Lipoprotein(a) Particle Production as a Determinant of Plasma Lipoprotein(a) Concentration Across Varying Apolipoprotein(a) Isoform Sizes and Background Cholesterol-Lowering Therapy.

Background Elevated lipoprotein(a) (Lp(a)), a low-density lipoprotein-like particle bound to the polymorphic apolipoprotein(a) (apo(a)), may be causal for cardiovascular disease. However, the metabolism of Lp(a) in humans is poorly understood. Methods and Results We investigated the kinetics of Lp(a)-apo(a) and low-density lipoprotein-apoB-100 in 63 normolipidemic men. The fractional catabolic rate ( FCR ) and production rate PR ) were studied. Plasma apo(a) concentration was significantly and inversely associated with apo(a) isoform size ( r=-0.536, P<0.001) and apo(a) FCR ( r=-0.363, P<0.01), and positively with apo(a) PR ( r=0.877, P<0.001). There were no significant associations between the FCR s of apo(a) and low-density lipoprotein-apoB-100. Subjects with smaller apo(a) isoform sizes (≤22 kringle IV repeats) had significantly higher apo(a) PR ( P<0.05) and lower apo(a) FCR ( P<0.01) than those with larger sizes. Plasma apo(a) concentration was significantly associated with apo(a) PR ( r=0.930, P<0.001), but not with FCR ( r=-0.012, P>0.05) in subjects with smaller apo(a) isoform size. In contrast, both apo(a) PR and FCR were significantly associated with plasma apo(a) concentrations ( r=0.744 and -0.389, respectively, P<0.05) in subjects with larger isoforms. In multiple regression analysis, apo(a) PR and apo(a) isoform size were significant predictors of plasma apo(a) concentration independent of low-density lipoprotein-apoB-100 FCR and background therapy with atorvastatin and evolocumab. Conclusions In normolipidemic men, the plasma Lp(a) concentration is predominantly determined by the rate of production of Lp(a) particles, irrespective of apo(a) isoform size and background therapy with a statin and a proprotein convertase subtilisin-kexin type 9 inhibitor. Our findings underscore the importance of therapeutic targeting of the hepatic synthesis and secretion of Lp(a) particles. Lp(a) particle catabolism may only play a modest role in determining Lp(a) concentration in subjects with larger apo(a) isoform size. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 02189837.

New strategies for the development of lipid-lowering therapies to reduce cardiovascular risk.

The very high occurrence of cardiovascular events presents a major public health issue, because treatment remains suboptimal. Lowering LDL cholesterol (LDL-C) with statins or ezetimibe in combination with a statin reduces major adverse cardiovascular events. The cardiovascular risk reduction in relation to the absolute LDL-C reduction is linear for most interventions without evidence of attenuation or increase in risk at low LDL-C levels. Opportunities for innovation in dyslipidaemia treatment should address the substantial risk of lipid-associated cardiovascular events among patients optimally treated per guidelines but who cannot achieve LDL-C goals and who could benefit from additional LDL-C-lowering therapy or experience side effects of statins. Fresh approaches are needed to identify promising drug targets early and develop them efficiently. The Cardiovascular Round Table of the European Society of Cardiology (ESC) convened a workshop to discuss new lipid-lowering strategies for cardiovascular risk reduction. Opportunities to improve treatment approaches and the efficient study of new therapies were explored. Circulating biomarkers may not be fully reliable proxy indicators of the relationship between treatment effect and clinical outcome. Mendelian randomization studies may better inform development strategies and refine treatment targets before Phase 3. Trials should match the drug to appropriate lipid and patient profile, and guidelines may move towards a precision-based approach to individual patient management. Stakeholder collaboration is needed to ensure continued innovation and better international coordination of both regulatory aspects and guidelines. It should be noted that risk may also be addressed through increased attention to other risk factors such as smoking, hypertension, overweight, and inactivity.

Long-term treatment with evolocumab added to conventional drug therapy, with or without apheresis, in patients with homozygous familial hypercholesterolaemia: an interim subset analysis of the open-label TAUSSIG study.

