13 research outputs found
PK profile of orally dosed peptides in monkeys.
<p>[Leu<sup>14</sup>]exenatide-ABD (▾) and [Leu<sup>14</sup>]exenatide-ABP (▿), n = 3. Data are presented as mean ± SEM.</p
<i>In Vitro</i> Activity, Metabolic Stability, and Plasma Glucose in OGTT.
<p>Stability results (measured as plasma AUC 0–5 h; pancreatin mix AUC 0–2 h)) are expressed as a percentage of peptide remaining versus stable control peptide ± SEM. Replicates within each assay n = 3, except for exenatide and [Leu<sup>14</sup>]exenatide-ABP where n = 2.</p
Four-week chronic dosing of peptides in diabetic <i>Lep<sup>ob/ob</sup></i> Mice.
<p>(A) effects on HbA1c (B) effects on body weight and (C) effects on food intake. Vehicle (□), [Leu<sup>14</sup>]exenatide-ABD (▾) and exenatide (▪). Data are presented as mean ± SEM, n = 10. *p<0.05 vs. vehicle, #p<0.05 vs. exenatide infusion by ANOVA with Tukey’s test.</p
Functional activity at the GLP-1 receptor.
<p>GLP-1 (7–36) (▪), [Leu<sup>14</sup>]exenatide-ABD (▾) and [Leu<sup>14</sup>]exenatide-ABP (▿). GLP-1 (7–36) was used as a reference standard in the assay. The assay was run in quadruplicates and data are presented as mean ± SD. Abbreviations: Fluorescence (F).</p
PK profile of intravenously dosed peptides in rats and monkeys.
<p>(A) rats, n = 3–4 and (B) monkeys, n = 3. Exenatide (▪), [Leu<sup>14</sup>]exenatide-ABD (▾) and [Leu<sup>14</sup>]exenatide-ABP (▿). Data are presented as mean ± SEM.</p
Binding Constants for Albumin Interactions at 25°C.
<p>The number in parentheses represents the standard deviation in the last significant digit.</p
Improved Glucose Control and Reduced Body Weight in Rodents with Dual Mechanism of Action Peptide Hybrids
<div><p>Combination therapy is being increasingly used as a treatment paradigm for metabolic diseases such as diabetes and obesity. In the peptide therapeutics realm, recent work has highlighted the therapeutic potential of chimeric peptides that act on two distinct receptors, thereby harnessing parallel complementary mechanisms to induce additive or synergistic benefit compared to monotherapy. Here, we extend this hypothesis by linking a known anti-diabetic peptide with an anti-obesity peptide into a novel peptide hybrid, which we termed a phybrid. We report on the synthesis and biological activity of two such phybrids (AC164204 and AC164209), comprised of a glucagon-like peptide-1 receptor (GLP1-R) agonist, and exenatide analog, AC3082, covalently linked to a second generation amylin analog, davalintide. Both molecules acted as full agonists at their cognate receptors <i>in vitro</i>, albeit with reduced potency at the calcitonin receptor indicating slightly perturbed amylin agonism. In obese diabetic <i>Lep<sup>ob</sup>/Lep</i><sup><i>ob</i></sup> mice sustained infusion of AC164204 and AC164209 reduced glucose and glycated haemoglobin (Hb<sub>A1c</sub>) equivalently but induced greater weight loss relative to exenatide administration alone. Weight loss was similar to that induced by combined administration of exenatide and davalintide. In diet-induced obese rats, both phybrids dose-dependently reduced food intake and body weight to a greater extent than exenatide or davalintide alone, and equal to co-infusion of exenatide and davalintide. Phybrid-mediated and exenatide + davalintide-mediated weight loss was associated with reduced adiposity and preservation of lean mass. These data are the first to provide <i>in vivo</i> proof-of-concept for multi-pathway targeting in metabolic disease via a peptide hybrid, demonstrating that this approach is as effective as co-administration of individual peptides.</p> </div
Flowchart of phybrid characterization of receptor activity and <i>in</i><i>vivo</i> efficacy.
<p>After synthesis, the ability of the GLP-1 and amylinomimetic portions of the phybrid to activate their appropriate receptors was assessed: activation of cAMP in cells expressing the GLP-1R or the CT receptor. Acute <i>in </i><i>vivo</i> characteristics of GLP-1 and amylin physiology were then assessed: glucose-lowering in mice for GLP-1 activity, insulin secretion in rats for GLP-1 activity and calcium-lowering in rats for amylin activity. In chronic efficacy models to more accurately gauge the ability of the phybrids to render equal or superior metabolic control relative to mono- or dual-therapy we utilized two models: obese, diabetic mice to assess impact on chronic glucose control, and DIO rats to assess impact on food intake, body weight and body composition.</p
Phybrid peptides induced greater weight loss compared to single peptide treatment and improved glycemic control similar to GLP-1 receptor agonism in obese diabetic <i>Lep<sup>ob</sup>/Lep</i><sup><i>ob</i></sup> mice.
<p>(<b>A</b>) Change in HbA1c, (<b>B</b>) change in plasma glucose, (<b>C</b>) total food intake, expressed as a percentage of vehicle, and (<b>D</b>) change in body weight following subcutaneous peptide infusion in leptin-deficient <i>Lep<sup>ob</sup>/Lep</i><sup><i>ob</i></sup> mice for 28 days. Groups not sharing the same superscript letter were significantly different from each other (p<0.05).</p