Translating science into clinical practice: focus on vildagliptin in combination with metformin

Vildagliptin is a potent and selective oral dipeptidyl peptidase‐4 inhibitor that improves glycaemic control in patients with type 2 diabetes mellitus (T2DM) by increasing both α‐ and β‐cell responsiveness to glucose. The efficacy, tolerability and safety of the combination of vildagliptin and metformin in the treatment of T2DM have been established in numerous trials in the extensive vildagliptin clinical programme. As add‐on therapy in patients with inadequate glycaemic control on metformin, vildagliptin produces clinically significant reductions in glycated haemoglobin (HbA1c) and fasting plasma glucose, is well tolerated, and is associated with absence of weight gain and minimal risk of hypoglycaemia. Compared with thiazolidinedione add‐on treatment, vildagliptin is associated with similar significant reductions in HbA1c without the weight gain seen with the former. Compared with sulfonylurea add‐on treatment, vildagliptin is associated with similar efficacy in controlling glycaemia but absence of weight gain and a markedly lower risk of hypoglycaemia. In drug‐naïve patients, single‐tablet combinations of vildagliptin/metformin 50/500 and 50/1000 mg bid produced significantly greater reductions in HbA1c than monotherapy with either agent and were well tolerated, with no weight gain and minimal risk of hypoglycaemia. The combination of vildagliptin and metformin poses numerous advantages in the treatment of T2DM.     

The DPP-4 inhibitor vildagliptin: robust glycaemic control in type 2 diabetes and beyond

Vildagliptin is a potent selective inhibitor of dipeptidyl peptidase-4 (DPP-4) that improves glycaemic control by increasing islet α-cell and β-cell responsiveness to glucose. In patients with type 2 diabetes mellitus (T2DM), vildagliptin improves β-cell function, measured as insulin secretory rate relative to glucose level, and reduces glucagon secretion and endogenous glucose production in the postprandial period, resulting in reduced glucose levels. In clinical trials in T2DM, vildagliptin 100 mg/day monotherapy is effective in reducing haemoglobin A1c (HbA1c) across the spectrum of hyperglycaemia and has maintained efficacy over long-term treatment with neutral effects on body weight and lipids. Vildagliptin is associated with a low risk of hypoglycaemia, and has an adverse event profile comparable to placebo, including a reduced rate of gastrointestinal adverse effects compared with metformin and a reduced rate of oedema compared with rosiglitazone. As add-on combination therapy, vildagliptin produces significant further reductions in HbA1c in patients receiving metformin, pioglitazone, glimepiride and insulin, and has been found to reduce frequency of hypoglycaemia as an add-on to insulin. Preliminary findings indicate that the improved islet cell function underlying the efficacy of vildagliptin in T2DM is also observed in patients with impaired glucose tolerance, with vildagliptin treatment resulting in reduced glycaemic excursions. The overall profile of vildagliptin and the preliminary evidence of beneficial effects in the prediabetic state suggest that DPP-4 inhibition could be an effective strategy to prevent or delay progression from the prediabetic state to overt T2DM.     

Metformin – the gold standard in type 2 diabetes: what does the evidence tell us?

Metformin is a cornerstone of oral antidiabetic treatment. Recent joint American and European guidelines recommend instituting metformin therapy along with lifestyle modification at the time type 2 diabetes mellitus (T2DM) is diagnosed. Metformin acts to reduce hepatic gluconeogenesis and improve glucose uptake, and it may exert protective effects on pancreatic islet cells. Although metformin therapy produces substantial reductions in HbA1c, it does not produce body weight gain, is not associated with substantial risk for hypoglycaemia and has neutral to positive effects on lipids and blood pressure. The major adverse events associated with metformin are gastrointestinal. T2DM progresses even with initially effective monotherapy, and most patients will therefore receive combination therapy. When selecting agents to coadminister with metformin, a physician must consider efficacy in glycaemic control, safety, tolerability and any effects that may compromise overall efficacy (e.g. effects on body weight, lipids or blood pressure). In this regard, incretin-based therapies have characteristics that make them particularly suitable for add-on therapy with metformin.     

