Plasma exposure to insulin glargine and its metabolites M1 and M2 after subcutaneous injection of therapeutic and supratherapeutic doses of glargine in subjects with type 1 diabetes

The Modern Role of Basal Insulin in Advancing Therapy in People With Type 2 Diabetes

Insulin deficiency, often aggravated by insulin resistance, results in type 2 diabetes mellitus (T2DM). With the availability of glucagon-like peptide 1 receptor agonists and sodium-glucose cotransporter 2 inhibitors, basal insulin (BI) therapy is no longer the first-line option after lifestyle modification plus oral agents is insufficient. In contrast to BI, the newer medications require minor titration, lower hyperglycemia in a glucose-dependent manner, and reduce body weight. Importantly, the newer agents reduce cardiorenal events in the short term. Nonetheless, insulin therapy continues to play a key role in control of hyperglycemia and therefore long-term prevention of vascular complications. Its use is essential in many circumstances, including metabolic emergencies, new diabetes onset, latent autoimmune diabetes (LADA), pregnancy, and when other agents are less desirable due to comorbidities. BI is needed in the frequent condition of failure of other therapies to keep HbA1c to target and/or intolerance of them. There are several advantages to the combination of BI with the newer medications given their different but complementary mechanisms of action, primarily, the lower dose of each, improving adherence and outcomes while decreasing the side effects. Multiple choices for single or combination use can better meet the variety of clinical phenotypes in the heterogeneous T2DM population, using the tenets of precision medicine.

A comparative evaluation of bioequivalence of Gan & Lee glargine U300 and Toujeo® in Chinese healthy male participants

Background

To assess the bioequivalence between Gan & Lee (GL) glargine U300 and Toujeo® regarding pharmacokinetics (PK), pharmacodynamics (PD), and safety in Chinese healthy male participants.

Methods

A single-center, randomized, double-blind, single-dose, two-preparation, two-sequence, four-cycle repeated crossover design study was performed to compare GL glargine U300 and Toujeo® in 40 healthy participants. The primary PK endpoints were the area under the curve of glargine metabolites, M1 concentration from 0 to 24 hours (AUC0-24h), and the maximum glargine concentration within 24 hours post-dose (Cmax). The primary PD endpoints were the area under the glucose infusion rate (GIR) curve from 0 to 24 hours (AUCGIR.0-24h) and the maximum GIR within 24 hours post-dose (GIRmax).

Results

GL Glargine U300 demonstrated comparable PK parameters (AUC0-24h, Cmax, AUC0-12h, and AUC12-24h of M1) and PD responses [AUCGIR.0-24h, GIRmax, AUCGIR.0-12h, and AUCGIR.12-24h] to those of Toujeo®, as indicated by 90% confidence intervals ranging from 80% to 125%. No significant disparities in safety profiles were observed between the two treatment groups, and there were no reported instances of serious adverse events.

Conclusion

The PK, PD, and safety of GL glargine U300 were bioequivalent to that of Toujeo®.

Clinical trial registration

https://www.chinadrugtrials.org.cn/, identifier CTR20212419.

Assessment of circulating insulin using liquid chromatography-mass spectrometry during insulin glargine treatment in type 2 diabetes: Implications for estimating insulin sensitivity and β-cell function

AIM

To determine the potential impact of the cross-reactivity of insulin glargine U-100 and its metabolites on insulin sensitivity and β-cell measures in people with type 2 diabetes.

MATERIALS AND METHODS

Using liquid chromatography-mass spectrometry (LC-MS), we measured concentrations of endogenous insulin, glargine and its two metabolites (M1 and M2) in fasting and oral glucose tolerance test-stimulated plasma from 19 participants and fasting specimens from another 97 participants 12 months after randomization to receive the insulin glargine. The last dose of glargine was administered before 10:00 PM the night before testing. Insulin was also measured on these specimens using an immunoassay. We used fasting specimens to calculate insulin sensitivity (Homeostatic Model Assessment 2 [HOMA2]-S%; QUICKI index; PREDIM index) and β-cell function (HOMA2-B%). Using specimens following glucose ingestion, we calculated insulin sensitivity (Matsuda ISI[comp] index) and β-cell response (insulinogenic index [IGI], and total incremental insulin response [iAUC] insulin/glucose).

RESULTS

In plasma, glargine was metabolized to form the M1 and M2 metabolites that were quantifiable by LC-MS; however, the analogue and its metabolites cross-reacted by less than 100% in the insulin immunoassay. This incomplete cross-reactivity resulted in a systematic bias of fasting-based measures. By contrast, because M1 and M2 did not change following glucose ingestion, a bias was not observed for IGI and iAUC insulin/glucose.