BACKGROUND: Homozygous familial hypercholesterolaemia is a genetic disorder characterised by substantially raised LDL cholesterol, reduced LDL receptor function, xanthomas, and cardiovascular disease before age 20 years. Conventional therapy is with statins, ezetimibe, and apheresis. We aimed to assess the long-term safety and efficacy of the proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor evolocumab in a subset of patients with homozygous familial hypercholesterolaemia enrolled in an open-label, non-randomised phase 3 trial. METHODS: In this interim subset analysis of the TAUSSIG study, which was undertaken at 35 sites in 17 countries, we included patients aged 12 years or older with homozygous familial hypercholesterolaemia who were on stable LDL cholesterol-lowering therapy for at least 4 weeks; all patients received evolocumab 420 mg subcutaneously monthly, or if on apheresis every 2 weeks. Dosing could be increased to every 2 weeks after 12 weeks in patients not on apheresis. The primary outcome of the TAUSSIG study was treatment-emergent adverse events; secondary outcomes were the effects of evolocumab on LDL cholesterol and other lipids. We analysed patients on an intention-to-treat basis, and all statistical comparisons were done post hoc in this interim analysis. The TAUSSIG study is registered with ClinicalTrials.gov, number NCT01624142, and is ongoing. FINDINGS: 106 patients were included in this analysis, 34 receiving apheresis at study entry and 14 younger than 18 years. The first patient was enrolled on June 28, 2012, and the cutoff date for the analysis was Aug 13, 2015; mean follow-up was 1·7 years (SD 0·63). After 12 weeks, mean LDL cholesterol decreased from baseline by 20·6% (SD 24·4; mean absolute decrease 1·50 mmol/L [SD 1·92]); these reductions were maintained at week 48. 47 of 72 patients not on apheresis at study entry increased evolocumab dosing to every 2 weeks, with an additional mean reduction in LDL cholesterol of 8·3% (SD 13·0; mean absolute decrease 0·77 mmol/L [SD 1·38]; p=0·0001). In a post-hoc analysis, mean reductions in LDL cholesterol in patients on apheresis were significant at week 12 (p=0·0012) and week 48 (p=0·0032), and did not differ from reductions achieved in patients not on apheresis (p=0·38 at week 12 and p=0·09 at week 48). We noted a small reduction (median -7·7% [IQR -21·6 to 6·8]) in lipoprotein(a) at week 12 (p=0·0015), with some additional reduction at week 48 (-11·9% [-28·0 to 0·0]; p<0·0001). HDL cholesterol was increased by a mean of 7·6% (SD 18·1) at week 12 (p<0·0001) and 7·6% (SD 20·6) at week 48 (p=0·0007). Evolocumab was well tolerated; 82 (77%) patients reported treatment-emergent adverse events, which were mostly minor. The most common were nasopharyngitis (14 patients [13%]), influenza (13 [12%]), headache (11 [10%]), and upper respiratory tract infection (11 [10%]). Serious adverse events occurred in 18 (17%) patients, with the most common being cardiovascular events (four patients [4%]). There were no deaths and four positively adjudicated cardiovascular events, one (3%) among patients on apheresis and three (4%) among patients who did not receive apheresis. INTERPRETATION: Our interim results suggest that evolocumab is an effective additional option to reduce LDL cholesterol in patients with homozygous familial hypercholesterolaemia, with or without apheresis. FUNDING: Amgen.

PCSK9 inhibition-mediated reduction in Lp(a) with evolocumab: an analysis of 10 clinical trials and the LDL receptor's role.

Lipoprotein (a) [Lp(a)] is independently associated with CVD risk. Evolocumab, a monoclonal antibody (mAb) to proprotein convertase subtilisin/kexin type 9 (PCSK9), decreases Lp(a). The potential mechanisms were assessed. A pooled analysis of Lp(a) and LDL cholesterol (LDL-C) in 3,278 patients from 10 clinical trials (eight phase 2/3; two extensions) was conducted. Within each parent study, biweekly and monthly doses of evolocumab statistically significantly reduced Lp(a) at week 12 versus control (P < 0.001 within each study); pooled median (quartile 1, quartile 3) percent reductions were 24.7% (40.0, 3.6) and 21.7% (39.9, 4.2), respectively. Reductions were maintained through week 52 of the open-label extension, and correlated with LDL-C reductions [with and without correction for Lp(a)-cholesterol] at both time points (P < 0.0001). The effect of LDL and LDL receptor (LDLR) availability on Lp(a) cell-association was measured in HepG2 cells: cell-associated LDL fluorescence was reversed by unlabeled LDL and Lp(a). Lp(a) cell-association was reduced by coincubation with LDL and PCSK9 and reversed by adding PCSK9 mAb. These studies support that reductions in Lp(a) with PCSK9 inhibition are partly due to increased LDLR-mediated uptake. In most situations, Lp(a) appears to compete poorly with LDL for LDLR binding and internalization, but when LDLR expression is increased with evolocumab, particularly in the setting of low circulating LDL, Lp(a) is reduced.

Evolocumab (AMG 145) for primary hypercholesterolemia.

