Tubeless automated insulin delivery versus multiple daily injections in children and adults with type 1 diabetes with elevated HbA1c (RADIANT): a multicentre, international, parallel-group, open-label, randomised, controlled trial.

BACKGROUND

Automated insulin delivery (AID) systems have been shown to improve glycaemic outcomes in people with type 1 diabetes managed with insulin pump therapy. No randomised studies have evaluated the benefits of tubeless AID in both adults and children with suboptimal glycaemia compared with multiple daily injections. We aimed to evaluate the safety and efficacy of a tubeless AID system compared with multiple daily injections in this population.

METHODS

RADIANT was a multicentre, international, parallel-group, open-label, randomised, controlled trial done in 19 hospitals in the UK, Belgium, and France. Participants aged 4-70 years with type 1 diabetes managed with multiple daily injections and continuous glucose monitoring and who had HbA1c levels of 7·5-11% (58-97 mmol/mol) were randomly assigned (2:1) to tubeless AID or control (multiple daily injections) using a permuted-block design. Participant and study teams were not masked to group allocation. The primary outcome was the adjusted between-group difference in HbA1c at 13 weeks assessed for superiority. Primary and safety outcomes were assessed in the modified intention-to-treat population (all randomly assigned participants). The study is registered with ClinicalTrials.gov, NCT05923827, and has been completed.

FINDINGS: Between Sept 11, 2023, and April 26, 2024, 188 participants were randomly assigned to the AID group (n=125) or the control group (n=63). The AID group had a greater reduction in HbA1c, from 8·1% (SD 0·7; 65 mmol/mol [SD 7·7]) at baseline to 7·2% (0·6; 55 mmol/mol [6·6]) at 13 weeks, compared with the control group, from 8·1% (0·6; 65mmol/mol [6·6]) at baseline to 8·0% (0·7; 64 mmol/mol [7·7]) at 13 weeks, with an adjusted mean difference of -0·8% (95% CI -1·0 to -0·6; -8·7 mmol/mol [95% CI -10·9 to -6·6]; p<0·0001). During the 13-week trial, no episodes of severe hypoglycaemia or diabetic ketoacidosis occurred in either treatment group. 39 adverse events were reported among 28 participants in the AID group, and three adverse events among three participants in the control group. Two serious adverse events (Kawasaki disease and acute coronary syndrome) occurred in the AID group unrelated to the study device or procedure.

INTERPRETATION: Results from this trial show the clinical efficacy of direct transition from multiple daily injections to tubeless AID in adults and children with type 1 diabetes, with no safety concerns, supporting AID as a therapeutic option within standard of care for people with type 1 diabetes.

FUNDING: Insulet Corporation.