Closing the Loop in Adults With Type 1 Diabetes Under Free Living Conditions (AP@Home04_Phase 4)

Purpose of clinical trial The purpose is to determine whether home use of day and night closed loop applying ultra-rapid insulin lispro is superior to home use of closed loop applying standard insulin lispro.

Study objectives The study objective is to compare day and night automated closed-loop glucose control using ultra-rapid insulin lispro with closed loop control using standard insulin lispro.

EFFICACY: The objective is to assess the efficacy of day and night automated closed-loop glucose control applying standard insulin lispro in maintaining CGM glucose levels within the target range from 3.9 to 10.0 mmol/l, as compared to day and night closed-loop using ultra-rapid acting insulin lispro.

SAFETY: The objective is to evaluate the safety of day and night automated closed-loop glucose control in terms of episodes of severe hypoglycaemia, hyperglycaemia and other adverse events and adverse device effects.

UTILITY: The objective is to determine the percentage of time when closed-loop was operational, and usability and acceptance of the closed-loop system.

Study Design A double-blind, single-centre, randomised, two-period crossover study, contrasting day and night automated closed-loop glucose control applying standard insulin lispro with day and night closed-loop control applying ultra-rapid acting insulin lispro.

Study Efficacy Endpoints The primary outcome is the time spent in the target glucose range from 3.9 to 10.0 mmol/l based on CGM glucose levels during the free living phase.

Secondary outcomes include time spent above and below the target glucose range, based on CGM levels.

Safety Evaluation Frequency of severe hypoglycaemic episodes as defined by American Diabetes Association, frequency of severe hyperglycaemia (>20 mmol/L) and / or significant ketosis (plasma ketones >3mmol/l) and nature and severity of other adverse events.

Utility Evaluation Percentage of time spent in closed-loop. Usability and acceptance of the closed-loop system will be assessed using a patient experience questionnaire at the end of the second intervention. Additionally, human factor questionnaires will be administered following recruitment and at the end of each intervention arm.

Sample Size 24 adults completing the study. Up to 30 subjects will be recruited to allow for dropouts.

Maximum duration of study for a subject 20 weeks (5 months)

Recruitment The subjects will be recruited through the adult diabetes outpatient clinics or other established methods at the participating centre.

Consent Participants will be asked to provide written informed consent.

Baseline Assessment Eligible subjects will undergo a baseline evaluation including a blood sample for the measurement of HbA1c, renal, liver function, full blood count, thyroid function and coeliac antibody screen (if not done in the previous 3 months). Urine pregnancy test will be done in females. Human factor questionnaires will be administered.

Study Training and Run-in Period Training sessions on the use of study CGM, insulin pump and closed-loop system will be provided by the research team. During the 2-4 weeks run-in period, subjects will use study CGM and insulin pump and will have regular contact with the research team. At the end of the run-in period, for compliance and to assess the ability of the subject to use the CGM and study pump safely, before the start of the first home study phase, at least 7 days of CGM data need to be recorded and safe use of study insulin pump demonstrated. CGM and insulin pump data during the run-in period will be used to assess baseline glucose control and optimise treatment before the start of the first home study phase.

Competency Assessment Competency on the use of study insulin pump, study CGM and closed-loop system will be evaluated using a competency assessment tool developed by the research team. Further training may be delivered as required.

Randomisation Eligible subjects will be randomised using randomisation software to the initial use of closed-loop with ultra-rapid insulin lispro followed by closed-loop with standard insulin lispro or the alternate order.

Automated closed-loop Training on the use of closed-loop will be provided by the research team. Automated closed-loop control will be commenced and during the training; the participant will operate the system under the supervision of the clinical team. Competency on the use of closed-loop system will be evaluated. Subjects will be advised to use automated closed-loop system for next 8 weeks

Cross-over Assessment At the end of the first intervention human factor questionnaires will be administered.

There will be no washout period in phase 4 extension.

End of study assessments A patient experience questionnaire will be given at the end of the second intervention. Additionally human factor questionnaires will be administered.

Procedures for safety monitoring during trial Standard operating procedures for monitoring and reporting of all adverse events and adverse device events will be in place, including serious adverse events (SAE), serious adverse device effects (SADE) and specific adverse events (AE) such as severe hypoglycaemia.

Criteria for withdrawal of patients on safety grounds

A subject may terminate participation in the study at any time without necessarily giving a reason and without any personal disadvantage. An investigator can stop the participation of a subject after consideration of the benefit/risk ratio. Possible reasons are:

Serious adverse events Significant protocol violation or noncompliance Failure to satisfy competency assessment Decision by the investigator, or the sponsor, that termination is in the subject's best medical interest Pregnancy, planned pregnancy, or breast feeding Allergic reaction to insulin Technical grounds (e.g. subject relocates)