Trial results for a Hybrid Closed Loop (HCL) system in adult and pediatric patients with Type 1 Diabetes were posted on ClinicalTrials.gov on 2025-08-19. The study, which evaluated the system's safety and effectiveness in a home setting, enrolled 959 participants.
Background
Type 1 Diabetes is a chronic autoimmune condition requiring lifelong insulin management to maintain blood glucose levels within a target range. Current treatment regimens often involve multiple daily injections (MDI), continuous subcutaneous insulin infusion (CSII), or sensor-augmented pump (SAP) therapy. Despite these advancements, achieving optimal glycemic control while minimizing the risk of hypoglycemia remains a significant challenge for many patients. Hybrid Closed Loop systems aim to automate insulin delivery, potentially improving glycemic outcomes and reducing the burden of diabetes management.
Trial design
This completed study, designated as Phase NA, investigated the Hybrid Closed Loop system in 959 adult and pediatric patients with Type 1 Diabetes. The trial aimed to evaluate the safety and effectiveness of the HCL system in the home setting across a diverse population, including those previously on MDI, CSII, or SAP therapy. Participants were categorized into cohorts based on their prior insulin delivery method and baseline A1C levels, with comparisons made between a treatment arm using the HCL system and a control arm representing standard care within each cohort.
Key results
The trial reported key measurements and analyses across different patient cohorts:
- CSII Cohort: Baseline A1C > 8%: Change in A1C (∆A1C)
- Treatment Arm: Mean change of -1.6 (Standard Deviation 1.3) Percentage of HbA1c.
- Control Arm: Mean change of -0.8 (Standard Deviation 0.9) Percentage of HbA1c.
- CSII Cohort: Baseline A1C ≤ 8%: Time in Hypoglycemic Range
- Treatment Arm: Mean time of 2.4 (Standard Deviation 1.9) Percentage of Time.
- Control Arm: Mean time of 7.3 (Standard Deviation 5.3) Percentage of Time.
- MDI Cohort: Baseline A1C > 8%: Change of A1C (∆A1C)
- Treatment Arm: Mean change of -1.4 (Standard Deviation 1.1) Percentage of HbA1c.
- Control Arm: Mean change of -0.6 (Standard Deviation 0.9) Percentage of HbA1c.
- MDI Cohort: Baseline A1C ≤ 8%: Time in Hypoglycemic Range
- Treatment Arm: Mean time of 2.8 (Standard Deviation 2.7) Percentage of Time.
- Control Arm: Mean time of 7.5 (Standard Deviation 6.1) Percentage of Time.
- SAP Cohort: Baseline A1C > 8%: Change of A1C (∆A1C)
- Treatment Arm: Mean change of -0.6 (Standard Deviation 0.8) Percentage of HbA1c.
- Control Arm: Mean change of -0.6 (Standard Deviation 1.0) Percentage of HbA1c.
- SAP Cohort: Baseline A1C ≤ 8%: Time in Hypoglycemic Range
- Treatment Arm: Mean time of 2.5 (Standard Deviation 2.3) Percentage of Time.
- Control Arm: Mean time of 3.5 (Standard Deviation 3.0) Percentage of Time.
Key analyses of mean differences (final values) between treatment and control arms included:
- For CSII Cohort with Baseline A1C > 8% (A1C): Mean Difference of -0.8 (97.5% CI Upper: -0.4).
- For CSII Cohort with Baseline A1C ≤ 8% (Hypoglycemia): Mean Difference of -4.9 (97.5% CI Upper: -3.6).
- For MDI Cohort with Baseline A1C > 8% (A1C): Mean Difference of -0.7 (97.5% CI Upper: -0.3).
- For MDI Cohort with Baseline A1C ≤ 8% (Hypoglycemia): Mean Difference of -4.8 (97.5% CI Upper: -3.1).
- For SAP Cohort with Baseline A1C > 8% (A1C): Mean Difference of 0.0 (97.5% CI Upper: 0.3).
- For SAP Cohort with Baseline A1C ≤ 8% (Hypoglycemia): Mean Difference of -1.0 (97.5% CI Upper: -0.2).
What this means
The results indicate that the Hybrid Closed Loop system generally improved glycemic control and reduced hypoglycemia in Type 1 Diabetes patients. Notably, in the CSII cohort with baseline A1C > 8%, the HCL system led to a substantial mean A1C reduction of -1.6%, compared to -0.8% in the control arm. Similarly, for both CSII and MDI cohorts with baseline A1C ≤ 8%, the HCL system significantly reduced time in hypoglycemia, with mean differences of -4.9% and -4.8% respectively, compared to control. While the A1C improvement was less pronounced in the SAP cohort, the HCL system still demonstrated a reduction in hypoglycemic time for this group. These findings suggest that the HCL system can be an effective tool for improving glycemic management and safety across various Type 1 Diabetes patient populations, particularly those with higher baseline A1C or those currently on MDI or CSII regimens.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT02748018, titled "Multi-center Trial in Adult and Pediatric Patients With Type 1 Diabetes Using Hybrid Closed Loop System and Control at Home", were posted on 2025-08-19 on clinicaltrials.gov.