Saxagliptin given in combination with metformin as initial therapy improves glycaemic control in patients with type 2 diabetes compared with either monotherapy: a randomized controlled trial

Aim: The study aim was to evaluate the efficacy and safety of initial combination therapy with saxagliptin + metformin vs. saxagliptin or metformin monotherapy in treatment‐naïve patients with type 2 diabetes (T2D) and inadequate glycaemic control. Methods: In this multicentre, randomized, double‐blind, active‐controlled phase 3 trial, 1306 treatment‐naïve patients with T2D ≥18 to ≤77 years, glycosylated haemoglobin (HbA1c) ≥8 to ≤12%, fasting C‐peptide concentration ≥1.0 ng/ml, body mass index ≤40 kg/m² were randomized to receive saxagliptin 5 mg + metformin 500 mg, saxagliptin 10 mg + metformin 500 mg, saxagliptin 10 mg + placebo or metformin 500 mg + placebo for 24 weeks. From weeks 1–5, metformin was uptitrated in 500‐mg/day increments to 2000 mg/day maximum in the saxagliptin 5 mg + metformin, saxagliptin 10 mg + metformin and metformin + placebo treatment groups. The main outcome measure was HbA1c change from baseline to week 24. Selected secondary outcomes included change from baseline to week 24 in fasting plasma glucose (FPG), proportion of patients achieving HbA1c <7% and postprandial glucose area under the curve (PPG‐AUC). Results: At 24 weeks, saxagliptin 5 mg + metformin and saxagliptin 10 mg + metformin demonstrated statistically significant adjusted mean decreases vs. saxagliptin 10 mg and metformin monotherapies in HbA1c (?2.5 and ?2.5% vs. ?1.7 and ?2.0%, all p < 0.0001 vs. monotherapy) and FPG (?60 and ?62 mg/dl vs. ?31 and ?47 mg/dl, both p < 0.0001 vs. saxagliptin 10 mg; p = 0.0002 saxagliptin 5 mg + metformin vs. metformin; p < 0.0001 saxagliptin 10 mg + metformin vs. metformin). Proportion of patients achieving an HbA1c <7% was 60.3 and 59.7%, respectively, for saxagliptin 5 mg + metformin and saxagliptin 10 mg + metformin (all p < 0.0001 vs. monotherapy). PPG‐AUC was significantly reduced [?21 080 mg·min/dl (saxagliptin 5 mg + metformin) and ?21 336 mg·min/dl (saxagliptin 10 mg + metformin) vs. ?16 054 mg·min/dl (saxagliptin 10 mg) and ?15 005 mg·min/dl (metformin), all p < 0.0001 vs. monotherapy]. Adverse event occurrence was similar across all groups. Hypoglycaemic events were infrequent. Conclusion: Saxagliptin + metformin as initial therapy led to statistically significant improvements compared with either treatment alone across key glycaemic parameters with a tolerability profile similar to the monotherapy components.     

Initial combination therapy with saxagliptin and metformin provides sustained glycaemic control and is well tolerated for up to 76 weeks

Aim: To assess the efficacy and safety of saxagliptin + metformin initial combination therapy compared with saxagliptin or metformin alone over 76 weeks (24‐week short‐term + 52‐week long‐term extension) in treatment‐naÏve type 2 diabetes mellitus patients with inadequate glycaemic control. Methods: In this phase 3, parallel‐group, double‐blind, active‐controlled study, 1306 patients 18–77 years of age (HbA1c 8.0–12.0%) were randomized to saxagliptin 5 mg + 500 mg metformin, saxagliptin 10 mg + 500 mg metformin, saxagliptin 10 mg + placebo or 500 mg metformin + placebo. Blinded metformin was titrated during weeks 1–5 of the short‐term treatment period in 500 mg/day increments to 2000 mg/day maximum in the metformin‐based treatment groups. No titration of metformin was permitted during the long‐term treatment period. A total of 888 patients completed the study (76 weeks), 613 without being rescued. Changes in HbA1c, fasting plasma glucose, 120‐min postprandial glucose (PPG) and PPG‐area under the curve (AUC) from baseline to week 76 were analysed using a repeated‐measures model. Results: At 76 weeks, adjusted mean changes from baseline HbA1c (95% CI) for saxagliptin 5 mg + metformin, saxagliptin 10 mg + metformin, saxagliptin 10 mg and metformin were ?2.31 (?2.44, ?2.18), ?2.33 (?2.46, ?2.20), ?1.55 (?1.70, ?1.40) and ?1.79% (?1.93, ?1.65), respectively (post hoc and nominal p < 0.0001 vs. metformin and saxagliptin monotherapies for saxagliptin 5 mg + metformin and saxagliptin 10 mg + metformin). The proportions of patients requiring rescue or discontinuation for insufficient glycaemic control were lower for saxagliptin + metformin than for either monotherapy. Little or no attenuation in PPG‐AUC or 120‐min PPG was observed between weeks 24 and 76 for saxagliptin + metformin, indicating persistent efficacy. Adverse event rates were similar across groups; hypoglycaemic events occurred at a low frequency. Conclusion: Saxagliptin + metformin initial combination therapy was well tolerated and produced sustained glycaemic control for up to 76 weeks, with greater improvements in glycaemic parameters compared with either drug alone.     

