Home Testing of Day and Night Closed Loop With Pump Suspend Feature

The main study objective is to determine whether day and night automated closed loop glucose control combined with pump suspend feature will improve glucose control and reduce the burden of hypoglycaemia compared to sensor augmented insulin pump therapy alone. This is an open-label, multi-centre, multi-national, single-period, randomised, parallel group design study, involving a three-month period of home study during which day and night glucose levels will be controlled either by a closed loop system combined with pump suspend feature (intervention group) or by sensor augmented insulin pump therapy (control group). It is expected that up to 100 subjects, aiming for 84 randomised subjects \[42 youth (6 to 21 years), and 42 adults (22 years and older)\], with type 1 diabetes will be recruited through paediatric and adult outpatient diabetes clinics in each of the investigation centres. Subjects who drop out within the first four weeks of the intervention may be replaced. Participants will all be on subcutaneous insulin pump therapy and will have proven competencies both in the use of the study insulin pump and the study CGM device. Subjects in the intervention group will receive appropriate training in the safe use of closed loop insulin delivery system and pump suspend feature. All subjects will have regular contact with the study team during the home study phase including 24/7 telephone support. The primary outcome is between group differences in the time spent in the target glucose range from 3.9 to 10.0 mmol/l (70 to 180mg/dl) based on CGM glucose levels during the 12 week free living phase. Secondary outcomes are HbA1 at the end of treatment period, the time spent with glucose levels above and below target, as recorded by CGM, and other CGM-based metrics. Safety evaluation comprises assessment of the frequency of severe hypoglycaemic episodes.