Faster-acting insulin aspart: earlier onset of appearance and greater early pharmacokinetic and pharmacodynamic effects than insulin aspart

Aims: To evaluate the pharmacokinetics and pharmacodynamics of faster-acting insulin aspart and insulin aspart in a randomized, single-centre, double-blind study. Methods: Fifty-two patients with type 1 diabetes (mean age 40.3 years) received faster-acting insulin aspart, insulin aspart, or another faster aspart formulation (not selected for further development), each as a single 0.2 U/ kg subcutaneous dose, under glucose-clamp conditions, in a three-way crossover design (3-12 days washout between dosing). Results: Faster-acting insulin aspart had a faster onset of exposure compared with insulin aspart, shown by a 57% earlier onset of appearance [4.9 vs 11.2 min; ratio 0.43, 95% confidence interval (CI) 0.36; 0.51], a 35% earlier time to reach 50% maximum concentration (20.7 vs 31.6min; ratio 0.65, 95% CI 0.59; 0.72) and a greater early exposure within 90min after dosing. The greatest difference occurred during the first 15min, when area under the serum insulin aspart curve was 4.5-fold greater with faster-acting insulin aspart than with insulin aspart. Both treatments had a similar time to maximum concentration, total exposure and maximum concentration. Faster-acting insulin aspart had a significantly greater glucose-lowering effect within 90 min after dosing [largest difference: area under the curve for the glucose infusion rate (AUC(GIR)),(0-30) (min) ratio 1.48, 95% CI 1.13; 2.02] and 17% earlier time to reach 50% maximum glucose infusion rate (38.3 vs 46.1min; ratio 0.83, 95% CI 0.73; 0.94). The primary endpoint (AUC(GIR), (0-2) (h)) was 10% greater for faster-acting insulin aspart, but did not reach statistical significance (ratio 1.10, 95% CI 1.00; 1.22). Both treatments had similar total and maximum glucose-lowering effects, indicating similar overall potency. Conclusions: Faster-acting insulin aspart was found to have earlier onset and higher early exposure than insulin aspart, and a greater early glucose-lowering effect, with similar potency.