Bifunctional PEGylated exenatide-amylinomimetic hybrids to treat metabolic disorders: an example of long-acting dual hormonal therapeutics.

Peptide hybrids (phybrids) comprising covalently linked peptide hormones can leverage independent biological pathways for additive or synergistic metabolic benefits. PEGylation of biologics offers enhanced stability, duration, and reduced immunogenicity. These two modalities can be combined to produce long-acting therapeutics with dual pharmacology and enhanced efficacy. Compound 10 is composed of an exenatide (AC2993) analogue, AC3174, and an amylinomimetic, davalintide (AC2307), with an intervening 40 kD PEG moiety. It displayed dose-dependent and prolonged efficacy for glucose control and body weight reduction in rodents with superior in vitro and in vivo activities compared to those of a side-chain PEGylated phybrid 6. In diet-induced obese (DIO) rats, the weight-loss efficacy of 10 was similar to that of a combination of PEG-parents 3 and 4. A single dose of 10 elicited sustained body weight reduction in DIO rats for at least 21 days. Compound 10's terminal half-life of ~27 h should translate favorably to weekly dosing in humans.

Efficacy, safety, and tolerability of exenatide once weekly in patients with type 2 diabetes mellitus: an integrated analysis of the DURATION trials.

BACKGROUND AND AIM: Exenatide is a glucagon-like peptide-1 receptor agonist demonstrated to improve glycemic control with low hypoglycemia risk in patients with type 2 diabetes mellitus. The Diabetes Therapy Utilization: Researching Changes in A1C, Weight, and Other Factors Through Intervention With Exenatide Once Weekly (DURATION) program comprised 6 randomized, comparator-controlled, 24- to 30-week trials of exenatide once weekly (EQW), an extended-release formulation. This post hoc analysis pooled data from patients taking EQW across 6 trials to assess efficacy and safety in a large, varied patient population. MATERIALS AND METHODS: The intent-to-treat (ITT) population contained 1379 patients (baseline mean ± standard deviation glycated hemoglobin [HbA1c] levels of 8.4% ± 1.1%) who were treated with EQW over the course of 24 to 30 weeks. Changes from baseline in efficacy parameters for the ITT population and a completer population (1195 patients with ≥ 22 weeks of exposure) were evaluated. RESULTS: The ITT population experienced significant reductions from baseline (least-squares mean [95% CI]) in HbA1c levels (-1.4% [-1.5% to -1.4%]), fasting blood glucose levels (-36 mg/dL [-38.4 mg/dL to -33.8 mg/dL]), and body weight (-2.5 kg [-2.8 kg to -2.3 kg]) after 24 to 30 weeks of EQW treatment. Reductions in HbA1c and fasting blood glucose levels were observed across baseline HbA1c level strata; patients with higher baseline HbA1c levels experienced greater reductions. Treatment with EQW was associated with modest, significant reductions in blood pressure (systolic blood pressure, -2.8 mm Hg [-3.5 mm Hg to -2.1 mm Hg]; diastolic blood pressure, -0.8 mm Hg [-1.2 mm Hg to -0.4 mm Hg]), and fasting lipid levels (total cholesterol, -6.5 mg/dL [-8.2 mg/dL to -4.7 mg/dL]; low-density lipoprotein cholesterol, -3.9 mg/dL [5.3 mg/dL to -2.5 mg/dL]; and triglyceride [geometric least-squares mean percent change (95% CI)], -6% [-8% to -4%] levels). Similar reductions were observed in the completer population. Exenatide once weekly was generally well tolerated. Transient, mild-to-moderate gastrointestinal treatment-emergent adverse events and injection-site treatment-emergent adverse events were reported most frequently, but were seldom treatment limiting. No major hypoglycemic events were observed; minor hypoglycemic events occurred infrequently in patients not using a sulfonylurea. CONCLUSION: This post hoc analysis of > 1300 patients demonstrated that EQW was associated with significant reductions in HbA1c levels, body weight, blood pressure, and fasting lipid levels, with minimal hypoglycemia risk. Consistent with established safety profiles, EQW therapy was generally well tolerated. TRIAL REGISTRATION: www.ClinicalTrials.gov identifiers: NCT00308139, NCT00637273, NCT00641056, NCT00676338, NCT00877890, NCT01029886.

Effects of amylin and bupropion/naltrexone on food intake and body weight are interactive in rodent models.

Antagonism of opioid systems (e.g., with naltrexone) has been explored as an anti-obesity strategy, and is particularly effective when co-administered with dual inhibitors of dopamine and norepinephrine reuptake (e.g., bupropion). Previously, we demonstrated that amylin enhances the food intake lowering and weight loss effects of neurohormonal (e.g., leptin, cholecystokinin, melanocortins) and small molecule (e.g., phentermine, sibutramine) agents. Here, we sought to characterize the interaction of amylin with naltrexone/bupropion on energy balance. Wild-type and amylin knockout mice were similarly responsive to the food intake lowering effects of either naltrexone (1mg/kg, subcutaneous) or bupropion (50mg/kg, subcutaneous) suggesting that they act independently of amylinergic systems and could interact additively when given in combination with amylin. To test this, diet-induced obese rats were treated (for 11 days) with vehicle, rat amylin (50 µg/kg/d, infused subcutaneously), naltrexone/bupropion (1 and 20mg/kg, respectively by twice daily subcutaneous injection) or their combination. We found that amylin+naltrexone/bupropion combination therapy exerted additive effects to reduce cumulative food intake, body weight and fat mass. In a separate study, the effects of amylin and naltrexone/bupropion administered at the same doses (for 14 days) were compared to a pair-fed group. Although the combination and pair-fed groups lost a similar amount of body weight, rats treated with the combination lost 68% more fat and better maintained their lean mass. These findings support the strategy of combined amylin agonism with opioid and catecholaminergic signaling systems for the treatment of obesity.