Safety and tolerability of exenatide once weekly in patients with type 2 diabetes: an integrated analysis of 4,328 patients

Appendicitis: A Hidden Danger of GLP-1 Receptor Agonists?

Introduction: While glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have become increasingly prescribed, use is often inhibited by the gastrointestinal adverse effects that patients must endure. Nausea, vomiting, and cholelithiasis are most commonly associated with use, with little to no data or labeling reflecting risk of appendicitis or associated symptoms. Appendicitis etiology is theorized to develop secondary to obstruction of the vermiform via infection or fecalith causing an increase in intraluminal pressure. It is hypothesized that given the aforementioned gastrointestinal effects associated with GLP-1 RAs, patients taking such agents may be more at risk for developing this acute condition. Patient Case: We describe a case of a 48-year-old woman who presented to the emergency department several months after being initiated on Ozempic (semaglutide). This report aims to analyze the potential secondary adverse effects that may result from GLP-1 RA use. Her examination was positive for focal abdominal tenderness and leukocytosis along with imaging suggestive of appendicitis. Her acute condition ultimately required an appendectomy. Discussion: While minimal data are available to suggest significant causation between GLP-1 RAs and appendicitis, a literature and database search revealed that instances may be more common than previously thought. Conclusion: Trial results and adverse event reporting systems report an infrequent incidence in patients using these medications, but this report aims to contribute to the literature describing this potential adverse event.

The effect of GLP-1RA exenatide on idiopathic intracranial hypertension: a randomized clinical trial

Therapeutics to reduce intracranial pressure are an unmet need. Preclinical data have demonstrated a novel strategy to lower intracranial pressure using glucagon-like peptide-1 (GLP-1) receptor signalling. Here, we translate these findings into patients by conducting a randomized, placebo-controlled, double-blind trial to assess the effect of exenatide, a GLP-1 receptor agonist, on intracranial pressure in idiopathic intracranial hypertension. Telemetric intracranial pressure catheters enabled long-term intracranial pressure monitoring. The trial enrolled adult women with active idiopathic intracranial hypertension (intracranial pressure >25 cmCSF and papilloedema) who receive subcutaneous exenatide or placebo. The three primary outcome measures were intracranial pressure at 2.5 h, 24 h and 12 weeks and alpha set a priori at less than 0.1. Among the 16 women recruited, 15 completed the study (mean age 28 ± 9, body mass index 38.1 ± 6.2 kg/m2, intracranial pressure 30.6 ± 5.1 cmCSF). Exenatide significantly and meaningfully lowered intracranial pressure at 2.5 h -5.7 ± 2.9 cmCSF (P = 0.048); 24 h -6.4 ± 2.9 cmCSF (P = 0.030); and 12 weeks -5.6 ± 3.0 cmCSF (P = 0.058). No serious safety signals were noted. These data provide confidence to proceed to a phase 3 trial in idiopathic intracranial hypertension and highlight the potential to utilize GLP-1 receptor agonist in other conditions characterized by raised intracranial pressure.

Exenatide Once Weekly for Management of Type 2 Diabetes: A Review

Exenatide is one of the exendin-based glucagon-like peptide 1 receptor agonists (GLP-1RAs) and is currently available in two formulations, ie, exenatide twice daily (BID), a short-acting GLP-1RA, and exenatide once weekly (QW), a long-acting GLP-1RA. Clinical efficacy and safety of exenatide 2 mg QW in patients with type 2 diabetes (T2DM) has been demonstrated in the DURATION study program. Exenatide QW has been shown to achieve greater HbA1c reduction compared with exenatide BID, with less injection frequency and greater treatment satisfaction. However, exenatide QW failed to show a significant cardiovascular risk reduction in a cardiovascular outcome trial (CVOT), the EXSCEL trial, while other GLP-1RAs have shown positive CV outcomes. Furthermore, exenatide QW has been shown to be inferior to liraglutide and semaglutide with respect to HbA1c or body weight reduction in the head-to-head trials. Thus, although the long-term efficacy and safety of exenatide QW have been demonstrated, exenatide QW might be selected with lower priority within the class of GLP1-RAs for the management of T2DM, especially for patients at high CV risk. On the other hand, exenatide QW is now expected to be a treatment option for children with T2DM or patients with Parkinson’s disease. This review provides an overview of the current evidence regarding the clinical efficacy and safety of exenatide QW and discusses the current perspectives on exenatide QW for treatment of T2DM.

Safety and Efficacy of Exenatide Once Weekly in Participants with Type 2 Diabetes and Stage 2/3 Chronic Kidney Disease

INTRODUCTION

The safety and efficacy of exenatide once weekly (EQW) is overall well established. EQW is primarily renally eliminated. In this study, the efficacy and renal and gastrointestinal tolerability of EQW were summarised in participants with type 2 diabetes and chronic kidney disease stage 3 (CKD3; moderate renal impairment; estimated glomerular filtration rate [eGFR] ≥ 30 to < 60 mL/min/1.73 m²) or CKD stage 2 (CKD2; mild renal impairment; eGFR ≥ 60 to < 90 mL/min/1.73 m²).