Therapeutic approach of type 2 diabetes mellitus with GLP-1 based therapies

The goal of this review is to think about how to incorporate the GLP-1 based agents, represented by the dipeptidyl peptidase-4 (DPP-4) inhibitors or the glucagon-like peptide-1 (GLP-1) analogs, in the guidelines for the management of type 2 diabetes (T2DM). Orally administered DPP-4 inhibitors, such as sitagliptin and vildagliptin, reduce HbA(1c) (absolute values) by 0.5-1.1% (5 to 12%, relative values), with few adverse events and no weight gain. The sub-cutaneous injected GLP-1 analogs show larger reductions in HbA(1c) (0.8-1.7%, absolute values; 9.4-20.0%, relative values), associated with weight loss (1.75-3.8 kg); their most common adverse events are gastrointestinal symptoms which contribute to a substantial treatment interruption. If they do not challenge the use of metformin as the initial therapy of T2DM, several studies argue in favour of the use of DPP-4 inhibitors, either in combination with metformin as the initial treatment or, in add-on therapy to metformin. The advantages of this combination over others currently used are reviewed. In patients not tolerating metformin, DPP-4 inhibitors seem to be an excellent alternative as a monotherapy. As long as oral triple therapy is concerned, the choice for the association metformin + thiazolidinedione + incretin-based drug, has again several theoretical advantages against other triple therapy combinations. Finally, in patients with T2DM inadequately controlled with maximal tolerated oral multi-therapies, GLP-1 agonists are a good alternative to insulin therapy, allowing reaching a better glycaemic control together with a weight loss. However, for patients who do not tolerate GLP-1 agonist treatment, and for those not reaching the HbA(1c) target, insulin will remain necessary, allowing getting a better metabolic control, with few adverse events. The long-term effect of these new agents on glycaemic control has not yet been established, and their potential impact on beta-cell function in humans remains an area of active investigation. So, further studies are needed and will allow progressively refining the use of incretin-based agents in T2DM treatment strategy.     

Continuing metformin when starting insulin in patients with Type 2 diabetes: a double-blind randomized placebo-controlled trial.

AIMS: To test the effect of continuing metformin on weight gain and glycaemic control in patients with poorly controlled Type 2 diabetes who need to start insulin. METHODS: Patients with Type 2 diabetes on maximum tolerated oral agents referred for insulin conversion were recruited from hospital diabetes clinics into a double-blind randomized placebo-controlled trial. The 183 participants received metformin or placebo, titrated up to 2 g a day or maximum tolerated dose, with insulin started according to local practice. The main outcome measures were weight change over 12 months, HbA1c, insulin dose, frequency of hypoglycaemia, treatment satisfaction, and well-being. RESULTS: Over 12 months, metformin was associated with less weight gain than placebo [mean 6.1 kg vs. 7.6 kg; adjusted difference 1.5 kg (95% confidence interval 0.2-2.9); P=0.02], a greater reduction in HbA1c[1.5% vs. 1.3%; adjusted difference 0.5% (0.1-0.9); P=0.02] and a lower insulin requirement [62 units vs. 86; adjusted difference 25 units (15-34); P<0.001], but also more hypoglycaemia [relative risk of any episode 1.24 (1.02-1.1); P=0.03]. Treatment satisfaction improved more in patients on metformin than on placebo (P<0.001), as did the positive well-being score (P=0.02). CONCLUSIONS: Metformin decreases weight gain, lowers insulin requirement, and improves glycaemic control, and should be continued in patients with Type 2 diabetes who transfer to insulin.     

Targeting hyperglycaemia with either metformin or repaglinide in non-obese patients with type 2 diabetes: results from a randomized crossover trial

AIM: Metformin is the 'drug-of-first-choice' in obese patients with type 2 diabetes mellitus (T2DM) due to its antihyperglycaemic and cardiovascular protective potentials. In non-obese patients with T2DM, insulin secretagogues are empirically used as first choice. In this investigator-initiated trial, we evaluated the effect of metformin vs. an insulin secretagogue, repaglinide on glycaemic regulation and markers of inflammation and insulin sensitivity in non-obese patients with T2DM. METHODS: A single-centre, double-masked, double-dummy, crossover study during 2 x 4 months involved 96 non-obese (body mass index < or = 27 kg/m(2)) insulin-na?ve patients with T2DM. At enrolment, previous oral hypoglycaemic agents (OHA) were stopped and patients entered a 1-month run-in on diet-only treatment. Hereafter, patients were randomized to either repaglinide 2 mg thrice daily followed by metformin 1 g twice daily or vice versa each during 4 months with 1-month washout between interventions. RESULTS: End-of-treatment levels of haemoglobin A(1c) (HbA(1c)), fasting plasma glucose, mean of seven-point home-monitored plasma glucose and fasting levels of high-sensitivity C-reactive protein and adiponectin were not significantly different between treatments. However, body weight, waist circumference, fasting serum levels of insulin and C-peptide were lower and less number of patients experienced hypoglycaemia during treatment with metformin vs. repaglinide. Both drugs were well tolerated. CONCLUSIONS: In non-obese patients with T2DM, overall glycaemic regulation was equivalent with less hypoglycaemia during metformin vs. repaglinide treatment for 2 x 4 months. Metformin was more effective targeting non-glycaemic cardiovascular risk markers related to total and abdominal body fat stores as well as fasting insulinaemia. These findings may suggest the use of metformin as the preferred OHA also in non-obese patients with T2DM.     

