Control-IQ closed-loop in children 6–13 (DCLP5 pediatric pivotal)
What this study tests
A 16-week, 4-site U.S. randomized trial (n=101) in children aged 6–13 testing the t:slim X2 with Control-IQ automated insulin delivery against a sensor-augmented pump. Time in range rose to 67% with closed-loop vs 55% with control (an 11-point adjusted gain, ~2.6 extra hours/day in range) with no increase in low glucose and no DKA or severe hypoglycemia. These results preceded the FDA's June 2020 expansion of the Control-IQ age indication down to 6 years.
Editorial review: .
Registry checked: 2026-09-17. Registry’s own update: 2023-04-10.
Most recent recorded citation date: 2020-08-01. 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
Evidence at a glance
- Who can enter the study?
- Children 6 to 13 years old with type 1 diabetes for at least 1 year, on insulin for at least 6 months, weighing 25–140 kg, and familiar with counting carbohydrates. Excluded if taking non-insulin glucose-lowering drugs (other than metformin) or enrolled in a conflicting study. Baseline HbA1c ranged from 5.7% to 10.1%, so well- and less-well-controlled children could take part. 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
- Closed-loop improved time in range versus the control therapy over 16 weeks. Time in the 70–180 mg/dL target range rose from 53% at baseline to 67% over 16 weeks with closed-loop, versus 51% to 55% with the sensor-augmented pump — an adjusted difference of 11 percentage points (about 2.6 more hours per day in range; 95% CI 7 to 14; P<0.001). Mean glucose was about 13 mg/dL lower with closed-loop (P<0.001). Time spent low (below 70 mg/dL) stayed low and similar in both groups (median 1.6% vs 1.8%). The system ran in closed-loop mode a median 93% of the time. No diabetic ketoacidosis or severe hypoglycemia occurred in either group. The HbA1c difference (about 0.4 points) was not statistically significant.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. This record cites company or conference reports. Those sources may describe interim findings; their source type is shown in the source list.
Primary endpoints
- Percentage of time the glucose level was in the target range of 70–180 mg/dL (3.9–10.0 mmol/L), measured by continuous glucose monitoring over the 16-week treatment period
The full picture
What this trial tested and why it matters
Automated insulin delivery (AID), sometimes called an "artificial pancreas," links a continuous glucose monitor (CGM) to an insulin pump through software that adjusts insulin automatically every few minutes. When this trial ran, the t:slim X2 pump with Control-IQ technology had just been cleared for people aged 14 and up, but not for younger children.1 This study — part of the International Diabetes Closed-Loop (iDCL) program, known as DCLP5 — asked whether the same system was safe and effective in school-aged children, whose smaller insulin needs, unpredictable eating, and activity make glucose harder to control.2
Who it was for
The trial enrolled 101 children aged 6 to 13 with type 1 diabetes for at least a year.2 Both well-controlled and less-well-controlled children took part — baseline HbA1c ranged from 5.7% to 10.1%.2
How it was designed
This was a 16-week, multicenter, randomized, open-label trial at four U.S. sites (Stanford, the Barbara Davis Center in Colorado, the University of Virginia, and Yale).23 Children were assigned in a 3:1 ratio: 78 to the Control-IQ closed-loop system (t:slim X2 pump plus Dexcom G6 CGM) and 23 to a control group using a sensor-augmented pump.2 The main question was simple: what fraction of the day is glucose kept in the healthy target range of 70–180 mg/dL?2 The University of Virginia led the study, funded by Tandem Diabetes Care and the NIDDK.23
The key results
Closed-loop improved time in range versus control. Time in the 70–180 mg/dL range climbed from 53% to 67% with Control-IQ but barely moved (51% to 55%) in the control group — an adjusted gain of 11 percentage points, roughly 2.6 extra hours per day in range (95% CI 7 to 14; P<0.001).2 Mean glucose fell about 13 mg/dL more with closed-loop.2 This came without more low-glucose time: time below 70 mg/dL was low in both groups (median 1.6% vs 1.8%), and there were no episodes of diabetic ketoacidosis or severe hypoglycemia in either group during the 16 weeks.2 The system ran in closed-loop mode a median 93% of the time.2
What it means and what came next
These results preceded the FDA's June 17, 2020 expansion of the Control-IQ age indication down to 6 years, from clearance only for ages 14 and older, as reported by Breakthrough T1D (JDRF).41 A smaller earlier feasibility study had reported improved time in range with the same system in 6-to-12-year-olds during short home use, paving the way for this larger trial.5 Together, this work helped make automated insulin delivery an available option for school-aged children.
Sources
- [1]Tandem Diabetes Care. FDA Clearance of the t:slim X2 Insulin Pump with Control-IQ Technology. *Tandem Diabetes Care newsroom* (2019) · Manufacturer
Tandem Diabetes Care. FDA Clearance of the t:slim X2 Insulin Pump with Control-IQ Technology. Tandem Diabetes Care newsroom (2019).
- [2]A Randomized Trial of Closed-Loop Control in Children with Type 1 Diabetes. · Peer-reviewed study · 2020-08-01
Breton MD, Kanapka LG, Beck RW, et al. A Randomized Trial of Closed-Loop Control in Children with Type 1 Diabetes. New England Journal of Medicine (2020); 383(9):836–845.
- [3]U.S. National Library of Medicine. The International Diabetes Closed Loop (iDCL) Trial: Clinical Acceptance of the Artificial Pancreas in Pediatrics (NCT03844789). *ClinicalTrials.gov* (2020) · Trial registry
U.S. National Library of Medicine. The International Diabetes Closed Loop (iDCL) Trial: Clinical Acceptance of the Artificial Pancreas in Pediatrics (NCT03844789). ClinicalTrials.gov (2020).
- [4]Breakthrough T1D (JDRF). Tandem Control-IQ — Now Authorized for Children. *Breakthrough T1D news* (2020) · Open-source community
Breakthrough T1D (JDRF). Tandem Control-IQ — Now Authorized for Children. Breakthrough T1D news (2020).
- [5]Successful At-Home Use of the Tandem Control-IQ Artificial Pancreas System in Young Children During a Randomized Controlled Trial. · Peer-reviewed study · 2019-03-19
Forlenza GP, Ekhlaspour L, Breton M, et al. Successful At-Home Use of the Tandem Control-IQ Artificial Pancreas System in Young Children During a Randomized Controlled Trial. Diabetes Technology & Therapeutics (2019); 21(4):159–169.