The Insulin-Only Bionic Pancreas Pivotal Trial Extension Study: A Multi-Center Single-Arm Evaluation of the Insulin-Only Configuration of the Bionic Pancreas in Adults and Youth with Type 1 Diabetes

Objective: To evaluate a transition from standard-of-care (SC) management of type 1 diabetes (any insulin delivery method including hybrid closed-loop systems plus real-time continuous glucose monitoring [CGM]) to use of the insulin-only configuration of the iLet® bionic pancreas (BP) in 90 adults and children (age 6-71 years). Research Design and Methods: After the SC group completed the randomized controlled trial (RCT) portion of the Insulin-Only BP Pivotal Trial, 90 of the 107 participants participated in a 13-week study using the BP. The key outcomes were change from baseline in HbA1c and CGM metrics after 13 weeks on the BP. Results: Using the BP, mean HbA1c decreased from 7.7% ± 1.0% (61 ± 10.9 mmol/mol) at baseline to 7.1% ± 0.6% (54 ± 6.6 mmol/mol) at 13 weeks (mean change-0.55% ± 0.72% [-6 ± 7.9 mmol/mol], P < 0.001), time in range 70-180 mg/dL increased by 12.0% ± 12.5% (from 53% ± 17% to 65% ± 9%, P < 0.001), and mean glucose decreased by-18 ± 23 mg/dL (from 182 ± 32 to 164 ± 15 mg/dL, P < 0.001). The higher the baseline HbA1c level, the greater the change in HbA1c. Results were similar in the adult (N = 42) and pediatric (N = 48) cohorts. Time <70 mg/dL decreased from baseline over the 13 weeks by-0.50% ± 1.86% (P = 0.02), and time <54 mg/dL was similar (change from baseline-0.08% ± 0.59%, P = 0.24). Two severe hypoglycemia events (in same participant) and one diabetic ketoacidosis event occurred. Conclusions: Glycemic control improved after adult and pediatric participants in the SC arm in the Insulin-Only BP Pivotal Trial transitioned to use of the BP. Improvement using the BP was of similar magnitude to that observed during the RCT. ClinicalTrials.gov number, NCT04200313.