Vildagliptin add‐on to metformin produces similar efficacy and reduced hypoglycaemic risk compared with glimepiride,with no weight gain: results from a 2‐year study

Aim: To show that vildagliptin added to metformin is non‐inferior to glimepiride in reducing HbA1c levels from baseline over 2 years. Methods: A randomized, double‐blind, active‐comparator study of patients with type 2 diabetes mellitus inadequately controlled (HbA1c 6.5–8.5%) by metformin monotherapy. Patients received vildagliptin (50 mg twice daily) or glimepiride (up to 6 mg/day) added to metformin. Results: In all, 3118 patients were randomized (vildagliptin, n = 1562; glimepiride, n = 1556). From similar baseline values (7.3%), after 2 years adjusted mean (s.e.) change in HbA1c was comparable between vildagliptin and glimepiride treatment: ?0.1% (0.0%) and ?0.1% (0.0%), respectively. The primary objective of non‐inferiority was met. A similar proportion of patients reached HbA1c <7% (36.9 and 38.3%, respectively), but with vildagliptin more patients reached this target without hypoglycaemia (36.0% vs. 28.8%; p = 0.004). The initial response (IR) was sustained for a mean (s.d.) of 309 (244) days with vildagliptin versus 270 (223) days for glimepiride (p < 0.001) (IR = nadir HbA1c where change from baseline ≥0.5% or HbA1c ≤6.5% within the first six months of treatment. After IR was detected, sustained response = time between nadir and an increase of >0.3% above IR). Independent of disease duration, age was a predictor of effect sustainability. Fewer patients experienced hypoglycaemia with vildagliptin (2.3% vs. 18.2% with glimepiride) with a 14‐fold difference in the number of hypoglycaemic events (59 vs. 838). Vildagliptin had a beneficial effect on body weight [mean (s.e.) change from baseline ?0.3 (0.1) kg; between‐group difference ?1.5 kg; p < 0.001]. Overall, both treatments were well tolerated and displayed similar safety profiles. Conclusions: Vildagliptin add‐on has similar efficacy to glimepiride after 2 years' treatment, with markedly reduced hypoglycaemia risk and no weight gain.     

Vildagliptin plus metformin combination therapy provides superior glycaemic control to individual monotherapy in treatment-naive patients with type 2 diabetes mellitus

