysed with machine learning techniques, may offer new opportunities to further improve risk stratification in these patients. METHODS AND RESULTS: Targeted plasma proteomics was performed in two secondary prevention cohorts: the Second Manifestations of ARTerial disease (SMART) cohort (n = 870) and the Athero-Express cohort (n = 700). The primary outcome was recurrent ASCVD (acute myocardial infarction, ischaemic stroke, and cardiovascular death). Machine learning techniques with extreme gradient boosting were used to construct a protein model in the derivation cohort (SMART), which was validated in the Athero-Express cohort and compared with a clinical risk model. Pathway analysis was performed to identify specific pathways in high and low C-reactive protein (CRP) patient subsets. The protein model outperformed the clinical model in both the derivation cohort [area under the curve (AUC): 0.810 vs. 0.750; P < 0.001] and validation cohort (AUC: 0.801 vs. 0.765; P < 0.001), provided significant net reclassification improvement (0.173 in validation cohort) and was well calibrated. In contrast to a clear interleukin-6 signal in high CRP patients, neutrophil-signalling-related proteins were associated with recurrent ASCVD in low CRP patients. CONCLUSION: A proteome-based risk model is superior to a clinical risk model in predicting recurrent ASCVD events. Neutrophil-related pathways were found in low CRP patients, implying the presence of a residual inflammatory risk beyond traditional NLRP3 pathways. The observed net reclassification improvement illustrates the potential of proteomics when incorporated in a tailored therapeutic approach in secondary prevention patients.

Lipoprotein(a) is associated with the onset but not the progression of aortic valve calcification.

AIM: Lipoprotein(a) [Lp(a)] is a potential causal factor in the pathogenesis of aortic valve disease. However, the relationship of Lp(a) with new onset and progression of aortic valve calcium (AVC) has not been studied. The purpose of the study was to assess whether high serum levels of Lp(a) are associated with AVC incidence and progression. METHODS AND RESULTS: A total of 922 individuals from the population-based Rotterdam Study (mean age 66.0±4.2 years, 47.7% men), whose Lp(a) measurements were available, underwent non-enhanced cardiac computed tomography imaging at baseline and after a median follow-up of 14.0 [interquartile range (IQR) 13.9-14.2] years. New-onset AVC was defined as an AVC score >0 on the follow-up scan in the absence of AVC on the first scan. Progression was defined as the absolute difference in AVC score between the baseline and follow-up scan. Logistic and linear regression analyses were performed to evaluate the relationship of Lp(a) with baseline, new onset, and progression of AVC. All analyses were corrected for age, sex, body mass index, smoking, hypertension, dyslipidaemia, and creatinine. AVC progression was analysed conditional on baseline AVC score expressed as restricted cubic splines. Of the 702 individuals without AVC at baseline, 415 (59.1%) developed new-onset AVC on the follow-up scan. In those with baseline AVC, median annual progression was 13.5 (IQR = 5.2-37.8) Agatston units (AU). Lipoprotein(a) concentration was independently associated with baseline AVC [odds ratio (OR) 1.43 for each 50 mg/dL higher Lp(a); 95% confidence interval (CI) 1.15-1.79] and new-onset AVC (OR 1.30 for each 50 mg/dL higher Lp(a); 95% CI 1.02-1.65), but not with AVC progression (ß: -71 AU for each 50 mg/dL higher Lp(a); 95% CI -117; 35). Only baseline AVC score was significantly associated with AVC progression (P < 0.001). CONCLUSION: In the population-based Rotterdam Study, Lp(a) is robustly associated with baseline and new-onset AVC but not with AVC progression, suggesting that Lp(a)-lowering interventions may be most effective in pre-calcific stages of aortic valve disease.