Background: Insulin degludec (IDeg) has significantly lower day-to-day and within-day variability compared to insulin glargine (IGlar) 100U/mL (U100) and 300U/mL (U300). Here, we report post hoc assessments to confirm the robustness of these observations while accounting for potential experimental confounders.
Methods: Two euglycemic clamp studies in type 1 diabetes patients, comparing IDeg to IGlar-U100 (Study A, parallel design, 54 patients; Study B, crossover, 22 patients) and one study comparing IDeg to IGlar-U300 (Study C, crossover, 57 patients), all dosed at 0.4U/kg, were evaluated. Pharmacodynamic parameters were assessed at steady state from glucose infusion rate (GIR) profiles following three 24-hour euglycemic clamps in Studies A (162 clamps) and C (342 clamps), and one 42-hour clamp in Study B (44 clamps).
Results: Pooled data (Studies A and B) showed that IDeg had an even distribution of glucose-lowering effect over the 24-hour dosing interval that was consistent with Study C. IGlar-U100 showed a constant decrease in glucose-lowering effect over 24 hours while IGlar-U300 had a lower effect in the middle of the dosing interval (6-18 hours). Relative within-day variability of IDeg was 40% and 37% lower than IGlar-U100 and -U300, respectively. Exclusion of profiles with low response in Study C (19/342 clamps) did not impact the difference in the distribution of glucose-lowering effect or within-day variability. Day-to-day variability was significantly lower with IDeg compared to IGlar-U100 and -U300 based on smoothed and unsmoothed GIR data.
Conclusions: Significantly lower relative within-day and day-to-day variability was confirmed irrespective of experimental considerations for IDeg compared to IGlar-U100 and IGlar-U300.
Keywords: day-to-day variability; degludec; glargine; within-day variability.