Aim: To compare the efficacy and safety of vildagliptin and metformin initial combination therapy with individual monotherapies in treatment‐naive patients with type 2 diabetes mellitus (T2DM). Methods: This was a 24‐week, randomized, double‐blind, active‐controlled study. Treatment‐naive patients with T2DM who had a glycated haemoglobin (HbA_1c) of 7.5–11% (N = 1179) were randomized equally to receive vildagliptin plus high‐dose metformin combination therapy (50 mg + 1000 mg twice daily), vildagliptin plus low‐dose metformin combination therapy (50 mg + 500 mg twice daily), vildagliptin monotherapy (50 mg twice daily) or high‐dose metformin monotherapy (1000 mg twice daily). The primary objective was to demonstrate that HbA_1c reduction from baseline with either combination therapy is superior to both monotherapies at the week 24 endpoint. Patients who failed glycaemic‐screening criteria [HbA_1c >11% or fasting plasma glucose (FPG) >15 mmol/l (270 mg/dl)] could enter a 24‐week, single‐arm substudy. These patients (N = 94) received open‐label vildagliptin plus high‐dose metformin combination therapy (100 mg + 1000 mg twice daily). Results: From comparable baseline values (8.6–8.7%), HbA_1c decreased in all four treatment groups, to the greatest extent with vildagliptin plus high‐dose metformin combination therapy. Mean (SE) HbA_1c change from baseline was ?1.8% (0.06%), ?1.6% (0.06%), ?1.1% (0.06%) and ?1.4% (0.06%) with vildagliptin plus high‐dose metformin combination therapy, vildagliptin plus low‐dose metformin combination therapy, and vildagliptin and metformin monotherapies respectively. The between‐group difference was superior with vildagliptin plus high‐dose metformin combination therapy (p < 0.001 vs. both monotherapies) and vildagliptin plus low‐dose metformin combination therapy (p < 0.001 and p = 0.004, vs. vildagliptin and metformin monotherapies, respectively). Higher baseline HbA_1c values were linked to greater HbA_1c reductions, with changes of ?3.2% (0.22%), ?2.7% (0.22%), ?1.5% (0.24%) and ?2.6% (0.26%) respectively, occurring in patients with baseline HbA_1c≥10%. Reductions in FPG were superior with vildagliptin plus high‐dose metformin combination therapy [change from baseline ?2.63 (0.13) mmol/l] compared with both monotherapies [?1.26 (0.13) mmol/l and ?1.92 (0.13) mmol/l, respectively; p < 0.001]. There was no incidence of hypoglycaemia or severe hypoglycaemia with either combination therapy, and neither was associated with weight gain. All treatments were well tolerated and displayed a comparable incidence of adverse events overall. Despite superior HbA_1c lowering, the vildagliptin plus low‐dose metformin combination therapy group demonstrated a favourable gastrointestinal (GI) tolerability profile compared with metformin monotherapy. Conclusions: In treatment‐naive patients, combinations of vildagliptin and both high‐dose and low‐dose metformin provide superior efficacy to monotherapy treatments with a comparable overall tolerability profile and low risk of hypoglycaemia. The potential dose‐sparing effect of adding vildagliptin to low‐dose metformin in preference to the up‐titration of metformin may allow patients to achieve equivalent or superior HbA_1c lowering without the GI tolerability issues associated with higher doses of metformin.     

Efficacy and safety of linagliptin as add-on therapy to insulin in Chinese patients with type 2 diabetes mellitus: A randomized,double-blind,placebo-controlled trial

This 24-week, double-blind, placebo-controlled, phase III trial evaluated the efficacy and safety of linagliptin in 206 Chinese patients with inadequately controlled (glycated haemoglobin [HbA1c] 7.5%–10.0%) type 2 diabetes mellitus (T2DM) receiving insulin (basal or premixed) ± metformin. Patients were randomized (1:1) to receive linagliptin 5 mg/d or placebo. The decrease from baseline in HbA1c (primary endpoint) was greater with linagliptin than with placebo (−0.61% vs. −0.20%, adjusted mean difference −0.40%; P = 0.0016). Linagliptin demonstrated significantly greater improvement in 2-hour postprandial glucose (−1.77 mmol/L [−31.95 mg/dL]; P < 0.001), and a numerical reduction in fasting plasma glucose (−0.34 mmol/L [−6.2 mg/dL]; P = 0.2241) versus placebo. Proportionally more patients on linagliptin achieved a HbA1c reduction of ≥0.5% versus those on placebo (odds ratio 2.293, P < 0.01). Adverse events in both groups were similar, with no new safety findings or clinically relevant changes in body weight. Among investigator-defined hypoglycaemic events (linagliptin: 17.3%; placebo: 12.7%; odds ratio 1.48, P = 0.337), none were severe. In Chinese patients with T2DM, linagliptin add-on to insulin improved glycaemic control and was well tolerated, without increased risk of hypoglycaemia or weight gain.     

Glucagon-like peptide-1 receptor agonists or sodium–glucose cotransporter-2 inhibitors as add-on therapy for patients with type 2 diabetes? A systematic review and meta-analysis of surrogate metabolic endpoints

ObjectiveAs sodium–glucose cotransporter-2 inhibitors (SGLT-2is) and glucagon-like peptide-1 receptor agonists (GLP-1RAs) are second-line treatment options in type 2 diabetes mellitus (T2DM), our study sought to provide precise effect estimates regarding the role of GLP-1RAs vs SGLT-2is as add-on treatments in patients uncontrolled by metformin monotherapy.Research design and methodsPubMed, the Cochrane Central Register of Controlled Trials (CENTRAL) and ‘grey literature’ were searched from their inception up to December 2019 for randomized controlled trials (RCTs) with durations ≥ 12 weeks to evaluate the safety and efficacy of adding a GLP-1RA vs an SGLT-2i in patients with T2DM.ResultsThree eligible RCTs were identified. Administration of GLP-1RAs vs SGLT-2is resulted in significant decreases in HbA1c with no significant impact on either body weight or fasting plasma glucose. GLP-1RA treatment led to a significant increase in odds for achieving an HbA1c < 7% compared with SGLT-2is, whereas no difference was detected in body weight reductions of > 5%. Significantly greater risk for any hypoglycaemia, nausea and diarrhoea, and lower risk for genital infections, was also observed with GLP-1RAs, while no differences regarding severe hypoglycaemia, treatment discontinuation and impact on blood pressure levels were identified. No other major safety issues arose.ConclusionOur meta-analysis suggests that GLP-1RAs provide better glycaemic effects than SGLT-2is in patients with T2DM uncontrolled by metformin, albeit while increasing risk for hypoglycaemia and gastrointestinal adverse events.     

