Sotagliflozin (SOTA) is a dual SGLT1 and SGLT2 inhibitor in development as adjunct therapy to insulin in T1D. In this double-blind, 52-week study, 782 adults with T1D treated with multiple daily insulin injections or pump therapy were randomized 1:1:1 to placebo (n=258), SOTA 200 mg (n=261) or SOTA 400 mg (n=263) once daily after 6 weeks of insulin optimization. Primary endpoint was change from baseline in A1C at Week 24. Other endpoints included A1C, documented hypoglycemia (DH), weight and FPG change at Week 52, patient (pt) reported outcomes (PROs) and net clinical benefit (NCB), assessing the proportion of pts with A1C Baseline characteristics were similar between groups. Compared with placebo, treatment with SOTA 200 or 400 mg improved A1C and pt satisfaction at Week 24 and reduced A1C, DH rate, weight, FPG and pt distress at Week 52 (Table). More pts achieved NCB in the SOTA arms vs. placebo (Table). Pts receiving SOTA 400 mg had the least SH events, but more genital mycotic infections, DKA and diarrhea than placebo. In conclusion, SOTA 200 and 400 mg were associated with statistically significant A1C reductions that were sustained (P Disclosure T. Danne: Speaker9s Bureau; Self; A. Menarini Diagnostics. Advisory Panel; Self; Abbott, AstraZeneca, Bayer AG, Boehringer Ingelheim GmbH. Speaker9s Bureau; Self; Dexcom, Inc.. Research Support; Self; Eli Lilly and Company. Stock/Shareholder; Self; DreaMed Diabetes, Ltd.. Research Support; Self; Insulet Corporation. Speaker9s Bureau; Self; Menarini Group. B. Cariou: Board Member; Self; Amgen Inc.. Consultant; Self; Genfit. Board Member; Self; Novo Nordisk A/S. Speaker9s Bureau; Self; Merck Sharp & Dohme Corp.. Board Member; Self; Sanofi-Aventis, Regeneron Pharmaceuticals, Inc. P.L. Banks: Employee; Self; Lexicon Pharmaceuticals, Inc. M. Brandle: Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc.. Advisory Panel; Self; AstraZeneca, Merck Sharp & Dohme Corp.. Research Support; Self; Novo Nordisk Foundation. Speaker9s Bureau; Self; Novartis Pharmaceuticals Corporation. H. Brath: Speaker9s Bureau; Self; Abbott. Advisory Panel; Self; Amgen Inc.. Speaker9s Bureau; Self; Amgen Inc.. Advisory Panel; Self; AstraZeneca. Speaker9s Bureau; Self; AstraZeneca. Advisory Panel; Self; Boehringer Ingelheim GmbH. Speaker9s Bureau; Self; Boehringer Ingelheim GmbH, Eli Lilly and Company, Medtronic. Advisory Panel; Self; Merck Sharp & Dohme Corp.. Speaker9s Bureau; Self; Merck Sharp & Dohme Corp.. Advisory Panel; Self; Novartis AG. Speaker9s Bureau; Self; Novartis AG. Advisory Panel; Self; Novo Nordisk Inc.. Speaker9s Bureau; Self; Novo Nordisk Inc., Pfizer Inc.. Advisory Panel; Self; Sanofi-Aventis Deutschland GmbH. Speaker9s Bureau; Self; Sanofi-Aventis Deutschland GmbH. Board Member; Self; Austrian Diabetes Association. E. Franek: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim GmbH, Merck Sharp & Dohme Corp., Novo Nordisk A/S. Speaker9s Bureau; Self; AstraZeneca, Bristol-Myers Squibb Company, Boehringer Ingelheim GmbH, Eli Lilly and Company, Merck & Co., Inc., Merck Sharp & Dohme Corp., Novo Nordisk A/S, Servier. J.A. Kushner: Advisory Panel; Self; Lexicon Pharmaceuticals, Inc.. Consultant; Self; KNOW Foods, Inc. P. Lapuerta: Employee; Self; Lexicon Pharmaceuticals, Inc.. Stock/Shareholder; Self; Lexicon Pharmaceuticals, Inc., Merck & Co., Inc. D.K. McGuire: Consultant; Self; AstraZeneca, Sanofi-Aventis, Eli Lilly and Company, Boehringer Ingelheim Pharmaceuticals, Inc., Merck & Co., Inc., Pfizer Inc., Novo Nordisk A/S. Research Support; Self; AstraZeneca, Sanofi-Aventis, Janssen Pharmaceuticals, Inc., Boehringer Ingelheim Pharmaceuticals, Inc., Merck & Co., Inc., Novo Nordisk A/S, Lexicon Pharmaceuticals, Inc., Eisai Inc., GlaxoSmithKline plc., Esperion Therapeutics. A.L. Peters: Advisory Panel; Self; Abbott, Bigfoot Biomedical. Research Support; Self; Dexcom, Inc.. Advisory Panel; Self; Eli Lilly and Company, Insulin Algorithms, JDRF, Lexicon Pharmaceuticals, Inc., Livongo Health. Research Support; Self; MannKind Corporation. Other Relationship; Self; Medscape. Advisory Panel; Self; Merck & Co., Inc.. Research Support; Self; National Institute of Diabetes and Digestive and Kidney Diseases. Speaker9s Bureau; Self; Novo Nordisk Inc.. Advisory Panel; Self; Novo Nordisk Inc., Omada Health, Inc., Optum Rx, Inc., Sanofi. Research Support; Self; T1D Exchange. Advisory Panel; Self; The Endocrine Society. Research Support; Self; The Leona M. and Harry B. Helmsley Charitable Trust. Advisory Panel; Spouse/Partner; Johnson & Johnson Diabetes Institute, LLC. S. Sawhney: Employee; Self; Lexicon Pharmaceuticals, Inc.. Stock/Shareholder; Spouse/Partner; GlaxoSmithKline plc., AstraZeneca, Pfizer Inc., Eli Lilly and Company, Novartis Pharmaceuticals Corporation. P. Strumph: Employee; Self; Lexicon Pharmaceuticals, Inc.. Stock/Shareholder; Self; Lexicon Pharmaceuticals, Inc.. Board Member; Self; College Diabetes Network.