METHODS

Data on participants with type 2 diabetes and baseline CKD3 or CKD2 from eight phase 3, double-blind or open-label studies with 26- or 28-week controlled treatment periods were pooled. Participants received EQW or a placebo/non-glucagon-like peptide-1 receptor agonist comparator (sitagliptin, metformin, pioglitazone, dapagliflozin and insulin).

RESULTS

Participants with baseline CKD3 (N = 182) or CKD2 (N = 772) receiving EQW differed in a number of baseline characteristics, such as age < 65 years, race, mean body mass index and mean type 2 diabetes duration, whereas mean blood pressure and glycated haemoglobin (HbA_1c) were similar. Mean reductions in HbA_1c, body weight and systolic blood pressure from baseline to week 26/28 in participants receiving EQW were similar between the CKD subgroups. The proportions of participants (CKD3 and CKD2) with any adverse event (AE) were 81% and 72%, respectively, for EQW and 74% and 68%, respectively, for all comparators; those for serious AEs were 2.7% and 3.4%, respectively, for EQW and 6% and 5%, respectively, for all comparators. Gastrointestinal AE rates were higher in the EQW CKD3 subgroup (42.2% of participants) than in the CKD2 (32.8%) subgroup, although rates for nausea and vomiting were similar. There were no dehydration events; one participant in each treatment group had a serious AE of acute kidney injury (EQW with CKD3, n = 1; pioglitazone with CKD2, n = 1).

CONCLUSION

Exenatide once weekly was well tolerated and demonstrated similar efficacy in participants with type 2 diabetes with mild and moderate renal impairment.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers: NCT00637273, NCT00676338, NCT02229383, NCT02229396, NCT00641056, NCT01652729, NCT00935532, NCT01003184.

Metformin monotherapy for adults with type 2 diabetes mellitus

BACKGROUND

Worldwide, there is an increasing incidence of type 2 diabetes mellitus (T2DM). Metformin is still the recommended first-line glucose-lowering drug for people with T2DM. Despite this, the effects of metformin on patient-important outcomes are still not clarified.

OBJECTIVES

To assess the effects of metformin monotherapy in adults with T2DM.

SEARCH METHODS

We based our search on a systematic report from the Agency for Healthcare Research and Quality, and topped-up the search in CENTRAL, MEDLINE, Embase, WHO ICTRP, and ClinicalTrials.gov. Additionally, we searched the reference lists of included trials and systematic reviews, as well as health technology assessment reports and medical agencies. The date of the last search for all databases was 2 December 2019, except Embase (searched up 28 April 2017).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with at least one year's duration comparing metformin monotherapy with no intervention, behaviour changing interventions or other glucose-lowering drugs in adults with T2DM.

DATA COLLECTION AND ANALYSIS

Two review authors read all abstracts and full-text articles/records, assessed risk of bias, and extracted outcome data independently. We resolved discrepancies by involvement of a third review author. For meta-analyses we used a random-effects model with investigation of risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the overall certainty of the evidence by using the GRADE instrument.