Comparison of alogliptin and glipizide for composite endpoint of glycated haemoglobin reduction,no hypoglycaemia and no weight gain in type 2 diabetes mellitus

This was a post hoc analysis of a 2‐year, double‐blind study of 2639 patients with type 2 diabetes mellitus (T2DM) inadequately controlled on metformin monotherapy, which assessed achievement of a composite endpoint of sustained glycated haemoglobin (HbA1c) reduction (≤7.0% at week 104 or ≥0.5% decrease from baseline) with no weight gain and no hypoglycaemic events with alogliptin 12.5 and 25 mg daily or glipizide (≤20 mg daily), each added to metformin. With an HbA1c target of ≤7.0%, 24.2 and 26.9% of patients treated with alogliptin 12.5 and 25 mg, respectively, achieved the composite endpoint versus 10.7% of patients treated with glipizide (both p < 0.001). With a criterion of ≥0.5% decrease in HbA1c, the composite endpoint was reached in 22.5, 25.2 and 10.4% of patients treated with alogliptin 12.5 mg, alogliptin 25 mg and glipizide, respectively. Odds ratios for achieving the composite endpoint favoured alogliptin in the primary analysis set and in all subgroups of patients. Patients with T2DM failing metformin monotherapy were more likely to achieve sustained glycaemic control with no hypoglycaemia or weight gain at 2 years with alogliptin than with glipizide.     

Efficacy and tolerability of vildagliptin as add-on therapy to metformin in Chinese patients with type 2 diabetes mellitus

Aim: To investigate the efficacy and tolerability of vildagliptin as add‐on therapy to metformin in Chinese patients with type 2 diabetes mellitus (T2DM) inadequately controlled with metformin. Methods: This was a 24‐week, randomized, double‐blind, placebo‐controlled study. Patients with T2DM (N = 438) with haemoglobin A1c (HbA1c) of 7.0–10.0% and fasting plasma glucose (FPG) <15 mmol/l (<270 mg/dl) were randomized (1 : 1 : 1) to vildagliptin 50 mg bid, vildagliptin 50 mg qd or placebo in addition to metformin. Results: The treatment groups were well balanced at baseline [mean HbA1c, 8.0%, FPG, 8.8 mmol/l (158 mg/dl); body mass index, 25.5 kg/m²]. The adjusted mean change (AMΔ) in HbA1c at endpoint was ?1.05 ± 0.08%, ?0.92 ± 0.08% and ?0.54 ± 0.08% in patients receiving vildagliptin 50 mg bid, 50 mg qd and placebo, respectively. The between‐treatment difference (vildagliptin 50 mg bid–placebo) was ?0.51 ± 0.11%, p < 0.001. A greater proportion of vildagliptin‐treated patients met at least one responder criterion (82.1 and 70.7%) compared to placebo‐treated patients (60.4%). The AMΔ at endpoint for FPG with vildagliptin 50 mg bid, ?0.95 mmol/l (?17.1 mg/dl); 50 mg qd, ?0.84 mmol/l (?15.1 mg/dl) was significantly different compared with the placebo ?0.26 mmol/l (?4.68 mg/dl) (p ≤ 0.001). Adverse events (AEs) were reported as 34.2, 36.5 and 37.5% for patients receiving vildagliptin 50 mg bid, 50 mg qd or placebo, respectively. Two patients in the vildagliptin 50 mg qd and one in the placebo group reported serious AEs, which were not considered to be related to the study drug; one incidence of hypoglycaemic event was reported in the vildagliptin 50 mg bid group. Conclusion: Vildagliptin as add‐on therapy to metformin improved glycaemic control and was well tolerated in Chinese patients who were inadequately controlled by metformin only.     

A randomized controlled trial examining combinations of repaglinide, metformin and NPH insulin.

