Efficacy and safety of dapagliflozin monotherapy in people with Type 2 diabetes: a randomized double-blind placebo-controlled 102-week trial.

AIMS: To assess initial pharmacotherapy of Type 2 diabetes with the sodium-glucose cotransporter-2 inhibitor dapagliflozin. METHODS: This double-blind, placebo-controlled trial, randomly allocated people with Type 2 diabetes aged 18-77 years and inadequate glycaemic control on diet and exercise [HbA1c 53-86 mmol/mol (7.0-10.0%)] to receive placebo (n = 75) or dapagliflozin monotherapy 2.5 mg (n = 65), 5 mg (n = 64) or 10 mg (n = 70) once daily in the morning. After 24 weeks, low-dose double-blind metformin 500 mg/day was added to the placebo group regimen (placebo+low-dose metformin group). Changes in HbA1c level, fasting plasma glucose and body weight, as well as adverse events, were assessed over 102 weeks. RESULTS: Of the 274 participants randomized, 167 completed the study (60.9%). At 102 weeks, significant differences vs placebo+low-dose metformin with dapagliflozin 5 and 10 mg were observed for HbA1c (-5.8 mmol/mol [-0.53%], P = 0.018; and -4.8 mmol/mol [-0.44%], P = 0.048), respectively); and for FPG (-0.69 mmol/L, P = 0.044; and -1.12 mmol/l, P = 0.001, respectively). For body weight, the difference between the dapagliflozin 10-mg group and the placebo+low-dose metformin group was significant (-2.60 kg; P = 0.016). Hypoglycaemic events were uncommon, with rates of 5.3% for placebo+low-dose metformin group and 0-4.6% for the dapagliflozin groups. Genital infections and urinary tract infections were more common in the dapagliflozin groups than in the placebo+low-dose metformin group. CONCLUSIONS: Dapagliflozin as monotherapy in treatment-naïve people with early Type 2 diabetes improved glycaemic control and reduced weight without increasing hypoglycaemia over 102 weeks. Dapagliflozin may provide an alternative initial pharmacotherapy in such people.

Dapagliflozin monotherapy in drug-naïve patients with diabetes: a randomized-controlled trial of low-dose range.

AIMS: Many patients with type 2 diabetes are suboptimally managed with currently available therapies. Dapagliflozin, a sodium-glucose co-transporter-2 inhibitor, has shown efficacy in reducing diabetic hyperglycaemia. This study assessed efficacy of three lower doses in recently diagnosed patients. METHODS: This phase 3, randomized, double-blind, placebo-controlled study assigned treatment-naïve patients to placebo or dapagliflozin monotherapy (1, 2.5 or 5 mg) daily for 24 weeks. Patients were antidiabetic drug-naïve with inadequate glycaemic control [haemoglobin A1c (HbA1c) ≥7.0 and ≤10.0%]. The primary efficacy endpoint was change in HbA1c from baseline. Secondary endpoints included changes in body weight and fasting plasma glucose (FPG), and proportions achieving HbA1c <7%. RESULTS: A total of 282 patients with type 2 diabetes were randomly assigned to one of four treatment groups. Baseline characteristics were similar across groups. At week 24, mean HbA1c reduction was significantly greater with dapagliflozin: -0.68% for 1 mg, -0.72% for 2.5 mg, -0.82% for 5 mg, versus 0.02% for placebo (p < 0.0001); compared to mean baseline values of 7.8-8.1%. Mean FPG reduction was significantly greater for all dapagliflozin groups versus placebo (p < 0.02), as was mean weight reduction (p < 0.003). During the treatment period, 19.1% of placebo-treated patients received rescue medication or discontinued because of poor glycaemic control versus 6.9, 4.1 and 5.9% for dapagliflozin 1, 2.5 and 5 mg, respectively. Percentages of patients experiencing ≥1 adverse event were similar across groups. CONCLUSION: Dapagliflozin at doses of 1, 2.5 and 5 mg/day is effective in reducing glycaemic levels and body weight in treatment-naïve patients with type 2 diabetes. Dapagliflozin was generally well tolerated. This insulin-independent mechanism suggests a new treatment for type 2 diabetes.

