Predicting human half-life for insulin analogs: An inter-drug approach.

An inter-drug approach, applying pharmacokinetic information for insulin analogs in different animal species, rat, dog and pig, performed better compared to allometric scaling for human translation of intra-venous half-life and only required data from a single animal species for reliable predictions. Average fold error (AFE) between 1.2-1.7 were determined for all species and for multispecies allometric scaling AFE was 1.9. A slightly larger prediction error for human half-life was determined from in vitro human insulin receptor affinity data (AFE on 2.3-2.6). The requirements for the inter-drug approach were shown to be a span of at least 2 orders of magnitude in half-life for the included drugs and a shared clearance mechanism. The insulin analogs in this study were the five fatty acid protracted analogs: Insulin degludec, insulin icodec, insulin 320, insulin 338 and insulin 362, as well as the non-acylated analog insulin aspart.

The Effect of Various Degrees of Renal or Hepatic Impairment on the Pharmacokinetic Properties of Once-Weekly Insulin Icodec.

BACKGROUND AND OBJECTIVE: Icodec is a once-weekly insulin being developed to provide basal insulin coverage in diabetes mellitus. This study evaluated the effects of renal or hepatic impairment on icodec pharmacokinetics. METHODS: Two open-label, parallel-group, single-dose (1.5 U/kg subcutaneously) trials were conducted. In a renal impairment trial, 58 individuals were allocated to normal renal function (measured glomerular filtration rate ≥ 90 mL/min), mild (60 to < 90 mL/min), moderate (30 to < 60 mL/min) or severe (< 30 mL/min) renal impairment or end-stage renal disease. In a hepatic impairment trial, 25 individuals were allocated to normal hepatic function or mild (Child-Pugh Classification grade A), moderate (grade B) or severe (grade C) hepatic impairment. Blood was sampled frequently for a pharmacokinetic analysis until 35 days post-dose. RESULTS: The shape of the icodec pharmacokinetic profile was not affected by renal or hepatic impairment. Total icodec exposure was greater for mild (estimated ratio [95% confidence interval]: 1.12 [1.01; 1.24]), moderate (1.24 [1.12; 1.37]) and severe (1.28 [1.16; 1.42]) renal impairment, and for end-stage renal disease (1.14 [1.03; 1.28]), compared with normal renal function. It was also greater for mild (1.13 [1.00; 1.28]) and moderate (1.15 [1.02; 1.29]) hepatic impairment versus normal hepatic function. There was no statistically significant difference between severe hepatic impairment and normal hepatic function. Serum albumin levels (range 2.7-5.1 g/dL) did not statistically significantly influence icodec exposure. CONCLUSIONS: The clinical relevance of the slightly higher icodec exposure with renal or hepatic impairment is limited as icodec should be dosed according to individual need. No specific icodec dose adjustment is required in renal or hepatic impairment. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT03723785 and NCT04597697.

A phase-I randomized euglycemic clamp study to demonstrate the pharmacokinetic and pharmacodynamic equivalence of an insulin degludec biosimilar (B01411) with the reference product in healthy Chinese volunteers.

BACKGROUND: B01411 is a biosimilar candidate manufactured by Jilin Huisheng Biopharmaceutical Co. Ltd for the reference insulin degludec (Tresiba) (IDeg). This study aimed to evaluate the pharmacokinetics (PK), pharmacodynamics (PD), and safety of the two IDeg products and to assess the PK/PD similarity of B01411 compared with the reference IDeg product. RESEARCH DESIGN & METHODS: A single-center, single-dose, randomized, crossover, open-labeled, phase I, euglycemic clamp study in healthy Chinese subjects to examine the bioequivalence of B01411 (0.4 U/kg) compared with the reference IDeg product. Blood samples were collected at a predefined time for the analysis of blood glucose (BG), IDeg, and C-peptide concentrations. The glucose infusion rate (GIR) was adjusted to maintain the BG at approximately 0.28 mmol/L below baseline throughout the clamp. RESULTS: Thirty-two subjects (20 males and 12 females) were enrolled, 31 of whom received both treatments. The 90% confidence intervals for the ratio of the least-squares geometric means for AUCIDeg,0-24 h, AUCGIR,0-24 h, IDegmax, and GIRmax were all in the range of 0.80-1.25. Only one adverse event of puncture site bruising occurred once in a subject in the B01411 group. CONCLUSION: B01411 exhibited a pharmacokinetic and pharmacodynamic similarity to the reference product. Both IDeg products were well tolerated. CLINICAL TRIAL REGISTRATION: http://www.chinadrugtrials.org.cn/index.html#. Identifier is CTR20192122.