AIMS: To compare combination use of repaglinide, metformin and bedtime Neutral Protamine Hagedorn (NPH) insulin with conventional approaches of insulin initiation in patients with Type 2 diabetes (T2DM). METHODS: Eighty-two patients with T2DM with suboptimal glycaemic control on oral glucose-lowering agents were randomized to one of three treatment regimens for 4 months. Group 1 received metformin and twice daily biphasic 30/70 human insulin mixture (n = 27), group 2 metformin and bedtime NPH insulin (n = 26) and group 3 metformin, bedtime NPH insulin and mealtime repaglinide (n = 25). RESULTS: Seventy-five patients completed the study. Baseline and end-point mean HbA1c levels fell from 9.0 +/- 1.1 to 7.9 +/- 1.1% in group 1, 10.0 +/- 2.2 to 9.2 +/- 1.4% group 2 and 10.0 +/- 1.7 to 8.1 +/- 1.5% in group 3, respectively. All groups showed improvements in HbA1c. There was no significant difference between groups in the proportions of patients experiencing hypoglycaemia (29.6, 25.0 and 16.7%, respectively; P = 0.55) or in mean weight gain (2.9, 0.7 and 2.2 kg, respectively; P = 0.06). By 4 months, insulin doses were 0.63 +/- 0.32 IU/kg in group 1, 0.58 +/- 0.21 IU/kg in group 2 and 0.37 +/- 0.22 IU/kg in group 3 (group 3 vs. groups 1 and 2: P < 0.002). CONCLUSIONS: The approach using repaglinide, metformin and NPH insulin improved glycaemic control with a similar safety profile to conventional insulin initiation in T2DM and produced final glycaemic control similar to metformin and a twice daily biphasic insulin mixture.     

DPP-4 inhibitors and GLP-1 analogues: for whom? Which place for incretins in the management of type 2 diabetic patients?

This review tries to delineate how to insert the GLP-1 based agents, DPP4-inhibitors (sitagliptin and vildagliptin) and GLP-1 analogues (exenatide and liraglutide), in the guidelines and the daily practice for the management of type 2 diabetes (T2DM). Orally administered DPP-4 inhibitors reduce HbA(1c) by 0.5-1.1%, without hypoglycaemic events and no weight gain. The subcutaneous injected GLP-1 analogues show larger reductions in HbA(1c) by 0.8-1.7% and a weight loss (1.75-3.8 kg) with most gastrointestinal common adverse events contributing to a significant treatment interruption. Regarding the efficacy, the cost and the safety of these drugs they will no challenge the use of metformin as the initial therapy of T2DM. In patients'not tolerating metformin or in older patients, DPP-4 inhibitors seem to be an excellent alternative monotherapy. Several studies argue in favour of the use of DPP-4 inhibitors in combination with metformin as a promising second line treatment. This combination offers advantages when compared to others currently used, particularly if one considers the more stringent guidelines with a higher risk of hypoglycaemic events in patient receiving sulfonylureas and mild hyperglycaemia or weight gain with thiazolidinedione (TZD). Oral triple therapy, metformin + TZD + incretin-based drug, has several theoretical advantages but is not supported by any published trial. Finally, obtaining the acceptance of injections once to twice daily vs. oral administration of OADs will probably remain difficult during the first years of treatment in many patients. Nevertheless a long-acting release exenatide formulation (i.e. once weekly), for subcutaneous injection in patients with type 2 diabetes under development shows promising preliminary results. If confirmed, the use of this new class of drugs should be largely developed from monotherapy to combinations (bitherapy or tritherapy), and even instead of insulin or in association with insulin. The long-term effect of GLP-1 based agents on glycaemic control has not yet been established, and their potential impact on beta-cell function in humans remains an area of active investigation. So, further studies are required and will allow progressively determining the use of incretin-based agents in T2DM treatment strategy. Their efficacy, safety and their cost vs. older strategies, will be really evaluated by physicians in the real daily practice and by large and long term systematic surveys, as recently shown in other therapeutic fields.     

