A machine-learning algorithm using claims data to identify patients with homozygous familial hypercholesterolemia.

Homozygous familial hypercholesterolemia (HoFH) is an underdiagnosed and undertreated ultra-rare disease. We utilized claims data from the Komodo Healthcare Map database to develop a machine-learning model to identify potential HoFH patients. We tokenized patients enrolled in MyRARE (patient support program for those prescribed evinacumab-dgnb in the United States) and linked them with their Komodo claims. A true positive HoFH cohort (n = 331) was formed by including patients from MyRARE and patients with prescriptions for evinacumab-dgnb or lomitapide. The negative cohort (n = 1423) comprised patients with or at risk for cardiovascular disease. We divided the cohort into an 80% training and 20% testing set. Overall, 10,616 candidate features were investigated; 87 were selected due to clinical relevance and importance on prediction performance. Different machine-learning algorithms were explored, with fast interpretable greedy-tree sums selected as the final machine-learning tool. This selection was based on its satisfactory performance and its easily interpretable nature. The model identified four useful features and yielded precision (positive predicted value) of 0.98, recall (sensitivity) of 0.88, area under the receiver operating characteristic curve of 0.98, and accuracy of 0.97. The model performed well in identifying HoFH patients in the testing set, providing a useful tool to facilitate HoFH screening and diagnosis via healthcare claims data.

Real-world safety and efficacy of lomitapide in homozygous familial hypercholesterolemia: interim report of special-use survey in Japan.

Aim: To evaluate the safety and efficacy of lomitapide in real-world clinical practice in Japan. Patients & methods: Interim analysis of 39 patients with homozygous familial hypercholesterolemia from an all-case surveillance study. Results: Median lomitapide dose (across 42 months) was 9.8 mg/day. 74 drug-related adverse events (AEs) were reported in 24 (61.5%) patients, including 14 (35.9%) with liver-related AEs, 19 (48.7%) with gastrointestinal disorders and 1 (2.6%) bleeding disorder. Lomitapide dose was reduced for 39.2% of drug-related AEs, withdrawn temporarily for 12.2%, and discontinued for 1 event (1.4%). Mean ± SD blood LDL-C level decreased from 225.9 ± 172.0 mg/dl (5.8 ± 4.5 mmol/l) predose to 159.4 ± 93.0 mg/dl (4.1 ± 2.4 mmol/l) at 12 months (p = 0.0245). Conclusion: This interim analysis suggests lomitapide is safe and effective in real-world clinical practice in Japan.

What is this article about? Lomitapide is a drug used to treat homozygous familial hypercholesterolemia (HoFH), a rare inherited disorder that causes very high cholesterol levels. Because HoFH is rare, only a limited number of patients were enrolled into the clinical trials that showed it was safe and effective, before its approval. Therefore, a study is now underway to evaluate the efficacy and safety of lomitapide when it is used in daily clinical practice in Japan. We have analyzed data for 39 patients who have been enrolled in this study so far. What are the results? We found that although most patients experienced some side effects, only one patient had to discontinue lomitapide. Most side effects could be managed without having to alter lomitapide treatment, or in some cases by reducing the dose or stopping the drug temporarily. We also found that lomitapide reduced cholesterol levels. What do the results mean? The results suggest that lomitapide is generally safe and effective in patients with HoFH being treated in routine clinical practice. The study is ongoing and additional analyses will be performed when a greater number of patients have been treated.

Sex Differences in Diagnosis, Treatment, and Cardiovascular Outcomes in Homozygous Familial Hypercholesterolemia.

