Engineering and characterization of the long-acting glucagon-like peptide-1 analogue LY2189265, an Fc fusion protein

BACKGROUND

Glucagon-like peptide-1 (GLP-1) receptor agonists are novel agents for type 2 diabetes treatment, offering glucose-dependent insulinotropic effects, reduced glucagonemia and a neutral bodyweight or weight-reducing profile. However, a short half-life (minutes), secondary to rapid inactivation by dipeptidyl peptidase-IV (DPP-IV) and excretion, limits the therapeutic potential of the native GLP-1 hormone. Recently, the GLP-1 receptor agonist exenatide injected subcutaneously twice daily established a novel therapy class. Developing long-acting and efficacious GLP-1 analogues represents a pivotal research goal. We developed a GLP-1 immunoglobulin G (IgG4) Fc fusion protein (LY2189265) with extended pharmacokinetics and activity.

METHODS

In vitro and in vivo activity of LY2189265 was characterized in rodent and primate cell systems and animal models.

RESULTS

LY2189265 retained full receptor activity in vitro and elicited insulinotropic activity in islets similar to native peptide. Half-life in rats and cynomolgus monkeys was 1.5-2 days, and serum immunoreactivity representing active compound persisted > 6 days. In rats, LY2189265 enhanced insulin responses during graded glucose infusion 24 h after one dose. LY2189265 increased glucose tolerance in diabetic mice after one dose and lowered weight and delayed hyperglycaemia when administered twice weekly for 4 weeks. In monkeys, LY2189265 significantly increased glucose-dependent insulin secretion for up to a week after one dose, retained efficacy when administered subchronically (once weekly for 4 weeks) and was well tolerated.

CONCLUSIONS

LY2189265 retains the effects of GLP-1 with increased half-life and efficacy, supporting further evaluation as a once-weekly treatment of type 2 diabetes.

Hepatic and glucagon-like peptide-1-mediated reversal of diabetes by glucagon receptor antisense oligonucleotide inhibitors

Uncontrolled hepatic glucose production contributes significantly to hyperglycemia in patients with type 2 diabetes. Hyperglucagonemia is implicated in the etiology of this condition; however, effective therapies to block glucagon signaling and thereby regulate glucose metabolism do not exist. To determine the extent to which blocking glucagon action would reverse hyperglycemia, we targeted the glucagon receptor (GCGR) in rodent models of type 2 diabetes using 2'-methoxyethyl-modified phosphorothioate-antisense oligonucleotide (ASO) inhibitors. Treatment with GCGR ASOs decreased GCGR expression, normalized blood glucose, improved glucose tolerance, and preserved insulin secretion. Importantly, in addition to decreasing expression of cAMP-regulated genes in liver and preventing glucagon-mediated hepatic glucose production, GCGR inhibition increased serum concentrations of active glucagon-like peptide-1 (GLP-1) and insulin levels in pancreatic islets. Together, these studies identify a novel mechanism whereby GCGR inhibitors reverse the diabetes phenotype by the dual action of decreasing hepatic glucose production and improving pancreatic beta cell function.

Effects on weight loss and glycemic control with SAR441255, a potent unimolecular peptide GLP-1/GIP/GCG receptor triagonist

Unimolecular triple incretins, combining the activity of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon (GCG), have demonstrated reduction in body weight and improved glucose control in rodent models. We developed SAR441255, a synthetic peptide agonist of the GLP-1, GCG, and GIP receptors, structurally based on the exendin-4 sequence. SAR441255 displays high potency with balanced activation of all three target receptors. In animal models, metabolic outcomes were superior to results with a dual GLP-1/GCG receptor agonist. Preclinical in vivo positron emission tomography imaging demonstrated SAR441255 binding to GLP-1 and GCG receptors. In healthy subjects, SAR441255 improved glycemic control during a mixed-meal tolerance test and impacted biomarkers for GCG and GIP receptor activation. Single doses of SAR441255 were well tolerated. The results demonstrate that integrating GIP activity into dual GLP-1 and GCG receptor agonism provides improved effects on weight loss and glycemic control while buffering the diabetogenic risk of chronic GCG receptor agonism.

Basal insulin peglispro demonstrates preferential hepatic versus peripheral action relative to insulin glargine in healthy subjects

OBJECTIVE

We evaluated the endogenous glucose production (EGP) and glucose disposal rate (GDR) over a range of doses of basal insulin peglispro (BIL) and insulin glargine in healthy subjects.