The effect of initial therapy with the fixed-dose combination of sitagliptin and metformin compared with metformin monotherapy in patients with type 2 diabetes mellitus

Aims: This study was conducted to compare the glycaemic efficacy and safety of initial combination therapy with the fixed‐dose combination of sitagliptin and metformin versus metformin monotherapy in drug‐naive patients with type 2 diabetes. Methods: This double‐blind study (18‐week Phase A and 26‐week Phase B) randomized 1250 drug‐naÏve patients with type 2 diabetes [mean baseline haemoglobin A1c (HbA1c) 9.9%] to sitagliptin/metformin 50/500 mg bid or metformin 500 mg bid (uptitrated over 4 weeks to achieve maximum doses of sitagliptin/metformin 50/1000 mg bid or metformin 1000 bid). Results of the primary efficacy endpoint (mean HbA1c reductions from baseline at the end of Phase A) are reported herein. Results: At week 18, mean change from baseline HbA1c was ?2.4% for sitagliptin/metformin FDC and ?1.8% for metformin monotherapy (p < 0.001); more patients treated with sitagliptin/metformin FDC had an HbA1c value <7% (p < 0.001) versus metformin monotherapy. Changes in fasting plasma glucose were significantly greater with sitagliptin/metformin FDC (?3.8 mmol/l) versus metformin monotherapy (?3.0 mmol/l; p < 0.001). Homeostasis model assessment of β‐cell function (HOMA‐β) and fasting proinsulin/insulin ratio were significantly improved with sitagliptin/metformin FDC versus metformin monotherapy. Baseline body weight was reduced by 1.6 kg in each group. Both treatments were generally well tolerated with a low and similar incidence of hypoglycaemia. Abdominal pain (1.1 and 3.9%; p = 0.002) and diarrhoea (12.0 and 16.6%; p = 0.021) occurred significantly less with sitagliptin/metformin FDC versus metformin monotherapy; the incidence of nausea and vomiting was similar in both groups. Conclusion: Compared with metformin monotherapy, initial treatment with sitagliptin/metformin FDC provided superior glycaemic improvement with a similar degree of weight loss and lower incidences of abdominal pain and diarrhoea.     

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.     

Saxagliptin add‐on therapy in Chinese patients with type 2 diabetes inadequately controlled by insulin with or without metformin: Results from the SUPER study,a randomized,double‐blind,placebo‐controlled trial

This prospective, multicentre, phase III study (NCT02104804) evaluated the efficacy and safety of saxagliptin add‐on therapy in Chinese patients with type 2 diabetes inadequately controlled by insulin ± metformin. Patients with glycated haemoglobin (HbA1c) 7.5% to 10.5% and fasting plasma glucose (FPG) <15 mmol/L (270 mg/dL) on stable insulin therapy (20‐150 U/d) were randomized (1:1) to saxagliptin 5 mg once daily (N = 232) or placebo (N = 230) for 24 weeks, stratified by metformin use. The primary efficacy measure was change in HbA1c. Saxagliptin treatment resulted in a greater adjusted mean change in HbA1c from baseline to week 24 than placebo (?0.58%; P < .001), irrespective of metformin use, and a greater mean change in FPG (0.9 mmol/L [?15.9 mg/dL]; P < .001). More patients achieved HbA1c <7% with saxagliptin (11.4%) than with placebo (3.5%, P = .002). Adverse events and incidence of hypoglycaemia were similar in both groups. Overall, add‐on saxagliptin 5 mg once daily significantly improved glycaemic control without increasing hypoglycaemia risk and was well tolerated in Chinese patients with type 2 diabetes inadequately controlled by insulin (± metformin).     

Safety and efficacy of linagliptin as add‐on therapy to metformin in patients with type 2 diabetes: a randomized,double‐blind,placebo‐controlled study

Aim: To evaluate the efficacy and safety of the potent and selective dipeptidyl peptidase‐4 (DPP‐4) inhibitor linagliptin administered as add‐on therapy to metformin in patients with type 2 diabetes with inadequate glycaemic control. Methods: This 24‐week, randomized, placebo‐controlled, double‐blind, parallel‐group study was carried out in 82 centres in 10 countries. Patients with HbA1c levels of 7.0–10.0% on metformin and a maximum of one additional antidiabetes medication, which was discontinued at screening, continued on metformin ≥1500 mg/day for 6 weeks, including a placebo run‐in period of 2 weeks, before being randomized to linagliptin 5 mg once daily (n = 524) or placebo (n = 177) add‐on. The primary outcome was the change from baseline in HbA1c after 24 weeks of treatment, evaluated with an analysis of covariance (ANCOVA). Results: Mean baseline HbA1c and fasting plasma glucose (FPG) were 8.1% and 9.4 mmol/l, respectively. Linagliptin showed significant reductions vs. placebo in adjusted mean changes from baseline of HbA1c (?0.49 vs. 0.15%), FPG (?0.59 vs. 0.58 mmol/l) and 2hPPG (?2.7 vs. 1.0 mmol/l); all p < 0.0001. Hypoglycaemia was rare, occurring in three patients (0.6%) treated with linagliptin and five patients (2.8%) in the placebo group. Body weight did not change significantly from baseline in both groups (?0.5 kg placebo, ?0.4 kg linagliptin). Conclusions: The addition of linagliptin 5 mg once daily in patients with type 2 diabetes inadequately controlled on metformin resulted in a significant and clinically meaningful improvement in glycaemic control without weight gain or increased risk of hypoglycaemia.     

