Development of a long-acting relaxin analogue, LY3540378, for treatment of chronic heart failure.

BACKGROUND AND PURPOSE: Chronic heart failure, a progressive disease with limited treatment options currently available, especially in heart failure with preserved ejection fraction (HFpEF), represents an unmet medical need as well as an economic burden. The development of a novel therapeutic to slow or reverse disease progression would be highly impactful to patients and society. Relaxin-2 (relaxin) is a human hormone regulating cardiovascular, renal, and pulmonary adaptations during pregnancy. A short-acting recombinant relaxin, Serelaxin, demonstrated short-term heart failure symptom relief and biomarker improvement in acute heart failure trials. Here, we present the development of a long-acting relaxin analogue to be tested in the treatment of chronic heart failure. EXPERIMENTAL APPROACH: LY3540378 is a long-acting protein therapeutic composed of a human relaxin analogue and a serum albumin-binding VHH domain. KEY RESULTS: LY3540378 is a potent agonist of the relaxin family peptide receptor 1 (RXFP1) and maintains selectivity against RXFP2/3/4 comparable to native relaxin. The half-life of LY3540378 in preclinical species is extended through high affinity binding of the albumin-binding VHH domain to serum albumin. When tested in a single dose administration, LY3540378 elicited relaxin-mediated pharmacodynamic responses, such as reduced serum osmolality and increased renal blood flow in rats. In an isoproterenol-induced cardiac hypertrophy mouse model, treatment with LY3540378 significantly reduced cardiac hypertrophy and improved isovolumetric relaxation time. In a monkey cardiovascular safety study, there were no adverse observations from administration of LY3540378. CONCLUSION AND IMPLICATIONS: LY3540378 demonstrated to be a suitable clinical development candidate, and is progressing in clinical trials.

Pharmacological Evaluation of a Pegylated Urocortin-1 Peptide in Experimental Autoimmune Disease Models.

Urocortin-1 (UCN1) is a member of the corticotropin releasing hormone (CRH) family of peptides that acts through CRH-receptor 1 (CRHR1) and CRH-receptor 2 (CRHR2). UCN1 can induce the adrenocorticotropin hormone and downstream glucocorticoids through CRHR1 and promote beneficial metabolic effects through CRHR2. UCN1 has a short half-life and has been shown to improve experimental autoimmune disease. A pegylated UCN1 peptide (PEG-hUCN1) was generated to extend half-life and was tested in multiple experimental autoimmune disease models and in healthy mice to determine effects on corticosterone induction, autoimmune disease, and glucocorticoid induced adverse effects. Cardiovascular effects were also assessed by telemetry. PEG-hUCN1 demonstrated a dose dependent 4-6-fold elevation of serum corticosterone and significantly improved autoimmune disease comparable to prednisolone in several experimental models. In healthy mice, PEG-hUCN1 showed less adverse effects compared with corticosterone treatment. PEG-hUCN1 peptide induced an initial 30% reduction in blood pressure that was followed by a gradual and sustained 30% increase in blood pressure at the highest dose. Additionally, an adeno-associated viral 8 (AAV8) UCN1 was used to assess adverse effects of chronic elevation of UCN1 in wild type and CRHR2 knockout mice. Chronic UCN1 expression by an AAV8 approach in wild type and CRHR2 knockout mice demonstrated an important role of CRHR2 in countering the adverse metabolic effects of elevated corticosterone from UCN1. Our findings demonstrate that PEG-hUCN1 shows profound effects in treating autoimmune disease with an improved safety profile relative to corticosterone and that CRHR2 activity is important in metabolic regulation. SIGNIFICANCE STATEMENT: This study reports the generation and characterization of a pegylated UCN1 peptide and the role of CRHR2 in UCN1-induced metabolic effects. The potency/selectivity, pharmacokinetic properties, pharmacodynamic effects, and efficacy in four autoimmune models and safety profiles are presented. This pegylated UCN1 shows potential for treating autoimmune diseases with reduced adverse effects compared to corticosterone treatment. Continuous exposure to UCN1 through an AAV8 approach demonstrates some glucocorticoid mediated adverse metabolic effects that are exacerbated in the absence of the CRHR2 receptor.

