The aim of this randomized double-blind study was to compare the within-subject variability of the glucoselowering effect of a novel insulin analog, insulin detemir, with that of insulin glargine and NPH insulin in people with type 1 diabetes. Fifty-four subjects (32 males and 22 females, age 38 ؎ 10 years [ D aily clinical experience indicates that subcutaneous administration of insulin often does not result in a reproducible metabolic effect even when injected at the same dose under comparable conditions. Nonetheless, only few studies have assessed the variability of insulin absorption after subcutaneous administration (1-7), and even fewer have assessed the variability in the glucose-lowering effect of insulin. Thus, even though variability of the glucoselowering effect is regarded as a major obstacle to achieving optimal metabolic control (8 -10), our knowledge of the variability of insulin preparations is surprisingly scarce (11,12). This is particularly true for basal insulin preparations. The few studies available report coefficients of variation (CVs) for within-and between-subject variability in the pharmacodynamic action of long-acting zinc insulin preparations to be between 35 and 55% (9) and even greater for NPH insulin (13). Compared with these findings, the variability (CV) of short-acting insulin preparations, which are reported in the range of "only" 20 -30% (10,11), are less of a concern. The development of the new long-acting insulin analogs such as insulin detemir and insulin glargine has raised the hope of concurrent lower within-subject variability. However, insulin glargine does not appear to provide any improvement in the within-subject variability compared with NPH insulin (8).The aim of this study was to compare the within-subject variability in the glucose-lowering effect of the novel long-acting insulin analog insulin detemir with that of NPH insulin and insulin glargine. Insulin detemir [Lys B29 (N ε -tetradecanoyl) des(B30) human insulin] is the first of a new class of long-acting soluble insulin analogs. Its prolonged duration of action is attributable to a combination of increased self-association (hexamer stabilization and hexamer-hexamer interaction) and albumin binding due to acylation of the amino acid lysine in position B29 with a 14 C fatty acid (myristic acid). Insulin detemir is highly albumin bound in the interstitial fluid and in plasma (14) and has been shown to elicit a protracted metabolic action, with a slow onset of action and a less pronounced peak of action compared with that observed for NPH insulin (15,16).

Aims: Insulin degludec (IDeg) is a new-generation basal insulin with an ultra-long duration of action. We compared the pharmacodynamic (PD) variability of IDeg and insulin glargine (IGlar) under steady-state conditions.Methods: Day-to-day variability in glucose-lowering effect was investigated in 54 subjects with type 1 diabetes who underwent a 24-h euglycaemic glucose clamp on the 6th, 9th and 12th day of treatment with 0.4 U/kg of IDeg or IGlar once daily. Within-subject variability was estimated using a linear mixed model on log-transformed PD endpoints derived from the glucose infusion rate (GIR) profiles during the clamps. Results:For IDeg the day-to-day variability in glucose-lowering effect was four-times lower than for IGlar for total metabolic effect (AUC GIR,0-24h,SS , CV 20% vs. 82%) and for the last 22 h [AUC GIR,2-24h,SS (not influenced by intravenous insulin during the clamp), CV 22% vs. 92%]. Furthermore, lower variability in the maximum effect was observed for IDeg vs. IGlar (GIR max,SS , CV 18% vs. 60%). The lower within-subject variability of IDeg was consistent over time (CVs of 33% for AUC GIR,0-2h,SS , 32% for AUC GIR,10-12h,SS and 33% for AUC GIR,22-24h,SS ), whereas the variability of IGlar was higher and increased substantially 8 h post-dosing (CVs of 60% for AUC GIR,0-2h,SS , 135% for AUC GIR,10-12h,SS and 115% for AUC GIR,22-24h,SS ). Conclusions:These results show that IDeg has a significantly more predictable glucose-lowering effect from day to day than IGlar.

