Concept Trial Diabetes Care 2014;37:1480–1483 | DOI: 10.2337/dc13-2338 OBJECTIVE

Adjunctive-to-insulin therapy with sodium-glucose cotransporter 2 (SGLT2) inhi-bition may improve glycemic control in type 1 diabetes (T1D). RESEARCH DESIGN AND METHODS We evaluated the glycemic efficacy and safety of empagliflozin 25 mg daily in 40 patients treated for 8 weeks in a single-arm open-label proof-of-concept trial (NCT01392560). RESULTS Mean A1C decreased from 8.06 0.9 % (646 10mmol/mol) to 7.66 0.9 % (606 10 mmol/mol) (P < 0.0001), fasting glucose from 9.0 6 4.3 to 7.0 6 3.2 mmol/L (P = 0.008), symptomatic hypoglycemia (<3.0 mmol/L) from 0.12 to 0.04 events per patient per day (P = 0.0004), and daily insulin dose from 54.76 20.4 to 45.86 18.8 units/day (P < 0.0001). Mean urinary excretion of glucose increased from 196 19 to 134 6 61 g/day (P < 0.0001). Weight decreased from 72.6 6 12.7 to 70.0 6 12.3 kg (P < 0.0001), and waist circumference decreased from 82.9 6 8.7 to 79.1 6 8.0 cm (P < 0.0001). CONCLUSIONS This proof-of-concept study strongly supports a randomized clinical trial of adjunctive-to-insulin empagliflozin in patients with T1D. Results of animal and short-term human studies have suggested that empagliflozin, a highly potent and selective inhibitor of the renal proximal tubular sodium-glucose cotransporter 2 (SGLT2), may be useful as adjunctive-to-insulin therapy in patients with type 1 diabetes (T1D) to improve glycemic control, hypo-glycemia risk, and weight (1–4). In a single-arm, open-label study designed with the primary objective of investigating renal hemodynamic effects (5), we sought to deter-mine the feasibility, safety, and efficacy of 8 weeks of treatment with empagliflozin on glycemia in patients with T1D