Current Status of Weekly Insulin Analogs and Their Pharmacokinetic/Pharmacodynamic Evaluation by the Euglycemic Clamp Technique.

Diabetes mellitus represents a significant global health threat characterized by hyperglycemia caused by inadequate insulin secretion and/or insulin resistance. Exogenous insulin supplements had been recognized as a crucial treatment for achieving successful glycemic control in patients with Type 1 and most patients with Type 2 diabetes. Over the past century, substantial progress has been made in the development of novel insulin formulations, including the super-fast-acting and long-acting basal insulin analogs, of which the latter is indispensable for the management of nocturnal fasting and intraprandial blood glucose within the normal physiological range. Recently, combining chemical and genetic engineering with drug optimization have resulted in a formidable evolution in ultra-long-acting weekly insulin. Here, the current state of once-weekly insulin analogs and the euglycemic clamp technique used in the early clinical development to elucidate the pharmacokinetics and pharmacodynamics of this type of novel weekly insulin analogs were systematically overviewed.

The Effect of BMI on Pharmacokinetic and Pharmacodynamic Parameters of Insulin Degludec: Results from an Euglycemic Glucose Clamp Study.

PURPOSE: This study evaluated the effect of body mass index (BMI) on pharmacokinetic (PK) and pharmacodynamic (PD) parameters of insulin degludec in healthy Chinese males, depending on an euglycemic glucose clamp study. METHODS: Sixty-five healthy male subjects were divided into four groups according to quartile of BMI value. Group A: BMI ≤ 20.7 kg/m2; group B: 20.7 < BMI ≤ 22.5 kg/m2; group C: 22.5 < BMI ≤ 23.6 kg/m2; group D: BMI > 23.6 kg/m2. Each volunteer received a single subcutaneous dose (0.4 U/kg) of insulin degludec and accepted a 24-h euglycemic glucose clamp study. The primary PK parameters were maximum observed drug concentration (Cmax) and the area under the curve (AUCINS) for the specified time intervals. The primary PD parameters were the time to the start of glucose infusion (Tonset), maximal glucose infusion rate (GIRmax) and area under the curve (AUCGIR) for the specified time intervals. The differences of these PK/PD parameters were compared among groups. RESULTS: Cmax and the AUC of insulin (0-6 h, 6-12 h and 0-24 h) were more than onefold higher in group A than those in groups B, C, D, and the concentration-time curve of group A was significantly shifted to the left compared with the other three groups. The GIRmax, total AUCGIR, and AUCGIR for each time interval were significantly higher in group A than those in other three groups. The proportion of AUCGIR in group A was the lowest proportion among four groups seen in the late stage. Multiple linear regression analysis showed that BMI was negatively correlated with AUCGIR,0-24 h. CONCLUSIONS: Insulin degludec in healthy Chinese male subjects with BMI ≤ 20.7 kg/m2 had a faster absorption, clearance, and a stronger glucose-lowering effect, but a steeper decrease of insulin action in the late stage after dosing.

Molecular Engineering of Efficacious Mono-Valent Ultra-Long Acting Two-Chain Insulin-Fc Conjugates.