Efficacy and safety of the dipeptidyl peptidase-4 inhibitor, sitagliptin, in patients with type 2 diabetes mellitus inadequately controlled on glimepiride alone or on glimepiride and metformin

AIM: To assess the efficacy and safety of a 24-week treatment with sitagliptin, a highly selective once-daily oral dipeptidyl peptidase-4 (DPP-4) inhibitor, in patients with type 2 diabetes who had inadequate glycaemic control [glycosylated haemoglobin (HbA(1c)) >or=7.5% and or=4 mg/day) monotherapy and 229 were on glimepiride (>or=4 mg/day) plus metformin (>or=1,500 mg/day) combination therapy. Patients exceeding pre-specified glycaemic thresholds during the double-blind treatment period were provided open-label rescue therapy (pioglitazone) until study end. The primary efficacy analysis evaluated the change in HbA(1c) from baseline to Week 24. Secondary efficacy endpoints included fasting plasma glucose (FPG), 2-h post-meal glucose and lipid measurements. RESULTS: Mean baseline HbA(1c) was 8.34% in the sitagliptin and placebo groups. After 24 weeks, sitagliptin reduced HbA(1c) by 0.74% (p < 0.001) relative to placebo. In the subset of patients on glimepiride plus metformin, sitagliptin reduced HbA(1c) by 0.89% relative to placebo, compared with a reduction of 0.57% in the subset of patients on glimepiride alone. The addition of sitagliptin reduced FPG by 20.1 mg/dl (p < 0.001) and increased homeostasis model assessment-beta, a marker of beta-cell function, by 12% (p < 0.05) relative to placebo. In patients who underwent a meal tolerance test (n = 134), sitagliptin decreased 2-h post-prandial glucose (PPG) by 36.1 mg/dl (p < 0.001) relative to placebo. The addition of sitagliptin was generally well tolerated, although there was a higher incidence of overall (60 vs. 47%) and drug-related adverse experiences (AEs) (15 vs. 7%) in the sitagliptin group than in the placebo group. This was largely because of a higher incidence of hypoglycaemia AEs (12 vs. 2%, respectively) in the sitagliptin group compared with the placebo group. Body weight modestly increased with sitagliptin relative to placebo (+0.8 vs. -0.4 kg; p < 0.001). CONCLUSIONS: Sitagliptin 100 mg once daily significantly improved glycaemic control and beta-cell function in patients with type 2 diabetes who had inadequate glycaemic control with glimepiride or glimepiride plus metformin therapy. The addition of sitagliptin was generally well tolerated, with a modest increase in hypoglycaemia and body weight, consistent with glimepiride therapy and the observed degree of glycaemic improvement.     

Metformin extended‐release versus immediate‐release: An international,randomized, double‐blind,head‐to‐head trial in pharmacotherapy‐naïve patients with type 2 diabetes

This international, randomized, double‐blind trial (NCT01864174) compared the efficacy and safety of metformin extended‐release (XR) and immediate‐release (IR) in patients with type 2 diabetes. After a 4‐week placebo lead‐in, pharmacotherapy‐naïve adults with glycated haemoglobin (HbA1c) at 7.0% to 9.2% were randomized (1:1) to receive once‐daily metformin XR 2000 mg or twice‐daily metformin IR 1000 mg for 24 weeks. The primary endpoint was change in HbA1c after 24 weeks. Secondary endpoints were change in fasting plasma glucose (FPG), mean daily glucose (MDG) and patients (%) with HbA1c <7.0% after 24 weeks. Overall, 539 patients were randomized (metformin XR, N = 268; metformin IR, N = 271). Adjusted mean changes in HbA1c, FPG, MDG and patients (%) with HbA1c <7.0% after 24 weeks were similar for XR and IR: ?0.93% vs ?0.96%; ?21.1 vs ?20.6 mg/dL (?1.2 vs ?1.1 mmol/L); ?24.7 vs ?27.1 mg/dL (?1.4 vs ?1.5 mmol/L); and 70.9% vs 72.0%, respectively. Adverse events were similar between groups and consistent with previous studies. Overall, metformin XR demonstrated efficacy and safety similar to that of metformin IR over 24 weeks, with the advantage of once‐daily dosing.     

Alogliptin as a third oral antidiabetic drug in patients with type 2 diabetes and inadequate glycaemic control on metformin and pioglitazone: a 52-week, randomized, double-blind, active-controlled, parallel-group study

