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.

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.

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.