MAIN RESULTS

We included 18 RCTs with multiple study arms (N = 10,680). The percentage of participants finishing the trials was approximately 58% in all groups. Treatment duration ranged from one to 10.7 years. We judged no trials to be at low risk of bias on all 'Risk of bias' domains. The main outcomes of interest were all-cause mortality, serious adverse events (SAEs), health-related quality of life (HRQoL), cardiovascular mortality (CVM), non-fatal myocardial infarction (NFMI), non-fatal stroke (NFS), and end-stage renal disease (ESRD). Two trials compared metformin (N = 370) with insulin (N = 454). Neither trial reported on all-cause mortality, SAE, CVM, NFMI, NFS or ESRD. One trial provided information on HRQoL but did not show a substantial difference between the interventions. Seven trials compared metformin with sulphonylureas. Four trials reported on all-cause mortality: in three trials no participant died, and in the remaining trial 31/1454 participants (2.1%) in the metformin group died compared with 31/1441 participants (2.2%) in the sulphonylurea group (very low-certainty evidence). Three trials reported on SAE: in two trials no SAE occurred (186 participants); in the other trial 331/1454 participants (22.8%) in the metformin group experienced a SAE compared with 308/1441 participants (21.4%) in the sulphonylurea group (very low-certainty evidence). Two trials reported on CVM: in one trial no CVM was observed and in the other trial 4/1441 participants (0.3%) in the metformin group died of cardiovascular reasons compared with 8/1447 participants (0.6%) in the sulphonylurea group (very low-certainty evidence). Three trials reported on NFMI: in two trials no NFMI occurred, and in the other trial 21/1454 participants (1.4%) in the metformin group experienced a NFMI compared with 15/1441 participants (1.0%) in the sulphonylurea group (very low-certainty evidence). One trial reported no NFS occurred (very low-certainty evidence). No trial reported on HRQoL or ESRD. Seven trials compared metformin with thiazolidinediones (very low-certainty evidence for all outcomes). Five trials reported on all-cause mortality: in two trials no participant died; the overall RR was 0.88, 95% CI 0.55 to 1.39; P = 0.57; 5 trials; 4402 participants). Four trials reported on SAE, the RR was 0,95, 95% CI 0.84 to 1.09; P = 0.49; 3208 participants. Four trials reported on CVM, the RR was 0.71, 95% CI 0.21 to 2.39; P = 0.58; 3211 participants. Three trial reported on NFMI: in two trials no NFMI occurred and in one trial 21/1454 participants (1.4%) in the metformin group experienced a NFMI compared with 25/1456 participants (1.7%) in the thiazolidinedione group. One trial reported no NFS occurred. No trial reported on HRQoL or ESRD. Three trials compared metformin with dipeptidyl peptidase-4 inhibitors (one trial each with saxagliptin, sitagliptin, vildagliptin with altogether 1977 participants). There was no substantial difference between the interventions for all-cause mortality, SAE, CVM, NFMI and NFS (very low-certainty evidence for all outcomes). One trial compared metformin with a glucagon-like peptide-1 analogue (very low-certainty evidence for all reported outcomes). There was no substantial difference between the interventions for all-cause mortality, CVM, NFMI and NFS. One or more SAEs were reported in 16/268 (6.0%) of the participants allocated to metformin compared with 35/539 (6.5%) of the participants allocated to a glucagon-like peptide-1 analogue. HRQoL or ESRD were not reported. One trial compared metformin with meglitinide and two trials compared metformin with no intervention. No deaths or SAEs occurred (very low-certainty evidence) no other patient-important outcomes were reported. No trial compared metformin with placebo or a behaviour changing interventions. Four ongoing trials with 5824 participants are likely to report one or more of our outcomes of interest and are estimated to be completed between 2018 and 2024. Furthermore, 24 trials with 2369 participants are awaiting assessment.

AUTHORS' CONCLUSIONS

There is no clear evidence whether metformin monotherapy compared with no intervention, behaviour changing interventions or other glucose-lowering drugs influences patient-important outcomes.

HYPOTHYROIDISM COULD BE A POTENTIAL FACTOR TO PROLONG SUBCUTANEOUS NODULES OF EXENATIDE ONCE WEEKLY: A CASE REPORT

Objective

Exenatide once weekly (ExeOW) is one of the long-acting glucagon-like peptide 1 receptor agonists. Embedding exenatide in poly(D,L-lactide-co-glycolide) microspheres enables the once-weekly subcutaneous injection of exenatide as a treatment for diabetes. We report a case of a patient with type 2 diabetes and hypothyroidism who developed long-standing subcutaneous nodules after treatment by ExeOW injection.

Methods

Case report and review of the literature. A 57-year-old Japanese man with type 2 diabetes treated with ExeOW and primary hypothyroidism.

Results

We observed multiple subcutaneous nodules remaining at the ExeOW injection site for >10 weeks. As the patient's thyroid hormone levels normalized, these nodules decreased and disappeared, and his hemoglobin A1c levels improved.

Conclusion

The patient's clinical course suggests that the hydrolysis of ExeOW at the site of injection may be inhibited by concomitant hypothyroidism, in which glycosaminoglycans including hyaluronic acid are known to accumulate (including in the skin). This case may indicate that hypothyroidism prolongs the existence of subcutaneous nodules from ExeOW treatment.

Review of glucagon-like peptide-1 receptor agonists for the treatment of type 2 diabetes mellitus in patients with chronic kidney disease and their renal effects

Type 2 diabetes mellitus (T2DM) is the most common cause of chronic kidney disease (CKD), and when it causes CKD it is collectively referred to as diabetic kidney disease. One of the newer therapies for managing hyperglycemia is the glucagon-like peptide-1 receptor agonist (GLP-1RA) drug class. This review summarizes the effects of GLP-1RAs in patients with T2DM with CKD and evidence for renoprotection with GLP-1RAs using data from observational studies, prospective clinical trials, post hoc analyses, and meta-analyses. Evidence from some preclinical studies was also reviewed. Taken together, subgroup analyses of patients with varying degrees of renal function demonstrated that glycemic control with GLP-1RAs was not markedly less effective in patients with mild or moderate renal impairment vs that in patients with normal function. GLP-1RAs were associated with improvements in some cardiorenal risk factors, including systolic blood pressure and body weight. Furthermore, several large cardiovascular outcome studies showed reduced risks of composite renal outcomes, mostly driven by a reduction in macroalbuminuria, suggesting potential renoprotective effects of GLP-1RAs. In conclusion, GLP-1RAs effectively reduced hyperglycemia in patients with mild or moderately impaired kidney function in the limited number of studies to date. GLP-1RAs may be considered in combination with other glucose-lowering medications because of their ability to lower glucose in a glucose-dependent manner, lowering their risk for hypoglycemia, while improving some cardiorenal risk factors. Potential renoprotective effects of GLP-1RAs, and their renal mechanisms of action, warrant further investigation.