Dapagliflozin, metformin XR, or both: initial pharmacotherapy for type 2 diabetes, a randomised controlled trial.

BACKGROUND: Combining metformin (XR) with dapagliflozin to initiate pharmacotherapy in patients with type 2 diabetes (T2D) and high baseline HbA1c may be advantageous. We conducted two randomised, double-blind, three-arm 24-week trials in treatment-naïve patients to compare dapagliflozin plus metformin, dapagliflozin alone and metformin alone. METHODS: Eligible patients had baseline HbA1c 7.5-12%. Each trial had three arms: dapagliflozin plus metformin, dapagliflozin monotherapy and metformin monotherapy. Dapagliflozin in combination and as monotherapy was dosed at 5 mg (Study 1) and 10 mg (Study 2). Metformin in combination and as monotherapy was titrated to 2000 mg. The primary endpoint was HbA1c change from baseline; secondary endpoints included change in fasting plasma glucose (FPG) and weight. RESULTS: In both trials, combination therapy led to significantly greater reductions in HbA1c compared with either monotherapy: -2.05 for dapagliflozin + metformin, -1.19 for dapagliflozin, and -1.35 for metformin (p < 0.0001) (Study 1); -1.98 for dapagliflozin + metformin, -1.45 for dapagliflozin and -1.44 for metformin (p < 0.0001) (Study 2). Combination therapy was statistically superior to monotherapy in reduction of FPG (p < 0.0001 for both studies); combination therapy was more effective than metformin for weight reduction (p < 0.0001). Dapagliflozin 10 mg was non-inferior to metformin in reducing HbA1c (Study 2). Events suggestive of genital infection were reported in 6.7%, 6.9% and 2.0% (Study 1) and 8.5%, 12.8% and 2.4% (Study 2) of patients in combination, dapagliflozin and metformin groups; events suggestive of urinary tract infection were reported in 7.7%, 7.9% and 7.5% (Study 1) and 7.6%, 11.0% and 4.3% (Study 2) of patients in the respective groups. No major hypoglycaemia was reported. CONCLUSION: In treatment-naïve patients with T2D, dapagliflozin plus metformin was generally well tolerated and effective in reducing HbA1c, FPG and weight. Dapagliflozin-induced glucosuria led to an increase in events suggestive of urinary tract and genital infections.

Effects of saxagliptin on ß-cell stimulation and insulin secretion in patients with type 2 diabetes.

AIM: To study the effect of dipeptidyl peptidase-4 (DPP-4) inhibition with saxagliptin on ß-cell function as reflected by the stimulated insulin secretion rate after an enteral glucose load in patients with type 2 diabetes. METHODS: Patients in this randomized, parallel-group, double-blind, placebo-controlled study were drug-naïve, aged 43-69 years, with baseline haemoglobin A1c (HbA1c) 5.9-8.1%. Twenty patients received saxagliptin 5 mg once daily; 16 received placebo. Patients were assessed at baseline and week 12 by intravenous hyperglycaemic clamp (0-180 min, fasting state), and intravenous-oral hyperglycaemic clamp (180-480 min, postprandial state) following oral ingestion of 75 g glucose. Primary and secondary endpoints were percent changes from baseline in insulin secretion during postprandial and fasting states, respectively. Insulin secretion was calculated by C-peptide deconvolution. RESULTS: After 12 weeks, saxagliptin significantly increased insulin secretion percent change from baseline during the postprandial state by an 18.5% adjusted difference versus placebo (p = 0.04), an improvement associated with increased peak plasma concentrations of intact glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide. In the fasting state, saxagliptin significantly increased insulin secretion by a 27.9% adjusted difference versus placebo (p = 0.02). Saxagliptin also improved glucagon area under the curve in the postprandial state (adjusted difference -21.8% vs. placebo, p = 0.03). CONCLUSIONS: DPP-4 inhibition with saxagliptin improves pancreatic ß-cell function in postprandial and fasting states, and decreases postprandial glucagon concentration. Given the magnitude of enhancement of the insulin response in the fasting state, further study into the effect of DPP-4 inhibition on the ß-cell is warranted.