Importance: Homozygous familial hypercholesterolemia (HoFH) is a rare genetic condition characterized by extremely increased low-density lipoprotein (LDL) cholesterol levels and premature atherosclerotic cardiovascular disease (ASCVD). Heterozygous familial hypercholesterolemia (HeFH) is more common than HoFH, and women with HeFH are diagnosed later and undertreated compared to men; it is unknown whether these sex differences also apply to HoFH. Objective: To investigate sex differences in age at diagnosis, risk factors, lipid-lowering treatment, and ASCVD morbidity and mortality in patients with HoFH. Design, Setting, and Participants: Sex-specific analyses for this retrospective cohort study were performed using data from the HoFH International Clinical Collaborators (HICC) registry, the largest global dataset of patients with HoFH, spanning 88 institutions across 38 countries. Patients with HoFH who were alive during or after 2010 were eligible for inclusion. Data entry occurred between February 2016 and December 2020. Data were analyzed from June 2022 to June 2023. Main Outcomes and Measures: Comparison between women and men with HoFH regarding age at diagnosis, presence of risk factors, lipid-lowering treatment, prevalence, and onset and incidence of ASCVD morbidity (myocardial infarction [MI], aortic stenosis, and combined ASCVD outcomes) and mortality. Results: Data from 389 women and 362 men with HoFH from 38 countries were included. Women and men had similar age at diagnosis (median [IQR], 13 [6-26] years vs 11 [5-27] years, respectively), untreated LDL cholesterol levels (mean [SD], 579 [203] vs 596 [186] mg/dL, respectively), and cardiovascular risk factor prevalence, except smoking (38 of 266 women [14.3%] vs 59 of 217 men [27.2%], respectively). Prevalence of MI was lower in women (31 of 389 [8.0%]) than men (59 of 362 [16.3%]), but age at first MI was similar (mean [SD], 39 [13] years in women vs 38 [13] years in men). Treated LDL cholesterol levels and lipid-lowering therapy were similar in both sexes, in particular statins (248 of 276 women [89.9%] vs 235 of 258 men [91.1%]) and lipoprotein apheresis (115 of 317 women [36.3%] vs 118 of 304 men [38.8%]). Sixteen years after HoFH diagnosis, women had statistically significant lower cumulative incidence of MI (5.0% in women vs 13.7% in men; subdistribution hazard ratio [SHR], 0.37; 95% CI, 0.21-0.66) and nonsignificantly lower all-cause mortality (3.0% in women vs 4.1% in men; HR, 0.76; 95% CI, 0.40-1.45) and cardiovascular mortality (2.6% in women vs 4.1% in men; SHR, 0.87; 95% CI, 0.44-1.75). Conclusions and Relevance: In this cohort study of individuals with known HoFH, MI was higher in men compared with women yet age at diagnosis and at first ASCVD event were similar. These findings suggest that early diagnosis and treatment are important in attenuating the excessive cardiovascular risk in both sexes.

Unveiling Familial Hypercholesterolemia-Review, Cardiovascular Complications, Lipid-Lowering Treatment and Its Efficacy.

Familial hypercholesterolemia (FH) is a genetic disorder primarily transmitted in an autosomal-dominant manner. We distinguish two main forms of FH, which differ in the severity of the disease, namely homozygous familial hypercholesterolemia (HoFH) and heterozygous familial hypercholesterolemia (HeFH). The characteristic feature of this disease is a high concentration of low-density lipoprotein cholesterol (LDL-C) in the blood. However, the level may significantly vary between the two mentioned types of FH, and it is decidedly higher in HoFH. A chronically elevated concentration of LDL-C in the plasma leads to the occurrence of certain abnormalities, such as xanthomas in the tendons and skin, as well as corneal arcus. Nevertheless, a significantly more severe phenomenon is leading to the premature onset of cardiovascular disease (CVD) and its clinical implications, such as cardiac events, stroke or vascular dementia, even at a relatively young age. Due to the danger posed by this medical condition, we have investigated how both non-pharmacological and selected pharmacological treatment impact the course of FH, thereby reducing or postponing the risk of clinical manifestations of CVD. The primary objective of this review is to provide a comprehensive summary of the current understanding of FH, the effectiveness of lipid-lowering therapy in FH and to explain the anatomopathological correlation between FH and premature CVD development, with its complications.

The Effect of PCSK9 Inhibitors on LDL-C Target Achievement in Patients with Homozygous Familial Hypercholesterolemia: A Retrospective Cohort Analysis.

