Performance of the Insulin-Only iLet Bionic Pancreas and the Bihormonal iLet Using Dasiglucagon in Adults With Type 1 Diabetes in a Home-Use Setting

Abstract

Reductions in blood glucose levels in people with diabetes are often achieved at the expense of increased hypoglycemia. A novel approach is to automatically deliver microdose glucagon when automation of insulin delivery alone is not sufficient to prevent hypoglycemia. The approach requires a bihormonal device and a stable form of glucagon or glucagon analog. The iLet bionic pancreas (Beta Bionics, Inc.) is a purpose-built, fully integrated device that receives a signal from a continuous glucose monitor (CGM) and contains autonomous, lifelong learning, mathematical dosing algorithms, which are initialized only with the patient’s body weight (1). We evaluated the function and safety of the iLet in both its insulin-only configuration and its bihormonal configuration delivering dasiglucagon, a chemically stable glucagon analog (Zealand Pharma), in a home-use study in adults with type 1 diabetes (T1D). This open-label, random-order, crossover, home-use trial (clinical trial reg. no. NCT03840278, ClinicalTrials.gov) was the first human study to test the bihormonal iLet configuration and the first multiday use of dasiglucagon in people with T1D (2). Ten participants used the insulin-only iLet for 7 days with insulin lispro (Eli Lilly) or aspart (Novo Nordisk), the bihormonal iLet for 7 days with dasiglucagon (4 mg/mL) and insulin lispro or aspart, or both, using the same glucose target (110 mg/dL), in random order. There were no restrictions on diet or exercise. The primary outcomes were prespecified iLet operational thresholds. The key secondary outcome was the median time with CGM glucose <54 mg/dL on days 2–7 (after one day of adaptation). All participants completed the study. …

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