Here, we describe molecular engineering of monovalent ultra-long acting two-chain insulin-Fc conjugates. Insulin-Fc conjugates were synthesized using trifunctional linkers with one amino reactive group for reaction with a lysine residue of insulin and two thiol reactive groups used for re-bridging of a disulfide bond within the Fc molecule. The ultra-long pharmacokinetic profile of the insulin-Fc conjugates was the result of concertedly slowing insulin receptor-mediated clearance by (1) introduction of amino acid substitutions that lowered the insulin receptor affinity and (2) conjugating insulin to the Fc element. Fc conjugation leads to recycling by the neonatal Fc receptor and increase in the molecular size, both contributing to the ultra-long pharmacokinetic and pharmacodynamic profiles.

Efficacy, Pharmacokinetics, Biodistribution and Excretion of a Novel Acylated Long-Acting Insulin Analogue INS061 in Rats.

PURPOSE: Long-acting insulin analogues are known to be a major player in the management of glucose levels in type I diabetic patients. However, highly frequent hypo- and hyperglycemic incidences of current long-acting insulins are the important factor to limit stable management of glucose level for clinical benefits. To further optimize the properties for steadily controlling glucose level, a novel long-acting insulin INS061 was designed and its efficacy, pharmacokinetics, biodistribution and excretion profiles were investigated in rats. METHODS: The glucose-lowering effects were evaluated in a streptozocin-induced diabetic rats compared to commercial insulins via subcutaneous administration. The pharmacokinetics, biodistribution, and excretion were examined by validated analytical methods including radioactivity assay and radioactivity assay after the precipitation with TCA and the separation by HPLC. RESULTS: INS061 exhibited favorable blood glucose lowering effects up to 24 h compared to Degludec. Pharmacokinetic study revealed that the concentration-time curves of INS061 between two administration routes were remarkably different. Following intravenous administration, INS061 was quickly distributed to various organs and tissues and slowly eliminated over time with urinary excretion being the major route for elimination, and the maximum plasma concentrations (Cmax) and systemic exposures (AUC) increased in a linear manner. CONCLUSION: The present structural modifications of human insulin possessed a long-acting profile and glucose-lowering function along with favorable in vivo properties in rats, which establish a foundation for further preclinical and clinical evaluation.

Similar pharmacokinetics and pharmacodynamics of a new biosimilar and reference insulin aspart in healthy Chinese males.

Insulin aspart (IAsp) is one of the main therapies used to control blood glucose after a meal. This study aimed to compare the pharmacokinetics (PK) and pharmacodynamics (PD) of 2 rapid-acting IAsp products: a new IAsp biosimilar (RD10046) and NovoRapid. In a single-center, randomized, single-dose, 2-period, crossover, euglycemic clamp study (registry number: CTR20180517, registration date: 2018-05-30), healthy Chinese males were randomized to receive 0.2 U/kg of the IAsp biosimilar RD10046 and NovoRapid under fasted conditions on two separate occasions. PK and PD were assessed for up to 10 h. Of the 30 randomized subjects, all 30 completed both treatment periods. The PK (area under the curve [AUC] of total IAsp; maximum observed IAsp concentration [Cmax]) and PD (maximum glucose infusion rate [GIRmax]; total glucose infusion during the clamp [AUCGIR,0-10h]) were similar between the new IAsp biosimilar RD10046 and NovoRapid. In all cases, the 90% CIs for the ratios of the geometric means were completely contained in the prespecified acceptance limits of 0.80-1.25. No hypoglycemic events, allergic reactions, or local injection adverse reactions occurred in this trial. We concluded that the studied IAsp biosimilar (RD10046) was bioequivalent to NovoRapid.

Pharmacokinetics, tissue distribution and excretion of a novel long-acting human insulin analogue - recombinant insulin LysArg in rats.