Evolocumab is a fully human monoclonal IgG2 antibody that inhibits proprotein convertase subtilisin/kexin type 9, a protein that targets LDL receptors for degradation and thereby reduces the liver's ability to remove LDL-C from the blood. In Phase II and III trials in more than 6000 subjects with primary hypercholesterolemia, evolocumab reduced LDL-C by 50-75% compared with placebo and by 35-45% compared with ezetimibe. Evolocumab reduced the proatherogenic lipid profile, including Lp(a), and modestly increased HDL-C and ApoA1. In subjects with homozygous familial hypercholesterolemia, evolocumab reduced LDL-C by 30%. Safety and tolerability of evolocumab was similar to that of placebo and ezetimibe. The ongoing FOURIER trial, anticipated to report in 2017, will provide definitive evidence on cardiovascular endpoints and additional long-term safety.

Inhibition of PCSK9 with evolocumab in homozygous familial hypercholesterolaemia (TESLA Part B): a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Homozygous familial hypercholesterolaemia is a rare, serious disorder caused by very low or absent plasma clearance of LDL, substantially raised LDL cholesterol, and accelerated development of cardiovascular disease. Conventional lipid-lowering treatments are modestly effective. Evolocumab, a monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9), reduced LDL cholesterol by 16% in a pilot study. We now report results with evolocumab in a randomised, double-blind, placebo-controlled phase 3 trial. METHODS: This randomised, double-blind, placebo-controlled phase 3 trial was undertaken at 17 sites in ten countries in North America, Europe, the Middle East, and South Africa. 50 eligible patients (aged ≥12 years) with homozygous familial hypercholesterolaemia, on stable lipid-regulating therapy for at least 4 weeks, and not receiving lipoprotein apheresis, were randomly allocated by a computer-generated randomisation sequence in a 2:1 ratio to receive subcutaneous evolocumab 420 mg or placebo every 4 weeks for 12 weeks. Randomisation was stratified by LDL cholesterol at screening (<11 mmol/L or ≥11 mmol/L) and implemented by a computerised interactive voice-response system. Patients, study personnel, and the funder were masked to treatment and to the efficacy results by the central laboratory not returning LDL cholesterol or any lipid results to the clinical sites after the baseline visit. The primary endpoint was percentage change in ultracentrifugation LDL cholesterol from baseline at week 12 compared with placebo, analysed by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT01588496. FINDINGS: Of the 50 eligible patients randomly assigned to the two treatment groups, 49 actually received the study drug and completed the study (16 in the placebo group and 33 in the evolocumab group). Compared with placebo, evolocumab significantly reduced ultracentrifugation LDL cholesterol at 12 weeks by 30·9% (95% CI -43·9% to -18·0%; p<0·0001). Treatment-emergent adverse events occurred in ten (63%) of 16 patients in the placebo group and 12 (36%) of 33 in the evolocumab group. No serious clinical or laboratory adverse events occurred, and no anti-evolocumab antibody development was detected during the study. INTERPRETATION: In patients with homozygous familial hypercholesterolaemia receiving stable background lipid-lowering treatment and not on apheresis, evolocumab 420 mg administered every 4 weeks was well tolerated and significantly reduced LDL cholesterol compared with placebo. FUNDING: Amgen Inc.

PCSK9 inhibition with evolocumab (AMG 145) in heterozygous familial hypercholesterolaemia (RUTHERFORD-2): a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Heterozygous familial hypercholesterolaemia is characterised by low cellular uptake of LDL cholesterol, increased plasma LDL cholesterol concentrations, and premature cardiovascular disease. Despite intensive statin therapy, with or without ezetimibe, many patients are unable to achieve recommended target levels of LDL cholesterol. We investigated the effect of PCSK9 inhibition with evolocumab (AMG 145) on LDL cholesterol in patients with this disorder. METHODS: This multicentre, randomised, double-blind, placebo-controlled trial was undertaken at 39 sites (most of which were specialised lipid clinics, mainly attached to academic institutions) in Australia, Asia, Europe, New Zealand, North America, and South Africa between Feb 7 and Dec 19, 2013. 331 eligible patients (18-80 years of age), who met clinical criteria for heterozygous familial hypercholesterolaemia and were on stable lipid-lowering therapy for at least 4 weeks, with a fasting LDL cholesterol concentration of 2·6 mmol/L or higher, were randomly allocated in a 2:2:1:1 ratio to receive subcutaneous evolocumab 140 mg every 2 weeks, evolocumab 420 mg monthly, or subcutaneous placebo every 2 weeks or monthly for 12 weeks. Randomisation was computer generated by the study sponsor, implemented by a computerised voice interactive system, and stratified by LDL cholesterol concentration at screening (higher or lower than 4·1 mmol/L) and by baseline ezetimibe use (yes/no). Patients, study personnel, investigators, and Amgen study staff were masked to treatment assignments within dosing frequency groups. The coprimary endpoints were percentage change from baseline in LDL cholesterol at week 12 and at the mean of weeks 10 and 12, analysed by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT01763918. FINDINGS: Of 415 screened patients, 331 were eligible and were randomly assigned to the four treatment groups: evolocumab 140 mg every 2 weeks (n=111), evolocumab 420 mg monthly (n=110), placebo every 2 weeks (n=55), or placebo monthly (n=55). 329 patients received at least one dose of study drug. Compared with placebo, evolocumab at both dosing schedules led to a significant reduction in mean LDL cholesterol at week 12 (every-2-weeks dose: 59·2% reduction [95% CI 53·4-65·1], monthly dose: 61·3% reduction [53·6-69·0]; both p<0·0001) and at the mean of weeks 10 and 12 (60·2% reduction [95% CI 54·5-65·8] and 65·6% reduction [59·8-71·3]; both p<0·0001). Evolocumab was well tolerated, with rates of adverse events similar to placebo. The most common adverse events occurring more frequently in the evolocumab-treated patients than in the placebo groups were nasopharyngitis (in 19 patients [9%] vs five [5%] in the placebo group) and muscle-related adverse events (ten patients [5%] vs 1 [1%]). INTERPRETATION: In patients with heterozygous familial hypercholesterolaemia, evolocumab administered either 140 mg every 2 weeks or 420 mg monthly was well tolerated and yielded similar and rapid 60% reductions in LDL cholesterol compared with placebo. FUNDING: Amgen Inc.

