Preclinical, randomized phase 1, and compassionate use evaluation of REGN4461, a leptin receptor agonist antibody for leptin deficiency

Deficiency in the adipose-derived hormone leptin or leptin receptor signaling causes class 3 obesity in individuals with genetic loss-of-function mutations in leptin or its receptor LEPR and metabolic and liver disease in individuals with hypoleptinemia secondary to lipoatrophy such as in individuals with generalized lipodystrophy. Therapies that restore leptin-LEPR signaling may resolve these metabolic sequelae. We developed a fully human monoclonal antibody (mAb), REGN4461 (mibavademab), that activates the human LEPR in the absence or presence of leptin. In obese leptin knockout mice, REGN4461 normalized body weight, food intake, blood glucose, and insulin sensitivity. In a mouse model of generalized lipodystrophy, REGN4461 alleviated hyperphagia, hyperglycemia, insulin resistance, dyslipidemia, and hepatic steatosis. In a phase 1, randomized, double-blind, placebo-controlled two-part study, REGN4461 was well tolerated with an acceptable safety profile. Treatment of individuals with overweight or obesity with REGN4461 decreased body weight over 12 weeks in those with low circulating leptin concentrations (<8 ng/ml) but had no effect on body weight in individuals with higher baseline leptin. Furthermore, compassionate-use treatment of a single patient with atypical partial lipodystrophy and a history of undetectable leptin concentrations associated with neutralizing antibodies to metreleptin was associated with noteable improvements in circulating triglycerides and hepatic steatosis. Collectively, these translational data unveil an agonist LEPR mAb that may provide clinical benefit in disorders associated with relatively low leptin concentrations.

Symptoms and Dietary Impact in Hypertriglyceridemia-Associated Pancreatitis: Development and Content Validity of Two New Measures

BACKGROUND

Severe hypertriglyceridemia (sHTG) is a rare condition, complicated by episodes of acute pancreatitis (AP), which can cause pain and/or life-threatening multi-organ dysfunction. Currently, there are no disease-specific patient-reported outcome (PRO) measures evaluating symptoms or dietary impact for this condition.

OBJECTIVE

The objective of this study was to explore patient-reported symptoms and impacts of sHTG and AP and develop new measures to capture the symptoms and dietary impacts of this condition using patient language.

METHODS

In-depth, semi-structured concept elicitation interviews were conducted with 12 US-based participants to explore their experience and identify key symptoms and impact on dietary behavior, both during and between episodes of AP. Participants had a range of AP severity with a previous triglyceride reading > 1000 mg/dL, and at least one attack of AP within the last 12 months. Transcripts were coded using thematic analysis.

RESULTS

Qualitative data analysis revealed the substantial burden of AP associated with sHTG. Participants reported experiencing symptoms, especially abdominal pain, both during and between attacks of AP, and discussed considerable diet changes to prevent or minimize future attacks. A conceptual model was refined, based on patient input, and reviewed by clinical experts to determine key concepts for inclusion within two PRO measures, one evaluating symptoms and another evaluating impact on dietary behavior. Items were drafted using patient-derived language. A 19-item symptoms measure [Hypertriglyceridemia and Acute Pancreatitis Symptom Scale (HAP-SS)] and a 6-item dietary impact measure (Hypertriglyceridemia and Acute Pancreatitis Dietary Behavior (HAP-DB) measure) were developed, both with a 24-h recall period.

CONCLUSIONS

The qualitative analysis confirmed the substantial burden of AP associated with sHTG. This research resulted in development of two disease-specific PRO measures for use during and between attacks of AP. These measures are being utilized in a clinical trial, which will confirm content, structure, and psychometric properties.

Inhibition of Angiopoietin-Like Protein 3 With a Monoclonal Antibody Reduces Triglycerides in Hypertriglyceridemia

Supplemental Digital Content is available in the text.

Background:

Hypertriglyceridemia is associated with increased cardiovascular risk and may be caused by impaired lipoprotein clearance. Angiopoietin-like protein 3 (ANGPTL3) inhibits lipoprotein lipase activity, increasing triglycerides and other lipids. Evinacumab, an ANGPTL3 inhibitor, reduced triglycerides in healthy human volunteers and in homozygous familial hypercholesterolemic individuals. Results from 2 Phase 1 studies in hypertriglyceridemic subjects are reported here.