Aim: To assess the efficacy and safety of adding alogliptin versus uptitrating pioglitazone in patients with type 2 diabetes and inadequate glycaemic control on metformin and pioglitazone. Methods: In this randomized, double‐blind, active‐controlled, parallel‐group study, patients with type 2 diabetes and A1c ≥7.0 and ≤10.0% on metformin (≥1500 mg or maximum tolerated dose; Met) and pioglitazone 30 mg (Pio30) received alogliptin 25 mg (Alo25; n = 404) or pioglitazone 15 mg (n = 399) added to Met+Pio30 for 52 weeks. The primary endpoint was change from baseline (CFB) in A1c at weeks 26 and 52, with sequential testing for non‐inferiority of Met+Pio30+Alo25 at weeks 26 and 52 and then for superiority at week 52. Results: Met+Pio30+Alo25 showed superior glycaemic control versus Met+Pio45 at week 52 [least squares (LS) mean CFB in A1c, ?0.70 vs. ?0.29%; p < 0.001]. At week 52, Met+Pio30+Alo25 resulted in greater CFB in A1c regardless of baseline A1c (p < 0.001); higher proportions of patients achieving A1c ≤7.0 (33.2 vs. 21.3%) and ≤6.5% (8.7 vs. 4.3%; p < 0.001); greater CFB in fasting plasma glucose (FPG; LS mean CFB, ?0.8 vs. ?0.2 mmol/L; p < 0.001); and greater improvements in measures of β‐cell function (p < 0.001). Hypoglycaemia incidence was low (Met+Pio30+Alo25, 4.5%; Met+Pio45, 1.5%), mostly mild to moderate, but with two severe events in the Met+Pio30+Alo25 group. No meaningful differences in incidences of individual adverse events were observed between treatments. Conclusions: Adding alogliptin to an existing metformin–pioglitazone regimen provided superior glycaemic control and potentially improved β‐cell function versus uptitrating pioglitazone in patients with type 2 diabetes, with no clinically important differences in safety.     

Initial therapy with the fixed-dose combination of sitagliptin and metformin results in greater improvement in glycaemic control compared with pioglitazone monotherapy in patients with type 2 diabetes

Aims: To evaluate the efficacy and safety of initial therapy with a fixed‐dose combination (FDC) of sitagliptin and metformin compared with pioglitazone in drug‐naÏve patients with type 2 diabetes. Methods: After a 2‐week single‐blind placebo run‐in period, patients with type 2 diabetes, HbA1c of 7.5–12% and not on antihyperglycaemic agent therapy were randomized in a double‐blind manner to initial treatment with a FDC of sitagliptin/metformin 50/500 mg twice daily (N = 261) or pioglitazone 30 mg per day (N = 256). Sitagliptin/metformin and pioglitazone were up‐titrated over 4 weeks to doses of 50/1000 mg twice daily and 45 mg per day, respectively. Both treatments were then continued for an additional 28 weeks. Results: From a mean baseline HbA1c of 8.9% in both groups, least squares (LS) mean changes in HbA1c at week 32 were ?1.9 and ?1.4% for sitagliptin/metformin and pioglitazone, respectively (between‐group difference = ?0.5%; p < 0.001). A greater proportion of patients had an HbA1c of <7% at week 32 with sitagliptin/metformin vs. pioglitazone (57% vs. 43%, p < 0.001). Compared with pioglitazone, sitagliptin/metformin treatment resulted in greater LS mean reductions in fasting plasma glucose (FPG) [?56.0 mg/dl (?3.11 mmol/l) vs. ?44.0 mg/dl (?2.45 mmol/l), p < 0.001] and in 2‐h post‐meal glucose [?102.2 mg/dl (?5.68 mmol/l) vs. ?82.0 mg/dl (?4.56 mmol/l), p < 0.001] at week 32. A substantially greater reduction in FPG [?40.5 mg/dl (?2.25 mmol/l) vs. ?13.0 mg/dl (?0.72 mmol/l), p < 0.001] was observed at week 1 with sitagliptin/metformin vs. pioglitazone. A greater reduction in the fasting proinsulin/insulin ratio and a greater increase in homeostasis model assessment of β‐cell function (HOMA‐β) were observed with sitagliptin/metformin than with pioglitazone, while greater decreases in fasting insulin and HOMA of insulin resistance (HOMA‐IR), and a greater increase in quantitative insulin sensitivity check index (QUICKI) were observed with pioglitazone than with sitagliptin/metformin. Both sitagliptin/metformin and pioglitazone were generally well tolerated. Sitagliptin/metformin led to weight loss (?1.4 kg), while pioglitazone led to weight gain (3.0 kg) (p < 0.001 for the between‐group difference). Higher incidences of diarrhoea (15.3% vs. 4.3%, p < 0.001), nausea (4.6% vs. 1.2%, p = 0.02) and vomiting (1.9% vs. 0.0%, p = 0.026), and a lower incidence of oedema (1.1% vs. 7.0%, p < 0.001), were observed with sitagliptin/metformin vs. pioglitazone. The between‐group difference in the incidence of hypoglycaemia did not reach statistical significance (8.4 and 4.3% with sitagliptin/metformin and pioglitazone, respectively; p = 0.055). Conclusion: Compared with pioglitazone, initial therapy with a FDC of sitagliptin and metformin led to significantly greater improvement in glycaemic control as well as a higher incidence of prespecified gastrointestinal adverse events, a lower incidence of oedema and weight loss vs. weight gain.     