The role of Hath6, a newly identified shear-stress-responsive transcription factor, in endothelial cell differentiation and function.

The key regulators of endothelial differentiation that is induced by shear stress are mostly unclear. Human atonal homolog 6 (Hath6 or ATOH8) is an endothelial-selective and shear-stress-responsive transcription factor. In this study, we sought to elucidate the role of Hath6 in the endothelial specification of embryonic stem cells. In a stepwise human embryonic stem cell to endothelial cell (hESC-EC) induction system, Hath6 mRNA was upregulated synchronously with endothelial determination. Subsequently, gain-of-function and loss-of-function studies of Hath6 were performed using the hESC-EC induction model and endothelial cell lines. The overexpression of Hath6, which mimics shear stress treatment, resulted in an increased CD45(-)CD31(+)KDR(+) population, a higher tubular-structure-formation capacity and increased endothelial-specific gene expression. By contrast, the knockdown of Hath6 mRNA markedly decreased endothelial differentiation. Hath6 also facilitated the maturation of endothelial cells in terms of endothelial gene expression, tubular-structure formation and cell migration. We further demonstrated that the gene encoding eNOS is a direct target of Hath6 through a reporter system assay and western blot analysis, and that the inhibition of eNOS diminishes hESC-EC differentiation. These results suggest that eNOS plays a key role in linking Hath6 to the endothelial phenotype. Further in situ hybridization studies in zebrafish and mouse embryos indicated that homologs of Hath6 are involved in vasculogenesis and angiogenesis. This study provides the first confirmation of the positive impact of Hath6 on human embryonic endothelial differentiation and function. Moreover, we present a potential signaling pathway through which shear stress stimulates endothelial differentiation.

AMG 145, a monoclonal antibody against PCSK9, facilitates achievement of national cholesterol education program-adult treatment panel III low-density lipoprotein cholesterol goals among high-risk patients: an analysis from the LAPLACE-TIMI 57 trial (LDL-C assessment with PCSK9 monoclonal antibody inhibition combined with statin thErapy-thrombolysis in myocardial infarction 57).

OBJECTIVES: This study sought to define the ability of AMG 145, a monoclonal antibody directed against proprotein convertase subtilisin kexin type 9 (PCSK9), to enable subjects at high risk for major adverse cardiovascular events to achieve National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) parameters for low-density lipoprotein cholesterol (LDL-C) and other lipid goals. BACKGROUND: Many patients at high risk for adverse cardiovascular events are unable to achieve the NCEP-ATP III LDL-C goal of <70 mg/dl, even with high-potency statin therapy. METHODS: In 282 subjects from the LAPLACE-TIMI 57 (LDL-C Assessment with PCSK9 monoclonaL Antibody Inhibition Combined With Statin thErapy-Thrombolysis In Myocardial Infarction 57) trial at high risk according to NCEP-ATP III criteria, we compared the proportion of subjects achieving the NCEP-ATP III recommended LDL-C goal of <70 mg/dl across treatment arms. Other outcomes included the triple goals of LDL-C <70 mg/dl, non-high-density lipoprotein cholesterol (HDL-C) <100 mg/dl, and apolipoprotein B (ApoB) <80 mg/dl. RESULTS: During the dosing interval, more than 90% of subjects in both of the top dose groups every 2 weeks and every 4 weeks attained this lipid target over the dosing interval, with similar success rates for the triple lipid goal. CONCLUSIONS: PCSK9 inhibition with AMG 145 enables high-risk patients to achieve established lipid goals. If this therapy demonstrates efficacy for reducing cardiovascular events with a favorable safety profile in ongoing phase 3 trials, we believe it will have major public health implications.