A selective GPR40 (FFAR1) agonist LY2881835 provides immediate and durable glucose control in rodent models of type 2 diabetes.

LY2881835 is a selective, potent, and efficacious GPR40 agonist. The objective of the studies described here was to examine the pharmacological properties of LY2881835 in preclinical models of T2D. Significant increases in insulin secretion were detected when LY2881835 was tested in primary islets from WT mice but not in islets from GPR40 KO mice. Furthermore, LY2881835 potentiated glucose stimulated insulin secretion in normal lean mice. Acute administration of LY2881835 lowered glucose during OGTTs in WT mice but not in GPR40 KO mice. These findings demonstrate that LY2881835 induces GPR40-mediated activity ex vivo and in vivo. LY2881835 was administered orally at 10 mg/kg to diet-induced obese (DIO) mice (an early model of T2D due to insulin resistance) for 14 days. Statistically significant reductions in glucose were seen during OGTTs performed on days 1 and 15. When a study was done for 3 weeks in Zucker fa/fa rats, a rat model of insulin resistance, normalization of blood glucose levels equivalent to those seen in lean rats was observed. A similar study was performed in streptozotocin (STZ)-treated DIO mice to explore glucose control in a late model of T2D. In this model, pancreatic insulin content was reduced ~80% due to STZ-treatment plus the mice were insulin resistant due to their high fat diet. Glucose AUCs were significantly reduced during OGTTs done on days 1, 7, and 14 compared to control mice. In conclusion, these results demonstrate that LY2881835 functions as a GPR40-specific insulin secretagogue mediating immediate and durable glucose control in rodent models of early- and late-stage T2D.

A Novel Nociceptin Receptor Antagonist LY2940094 Inhibits Excessive Feeding Behavior in Rodents: A Possible Mechanism for the Treatment of Binge Eating Disorder.

Nociceptin/orphanin FQ (N/OFQ), a 17 amino acid peptide, is the endogenous ligand of the ORL1/nociceptin-opioid-peptide (NOP) receptor. N/OFQ appears to regulate a variety of physiologic functions including stimulating feeding behavior. Recently, a new class of thienospiro-piperidine-based NOP antagonists was described. One of these molecules, LY2940094 has been identified as a potent and selective NOP antagonist that exhibited activity in the central nervous system. Herein, we examined the effects of LY2940094 on feeding in a variety of behavioral models. Fasting-induced feeding was inhibited by LY2940094 in mice, an effect that was absent in NOP receptor knockout mice. Moreover, NOP receptor knockout mice exhibited a baseline phenotype of reduced fasting-induced feeding, relative to wild-type littermate controls. In lean rats, LY2940094 inhibited the overconsumption of a palatable high-energy diet, reducing caloric intake to control chow levels. In dietary-induced obese rats, LY2940094 inhibited feeding and body weight regain induced by a 30% daily caloric restriction. Last, in dietary-induced obese mice, LY2940094 decreased 24-hour intake of a high-energy diet made freely available. These are the first data demonstrating that a systemically administered NOP receptor antagonist can reduce feeding behavior and body weight in rodents. Moreover, the hypophagic effect of LY2940094 is NOP receptor dependent and not due to off-target or aversive effects. Thus, LY2940094 may be useful in treating disorders of appetitive behavior such as binge eating disorder, food choice, and overeating, which lead to obesity and its associated medical complications and morbidity.

Fibroblast growth factor 21 corrects obesity in mice.

