Randomized Trial of the Insulin-Only iLet Bionic Pancreas for the Treatment of Cystic Fibrosis-Related Diabetes

Objective: Cystic fibrosis-related diabetes (CFRD) affects up to 50% of adults with cystic fibrosis and adds significant morbidity and treatment burden. We evaluated the safety and efficacy of automated insulin delivery with the iLet® bionic pancreas (BP) in adults with CFRD in a single-center, open-label, random-order cross-over trial (NCT #03258853).

Research Design and Methods: Twenty participants with CFRD were assigned in random-order to 14-days each on the BP or their usual diabetes care (UC). No restrictions were placed on diet or activity. The primary outcome was the percent time sensor-measured glucose was in target range 70–180 mg/dL (TIR) on days 3-14 of each arm, and key secondary outcomes included mean CGM glucose and the percent time sensor-measured glucose was in hypoglycemic range <54 mg/dL.

Results: TIR was significantly higher in the BP arm compared to the UC arm (75±11 versus 62±22%, p=0.001). Mean CGM glucose was lower in the BP arm than in the UC arm (150±19 mg/dL versus 171±45 mg/dL, p=0.007). There was no significant difference in percent time with sensor-measured glucose <54 mg/dL (0.27% versus 0.36%, p=1.0), although self-reported symptomatic hypoglycemia episodes were higher during the BP arm than the UC arm (0.7 vs 0.4 median episodes per day, p=0.01). No episodes of diabetic ketoacidosis or severe hypoglycemia occurred in either arm.

Conclusions: Adults with CFRD had improved glucose control without an increase in CGM-measured hypoglycemia with the BP compared to their UC, suggesting this may be an important therapeutic option for this patient population.