RESEARCH DESIGN AND METHODS

This was a single-center, randomized, open-label, four-period, incomplete-block, crossover study conducted in eight healthy male subjects. Subjects had 8-h euglycemic clamps performed with primed, continuous infusions of BIL (5.1 to 74.1 mU/min) in three dosing periods and insulin glargine (20 or 30 mU/m(2)/min) in a fourth period, targeted to achieve 50-100% suppression of EGP. D-[3-(3)H] glucose was infused to assess rates of glucose appearance and disappearance.

RESULTS

Mean BIL and insulin glargine concentrations (targeted to reflect the differences in intrinsic affinities of the two basal insulins) ranged from 824 to 11,400 and 212 to 290 pmol/L, respectively, and increased accordingly with increases in dose. Suppression of EGP and stimulation of GDR were observed with increasing concentrations of both insulins. At insulin concentrations where EGP was significantly suppressed, insulin glargine resulted in increased GDR. In contrast, at comparable suppression of EGP, BIL had minimal effect on GDR at lower doses and had substantially less effect on GDR than insulin glargine at higher doses.

CONCLUSIONS

The novel basal insulin analog BIL has relative hepatopreferential action and decreased peripheral action, compared with insulin glargine, in healthy subjects.

Evaluation of a mathematical model of diabetes progression against observations in the Diabetes Prevention Program

The seminal publication of the Diabetes Prevention Program (DPP) results in 2002 has provided insight into the impact of major therapies on the development of diabetes over a time span of a few years. In the present work, the publicly available DPP data set is used to calibrate and evaluate a recently developed mechanistic mathematical model for the long-term development of diabetes to assess the model's ability to predict the natural history of disease progression and the effectiveness of preventive interventions. A general population is generated from which virtual subject samples corresponding to the DPP enrollment criteria are selected. The model is able to reproduce with good fidelity the observed time courses of both diabetes incidence and average glycemia, under realistic hypotheses on evolution of disease and efficacy of the studied therapies, for all treatment arms. Model-based simulations of the long-term evolution of the disease are consistent with the transient benefits observed with conventional therapies and with promising effects of radical improvement of insulin sensitivity (as by metabolic surgery) or of β-cell protection. The mechanistic diabetes progression model provides a credible tool by which long-term implications of antidiabetic interventions can be evaluated.

Reduced peripheral activity leading to hepato-preferential action of basal insulin peglispro compared with insulin glargine in patients with type 1 diabetes

AIMS

Basal insulin peglispro (BIL), a novel PEGylated basal insulin with a large hydrodynamic size, has a delayed absorption and reduced clearance that prolongs the duration of action. The current study compared the effects of BIL and insulin glargine (GL) on endogenous glucose production (EGP), glucose disposal rate (GDR) and lipolysis in patients with type 1 diabetes.

MATERIALS AND METHODS

This was a randomized, open-label, four-period, crossover study. Patients received intravenous infusions of BIL and GL, each at two dose levels selected for partial and maximal suppression of EGP, during an 8 to 10 h euglycemic clamp procedure with d-[3-³ H] glucose.

RESULTS

Following correction for equivalent human insulin concentrations (EHIC), low-dose GL infusion resulted in similar EGP at the end of the clamp compared to low-dose BIL infusion (GL/BIL ratio of 1.03) but a higher GDR (GL/BIL ratio of 2.42), indicating similar hepatic activity but attenuated peripheral activity of BIL. Consistent with this, the EHIC-corrected GDR/EGP at the end of the clamp was 1.72-fold greater for GL than BIL following low-dose administration. At the lower dose of BIL and GL (concentrations in the therapeutic range), BIL produced less suppression of lipolysis compared with GL as indicated by free fatty acid and glycerol levels at the end of the clamp.

CONCLUSIONS

Compared with GL, BIL restored the hepato-peripheral insulin action gradient seen in normal physiology via its peripherally restricted action on target tissues related to carbohydrate and lipid metabolism.

Attenuated suppression of lipolysis explains the increases in triglyceride secretion and concentration associated with basal insulin peglispro relative to insulin glargine treatment in patients with type 1 diabetes

AIMS

To test the hypothesis that, as well as lowering weight and increasing plasma triglyceride (TG) levels and hepatic fat compared with insulin glargine (GL) in patients with type 1 diabetes, the attenuated peripheral effects of basal insulin peglispro (BIL) may include increased free fatty acid flux to the liver, causing increased very-low-density lipoprotein (VLDL)-TG secretion and lipid oxidation, and decreased TG adipose tissue deposition.