Efficacy and safety of the dipeptidyl peptidase-4 inhibitor, sitagliptin, compared with the sulfonylurea, glipizide, in patients with type 2 diabetes inadequately controlled on metformin alone: a randomized, double-blind, non-inferiority trial

AIM: To compare the efficacy and safety of sitagliptin vs. glipizide in patients with type 2 diabetes and inadequate glycaemic control [haemoglobin A(1c) (HbA(1c)) > or = 6.5 and < or = 10%] on metformin monotherapy. METHODS: After a metformin dose titration/stabilization period (> or = 1500 mg/day), 1172 patients were randomized to the addition of sitagliptin 100 mg q.d. (N = 588) or glipizide 5 mg/day (uptitrated to a potential maximum 20 mg/day) (N = 584) for 52 weeks. The primary analysis assessed whether sitagliptin was non-inferior to glipizide regarding HbA(1c) changes from baseline at Week 52 using a per-protocol approach. RESULTS: From a mean baseline of 7.5%, HbA(1c) changes from baseline were -0.67% at Week 52 in both groups, confirming non-inferiority. The proportions achieving an HbA(1c) < 7% were 63% (sitagliptin) and 59% (glipizide). Fasting plasma glucose changes from baseline were -0.56 mmol/l (-10.0 mg/dl) and -0.42 mmol/l (-7.5 mg/dl) for sitagliptin and glipizide, respectively. The proportion of patients experiencing hypoglycaemia episodes was significantly (p < 0.001) higher with glipizide (32%) than with sitagliptin (5%), with 657 events in glipizide-treated patients compared with 50 events in sitagliptin-treated patients. Sitagliptin led to weight loss (change from baseline =-1.5 kg) compared with weight gain (+1.1 kg) with glipizide [between-treatment difference (95% confidence interval) =-2.5 kg (-3.1, -2.0); p < 0.001]. CONCLUSIONS: In this study, the addition of sitagliptin compared with glipizide provided similar HbA(1c)-lowering efficacy over 52 weeks in patients on ongoing metformin therapy. Sitagliptin was generally well tolerated, with a lower risk of hypoglycaemia relative to glipizide and with weight loss compared with weight gain with glipizide.     

Dutogliptin,a selective DPP4 inhibitor,improves glycaemic control in patients with type 2 diabetes: a 12‐week,double‐blind,randomized, placebo‐controlled,multicentre trial

Aim: To determine efficacy and tolerability of dutogliptin, a dipeptidyl peptidase 4 (DPP4) inhibitor, in patients with type 2 diabetes mellitus. Methods: This was a 12‐week, multicentre, randomized, double‐blind, placebo‐controlled trial in 423 patients with type 2 diabetes with suboptimal metabolic control. Following a 2‐week single‐blind placebo run‐in, patients aged 18–75 years with a body mass index of 25–48 kg/m² and baseline HbA1c of 7.3–11.0% were randomized 2:2:1 to receive once‐daily oral therapy with either dutogliptin (400 or 200 mg) or placebo on a background medication of either metformin alone, a thiazolidinedione (TZD) alone or a combination of metformin plus a TZD. Results: Average HbA1c at baseline was 8.4%. Administration of dutogliptin 400 and 200 mg for 12 weeks decreased HbA1c by ?0.52% (p < 0.001) and ?0.35% (p = 0.006), respectively (placebo‐corrected values), with absolute changes in HbA1c for the 400 mg, 200 mg and placebo groups of ?0.82, ?0.64 and ?0.3%, respectively. The proportion of patients achieving an HbA1c < 7% was 27, 21 and 12% at dutogliptin doses of 400 and 200 mg or placebo, respectively (p = 0.008 for comparison of 400 mg vs. placebo). Fasting plasma glucose (FPG) levels were significantly reduced in both active treatment groups compared to placebo: the placebo‐corrected difference was ?1.00 mmol/l (p < 0.001) for the 400 mg group and ?0.88 mmol/l (p = 0.003) for the 200 mg group. Dutogliptin caused significantly greater reductions in postprandial glucose AUC _0–2h in both the 400 and 200 mg groups (placebo corrected values ?2.58 mmol/l/h, p < 0.001 and ?1.63 mmol/l/h, p = 0.032, respectively). In general, patients tolerated the study drug well. There were minor, not clinically meaningful differences in adverse events (AEs) between dutogliptin‐treated patients and placebo controls, and 60% of all reported AEs were mild. Vital signs and body weight were stable, and routine safety laboratory parameters did not change compared with placebo. Trough ex vivo DPP4 inhibition at the end of the 12‐week treatment period was 80 and 70%, at the 400 and 200 mg doses of dutogliptin, respectively. Conclusions: Dutogliptin treatment for 12 weeks improved glycaemic control in patients with type 2 diabetes who were on a background medication of metformin, a TZD or metformin plus a TZD. Tolerability was favourable for both doses tested. The 400 mg dose of dutogliptin resulted in larger changes of HbA1c and FPG and more subjects reached an HbA1c target of < 7% than the 200 mg dose.     

Initial combination of linagliptin and metformin improves glycaemic control in type 2 diabetes: a randomized, double-blind, placebo-controlled study

Aims: To evaluate the efficacy and safety of initial combination therapy with linagliptin plus metformin versus linagliptin or metformin monotherapy in patients with type 2 diabetes. Methods: In this 24‐week, double‐blind, placebo‐controlled, Phase III trial, 791 patients were randomized to one of six treatment arms. Two free combination therapy arms received linagliptin 2.5 mg twice daily (bid) + either low (500 mg) or high (1000 mg) dose metformin bid. Four monotherapy arms received linagliptin 5 mg once daily, metformin 500 mg or 1000 mg bid or placebo. Patients with haemoglobin A1c (HbA1c) ≥11.0% were not eligible for randomization and received open‐label linagliptin + high‐dose metformin. Results: The placebo‐corrected mean (95% confidence interval) change in HbA1c from baseline (8.7%) to week 24 was ?1.7% (?2.0, ?1.4) for linagliptin + high‐dose metformin, ?1.3% (?1.6, ?1.1) for linagliptin + low‐dose metformin, ?1.2% (?1.5, ?0.9) for high‐dose metformin, ?0.8% (?1.0, ?0.5) for low‐dose metformin and ?0.6 (?0.9, ?0.3) for linagliptin (all p < 0.0001). In the open‐label arm, the mean change in HbA1c from baseline (11.8%) was ?3.7%. Hypoglycaemia occurred at a similar low rate with linagliptin + metformin (1.7%) as with metformin alone (2.4%). Adverse event rates were comparable across treatment arms. No clinically significant changes in body weight were noted. Conclusions: Initial combination therapy with linagliptin plus metformin was superior to metformin monotherapy in improving glycaemic control, with a similar safety and tolerability profile, no weight gain and a low risk of hypoglycaemia.     

