Ultra-Rapid Lispro Efficacy and Safety Compared to Humalog(®) in Japanese Patients with Type 1 Diabetes: PRONTO-T1D Subpopulation Analysis

INTRODUCTION: We evaluated the efficacy and safety of ultra-rapid lispro (URLi) in comparison to lispro in a subgroup analysis of Japanese adults with type 1 diabetes mellitus from the phase 3 PRONTO-T1D trial. METHODS: After an 8-week lead-in to optimize basal insulin treatment, patients were randomized to 52-week double-blind mealtime URLi or lispro, or 26-week open-label postmeal URLi. The primary endpoint was change in hemoglobin A1c (HbA1c) from baseline (week 0) to week 26 between mealtime URLi and lispro. The multiplicity adjusted objectives were 1- and 2-h postprandial glucose (PPG) excursions after a meal test between mealtime URLi and lispro, and change in HbA1c from baseline to week 26 between postmeal URLi and mealtime lispro. RESULTS: This manuscript presents pre-specified exploratory analyses of 26-week data from Japanese patients randomized to double-blind URLi (n = 62) or lispro (n = 59), or open-label URLi (n = 46). Mean baseline HbA1c levels were 7.52% for mealtime URLi, 7.44% for lispro, and 7.51% for postmeal URLi at randomization. At week 26, the least squares mean (LSM) difference compared to lispro was 0.04% (95% confidence interval [CI] − 0.14 to 0.22) for mealtime URLi, and 0.16% (95% CI − 0.04 to 0.35) for postmeal URLi. In comparison to lispro, mealtime URLi resulted in statistically significantly lower 1- and 2-h PPG excursions during the mixed-meal tolerance test. LSM differences were − 40.5 mg/dL, 95% CI − 59.5 to 21.4 (− 2.25 mmol/L, 95% CI − 3.3 to − 1.2) for 1-h PPG excursions and − 51.7 mg/dL, 95% CI − 81.7 to − 21.8 (− 2.87 mmol/L, 95% CI − 4.5 to − 1.2) for 2-h PPG excursions at week 26. There were no significant treatment differences in rates of severe/overall hypoglycemia, or incidence of treatment-emergent adverse events. CONCLUSIONS: Mealtime and postmeal URLi provide effective and comparable glycemic control in Japanese patients. Mealtime URLi demonstrated more effective PPG control compared to lispro. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03214367.