INTRODUCTION: Achieving target low-density lipoprotein-cholesterol (LDL-C) levels remains challenging when treating homozygous familial hypercholesterolemia (HoFH). Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) are prescribed in addition to statins and ezetimibe, but patients' response varies and depends on residual low-density lipoprotein receptor (LDLR) function. METHODS: A multicenter, retrospective observational analysis evaluated LDL-C target achievement in response to PCSK9i treatment in 28 patients with HoFH from the Middle East/North Africa region. Effect of genotype was investigated. Demographic and clinical information was retrospectively obtained from medical records. Patient response to PCSK9i treatment was assessed by calculating percentage changes in lipid levels from pre-PCSK9i treatment baseline to most recent follow-up visit where patients were recorded as receiving PCSK9i on top of standard of care lipid-lowering therapies (LLTs; i.e., statins/ezetimibe) and assessing European Atherosclerosis Society (EAS) target achievement up to January 31, 2022. Lowest LDL-C level while receiving PCSK9i was identified. RESULTS: The cohort (n = 28) had a mean age (standard deviation; SD) of 22.8 (9.8) years (n = 28) and was 51% female (n = 27). Baseline LDL-C data were available in 24/28 (85.7%) patients (mean [SD] 14.0 [3.0] mmol/L). Median (interquartile range) duration of PCSK9i treatment was 12.0 months (4.0-19.1) months and mean (SD) % change in LDL-C after PCSK9i treatment was - 8.6% (12.1). LDL-C reduction from baseline was below 15% in 17/24 patients (70.8%). In the full cohort, mean (SD) minimum LDL-C during PCSK9i treatment was 11.9 (2.8; n = 28) mmol/L. No patient achieved EAS target LDL-C while receiving PCSK9i; genotype analysis suggested LDLR-null/null patients were most refractory to PCSK9i. CONCLUSION: Response to PCSK9i was minimal in this cohort of patients with HoFH. No patients achieved EAS LDL-C targets, and most failed to reach the EAS-recommended 15% LDL-C reduction for PCSK9i therapy continuation. These results suggest additional LLTs are necessary to achieve LDL-C targets in HoFH.

Evinacumab-dgnb (Evkeeza-REGN1500), A Novel Lipid-Lowering Therapy for Homozygous Familial Hypercholesterolemia.

Chronically elevated low-density lipoprotein (LDL) has harmful effects on the vasculature including increased vasoconstriction and the formation of plaques which may rupture, causing coronary heart disease and stroke. In patients with familial hypercholesterolemia, adequate reduction of LDL is especially challenging. Although HMG-CoA reductase inhibitors (statins) are the mainstays for LDL lowering, other treatments such as proprotein convertase subtilisin/kexin type 9 inhibitors, bempedoic acid, incliseran, lomitapide, and apheresis have been employed in an effort to achieve adequate LDL reduction in these patients. Despite these available therapies, many patients with familial hypercholesterolemia do not meet the LDL targets suggested in current guidelines. Evinacumab is a novel lipid-lowering therapy that exerts its LDL-lowering effect through inhibition of angiopoietin-like protein 3 (ANGPTL3). ANGPTL3 inhibits the breakdown of triglyceride-rich lipoproteins, such as very low-density lipoprotein and chylomicrons. By inhibiting ANGPTL3, evinacumab allows these lipoproteins to be degraded, ultimately leading to reductions in LDL, high-density lipoprotein, and triglycerides. Clinical trials have demonstrated evinacumab to be safe and effective in reducing LDL. However, data are lacking regarding its potential to reduce risk of atherosclerotic cardiovascular disease. Evinacumab is generally well tolerated with the primary adverse effects comprising infusion reactions, nasopharyngitis, influenza-like illness, dizziness, rhinorrhea, and nausea. While evinacumab is an interesting therapy, until it is proven to reduce cardiovascular events, its high cost leaves its anticipated role in therapy somewhat ambiguous. In the meantime, it may be a useful therapy for those with homozygous familial hypercholesterolemia.

Efficacy, Safety, and Tolerability of Inclisiran in Patients With Homozygous Familial Hypercholesterolemia: Results From the ORION-5 Randomized Clinical Trial.

BACKGROUND: Homozygous familial hypercholesterolemia is a genetic disease characterized by extremely high levels of low-density lipoprotein cholesterol (LDL-C) and a high risk of premature cardiovascular events. The proof-of-concept study ORION-2 (A Study of Inclisiran in Participants With Homozygous Familial Hypercholesterolemia) showed that inclisiran, a small interfering RNA that prevents production of the hepatic PCSK9 protein (proprotein convertase subtilisin/kexin type 9), could lead to durable reductions in LDL-C levels when added to statins and ezetimibe in patients with homozygous familial hypercholesterolemia. METHODS: ORION-5 was a phase 3, 2-part, multicenter study in 56 patients with homozygous familial hypercholesterolemia and elevated LDL-C levels despite maximum tolerated doses of LDL-C-lowering therapies with or without lipoprotein apheresis. Patients eligible for part 1 (double-blind, 6 months) were randomized 2:1 to receive either 300 mg of inclisiran sodium (equivalent to 284 mg of inclisiran) or placebo. Placebo-treated patients from part 1 were transitioned to inclisiran in part 2 (open-label, 18 months). The primary end point was the percentage change in LDL-C levels from baseline to day 150. RESULTS: The mean age of the patients was 42.7 years, and 60.7% were women. The mean baseline LDL-C levels were 294.0 mg/dL and 356.7 mg/dL in the inclisiran and placebo groups, respectively. The placebo-corrected percentage change in LDL-C level from baseline to day 150 was -1.68% (95% CI, -29.19% to 25.83%; P=0.90), and the difference was not statistically significant between the inclisiran and placebo groups. The placebo-corrected percentage change in PCSK9 levels from baseline to day 150 was -60.6% with inclisiran treatment (P<0.0001); this was sustained throughout the study, confirming the effect of inclisiran on its biological target of PCSK9. No statistically significant differences between the inclisiran and placebo groups were observed in the levels of other lipids and lipoproteins (apolipoprotein B, total cholesterol, and non-high-density lipoprotein cholesterol). Adverse events and serious adverse events did not differ between the inclisiran and placebo groups throughout the study. CONCLUSIONS: Inclisiran treatment did not reduce LDL-C levels in patients with homozygous familial hypercholesterolemia despite substantial lowering of PCSK9 levels. Inclisiran was well-tolerated, and the safety findings were consistent with previously reported studies and the overall safety profile. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03851705.