Effect of the proprotein convertase subtilisin/kexin 9 monoclonal antibody, AMG 145, in homozygous familial hypercholesterolemia.

BACKGROUND: Homozygous familial hypercholesterolemia is a rare, serious disorder with a substantial reduction in low-density lipoprotein (LDL) receptor function, severely elevated LDL cholesterol, cardiovascular disease, and often death in childhood. Response to conventional drug therapies is modest. Monoclonal antibodies to proprotein convertase subtilisin/kexin 9 (PCSK9) reduce LDL cholesterol in heterozygous familial hypercholesterolemia. The effect in homozygous familial hypercholesterolemia is unknown and uncertain. We evaluated the efficacy and safety of AMG 145 in an open-label, single-arm, multicenter, dose-scheduling pilot study in patients with homozygous familial hypercholesterolemia. METHODS AND RESULTS: Eight patients with LDL receptor-negative or -defective homozygous familial hypercholesterolemia on stable drug therapy were treated with subcutaneous 420 mg AMG 145 every 4 weeks for ≥12 weeks, followed by 420 mg AMG 145 every 2 weeks for an additional 12 weeks. All patients completed both treatment periods. Mean change from baseline in LDL cholesterol at week 12 was -16.5% (range, 5.2% to -43.6%; P=0.0781) and -13.9% (range, 39.9% to -43.3%; P=0.1484) with 4- and 2-week dosing, respectively. No reduction was seen in the 2 receptor-negative patients. Over the treatment periods, mean±SD LDL cholesterol reductions in the 6 LDL receptor-defective patients were 19.3±16% and 26.3±20% with 4- and 2-week dosing, respectively (P=0.0313 for both values), ranging from 4% to 48% with 2-week dosing. No serious side effects were reported. CONCLUSION: This study demonstrates significant and dose-related LDL cholesterol lowering with a PCSK9 monoclonal antibody in homozygous familial hypercholesterolemia patients with defective LDL receptor activity but no reduction in those who were receptor negative.

Development and preliminary validation of a Function IndeX for Trauma (FIX-IT).

BACKGROUND: Assessing fracture healing in clinical trials is subjective. The new Function IndeX for Trauma (FIX-IT) score provides a simple, standardized approach to assess weight-bearing and pain in patients with lower extremity fractures. We conducted an initial validation of the FIX-IT score. METHODS: We conducted a cross-sectional study involving 50 patients with lower extremity fractures across different stages of healing to evaluate the reliability and preliminary validity of the FIX-IT score. Patients were independently examined by 2 orthopedic surgeons, 1 orthopedic fellow, 2 orthopedic residents and 2 research coordinators. Patients also completed the Short Form-36 version 2 (SF-36v2) questionnaire, and convergent validity was tested with the SF-36v2. RESULTS: For interrater reliability, the intraclass correlation coefficients ranged from 0.637 to 0.915. The overall interrater reliability for the total FIX-IT score was 0.879 (95% confidence interval 0.828-0.921). The correlations between the FIX-IT score and the SF-36 ranged from 0.682 to 0.770 for the physical component summary score, from 0.681 to 0.758 for the physical function subscale, and from 0.677 to 0.786 for the role-physical subscale. CONCLUSION: The FIX-IT score had high interrater agreement across multiple examiners. Moreover, FIX-IT scores correlate with the physical scores of the SF-36. Although additional research is needed to fully validate FIX-IT, our results suggest the potential for FIX-IT to be a reliable adjunctive clinician measure to evaluate healing in lower extremity fractures. LEVEL OF EVIDENCE: Diagnostic Study Level I.

