Clinical Pharmacology of Fast-Acting Insulin Aspart Versus Insulin Aspart Measured as Free or Total Insulin Aspart and the Relation to Anti-Insulin Aspart Antibody Levels in Subjects with Type 1 Diabetes Mellitus.

BACKGROUND: Fast-acting insulin aspart (faster aspart) is an ultra-fast-acting formulation of insulin aspart (IAsp). This post hoc analysis investigated the pharmacokinetics of faster aspart versus IAsp, measured as free or total IAsp, and the relationship between anti-IAsp antibodies and the pharmacokinetics/pharmacodynamics of faster aspart and IAsp. METHODS: Free and total IAsp concentrations and anti-IAsp antibodies were determined in adults with type 1 diabetes mellitus receiving subcutaneous faster aspart and/or IAsp in four single-dose clinical pharmacology trials (n = 175) and a 26-week phase IIIa trial (n = 1040). Pharmacodynamics were assessed by euglycaemic clamp or meal test, respectively. RESULTS: The pharmacokinetic profile was left-shifted and early exposure was greater with faster aspart versus IAsp independent of free or total IAsp assay. The faster aspart-IAsp difference in the time to 50% of maximum IAsp concentration in the early part of the pharmacokinetic profile (tEarly 50 % Cmax) [95% confidence interval (CI)] was - 8.8 [- 10.0 to - 7.5] and - 7.6 [- 8.8 to - 6.4] min for free and total IAsp, respectively. The faster aspart/IAsp ratio for the area under the concentration-time curve (AUC) for IAsp from time zero to 30 min (AUCIAsp,0-30 min) [95% CI] was 1.88 [1.74-2.04] and 1.77 [1.64-1.90] for free and total IAsp. Higher anti-IAsp antibody levels were associated with a lower ratio of free/total IAsp for the total AUC for IAsp (AUCIAsp,0-t). Early glucose-lowering effect (AUC for the glucose infusion rate [GIR] from time zero to 60 min [AUCGIR,0-60 min]) was greater by 25-44% for faster aspart versus IAsp independent of anti-IAsp antibody levels. Total glucose-lowering effect (total AUC for GIR [AUCGIR,0-t]) in a clamp and 1-h postprandial glucose increment in a meal test appeared essentially unaffected by anti-IAsp antibodies. CONCLUSIONS: Faster aspart provides accelerated pharmacokinetics versus IAsp regardless if based on free or total IAsp assay. Higher anti-IAsp antibodies increase total IAsp concentrations but do not influence faster aspart nor IAsp pharmacodynamics. CLINICALTRIALS. GOV IDENTIFIERS: NCT01618188, NCT02003677, NCT01934712, NCT02568280, NCT01831765.