As a novel long-acting recombinant human insulin analogue, it is necessary to carry out the preclinical research for insulin LysArg. The purpose of this study was to characterise the pharmacokinetic, tissue distribution and excretion of insulin LysArg and provide a reference for its development. Three methods were used to measure the content of insulin LysArg in biological samples after a single subcutaneous administration in rats, including radioassay, radioassay after precipitation with TCA and separation by HPLC. After Subcutaneous administration of recombinant insulin LysArg 1, 2, 4 U/kg in rats, it showed both Cmax and AUC0-t were positively correlated with the dose. In the meanwhile, after a single subcutaneous administration of recombinant insulin LysArg at 2 U/kg in rats, the amount of radioactivity in most organs was highest at 1.5 h and then decreased gradually, no accumulation was found. The highest level of insulin LysArg was observed in the kidney. Like other macromolecules, insulin LysArg was mainly excreted from urine. The study fully illustrated the pharmacokinetic pattern of insulin LysArg, provided valuable informations to support its further development about safety and toxicology.

Simultaneous quantitative determination of liraglutide and insulin degludec in rat plasma by liquid chromatography-tandem mass spectrometry method and its application.

A simple, fast and high-throughput LC-tandem mass spectrometry method was developed and validated to simultaneously measure liraglutide and insulin degludec in rat plasma. After protein precipitation, plasma samples were subjected to gradient elution using an InertSustain Bio C18 column with 1000/20/1 water/acetonitrile/formic acid (v/v/v) and 1000/1 acetonitrile/formic acid (v/v) as the mobile phase. The method was validated from 1.00 to 500 ng/mL of liraglutide and insulin degludec. Further, the extraction recovery from the plasma was 41.8%-49.2% for liraglutide and 56.5%-69.7% for insulin degludec. Intra- and inter-day precision of liraglutide was 3.5%-9.4% and 8.4%-9.8%, respectively, whereas its accuracy was between -12.6% and -1.3%. Intra- and inter-day precision of insulin degludec was 5.2%-13.6% and 11.8%-19.1%, respectively, showing an accuracy between -3.0% and 9.9%. As a result, the method was successfully applied to a pharmacokinetics study of liraglutide and insulin degludec following a single-dose subcutaneous administration to rats.

In Silico Head-to-Head Comparison of Insulin Glargine 300 U/mL and Insulin Degludec 100 U/mL in Type 1 Diabetes.

Background: Second-generation long-acting insulin glargine 300 U/mL (Gla-300) and degludec 100 U/mL (Deg-100) provide novel basal insulin therapies for the treatment of type 1 diabetes (T1D). Both offer a flatter pharmacokinetic (PK) profile than the previous generation of long-acting insulins, thus improving glycemic control while reducing hypoglycemic events. This work describes an in silico head-to-head comparison of the two basal insulins on 24-h glucose profiles and was used to guide the design of a clinical trial. Materials and Methods: The Universities of Virginia (UVA)/Padova T1D simulator describes the intra-/interday variability of glucose-insulin dynamics and thus provides a robust bench-test for assessing glucose control for basal insulin therapies. A PK model describing subcutaneous absorption of Deg-100, in addition to the one already available for Gla-300, has been developed based on T1D clinical data and incorporated into the simulator. One hundred in silico T1D subjects received a basal insulin dose (Gla-300 or Deg-100) for 12 weeks (8 weeks uptitration, 4 weeks stable dosing) by morning or evening administration in a basal/bolus regimen. The virtual patients were uptitrated to their individual doses with two different titration rules. Results: The last 2-week simulated continuous glucose monitoring data were used to calculate various outcome metrics for both basal insulin treatments, with primary outcome being the percent time in glucose target (70-140 mg/dL). The simulations show no statistically significant difference for Gla-300 versus Deg-100 in the main endpoints. Conclusions: This work suggests comparable glucose control using either Gla-300 or Deg-100 and was used to guide the design of a clinical trial intended to compare second-generation long-acting insulin analogues.

Biosynthetic Human Insulin and Insulin Analogs.