CONTEXTE: Évaluer la guérison d'une fracture dans le cadre d'essais cliniques est un processus subjectif. Le nouveau score FIX-IT (pour Function IndeX for Trauma) constitue une approche simple et standardisée pour évaluer la mise en charge et la douleur chez les patients ayant subi une fracture d'un membre inférieur. Nous avons procédé à une validation initiale du score FIX-IT. MÉTHODES: Nous avons réalisé une étude transversale regroupant 50 patients qui ont subi une fracture d'un membre inférieur, à différents stades de la guérison, pour évaluer la fiabilité et la validité préliminaire du score FIX-IT. Les patients ont été examinés indépendamment par 2 chirurgiens orthopédistes, 1 chargé de cours en orthopédie, 2 médecins résidents en orthopédie et 2 coordonnateurs de recherche. Les patients ont aussi répondu au questionnaire SF-36v2 (Short Form-36 version 2) et la validité convergente a été vérifiée au moyen du SF-36v2. RÉSULTATS: En ce qui concerne la fiabilité interexaminateur, les coefficients de corrélation intraclasse ont varié de 0,637 à 0,915. La fiabilité interexaminateur pour le score FIX-IT total a été de 0,879 (intervalle de confiance de 95 % 0,828­0,921). Les corrélations entre le score FIX-IT et le SF-36 ont varié de 0,682 à 0,770 pour le score sommaire de la composante physique, de 0,681 à 0,758 pour la sous-échelle du fonctionnement physique et de 0,677 à 0,786 pour la sous-échelle du rôle physique. CONCLUSION: Le score FIX-IT a offert une concordance interexaminateur élevée entre les multiples examinateurs. De plus, les scores FIX-IT sont en corrélation avec les scores physiques obtenus au SF-36. Même s'il faudra approfondir la recherche pour valider complètement le score FIX-IT, nos résultats donnent à penser que cet indice pourrait être une mesure clinique d'appoint fiable pour évaluer la guérison des fractures de membres inférieurs. NIVEAU DE PREUVE: Étude diagnostique de niveau I.

Safety and effect of very low levels of low-density lipoprotein cholesterol on cardiovascular events.

Based on the cardiovascular (CV) outcomes data derived predominantly from 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor (statin) trials, guidelines have set low-density lipoprotein (LDL) cholesterol targets at successively lower levels over time. Recent data have demonstrated that more-intensive statin therapy (and, consequently, lower LDL cholesterol level) is more effective at reducing CV events than less-intensive statin therapy. Although the average LDL cholesterol level for a United States adult is 119 mg/dl, within the "normal" range (90 to 130 mg/dl) per the United States National Cholesterol Education Program-Adult Treatment Panel III guidelines, data from fetal studies, diet studies, contemporary hunter-gatherer populations, and other mammals have suggested that the "normal" physiologic range for LDL cholesterol in humans is likely 50 to 70 mg/dl. Low LDL cholesterol levels have been sporadically associated with an increased risk of cancer, hemorrhagic stroke, and other complications in population studies and clinical trials. However, statin clinical trials have generally not demonstrated correlations between on-treatment LDL cholesterol levels and safety. Clinical data have suggested a linear relation between LDL cholesterol lowering and CV risk reduction, supporting a favorable risk/benefit ratio for attaining very low levels of LDL cholesterol to minimize the risk of CV events. In conclusion, clinical trial evidence demonstrating the efficacy and safety of LDL cholesterol lowering to a very low level is essential to ascertain the benefits and risks in reducing the residual risk of vascular disease.

Low-density lipoprotein cholesterol-lowering effects of AMG 145, a monoclonal antibody to proprotein convertase subtilisin/kexin type 9 serine protease in patients with heterozygous familial hypercholesterolemia: the Reduction of LDL-C with PCSK9 Inhibition in Heterozygous Familial Hypercholesterolemia Disorder (RUTHERFORD) randomized trial.

BACKGROUND: Despite statin treatment, many patients with heterozygous familial hypercholesterolemia do not reach desired low-density lipoprotein cholesterol (LDL-C) targets. AMG 145, a fully human monoclonal antibody against proprotein convertase subtilisin/kexin type 9 (PCSK9) serine protease, demonstrated significant reductions in LDL-C in phase 1 studies. This phase 2, multicenter, double-blind, randomized, placebo-controlled, dose-ranging study evaluated the efficacy and safety of AMG 145 in heterozygous familial hypercholesterolemia patients. METHODS AND RESULTS: Patients with heterozygous familial hypercholesterolemia diagnosed by Simon Broome criteria with LDL-C ≥2.6 mmol/L (100 mg/dL) despite statin therapy with or without ezetimibe were randomized 1:1:1 to AMG 145 350 mg, AMG 145 420 mg, or placebo-administered subcutaneously every 4 weeks. The primary end point was percentage change from baseline in LDL-C at week 12. Of 168 patients randomized, 167 received investigational product and were included in the full analysis set (mean [SD] age, 50 [13] years; 47% female; 89% white; mean [SD] baseline LDL-C, 4.0 [1.1] mmol/L (156 [42] mg/dL)). At week 12, LDL-C reduction measured by preparative ultracentrifugation (least squares mean [standard error (SE)]) was 43 (3)% and 55 (3)% with AMG 145 350 mg and 420 mg, respectively, compared with 1 (3)% increase with placebo (P<0.001 for both dose groups). Serious adverse events (not considered treatment-related) occurred in 2 patients on AMG 145. CONCLUSIONS: AMG 145 administered every 4 weeks yielded rapid and substantial reductions in LDL-C in heterozygous familial hypercholesterolemia patients despite intensive statin use, with or without ezetimibe, with minimal adverse events and good tolerability. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01375751.