Evinacumab for Pediatric Patients With Homozygous Familial Hypercholesterolemia.

BACKGROUND: Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disorder characterized by severely elevated low-density lipoprotein cholesterol (LDL-C) levels due to profoundly defective LDL receptor (LDLR) function. Given that severely elevated LDL-C starts in utero, atherosclerosis often presents during childhood or adolescence, creating a largely unmet need for aggressive LDLR-independent lipid-lowering therapies in young patients with HoFH. Here we present the first evaluation of the efficacy and safety of evinacumab, a novel LDLR-independent lipid-lowering therapy, in pediatric patients with HoFH from parts A and B of a 3-part study. METHODS: The phase 3, part B, open-label study treated 14 patients 5 to 11 years of age with genetically proven HoFH (true homozygotes and compound heterozygotes) with LDL-C >130 mg/dL, despite optimized lipid-lowering therapy (including LDLR-independent apheresis and lomitapide), with intravenous evinacumab 15 mg/kg every 4 weeks. RESULTS: Evinacumab treatment rapidly and durably (through week 24) decreased LDL-C with profound reduction in the first week, with a mean (SE) LDL-C reduction of -48.3% (10.4%) from baseline to week 24. ApoB (mean [SE], -41.3% [9.0%]), non-high-density lipoprotein cholesterol (-48.9% [9.8%]), and total cholesterol (-49.1% [8.1%]) were similarly decreased. Treatment-emergent adverse events were reported in 10 (71.4%) patients; however, only 2 (14.3%) reported events that were considered to be treatment-related (nausea and abdominal pain). One serious treatment-emergent adverse event of tonsillitis occurred (n=1), but this was not considered treatment-related. CONCLUSIONS: Evinacumab constitutes a new treatment for pediatric patients with HoFH and inadequately controlled LDL-C despite optimized lipid-lowering therapy, lowering LDL-C levels by nearly half in these extremely high-risk and difficult-to-treat individuals. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04233918.

Evinacumab-dgnb (Evkeeza®) en niños con hipercolesterolemia familiar homocigota / Evinacumab-dgnb (Evkeeza®) in children with homozygous familial hypercholesterolemia