BACKGROUND: Biosynthetic human insulins and analogs have replaced animal insulins and permitted structural modifications to alter the rate of absorption, duration of action, improve reproducibility of effects, and modulate relative efficacy in various target tissues. Several forms of rapidly acting insulins nearly achieve rapid pharmacokinetics and pharmacodynamics similar to first-phase insulin release. There is need for even faster-acting analogs to mimic normal physiology and improve control of postprandial glycemic excursions. Two biosynthetic insulin analogs have sufficiently long duration of action for use as once-daily basal insulins; controversy persists regarding their respective risks of hypoglycemia and relative glycemic variability. RESULTS: Basal-bolus therapy and insulin pump therapy, including closed-loop automated insulin delivery, require rapid-acting insulin analogs. The longer acting insulins can provide stable, reproducible basal insulin with reduced rates of hypoglycemia, particularly nocturnal hypoglycemia, greater efficacy in reducing mean glucose and glucose variability while increasing time in glucose target range. Inhalable human insulin provides very rapid action. Premixture of rapid-acting analogs with protamine has been useful for some patients with type 2 diabetes. An insulin analog with preferential efficacy at the liver has been developed and tested clinically but not marketed. Current research is aimed at developing even faster-acting insulin analogs. Long-acting basal insulins coformulated with GLP-1 receptor agonists or with a rapidly acting insulin analog have valuable clinical applications. Excipients, chaperones, local heating of the infusion site, and hyaluronidase have also been used to accelerate the absorption of insulin analogs. CONCLUSIONS: Biosynthetic human insulins have radically revolutionized management of both type 1 and type 2 diabetes worldwide. The ability to manipulate the structure and formulation of insulin provides for more physiologic pharmacokinetics and pharmacodynamics, enabling improved glycemic control, reduced risk of hypoglycemia, and reduced rates of long-term complications.

Comparison of pharmacodynamics and pharmacokinetics of insulin degludec and insulin glargine 300 U/mL in healthy cats.

Insulin glargine 300 U/mL (IGla-U300) and insulin degludec (IDeg) are synthetic insulin analogs designed as basal insulin formulations. In people, IGla-U300 is more predictable and longer acting compared with glargine 100 U/mL. The duration of action of IDeg in people is > 42 h, allowing flexibility in daily administration. We hypothesized that IDeg would have longer duration of action compared with IGla-U300 in healthy purpose-bred cats. Seven cats received 0.4 U/kg (subcutaneous) of IDeg and IGla-U300 on two different days, >1 wk apart. Exogenous insulin was measured and pharmacodynamic parameters were derived from glucose infusion rates during isoglycemic clamps and suppression of endogenous insulin. The Shapiro-Wilk test was used to assess normality, and normally distributed parameters were compared using paired t-tests. There was no difference between IDeg and IGla-U300 in onset, peak action, or total metabolic effect. On average, time to peak action (TPEAK) of IGla-U300 was 145 ± 114 min (95% confidence interval [CI] = 25-264) longer than TPEAK of IDeg (P = 0.03) and duration of action (TDUR) of IGla-U300 was 250 ± 173 min (95% CI = 68-432) longer than TDUR of IDeg (P = 0.02). The "flatness" of the time-action profile (as represented by the quotient of peak action/TDUR) was significantly greater for IGla-U300 compared with IDeg (P = 0.04). Overall, insulin concentration measurements concurred with findings from isoglycemic clamps. Based on these data, IDeg is not suitable for once-daily administration in cats. The efficacy of once-daily IGla-U300 in diabetic cats should be further investigated.

Pharmacokinetic and pharmacodynamic differences of new generation, longer-acting basal insulins: potential implications for clinical practice in type 2 diabetes.