METHODS

In this open-label, randomized, 2-period crossover study, 14 patients with type 1 diabetes received once-daily, individualized, stable BIL or GL doses for 3 weeks. Palmitate flux was assessed using [9,10-3 H]palmitate infusion. VLDL-TG secretion, clearance and oxidation rate were assessed using primed-constant infusion of ex vivo labelled [1-14 C]VLDL-TG, while VLDL-TG storage rate was assessed using [9,10-3 H]VLDL-TG bolus injection.

RESULTS

The VLDL-TG concentration and secretion rate, and palmitate flux were statistically significantly higher during BIL than during GL treatment (58%, 51% and 35%, respectively). The ratios of least squares (LS) geometric means for VLDL-TG clearance and oxidation were 0.92 (95% confidence interval [CI] 0.72, 1.17) and 1.31 (95% CI 0.91, 1.90), respectively. The difference in LS means for VLDL-TG storage rate was -0.36 (95% CI -0.83, 0.12).

CONCLUSIONS

BIL-treated patients had higher effective lipolysis, VLDL-TG secretion and VLDL-TG concentration compared with GL-treated patients, explaining the increased plasma TG concentrations reported previously. Data support attenuated effects of BIL on lipolysis, in addition to the recently described hepato-preferential glucodynamic effects.

Quantification of Basal Insulin Peglispro and Human Insulin in Adipose Tissue Interstitial Fluid by Open-Flow Microperfusion

BACKGROUND

Restoration of the physiologic hepatic-to-peripheral insulin gradient may be achieved by either portal vein administration or altering insulin structure to increase hepatic specificity or restrict peripheral access. Basal insulin peglispro (BIL) is a novel, PEGylated basal insulin with a flat pharmacokinetic and glucodynamic profile and altered hepatic-to-peripheral action gradient. We hypothesized reduced BIL exposure in peripheral tissues explains the latter, and in this study assessed the adipose tissue interstitial fluid (ISF) concentrations of BIL compared with human insulin (HI).

METHODS

A euglycemic glucose clamp was performed in patients with type 1 diabetes during continuous intravenous (IV) infusion of BIL or HI, while the adipose ISF insulin concentrations were determined using open-flow microperfusion (OFM). The ratio of adipose ISF-to-serum concentrations and the absolute steady-state adipose ISF concentrations were assessed using a dynamic no-net-flux technique with subsequent regression analysis.

RESULTS

Steady-state BIL concentrations in adipose tissue ISF were achieved by ∼16 h after IV infusion. Median time to reach steady-state glucose infusion rate across doses ranged between 8 and 22 h. The average serum concentrations (coefficient of variation %) of BIL and HI were 11,200 pmol/L (23%) and 425 pmol/L (15%), respectively. The ISF-to-serum concentration ratios were 10.2% for BIL and 22.9% for HI.

CONCLUSIONS

This study indicates feasibility of OFM to measure BIL in ISF. The observed low ISF-to-serum concentration ratio of BIL is consistent with its previously demonstrated reduced peripheral action.

Basal insulin peglispro increases lipid oxidation, metabolic flexibility, thermogenesis and ketone bodies compared to insulin glargine in subjects with type 1 diabetes mellitus

AIMS

When treated with basal insulin peglispro (BIL), patients with type 1 diabetes mellitus (T1DM) exhibit weight loss and lower prandial insulin requirements versus insulin glargine (GL), while total insulin requirements remain similar. One possible explanation is enhanced lipid oxidation and improved ability to switch between glucose and lipid metabolism with BIL. This study compared the effects of BIL and GL on glucose and lipid metabolism in subjects with T1DM.

MATERIALS AND METHODS

Fifteen subjects with T1DM were enrolled into this open-label, randomised, crossover study, and received once-daily stable, individualised, subcutaneous doses of BIL and GL for 4 weeks each. Respiratory quotient (RQ) was measured using whole-room calorimetry, and energy expenditure (EE) and concentrations of ketone bodies (3-hydroxybutyrate) and acylcarnitines were assessed.

