928-P: AI-Based Fully Closed Loop (FCL) Achieves Improved Glycemia vs. Hybrid Closed Loop (HCL) in People with Type 1 Diabetes (T1D)

Introduction and Objective: HCL is the preferred insulin delivery method for people with T1D, however mealtime carbohydrate counting limits benefit. Use of AI to implement automated insulin delivery (AID) algorithms, able to avoid mealtime interactions, could alleviate burden and broaden use. We tested the latest UVA AID neural network-based system (AIDANET) in FCL in a people with T1D. Methods: Adults (>25 y, n=12), young adults (18-25 y, n=10), and adolescents (14-17 y, n=12) were enrolled at three sites to compare AIDANET in FCL to usual care in HCL (NCT06041917). Participants spent 5 days using FCL in a supervised hotel environment followed by 7 days of at-home use. Usual care data was collected randomly for two weeks before or after FCL use. The prespecified primary outcome was difference in mean CGM. Results: Overall, 34 participants (25.4±12.6 y, 62% F, HbA1c 8.0±1.1%) completed the study. Mean CGM significantly improved from 177.9 mg/dL with HCL to 163.8 mg/dL with FCL (-14.1 mg/dL; p=0.013; Table). TIR, TITR, TAR>180, and TAR>250 also significantly improved. TBR<70 and TBR<54 were non-inferior in FCL vs HCL. CV increased in FCL vs HCL but SD did not. Daily meal boluses decreased from 4.0±2.6 to 0.0±0.0 (p<0.001). Conclusion: Fully closed loop therapy with the AIDANET system can significantly improve average glycemia while removing the need for mealtime bolusing for people with T1D. Disclosure G.P. Forlenza: Advisory Panel; Medtronic. Research Support; Medtronic, Dexcom, Inc. Consultant; Dexcom, Inc. Research Support; Insulet Corporation. Consultant; Insulet Corporation. Research Support; Tandem Diabetes Care, Inc. Advisory Panel; Tandem Diabetes Care, Inc. Research Support; Abbott. Advisory Panel; Sequel Med Tech. M. Moscoso-Vasquez: Other Relationship; Dexcom, Inc. Research Support; Tandem Diabetes Care, Inc, National Institute of Diabetes and Digestive and Kidney Diseases. S.A. Brown: Research Support; Dexcom, Inc., Insulet Corporation, Tandem Diabetes Care, Inc, Tolerion, Roche Diabetes Care. Other Relationship; MannKind Corporation. G. Capodanno: None. E. Cengiz: Advisory Panel; Novo Nordisk, Arecor Therapeutics, Eli Lilly and Company, Tandem Diabetes Care, Inc, Portal Insulin, MannKind Corporation. E.C. Cobry: Advisory Panel; Dexcom, Inc. M.D. DeBoer: Research Support; Dexcom, Inc., Tandem Diabetes Care, Inc, Medtronic. R. Wadwa: Consultant; Dexcom, Inc., Tandem Diabetes Care, Inc. Advisory Panel; Provention Bio, Inc, Provention Bio, Inc, Microbion, Microbion, Sequel Med Tech. Research Support; Dexcom, Inc., Eli Lilly and Company, Tandem Diabetes Care, Inc. J.C. Wong: Research Support; Abbott, Dexcom, Inc., Tandem Diabetes Care, Inc. L. Ekhlaspour: Other Relationship; Medtronic. Advisory Panel; Abbott, Medtronic. Consultant; Jaeb Center for Health Research. Research Support; MannKind Corporation. Speaker's Bureau; Insulet Corporation. Advisory Panel; Sequel Med Tech. Other Relationship; Tandem Diabetes Care, Inc. Research Support; Abbott. Other Relationship; Sanofi. M.D. Breton: Speaker's Bureau; Sinocare Inc, Tandem Diabetes Care, Inc. Consultant; Roche Diabetes Care, Boydsense. Funding Breakthrough T1D (2-SRA-2023-1275-M-B)