Glucose-lowering activity of the dipeptidyl peptidase-4 inhibitor saxagliptin in drug-naive patients with type 2 diabetes.

AIM: Enhancing the physiologic actions of the endogenous incretin hormones, glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, by inhibiting dipeptidyl peptidase-4 (DPP-4), the enzyme responsible for their degradation, is an emerging treatment for type 2 diabetes mellitus (T2DM). The aim of this study was to evaluate the safety and efficacy of dose ranges of the DPP-4 inhibitor saxagliptin (BMS-477118) in patients with T2DM. METHODS: In a 12-week, multicentre, randomized, parallel-group, double-blind, placebo-controlled trial conducted at 152 out-patient US study centres, 338 (low-dose cohort) and 85 (high-dose cohort) drug-naive patients with T2DM and inadequate glycaemic control (baseline HbA1c > or =6.8 and < or =9.7%) were randomized. Following a 2-week washout, patients received saxagliptin 2.5, 5, 10, 20 or 40 mg once daily, or placebo, for 12 weeks (low-dose cohort). In a second cohort, patients received saxagliptin 100 mg once daily, or placebo, for 6 weeks (high-dose cohort). The main outcome measure was saxagliptin dose response assessed as change from baseline in HbA1c following double-blind treatment. RESULTS: In all treatment arms, saxagliptin significantly reduced HbA1c by 0.7-0.9% from an average baseline of 7.9% vs. placebo (0.3% reduction) in the low-dose cohort. Placebo-subtracted HbA1c reductions were 0.45-0.63% (low-dose cohort). Saxagliptin had significant placebo-subtracted reductions in fasting serum glucose (14-25 mg/dl). Postprandial glucose levels at 60 min following a standard liquid meal test were reduced by 24-41 mg/dl vs. placebo. Saxagliptin was weight neutral. Adverse events were similar across treatment groups, including placebo, with a very low incidence of confirmed hypoglycaemia in saxagliptin treatment arms. CONCLUSIONS: Saxagliptin effectively improved glycaemic control in drug-naive patients with T2DM and was generally safe, with a tolerability profile similar to placebo.

Replication of the origin region of simian virus 40 DNA in permeabilized monkey cells.

Simian virus 40 (SV40) DNA replication was studied in monolayers of infected monkey CV-1 cells, permeabilized with lysolecithin, by incubation with [alpha-32P]dTTP, the other dNTPs and rNTPs and an ATP-regenerating system. Analysis of the labeled SV40 DNA by sedimentation in alkaline sucrose gradients showed that about 30% of the material synthesized by the permeable cells in the course of 60 min consisted of covalently closed circular SV40 DNA (form I), with the remainder sedimenting as relaxed circles (form II) and replicative intermediates between 18 S and 4 S. The synthesis of SV40 DNA in the permeabilized cell system required the presence of all four dNTPs and was completely inhibited by aphidicolin, consistent with the involvement of DNA polymerase alpha. A detailed analysis of the distribution of radioactivity in the DNA synthesized involved cleavage with BstNI restriction endonuclease, followed by polyacrylamide gel electrophoresis and radioautography. The extent of labeling of all restriction fragments was nearly proportional to their length, suggesting that the entire SV40 chromosome was being replicated. This was confirmed by the careful comparison of the rate of labeling of a DNA fragment which includes the replication origin, and a fragment which includes the replication terminus. Their labeling was proportional to their size, regardless of the time for which the labeling was carried out. This demonstrated that the replication of the entire SV40 chromosome occurred in a steady state and that the start and termination of replication continuously occurred throughout the labeling period. The availability of an in vitro system in which replication of SV40 DNA undergoes multiple replication cycles should be of considerable value in the analysis of the mechanism of replication of this viral genome.