A placebo-controlled trial of exenatide twice-daily added to thiazolidinediones alone or in combination with metformin

Efficacy of GLP-1 receptor agonists and DPP-4 inhibitors: meta-analysis and systematic review

BACKGROUND

Considerable clinical data on the treatment of type 2 diabetes with incretin-based therapies (glucagon-like peptide 1 receptor agonists [GLP-1RAs] and dipeptidyl-peptidase IV [DPP-4] inhibitors) are available.

OBJECTIVE

This meta-analysis was performed to support the understanding of the overall evidence by summarizing the findings from studies of the incretin-based therapies.

METHODS

The MEDLINE, EMBASE, BIOSIS, and BIOSIS trial databases were searched for relevant literature published between January 1, 1990, and June 30, 2011. Search terms included GLP-1, DPP-4, the names of drugs that have been approved by the US Food and Drug Administration for the treatment of diabetes, and the names of drugs that have not been approved but are in late-stage research. Studies were included if they were randomized controlled trials of 12 to 52 weeks' duration and having change from baseline in hemoglobin (Hb) A(1c) as the primary end point. The random effects meta-analyses models examined HbA(1c), fasting plasma glucose (FPG), and body weight for individual therapies, but did not compare effects between therapies.

RESULTS

The reviewers identified 362 unique clinical studies, of which 80 were eligible for inclusion in the present meta-analysis. Mean baseline HbA(1c) values ranged from 7.4% to 10.3% (GLP-1RA studies) and 7.2% to 9.3% (DPP-4 inhibitor studies). The highest maintenance doses of the GLP-1RAs and the DPP-4 inhibitors were associated with changes from baseline in mean HbA(1c) of -1.1% to -1.6% and -0.6% to -1.1%, respectively. Mean reductions in FPG with exenatide once weekly (QW) or liraglutide once daily were apparently greater than those with exenatide twice daily (BID) and the DPP-4 inhibitors, with the exception of vildagliptin. Mean weight losses with the GLP-1RAs and the DPP-4 inhibitors were >-2.0 and -0.2 to -0.6 kg, respectively. The limitations of the present analysis included a lack of adjustment for placebo use and interstudy heterogeneity associated with differences in methodology (eg, management of concurrent medications, blinding, criteria for treatment discontinuation).

CONCLUSIONS

All of the incretin-based therapies in the present meta-analysis were associated with significant reductions from baseline in HbA(1c) and FPG. Further direct comparative studies between the GLP-1RAs and the DPP-4 inhibitors and within the GLP-1RA class are justified.

The role of self-monitoring of blood glucose in glucagon-like peptide-1-based treatment approaches: a European expert recommendation

The role of glucagon-like peptide (GLP)-1-based treatment approaches for type 2 diabetes mellitus (T2DM) is increasing. Although self-monitoring of blood glucose (SMBG) has been performed in numerous studies on GLP-1 analogs and dipeptidyl peptidase-4 inhibitors, the potential role of SMBG in GLP-1-based treatment strategies has not been elaborated. The expert recommendation suggests individualized SMBG strategies in GLP-1-based treatment approaches and suggests simple and clinically applicable SMBG schemes. Potential benefits of SMBG in GLP-1-based treatment approaches are early assessment of treatment success or failure, timely modification of treatment, detection of hypoglycemic episodes, assessment of glucose excursions, and support of diabetes management and diabetes education. Its length and frequency should depend on the clinical setting and the quality of metabolic control. It is considered to play an important role for the optimization of diabetes management in T2DM patients treated with GLP-1-based approaches.