INTRODUCCIÓN: La hipercolesterolemia familiar (FH) es un trastorno hereditario que exhibe herencia autosómica dominante y que se expresa como una eliminación retardada de LDL plasmático, causada por mutaciones de los genes implicados en la vía mediada por el receptor de LDL. Se estima que la FH heterocigótica (HeFH) ocurre en aproximadamente 1 de cada 200 a 300 personas. Por el contrario, la FH homocigótica (HoFH) es una enfermedad que se encuentra en el listado de enfermedades poco frecuentes del Ministerio de Salud de la Nación (ORPHACODE 391665), con una prevalencia mundial estimada de aproximadamente 1:300.000 a 1:400.000. El diagnóstico de la HoFH debe ser mediante pruebas genéticas en personas con sospecha clínica: LDL-C no tratado >500 mg/dL (>13 mmol/L) o LDL-C tratado ≥300 mg/dL (>8 mmol/L), junto con xantoma cutáneo o tendinoso antes de los 10 años de edad, y/o niveles elevados de LDL-C compatibles con HeFH en ambos padres. Es importante señalar que se pueden observar niveles de LDL-C no tratados. Los personas con FH heterocigoto (HeFH) portan el gen mutado en un solo alelo y tienen niveles plasmáticos de LDL-C el doble de lo normal o más, y pueden experimentar el primer evento cardiovascular tan pronto como a los treinta años. Con mutaciones en ambos alelos, la HoFH exhibe niveles de LDL-C que duplican los de la HeFH, o incluso más, y los personas desarrollan complicaciones cardiovasculares incluso en la primera década de sus vidas.1,2 Los niños con HoFH deben someterse a una evaluación cardiovascular integral continuo con electrocardiogramas, ecocardiografías, pruebas funcionales de esfuerzo e imágenes de la arteria coronaria. El manejo de la enfermedad comprende la adopción de hábitos saludables para el corazón junto con tratamiento farmacológico. En este documento se plantea evaluar la eficacia y seguridad del uso de evinacumab (Evkeeza®) en niños con HoFH. TECNOLOGÍA: Evinacumab-dgnb es un anticuerpo monoclonal de isotopo IgG4 humano recombinante que se une e inhibe la proteína similar a la angiopoyetina 3 (ANGPTL3), una proteína reguladora que desempeña un papel en el metabolismo de los lípidos mediante la inhibición de la lipoproteína lipasa (LPL) y la lipasa endotelial (EL). 6 La inhibición de ANGPTL3 conduce a reducciones en LDLC, HDL-C y triglicéridos (TG). Evinacumab-dgnb reduce el LDL-C, independientemente de la presencia del receptor de LDL (con actividad del receptor de LDL prácticamente ausente o alterada), al promover el procesamiento y la eliminación de las lipoproteínas de muy baja densidad y la formación de LDL. OBJETIVO: El objetivo del presente informe es evaluar rápidamente los parámetros de eficacia, seguridad, costos y recomendaciones disponibles acerca del empleo del uso de evinacumab (Evkeeza®) en niños con HoFH. MÉTODOS: Se realizó una búsqueda bibliográfica en las principales bases de datos tales como PUBMED, LILACS, BRISA, COCHRANE, SCIELO, EMBASE, TRIPDATABASE como así también en sociedades científicas, agencias reguladoras, financiadores de salud y agencias de evaluación de tecnologías sanitarias. Se priorizó la inclusión de revisiones sistemáticas, ensayos clínicos controlados aleatorizados, evaluación de tecnología sanitaria y guías de práctica clínica de alta calidad metodológica. RECOMENDACIONES: No se hallaron guías de práctica clínica actualizadas en Argentina y en el Mundo que recomienden la tecnología en la indicación evaluada, antes o después de la autorización de comercialización por parte de la FDA.5,13,14 La Sociedad Europea de Aterosclerosis publicó en 2023 una actualización sobre su consenso en personas con HoFH.5 El panel hace una mención para niños/adolecentes y adultos por igual, donde menciona a la aféresis, el evinacumab o la lomitapida (no disponible en Argentina) como alternativas en personas con HoFH que no responden a la combinación de estatinas a dosis máximas tolerables, ezetimibe e inhibidores de PCSK9. También menciona que en muchos países de Europa el precio del fármaco será una limitante para su uso y serán alternativas viables comenzar con la aféresis. El Instituto Nacional para la Excelencia en Salud y Atención (NICE, sus siglas del inglés National Institute for Health and Care Excellence) de Reino Undo y la Agencia Canadiense de Medicamentos y Tecnologías en Salud (CADTH, su sigla del inglés Canadian Agency for Drugs and Technologies in Health) recientemente han comenzado a evaluar la tecnología en la indicación evaluada. CONCLUSIONES: La evidencia que sustenta la aprobación de comercialización por parte de los Estados Unidos de evinacumab-dgnb (Evkeeza®) en niños con hipercolesterolemia familiar homocigota se basa en un único ensayo clínico abierto y sin comparador de fase III. Cabe señalar que actualmente la Europa lo autorizó solo en mayores de 12 años. No se hallaron estudios que hayan evaluado el evinacumab-dgnb sobre desenlaces clínicos relevantes para la enfermedad o la reducción de la aféresis, como tampoco que lo compare frente a otros tratamientos farmacológicos disponibles para la población objetivo. El estudio identificado demostró que en 14 niños con hipercolesterolemia familiar homocigota resistentes al tratamiento farmacológico, la administración de evinacumab-dgnb podría mejorar al muy corto plazo parámetros de laboratorios importantes para el seguimiento de la enfermedad. No se hallaron guías de práctica clínica actualizadas en Argentina y en el Mundo que recomienden la tecnología en la indicación evaluada, antes o después de la autorización de comercialización por parte de los Estados Unidos. Una guía europea la menciona en niños pero por fuera de la actual autorización de comercialización del continente. Según los precios de adquisición relevados en ese país, para un niño de 25 kg, el costo mensual del fármaco sería de aproximadamente USD 12.288,53 (ARS 4.491.458 noviembre/23).

