The bionic pancreas (BP) continues to make all insulin dosing decisions autonomously when continuous glucose monitoring (CGM) data is not available. Basal insulin is given based on a profile determined autonomously by the BP when CGM data was available. Meals are announced as Breakfast, Lunch, or Dinner and by relative size (Usual, Less, More) ; insulin dosing is based on adaptation that occurred when CGM data was available. Insulin may be delivered, or temporarily suspended, autonomously by the BP in response to entered blood glucose (BG) values. At the end of the 13-week Pivotal RCT of the BP in type 1 diabetes, participants in the BP group could participate in a study testing the BP without CGM input. Unblinded CGM was replaced by blinded CGM not connected to the BP for ∼49.5 hours. Participants were to enter fingerstick BG values every ∼2 hours during the day and once overnight. Adherence with BG entry requirements by the 54 participants (aged 7-70) was high. There was no severe hypoglycemia or DKA. The frequency of CGM-measured hypoglycemia was similar during the BG Period to the RCT and Pre-Randomization periods. Hyperglycemia metrics were nominally higher during the BG Period than the RCT, but nominally lower than the Pre-randomization Baseline period. The BP can autonomously determine all insulin doses and achieve safe glucose control without CGM input when intermittent BG values are provided by the user.


C. A. Balliro: Consultant; Beta Bionics, Inc., Zealand Pharma A/S.


Funding from National Institute of Diabetes and Digestive and Kidney Diseases (#1UC4DK108612-01) . Funding and bionic pancreas devices from Beta Bionics, Inc. Fast-acting insulin aspart and insulin aspart provided by Novo Nordisk Insulin lispro by Eli LillyBlood glucose meters and test strips (Contour Next One Blood Glucose Monitoring System) provided by Ascensia Diabetes Care, Basel, CH. Continuous glucose monitor sensors and transmitters were purchased from Dexcom, Inc. at a discounted price.

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