Lixisenatide as add-on to oral anti-diabetic therapy: an effective treatment for glycaemic control with body weight benefits in type 2 diabetes

PRISMA-efficacy and safety of lixisenatide for type 2 diabetes mellitus: A meta-analysis of randomized controlled trials

OBJECTIVE

We aimed to systematically evaluate the efficacy and safety of lixisenatide in patients with type 2 diabetes mellitus.

METHODS

PubMed, EMBASE, Cochrane Library, ClinicalTrials.gov, Google, Web of Science and the Chinese Science Citation Database were searched up to March 2018. Randomized controlled trials determining the efficacy and safety of lixisenatide in patients with type 2 diabetes mellitus were eligible for inclusion. Two authors independently extracted the data in a prespecified Microsoft Excel spreadsheet. A meta-analysis was performed using Review Manager 5.3 software. Weighted mean difference (WMD) and relative risk (RR) together with their corresponding 95% confidence intervals (CIs) were estimated, and only the random effects model was used in order to achieve a more conservative estimate of the efficacy and safety.

RESULTS

Fourteen multicenter randomized controlled trials involving 11,947 patients were eligible for inclusion. Compared to placebo, lixisenatide could more significantly reduce the level of HbA1c (WMD=-0.44; 95% confidence interval [CI] [-0.55,-0.33]), and a higher proportion of lixisenatide-treated patients achieved the HbA1c level of < 7.0% (RR = 1.89, 95% CI [1.75-2.03]) and < 6.5% (RR = 3.03, 95% CI [2.54-3.63]) than the placebo-treated patients. Lixisenatide was also associated with a significant reduction in fasting plasma glucose and 2-hour postprandial plasma glucose levels. The risks for any adverse events, gastrointestinal adverse events, and symptomatic hypoglycemia significantly increased in the lixisenatide-treatedment group compared to those in the placebo group. However, lixisenatideit did not increase the risks of serious adverse events, death, or severe hypoglycemia.

CONCLUSIONS

Lixisenatide was more effective than placebo in patients with type 2 diabetes mellitus, and the mild-to-moderate adverse events were found to be tolerated during the follow-up.

GLP-1 suppresses glucagon secretion in human pancreatic alpha-cells by inhibition of P/Q-type Ca2+ channels

Glucagon is the body's main hyperglycemic hormone, and its secretion is dysregulated in type 2 diabetes mellitus (T2DM). The incretin hormone glucagon-like peptide-1 (GLP-1) is released from the gut and is used in T2DM therapy. Uniquely, it both stimulates insulin and inhibits glucagon secretion and thereby lowers plasma glucose levels. In this study, we have investigated the action of GLP-1 on glucagon release from human pancreatic islets. Immunocytochemistry revealed that only <0.5% of the α-cells possess detectable GLP-1R immunoreactivity. Despite this, GLP-1 inhibited glucagon secretion by 50-70%. This was due to a direct effect on α-cells, rather than paracrine signaling, because the inhibition was not reversed by the insulin receptor antagonist S961 or the somatostatin receptor-2 antagonist CYN154806. The inhibitory effect of GLP-1 on glucagon secretion was prevented by the PKA-inhibitor Rp-cAMPS and mimicked by the adenylate cyclase activator forskolin. Electrophysiological measurements revealed that GLP-1 decreased action potential height and depolarized interspike membrane potential. Mathematical modeling suggests both effects could result from inhibition of P/Q-type Ca2+ channels. In agreement with this, GLP-1 and ω-agatoxin (a blocker of P/Q-type channels) inhibited glucagon secretion in islets depolarized by 70 mmol/L [K+ ]o , and these effects were not additive. Intracellular application of cAMP inhibited depolarization-evoked exocytosis in individual α-cells by a PKA-dependent (Rp-cAMPS-sensitive) mechanism. We propose that inhibition of glucagon secretion by GLP-1 involves activation of the few GLP-1 receptors present in the α-cell membrane. The resulting small elevation of cAMP leads to PKA-dependent inhibition of P/Q-type Ca2+ channels and suppression of glucagon exocytosis.