Real-World Effectiveness of PCSK9 Inhibitors in Reducing LDL-C in Patients With Familial Hypercholesterolemia in Italy: A Retrospective Cohort Study Based on the AIFA Monitoring Registries.

Background Information on the real-world use of proprotein convertase subtilisin kexin 9 inhibitors (PCKS9is) in familial hypercholesterolemia are limited. We evaluated the pattern of prescription and the long-term efficacy of alirocumab and evolocumab in Italian patients with familial hypercholesterolemia in clinical practice. Methods and Results The data set for analysis was extracted from the PCKS9i Italian Medicines Agency (AIFA) registry and included 2484 patients with heterozygous familial hypercholesterolemia (HeFH) and 62 patients with homozygous familial hypercholesterolemia (HoFH) who were prescribed PCKS9is from February 2017 to December 2021. As the follow-up schedules were not prespecified and could vary, persistence and adherence as well as low-density lipoprotein cholesterol (LDL-C) changes during 2 years of treatment were analyzed in a final cohort of 1299 patients with familial hypercholesterolemia. At baseline, 53.8% of patients with HeFH and 69.4% of patients with HoFH were receiving maximally tolerated lipid-lowering therapies, while 45.9% of patients with HeFH and 30.7% of patients with HoFH reported statin intolerance; mean LDL-C was 197.7±52.3 mg/dL in HeFH and 252.0±106.2 mg/dL in HoFH. The 6-month persistence and adherence to therapy were >85%, and LDL-C reduction reached 58.6% (to 79.7 mg/dL) in HeFH and 57.6% (to 95.1 mg/dL) in HoFH after 24 months of treatment. The European Atherosclerosis Society/European Society of Cardiology LDL-C goals were achieved in 43.3% of patients with HeFH and 37.5% of patients with HoFH. Conclusions PCKS9i prescribed to patients with familial hypercholesterolemia in clinical practice showed LDL-C-lowering efficacy similar to that observed in controlled trials. However, 2 of 5 HeFH cases and 2 of 6 HoFH cases achieved the recommended LDL-C goals. The full achievement of European Atherosclerosis Society/European Society of Cardiology LDL-C goals should require a lower threshold for PCKS9i initiation and a combination of multiple therapies.

New opportunities in the management and treatment of refractory hypercholesterolemia using in vivo CRISPR-mediated genome/base editing.

AIMS: Refractory hypercholesterolemia (RH), caused primarily by the loss-of-function mutation of LDL receptor (LDLR) gene seen in HoFH and HeFH patients, remains a major risk factor for atherosclerotic cardiovascular disease (ASCVD). Statin and ezetimibe combination therapy lower circulating LDL by 30% in HoFH patients. PCSK9 mAB, being an LDLR-dependent therapy, is not effective in HoFH, but lowers LDL by 25% in HeFH patients. A maximum reduction of 50% was noted in HoFH patients treated with ANGPTL3 mAB, which was not enough to achieve therapeutic goal of LDL. Therefore, new approaches are warranted to offer hopes to individuals intolerant to higher dose statins and not able to achieve recommended LDL level. DATA SYNTHESIS: New approaches to lower LDL include gene therapy and gene editing. AAV-based gene therapy has shown encouraging results in animal models. Using CRISPR/Cas9-mediated genome/base editing, gain of function and loss of function have been successfully done in animal models. Recent progress in the refinement of genome/base editing has overcome the issues of off-target mutagenesis with ∼1% mutagenesis in case of PCSK9 and almost no off-target mutagenesis in inactivating ANGPTL3 in animal models showing 50% reduction in cholesterol. Current approaches using CRISPR-Cas9 genome/base editing targeting LDLR-dependent and LDLR-independent pathways are underway. CONCLUSIONS: The new information on gain of LDLR function and inactivation of ANGPTL3 together with developments in genome/base editing technology to overcome off-target insertion and deletion mutagenesis offer hope to refractory hypercholesterolemic individuals who are at a higher risk of developing ASCVD.

Long-term outcomes of liver transplantation for homozygous familial hypercholesterolaemia in Australia and New Zealand.