Efficacy, dose-response relationship and safety of once-daily extended-release metformin (Glucophage XR) in type 2 diabetic patients with inadequate glycaemic control despite prior treatment with diet and exercise: results from two double-blind, placebo-controlled studies

AIM: The efficacy, dose-response relationships and safety of an extended-release formulation of metformin (Glucophage) XR) were evaluated in two double-blind, randomized, placebo-controlled studies of 24 and 16 weeks' duration, in patients with inadequate glycaemic control despite diet and exercise. Protocol 1 provided an evaluation of metformin XR at a commonly used dosage. Protocol 2 evaluated different dosages of metformin XR. METHODS: In Protocol 1, 240 patients were randomized to receive metformin XR 1000 mg once daily. or placebo in a 2:1 ratio for 12 weeks (patients could receive metformin XR 1500 mg during weeks 12-24 if required). In Protocol 2, 742 patients were randomized to receive metformin XR 500 mg once daily, 1000 mg once daily, 1500 mg once daily, 2000 mg once daily, 1000 mg twice daily or placebo for 16 weeks. The primary endpoint in each study was the change from baseline in HbA(1C) at 12 weeks (Protocol 1) or 16 weeks (Protocol 2). RESULTS: Metformin XR reduced HbA(1C) in Protocol 1, with mean treatment differences for 1000 mg once daily vs. placebo of -0.7% at 12 weeks and -0.8% at 24 weeks (p < 0.001 for each). In Protocol 2, a clear dose-response relationship was evident at doses up to 1500 mg, with treatment differences vs. placebo of -0.6% (500 mg once daily), -0.7% (1000 mg once daily), -1.0% (1500 mg once daily) and -1.0% (2000 mg once daily). The efficacy of metformin XR 2000 mg once daily and 1000 mg twice daily were similar (mean treatment differences vs. placebo in HbA(1C) were -1.0% and -1.2%, respectively). More patients achieved HbA(1C) < 7.0% with metformin XR vs. placebo in Protocol 1 (29% vs. 14% at 12 weeks) and with once-daily metformin XR in Protocol 2 (up to 36% vs. 10% at 16 weeks). No significant changes in fasting insulin or body weight occurred. Total and low-density lipoprotein (LDL)-cholesterol improved (p < 0.05-p < 0.001) in metformin XR groups in Protocol 2. Metformin XR was well tolerated; gastrointestinal side effects were more common with metformin XR vs. placebo, but few patients withdrew for this reason (1.3% vs. 1.3% in Protocol 1 and 1.6% vs. 0.9% in Protocol 2). CONCLUSIONS: Once-daily metformin XR presents an effective and well-tolerated therapeutic option for delivering metformin in a convenient manner, which supports good compliance with therapy.     

Efficacy and safety of vildagliptin and voglibose in Japanese patients with type 2 diabetes: a 12‐week,randomized, double‐blind,active‐controlled study

Aim: To confirm the efficacy of vildagliptin in patients with type 2 diabetes (T2D) by testing the hypothesis that glycosylated haemoglobin (HbA1c) reduction with vildagliptin is superior to that with voglibose after 12 weeks of treatment. Methods: In this 12‐week, randomized, double‐blind, active‐controlled, parallel‐group study, the efficacy and safety of vildagliptin (50 mg bid, n = 188) was compared with that of voglibose (0.2 mg tid, n = 192) in patients with T2D who were inadequately controlled with diet and exercise. Results: The characteristics of two groups were well matched at baseline. The mean age, body mass index (BMI) and HbA1c were 59.1 years, 24.9 kg/m² and 7.6%, respectively. At baseline, fasting plasma glucose (FPG) and 2‐h postprandial glucose (PPG) were 9.01 mmol/l (162.2 mg/dl) and 13.57 mmol/l (244.3 mg/dl), respectively. The adjusted mean change in HbA1c from baseline to endpoint was ?0.95 ± 0.04% in the vildagliptin‐treated patients and ?0.38 ± 0.04% in those receiving voglibose (between‐group change = 0.57 ± 0.06%, 95% confidence interval (CI) (?0.68 to ?0.46%), p < 0.001), showing that vildagliptin was superior to voglibose. Endpoint HbA1c ≤ 6.5% was achieved in 51% vildagliptin‐treated patients compared with 24% patients who were on voglibose (p < 0.001). Vildagliptin also exhibited significantly (p < 0.001) greater reduction compared with voglibose in both FPG [1.34 vs. 0.43 mmol/l (24.1 vs. 7.8 mg/dl)] and 2‐h PPG [2.86 vs. 1.1 mmol/l (51.5 vs. 19.8 mg/dl)]. Overall adverse events (AEs) were lower in the vildagliptin‐treated patients compared with that in the voglibose‐treated patients (61.2 vs. 71.4%), with no incidence of hypoglycaemia and serious adverse events with vildagliptin. Gastrointestinal AEs were significantly lower with vildagliptin compared with that of the voglibose (18.6 vs. 32.8%; p = 0.002). Conclusions: Vildagliptin (50 mg bid) showed superior efficacy and better tolerability compared with voglibose in Japanese patients with T2D.     

