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type1.science
N/A (device / behavioral)CompletedNCT04200313

iLet Bionic Pancreas (insulin-only) pivotal trial

What this study tests

The main 13-week randomized comparison included 326 adults and children with T1D: 219 using iLet with aspart/lispro and 107 using standard care. HbA1c improved and CGM time below 54 mg/dL met the noninferiority criterion. The registry’s total of 440 includes a separate faster-aspart group; it is not the denominator for the headline comparison.

Editorial review: .

Registry checked: 2026-09-17. Registry’s own update: 2025-02-20.

Most recent recorded citation date: 2022-10-01. Only explicit date metadata is included; an undated citation may be newer. This does not mean every claim was reviewed on that date.

Trial status, labels and access can change between reviews. How we review the evidence · How to read the evidence

Full sources ↓Full discussion ↓Report an issue →

Evidence at a glance

Who can enter the study?
Adults and children at least 6 years old with type 1 diabetes (in the main analysis, ages 6 to 79). Participants used any baseline insulin-delivery method (multiple daily injections, insulin pump, or a hybrid closed-loop system). The standard-care comparison group used their own insulin-delivery method plus unblinded real-time continuous glucose monitoring. Registered eligibility ↗Enrollment criteria describe who may enter. They do not establish who was analyzed or the denominator for a reported result.
Reported benefit and results
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.Read the result sources and their limitations →
Important harms
Read the reported results, safety discussion and original sources. A separate harms summary is not available; this does not establish safety.
Research access and approval
Study regions: United States. A trial listing does not establish product approval or current recruitment at a particular site. Check the study’s current entry requirements.
What remains uncertain?
Read the full discussion and original sources for study limitations. Planned endpoints and completion dates are not results.

Research status alone does not establish approval, clinical benefit or local availability.

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)

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.1

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.2 The registry lists 440 participants across the broader protocol, including a separate faster-aspart group. In the published main comparison of 326 participants, 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).1 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).1

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).1 In the company-reported topline, users also gained roughly 2.6 more hours per day in the target glucose range.3 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.1 A companion analysis of the 165 youth aged 6–17 in this main trial showed the same pattern, with the biggest gains in those who started with the highest HbA1c.4

What it means and what's next. The trial showed improved glycemic control with a simpler meal-input approach in the studied population, and the iLet was cleared in May 2023 for people aged 6 and older with type 1 diabetes, as announced by Boston University.5 The announcement described the system as commercially available, lowering the day-to-day math required to manage type 1 diabetes.5

Sources

  1. [1]
    Multicenter, Randomized Trial of a Bionic Pancreas in Type 1 Diabetes. · Peer-reviewed study · 2022-09-01

    Bionic Pancreas Research Group. Multicenter, Randomized Trial of a Bionic Pancreas in Type 1 Diabetes. New England Journal of Medicine (2022).

    Bionic Pancreas Research Group. Multicenter, Randomized Trial of a Bionic Pancreas in Type 1 Diabetes. New England Journal of Medicine 2022;387:1161-1172.

  2. [2]
    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) · Trial registry

    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).

  3. [3]
    Beta Bionics. The iLet Bionic Pancreas Significantly Reduced HbA1c and Improved Time in Range vs Standard of Care. *Healio / Beta Bionics press release* (2022) · Science journalism

    Beta Bionics. The iLet Bionic Pancreas Significantly Reduced HbA1c and Improved Time in Range vs Standard of Care. Healio / Beta Bionics press release (2022).

  4. [4]
    Positive Impact of the Bionic Pancreas on Diabetes Control in Youth 6-17 Years Old with Type 1 Diabetes: A Multicenter Randomized Trial. · Peer-reviewed study · 2022-10-01

    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).

  5. [5]
    Boston University. FDA Clears Bionic Pancreas Developed in BU Lab for People with Type 1 Diabetes. *BU News* (2023) · Open-source community

    Boston University. FDA Clears Bionic Pancreas Developed in BU Lab for People with Type 1 Diabetes. BU News (2023).