Glucagon-like peptide-1 receptor agonists in type 2 diabetes treatment: are they all the same?

Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are an important class of drugs with a well-established efficacy and safety profile in patients with type 2 diabetes mellitus. Agents in this class are derived from either exendin-4 (a compound present in Gila monster venom) or modifications of human GLP-1 active fragment. Differences among these drugs in duration of action (ie, short-acting vs long-acting), effects on glycaemic control and weight loss, immunogenicity, tolerability profiles, and administration routes offer physicians several options when selecting the most appropriate agent for individual patients. Patient preference is also an important consideration. The aim of this review is to discuss the differences between and similarities of GLP-1 RAs currently approved for clinical use, focusing particularly on the properties characterising the single short-acting and long-acting GLP-1 RAs rather than on their individual efficacy and safety profiles. The primary pharmacodynamic difference between short-acting (ie, exenatide twice daily and lixisenatide) and long-acting (ie, albiglutide, dulaglutide, exenatide once weekly, liraglutide, and semaglutide) GLP-1 RAs is that short-acting agents primarily delay gastric emptying (lowering postprandial glucose) and long-acting agents affect both fasting glucose (via enhanced glucose-dependent insulin secretion and reduced glucagon secretion in the fasting state) and postprandial glucose (via enhanced postprandial insulin secretion and inhibition of glucagon secretion). Other advantages of long-acting GLP-1 RAs include smaller fluctuations in plasma drug concentrations, improved gastrointestinal tolerability profiles, and simpler, more convenient administration schedules (once daily for liraglutide and once weekly for albiglutide, dulaglutide, the long-acting exenatide formulation, and semaglutide), which might improve treatment adherence and persistence.

Adherence to antihyperglycemic medications and glucagon-like peptide 1-receptor agonists in type 2 diabetes: clinical consequences and strategies for improvement.

Adherence to antihyperglycemic medications is often suboptimal in patients with type 2 diabetes, and this can contribute to poor glycemic control, increased hospitalization, and the development of diabetic complications. Reported adherence rates to antihyperglycemics vary widely among studies, and this may be related to differences in methodology for measuring adherence, patient populations, and other factors. Poor adherence may occur regardless of the specific regimen used and whether therapy is oral or injectable, and can be especially common in chronic, asymptomatic conditions, such as type 2 diabetes. More convenient drug-administration regimens and advances in formulations and delivery devices are among strategies shown to improve adherence to antihyperglycemic therapy, especially for injectable therapy. This is exemplified by technological developments made in the drug class of glucagon-like peptide 1-receptor agonists, which are a focus of this narrative review. Dulaglutide, albiglutide, and prolonged-release exenatide have an extended duration of action and can be administered once weekly, whereas such agents as liraglutide require once-daily administration. The convenience of once-weekly versus once-daily administration is associated with better adherence in real-world studies involving this class of agent. Moreover, provision of a user-friendly delivery device has been shown to overcome initial resistance to injectable therapy among patients with type 2 diabetes. This suggests that recent innovations in drug formulation (eg, ready-to-use formulations) and delivery systems (eg, single-dose prefilled pens and hidden, ready-attached needles) may be instrumental in encouraging patient acceptance. For physicians who aim to improve their patients' adherence to antihyperglycemic medications, it is thus important to consider the patient's therapeutic experience (treatment frequency, drug formulation, delivery device). Better adherence, powered by recent technological advances in the delivery of glucagon-like peptide 1-receptor agonists, may thus lead to improved clinical outcomes in type 2 diabetes.

Efficacy and Safety of Once-Weekly Dulaglutide Versus Insulin Glargine in Patients With Type 2 Diabetes on Metformin and Glimepiride (AWARD-2).

OBJECTIVE: This study compared the efficacy and safety of once-weekly dulaglutide, a glucagon-like peptide-1 receptor agonist, with daily insulin glargine, both combined with maximally tolerated doses of metformin and glimepiride in patients with type 2 diabetes. The primary objective was noninferiority of dulaglutide 1.5 mg to glargine in the HbA1c change from baseline at 52 weeks. RESEARCH DESIGN AND METHODS: In this 78-week, open-label study, 810 patients were randomized to dulaglutide 1.5 mg, dulaglutide 0.75 mg, or glargine. RESULTS: The baseline mean ± SD HbA1c was 8.1 ± 1.0% (65.5 ± 10.8 mmol/mol). The least squares mean ± SE HbA1c change from baseline to the primary end point was -1.08 ± 0.06% (-11.8 ± 0.7 mmol/mol) for dulaglutide 1.5 mg, -0.76 ± 0.06% (-8.3 ± 0.7 mmol/mol) for dulaglutide 0.75 mg, and -0.63 ± 0.06% (-6.9 ± 0.7 mmol/mol) for glargine, with an end point mean ± SD dose of 29 ± 26 units (0.33 ± 0.24 units/kg), and a fasting plasma glucose (mean ± SD) of 118 ± 23 mg/dL from self-monitored plasma glucose. Statistical criteria for superiority were met with dulaglutide 1.5 mg and for noninferiority with dulaglutide 0.75 mg. More patients on dulaglutide 1.5 mg achieved HbA1c targets <7.0% (53 mmol/mol) versus glargine (P < 0.001). Body weight decreased with dulaglutide and increased with glargine. Total hypoglycemia rates were lower with dulaglutide; severe hypoglycemia was minimal. Increases in pancreatic enzymes were observed for dulaglutide. Incidence of nausea (15.4, 7.7, and 1.5%) and diarrhea (10.6, 9.2, and 5.7%) were more common with dulaglutide 1.5 mg and 0.75 mg than with glargine. CONCLUSIONS: Once-weekly dulaglutide 1.5 mg, compared with daily insulin glargine without forced titration, demonstrated greater HbA1c reduction and weight loss, with a higher incidence of gastrointestinal adverse events and a lower risk of hypoglycemia.