The Relevance of Insulin Action in the Dopaminergic System

The advances in medicine, together with lifestyle modifications, led to a rising life expectancy. Unfortunately, however, aging is accompanied by an alarming boost of age-associated chronic pathologies, including neurodegenerative and metabolic diseases. Interestingly, a non-negligible interplay between alterations of glucose homeostasis and brain dysfunction has clearly emerged. In particular, epidemiological studies have pointed out a possible association between Type 2 Diabetes (T2D) and Parkinson’s Disease (PD). Insulin resistance, one of the major hallmark for etiology of T2D, has a detrimental influence on PD, negatively affecting PD phenotype, accelerating its progression and worsening cognitive impairment. This review aims to provide an exhaustive analysis of the most recent evidences supporting the key role of insulin resistance in PD pathogenesis. It will focus on the relevance of insulin in the brain, working as pro-survival neurotrophic factor and as a master regulator of neuronal mitochondrial function and oxidative stress. Insulin action as a modulator of dopamine signaling and of alpha-synuclein degradation will be described in details, too. The intriguing idea that shared deregulated pathogenic pathways represent a link between PD and insulin resistance has clinical and therapeutic implications. Thus, ongoing studies about the promising healing potential of common antidiabetic drugs such as metformin, exenatide, DPP IV inhibitors, thiazolidinediones and bromocriptine, will be summarized and the rationale for their use to decelerate neurodegeneration will be critically assessed.

Pancreatitis Incidence in the Exenatide BID, Exenatide QW, and Exenatide QW Suspension Development Programs: Pooled Analysis of 35 Clinical Trials

INTRODUCTION

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are widely used for treatment of type 2 diabetes mellitus; however, there have been concerns that GLP-1RA treatment may be associated with an increased incidence of pancreatitis. This study aimed to evaluate the incidence of pancreatitis in a pooled population of type 2 diabetes trials from the clinical development program of the GLP-1RA exenatide as well as to describe patient-level data for all reported cases.

METHODS

The primary analysis examined pooled data among patients with type 2 diabetes from the controlled arms of 35 trials (ranging from 4 to 234 weeks' duration) in the integrated clinical databases for exenatide twice daily, once weekly, and once-weekly suspension, excluding comparator arms with other incretin-based therapies. The exposure-adjusted incidence rate (EAIR) of pancreatitis was calculated for exenatide and non-exenatide (non-incretin-based therapy or placebo) treatment groups. Patient-level data were described for all pancreatitis incidences.

RESULTS

The primary analysis included 5596 patients who received exenatide and 4462 in the non-exenatide group. The mean duration of study medication exposure for the exenatide and non-exenatide treatment groups was 57.0 and 47.9 weeks, respectively. Pancreatitis was diagnosed in 14 patients (exenatide, n = 8; non-exenatide, n = 6), of whom 13 recovered with or without sequelae. The pancreatitis EAIR was 0.1195 events per 100 patient-years [95% confidence interval (CI), 0.0516-0.2154] in the exenatide group versus 0.1276 events per 100 patient-years (95% CI 0.0468-0.2482) in the non-exenatide treatment group. The EAIR ratio for the exenatide versus non-exenatide treatment group was 0.761 (95% CI 0.231-2.510).

CONCLUSION

In this pooled analysis of 10,058 patients among studies comparing exenatide with other glucose-lowering medications or placebo, pancreatitis was rare. The EAIRs of pancreatitis were low and similar between exenatide and non-exenatide treatment groups. No evidence of an association between exenatide and pancreatitis was observed.

FUNDING

Bristol-Myers Squibb and AstraZeneca. Plain language summary available for this article.

Structural Changes Observed in the Piriform Cortex in a Rat Model of Pre-motor Parkinson's Disease

Early diagnosis of Parkinson’s disease (PD) offers perhaps, the most promising route to a successful clinical intervention, and the use of an animal model exhibiting symptoms comparable to those observed in PD patients in the early stage of the disease, may facilitate screening of novel therapies for delaying the onset of more debilitating motor and behavioral abnormalities. In this study, a rat model of pre-motor PD was used to study the etiology of hyposmia, a non-motor symptom linked to the early stage of the disease when the motor symptoms have yet to be experienced. The study focussed on determining the effect of a partial reduction of both dopamine and noradrenaline levels on the olfactory cortex. Neuroinflammation and striking structural changes were observed in the model. These changes were prevented by treatment with a neuroprotective drug, a glucagon-like peptide-1 (GLP1) receptor agonist, exendin-4 (EX-4).

