Cancer outcomes and all-cause mortality in adults allocated to metformin: systematic review and collaborative meta-analysis of randomised clinical trials.

AIMS/HYPOTHESIS: Observational studies suggest that metformin may reduce cancer risk by approximately one-third. We examined cancer outcomes and all-cause mortality in published randomised controlled trials (RCTs). METHODS: RCTs comparing metformin with active glucose-lowering therapy or placebo/usual care, with minimum 500 participants and 1-year follow-up, were identified by systematic review. Data on cancer incidence and all-cause mortality were obtained from publications or by contacting investigators. For two trials, cancer incidence data were not available; cancer mortality was used as a surrogate. Summary RRs, 95% CIs and I (2)statistics for heterogeneity were calculated by fixed effects meta-analysis. RESULTS: Of 4,039 abstracts identified, 94 publications described 14 eligible studies. RRs for cancer were available from 11 RCTs with 398 cancers during 51,681 person-years. RRs for all-cause mortality were available from 13 RCTs with 552 deaths during 66,447 person-years. Summary RRs for cancer outcomes in people randomised to metformin compared with any comparator were 1.02 (95% CI 0.82, 1.26) across all trials, 0.98 (95% CI 0.77, 1.23) in a subgroup analysis of active-comparator trials and 1.36 (95% CI 0.74, 2.49) in a subgroup analysis of placebo/usual care comparator trials. The summary RR for all-cause mortality was 0.94 (95% CI 0.79, 1.12) across all trials. CONCLUSIONS/INTERPRETATION: Meta-analysis of currently available RCT data does not support the hypothesis that metformin lowers cancer risk by one-third. Eligible trials also showed no significant effect of metformin on all-cause mortality. However, limitations include heterogeneous comparator types, absent cancer data from two trials, and short follow-up, especially for mortality.

Effects of vildagliptin on glucose control in patients with type 2 diabetes inadequately controlled with a sulphonylurea.

AIM: To compare the efficacy and tolerability of vildagliptin vs. placebo in patients with type 2 diabetes mellitus (T2DM) who are inadequately controlled [haemoglobin A(1c) (HbA(1c)) 7.5 to 11%] with prior sulphonylurea (SU) monotherapy. METHODS: This 24-week, multicentre, randomized, double-blind, placebo-controlled study assessed the effects of the dipeptidyl peptidase-4 inhibitor vildagliptin (50 mg given once or twice daily) vs. placebo added to glimepiride (4 mg once daily) in 515 patients with T2DM. Adjusted mean changes from baseline to end-point (AMDelta) in HbA(1c), fasting plasma glucose, fasting lipids and body weight were compared by analysis of covariance. RESULTS: The between-group difference (vildagliptin - placebo) in AMDelta HbA(1c) was -0.6 +/- 0.1% in patients receiving vildagliptin 50 mg daily and -0.7 +/- 0.1% in those receiving 100 mg daily (p < 0.001 vs. placebo for both). Greater efficacy was seen in patients > or =65 years of age (-0.7 +/- 0.1% and -0.8 +/- 0.2% for 50 and 100 mg daily respectively) and in patients with baseline HbA(1c) > 9% (Delta = -1.0 +/- 0.2% and -0.9 +/- 0.2% for 50 and 100 mg daily respectively). Relative to placebo, patients receiving vildagliptin also had improvements in beta-cell function and postprandial glucose, with small changes in fasting lipids and body weight. The incidences of adverse events (AEs) (67.1, 66.3 and 64.2%) and serious AEs (2.9, 2.4 and 5.1%) were similar in patients receiving 50 mg vildagliptin, 100 mg vildagliptin or placebo respectively. The incidence of hypoglycaemic events was low but slightly higher in the group receiving vildagliptin 100 mg (3.6%) than in the group receiving vildagliptin 50 mg (1.2%) or placebo (0.6%). CONCLUSIONS: In patients with T2DM inadequately controlled with prior SU monotherapy, addition of vildagliptin (50 or 100 mg daily) to glimepiride (4 mg once daily) improves glycaemic control and is well tolerated. Addition of vildagliptin 50 mg daily to SU monotherapy may be a particularly attractive therapy in elderly patients.

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.