Efficacy and safety of exenatide once weekly versus metformin, pioglitazone, and sitagliptin used as monotherapy in drug-naive patients with type 2 diabetes (DURATION-4): a 26-week double-blind study

OBJECTIVE

To test the safety and efficacy of exenatide once weekly (EQW) compared with metformin (MET), pioglitazone (PIO), and sitagliptin (SITA) over 26 weeks, in suboptimally treated (diet and exercise) drug-naive patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Patients were randomized to subcutaneous (SC) EQW 2.0 mg + oral placebo (n = 248), MET 2,000 mg/day + SC placebo (n = 246), PIO 45 mg/day + SC placebo (n = 163), or SITA 100 mg/day + SC placebo (n = 163) for 26 weeks. MET and PIO therapies were increased to maximum-tolerated dosages. Injections with EQW or placebo were administered weekly, while oral medication or placebo was administered daily.

RESULTS

Baseline characteristics were as follows: 59% men, 67% Caucasian, mean age 54 years, HbA(1c) 8.5%, fasting serum glucose 9.9 mmol/L, body weight 87.0 kg, and diabetes duration 2.7 years. HbA(1c) reductions (%) at 26 weeks (least-squares means) with EQW versus MET, PIO, and SITA were -1.53 vs. -1.48 (P = 0.620), -1.63 (P = 0.328), and -1.15 (P < 0.001), respectively. Weight changes (kg) were -2.0 vs. -2.0 (P = 0.892), +1.5 (P < 0.001), and -0.8 (P < 0.001), respectively. Common adverse events were as follows: EQW, nausea (11.3%) and diarrhea (10.9%); MET, diarrhea (12.6%) and headache (12.2%); PIO, nasopharyngitis (8.6%) and headache (8.0%); and SIT, nasopharyngitis (9.8%) and headache (9.2%). Minor (confirmed) hypoglycemia was rarely reported. No major hypoglycemia occurred.

CONCLUSIONS

EQW was noninferior to MET but not PIO and superior to SITA with regard to HbA(1c) reduction at 26 weeks. Of the agents studied, EQW and MET provided similar improvements in glycemic control along with the benefit of weight reduction and no increased risk of hypoglycemia.

Safety and tolerability of exenatide twice daily in patients with type 2 diabetes: integrated analysis of 5594 patients from 19 placebo-controlled and comparator-controlled clinical trials

BACKGROUND

Exenatide twice daily is a first-in-class glucagon-like peptide receptor agonist approved for the treatment of type 2 diabetes. The objective of this analysis was to evaluate the safety profile of exenatide twice daily and to compare its profile with that of a pooled comparator (placebo and insulin) in patients with type 2 diabetes.

METHODS

Data from 19 completed, randomized, controlled clinical trials of exenatide twice daily (5 μg and 10 μg) were pooled and analyzed; the pooled data included 5594 intent-to-treat patients who were followed for 12-52 weeks. Incidence rates, exposure-adjusted incidence rates, and 95% confidence intervals around risk differences between groups were calculated.

RESULTS

Baseline demographics and exposure time were comparable between groups (exenatide, N = 3261; pooled comparator, N = 2333; mean exposure time 166-171 days). Transient, mild- to-moderate nausea was the most frequent adverse event with exenatide (36.9% versus 8.3% in the pooled comparator). The incidence of hypoglycemia (minor or major) with concomitant sulfonylurea (exenatide 26.5%, pooled comparator 20.7%) was higher than that without sulfonylurea (exenatide 3.1%, pooled comparator 2.7%) in all groups. Serious adverse events, discontinuations due to serious adverse events, and deaths were reported with similar frequency in the exenatide and pooled comparator groups. Composite exposure-adjusted incidence rates were not statistically different between groups for pancreatitis, renal impairment, or major adverse cardiac events; there was a difference in incidence rates for benign thyroid neoplasm (0.3% versus 0%).

CONCLUSION

Overall, this analysis, representing over 1500 patient-years of exposure, demonstrated that exenatide twice daily was safe and generally well tolerated in patients with type 2 diabetes. The incidence of most adverse events, including serious adverse events, was similar in both exenatide-treated and comparator-treated patients. The most distinct differences between groups were in gastrointestinal-related adverse events, which is consistent with other therapies within the glucagon-like peptide class.