The treatment of type 2 diabetes (T2D) is often complicated by factors such as patient co-morbidities, complex drug-drug interactions, and management of adverse events. In addition, some of these factors are highly dependent on the nature of the treatment regimen and the molecular and physical properties of the drugs being used to treat patients with this disease. This calls for a better understanding of how the properties of individual drugs affect the overall outcome for patients with diabetes. Clinical pharmacology studies to assess the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of new diabetes drugs play an important role in advancing our understanding of the interactions between a drug and the human body. Specific PK and PD techniques such as the glucose clamp test can be applied to assess the properties of drugs used for the treatment of diabetes. Basal insulin analogs are a common treatment option for the maintenance of glycemic control in patients with T2D. These drugs work by mimicking endogenous insulin secretion within the body and provide stable and prolonged insulin action to achieve optimal glucose levels. Insulin glargine 300 U/mL (Gla-300) and insulin degludec (IDeg) 100 U/mL and 200 U/mL represent a new generation of longer-acting basal insulins. These drugs demonstrate improved PK and PD properties compared with previous basal insulins, allowing them to more closely mimic physiological basal insulin secretion. Here we review the methods used to evaluate the PK and PD profiles of Gla-300 and IDeg and describe studies that have investigated the PK/PD properties of these drugs in type 1 diabetes. The aim of this review is to inform primary care physicians of the value and limitations of data from clinical pharmacology studies when prescribing these agents for the management of T2D.

The Relevance of Clinical Pharmacology Studies of Basal Insulins to Primary Care.

Pharmacokinetic (PK) and pharmacodynamic (PD) properties of drugs form the basis for the development of drugs used in everyday clinical practice, such as commonly used insulin products. PK measures the concentration of a drug in the body, and reflects the rates and amounts absorbed and processed. PD is the biologic effect of a drug in the body, including the time-course of when the biologic effect starts, peaks, and ends. While the determination of PK/PD parameters is important and foundational for the development of different insulin products, studies are often complex and can be difficult to translate into real-world clinical practice. In this roundtable, the speakers discuss PK/PD concepts, focusing on the differentiation of basal insulin analogs and their use in individualized diabetes therapy. First, the speakers discuss the euglycemic glucose clamp methodology-the standard technique for evaluating PK/PD of insulin-including how it is performed, what parameters it measures (and how they can be interpreted), and its limitations. Next, the speakers discuss how PK/PD impacts drug development, with particular focus on PK/PD studies used in the development of the second-generation basal insulin analogs insulin glargine 300 U/mL (Gla-300) and insulin degludec. Finally, the speakers discuss how PK/PD data translate into clinical practice, including the relationship between PK/PD and drug efficacy and safety, and how it influences dosing strategies, hypoglycemia risk, and patient education. Further, the speakers discuss how the PK/PD profile of basal insulins can inform primary care providers when selecting appropriate individualized therapy for patients.

Environmental effects of ambient temperature and relative humidity on insulin pharmacodynamics in adults with type 1 diabetes mellitus.

OBJECTIVE: This study aimed to explore the effects of ambient temperature and relative humidity on insulin pharmacodynamics in adults with type 1 diabetes. MATERIALS AND METHODS: A three-way, cross-over, randomised study was performed in adults with type 1 diabetes mellitus (n = 10). The pharmacodynamics profile of a single dose of short-acting insulin (insulin lispro) was investigated, using a controlled environmental chamber, under three environmental conditions: (a) temperature: 15°C and humidity: 10%; (b) temperature: 30°C and humidity: 10%; and (c) temperature: 30°C and humidity: 60%. A euglycaemic glucose clamp technique ensured constant blood glucose of 100 mg/dL (5.5 mmol/L). The following pharmacodynamic endpoints were calculated: maximum glucose infusion rate (GIRmax ), time to GIRmax (tGIRmax ), total area under the curve (AUC) for GIR from 0-6 hours (AUCGIR.0-6h ), and partial AUCs (AUCGIR.0-1h , AUCGIR.0-2h and AUCGIR.2-6h ). RESULTS: Higher temperature (30°C) under 10% fixed humidity conditions resulted in greater GIRmax (P = 0.04) and a later tGIR.max (P = 0.049) compared to lower temperature (15°C). Humidity did not affect any pharmacodynamic parameter. When the combined effects of temperature and humidity were explored, tGIR.max (P = 0.008) occurred earlier, with a lower late insulin pharmacodynamic effect (AUCGIR.2-6h ; P = 0.017) at a temperature of 15°C and humidity of 10% compared to a temperature of 30°C and humidity of 60%. CONCLUSIONS: High ambient temperature resulted in a greater insulin peak effect compared to low ambient temperature, with the contribution of high relative humidity apparent only at high ambient temperature. This suggests that patients with type 1 diabetes mellitus who are entering higher environmental temperatures, with or without high humidity, could experience more hypoglycaemic events.