Treatment of anemia with darbepoetin alfa in heart failure.

Anemia is common in heart failure (HF) patients. A prespecified pooled analysis of 2 randomized, double-blind, placebo-controlled studies evaluated darbepoetin alfa (DA) in 475 anemic patients with HF (hemoglobin [Hb], 9.0-12.5 g/dL). DA was administered subcutaneously every 2 weeks and titrated to achieve and maintain a target Hb level of 14.0+/-1.0 g/dL. By week 27, mean (SD) Hb concentrations did not increase with placebo but increased with DA from 11.5 (0.7) to 13.3 (1.3) g/dL. Hazard ratios (HRs) for DA compared with placebo for all-cause death or first HF hospitalization (composite end point), all-cause death, and HF hospitalization by month 12 were 0.67 (95% confidence interval [CI], 0.44-1.03; P=.067), 0.76 (95% CI, 0.39-1.48; P=.419), and 0.66 (95% CI, 0.40-1.07; P=.093), respectively. Incidence of adverse events was similar in both groups. In post hoc analyses, improvement in the composite end point was significantly associated with the mean Hb change from baseline (adjusted HR, 0.40; P=.017) with DA treatment. There was no increased risk of all-cause mortality or first HF hospitalization with DA in patients with reduced renal function or elevated baseline B-type natriuretic peptide, a biomarker of worse HF. These results suggest that DA is well tolerated, corrects HF-associated anemia, and may have favorable effects on clinical outcomes.

The safety and tolerability of darbepoetin alfa in patients with anaemia and symptomatic heart failure.

AIMS: To assess the safety and tolerability of darbepoetin alfa (DA) in the treatment of anaemia in heart failure (HF). METHODS AND RESULTS: In this pooled analysis of three randomized, double-blind, placebo-controlled studies of anaemic [haemoglobin (Hb) < or =12.0 g/dL or < or =12.5 g/dL] symptomatic HF subjects, DA was administered subcutaneously once every 2 weeks and titrated to achieve and maintain a target Hb of 14.0 +/- 1.0 g/dL. In total, 516 subjects were randomized; 231 (44.8%) to placebo, 285 (55.2%) to DA. Darbepoetin alfa was well tolerated, with an adverse event (AE) profile similar to placebo. Most subjects (placebo, 85%; DA, 87%) experienced at least one AE. There was a lower incidence of serious AEs in the DA group (placebo, 43%; DA, 37%) with the most frequent being worsening HF (placebo, 19%; DA, 11%). Treatment-related AEs were reported for 9% and 12% in placebo and DA subjects, respectively. Fewer deaths were reported in DA group (6%) vs. placebo (8%). CONCLUSION: Darbepoetin alfa was well tolerated with an AE profile similar to placebo in HF subjects treated to a target Hb of 14.0 +/- 1.0 g/dL. Contrary to recent data in other patient populations, there was no evidence of increased risk of mortality or cardiovascular events.

Design of the Reduction of Events with Darbepoetin alfa in Heart Failure (RED-HF): a Phase III, anaemia correction, morbidity-mortality trial.

BACKGROUND: Patients with heart failure (HF) and anaemia have greater functional impairment, worse symptoms, increased rates of hospital admission, and a higher risk of death, compared with non-anaemic HF patients. Whether correcting anaemia can improve outcomes is unknown. OBJECTIVE: The Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF; Clinical Trials.gov NCT 003 58215) was designed to evaluate the effect of the long-acting erythropoietin-stimulating agent darbepoetin alfa on mortality and morbidity (and quality of life) in patients with HF and anaemia. METHODS: Approximately 2600 patients with New York Heart Association class II-IV, an ejection fraction < or =40%, and a haemoglobin (Hb) consistently < or =12.0 g/dL but > or =9.0 g/dL will be enrolled. Patients are randomized 1:1 to double-blind subcutaneous administration of darbepoetin alfa or placebo. Investigators are also blinded to Hb measurements and darbepoetin alfa is dosed to achieve an Hb concentration of 13.0 g/dL (but not exceeding 14.5 g/dL) with sham adjustments of the dose of placebo. The primary endpoint is the time to death from any cause or first hospital admission for worsening HF, whichever occurs first. The study will complete when approximately 1150 subjects experience a primary endpoint.

