Efficacy and Safety of Canagliflozin, an Inhibitor of Sodium–Glucose Cotransporter 2, When Used in Conjunction With Insulin Therapy in Patients With Type 2 Diabetes

OBJECTIVE There are limited data about the effects of sodium–glucose cotransporter 2 inhibitors when used with insulin. We report the efficacy and safety of canagliflozin in patients with type 2 diabetes using insulin. RESEARCH DESIGN AND METHODS The CANagliflozin CardioVascular Assessment Study is a double-blind, placebo-controlled study that randomized participants to placebo, canagliflozin 100 mg, or canagliflozin 300 mg once daily, added to a range of therapies. The primary end point of this substudy was the change in HbA1c from baseline at 18 weeks among patients using insulin; 52-week effects were also examined. RESULTS Individuals receiving insulin at baseline were randomized to receive placebo ( n = 690), canagliflozin 100 mg ( n = 692), or canagliflozin 300 mg ( n = 690). These individuals were 66% male and had a median age of 63 years, mean HbA1c of 8.3% (67 mmol/mol), BMI of 33.1 kg/m2, estimated glomerular filtration rate of 75 mL/min/1.73 m2, fasting plasma glucose of 9.2 mmol/L, and a median daily insulin dose of 60 IU. Most individuals were using basal/bolus insulin. Reductions in HbA1c with canagliflozin 100 and 300 mg versus placebo were −0.62% (95% CI −0.69, −0.54; −6.8 mmol/mol [95% CI −7.5, −5.9]; P < 0.001) and −0.73% (95% CI −0.81, −0.65; −8.0 mmol/mol [95% CI −8.9, −7.1]; P < 0.001) at 18 weeks and −0.58% (95% CI −0.68, −0.48; −6.3 mmol/mol [95% CI −7.4, −5.2]) and −0.73% (95% CI −0.83, −0.63; −8.0 mmol/mol [95% CI −9.1, −6.9]) at 52 weeks. There were significant falls in fasting plasma glucose, body weight, and blood pressure at both time points and there was a greater incidence of hypoglycemia, genital mycotic infections, and hypovolemia with both canagliflozin doses. CONCLUSIONS Canagliflozin added to insulin therapy improved glycemic control and decreased body weight. There was a greater frequency of several anticipated side effects, although few led to discontinuation of treatment.