Hybrid closed‐loop glucose control with faster insulin aspart (Fiasp) compared with standard insulin aspart in adults with type 1 diabetes: a double‐blind, multicentre, multinational, randomised, crossover study

Objective: We evaluated hybrid closed-loop glucose control with faster-acting insulin aspart (Fiasp) in adults with type 1 diabetes (T1D). We hypothesised that closed-loop with Fiasp provides similar efficacy as closed-loop with standard insulin aspart.

Research design and methods: In a double-blind, multinational, randomised, crossover study, 25 adults with T1D using insulin pump therapy (mean ± SD, age 38 ± 9 years, HbA1c 7.4 ± 0.8% [57 ± 8 mmol/mol]) underwent two 8-week periods of unrestricted living comparing hybrid closed-loop with Fiasp and hybrid closed-loop with standard insulin aspart in random order. During both interventions, the CamAPS FX closed-loop system incorporating Cambridge model predictive control algorithm was used.

Results: In an intention-to-treat analysis, the proportion of time sensor glucose was in target range (3.9-10.0 mmol/L; primary endpoint) was not different between interventions (75 ± 8% vs. 75 ± 8% for hybrid closed-loop with Fiasp vs. hybrid closed-loop with standard insulin aspart; mean-adjusted difference - 0.6 [95%CI -1.8 to 0.7%]; P < 0.001 for non-inferiority [non-inferiority margin 5%]). The proportion of time with sensor glucose <3.9 mmol/L (median [IQR] 2.4 [1.2-3.2%] vs. 2.9 [1.7-4.0%]; P = 0.01) and < 3.0 mmol/L (median [IQR] 0.4 [0.2-0.7%] vs. 0.7 [0.2-0.9%]; P = 0.03) was reduced with Fiasp vs. standard insulin aspart. There was no difference in mean glucose (8.1 ± 0.8 vs. 8.0 ± 0.8 mmol/L; P = 0.13) or glucose variability (SD of sensor glucose 2.9 ± 0.5 vs. 2.9 ± 0.5 mmol/L; P = 0.90). Total daily insulin requirements did not differ (49 ± 15 vs. 49 ± 15 units/day; P = 0.45). No severe hypoglycaemia or ketoacidosis occurred.

Conclusions: The use of Fiasp in CamAPS FX closed-loop system may reduce hypoglycaemia without compromising glucose control compared to standard insulin aspart in adults with T1D. This article is protected by copyright. All rights reserved.