Dual Hormone Closed Loop in Type 1 Diabetes

Rationale: Patients with type 1 diabetes mellitus (T1DM) require lifelong insulin therapy. Insulin therapy improves but does not fully normalise blood glucose levels with current therapies. Current therapies include subcutaneous insulin injection or subcutaneous insulin infusion, combined with a device to measure glucose levels (finger stick, intermittent sensor or continuous glucose monitoring). Although having provided a huge improvement in glycaemic control, patients have to work hard every day and still have to calculate mealtime boluses. An automated insulin delivery device covering both basal and prandial insulin requirement would mean another great leap forwards. The dual-hormone fully closed loop (DHFCL) provides such a new strategy of automated insulin delivery coupled with targeted glucagon infusion as insulin-antagonist to even more approximate normal physiology. Objective: To determine the long-term clinical effectiveness of treatment with a dual-hormone (insulin and glucagon) fully closed loop system during 12 months compared to the current most used care and to the currently most advanced technological care. Secondary objectives include the assessment of cost-effectiveness, Patient Reported Outcome Measures (PROMs), other glycaemic outcomes and safety. Study design: A 12 month open-label, two-arm randomised parallel-group trial. Study population: Adult (age ≥18 years) patients with T1DM for at least 1 year with an HbA1c at entry ≤ 91 mmol/mol. Intervention: The study includes two separately randomised arms, defined by current diabetes treatment. In one arm, patients currently on Multiple Daily Injections (MDI; at least once daily long-acting insulin and thrice daily short-acting insulin) in combination with continuous or flash glucose monitoring (CGM or FGM; currently the most used strategy) are 1:1 randomised to either the intervention, i.e. the DHFCL, or continuation of their current treatment. In the other arm, patients currently on hybrid closed loop treatment (HCL; presently the most advanced diabetes control treatment) are 1:1 randomised to either the intervention or continuation of their current care. Main study parameters/endpoints: The main study endpoint is the Time in Range (TIR; % of time spent in the 3.9-10 mmol/l target range) at 12 months, which will be compared between the intervention and the control treatment within each arm. Secondary endpoints include cost-effectiveness, PROMs, other glycaemic outcomes, safety measures and device-related outcomes.