Fibroblast growth factor 21 (FGF21) is a metabolic regulator that provides efficient and durable glycemic and lipid control in various animal models. However, its potential to treat obesity, a major health concern affecting over 30% of the population, has not been fully explored. Here we report that systemic administration of FGF21 for 2 wk in diet-induced obese and ob/ob mice lowered their mean body weight by 20% predominantly via a reduction in adiposity. Although no decrease in total caloric intake or effect on physical activity was observed, FGF21-treated animals exhibited increased energy expenditure, fat utilization, and lipid excretion, reduced hepatosteatosis, and ameliorated glycemia. Transcriptional and blood cytokine profiling studies revealed effects consistent with the ability of FGF21 to ameliorate insulin and leptin resistance, enhance fat oxidation and suppress de novo lipogenesis in liver as well as to activate futile cycling in adipose. Overall, these data suggest that FGF21 exhibits the therapeutic characteristics necessary for an effective treatment of obesity and fatty liver disease and provides novel insights into the metabolic determinants of these activities.

Assessment of diet-induced obese rats as an obesity model by comparative functional genomics.

OBJECTIVE: We applied a comparative functional genomics approach to evaluate whether diet-induced obese (DIO) rats serve as an effective obesity model. METHODS AND PROCEDURES: Gene-expression profiles of epididymal fat from DIO and lean rats were generated using microarrays and compared with the published array data of obese and non-obese human subcutaneous adipocytes. RESULTS: Caloric intake and fuel efficiency were significantly higher in DIO rats, which resulted in increased body weight and adiposity. Circulating glucose, cholesterol, triglyceride, insulin, and leptin levels in DIO rats were significantly higher than those in the lean controls. DIO rats also exhibited impaired insulin sensitivity. A direct comparison of gene-expression profiles from DIO and lean rats and those from obese and non-obese humans revealed that global gene-expression patterns in DIO rat fat resemble those of obese human adipocytes. Differentially expressed genes between obese and non-obese subjects in both human and rat studies were identified and associated with biological pathways by mapping genes to Gene Ontology (GO) categories. Immune response-related genes and angiogenesis-related genes exhibited significant upregulation in both obese humans and DIO rats when compared with non-obese controls. However, genes in fatty acid metabolism and oxidation exhibited a broad downregulation only in obese human adipocytes but not in DIO rat epididymal fat. DISCUSSION: Our study based on gene-expression profiling suggested that DIO rats in general represent an appropriate obesity model. However, the discrepancies in gene-expression alterations between DIO rats and obese humans, particularly in the metabolic pathways, may explain the limitations of using DIO rodent models in obesity research and drug discovery.

Diet-induced changes in stearoyl-CoA desaturase 1 expression in obesity-prone and -resistant mice.

OBJECTIVE: To investigate stearoyl-coenzyme A desaturase (SCD) 1 expression in obesity-prone C57BL/6 mice and in obesity-resistant FVB mice to explore the relationship of SCD1 expression and susceptibility to diet-induced obesity. RESEARCH METHODS AND PROCEDURES: Nine-week-old C57BL/6 and FVB mice were fed either a high- or low-fat diet for 8 weeks. Body weight and body composition were measured before and at weeks 4 and 8 of the study. Energy expenditure was measured at weeks 1 and 5 of the study. Hepatic SCD1 mRNA was measured at 72 hours and at the end of study. Plasma leptin and insulin concentrations were measured at the end of study. RESULTS: When C57BL/6 mice were switched to a calorie-dense high-fat diet, animals gained significantly more body weight than those maintained on a low-calorie density diet primarily due to increased fat mass accretion. Fat mass continued to accrue throughout 8 weeks of study. Increased calorie intake did not account for all weight gain. On the high-fat diet, C57BL/6 mice decreased their energy expenditure when compared with mice fed a low-fat diet. In response to 8 weeks of a high-fat diet, SCD1 gene expression in liver increased >2-fold. In contrast, feeding a high-fat diet did not change body weight, energy expenditure, or SCD1 expression in FVB mice. DISCUSSION: Our study showed that a high-fat hypercaloric diet increased body adiposity first by producing hyperphagia and then by decreasing energy expenditure of mice susceptible to diet-induced obesity. Consumption of a high-fat diet in species predisposed to obesity selectively increased SCD1 gene expression in liver.