Efficacy and safety of gemigliptin as add-on therapy to insulin,with or without metformin,in patients with type 2 diabetes mellitus (ZEUS II study)

The objective of this study was to evaluate the efficacy and safety of gemigliptin added to a stable dose of insulin alone or of insulin in combination with metformin in patients with type 2 diabetes mellitus. After a two-week run-in period, patients were randomized 2:1 to receive gemigliptin 50 mg or placebo once daily as add-on to background therapy with insulin or insulin plus metformin for 24 weeks. The primary endpoint was change in haemoglobin A1c (HbA1c) from baseline at Week 24. Baseline characteristics were similar between the gemigliptin (n = 188) and placebo (n = 95) groups in terms of HbA1c (8.1%). At Week 24, the gemigliptin group showed a statistically significant reduction in mean HbA1c from baseline as compared with placebo (between-group mean difference, −0.7% [95% CI, −0.9% to −0.4%]; P-value < 0.0001). The incidence of overall adverse events and the number of hypoglycaemic adverse events were similar between the study groups. Gemigliptin added to insulin alone or to insulin in combination with metformin resulted in superior glycaemic control compared to that in the placebo group and was well tolerated for 24 weeks in patients with type 2 diabetes mellitus, without causing weight gain or increasing the incidence of hypoglycaemia.     

Comparative review of dipeptidyl peptidase‐4 inhibitors and sulphonylureas

Type 2 diabetes (T2DM) is a progressive disease, and pharmacotherapy with a single agent does not generally provide durable glycaemic control over the long term. Sulphonylurea (SU) drugs have a history stretching back over 60 years, and have traditionally been the mainstay choice as second‐line agents to be added to metformin once glycaemic control with metformin monotherapy deteriorates; however, they are associated with undesirable side effects, including increased hypoglycaemia risk and weight gain. Dipeptidyl peptidase (DPP)‐4 inhibitors are, by comparison, more recent, with the first compound being launched in 2006, but the class now globally encompasses at least 11 different compounds. DPP‐4 inhibitors improve glycaemic control with similar efficacy to SUs, but do not usually provoke hypoglycaemia or weight gain, are relatively free from adverse side effects, and have recently been shown not to increase cardiovascular risk in large prospective safety trials. Because of these factors, DPP‐4 inhibitors have become an established therapy for T2DM and are increasingly being positioned earlier in treatment algorithms. The present article reviews these two classes of oral antidiabetic drugs (DPP‐4 inhibitors and SUs), highlighting differences and similarities between members of the same class, as well as discussing the potential advantages and disadvantages of the two drug classes. While both classes have their merits, the choice of which to use depends on the characteristics of each individual patient; however, for the majority of patients, DPP‐4 inhibitors are now the preferred choice.     

Long-term 2-year safety and efficacy of vildagliptin compared with rosiglitazone in drug-naïve patients with type 2 diabetes mellitus

Aims: To assess the long‐term safety and the sustained glycaemic control of vildagliptin compared with rosiglitazone over 2‐year treatment in drug‐naïve type 2 diabetes mellitus patients. Methods: This was an additional 80‐week, multicentre, double‐blind and active‐controlled extension to a 24‐week core study comparing the treatments of vildagliptin (50 mg b.i.d., n = 396) to rosiglitazone (8 mg q.d., n = 202). The primary efficacy variable was the mean change in haemoglobin A1c (HbA1c) from the core study baseline (day 1) to the end of 104 weeks (the extension endpoint). Results: Vildagliptin and rosiglitazone showed statistically significant and sustained HbA1c reductions from a core mean baseline of 8.6 and 8.7% to 7.8 and 7.3% respectively (both significant, p < 0.001). However, rosiglitazone‐treated patients showed significantly greater mean HbA1c reductions (mean difference 0.62%, s.e. 0.13, p < 0.001) compared with vildagliptin. The overall lipid profile significantly improved with vildagliptin compared to rosiglitazone treatment. Body weight remained unchanged in vildagliptin‐treated patients despite improvements in glycaemic control but significantly increased (mean change from core study baseline 4.67 kg) in rosiglitazone‐treated patients (p < 0.001). Notably, a lower incidence of peripheral oedema was seen with vildagliptin (4.6%) compared with rosiglitazone treatment (11.1%). More serious adverse events (SAEs) occurred in vildagliptin‐ than rosiglitazone‐treated patients (12.5 and 9.1% respectively), but only one SAE each in both treatment group was suspected to be related to study drug. Three non‐study drug‐related deaths (vildagliptin: 2 and rosiglitazone: 1) were reported. Four mild hypoglycaemic events were observed with vildagliptin. Conclusions: This study showed that the similar short‐term HbA1c reductions seen with both vildagliptin and rosiglitazone treatments were more durable after 104 weeks of treatment with rosiglitazone than vildagliptin. However, this greater durability with rosiglitazone was at the expense of weight gain (almost 5 kg), higher incidences of peripheral oedema and a less favourable plasma lipid profile compared with vildagliptin.     

