Lisa Porter

Exenatide once weekly versus twice daily for the treatment of type 2 diabetes: a randomised, open-label, non-inferiority study

BACKGROUND Exenatide is an incretin mimetic that shares glucoregulatory properties with glucagon-like peptide 1 (GLP-1), and improves glycaemic control, with progressive bodyweight reductions, when administered twice a day in patients with type 2 diabetes. We compared the efficacy of a once-weekly formulation of exenatide to that of a twice daily dose. METHODS A 30-week, randomised, non-inferiority study compared a long-acting release formulation of exenatide 2 mg administered once weekly to 10 mug exenatide administered twice a day, in 295 patients with type 2 diabetes (haemoglobin A(1c) [HbA(1c)] 8.3% [SD 1.0], mean fasting plasma glucose 9 [SD 2] mmol/L, weight 102 [SD 20] kg, diabetes duration 6.7 [SD 5.0] years). The patients were naive to drug therapy, or on one or more oral antidiabetic agents. The primary endpoint was the change in HbA(1c) at 30 weeks. This study is registered with ClinicalTrials.gov, number NCT00308139. FINDINGS At 30 weeks, the patients given exenatide once a week had significantly greater changes in HbA(1c) than those given exenatide twice a day (-1.9 [SE 0.1%] vs -1.5 [0.1%], 95% CI -0.54% to -0.12%; p=0.0023). A significantly greater proportion of patients receiving treatment once a week versus twice a day achieved target HbA(1c) levels of 7.0% or less (77%vs 61% of evaluable patients, p=0.0039). INTERPRETATION Exenatide once weekly resulted in significantly greater improvements in glycaemic control than exenatide given twice a day, with no increased risk of hypoglycaemia and similar reductions in bodyweight.

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.

Exenatide once weekly versus liraglutide once daily in patients with type 2 diabetes (DURATION-6): a randomised, open-label study

BACKGROUND Glucagon-like peptide-1 receptor agonists exenatide and liraglutide have been shown to improve glycaemic control and reduce bodyweight in patients with type 2 diabetes. We compared the efficacy and safety of exenatide once weekly with liraglutide once daily in patients with type 2 diabetes. METHODS We did a 26 week, open-label, randomised, parallel-group study at 105 sites in 19 countries between Jan 11, 2010, and Jan 17, 2011. Patients aged 18 years or older with type 2 diabetes treated with lifestyle modification and oral antihyperglycaemic drugs were randomly assigned (1:1), via a computer-generated randomisation sequence with a voice response system, to receive injections of once-daily liraglutide (1·8 mg) or once-weekly exenatide (2 mg). Participants and investigators were not masked to treatment assignment. The primary endpoint was change in glycated haemoglobin (HbA(1c)) from baseline to week 26. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01029886. FINDINGS Of 912 randomised patients, 911 were included in the intention-to-treat analysis (450 liraglutide, 461 exenatide). The least-squares mean change in HbA(1c) was greater in patients in the liraglutide group (-1·48%, SE 0·05; n=386) than in those in the exenatide group (-1·28%, 0·05; 390) with the treatment difference (0·21%, 95% CI 0·08-0·33) not meeting predefined non-inferiority criteria (upper limit of CI <0·25%). The most common adverse events were nausea (93 [21%] in the liraglutide group vs 43 [9%] in the exenatide group), diarrhoea (59 [13%] vs 28 [6%]), and vomiting 48 [11%] vs 17 [4%]), which occurred less frequently in the exenatide group and with decreasing incidence over time in both groups. 24 (5%) patients allocated to liraglutide and 12 (3%) allocated to exenatide discontinued participation because of adverse events. INTERPRETATION Both once daily liraglutide and once weekly exenatide led to improvements in glycaemic control, with greater reductions noted with liraglutide. These findings, plus differences in injection frequency and tolerability, could inform therapeutic decisions for treatment of patients with type 2 diabetes. FUNDING Eli Lilly and Company and Amylin Pharmaceuticals LLC.

DURATION-5: exenatide once weekly resulted in greater improvements in glycemic control compared with exenatide twice daily in patients with type 2 diabetes.