RESULTS

Mean sleep RQ was lower during the BIL (0.822) than the GL (0.846) treatment period, indicating greater lipid metabolism during the post-absorptive period with BIL. Increases in carbohydrate oxidation following breakfast were greater during BIL than GL treatment (mean change in RQ following breakfast 0.111 for BIL, 0.063 for GL). Furthermore, BIL treatment increased total daily EE versus GL (2215.9 kcal/d for BIL, 2135.5 kcal/d for GL). Concentrations of ketone bodies and acylcarnitines appeared to be higher following BIL than GL treatment.

CONCLUSIONS

BIL increased sleeping fat oxidation, EE, ketone bodies, acylcarnitines and post-prandial glucose metabolism when switching from conventional insulin, thus, restoring metabolic flexibility and increasing thermogenesis. These changes may explain the previously observed weight loss with BIL versus GL.

Hypoglycemia Risk Related to Double Dose Is Markedly Reduced with Basal Insulin Peglispro Versus Insulin Glargine in Patients with Type 2 Diabetes Mellitus in a Randomized Trial: IMAGINE 8

BACKGROUND

Basal insulin peglispro (BIL) has a peripheral-to-hepatic distribution of action that resembles endogenous insulin and a prolonged duration of action with a flat pharmacokinetic/pharmacodynamic profile at steady state, characteristics that tend to reduce hypoglycemia risk compared to insulin glargine (GL). The primary objective was to demonstrate that clinically significant hypoglycemia (blood glucose ≤54 mg/dL [3.0 mmol/L] or symptoms of severe hypoglycemia) occurred less frequently within 84 h after a double dose (DD) of BIL than a DD of GL.

METHODS

This was a randomized, double-blind, two-period crossover study in patients with type 2 diabetes (T2D) previously treated with insulin (N = 68). For the first 3 weeks of each of the two crossover periods, patients received an individualized dose of BIL or GL once nightly (stable dose for 2 weeks/period). Then, during a 7-day inpatient stay with frequent blood glucose monitoring and standardized meals, one DD of study insulin was given. Glucose was infused if blood glucose was ≤54 mg/dL (3.0 mmol/L) or for symptoms of severe hypoglycemia.

RESULTS

Within 84 h after the DD, a significantly smaller proportion of patients experienced clinically significant hypoglycemia with BIL compared to GL (BIL, 6.6%; GL, 35.5%; odds ratio for BIL/GL 0.13 [95% confidence interval 0.04-0.39]; P < 0.001). Adverse event profiles were similar for the two insulins. Serum alanine aminotransferase and triglyceride levels were significantly higher with BIL versus GL.

CONCLUSIONS

BIL has a markedly lower risk of hypoglycemia than GL when replicating a double-dose error in patients with T2D.

Novel hepato-preferential basal insulin peglispro (BIL) does not differentially affect insulin sensitivity compared with insulin glargine in patients with type 1 and type 2 diabetes

AIMS

Basal insulin peglispro (BIL) is a novel PEGylated basal insulin with a flat pharmacokinetic and glucodynamic profile and reduced peripheral effects, which results in a hepato-preferential action. In Phase 3 trials, patients with T1DM treated with BIL had lower prandial insulin requirements, yet improved prandial glucose control, relative to insulin glargine (GL). We hypothesized that this may be because of an enhanced sensitivity to prandial insulin with BIL resulting from lower chronic peripheral insulin action.

MATERIALS AND METHODS

Two open-label, randomized, 2-period crossover clinical studies were conducted in 28 patients with T1DM and 24 patients with T2DM. In each study period, patients received once-daily, individualized, stable, subcutaneous doses of BIL or GL for 5 weeks before a euglycaemic 2-step hyperinsulinemic clamp procedure (with [6,6- ² H₂ ]-glucose in 12 of the patients with T1DM). M-values were derived from the clamp procedure for all patients, with rate of glucose appearance (Ra) and disappearance (Rd) and insulin sensitivity index (SI) determined from the clamps with [6,6- ² H₂ ]-glucose.

RESULTS

There were no statistically significant differences between BIL and GL in key measures of hepatic (% Ra suppression during the low-dose insulin infusion; 78.7% with BIL, 81.8% with GL) or peripheral (M-value and M/I during the high-dose insulin infusion, Rd and SI) insulin sensitivity in patients with T1DM or T2DM.

CONCLUSIONS

The need to reduce prandial insulin observed with BIL during phase 3 trials cannot be explained by the differential effects of BIL and GL on sensitivity to prandial insulin in either T1DM or T2DM.