Pharmacokinetic drug evaluation of exenatide for the treatment of type 2 diabetes

INTRODUCTION

Glucagon-like peptide-1 (GLP-1) receptor analogs are a group of therapeutic agents which mimic endogenous GLP-1, exerting their effect by the stimulation of the GLP-1 receptor with a wide distribution. Its activation increases insulin releasing dependent on blood glucose levels, suppression of glucagon secretion and a reduction of hepatic glucose output. It delays gastric emptying and increases satiety. Exenatide is the synthetic version of exendin-4, a natural peptide with similar properties to human GLP-1. There are two pharmaceutical forms, for subcutaneous injection: twice daily and once weekly. Clinical practice guidelines recommend them because of a high efficacy reducing hyperglycemia, low risk of hypoglycemia and a significative weight loss effect. Gastrointestinal adverse events are the most common beside injection site-related. Their cost is the main limitation to use. Areas covered: We review the recent literature investigating the pharmacokinetics and pharmacodynamics and efficacy-safety studies of exenatide twice daily and once weekly in type 2 diabetes Expert opinion: GLP-1 receptor analogs are now positioned as an effective and safe drug for the treatment of type 2 diabetes. Exenatide significally reduces HbA1c and fasting plasma glucose. Additionally, it produces moderate weight loss and decreases blood pressure. One weekly formulation may improve compliance while cost is still a limitation. EXSCEL trial has shown that, despite cardiovascular safety, exenatide do not exhibits cardiovascular benefits.

Exenatide once weekly versus placebo in Parkinson's disease: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Exenatide, a glucagon-like peptide-1 (GLP-1) receptor agonist, has neuroprotective effects in preclinical models of Parkinson's disease. We investigated whether these effects would be apparent in a clinical trial.

METHODS

In this single-centre, randomised, double-blind, placebo-controlled trial, patients with moderate Parkinson's disease were randomly assigned (1:1) to receive subcutaneous injections of exenatide 2 mg or placebo once weekly for 48 weeks in addition to their regular medication, followed by a 12-week washout period. Eligible patients were aged 25-75 years, had idiopathic Parkinson's disease as measured by Queen Square Brain Bank criteria, were on dopaminergic treatment with wearing-off effects, and were at Hoehn and Yahr stage 2·5 or less when on treatment. Randomisation was by web-based randomisation with a two strata block design according to disease severity. Patients and investigators were masked to treatment allocation. The primary outcome was the adjusted difference in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) motor subscale (part 3) in the practically defined off-medication state at 60 weeks. All efficacy analyses were based on a modified intention-to-treat principle, which included all patients who completed any post-randomisation follow-up assessments. The study is registered at ClinicalTrials.gov (NCT01971242) and is completed.

FINDINGS

Between June 18, 2014, and March 13, 2015, 62 patients were enrolled and randomly assigned, 32 to exenatide and 30 to placebo. Our primary analysis included 31 patients in the exenatide group and 29 patients in the placebo group. At 60 weeks, off-medication scores on part 3 of the MDS-UPDRS had improved by 1·0 points (95% CI -2·6 to 0·7) in the exenatide group and worsened by 2·1 points (-0·6 to 4·8) in the placebo group, an adjusted mean difference of -3·5 points (-6·7 to -0·3; p=0·0318). Injection site reactions and gastrointestinal symptoms were common adverse events in both groups. Six serious adverse events occurred in the exenatide group and two in the placebo group, although none in either group were judged to be related to the study interventions.

INTERPRETATION

Exenatide had positive effects on practically defined off-medication motor scores in Parkinson's disease, which were sustained beyond the period of exposure. Whether exenatide affects the underlying disease pathophysiology or simply induces long-lasting symptomatic effects is uncertain. Exenatide represents a major new avenue for investigation in Parkinson's disease, and effects on everyday symptoms should be examined in longer-term trials.

FUNDING

Michael J Fox Foundation for Parkinson's Research.

Exenatide once weekly versus placebo in Parkinson's disease: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Exenatide, a glucagon-like peptide-1 (GLP-1) receptor agonist, has neuroprotective effects in preclinical models of Parkinson's disease. We investigated whether these effects would be apparent in a clinical trial.

METHODS

In this single-centre, randomised, double-blind, placebo-controlled trial, patients with moderate Parkinson's disease were randomly assigned (1:1) to receive subcutaneous injections of exenatide 2 mg or placebo once weekly for 48 weeks in addition to their regular medication, followed by a 12-week washout period. Eligible patients were aged 25-75 years, had idiopathic Parkinson's disease as measured by Queen Square Brain Bank criteria, were on dopaminergic treatment with wearing-off effects, and were at Hoehn and Yahr stage 2·5 or less when on treatment. Randomisation was by web-based randomisation with a two strata block design according to disease severity. Patients and investigators were masked to treatment allocation. The primary outcome was the adjusted difference in the Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) motor subscale (part 3) in the practically defined off-medication state at 60 weeks. All efficacy analyses were based on a modified intention-to-treat principle, which included all patients who completed any post-randomisation follow-up assessments. The study is registered at ClinicalTrials.gov (NCT01971242) and is completed.