CONTEXT We wanted to understand the effects of once-weekly vs. twice-daily glucagon-like peptide-1 receptor agonism for treatment of patients with type 2 diabetes. OBJECTIVE The objective of the study was to compare effects of exenatide once weekly (ExQW) and exenatide twice daily (ExBID) on glycemic control, body weight, and safety. DESIGN This was a 24-wk, randomized, open-label, comparator-controlled study. SETTING The study was conducted at 43 sites in the United States. PATIENTS The study population was 252 intent-to-treat patients with type 2 diabetes [baseline (mean ± SD): glycosylated hemoglobin (HbA1c) 8.4 ± 1.2%, fasting plasma glucose 171 ± 47 mg/dl, weight 96 ± 20 kg] that were drug naïve (19%) or previously treated with one (47%) or multiple (35%) oral antidiabetic medications. INTERVENTIONS Interventions included ExQW 2 mg for 24 wk or ExBID 5 μg for 4 wk followed by ExBID 10 μg for 20 wk. MAIN OUTCOME MEASURE The change in HbA1c from baseline to wk 24 was measured. RESULTS At 24 wk, ExQW produced significantly greater changes from baseline (least squares mean ± SE) vs. ExBID in HbA1c (-1.6 ± 0.1% vs. -0.9 ± 0.1%; P < 0.0001) and fasting plasma glucose (-35 ± 5 mg/dl vs. -12 ± 5 mg/dl; P = 0.0008). Similar reductions in mean body weight from baseline to wk 24 were observed in both groups (-2.3 ± 0.4 kg and -1.4 ± 0.4 kg). Both treatments were generally well tolerated. Transient and predominantly mild to moderate nausea, the most frequent adverse event, was less common with ExQW (14%) than with ExBID (35%). Injection-site reactions were infrequent, but more common with ExQW. No major hypoglycemia occurred. CONCLUSIONS Continuous glucagon-like peptide-1 receptor agonism with ExQW resulted in superior glycemic control, with less nausea, compared with ExBID in patients with type 2 diabetes. Both groups lost weight.

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 ≤6.5%, respectively. In both treatment arms, FPG was reduced by >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 μg) 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) ≥70–<100 mg/dl. Pramlintide and an RAIA were initiated on day 1 and week 4, respectively. The proportion of patients achieving A1C ≤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.

Rationale and design of the EXenatide study of cardiovascular event lowering (EXSCEL) trial

Exenatide once-weekly is an extended release formulation of exenatide, a glucagon-like peptide-1 receptor agonist, which can improve glycemic control, body weight, blood pressure, and lipid levels in patients with type 2 diabetes mellitus (T2DM). The EXenatide Study of Cardiovascular Event Lowering (EXSCEL) will compare the impact of adding exenatide once-weekly to usual care with usual care alone on major cardiovascular outcomes. EXSCEL is an academically led, phase III/IV, double-blind, pragmatic placebo-controlled, global trial conducted in 35 countries aiming to enrol 14,000 patients with T2DM and a broad range of cardiovascular risk over approximately 5 years. Participants will be randomized (1:1) to receive exenatide once-weekly 2 mg or matching placebo by subcutaneous injections. The trial will continue until 1,360 confirmed primary composite cardiovascular end points, defined as cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke, have occurred. The primary efficacy hypothesis is that exenatide once-weekly is superior to usual care with respect to the primary composite cardiovascular end point. EXSCEL is powered to detect a 15% relative risk reduction in the exenatide once-weekly group, with 85% power and a 2-sided 5% alpha. The primary safety hypothesis is that exenatide once-weekly is noninferior to usual care with respect to the primary cardiovascular composite end point. Noninferiority will be concluded if the upper limit of the CI is <1.30. EXSCEL will assess whether exenatide once-weekly can reduce cardiovascular events in patients with T2DM with a broad range of cardiovascular risk. It will also provide long-term safety information on exenatide once-weekly in people with T2DM. ClinicalTrials.gov Identifier: NCT01144338.

Exenatide at therapeutic and supratherapeutic concentrations does not prolong the QTc interval in healthy subjects

Aims Exenatide has been demonstrated to improve glycaemic control in patients with type 2 diabetes, with no effect on heart rate corrected QT (QTc) at therapeutic concentrations. This randomized, placebo- and positive-controlled, crossover, thorough QT study evaluated the effects of therapeutic and supratherapeutic exenatide concentrations on QTc. Methods Intravenous infusion was employed to achieve steady-state supratherapeutic concentrations in healthy subjects within a reasonable duration (i.e. days). Subjects received exenatide, placebo and moxifloxacin, with ECGs recorded pre-therapy and during treatment. Intravenous exenatide was expected to increase heart rate to a greater extent than subcutaneous twice daily or once weekly formulations. To assure proper heart rate correction, a wide range of baseline heart rates was assessed and prospectively defined methodology was applied to determine the optimal QT correction. Results Targeted steady-state plasma exenatide concentrations were exceeded (geometric mean ± SEM 253 ± 8.5 pg ml−1, 399 ± 11.9 pg ml−1 and 627 ± 21.2 pg ml−1). QTcP, a population-based method, was identified as the most appropriate heart rate correction and was prespecified for primary analysis. The upper bound of the two-sided 90% confidence interval for placebo-corrected, baseline-adjusted QTcP (ΔΔQTcP) was <10 ms at all time points and exenatide concentrations. The mean of three measures assessed at the highest steady-state plasma exenatide concentration of ∼500 pg ml−1 (ΔΔQTcPavg) was −1.13 [−2.11, −0.15). No correlation was observed between ΔΔQTcP and exenatide concentration. Assay sensitivity was confirmed with moxifloxacin. Conclusions These results demonstrated that exenatide, at supratherapeutic concentrations, does not prolong QTc and provide an example of methodology for QT assessment of drugs with an inherent heart rate effect.