Methods:

Subjects with triglycerides >150 but ≤450 mg/dL and low-density lipoprotein cholesterol ≥100 mg/dL (n=83 for single ascending dose study [SAD]; n=56 for multiple ascending dose study [MAD]) were randomized 3:1 to evinacumab:placebo. SAD subjects received evinacumab subcutaneously at 75/150/250 mg, or intravenously at 5/10/20 mg/kg, monitored up to day 126. MAD subjects received evinacumab subcutaneously at 150/300/450 mg once weekly, 300/450 mg every 2 weeks, or intravenously at 20 mg/kg once every 4 weeks up to day 56 with 6 months of follow-up. The primary outcomes were incidence and severity of treatment-emergent adverse events. Efficacy analyses included changes in triglycerides and other lipids over time.

Results:

In the SAD, 32 (51.6%) versus 9 (42.9%) subjects on evinacumab versus placebo reported treatment-emergent adverse events. In the MAD, 21 (67.7%) versus 9 (75.0%) subjects on subcutaneously evinacumab versus placebo and 6 (85.7%) versus 1 (50.0%) on intravenously evinacumab versus placebo reported treatment-emergent adverse events. No serious treatment-emergent adverse events or events leading to death or treatment discontinuation were reported. Elevations in alanine aminotransferase (7 [11.3%] SAD), aspartate aminotransferase (4 [6.5%] SAD), and creatinine phosphokinase (2 [3.2%) SAD, 1 [14.3%] MAD) were observed with evinacumab (none in the placebo groups), which were single elevations and were not dose-related. Dose-dependent reductions in triglycerides were observed in both studies, with maximum reduction of 76.9% at day 3 with 10 mg/kg intravenously (P<0.0001) in the SAD and of 83.1% at day 2 with 20 mg/kg intravenously once every 4 weeks (P=0.0003) in the MAD. Significant reductions in other lipids were observed with most evinacumab doses versus placebo.

Conclusion:

Evinacumab was well-tolerated in 2 Phase 1 studies. Lipid changes in hypertriglyceridemic subjects were similar to those observed with ANGPTL3 loss-of-function mutations. Because the latter is associated with reduced cardiovascular risk, ANGPTL3 inhibition may improve clinical outcomes.

Clinical Trial Registration:

https://www.clinicaltrials.gov. Unique identifiers: NCT01749878 and NCT02107872.

Effects of anacetrapib on plasma lipids in specific patient subgroups in the DEFINE (Determining the Efficacy and Tolerability of CETP INhibition with AnacEtrapib) trial

BACKGROUND

In the Determining the Efficacy and Tolerability of cholesteryl ester transfer protein (CETP) INhibition with AnacEtrapib (DEFINE) trial, anacetrapib added to statin produced robust low-density lipoprotein cholesterol (LDL-C)-lowering and high-density lipoprotein cholesterol (HDL-C)-raising vs placebo in patients with coronary heart disease (CHD). Predictors of the degree of LDL-C and HDL-C responses to anacetrapib, however, are poorly understood.

OBJECTIVE

Lipid effects of anacetrapib in patient subgroups within the DEFINE trial (clinicaltrials.gov: NCT00685776) are reported.

METHODS

The percent of placebo-corrected changes from baseline for LDL-C (estimated by Friedewald calculation [Fc-LDL-C]) and HDL-C after 24 weeks of anacetrapib 100 mg/day were compared among patients by age, gender, race, diabetes status, type of concomitant statin with or without other lipid therapies, and baseline HDL-C, Fc-LDL-C, and triglyceride (TG) levels.

RESULTS

Percent decreases in Fc-LDL-C and increases in HDL-C with anacetrapib were similar (magnitude of difference generally <1/5 of the overall treatment effect) across subgroups by age, gender, diabetes status, lipid-modifying regimen, and baseline Fc-LDL-C, HDL-C, or TG. On the other hand, anacetrapib effects on Fc-LDL-C (-24% vs -41%) and HDL-C (+75% vs +139%) appeared to be less in black vs white patients, respectively.

CONCLUSION

Effects of anacetrapib on Fc-LDL-C and HDL-C were generally comparable across subgroups, including being relatively independent of baseline Fc-LDL-C, HDL-C, or TG levels. The clinical impact of the lipid-modifying effects of anacetrapib is being evaluated in the cardiovascular disease outcomes trial, Randomized EValuation of the Effects of Anacetrapib though Lipid-modification (REVEAL).

