Efficacy and safety of exenatide once weekly versus sitagliptin or pioglitazone as an adjunct to metformin for treatment of type 2 diabetes (DURATION-2): a randomised trial.

BACKGROUND: Most patients with type 2 diabetes begin pharmacotherapy with metformin, but eventually need additional treatment. We assessed the safety and efficacy of once weekly exenatide, a glucagon-like peptide 1 receptor agonist, versus maximum approved doses of the dipeptidyl peptidase-4 inhibitor, sitagliptin, or the thiazolidinedione, pioglitazone, in patients treated with metformin. METHODS: In this 26-week randomised, double-blind, double-dummy, superiority trial, patients with type 2 diabetes who had been treated with metformin, and at baseline had mean glycosylated haemoglobin (HbA(1c)) of 8.5% (SD 1.1), fasting plasma glucose of 9.1 mmol/L (2.6), and weight of 88.0 kg (20.1), were enrolled and treated at 72 sites in the USA, India, and Mexico. Patients were randomly assigned to receive: 2 mg injected exenatide once weekly plus oral placebo once daily; 100 mg oral sitagliptin once daily plus injected placebo once weekly; or 45 mg oral pioglitazone once daily plus injected placebo once weekly. Primary endpoint was change in HbA(1c) between baseline and week 26. Analysis was by intention to treat, for all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, number NCT00637273. FINDINGS: 170 patients were assigned to receive once weekly exenatide, 172 to receive sitagliptin, and 172 to receive pioglitazone. 491 patients received at least one dose of study drug and were included in the intention-to-treat analysis (160 on exenatide, 166 on sitagliptin, and 165 on pioglitazone). Treatment with exenatide reduced HbA(1c) (least square mean -1.5%, 95% CI -1.7 to -1.4) significantly more than did sitagliptin (-0.9%, -1.1 to -0.7) or pioglitazone (-1.2%, -1.4 to -1.0). Treatment differences were -0.6% (95% CI -0.9 to -0.4, p<0.0001) for exenatide versus sitagliptin, and -0.3% (-0.6 to -0.1, p=0.0165) for exenatide versus pioglitazone. Weight loss with exenatide (-2.3 kg, 95% CI-2.9 to -1.7) was significantly greater than with sitagliptin (difference -1.5 kg, 95% CI -2.4 to -0.7, p=0.0002) or pioglitazone (difference -5.1 kg, -5.9 to -4.3, p<0.0001). No episodes of major hypoglycaemia occurred. The most frequent adverse events with exenatide and sitagliptin were nausea (n=38, 24%, and n=16, 10%, respectively) and diarrhoea (n=29, 18%, and n=16, 10%, respectively); upper-respiratory-tract infection (n=17, 10%) and peripheral oedema (n=13, 8%) were the most frequent events with pioglitazone. INTERPRETATION: The goal of many clinicians who manage diabetes is to achieve optimum glucose control alongside weight loss and a minimum number of hypoglycaemic episodes. Addition of exenatide once weekly to metformin achieved this goal more often than did addition of maximum daily doses of either sitagliptin or pioglitazone. FUNDING: Amylin Pharmaceuticals and Eli Lilly.

DURATION-1: exenatide once weekly produces sustained glycemic control and weight loss over 52 weeks.

