Cystic fibrosis-related diabetes (CFRD) is one of the most clinically impactful comorbidities associated with cystic fibrosis (CF). Current recommended management with insulin therapy is challenging due to variable daily insulin requirements and adds to the significant burden of self-management. This study aims to determine if hybrid closed-loop insulin delivery can improve glucose outcomes compared with standard insulin therapy with continuous glucose monitoring (CGM) in young people (≥16 years) and adults with CFRD.

This open-label, multicentre, randomised, two-arm, single-period parallel design study aims to randomise 114 young people (≥16 years) and adults with CFRD. Following a 2–3 weeks’ run-in period, during which time participants use a masked CGM, participants with time in target glucose range (3.9–10.0 mmol/L) 10.0 mmol/L), mean glucose and HbA1c. Other secondary efficacy outcomes include glucose and insulin metrics, change in forced expiratory volume in 1 s and body mass index. Safety, utility, participant experiences and participant-reported outcome measures will also be evaluated. The trial is funded by the National Institute for Health and Care Research.

Ethics approval has been obtained from East of England–Cambridge South Research Ethics Committee. Results will be disseminated by peer-reviewed publications and conference presentations, and findings will be shared with people living with CF, healthcare providers and relevant stakeholders.

NCT05562492.