Safety and glycemic outcomes during the MiniMed™ Advanced Hybrid Closed-Loop system pivotal trial in adolescents and adults with type 1 diabetes.

INTRODUCTION: This trial assessed safety and effectiveness of an advanced hybrid closed-loop (AHCL) system with automated basal (Auto Basal) and automated bolus correction (Auto Correction) in adolescents and adults with type 1 diabetes (T1D).

MATERIALS AND METHODS: This multi-center, single-arm study involved an intent to treat population of 157 individuals (39 adolescents aged 14-21 years and 118 adults aged ≥22-75 years) with T1D. Study participants used the MiniMed™ AHCL system during a baseline run-in period in which sensor-augmented pump +/- predictive low glucose management or Auto Basal was enabled for ~14 days. Thereafter, Auto Basal and Auto Correction were enabled for a study phase (~90 days), with glucose target set to 100mg/dL or 120mg/dL for ~45 days, followed by the other target for ~45 days. Study endpoints included safety events and change in mean A1C, time in range (TIR, 70-180mg/dL) and time below range (TBR, <70mg/dL). Run-in and study phase values were compared using Wilcoxon signed-rank testa or paired t-test.

RESULTS: Overall group time spent in closed loop averaged 94.9±5.4% and involved only 1.2±0.8 exits/week. Compared to run-in, AHCL reduced A1C from 7.5±0.8% to 7.0±0.5% (<0.001a, N=155), TIR increased from 68.8±10.5% to 74.5±6.9% (<0.001a) and TBR reduced from 3.3±2.9% to 2.3±1.7% (<0.001a ). Similar benefits to glycemia were observed for each age group, and were more pronounced for the nighttime (12AM-6AM). The 100mg/dL target increased TIR to 75.4% (N=155), that was further optimized at a lower active insulin time setting (i.e. 2 hours), without increasing TBR. There were no severe hypoglycemia or diabetic ketoacidosis events during the study phase.

CONCLUSIONS: These findings indicate that the MiniMed™ AHCL system is safe and allows for achievement of good glycemic targets in adolescents and adults with T1D. Adjustments in target and active insulin time settings may further optimize glycemia and improve user experience.