Aims: Insulin degludec (IDeg) is a new-generation, ultra-long-acting basal insulin that forms soluble multihexamers upon subcutaneous injection, resulting in a depot from which IDeg is absorbed slowly and continuously into circulation. This double-blind, two-period, incomplete block cross-over trial investigated the pharmacodynamic and pharmacokinetic properties of IDeg at steady state (SS) in people with type 2 diabetes.Methods: Forty-nine subjects treated with insulin without concomitant oral anti-diabetic drugs were given IDeg (0.4, 0.6 and/or 0.8 U/kg) once daily for two 6-day periods, separated by an interval of 13-21 days. Following dosing on Day 6, subjects underwent a 26-h euglycaemic glucose clamp (Biostator ® ; clamp blood glucose level: 90 mg/dl; 5.0 mmol/l). Pharmacokinetic samples were taken until 120 h after last dosing.Results: For all dose levels, the mean glucose infusion rate (GIR) profiles were flat and stable. The glucose-lowering effect of IDeg was evenly distributed over the dosing interval τ , with area under the curve (AUC) for each of the four 6-h intervals being approximately 25% of the total AUC (AUC GIR,τ ,SS ). Total glucose-lowering effect increased linearly with increasing dose. The blood glucose levels of all subjects stayed very close to the clamp target until end of clamp. The terminal half-life of IDeg was approximately 25 h at steady state. IDeg was well tolerated and no safety concerns were identified. No injection site reactions were reported. Conclusions:IDeg has a flat and consistent glucose-lowering effect in people with type 2 diabetes.

Aim: This study compared the time-action profiles of the novel albumin-bound basal insulin analogue NN344 with those of insulin detemir and insulin glargine in individuals with type 2 diabetes. Methods: Twenty-seven insulin-treated men with type 2 diabetes [body mass index 30.8 AE 2.6 kg/m 2 (mean AE s.d.), haemoglobin A 1c 7.6 AE 1.1%] were enrolled in this randomized, double-blind trial and participated in six euglycaemic glucose clamp experiments [target blood glucose (BG) 5 mmol/l] each. Participants received NN344 in three experiments at a dose of 0.8, 1.6 and 2.8 dosing units (DU) (1 DU corresponds to 6 nmol NN344) per kilogram of body weight. In the other three experiments, the participants received 0.4, 0.8 and 1.4 U/kg of either insulin detemir or insulin glargine. The insulin preparations were characterized with regards to their effects on glucose infusion rates (GIRs) (in particular duration of action and within-subject and between-subject variabilities), BG, C-peptide, free fatty acids (FFA), endogenous glucose production (EGP) and peripheral glucose uptake (PGU) over 24 h post-dose.Results: The mean GIR profiles for all three preparations were similar in shape/flatness and showed increasing effect (area under the curve for GIR: AUC-GIR total ) with increasing dose The duration of action increased with rising doses of all insulin preparations, without major differences between treatments. BG remained below 7 mmol/l in nearly all the experiments. Within-subject variability was lower for the albumin-bound insulin analogues, insulin detemir and NN344, than for insulin glargine (p < 0.0001). Between-subject variability did not differ between treatments, nor did the effects on BG, C-peptide, FFA, EGP or PGU.Conclusions: In individuals with type 2 diabetes, the time-action profiles and the duration of action of the albuminbound insulin analogues, insulin detemir and NN344, were comparable with those of insulin glargine, whereas withinsubject variability in the metabolic effect was significantly lower. Therefore, insulin detemir and NN344 seem to be as well suited as insulin glargine for once-daily administration in type 2 diabetes. The better predictability may be an important characteristic of the albumin-bound analogues as insulin detemir has already been shown to improve hypoglycaemia.

IDeg has a longer half-life (> 25 h) than IGlar. Exposure and glucose-lowering effects are more stable and evenly distributed across one dosing interval for IDeg versus IGlar (Clinical trials.gov identifier: NCT01114542).