Glucagon-like peptide 1 in health and disease

In healthy individuals, the incretin hormone glucagon-like peptide 1 (GLP1) potentiates insulin release and suppresses glucagon secretion in response to the ingestion of nutrients. GLP1 also delays gastric emptying and increases satiety. In patients with type 2 diabetes mellitus (T2DM), supraphysiological doses of GLP1 normalize the endogenous insulin response during a hyperglycaemic clamp. Owing to the short plasma half-life of native GLP1, several GLP1 receptor agonists (GLP1RAs) with longer half-lives have been developed for the treatment of T2DM. These compounds vary in chemical structure, pharmacokinetics and size, which results in different clinical effects on hyperglycaemia and body weight loss; these variations might also explain the difference in cardiovascular effect observed in large-scale cardiovascular outcome trials, in which certain GLP1RAs were shown to have a positive effect on cardiovascular outcomes. Owing to their metabolic effects, GLP1RAs are also considered for the treatment of several other lifestyle-induced conditions, such as obesity, prediabetes and liver disease. This Review provides insights into the physiology of GLP1 and its involvement in the pathophysiology of T2DM and an overview of the currently available and emerging GLP1RAs. Furthermore, we review the results from the currently available large-scale cardiovascular outcome trials and the use of GLP1RAs for other indications.

Lixisenatide, a Once-Daily Prandial Glucagon-Like Peptide-1 Receptor Agonist for the Treatment of Adults with Type 2 Diabetes

Lixisenatide, a short-acting glucagon-like peptide-1 receptor agonist (GLP-1 RA), has been available in Europe since 2013 and was recently approved in the United States for the treatment of type 2 diabetes (T2D) as an adjunct to diet and exercise. The objective of this systematic review is to describe the pharmacology, pharmacokinetics, safety, and efficacy of lixisenatide in patients with T2D. We conducted a search of the EMBASE database, limited to human studies with abstracts available in English. Published conference abstracts, limited to the American Diabetes Association (ADA) and the European Association for the Study of Diabetes meetings in 2015, as well as abstracts presented at the ADA meeting in 2016, were also screened. The abstracts retrieved were assessed for relevance; review articles and meta-analyses focusing on GLP-1 RAs as a class were excluded. Lixisenatide induced mean reductions of 0.46-0.99% in glycated hemoglobin A_1c (Hb_A1c ), 55.86-143.43 mg/dl in 2-hour postprandial glucose (PPG) levels, and 56.58-127.75 mg/dl in mealtime glucose level variations. Changes in fasting plasma glucose (FPG) levels and weight ranged from -21.98 to +5.41 mg/dl and from -2.96 to +0.3 kg, respectively, in patients with T2D enrolled in the GetGoal clinical program (a program of clinical trials that established the efficacy and safety profile of lixisenatide 20 μg once/day across patients with T2D with differing background therapies). Lixisenatide was well tolerated, demonstrating rates of symptomatic hypoglycemia of 0.8-42.9% and a very low rate of severe hypoglycemia (< 1.5%) as well as no increased risk of cardiovascular events. The most common adverse events were gastrointestinal in nature, mainly transient nausea and vomiting of mild-to-moderate severity. Lixisenatide effectively lowers Hb_A1c levels in patients with T2D through a mechanism of action complementary to that of agents that mainly target FPG, with the additional benefit of weight loss. Its once-daily administration schedule and effect on PPG levels make it an attractive option as add-on treatment to basal insulin therapy or oral antidiabetic agents.

Beneficial effect of lixisenatide after 76 weeks of treatment in patients with type 2 diabetes mellitus: A meta-analysis from the GetGoal programme

AIMS

To evaluate the long-term efficacy and safety of lixisenatide, a short-acting, prandial glucagon-like peptide-1 receptor agonists (GLP-1 RA) as add-on therapy in type 2 diabetes mellitus.

METHODS

A meta-analysis of 76-week results of 5 placebo-controlled clinical trials from the GetGoal programme was performed, including 3000 inadequately controlled adult diabetic patients where lixisenatide 20 µg once-daily was administered in combination with metformin (GetGoal-M and GetGoal-F1), sulphonylurea ± metformin (GetGoal-S), basal insulin ± metformin (GetGoal-L) or pioglitazone ± metformin (GetGoal-P).

RESULTS

A significant reduction in HbA1c at 76 weeks was observed in the intervention arm compared to placebo (LSM difference: -0.41%, 95%CI: -0.51, -0.32, P < .00001). Compared to placebo, lixisenatide induced a larger decrease in fasting plasma glucose (LSM difference -0.49 mmol/L, 95% CI -0.71, -0.27, P < .0001) and postprandial glucose excursion after a standard test meal (LSM difference -3.29 mmol/L, 95% CI -4.17, -2.42, P < .00001). A bodyweight reduction was observed in the lixisenatide arm (LSM difference -0.40 kg, 95%CI: -0.8, -0.01, P = .05). The risk of hypoglycaemia was slightly higher with lixisenatide vs placebo (risk difference +0.02, 95% CI: 0, 0.04, P = .04). The most commonly observed non-severe adverse events were nausea and vomiting, which after week 16 and week 8, were steadily <4% and <1% in the lixisenatide arm, respectively.