BACKGROUND AND AIMS: Homozygous familial hypercholesterolaemia (FH) causes severe cardiovascular disease from childhood. Conventional drug therapy is usually ineffective; lipoprotein apheresis (LA) is often required. Liver transplantation (LT) can correct the metabolic defect but is considered a treatment of last resort. Newer drugs including lomitapide and evinacumab might reduce the need for apheresis and LT. We sought to determine the long-term outcomes following LT in Australia and New Zealand. METHODS: We analysed demographic, biochemical and clinical data from all patients in Australia and New Zealand who have received LT for homozygous FH, identified from the Australia and New Zealand Liver and Intestinal Transplant Registry. RESULTS: Nine patients (five female; one deceased; seven aged between 3 and 6 years at the time of LT and two aged 22 and 26 years) were identified. Mean follow-up was 14.1 years (range 4-27). Baseline LDL-cholesterol off all treatment was 23 ± 4.1 mmol/L. Mean LDL-cholesterol on medical therapy (including maximal statin therapy in all patients, ezetimibe in three and LA in five) was 11 ± 5.7 mmol/L (p < 0.001). After LT, mean LDL-cholesterol was 2.6 ± 0.9 mmol/L (p = 0.004) with three patients remaining on statin therapy and none on LA. One patient died from acute myocardial infarction (AMI) three years after LT. Two patients required aortic valve replacement, more than 10 years after LT. The remaining six patients were asymptomatic after eight to 21 years of follow-up. No significant adverse events associated with immunosuppression were reported. CONCLUSIONS: LT for homozygous FH was highly effective in achieving substantial long-term reduction in LDL-cholesterol concentrations in all nine patients. LT remains an option for severe cases of homozygous FH where drug therapy combined with apheresis is ineffective or unfeasible.

Metabolic systems approaches update molecular insights of clinical phenotypes and cardiovascular risk in patients with homozygous familial hypercholesterolemia.

BACKGROUND: Homozygous familial hypercholesterolemia (HoFH) is an orphan metabolic disease characterized by extremely elevated low-density lipoprotein cholesterol (LDL-C), xanthomas, aortic stenosis, and premature atherosclerotic cardiovascular disease (ASCVD). In addition to LDL-C, studies in experimental models and small clinical populations have suggested that other types of metabolic molecules might also be risk factors responsible for cardiovascular complications in HoFH, but definitive evidence from large-scale human studies is still lacking. Herein, we aimed to comprehensively characterize the metabolic features and risk factors of human HoFH by using metabolic systems strategies. METHODS: Two independent multi-center cohorts with a total of 868 individuals were included in the cross-sectional study. First, comprehensive serum metabolome/lipidome-wide analyses were employed to identify the metabolomic patterns for differentiating HoFH patients (n = 184) from heterozygous FH (HeFH, n = 376) and non-FH (n = 100) subjects in the discovery cohort. Then, the metabolomic patterns were verified in the validation cohort with 48 HoFH patients, 110 HeFH patients, and 50 non-FH individuals. Subsequently, correlation/regression analyses were performed to investigate the associations of clinical/metabolic alterations with typical phenotypes of HoFH. In the prospective study, a total of 84 HoFH patients with available follow-up were enrolled from the discovery cohort. Targeted metabolomics, deep proteomics, and random forest approaches were performed to investigate the ASCVD-associated biomarkers in HoFH patients. RESULTS: Beyond LDL-C, various bioactive metabolites in multiple pathways were discovered and validated for differentiating HoFH from HoFH and non-FH. Our results demonstrated that the inflammation and oxidative stress-related metabolites in the pathways of arachidonic acid and lipoprotein(a) metabolism were independently associated with the prevalence of corneal arcus, xanthomas, and supravalvular/valvular aortic stenosis in HoFH patients. Our results also identified a small marker panel consisting of high-density lipoprotein cholesterol, lipoprotein(a), apolipoprotein A1, and eight proinflammatory and proatherogenic metabolites in the pathways of arachidonic acid, phospholipid, carnitine, and sphingolipid metabolism that exhibited significant performances on predicting first ASCVD events in HoFH patients. CONCLUSIONS: Our findings demonstrate that human HoFH is associated with a variety of metabolic abnormalities and is more complex than previously known. Furthermore, this study provides additional metabolic alterations that hold promise as residual risk factors in HoFH population.

Modelling the potential long-term survival benefit of evinacumab treatment vs. standard of care in patients with homozygous familial hypercholesterolaemia.

