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type1.science
Phase 3CompletedNCT04200313

iLet Bionic Pancreas (insulin-only) pivotal trial

Landmark pivotal randomized trial of the Beta Bionics iLet — an automated insulin-delivery system that needs no carb counting (meal announcements only) and is initialized from body weight alone. Over 13 weeks in 440 adults and children, it lowered HbA1c versus standard care without raising hypoglycemia, providing the basis for FDA clearance in 2023.

Primary endpoints

  • Glycated hemoglobin (HbA1c) level at 13 weeks
  • Key secondary (safety): percentage of CGM time below 54 mg/dL at 13 weeks, tested for noninferiority (prespecified limit 1 percentage point)

Results so far

Over 13 weeks, HbA1c fell from 7.9% to 7.3% with the bionic pancreas and stayed at 7.7% with standard care (adjusted difference -0.5 percentage points; 95% CI -0.6 to -0.3; P<0.001). Time in range (70-180 mg/dL) rose by the equivalent of about 2.6 hours more per day. Low-glucose exposure (CGM time below 54 mg/dL) was noninferior to standard care (adjusted difference 0.0 percentage points; P<0.001 for noninferiority). Severe hypoglycemia rates did not differ significantly (17.7 vs 10.8 events per 100 participant-years; P=0.39), and no diabetic ketoacidosis occurred in either group. Benefits were largest in people who started with the highest HbA1c, and were similar across adult and pediatric cohorts and across racial/ethnic groups.

The full picture

What is being tested and why it matters. Most automated insulin-delivery systems still ask a lot of the user: they need preset insulin doses to start and they count the carbohydrates in every meal. The iLet bionic pancreas takes a different approach — it is set up using only the person's body weight, then makes and delivers every insulin dose on its own, and for meals you simply announce a meal qualitatively (for example "breakfast," and whether it is usual, more, or less) instead of counting carbs.1 This pivotal trial tested whether that simpler, lower-burden system could safely improve blood-sugar control.1

Who it's for. The trial enrolled adults and children at least 6 years old with type 1 diabetes (the published analysis ranged from 6 to 79 years), regardless of whether they previously used injections, a pump, or an automated system.2

Design. This was a 13-week, multicenter, randomized controlled trial run at 16 U.S. sites, sponsored by the Jaeb Center for Health Research with funding from the NIDDK.3 In total 440 participants were enrolled; in the main comparison, people were randomly assigned in a 2:1 ratio to the bionic pancreas (219 participants) or to standard care — their own insulin-delivery method plus real-time continuous glucose monitoring (107 participants).2 The main goal was HbA1c (a marker of average blood sugar) at 13 weeks; the key safety goal was time spent with dangerously low glucose (below 54 mg/dL).2

Key results. HbA1c dropped from 7.9% to 7.3% with the bionic pancreas but did not change (7.7%) with standard care — an adjusted difference of -0.5 percentage points (95% CI -0.6 to -0.3; P<0.001).2 Users also gained roughly 2.6 more hours per day in the target glucose range.4 Importantly, this came without more low-glucose exposure: time below 54 mg/dL was noninferior to standard care (P<0.001 for noninferiority), severe hypoglycemia rates did not differ significantly (P=0.39), and no diabetic ketoacidosis occurred in either group.2 A companion trial in 165 youth aged 6-17 showed the same pattern, with the biggest gains in those who started with the highest HbA1c.5

What it means and what's next. The trial showed a simpler, carb-counting-free system can improve control safely across a wide age range, and it became the basis for FDA clearance: the iLet was cleared in May 2023 for people aged 6 and older with type 1 diabetes.6 The system is now commercially available, lowering the day-to-day math required to manage type 1 diabetes.6

References

  1. Bionic Pancreas Research Group. Multicenter, Randomized Trial of a Bionic Pancreas in Type 1 Diabetes. New England Journal of Medicine (2022). https://doi.org/10.1056/NEJMoa2205225 ↩ ↩2

  2. Bionic Pancreas Research Group. Multicenter, Randomized Trial of a Bionic Pancreas in Type 1 Diabetes. New England Journal of Medicine 2022;387:1161-1172. https://doi.org/10.1056/NEJMoa2205225 ↩ ↩2 ↩3 ↩4 ↩5

  3. Jaeb Center for Health Research. The Insulin-Only Bionic Pancreas Pivotal Trial: Testing the iLet in Adults and Children With Type 1 Diabetes. ClinicalTrials.gov (NCT04200313). https://clinicaltrials.gov/study/NCT04200313 ↩

  4. Beta Bionics. The iLet Bionic Pancreas Significantly Reduced HbA1c and Improved Time in Range vs Standard of Care. Healio / Beta Bionics press release (2022). https://www.healio.com/news/endocrinology/20220607/bionic-pancreas-reduces-hba1c-improves-time-in-range-in-type-1-diabetes-pivotal-data ↩

  5. Messer LH, et al. Positive Impact of the Bionic Pancreas on Diabetes Control in Youth 6-17 Years Old with Type 1 Diabetes: A Multicenter Randomized Trial. Diabetes Technology & Therapeutics (2022). https://doi.org/10.1089/dia.2022.0201.pub ↩

  6. Boston University. FDA Clears Bionic Pancreas Developed in BU Lab for People with Type 1 Diabetes. BU News (2023). https://www.bu.edu/articles/2023/fda-clears-bionic-pancreas-for-type-1-diabetes/ ↩ ↩2