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Cystic fibrosis related diabetes (CFRD) affects more than 30% of adults with cystic fibrosis (CF) in the UK. The Diabetes Trial Unit and the University of Cambridge are together conducting a trial, CL4P-CF, designed to test the efficacy, safety and quality of life of hybrid closed-loop glucose control compared with standard insulin therapy plus continuous glucose monitoring (CGM) in young people (≥16 years) and adults with cystic fibrosis-related diabetes. A hybrid closed-loop system includes a glucose sensor, a pump to deliver insulin subcutaneously, and an algorithm that automatically calculates how much insulin is needed in response to sensor glucose levels.  The goal of the trial is to determine if the hybrid closed-loop acheives better control of blood glucose compared with standard care.


An open-label, multicentre, randomised, 2-arm, single-period, parallel design study contrasting closed-loop insulin therapy with standard insulin therapy plus CGM over 6 months. CL4P-CF will recruit up to 128 participants from 7 UK clinical sites including: Cambridge University Hospitals NHS Foundation Trust (Addenbrooke's Hospital), Royal Papworth Hospital NHS Foundation Trust, Royal Brompton and Harefield Hospitals, King's College Hospital NHS Foundation Trust, Manchester University NHS Foundation Trust (Wythenshawe Hospital), University Hospitals Birmingham NHS Foundation Trust (Heartlands Hospital) and Oxford University Hospitals (Churchill Hospital).



To determine if the closed-loop system can improve glucose control determined by the proportion of time in target glucose range compared to standard insulin therapy with CGM in young people (≥16 years) and adults with CFRD.


To compare closed-loop glucose control against standard insulin therapy with CGM in terms of 1) efficacy, 2) safety, 3) acceptability and 4) value for money to the NHS.


Chief Investigator: Charlotte Boughton

Co-Investigators: Amanda Adler, Imogen Felton, Amanda Brennan, Vasiliki Kolovou, Joanne Barrett, Alistair Lumb, Julia Lawton, David Rankin, Malgorzata E Wilinska, Nick Oliver and Roman Hovorka

Study coordinators: Josephine Hayes and Nkemjika Abiakam


Sponsor: Cambridge University Hospitals NHS Foundation Trust and University of Cambridge

Funder: National Institute for Health and Care Research (NIHR)


Tel: +44 (0)1865857244


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