AimTo compare day‐to‐day and within‐day variability in glucose‐lowering effect between insulin degludec (IDeg) and insulin glargine 300 U/mL (IGlar‐U300) in type 1 diabetes.Materials and methodsIn this double‐blind, crossover study, patients were randomly assigned to 0.4 U/kg of IDeg or IGlar‐U300 once daily for two treatment periods lasting 12 days each. Pharmacodynamic variables were assessed at steady‐state from the glucose infusion rate profiles of three 24‐hour euglycaemic glucose clamps (days 6, 9 and 12) during each treatment period.ResultsOverall, 57 patients completed both treatment periods (342 clamps). The potency of IGlar‐U300 was 30% lower than IDeg (estimated ratio 0.70, 95% confidence interval [CI] 0.61; 0.80; P < .0001). The distribution of glucose‐lowering effect was stable across 6‐hour intervals (24%‐26%) for IDeg, while IGlar‐U300 had greater effects in the first (35%) and last (28%) intervals compared with 6 to 12 hours (20%) and 12 to 18 hours (17%). Within‐day variability (relative fluctuation) was 37% lower with IDeg than with IGlar‐U300 (estimated ratio IDeg/IGlar‐U300: 0.63, 95% CI 0.54; 0.73; P < .0001). The day‐to‐day variability in glucose‐lowering effect with IDeg was approximately 4 times lower than IGlar‐U300 (variance ratio IGlar‐U300/IDeg: 3.70, 95% CI 2.42; 5.67; P < .0001). The day‐to‐day variability in glucose‐lowering effect assessed in 2‐hour intervals was consistently low with IDeg over 24 hours, but steadily increased with IGlar‐U300 to a maximum at 10 to 12 hours and 12 to 14 hours after dosing (variance ratios 12.4 and 11.4, respectively).Conclusion IDeg has lower day‐to‐day and within‐day variability than IGlar‐U300 and a more stable glucose‐lowering effect, which might facilitate titration and enable tighter glycaemic control with a reduced risk of hypoglycaemia.

AimsTo evaluate the pharmacokinetics and pharmacodynamics of faster‐acting insulin aspart and insulin aspart in a randomized, single‐centre, double‐blind study.MethodsFifty‐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).ResultsFaster‐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 31.6 min; ratio 0.65, 95% CI 0.59; 0.72) and a greater early exposure within 90 min after dosing. The greatest difference occurred during the first 15 min, 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 (AUCGIR), 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 46.1 min; ratio 0.83, 95% CI 0.73; 0.94). The primary endpoint (AUCGIR , 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.ConclusionsFaster‐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.

Introduction/aimInsulin degludec/insulin aspart (IDegAsp) is a soluble co-formulation of long-acting and short-acting insulin analogs. The primary objective of this study was to investigate the pharmacodynamic response of once-daily IDegAsp dosing in patients with type 1 diabetes. Pharmacokinetic response, as well as safety and tolerability, were assessed as secondary objectives.MethodologyThis was a single-center, open-label, single-arm study. Twenty-two subjects received once-daily insulin degludec (IDeg) (0.42 U/kg) for five consecutive days [with separate bolus insulin aspart (IAsp) as needed for safety and glycemic control], to achieve clinical steady state of the basal component. On Day 6, they received a single injection of IDegAsp (0.6 U/kg, comprising 0.42 U/kg IDeg and 0.18 U/kg IAsp). Pharmacodynamic response was assessed using a 30-h euglycemic glucose clamp, with blood glucose stabilized at a target of 5.5 mmol/L.ResultsThe glucose infusion rate profile showed a rapid onset of action and a distinct peak due to IAsp, followed by a separate, flat and stable basal glucose-lowering effect due to the IDeg component. Modeling data suggested that the pharmacodynamic profile of IDegAsp was retained with twice-daily dosing (allowing for coverage of two main meals daily). IDegAsp was well tolerated and no safety issues were identified in this trial.ConclusionsIn conclusion, the IAsp component of IDegAsp has a fast onset of appearance and a peak covering the prandial phase, while the IDeg component has a flat and an evenly distributed pharmacokinetic profile over 24 h. IDegAsp is the first co-formulation of a basal insulin analog with an ultra-long duration of action and a mealtime insulin analog in a single soluble injection. These properties translate into clinically relevant benefits, including improved glycemic control and reduction in hypoglycemia.Electronic supplementary materialThe online version of this article (doi:10.1007/s13300-014-0070-2) contains supplementary material, which is available to authorized users.