YG-1699

YG1699 is a novel inhibitor of sodium‐glucose cotransporter 1 (SGLT1) and SGLT2. This double‐blind, 3‐way crossover trial compared YG1699 to dapagliflozin as an adjunct to insulin in people with type 1 diabetes (T1D) on insulin pump therapy. Treatment periods included four mixed meal tolerance tests (MMTTs) and insulin withdrawal tests per person. Nineteen adults with T1D were randomized to YG1699 10 mg, YG1699 25 mg, and dapagliflozin 10 mg once daily for 1 week in different orders. The primary end point was the difference in area under the curve (AUC) in plasma glucose (AUC0–120min) after an MMTT between treatment groups. Mean change in plasma glucose after an MMTT (AUC0–120min) was lower for YG1699 10 mg vs. dapagliflozin (89.51% of baseline vs. 102.13%, 90% confidence interval (CI) vs. dapagliflozin, −6% to −16%, P = 0.0003) and for YG1699 25 mg (84.83% vs. 102.13%, 90% CI vs. dapagliflozin −13% to −22%, P < 0.0001). At 120 minutes, mean glucose values on no treatment, dapagliflozin, YG1699 10 mg, and YG1699 25 mg were 149 (SE 7.6), 141 (SE 6.1), 128 (SE 6.9), and 115 (SE 7.8) mg/dL, respectively. Insulin dose requirements were lower for YG1699 10 mg and 25 mg vs. dapagliflozin for bolus insulin, and for YG1699 10 mg vs. dapagliflozin for total daily insulin. Safety profiles were similar between treatment groups. YG1699 reduced post‐prandial glucose more than dapagliflozin in people with T1D on insulin pump therapy. The results were consistent with dual SGLT1/SGLT2 inhibition by YG1699.