FINDINGS

Between June 18, 2014, and March 13, 2015, 62 patients were enrolled and randomly assigned, 32 to exenatide and 30 to placebo. Our primary analysis included 31 patients in the exenatide group and 29 patients in the placebo group. At 60 weeks, off-medication scores on part 3 of the MDS-UPDRS had improved by 1·0 points (95% CI -2·6 to 0·7) in the exenatide group and worsened by 2·1 points (-0·6 to 4·8) in the placebo group, an adjusted mean difference of -3·5 points (-6·7 to -0·3; p=0·0318). Injection site reactions and gastrointestinal symptoms were common adverse events in both groups. Six serious adverse events occurred in the exenatide group and two in the placebo group, although none in either group were judged to be related to the study interventions.

INTERPRETATION

Exenatide had positive effects on practically defined off-medication motor scores in Parkinson's disease, which were sustained beyond the period of exposure. Whether exenatide affects the underlying disease pathophysiology or simply induces long-lasting symptomatic effects is uncertain. Exenatide represents a major new avenue for investigation in Parkinson's disease, and effects on everyday symptoms should be examined in longer-term trials.

FUNDING

Michael J Fox Foundation for Parkinson's Research.

Long-term management of type 2 diabetes with glucagon-like peptide-1 receptor agonists

Continuously reducing excess blood glucose is a primary goal for the management of type 2 diabetes (T2D). Most patients with T2D require glucose-lowering medications to achieve and maintain adequate glycemic control; however, treatment failure may occur, limiting treatment options. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are an emerging therapeutic class that can be prescribed for patients instead of basal insulin after the failure of oral therapies. Recent studies have focused on the durability and tolerability of long-term GLP-1RA therapy. This review summarizes the key efficacy and safety findings from prospective phase 3 clinical studies of at least 76 weeks' duration for the GLP-1RAs currently approved in the United States and the European Union (albiglutide, dulaglutide, exenatide twice daily [BID], exenatide once weekly [QW], liraglutide, and lixisenatide). Currently, most of the long-term data are from uncontrolled extension studies, and continuous patient benefit has been observed for up to 3 years with multiple GLP-1RAs. Four-year comparative data demonstrated a longer time to treatment failure for exenatide BID than for sulfonylurea, and 3-year comparative extension data demonstrated greater glycated hemoglobin (HbA1c) reductions and weight loss with exenatide QW than with insulin glargine. Currently, the longest extension study for a GLP-1RA is the DURATION-1 study of exenatide QW, with >7 years of clinical data available. Data from DURATION-1 demonstrated that continuous HbA1c reductions and weight loss were observed for the patients continuing on the treatment, with no unexpected adverse events. Taken together, these data support GLP-1RAs as a long-term noninsulin treatment option after the failure of oral therapies.

Exenatide once weekly improved 24-hour glucose control and reduced glycaemic variability in metformin-treated participants with type 2 diabetes: a randomized, placebo-controlled trial

AIM

To assess the effects of once-weekly exenatide on 24-hour glucose control and variability.

MATERIALS AND METHODS

This double-blind, placebo-controlled trial randomized metformin-treated adults with type 2 diabetes to once-weekly exenatide 2.0 mg or placebo. Continuous glucose monitoring (CGM) was performed at baseline and weeks 4 and 10. The primary outcome was change in CGM-measured 24-hour mean glucose level.

RESULTS

In the once-weekly exenatide (n = 60) and placebo (n = 56) groups (modified intention-to-treat population), the baseline glycated haemoglobin (HbA1c) concentrations were 8.2% and 8.0%, respectively, and the fasting plasma glucose (FPG) concentration was 9.86 and 9.32 mmol/L, respectively. Once-weekly exenatide significantly (p < 0.001) reduced 24-hour mean glucose level versus placebo (week 4, -1.44 vs -0.29 mmol/L; week 10, -1.71 vs -0.17 mmol/L), with consistent control throughout the week. Once-weekly exenatide significantly reduced FPG and 2-hour postprandial glucose (PPG) levels versus placebo at week 4 (FPG, -1.65 vs -0.11 mmol/L; PPG, -1.79 vs -0.11 mmol/L) and week 10 (FPG, -2.32 vs -0.28 mmol/L; PPG, -2.46 vs -0.33 mmol/L). At week 10, once-weekly exenatide reduced the mean amplitude of glucose excursions (MAGE; -0.84 vs 0.16 mmol/L) and standard deviation (s.d.) of mean glucose (-0.35 vs 0.04 mmol/L). By week 10, once-weekly exenatide-treated participants spent more time in euglycaemia (once-weekly exenatide, 77% vs placebo, 58%), less time in hyperglycaemia (22% vs 42%), and a similar time in hypoglycaemia (0.7% vs 0.3%). Common adverse events were injection-site nodule (once-weekly exenatide, 10.0% vs placebo, 0.0%), urinary tract infection (6.7% vs 8.9%) and nausea (6.7% vs 0.0%).

CONCLUSIONS

In metformin-treated participants with type 2 diabetes, once-weekly exenatide significantly improved daily glucose control and reduced glycaemic variability at weeks 4 and 10, as shown by reductions in 24-hour glucose, FPG and PPG levels, MAGE and s.d., and increased time spent in euglycaemia.

