Insulin adjustments to maintain glycemic control in individuals with type 1 diabetes often lead to wide glucose fluctuations, hypoglycemia, and increased body weight. Dapagliflozin, an insulin-independent sodium-glucose cotransporter 2 (SGLT2) inhibitor, increases glucosuria and reduces hyperglycemia in individuals with type 2 diabetes. The primary objective of this study was to assess short-term safety of dapagliflozin in combination with insulin; secondary objectives included pharmacokinetic, pharmacodynamic, and efficacy parameters.