Closing the Loop in Adults With Type 1 Diabetes (CLEAR)

The main objective of this study is to determine whether home use of fully closed-loop glucose control applying ultra-rapid Lispro insulin is superior to standard insulin pump therapy with continuous glucose monitoring (CGM) in adults with type 1 diabetes on insulin pump therapy with sub-optimal glycaemic control (HbA1c ≥ 8.0%). This is an open-label, single centre, randomised, crossover design study, involving a run-in period followed by two study periods during which glucose levels will be controlled either by an automated closed-loop system using ultra-rapid Lispro insulin or by participants usual insulin pump therapy with continuous glucose monitoring in random order. A total of up to 30 adults (aiming for 24 completed participants) with T1D on insulin pump therapy will be recruited through diabetes clinics and other established methods. Participants who drop out of the study within the first 4 weeks of the first intervention arm will be replaced. Participants will receive appropriate training in the safe use of the closed-loop devices. Participants will have access to the study team during the home study phase with 24/7 telephone support. The primary outcome is time spent in target range between 3.9 and 10.0 mmol/L as recorded by CGM over the 8 week period. Secondary outcomes are HbA1c, time spent with glucose levels above and below target as recorded by CGM, and other CGM-based metrics in addition to insulin requirements. Safety evaluation comprises severe hypoglycaemic episodes, diabetic ketoacidosis (DKA) events and other adverse and serious adverse events.