Exenatide once weekly: sustained improvement in glycemic control and cardiometabolic measures through 3 years

Background Type 2 diabetes mellitus is a progressive metabolic disease necessitating therapies with sustained efficacy and safety over time. Exenatide once weekly (ExQW), an extended-release formulation of the glucagon-like peptide-1 receptor agonist exenatide, has demonstrated improvements in glycemic and cardiometabolic measures from 30 weeks to 2 years of treatment. Here, the efficacy and safety of treatment with ExQW for 3 years are described. Methods Patients were initially randomized to receive either ExQW (2 mg) or exenatide twice daily for 30 weeks. Following the initial 30 weeks, all patients were treated with ExQW in an open-label extension. Analyses of primary glycemic endpoints, beta-cell function, and cardiometabolic measures were assessed for patients who completed 3 years of ExQW treatment and for the intention-to-treat population. Safety and tolerability analyses were provided for the intention-to-treat population. Results Sixty-six percent of the intention-to-treat population (n = 295) completed 3 years of treatment (n = 194). At 3 years, a significant reduction in hemoglobin A1c (least squares mean ± standard error) of −1.6% ± 0.08% was observed, with 55% and 33% of patients achieving hemoglobin A1c targets of <7% and ≤6.5%, respectively. Consistent with a sustained reduction in hemoglobin A1c, improvements in beta-cell function were also observed. Body weight was significantly reduced by −2.3 ± 0.6 kg. Reductions in blood pressure, total cholesterol, low-density lipoprotein cholesterol, and triglycerides were also observed. Adverse events reported most frequently during both controlled and uncontrolled periods included diarrhea, nausea, and vomiting of mostly mild intensity. The incidence of these adverse events decreased over time. Incidence of minor hypoglycemia was low and no major hypoglycemia was observed. Conclusion ExQW produced clinically meaningful improvements in glycemic control that were durable through 3 years of treatment. Significant improvements in cardiometabolic measurements were also observed. ExQW was well-tolerated during long-term treatment and no new adverse events were noted. Trial registration ClinicalTrials.gov NCT00308139.

Pramlintide lowered glucose excursions and was well-tolerated in adolescents with type 1 diabetes: results from a randomized, single-blind, placebo-controlled, crossover study.

OBJECTIVES To evaluate the pharmacokinetics, pharmacodynamics, safety, and tolerability of pramlintide in treating adolescents with type 1 diabetes. STUDY DESIGN Twelve subjects (9 females, 3 males, age 12 to 17 years; A1C, 8.4%; body mass index, 25 kg/m(2)) were randomized to pramlintide (15 or 30 microg) or placebo administered before a standardized breakfast. Insulin lispro (50% of usual mealtime dose) was injected separately. Acetaminophen (1000 mg) was administered orally to provide an indicator of gastric emptying rate. RESULTS In 9 evaluable subjects, plasma pramlintide concentrations increased dose-proportionately; mean peak plasma concentration (C(max)) (15-microg dose, 93 +/- 9 pg/mL; 30-microg dose, 202 +/- 21 pg/mL) occurred approximately 0.3 h (median time to peak concentration) after administration. Pramlintide reduced incremental area under the concentration curve (AUC(0-3h)) for glucagon and glucose versus placebo (glucagon: 15-microg dose, 4 +/- 7 pg(*)h/mL; 30-microg dose, 5 +/- 7 pg(*)h/mL; placebo, 35 +/- 9 pg(*)h/mL; glucose: 15-microg dose, 129 +/- 43 mg(*)h/dL; 30-microg dose, 132 +/- 37 mg(*)h/dL; placebo, 217 +/- 56 mg(*)h/dL). Acetaminophen C(max) decreased with pramlintide; median T(max) was delayed by approximately 2.6- to 3.8-fold. Pramlintide was well tolerated, and no treatment-related adverse events occurred. CONCLUSIONS Pramlintide reduced postprandial glucagon and glucose excursions and slowed gastric emptying in adolescents with type 1 diabetes, with no treatment-related adverse events. Long-term studies evaluating the efficacy and safety of pramlintide in adolescents are warranted.