Efficacy and safety of dulaglutide monotherapy versus metformin in type 2 diabetes in a randomized controlled trial (AWARD-3).

OBJECTIVE: Compare the efficacy and safety of monotherapy with dulaglutide, a once-weekly GLP-1 receptor agonist, to metformin-treated patients with type 2 diabetes. The primary objective compared dulaglutide 1.5 mg and metformin on change from baseline glycosylated hemoglobin A1c (HbA1c) at 26 weeks. RESEARCH DESIGN AND METHODS: This 52-week double-blind study randomized patients to subcutaneous dulaglutide 1.5 mg, dulaglutide 0.75 mg, or metformin. Patients (N = 807) had HbA1c ≥6.5% (≥48 mmol/mol) and ≤9.5% (≤80 mmol/mol) with diet and exercise alone or low-dose oral antihyperglycemic medication (OAM) monotherapy; OAMs were discontinued at beginning of lead-in period. RESULTS: At 26 weeks, changes from baseline HbA1c (least squares [LS] mean ± SE) were: dulaglutide 1.5 mg, -0.78 ± 0.06% (-8.5 ± 0.70 mmol/mol); dulaglutide 0.75 mg, -0.71 ± 0.06% (-7.8 ± 0.70 mmol/mol); and metformin, -0.56 ± 0.06% (-6.1 ± 0.70 mmol/mol). Dulaglutide 1.5 and 0.75 mg were superior to metformin (LS mean difference): -0.22% (-2.4 mmol/mol) and -0.15% (-1.6 mmol/mol) (one-sided P < 0.025, both comparisons), respectively. Greater percentages reached HbA1c targets <7.0% (<53 mmol/mol) and ≤6.5% (≤48 mmol/mol) with dulaglutide 1.5 and 0.75 mg compared with metformin (P < 0.05, all comparisons). No severe hypoglycemia was reported. Compared with metformin, decrease in weight was similar with dulaglutide 1.5 mg and smaller with dulaglutide 0.75 mg. Over 52 weeks, nausea, diarrhea, and vomiting were the most common adverse events; incidences were similar between dulaglutide and metformin. CONCLUSIONS: Dulaglutide improves glycemic control and is well tolerated as monotherapy in patients with early stage type 2 diabetes.

Treatment for 2 mo with n 3 polyunsaturated fatty acids reduces adiposity and some atherogenic factors but does not improve insulin sensitivity in women with type 2 diabetes: a randomized controlled study.

BACKGROUND: Information is lacking on the potential effect of n-3 polyunsaturated fatty acids (PUFAs) on the adipose tissue of patients with type 2 diabetes. OBJECTIVE: We evaluated whether n-3 PUFAs have additional effects on adiposity, insulin sensitivity, adipose tissue function (production of adipokines and inflammatory and atherogenic factors), and gene expression in type 2 diabetes. DESIGN: Twenty-seven women with type 2 diabetes without hypertriglyceridemia were randomly allocated in a double-blind parallel design to 2 mo of 3 g/d of either fish oil (1.8 g n-3 PUFAs) or placebo (paraffin oil). RESULTS: Although body weight and energy intake measured by use of a food diary were unchanged, total fat mass (P < 0.019) and subcutaneous adipocyte diameter (P < 0.0018) were lower in the fish oil group than in the placebo group. Insulin sensitivity was not significantly different between the 2 groups (measured by homeostasis model assessment in all patients and by euglycemic-hyperinsulinemic clamp in a subgroup of 5 patients per group). By contrast, atherogenic risk factors, including plasma triacylglycerol (P < 0.03), the ratio of triacylglycerol to HDL cholesterol (atherogenic index, P < 0.03), and plasma plasminogen activator inhibitor-1 (P < 0.01), were lower in the fish oil group than in the placebo group. In addition, a subset of inflammation-related genes was reduced in subcutaneous adipose tissue after the fish oil, but not the placebo, treatment. CONCLUSIONS: A moderate dose of n-3 PUFAs for 2 mo reduced adiposity and atherogenic markers without deterioration of insulin sensitivity in subjects with type 2 diabetes. Some adipose tissue inflammation-related genes were also reduced. These beneficial effects could be linked to morphologic and inflammatory changes in adipose tissue. This trial was registered at clinicaltrials.gov as NCT0037.