CONCLUSIONS

Lixisenatide, a once-daily prandial GLP-1 RA, provides long-term glycaemic control, a sustained beneficial effect on weight and with a good safety profile.

Pharmacology and therapeutic implications of current drugs for type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a global epidemic that poses a major challenge to health-care systems. Improving metabolic control to approach normal glycaemia (where practical) greatly benefits long-term prognoses and justifies early, effective, sustained and safety-conscious intervention. Improvements in the understanding of the complex pathogenesis of T2DM have underpinned the development of glucose-lowering therapies with complementary mechanisms of action, which have expanded treatment options and facilitated individualized management strategies. Over the past decade, several new classes of glucose-lowering agents have been licensed, including glucagon-like peptide 1 receptor (GLP-1R) agonists, dipeptidyl peptidase 4 (DPP-4) inhibitors and sodium/glucose cotransporter 2 (SGLT2) inhibitors. These agents can be used individually or in combination with well-established treatments such as biguanides, sulfonylureas and thiazolidinediones. Although novel agents have potential advantages including low risk of hypoglycaemia and help with weight control, long-term safety has yet to be established. In this Review, we assess the pharmacokinetics, pharmacodynamics and safety profiles, including cardiovascular safety, of currently available therapies for management of hyperglycaemia in patients with T2DM within the context of disease pathogenesis and natural history. In addition, we briefly describe treatment algorithms for patients with T2DM and lessons from present therapies to inform the development of future therapies.

Once-Daily Liraglutide Versus Lixisenatide as Add-on to Metformin in Type 2 Diabetes: A 26-Week Randomized Controlled Clinical Trial

OBJECTIVE

To compare the efficacy and safety of liraglutide versus lixisenatide as add-on to metformin in patients with type 2 diabetes not achieving adequate glycemic control on metformin alone.

RESEARCH DESIGN AND METHODS

In this 26-week, randomized, parallel-group, open-label trial, 404 patients were randomized 1:1 to liraglutide 1.8 mg or lixisenatide 20 µg as add-on to metformin. Liraglutide was administered once daily at any time of the day. Lixisenatide was administered once daily within 1 h prior to the morning or evening meal.

RESULTS

At week 26, liraglutide reduced HbA1c (primary end point) more than lixisenatide (estimated treatment difference -0.62% [95% CI -0.8; -0.4]; P < 0.0001), with more patients reaching HbA1c <7% (53 mmol/mol) and ≤6.5% (48 mmol/mol) versus lixisenatide (74.2% and 54.6% for liraglutide vs. 45.5% and 26.2% for lixisenatide; P < 0.0001 for both). Liraglutide reduced fasting plasma glucose more than lixisenatide (estimated treatment difference -1.15 mmol/L [95% CI -1.5; -0.8]; P < 0.0001). Liraglutide provided greater reduction in mean 9-point self-measured plasma glucose (P < 0.0001). However, postprandial glucose increments were smaller with lixisenatide for the meal directly after injection compared with liraglutide (P < 0.05), with no differences between treatments across all meals. Both drugs promoted similar body weight decrease (-4.3 kg for liraglutide, -3.7 kg for lixisenatide; P = 0.23). The most common adverse events in both groups were gastrointestinal disorders. Greater increases in pulse, lipase, and amylase were observed with liraglutide. Hypoglycemic episodes were rare and similar between the two treatments.

CONCLUSIONS

At the dose levels studied, liraglutide was more effective than lixisenatide as add-on to metformin in improving glycemic control. Body weight reductions were similar. Both treatments were well tolerated, with low risk of hypoglycemia and similar gastrointestinal adverse event profiles.