The effect of linagliptin on glycaemic control and tolerability in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

Aim: Linagliptin is a new dipeptidyl peptidase‐4 inhibitor recently approved for use in the USA. The objective of this systematic review and meta‐analysis was to assess effect of linagliptin on glycaemic control, biomarkers and incidence of adverse events (AEs) in patients with type 2 diabetes mellitus. Methods: Five published and four unpublished randomized, clinical trials were identified from multiple databases. Qualitative assessments and quantitative analyses were performed. Results: Nine studies included 4246 participants with 53% men, 59.4% Caucasians, 38.7% Asians, and age range 45–69 years. Linagliptin was given as monotherapy (vs. placebo) or combined with metformin (vs. metformin + placebo), sulphonylurea (vs. sulphonylurea + placebo) or pioglitazone (vs. pioglitazone + placebo). Linagliptin 5 mg/day for 12–24 weeks, significantly reduced haemoglobin A1c (HbA1c) (?0.63%, p < 0.00001), fasting plasma glucose (FPG) (?1.01 mmol/l, p < 0.00001) and improved disposition index (DI, product of insulin sensitivity and acute insulin secretion) (p = 0.0001). Linagliptin monotherapy was not more effective than metformin at reducing HbA1c or FPG. Similar proportion of patients in linagliptin and placebo groups reported AEs including upper respiratory tract infections, headaches, nausea, hypertension and back pain. Conclusions: Linagliptin was associated with modest but significant reduction in HbA1c and FPG and improved DI after 12–24 weeks. Patients who would probably benefit most are those with HbA1c <9%, already on an active agent, compliant with weight reduction strategies, and can recognize and manage hypoglycaemia, fluid retention and upper respiratory tract infections. Long‐term studies are needed to determine durability of response, incidence of microvascular and macrovacular complications, cost‐effectiveness and safety.     

Effect of adding sitagliptin, a dipeptidyl peptidase-4 inhibitor, to metformin on 24-h glycaemic control and beta-cell function in patients with type 2 diabetes

AIM: The aim of this study was to assess the effect of sitagliptin, a dipeptidyl peptidase-4 inhibitor, on 24-h glucose control when added to the regimen of patients with type 2 diabetes who had inadequate glycaemic control on metformin therapy. METHODS: In a double-blind, randomized, placebo-controlled, two-period crossover study, patients with type 2 diabetes with inadequate glycaemic control on metformin monotherapy (i.e. on a stable dose of > or = 1500 mg/day for > or = 6 weeks prior to the screening visit and an haemoglobin A(1c) (HbA(1c)) > or = 6.5% and <10% and fasting plasma glucose (FPG) < or = 240 mg/dl) were recruited for participation. A total of 28 patients (baseline HbA(1c) range = 6.5-9.6%) receiving metformin were randomized into one of two treatment sequences: the addition of placebo for 4 weeks followed by the addition of sitagliptin 50 mg twice daily (b.i.d.) for 4 weeks, or vice versa. At the end of each treatment period, patients were domiciled for frequent blood sampling over 24 h. The primary endpoint was 24-h weighted mean glucose (WMG) and secondary endpoints included change in FPG, mean of 7 daily self-blood glucose measurements (MDG) and fructosamine. beta-cell function was assessed from glucose and C-peptide concentrations were measured during the 5-h period after a standard breakfast meal by using the C-peptide minimal model. RESULTS: Despite a carryover effect from period 1 to period 2, the combined period 1 and period 2 results for glycaemic endpoints were statistically significant for sitagliptin relative to placebo when added to ongoing metformin therapy. To account for the carryover effect, the period 1 results were also compared between the groups. Following period 1, there were significant least-squares (LS) mean reductions in 24-h WMG of 32.8 mg/dl, significant LS mean reduction from baseline in MDG of 28 mg/dl, FPG of 20.3 mg/dl and fructosamine of 33.7 mmol/l in patients treated with sitagliptin relative to placebo (p < 0.05). When added to ongoing metformin therapy, parameters of beta-cell function were significantly improved with sitagliptin compared with placebo. No weight gain or increases in gastrointestinal adverse events or hypoglycaemia events were observed with sitagliptin relative to placebo during this study. CONCLUSIONS: In this study, the addition of sitagliptin 50 mg b.i.d. to ongoing metformin therapy improved 24-h glycaemic control and beta-cell function, and was generally well tolerated in patients with type 2 diabetes.     