OBJECTIVE: In the Diabetes Therapy Utilization: Researching Changes in A1C, Weight and Other Factors Through Intervention with Exenatide Once Weekly (DURATION-1) study, the safety and efficacy of 30 weeks of treatment with the glucagon-like peptide-1 receptor agonist exenatide once weekly (exenatide QW; 2 mg) was compared with exenatide BID in 295 patients with type 2 diabetes. We now report the safety and efficacy of exenatide QW in 1) patients who continued treatment for an additional 22 weeks (52 weeks total) and 2) patients who switched from exenatide BID to exenatide QW after 30 weeks. RESEARCH DESIGN AND METHODS: In this randomized, multicenter, comparator-controlled, open-label trial, 258 patients entered the 22-week open-ended assessment phase (n = 128 QW-only; n = 130 BID-->QW). A1C, fasting plasma glucose (FPG), body weight, blood pressure, fasting lipids, safety, and tolerability were assessed. RESULTS: Patients continuing exenatide QW maintained A1C improvements through 52 weeks (least squares mean -2.0% [95% CI -2.1 to -1.8%]). Patients switching from exenatide BID to exenatide QW achieved further A1C improvements; both groups exhibited the same A1C reduction and mean A1C (6.6%) at week 52. At week 52, 71 and 54% of all patients achieved A1C <7.0% and 40 mg/dl, and body weight was reduced by >4 kg after 52 weeks. Nausea occurred less frequently in this assessment period and was predominantly mild. No major hypoglycemia was observed. CONCLUSION: Exenatide QW elicited sustained improvements in glycemic control and body weight through 52 weeks of treatment. Patients switching to exenatide QW experienced further improvements in A1C and FPG, with sustained weight loss.

Randomized comparison of pramlintide or mealtime insulin added to basal insulin treatment for patients with type 2 diabetes.

OBJECTIVE: To compare the efficacy and safety of adding mealtime pramlintide or rapid-acting insulin analogs (RAIAs) to basal insulin for patients with inadequately controlled type 2 diabetes. RESEARCH DESIGN AND METHODS: In a 24-week open-label, multicenter study, 113 patients were randomly assigned 1:1 to addition of mealtime pramlintide (120 microg) or a titrated RAIA to basal insulin and prior oral antihyperglycemic drugs (OADs). At screening, patients were insulin naive or had been receiving <50 units/day basal insulin for <6 months. The basal insulin dosage was titrated from day 1, seeking fasting plasma glucose (FPG) > or =70-<100 mg/dl. Pramlintide and an RAIA were initiated on day 1 and week 4, respectively. The proportion of patients achieving A1C < or =7.0% without weight gain or severe hypoglycemia at week 24 was the primary end point. RESULTS: More pramlintide- than RAIA-treated patients achieved the primary end point (30 vs. 11%, P = 0.018) with a similar dose of basal insulin. Pramlintide and an RAIA yielded similar mean +/- SEM values for FPG and A1C at 24 weeks (122 +/- 7 vs. 123 +/- 5 mg/dl and 7.2 +/- 0.2 vs. 7.0 +/- 0.1%, respectively) and similar least squares mean reductions from baseline to end point (-31 +/- 6 vs. -34 +/- 6 mg/dl and -1.1 +/- 0.2 vs. -1.3 +/- 0.2%, respectively). RAIAs but not pramlintide caused weight gain (+4.7 +/- 0.7 vs. +0.0 +/- 0.7 kg, P < 0.0001). Fewer patients reported mild to moderate hypoglycemia with pramlintide than with the RAIA (55 vs. 82%), but more patients reported nausea (21 vs. 0%). No severe hypoglycemia occurred in either group. CONCLUSIONS: In patients taking basal insulin and OADs, premeal fixed-dose pramlintide improved glycemic control as effectively as titrated RAIAs. The pramlintide regimen sometimes caused nausea but no weight gain and less hypoglycemia.

Exenatide once weekly for the treatment of type 2 diabetes.

Exenatide is the first glucagon-like peptide-1 (GLP-1) receptor agonist approved for the treatment of type 2 diabetes mellitus (T2DM). Exenatide lowers blood glucose through multiple mechanisms, including enhancement of glucose-dependent insulin secretion, suppression of excess glucagon secretion, reduction of food intake and slowing of gastric emptying. The current formulation of exenatide requires twice-daily dosing (exenatide BID), and an extended-release formulation of exenatide is now in development for use as a once-weekly injection (exenatide QW). The purpose of this report is to review the most current clinical data on the development of exenatide QW for the treatment of T2DM. In clinical trials, exenatide QW significantly improved glycemic control, resulted in patient weight loss, and was well tolerated in patients with T2DM. In a head-to-head clinical trial, exenatide QW caused greater improvements in glycemic control and was better tolerated than exenatide BID. Given the rapidly increasing prevalence of diabetes and obesity worldwide, exenatide QW is a promising development candidate for the treatment of T2DM.