Efficacy and safety of dulaglutide in patients with type 2 diabetes: a meta-analysis and systematic review

A meta-analysis was conducted to assess the clinical efficacy and safety of dulaglutide in patients with type 2 diabetes mellitus (T2DM). Medline, Embase, Cochrane Library and www. clinicaltrials. gov (up to February 15^th, 2015) were searched. Randomized controlled trials comparing dulaglutide to other drugs for T2DM were collected. Twelve RCTs were included, and the overall bias was low. As the monotherapy, compared with control (placebo, metformin and liraglutide), dulaglutide resulted in a significant reduction in HbA1c (WMD, −0.68%; 95% CI, −0.95 to −0.40), FPG (WMD, −0.90 mmol/L; 95% CI, −1.28 to −0.52), a similar risk of hypoglycemia (7.8% vs. 10.6%), less body weight loss (WMD, 0.51 kg; 95% CI, 0.27 to 0.75). As an add-on intervention with oral antihyperglycemic medication (OAM) and insulin, compared with control (placebo, sitagliptin, exenatide, liraglutide and glargine), dulaglutide lowered HbA1c (WMD, −0.51%; 95% CI, −0.68 to −0.35) and body weight significantly (WMD, −1.30 kg, 95% CI, −1.85 to −1.02) notably, and elicited a similar reduction in FPG (WMD, −0.19 mmol/L; 95% CI, −1.20 to 0.82), an similar incidence of hypoglycemia (24.5% vs. 24.5%). This meta-analysis revealed the use of dulaglutide as a monotherapy or an add-on to OAM and lispro appeared to be effective and safe for adults with T2DM.

Current and emerging medications for overweight or obesity in people with comorbidities

Recently, the recognition of obesity as a complex disease that requires chronic management has become more widespread. There has also been a movement away from a focus on body mass index alone, and toward the management of obesity-related comorbidities as well as excess weight. This article examines the current and emerging pharmacological options for weight management in people with overweight or obesity who have, or are at a high risk of, weight-related comorbidities. In the USA, the current options for pharmacological weight management are phentermine (indicated for short-term use only), orlistat, combined phentermine/topiramate extended release, lorcaserin, naltrexone/bupropion and liraglutide 3.0 mg. Currently, orlistat, naltrexone/bupropion and liraglutide 3.0 mg are approved in Europe. All of the above-mentioned medications have shown weight-loss efficacy versus placebo. Those approved for long-term weight management have also been associated with improvements in weight-related comorbidities, such as hypertension, prediabetes, diabetes or dyslipidaemia, or related biomarkers. As with all drugs, the safety and tolerability profiles of medications for weight management should be considered alongside their efficacy to ensure correct use. Additional medications for weight management that are in clinical development include bupropion/zonisamide and beloranib. The field of obesity treatment is advancing with a number of medications being recently approved, and with other pharmacological options emerging.

GLP-1 receptor agonists: Nonglycemic clinical effects in weight loss and beyond

OBJECTIVE

Glucagon-like peptide-1 (GLP-1) receptor agonists are indicated for treatment of type 2 diabetes since they mimic the actions of native GLP-1 on pancreatic islet cells, stimulating insulin release, while inhibiting glucagon release, in a glucose-dependent manner. The observation of weight loss has led to exploration of their potential as antiobesity agents, with liraglutide 3.0 mg day(-1) approved for weight management in the US on December 23, 2014, and in the EU on March 23, 2015. This review examines the potential nonglycemic effects of GLP-1 receptor agonists.

METHODS

A literature search was conducted to identify preclinical and clinical evidence on nonglycemic effects of GLP-1 receptor agonists.

RESULTS

GLP-1 receptors are distributed widely in a number of tissues in humans, and their effects are not limited to the well-recognized effects on glycemia. Nonglycemic effects include weight loss, which is perhaps the most widely recognized nonglycemic effect. In addition, effects on the cardiovascular, neurologic, and renal systems and on taste perception may occur independently of weight loss.

CONCLUSIONS

GLP-1 receptor agonists may provide other nonglycemic clinical effects besides weight loss. Understanding these effects is important for prescribers in using GLP-1 receptor agonists for diabetic patients, but also if approved for chronic weight management.

Glucagon-like peptide-1 receptor agonist therapeutics for total diabetes management: assessment of composite end-points

Assessment of the benefits of anti-diabetic drugs for type 2 diabetes requires analysis of composite end-points, taking HbA1c, bodyweight, hypoglycemia and other metabolic parameters into consideration; continuous, optimal glycemic control as well as bodyweight, blood pressure and lipid levels are critical to prevent micro- and macro-vascular complications. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are now established as an important total treatment strategy for type 2 diabetes, exerting glucose-lowering effects with little hypoglycemia risk and also ameliorating bodyweight, blood pressure and lipid levels, which are therapeutic targets for prevention of complications of the disease. The available data strongly suggest only beneficial effects of GLP-1RAs; however, long-term evaluation of the relevant composite end-points including health-related quality of life and cost-effectiveness remain to be investigated in adequately powered, prospective, controlled clinical trials. In the meantime, healthcare professionals need to be scrupulously attentive for potential, rare adverse events in patients using GLP-1RAs.