AIMS: Despite intensive lipid-lowering therapies (LLTs), most patients with homozygous familial hypercholesterolaemia (HoFH) do not achieve guideline recommended low-density lipoprotein cholesterol (LDL-C) targets and are at increased risk of premature cardiovascular death. This analysis aimed to predict the impact of evinacumab and standard-of-care LLTs on life expectancy in an HoFH population using mathematical modelling. METHODS AND RESULTS: Mathematical models were developed using efficacy data for evinacumab from the phase 3 ELIPSE HoFH trial plus efficacy data for standard-of-care LLTs from peer-reviewed publications. Treatment strategies evaluated included (i) untreated, (ii) high-intensity statin (HIS) only, (iii) HIS plus ezetimibe, (iv) HIS plus ezetimibe plus proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i), and (v) HIS plus ezetimibe plus PCSK9i plus evinacumab. Markov analyses were used to assess differences in survival probability for different LLT strategies. The median survival for untreated HoFH patients was only 33-43 years, depending on different assumptions on baseline untreated LDL-C levels. In the most robust model, we estimated that HIS increased median survival by 9 years and ezetimibe further increased median survival by an additional 9 years. When PCSK9i was added on top of HIS plus ezetimibe, median survival was further improved by 14 years. Finally, the addition of evinacumab to standard-of-care LLTs was estimated to increase median survival by ∼12 years. CONCLUSION: In this mathematical modelling analysis, evinacumab treatment could potentially increase long-term survival vs. standard-of-care LLTs for patients with HoFH.

This mathematical modelling analysis demonstrated that evinacumab in addition to standard-of-care lipid-lowering treatments (LLTs; high-intensity statin plus ezetimibe plus proprotein convertase subtilisin/kexin type 9 inhibitor) could increase long-term survival to a median of 77 years vs. the 65 years achieved with only standard-of-care LLTs in patients with homozygous familial hypercholesterolaemia.

A Review of Progress on Targeting LDL Receptor-Dependent and -Independent Pathways for the Treatment of Hypercholesterolemia, a Major Risk Factor of ASCVD.

Since the discovery of the LDL receptor in 1973 by Brown and Goldstein as a causative protein in hypercholesterolemia, tremendous amounts of effort have gone into finding ways to manage high LDL cholesterol in familial hypercholesterolemic (HoFH and HeFH) individuals with loss-of-function mutations in the LDL receptor (LDLR) gene. Statins proved to be the first blockbuster drug, helping both HoFH and HeFH individuals by inhibiting the cholesterol synthesis pathway rate-limiting enzyme HMG-CoA reductase and inducing the LDL receptor. However, statins could not achieve the therapeutic goal of LDL. Other therapies targeting LDLR include PCSK9, which lowers LDLR by promoting LDLR degradation. Inducible degrader of LDLR (IDOL) also controls the LDLR protein, but an IDOL-based therapy is yet to be developed. Among the LDLR-independent pathways, such as angiopoietin-like 3 (ANGPTL3), apolipoprotein (apo) B, apoC-III and CETP, only ANGPTL3 offers the advantage of treating both HoFH and HeFH patients and showing relatively better preclinical and clinical efficacy in animal models and hypercholesterolemic individuals, respectively. While loss-of-LDLR-function mutations have been known for decades, gain-of-LDLR-function mutations have recently been identified in some individuals. The new information on gain of LDLR function, together with CRISPR-Cas9 genome/base editing technology to target LDLR and ANGPTL3, offers promise to HoFH and HeFH individuals who are at a higher risk of developing atherosclerotic cardiovascular disease (ASCVD).

GalNAc-Lipid nanoparticles enable non-LDLR dependent hepatic delivery of a CRISPR base editing therapy.

Lipid nanoparticles have demonstrated utility in hepatic delivery of a range of therapeutic modalities and typically deliver their cargo via low-density lipoprotein receptor-mediated endocytosis. For patients lacking sufficient low-density lipoprotein receptor activity, such as those with homozygous familial hypercholesterolemia, an alternate strategy is needed. Here we show the use of structure-guided rational design in a series of mouse and non-human primate studies to optimize a GalNAc-Lipid nanoparticle that allows for low-density lipoprotein receptor independent delivery. In low-density lipoprotein receptor-deficient non-human primates administered a CRISPR base editing therapy targeting the ANGPTL3 gene, the introduction of an optimized GalNAc-based asialoglycoprotein receptor ligand to the nanoparticle surface increased liver editing from 5% to 61% with minimal editing in nontargeted tissues. Similar editing was noted in wild-type monkeys, with durable blood ANGPTL3 protein reduction up to 89% six months post dosing. These results suggest that GalNAc-Lipid nanoparticles may effectively deliver to both patients with intact low-density lipoprotein receptor activity as well as those afflicted by homozygous familial hypercholesterolemia.