Exenatide, a GLP-1 agonist in the treatment of Type 2 diabetes

Incretin-based therapies represent a new and innovative treatment modality in the management of Type 2 diabetes. Their therapeutic actions address many of the key metabolic defects in the pathophysiology of diabetes. Incretin hormones augment insulin secretion in a glucose-dependent manner. They have a low risk of inducing hypoglycemia, unlike many other antidiabetic medications. They also have the beneficial effect of being associated with early satiety, decreased caloric intake and weight loss. Exenatide was the first incretin-based therapy to be licensed for use and has now been developed in a once-weekly preparation. We review the evidence base for the use of exenatide and discuss the implications for the management of diabetes.

Consensus report: the current role of self-monitoring of blood glucose in non-insulin-treated type 2 diabetes

The Coalition for Clinical Research--Self-Monitoring of Blood Glucose Scientific Board convened a meeting in San Francisco, CA, July 20-21, 2011, to discuss the current practice of self-monitoring of blood glucose (SMBG) in non-insulin-treated (NIT) type 2 diabetes mellitus (T2DM). Twelve physician panel members from academia, practice, and government attended this meeting. These experts came from the United States, Brazil, Canada, France, Germany, Italy, and the United Kingdom. In addition, three consultants from Australia, Germany, and the United States contributed to the group's final report. This coalition was organized by Diabetes Technology Society. Self-monitoring of blood glucose was studied from eight perspectives related to patients with NIT T2DM: (1) epidemiological studies; (2) randomized controlled trials (RCT)s and meta-analyses; (3) targets, timing, and frequency of SMBG use; (4) incidence and role of SMBG in preventing hypoglycemia with single-drug regimens and combination regimens consisting of antihyperglycemic agents other than secretagogues and insulin; (5) comparison of SMBG with continuous glucose monitoring; (6) technological capabilities and limitations of SMBG; (7) barriers to appropriate use of SMBG; and (8) methods and end points for appropriate future clinical trials. The panel emphasized recent studies, which reflect the current approach for applying this intervention. Among the participants there was consensus that: SMBG is an established practice for patients with NIT T2DM, and to be most effective, it should be performed in a structured format where information obtained from this measurement is used to guide treatment; New, high-quality efficacy data from RCTs have demonstrated efficacy of SMBG in NIT T2DM in trials reported since 2008; Both patients and health care professionals require education on how to respond to the data for SMBG to be effective; and Additional well-defined studies are needed to assess the benefits and costs of SMBG with end points not limited to hemoglobin A1c.

Glucagon-like peptide-1 receptor agonists and cardiovascular events: a meta-analysis of randomized clinical trials

Objective. Data from randomized clinical trials with metabolic outcomes can be used to address concerns about potential issues of cardiovascular safety for newer drugs for type 2 diabetes. This meta-analysis was designed to assess cardiovascular safety of GLP-1 receptor agonists. Design and Methods. MEDLINE, Embase, and Cochrane databases were searched for randomized trials of GLP-1 receptor agonists (versus placebo or other comparators) with a duration ≥12 weeks, performed in type 2 diabetic patients. Mantel-Haenszel odds ratio with 95% confidence interval (MH-OR) was calculated for major cardiovascular events (MACE), on an intention-to-treat basis, excluding trials with zero events. Results. Out of 36 trials, 20 reported at least one MACE. The MH-OR for all GLP-1 receptor agonists was 0.74 (0.50–1.08), P = .12 (0.85 (0.50–1.45), P = .55, and 0.69 (0.40–1.22), P = .20, for exenatide and liraglutide, resp.). Corresponding figures for placebo-controlled and active comparator studies were 0.46 (0.25–0.83), P = .009, and 1.05 (0.63–1.76), P = .84, respectively. Conclusions. To date, results of randomized trials do not suggest any detrimental effect of GLP-1 receptor agonists on cardiovascular events. Specifically designed longer-term trials are needed to verify the possibility of a beneficial effect.