The continuation phase of the LENNY randomized trial evaluated a hybrid closed-loop insulin delivery system in young children aged 2–6 years with T1D. Published in Diabetes Research and Clinical Practice, the study examined long-term performance of the system when used with two types of CGM sensors.

Ninety-one participants completed a 12–24-week period using the system with a real-time CGM sensor in automated mode. They were then randomized to either continue with the same sensor or switch to a factory-calibrated next-generation CGM sensor for an additional 12 weeks.

After the treatment period, mean ± SD glycated hemoglobin (HbA1c) was 7.24 ± 0.64 % for the real-time CGM group and 7.30 ± 0.53 % for the factory-calibrated CGM group. TIR was similar between the two groups (68.9 ± 8.6 % versus 69.7 ± 7.7 %), confirming non-inferiority for both glycemic outcomes.

The findings demonstrate that hybrid closed-loop insulin therapy maintains stable glycemic control and safety during long-term use in young children. Switching between CGM sensors did not affect performance, supporting the continued use of automated insulin delivery systems as a reliable approach to optimize diabetes management in this population.