Clinical relevance of pharmacokinetic and pharmacodynamic profiles of insulin degludec (100, 200 U/mL) and insulin glargine (100, 300 U/mL) - a review of evidence and clinical interpretation.

AIM: Second-generation basal insulin analogues (e.g. insulin degludec, insulin glargine 300 U/mL), were designed to further extend the duration of insulin action and reduce within-day and day-to-day variability, and consequently hypoglycaemia risk, versus earlier long-acting basal insulins. This review examines the pharmacokinetic/pharmacodynamic characteristics of insulin degludec (100, 200 U/mL) and insulin glargine (100, 300 U/mL), and their influence on clinical outcomes. METHODS: Available pharmacokinetic/pharmacodynamic publications comparing insulin degludec and insulin glargine were reviewed. RESULTS: Both insulin degludec and insulin glargine 300 U/mL have more prolonged and stable pharmacokinetic/pharmacodynamic profiles than the earlier basal insulin analogue, insulin glargine 100 U/mL. Insulin glargine 300 U/mL (0.4 U/kg, morning) showed a more stable pharmacodynamic profile (20% lower within-day variability [P = 0.047]) and more even 24-h distribution (over each 6-h quartile) than insulin degludec 100 U/mL, whereas the supratherapeutic 0.6 U/kg dose demonstrated a similar, albeit non-significant, trend. In contrast, a second clamp study indicated lower day-to-day variability in the 24-h glucose-lowering effect (variance ratio 3.70, P < 0.0001), and more even dosing over each 6-h quartile, with insulin degludec 200 U/mL versus insulin glargine 300 U/mL (0.4 U/kg, evening). Methodological differences and differences in bioequivalence that may explain these discrepancies are discussed. CONCLUSIONS: Compared with earlier insulin analogues, second-generation basal insulins have improved pharmacokinetic/pharmacodynamic profiles that translate into clinical benefits, primarily reduced nocturnal-hypoglycaemia risk. Additional head-to-head comparisons of insulin degludec and insulin glargine 300 U/mL at bioequivalent doses, utilising continuous glucose monitoring and/or real-world evidence, are required to elucidate the differences in their pharmacological and clinical profiles.

Comparison of the pharmacodynamics of protamine zinc insulin and insulin degludec and validation of the continuous glucose monitoring system iPro2 in healthy cats.

With the aim to improve current therapeutic and monitoring options for diabetic cats, the present study compared pharmacodynamic parameters of protamine zinc insulin (PZI) and insulin degludec and validated the continuous glucose monitoring system (CGMS) iPro2 with Sof-sensor and Enlite-sensor focusing on the low glycemic range. Three doses (0.1, 0.2 and 0.3IU/kg) of the two insulin preparations and the CGMS iPro2 with two different sensors were tested in six healthy cats. After each insulin administration, onset of action, time to glucose nadir and duration of action were calculated by measuring glucose concentrations with a portable blood glucose meter (PBGM). After sensor placement, paired PBGM and sensor glucose measurements were done and analytical and clinical accuracy were calculated according to the ISO 15197:2013 criteria. Onset of action, time to glucose nadir and glucose nadir were similar for both insulin formulations. Duration of action of insulin degludec was significantly longer than those of PZI at 0.1IU/kg (P=0.043) and 0.2IU/kg (P=0.043). Overall, 166/191 (87%) Sof-sensor measurements and 106/121 (88%) Enlite-sensor measurements met ISO criteria for analytical accuracy, and all sensor measurements fulfilled ISO criteria for clinical accuracy. Insulin degludec was well tolerated in healthy cats and showed longer duration of action than PZI. Further studies on the use of insulin degludec in diabetic cats might be recommended. Both sensors had good clinical accuracy, when used with the CGMS iPro2, but the analytical accuracy was below the minimum set by ISO 15197:2013.