ANGPTL8 Blockade With a Monoclonal Antibody Promotes Triglyceride Clearance, Energy Expenditure, and Weight Loss in Mice

Abstract

Angiopoietin-like protein (ANGPTL)8 is a negative regulator of lipoprotein lipase-mediated plasma triglyceride (TG) clearance. In this study, we describe a fully human monoclonal antibody (REGN3776) that binds monkey and human ANGPTL8 with high affinity. Inhibition of ANGPTL8 with REGN3776 in humanized ANGPTL8 mice decreased plasma TGs and increased lipoprotein lipase activity. Additionally, REGN3776 reduced body weight and fat content. The reduction in body weight was secondary to increased energy expenditure. Finally, single administration of REGN3776 normalized plasma TGs in dyslipidemic cynomolgus monkeys. In conclusion, we show that blockade of ANGPTL8 with monoclonal antibody strongly reduced plasma TGs in mice and monkeys. These data suggest that inhibition of ANGPTL8 may provide a new therapeutic avenue for the treatment of dyslipidemia with beneficial effects on body weight.

Figure 1.

REGN3776 reduces serum TG in Angptl8^hum/hum mice. Serum samples were collected from nonfasted male Angptl8^hum/hum mice (n = 5 per group) 7 days before (baseline) and at the indicated days following a single SC injection of REGN3776 or control antibody (10 mg/kg). Serum TG (a) and cholesterol (b) were measured enzymatically. Serum from each mouse collected 7 days after treatment with REGN3776 or control antibody was size fractionated by HPLC. TG (c) and cholesterol (d) were measured in each fraction. (e) Total (free plus antibody-bound) serum levels of human ANGPTL8 were measured by enzyme-linked immunosorbent assay. (f) Dose-dependent lowering of serum TGs by REGN3776 in chow-fed Angptl8^hum/hum mice measured 7 and 14 days after antibody administration. Values are mean ± standard error of the mean, except for the chromatograms, where only mean values are shown. Statistical analysis was conducted by a two-way analysis of variance with a Sidak correction posttest. **P < 0.01, ***P < 0.001, ****P < 0.0001.

Figure 2.

REGN3776 increases LPL activity and improves TG clearance in Angptl8^hum/hum mice. (a) Post-heparin plasma LPL and HL activity of chow-fed Angptl8^hum/hum mice treated with REGN3776 or control antibody (10 mg/kg, n=5/group). Post-heparin plasma was pooled and fractionated on a heparin column to separate HL and LPL, and TG hydrolase activity was measured. (b) Effect of REGN3776 treatment on plasma TG levels following a lipid tolerance test. Male Angptl8^hum/hum mice were treated with REGN3776 or control antibody (10 mg/kg, n = 5 per group) 4 days prior to the intravenous administration of Intralipid (2.5 µL/g of 20% Intralipid). Values are mean ± SEM. Statistical analysis was conducted by a Welch t test (a) and repeated measures two-way ANOVA with a Bonferroni’s posttest (b). **P < 0.01, ****P < 0.0001.

Figure 3.

Multiple dose administration of REGN3776 reduces serum TGs, body weight, and fat content and increases energy expenditure in Angptl8^hum/hum mice. Serum samples were collected from male Angptl8^hum/hum mice (n = 8 per group, 7 weeks old) in nonfasted state. Thereafter, the mice were placed on an HFHC diet. Seven days later, the mice received weekly SC injections of REGN3776 or control antibody (10 mg/kg). Serum samples were collected nonfasted 6 days after each injection. (a) Changes in TG measured over the course of the study. (b) Body weights were monitored weekly. (c) Body composition was measured at 15 weeks. Respiratory exchange ratio (RER) (d), energy expenditure (e), food intake (f), and locomotor activity (g) were measured during dark and light cycles in REGN3776 and control antibody-treated mice. All values are mean ± SEM. Statistical analysis was conducted by repeated measures two-way ANOVA with a Bonferroni correction posttest (a and b) or a Welch t test (c–g). *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.

Figure 4.

Single-dose administration of REGN3776 to spontaneous hypertriglyceridemic cynomolgus monkeys led to a reduction in plasma TGs and an increase in HDL-C. Baseline serum samples were collected at days −15, −7, and 0 from nonfasted animals. Eighteen monkeys were divided into three groups and administrated REGN3776 (3, 7, or 10 mg/kg). Saline was administered to six monkeys. Serum samples were collected at multiple days and analyzed for TGs (a), HDL-C (b), and LDL-C (c) and also represented as a percentage change from baseline: TGs (d), HDL-C (e), and LDL-C (f). All values are mean ± SEM. Statistical analyses were performed by repeated measures two-way ANOVA with a Sidak posttest. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.