Efficacy and Tolerability of Exenatide Once Weekly Over 6 Years in Patients with Type 2 Diabetes: An Uncontrolled Open-Label Extension of the DURATION-1 Study

BACKGROUND

Long-term treatment is necessary to slow the progression of type 2 diabetes (T2D). Here, we examined the safety and efficacy of 6 years of treatment with exenatide once weekly (QW) among patients with T2D in the DURATION-1 trial.

METHODS

The study enrolled patients aged ≥16 years with T2D treated primarily with metformin and sulfonylureas. Following 30 weeks of randomized treatment with exenatide QW 2 mg or exenatide twice daily 10 μg, patients entered an uncontrolled, open-label, open-ended study phase in which all patients received exenatide QW 2 mg. Restrictions on concomitant medication use were eased over time.

RESULTS

Of the original 295 patients in the intent-to-treat population, 136 (46%) completed 6 years of treatment. Six-year completers had sustained significant improvements from baseline in glycated hemoglobin (HbA1c; least-squares mean [LSM] change, -1.6%), with 46.3% achieving HbA1c <7.0%, 33.1% achieving HbA1c ≤6.5%, and significant improvements from baseline in fasting plasma glucose (-28 mg/dL) and body weight (-4.2 kg) at 6 years. The 78 completers who added no glucose-lowering medications had numerically greater body weight reductions than the overall cohort (6-year LSM change, -6.1 kg) with more stability over time. No unexpected adverse events were observed during 1202.4 patient-years of exposure. Most minor hypoglycemia events occurred with concomitant sulfonylurea use.

CONCLUSIONS

Exenatide QW was associated with clinically significant, sustained improvements in glycemic control and weight in patients who continued therapy for up to 6 years, without unexpected safety findings. ClinicalTrials.gov registration: NCT00308139.

Albiglutide: a unique GLP-1 receptor agonist

INTRODUCTION

Albiglutide is a long acting GLP-1 receptor agonist (GLP-1 RA) administered by weekly injection. Area covered: The pharmacokinetic and pharmacodynamic properties of albiglutide and its clinical effects are discussed. The review encompassed a search of PubMed and a thorough analysis of the European Union and US Food and Drug Administration approval documents. Expert opinion: Albiglutide has a chemical structure quite distinct from that of other marketed GLP-1 RAs. The agent has less gastrointestinal side effects than other comparable GLP-1 RAs and is safe in patients with renal failure. As a sole treatment for diabetes and used with other hypoglycemic agents, it achieves a lowering of HbA1c of up to 1%, less than several competitor GLP-1 RAs. The benefit on weight reduction is minimal compared to other GLP-1 RAs. There exists concern about an imbalance of pancreatitis cases in the approval program as well as injection site reactions which led to discontinuance of therapy in up to 2% of participants. A large long term study now underway will determine if albiglutide, with its lower level of GI intolerance, has a place in the treatment of patients with increased risk of cardiovascular events.

Onset of Glycemic and Weight Outcomes in Patients Initiating Exenatide Once Weekly: The Relationship of Exenatide Exposure with Efficacy over the First 24 Weeks of Treatment

INTRODUCTION

Exenatide is gradually released from exenatide once weekly (QW) microspheres, and at steady state, consistently controls glycated hemoglobin (HbA1c) in patients with type 2 diabetes (T2D). This post hoc analysis examined the timing to onset of clinical responses and their correlations with exenatide concentrations after initiation of exenatide QW in patients with T2D.

METHODS

Trial data were retrospectively analyzed to explore the early clinical responses to exenatide QW, including the relationship of exenatide concentration with its effects on efficacy [fasting plasma glucose (FPG), HbA1c, and body weight] and tolerability (nausea and vomiting). Exenatide QW efficacy and tolerability data were from DURATION-5, a 24-week, randomized, comparator-controlled trial [intent-to-treat (ITT) population]. Exenatide concentrations were measured in a patient subset (pharmacokinetic population).

RESULTS

In the ITT (n = 129)/pharmacokinetic (n = 72) populations, baseline FPG, HbA1c, and body weight were 173/173 mg/dL, 8.5%/8.4%, and 97/98 kg, respectively. Exenatide concentrations gradually increased until reaching steady state at week 8. By week 4, the FPG reduction (-32.4 mg/dL) was 94% of the week 24 reduction (-34.6 mg/dL). Reductions in HbA1c began by week 4 (-0.6%) and stabilized by week 14 (week 24: -1.6%). Weight reduction at week 4 was -0.7 kg and decreased further (week 24: -2.3 kg). Peak nausea (7.2%) and vomiting (2.4%) occurred at weeks 6-8, declining thereafter.

CONCLUSION

Clinically relevant responses to exenatide QW were evident by week 4, after exenatide concentration passed the therapeutic threshold but before steady state was achieved.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00877890.

FUNDING

AstraZeneca.

