Durability of glycaemic efficacy over 2 years with dapagliflozin versus glipizide as add-on therapies in patients whose type 2 diabetes mellitus is inadequately controlled with metformin.

AIMS: To assess the long-term glycaemic durability, safety and tolerability of dapagliflozin versus glipizide as add-on therapies in patients with type 2 diabetes inadequately controlled by metformin alone.

METHODS: This was a 52-week, randomised, double-blind study of dapagliflozin (n = 406) versus glipizide (n = 408), uptitrated over 18 weeks according to tolerability and glycaemic response to a maximum of 10 and 20 mg/day, respectively, as add-on therapies to metformin (≥ 1500 mg/day) with a 156-week double-blind extension period. Data over 104 weeks are reported here.

RESULTS: In total, 53.1% of patients completed 104 weeks of treatment. After the greater initial decrease (0-18 weeks) in glycated haemoglobin (HbA1c) with glipizide, the 18-104-week HbA1c coefficient of failure (CoF) was lower with dapagliflozin (0.13%/year) than with glipizide (0.59%/year), resulting in significant dapagliflozin versus glipizide differences of -0.46%/year (95% CI -0.60,-0.33; p = 0.0001) for CoF and -0.18%(-2.0 mmol/mol) [95% CI -0.33(-3.6),-0.03(-0.3); p = 0.021] for 104-week HbA1c. Dapagliflozin produced sustained reductions in weight and systolic blood pressure, whereas glipizide increased weight and systolic blood pressure, giving 104-week dapagliflozin versus glipizide differences of -5.1 kg (95% CI: -5.7,-4.4) and -3.9 mmHg (95% CI: -6.1,-1.7), respectively. Over 104 weeks, the hypoglycaemia rate was 10-fold lower with dapagliflozin than with glipizide (4.2 vs. 45.8%), whereas patient proportions with events suggestive of genital infection and of urinary tract infection (UTI) were greater with dapagliflozin (14.8 and 13.5%, respectively) than with glipizide (2.9 and 9.1%, respectively).

CONCLUSIONS: Over 2 years, compared with glipizide, dapagliflozin demonstrated greater glycaemic durability, sustained reductions in weight and systolic blood pressure and a low hypoglycaemia rate; however, genital infections and UTIs occurred more frequently.