Randomized, double-blind, placebo-controlled study to evaluate the effect of two dosing regimens of darbepoetin alfa in patients with heart failure and anaemia.

AIMS: Anaemia is common in chronic heart failure (CHF) and associated with worse outcome. This randomized, double-blind, placebo-controlled study evaluated the effect of two darbepoetin alfa dosing regimens on haemoglobin (Hb) rate of rise and clinical effects in patients with CHF and anaemia. METHODS AND RESULTS: Patients with CHF (>or=3 months), left ventricular ejection fraction (LVEF)

Effect of darbepoetin alfa on exercise tolerance in anemic patients with symptomatic chronic heart failure: a randomized, double-blind, placebo-controlled trial.

OBJECTIVES: This study sought to investigate whether darbepoetin alfa, an erythropoiesis-stimulating protein (ESP), improves exercise capacity in patients with symptomatic chronic heart failure (CHF) and anemia. BACKGROUND: Anemia is common in patients with CHF. METHODS: In a multicenter, randomized, double-blind, placebo-controlled study, CHF patients with anemia (hemoglobin > or =9.0 to < or =12.0 g/dl) received subcutaneous placebo (n = 22) or darbepoetin alfa (n = 19) at a starting dose of 0.75 microg/kg every 2 weeks for 26 weeks. The primary end point was change in exercise tolerance from baseline to week 27 as measured by peak oxygen uptake (ml/min/kg body weight). Other end points included changes in absolute peak VO2 (ml/min), exercise duration, and health-related quality of life. RESULTS: Differences (95% confidence interval) in mean changes from baseline to week 27 between treatment groups were 1.5 g/dl (0.5 to 2.4) for hemoglobin concentration (p = 0.005), 0.5 ml/kg/min (-0.7 to 1.7) for peak VO2 (p = 0.40), 45 ml/min (-35 to 127) for absolute peak VO2 (p = 0.27), and 108 s (-11 to 228) for exercise duration (p = 0.075). Patients receiving darbepoetin alfa compared with placebo had an improvement in self-reported Patient's Global Assessment of Change (79% vs. 41%, p = 0.01) but no significant differences in the Kansas City Cardiomyopathy and Minnesota Living with Heart Failure Questionnaire scores. Darbepoetin alfa was well tolerated. CONCLUSIONS: In patients with symptomatic CHF and anemia, darbepoetin alfa increased and maintained hemoglobin concentrations and improved health-related quality of life. A trend toward increased exercise time but not peak VO2 was observed. (Impact of Darbepoetin Alfa on Exercise Tolerance and Left Ventricular Structure in Subjects With Symptomatic Congestive Heart Failure (CHF) and Anemia; http://clinicaltrials.gov/ct/show/NCT00117234?order = 1; NCT00117234).

A novel interleukin-17 receptor-like protein identified in human umbilical vein endothelial cells antagonizes basic fibroblast growth factor-induced signaling.

We have previously utilized a combination of high throughput sequencing and genome-wide microarray profiling analyses to identify novel cell-surface proteins expressed in human umbilical vein endothelial cells. One gene identified by this approach encodes a type I transmembrane receptor that shares sequence homology with the intracellular domain of members of the interleukin-17 (IL-17) receptor family. Real-time quantitative PCR and Northern analyses revealed that this gene is highly expressed in human umbilical vein endothelial cells and in several highly vascularized tissues such as kidney, colon, skeletal muscle, heart, and small intestine. In addition, we also found that it is also highly expressed in the ductal epithelial cells of human salivary glands, seminal vesicles, and the collecting tubules of the kidney by in situ hybridization. This putative receptor, which we have termed human SEF (hSEF), is also expressed in a variety of breast cancer tissues. In co-immunoprecipitation assays, this receptor is capable of forming homomeric complexes and can interact with fibroblast growth factor (FGF) receptor 1. Overexpression of this receptor inhibits FGF induction of an FGF-responsive reporter gene in human 293T cells. This appears to occur as a result of specific inhibition of p42/p44 ERK in the absence of upstream MEK inhibition. This inhibitory effect is dependent upon a functional intracellular domain since deletion mutants missing the IL-17 receptor-like domain lack this inhibitory effect. These findings are consistent with the recent discovery of the zebrafish homologue, Sef (similar expression to fgf genes), which specifically antagonizes FGF signaling when ectopically expressed in zebrafish or Xenopus laevis embryos. Based on sequence and functional similarities, this novel IL-17 receptor homologue represents a potential human SEF and is likely to play critical roles in endothelial or epithelial functions such as proliferation, migration, and angiogenesis.