Exenatide Extended-Release: An Updated Review of Its Use in Type 2 Diabetes Mellitus

Exenatide extended-release (exenatide ER) [Bydureon(®)] is a glucagon-like peptide-1 receptor agonist, approved for the treatment of type 2 diabetes mellitus. It is injected subcutaneously by patients once weekly, with no dose titration required. This article updates an earlier review of exenatide ER in the management of type 2 diabetes, focusing on recently published data. In randomized, controlled trials, adjunctive exenatide ER 2 mg once weekly for 24-30 weeks significantly improved glycaemic control and reduced bodyweight in patients with inadequately controlled type 2 diabetes despite diet plus exercise and/or oral antihyperglycaemic drugs (OADs). These beneficial effects of exenatide ER were maintained after up to 6 years of treatment. In patients receiving one or more OADs, addition of exenatide ER provided better glycaemic control than an immediate-release formulation of exenatide (exenatide twice daily), sitagliptin, pioglitazone, insulin glargine or insulin detemir, and was slightly less effective than liraglutide. In patients treated with diet plus exercise alone, adjunctive exenatide ER was noninferior to metformin and superior to sitagliptin, but was not noninferior to pioglitazone. Exenatide ER was generally well tolerated, with a low inherent risk of hypoglycaemia. The most common adverse events were mild to moderate gastrointestinal events, injection-site reactions and headache. Thus, exenatide ER is a useful treatment option in the management of type 2 diabetes. It offers a convenient, once-weekly regimen and can be administered by patients via a pen injection system or syringes and needles.

A Network Meta-analysis Comparing Exenatide Once Weekly with Other GLP-1 Receptor Agonists for the Treatment of Type 2 Diabetes Mellitus

INTRODUCTION

Exenatide is a glucagon-like peptide-1 receptor agonist (GLP-1 RA), approved for treatment of type 2 diabetes mellitus (T2DM). There is limited direct evidence comparing the efficacy and tolerability of exenatide 2 mg once weekly (QW) to other GLP-1 RAs. A network meta-analysis (NMA) was conducted to estimate the relative efficacy and tolerability of exenatide QW versus other GLP-1 RAs for the treatment of adults with T2DM inadequately controlled on metformin monotherapy.

METHODS

A systematic literature review was conducted to identify randomized controlled trials (RCTs) that investigated GLP-1 RAs (albiglutide, dulaglutide, exenatide, liraglutide, and lixisenatide) at approved doses in the United States/Europe, added on to metformin only and of 24 ± 6 weeks treatment duration. A Bayesian NMA was conducted.

RESULTS

Fourteen RCTs were included in the NMA. Exenatide QW obtained a statistically significant reduction in glycated hemoglobin (HbA1c) relative to lixisenatide 20 µg once daily. No other comparisons of exenatide QW to other GLP-1 RAs were statistically significant for change in HbA1c. No statistically significant differences in change in weight, systolic blood pressure, risk of nausea or discontinuation due to adverse events were observed for exenatide QW versus other GLP-1 RAs.

CONCLUSION

Exenatide QW demonstrated similar effectiveness and tolerability compared to other GLP-1 RAs, for the treatment of T2DM in adults inadequately controlled on metformin alone.

No evidence of drug-induced pancreatitis in rats treated with exenatide for 13 weeks

AIMS

The potential association of glucagon-like peptide receptor agonists (GLP-1RAs) with the development of pancreatitis or pancreatic malignancies in patients with diabetes has been suggested. This study evaluated the long-term effects of the GLP-1RA exenatide on pancreatic exocrine structure and function in the Zucker diabetic fatty (ZDF) rat model of type 2 diabetes.

METHODS

Rats received subcutaneous twice-daily injections of 0 (control), 6, 40 and 250 µg/kg/day exenatide for 3 months. Clinical signs, body and pancreas weight, food consumption, HbA1c, fasting serum amylase, lipase, glucose and insulin concentrations were evaluated during treatment and after a 28-day off-drug period to assess the reversibility of any observed effects. Morphometric analysis of pancreatic ductal cell proliferation and apoptosis were performed.

RESULTS

Plasma exenatide concentrations were several-fold higher than therapeutic levels observed in humans. No exenatide-related effects were observed on clinical signs, lipase concentration, pancreatic weight, pancreatic histology, ductal cell proliferation or apoptosis. Exenatide improved animal survival, physical condition, glucose concentrations and HbA1c, decreased food intake, and increased serum insulin concentration. Total amylase concentrations, although within normal ranges, were slightly higher in exenatide-treated rats; following the off-drug period, total amylase concentrations were comparable in treated and untreated rats. Exenatide-related minimal-to-moderate islet hypertrophy was observed at doses ≥6 µg/kg/day, with dose-related increases in incidence and degree. These changes were still present after the off-drug period.

CONCLUSIONS

Chronic administration of exenatide in ZDF rats resulted in the expected metabolic benefits and improved animal survival, with no adverse effects noted on pancreatic exocrine structure and function.