Ultra rapid lispro improves postprandial glucose control compared with lispro in patients with type 1 diabetes: Results from the 26‐week PRONTO‐T1D study

AIMS: To evaluate the efficacy and safety of ultra rapid lispro (URLi) versus lispro in adults with type 1 diabetes in a 26‐week, treat‐to‐target, phase 3 trial. MATERIALS AND METHODS: After an 8‐week lead‐in to optimize basal insulin glargine or degludec, patients were randomized to double‐blind mealtime URLi (n = 451) or lispro (n = 442), or open‐label post‐meal URLi (n = 329). The primary endpoint was change from baseline glycated haemoglobin (HbA1c) to 26 weeks (non‐inferiority margin 0.4%), with multiplicity‐adjusted objectives for postprandial glucose (PPG) excursions after a meal test. RESULTS: Both mealtime and post‐meal URLi demonstrated non‐inferiority to lispro for HbA1c: estimated treatment difference (ETD) for mealtime URLi −0.08% [95% confidence interval (CI) −0.16, 0.00] and for post‐meal URLi +0.13% (95% CI 0.04, 0.22), with a significantly higher endpoint HbA1c for post‐meal URLi versus lispro (P = 0.003). Mealtime URLi was superior to lispro in reducing 1‐ and 2‐hour PPG excursions during the meal test: ETD −1.55 mmol/L (95% CI −1.96, −1.14) at 1 hour and − 1.73 mmol/L (95% CI −2.28, −1.18) at 2 hours (both P < 0.001). The rate and incidence of severe, documented and postprandial hypoglycaemia (<3.0 mmol/L) was similar between treatments, but mealtime URLi demonstrated a 37% lower rate in the period >4 hours after meals (P = 0.013). Injection site reactions were reported by 2.9% of patients on mealtime URLi, 2.4% on post‐meal URLi, and 0.2% on lispro. Overall, the incidence of treatment‐emergent adverse events was similar between treatments. CONCLUSIONS: The results showed that URLi provided good glycaemic control, with non‐inferiority to lispro confirmed for both mealtime and post‐meal URLi, while superior PPG control was demonstrated with mealtime dosing.