Efficacy and tolerability of vildagliptin vs. pioglitazone when added to metformin: a 24-week, randomized, double-blind study

Aim: The aim of this study was to compare the efficacy and tolerability of vildagliptin vs. pioglitazone as add‐on therapy in patients with type 2 diabetes inadequately controlled with metformin monotherapy. Methods: This 24‐week, multicentre, double‐blind, randomized, active‐controlled study compared vildagliptin (100 mg daily, given as equally divided doses, n = 295) and pioglitazone (30 mg daily, given as a single q.d. dose, n = 281) in patients with inadequate glycaemic control (A1C 7.5–11%) while receiving a stable metformin dose (≥1500 mg daily). The adjusted mean changes from baseline to study endpoint (AMΔ) in A1C, fasting plasma glucose (FPG), fasting lipids and body weight were compared by analysis of covariance. Results: When added to a stable dose of metformin (mean dose at baseline >2000 mg/day), both vildagliptin and pioglitazone decreased A1C (AMΔ = ?0.9 ± 0.1% and ?1.0 ± 0.1%, respectively) from identical baseline values (8.4 ± 0.1%). The between‐group difference in AMΔ A1C was 0.1 ± 0.1%, and non‐inferiority of vildagliptin to pioglitazone was established at both 0.4 and 0.3% margins for upper limit of the 95% confidence intervals. Pioglitazone decreased FPG (AMΔ = ?2.1 ± 0.1 mmol/l) to a greater extent than vildagliptin (AMΔ = ?1.4 ± 0.1 mmol/l), but only pioglitazone increased body weight (AMΔ = +1.9 ± 0.2 kg: between‐group difference = ?1.6 ± 0.3 kg, p < 0.001). Adverse events (AEs) were reported by 60% of vildagliptin‐treated patients and by 56.4% of pioglitazone‐treated patients; serious AEs were reported by 2.0 and 4.6% of patients receiving vildagliptin and pioglitazone respectively. Mild hypoglycaemia was reported by one patient (0.3%) in the vildagliptin group and by no patients receiving pioglitazone. Conclusions: When added to metformin, the efficacy of vildagliptin is non‐inferior to that of pioglitazone. The treatments were similarly well tolerated, but only pioglitazone increased body weight.     

Efficacy and safety of sitagliptin monotherapy compared with voglibose in Japanese patients with type 2 diabetes: a randomized,double‐blind trial

Objective: To compare the efficacy and safety of sitagliptin (a dipeptidyl peptidase‐4 inhibitor) and voglibose (an α‐glucosidase inhibitor) monotherapy in Japanese patients with type 2 diabetes who have inadequate glycaemic control (HbA1c ≥6.5% and <10.0%) on diet and exercise. Methods: In a multi‐center, randomized, double‐blind, parallel‐group study, 319 patients were randomized (1:1) to 12‐week treatment with sitagliptin 50 mg once daily or voglibose 0.2 mg thrice daily before meals. The primary analysis assessed whether sitagliptin was non‐inferior to voglibose in lowering HbA1c. Results: After 12 weeks, sitagliptin was non‐inferior to voglibose for HbA1c‐lowering efficacy. Furthermore, sitagliptin was superior to voglibose, providing significantly greater reductions in HbA1c from baseline [least squares mean changes in HbA1c [95% confidence intervals (CI)] = ?0.7% (?0.8 to ?0.6) and ?0.3% (?0.4 to ?0.2), respectively; between‐group difference = ?0.4% (?0.5 to ?0.3), p < 0.001]. Sitagliptin was also superior to voglibose on other key efficacy endpoints, including change from baseline in 2‐h postmeal glucose (?2.8 mmol/l vs. ?1.8 mmol/l, p < 0.001) and fasting plasma glucose (?1.1 mmol/l vs. ?0.5 mmol/l, p < 0.001). After 12 weeks, the incidences of clinical adverse experiences (AEs), drug‐related AEs and gastrointestinal AEs in the sitagliptin group (48.5, 10.4 and 18.4%, respectively) were significantly (p < 0.05) lower than those in the voglibose group (64.7, 26.3 and 34.6%, respectively). The incidences of hypoglycaemia, serious AEs and discontinuations due to AEs were low and similar in both groups. Conclusions: In Japanese patients with type 2 diabetes, once‐daily sitagliptin monotherapy showed greater efficacy and better tolerability than thrice‐daily voglibose over 12 weeks.     

Efficacy and safety of triple therapy with dapagliflozin add‐on to saxagliptin plus metformin over 52 weeks in patients with type 2 diabetes

We previously reported that dapagliflozin versus placebo as add‐on to saxagliptin plus metformin resulted in greater reductions in glycated haemoglobin (A1C), fasting plasma glucose (FPG) and body weight (BW) after 24 weeks of treatment in patients with type 2 diabetes (T2D). Here we report results after 52 weeks of treatment. Patients stabilized on open‐label metformin and saxagliptin 5 mg/day for 8‐16 weeks were randomized to placebo or dapagliflozin 10 mg/day plus open‐label saxagliptin plus metformin for 52 weeks. Changes from baseline to week 52 were greater with dapagliflozin versus placebo in A1C (?0.74% vs. 0.07%), FPG (?27 vs. 10 mg/dL) and BW (?2.1 vs. ?0.4 kg). More patients achieved A1C <7% with dapagliflozin (29.4%) versus placebo (12.6%). Adverse events were similar with dapagliflozin (66%) and placebo (71%), and hypoglycaemia was rare (≤2%). Genital infections occurred more often with dapagliflozin (6%) than with placebo (1%); frequency of urinary tract infections was similar between the two groups (9% vs. 10%). Triple therapy with dapagliflozin add‐on to saxagliptin plus metformin is a durable, effective and well‐tolerated intervention for the treatment of T2D.