Pharmacological management of type 2 diabetes: the potential of incretin-based therapies

Management guidelines recommend metformin as the first-line therapy for most patients with type 2 diabetes uncontrolled by diet and exercise. Efficacy with metformin therapy is usually of limited duration, which necessitates the early introduction of one or two additional oral agents or the initiation of injections, glucagon-like peptide-1 (GLP-1) agonists or insulin. Although safe and effective, metformin monotherapy has been associated with gastrointestinal side effects (≈20% of treated patients in randomized studies) and is contraindicated in patients with renal insufficiency or severe liver disease. Patients treated with a sulphonylurea are at increased risk for hypoglycaemia and moderate weight gain, whereas those receiving a thiazolidinedione are subject to an increased risk of weight gain, oedema, heart failure or fracture. Weight gain and hypoglycaemia are associated with insulin use. Thus, there is an unmet need for a safe and efficacious add-on agent after initial-therapy failure. Evidence suggests that incretin-based agents, such as GLP-1 receptor agonists and dipeptidyl peptidase-4 inhibitors, can successfully achieve glycaemic targets and potentially provide cardiovascular and β-cell-function benefits. This review will examine current approaches for treating type 2 diabetes and discuss the place of incretin therapies, mainly GLP-1 agonists, in the type 2 diabetes treatment spectrum.     

Efficacy and tolerability of initial combination therapy with vildagliptin and pioglitazone compared with component monotherapy in patients with type 2 diabetes

AIM: The aim of this study was to compare efficacy and tolerability of initial combination therapy with vildagliptin/pioglitazone to component monotherapy. METHODS: This 24-week, multicentre, randomized, double-blind, active-controlled study assessed the effects of the dipeptidyl peptidase-4 inhibitor vildagliptin (100 mg q.d.), pioglitazone (30 mg q.d.) and vildagliptin combined with pioglitazone (100/30 mg q.d. or 50/15 mg q.d.) in 607 drug-naive patients with type 2 diabetes (T2DM). The primary outcome measure was change from baseline in HbA(1c) in patients receiving initial combination therapy compared with pioglitazone monotherapy. RESULTS: After 24-week treatment, adjusted mean changes in HbA(1c) from baseline (approximately 8.7%) in patients receiving pioglitazone monotherapy, 50/15 mg combination, 100/30 mg combination and vildagliptin monotherapy were -1.4 +/- 0.1%, -1.7 +/- 0.1%, -1.9 +/- 0.1% and -1.1 +/- 0.1% respectively. Both low-dose and high-dose combinations were significantly more efficacious than pioglitazone alone (p = 0.039 and p < 0.001 respectively). Adjusted mean changes in fasting plasma glucose were -1.9 +/- 0.2, -2.4 +/- 0.2, -2.8 +/- 0.2 and -1.3 +/- 0.2 mmol/l respectively, and both combination groups were significantly more effective than pioglitazone monotherapy (p = 0.022 and p < 0.001 respectively). The overall incidence of adverse events ranged from 45.8% in the low-dose combination to 51.6% in the pioglitazone monotherapy group. The incidence of peripheral oedema was highest in patients receiving pioglitazone monotherapy (9.3%) and lowest in those receiving low-dose combination (3.5%). One mild hypoglycaemic event was reported by one patient receiving high-dose combination and one patient receiving vildagliptin monotherapy. CONCLUSIONS: First-line treatment with vildagliptin/pioglitazone combination in patients with T2DM provides better glycaemic control than either monotherapy component yet has minimal risk of hypoglycaemia and a tolerability profile comparable with component monotherapy.     

Liraglutide - overview of the preclinical and clinical data and its role in the treatment of type 2 diabetes

Type 2 diabetes is characterized by a progressive decline in glycaemic control. Many standard diabetes treatments, however, fail to achieve or maintain glycaemic control, and are often associated with an increased risk of hypoglycaemia and weight gain. Recently developed incretin-based therapies are a promising addition to the current armamentarium of diabetes treatments. Two types of incretin-based therapies are currently available: glucagon-like peptide (GLP)-1 receptor agonists (liraglutide and exenatide) and dipeptidyl peptidase-4 inhibitors (sitaglipin, vildagliptin and saxagliptin). This review aims to summarize the key efficacy and safety data of liraglutide, a once-daily human GLP-1 analogue. Extensive phase III clinical trials have shown liraglutide to improve glycaemic control with additional benefits on body weight, blood pressure and β-cell function. Liraglutide is also generally well tolerated with a low risk of hypoglycaemia. Liraglutide has recently been approved for marketing in Europe, Japan and the USA.