Recipes for creating animal models of diabetic cardiovascular disease

For more than 50 years, investigators have unsuccessfully tried to recreate in experimental animals the cardiovascular complications of diabetes seen in humans. In particular, accelerated atherosclerosis and dilated cardiomyopathy, the major causes of mortality in patients with diabetes, have been conspicuously absent in many mouse models of the disease. Under the auspices of the NIH, the Animal Models of Diabetic Complications Consortium has worked to address this issue. This effort has focused on the development of mouse models because of the high level of genomic information available and the many well-developed genetic manipulations that may be performed in mice. Importantly, the consortium has also worked to standardize many methods to assess metabolic and cardiovascular end points for measurement of the diabetic state and its macrovascular complications. Finally, for maximum benefits from these animal models in the study of atherosclerosis and of other diabetic complications, the consortium has created a system for sharing both the animal models and the accumulated phenotypic data with the greater scientific community.

Found in translation

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Localization of atherosclerosis susceptibility loci to chromosomes 4 and 6 using the Ldlr knockout mouse model

Atherosclerosis is a complex disease resulting from the interaction of multiple genes. We have used the Ldlr knockout mouse model in an interspecific genetic cross to map atherosclerosis susceptibility loci. A total of 174 (MOLF/Ei x B6.129S7-Ldlr(tm1Her)) x C57BL/6J-Ldlr(tm1Her) backcross mice, homozygous for the Ldlr null allele, were fed a Western-type diet for 3 months and then killed for quantification of aortic lesions. A genome scan was carried out by using DNA pools and microsatellite markers spaced at approximately 18-centimorgan intervals. Quantitative trait locus analysis of individual backcross mice confirmed linkages to chromosomes 4 (Athsq1, logarithm of odds = 6.2) and 6 (Athsq2, logarithm of odds = 6.7). Athsq1 affected lesions in females only whereas Athsq2 affected both sexes. Among females, the loci accounted for approximately 50% of the total variance of lesion area. The susceptible allele at Athsq1 was derived from the MOLF/Ei genome whereas the susceptible allele at Athsq2 was derived from C57BL/6J. Inheritance of susceptible alleles at both loci conferred a 2-fold difference in lesion area, suggesting an additive effect of Athsq1 and Athsq2. No associations were observed between the quantitative trait loci and levels of plasma total cholesterol, high density lipoprotein cholesterol, non-high density lipoprotein cholesterol, insulin, or body weight. We provide strong evidence for complex inheritance of atherosclerosis in mice with elevated plasma low density lipoprotein cholesterol and show a major influence of nonlipoprotein-related factors on disease susceptibility. Athsq1 and Athsq2 represent candidate susceptibility loci for human atherosclerosis, most likely residing on chromosomes 1p36--32 and 12p13--12, respectively.

Sulindac inhibits neointimal formation after arterial injury in wild-type and apolipoprotein E-deficient mice

Neointimal hyperplasia is a critical component of restenosis, a major complication of angioplasty and related therapeutic procedures. We studied the effects of hyperlipidemia and the nonsteroidal anti-inflammatory drugs, aspirin (acetyl-salicylic acid; ASA), and sulindac, on neointimal formation in a mouse femoral arterial injury model. At 2 months of age, normolipidemic, wild-type (WT), and hyperlipidemic, apolipoprotein E-deficient (apoE-/-) mice were divided into three treatment groups: Western-type diet (WD), WD + ASA (200 mg/kg food), and WD + sulindac (300 mg/kg food). After 1 week, mice underwent arterial injury and treatments were maintained for 4 weeks. Histomorphometry of the injured arteries showed striking effects of plasma cholesterol levels and drug treatment on neointimal hyperplasia. In the WD or WD + ASA groups, apoE-/- mice had twice the neointimal area than WT mice ( approximately 30,000 vs. 13,000 microm(2) per section; P < 0.0001). Compared with ASA or WD alone, sulindac treatment resulted in approximately 70% (P = 0.0001) and 50% (P = 0.01) reductions in the neointimal area in apoE-/- and WT mice, respectively. ASA, at a dose sufficient to inhibit platelet aggregation, did not affect neointimal formation in mice of either genotype. Evidence of macrophages was noted in the lesions of apoE-/- mice in the WD and WD + ASA groups, but remarkably, none was detectable with sulindac treatment, despite hyperlipidemia, suggesting early steps in the response to injury were abrogated. These results demonstrate sulindac reduces neointimal formation in both normolipidemic and hyperlipidemic settings and raise the possibility that similar benefits may be obtained in patients undergoing angioplasty and related procedures.