Pramlintide in the treatment of diabetes mellitus.

Pramlintide, the first member of a new class of drugs for the treatment of insulin-using patients with type 2 or type 1 diabetes mellitus, is an analog of the peptide hormone amylin. Amylin is co-secreted with insulin from pancreatic beta cells and acts centrally to slow gastric emptying, suppress postprandial glucagon secretion, and decrease food intake. These actions complement those of insulin to regulate blood glucose concentrations. Amylin is relatively deficient in patients with type 2 diabetes, depending on the severity of beta-cell secretory failure, and is essentially absent in patients with type 1 diabetes. Through mechanisms similar to those of amylin, pramlintide improves overall glycemic control, reduces postprandial glucose levels, and reduces bodyweight in patients with diabetes using mealtime insulin. Reductions in postprandial glucose and bodyweight are important, since postprandial hyperglycemia is associated with an increased risk of microvascular and macrovascular complications, and increased weight is an independent risk factor for cardiovascular disease. Pramlintide is generally well tolerated, with the most frequent treatment-emergent adverse event being mild to moderate nausea, which decreases over time. Pramlintide treatment is also associated with improvements in markers of oxidative stress and cardiovascular risk and improved patient-reported treatment satisfaction. These factors make pramlintide an attractive option for the treatment of postprandial hyperglycemia in patients with diabetes using mealtime insulin.

Effect of pramlintide as an adjunct to basal insulin on markers of cardiovascular risk in patients with type 2 diabetes.

OBJECTIVE: Intensification of insulin therapy in patients with type 2 diabetes, while improving glycemic control, often leads to an increase in body weight and other markers of cardiovascular risk. The effects of pramlintide as an adjunct to basal insulin titration (without mealtime insulin) on glycemia and cardiovascular risk markers were examined. RESEARCH DESIGN AND METHODS: This was a post hoc analysis of a 16-week, double-blind, placebo-controlled study in patients with type 2 diabetes (N = 211) using insulin glargine (without mealtime insulin) +/- oral agents. Patients were randomized to treatment with placebo or pramlintide (60 or 120 mug with major meals), and insulin glargine was titrated to target a fasting plasma glucose concentration of > or = 70 to < 100 mg/dL. MAIN OUTCOME MEASURES: Endpoints included the change from baseline to Week 16 in body weight, high sensitivity C-reactive protein (hsCRP), triglycerides, HDL, LDL, and blood pressure. RESULTS: Pramlintide-treated patients lost weight and placebo-treated patients gained weight during 16 weeks of treatment (-1.6 +/- 0.3 kg vs. +0.7 +/- 0.3 kg, p < 0.001; mean +/- SE). hsCRP was reduced in pramlintide-treated versus placebo-treated patients (-0.8 +/- 0.2 mg/L vs. 0.1 +/- 0.2 mg/L, p < 0.01; mean +/- SE). Patients with baseline hsCRP > 3 mg/L (high cardiovascular risk) demonstrated greater hsCRP reductions with pramlintide versus placebo treatment at Week 16 (p < 0.05). Patients with baseline triglycerides > or = 150 mg/dL or > or = 200 mg/dL (high cardiovascular risk) showed significant reductions from baseline in triglyceride concentrations with pramlintide (-43 +/- 14 mg/dL or -59 +/- 19 mg/dL; p < 0.05; mean +/- SE) but not with placebo (1 +/- 29 mg/dL or -3 +/- 54 mg/dL; mean +/- SE). No significant differences between pramlintide and placebo were observed for changes in HDL, LDL, or blood pressure. Pramlintide treatment was generally well tolerated. The most frequent adverse event related to pramlintide was mild-to-moderate nausea (31% pramlintide vs. 10% placebo). Pramlintide added to basal insulin did not increase the incidence of hypoglycemia. A limitation of the study was its relatively short duration. CONCLUSIONS: Pramlintide, as an adjunct to basal insulin, was associated with improvements in several cardiovascular risk markers, warranting long-term clinical studies to determine its potential effects on cardiovascular risk.