CONCLUSIONS

Despite glargine metabolites being detected in the insulin immunoassay, dynamic insulin responses can be used to assess β-cell responsiveness. However, given the cross-reactivity of the glargine metabolites in the insulin immunoassay, fasting-based measures of insulin sensitivity and β-cell function are biased.

Pharmacokinetics and Safety of iGlarLixi in Healthy Chinese Participants: Results of a Phase 1 Randomized Study

INTRODUCTION

The Chinese Diabetes Society recommends basal insulin and glucagon-like peptide-1 receptor agonists as an add-on therapy to first-line oral antihyperglycemic drugs for people with type 2 diabetes (T2D). Fixed-ratio combination of insulin glargine 100 U/ml (iGlar) and lixisenatide (iGlarLixi) is known to improve glycemic control in adults with T2D. However, the pharmacokinetics of iGlarLixi has not been evaluated in Chinese participants. The present study evaluated pharmacokinetics and safety of two iGlarLixi (10 U/10 μg and 30 U/15 μg) doses following single subcutaneous administration in healthy Chinese participants.

METHODS

This was a Phase 1, single-center, open-label, parallel-group, randomized study in healthy Chinese adults who were randomized to receive a single dose of iGlarLixi with either 1:1 (10 U/10 μg) or 2:1 (30 U/15 μg) ratio of iGlar and lixisenatide. Primary objectives include assessment of pharmacokinetics of iGlar in iGlarLixi 30 U/15 μg group and the pharmacokinetics of lixisenatide in both the groups (iGlarLixi 10 U/10 μg and iGlarLixi 30 U/15 μg). Safety and tolerability were also assessed.

RESULTS

In iGlarLixi 30 U/15 μg group, iGlar concentrations were low and quantifiable in three of ten participants, while its main metabolite (M1) was quantifiable in all participants, reflecting rapid conversion of iGlar to M1. Median INS-t_max was 14.00 h for iGlar and 13.00 h post-dose for M1. Absorption of lixisenatide was similar in both dose groups with median t_max of 3.25 and 2.00 h post-dose in both groups. The exposure increase was dose proportionate with a 1.5-fold increase in the lixisenatide dose. Adverse events observed were consistent with those previously reported with iGlar or lixisenatide.

CONCLUSION

iGlarLixi administration resulted in early absorption of both iGlar and lixisenatide with a good tolerability profile in healthy Chinese participants. These results are consistent with the previously published data from other geographic regions.

TRIAL REGISTRATION

U1111-1194-9411.

Leveraging Clinical Pharmacology Data to Assess Biosimilarity and Interchangeability of Insulin Products

There is over a hundred years of clinical experience with insulin for the treatment of diabetes. The US Food and Drug Administration (FDA) approved the first insulin biosimilar interchangeable product in 2021 for improving glycemic control in adults and pediatric patients with type 1 diabetes mellitus and in adults with type 2 diabetes mellitus. Several recombinant insulin products are available in the United States, including the recently approved biosimilar insulins. The approval of the biosimilar insulin products was based on comparative analytical characterizations and comparative pharmacokinetic (PK) and pharmacodynamic (PD) data. The primary objective of this review is to discuss the scientific considerations in the demonstration of biosimilarity of a proposed insulin biosimilar to a reference product and the role of clinical pharmacology studies in the determination of biosimilarity and interchangeability. Euglycemic clamp studies are considered a "gold standard" for insulin PK and PD characterization and have been widely used to determine the time-action profiles of rapid-acting, intermediate-acting, and long-acting insulin products. Clinical pharmacology aspects of study design, including selection of appropriate dose, study population, PK, and PD end points, are presented. Finally, the role of clinical pharmacology studies in the interchangeability assessment of insulin and the regulatory pathways used for insulin and the experience with follow-on insulins and the two recently approved biosimilar insulin products is discussed.

Assessing the Structural and Functional Similarity of Insulin Glargine Biosimilars

BACKGROUND

A biosimilar product is expected to exhibit similar safety, efficacy, and quality as that of the approved reference product. Only a few reports of thorough evaluation of the quality of insulin glargine biosimilars are available in literature. Here, we examine the structural and functional similarity of biosimilars of insulin glargine, the first basal long-acting insulin analogue with respect to its innovator product (Lantus^® from Sanofi Aventis).

METHODS

Structural similarity was established using mass spectrometry, chromatographic, and spectroscopic techniques. Stability was compared by performing accelerated thermal stress studies. Functional similarity was established via in vitro assay.

RESULTS

Biosimilar 4 exhibited greater content of high molecular weight species (HMWs) (0.80%) and related substances (RS) (0.45±0.06%) vs others (HMWs of 0.04% and RS of 0.17%). Biosimilars 1 and 3 exhibited higher rate of impurity generation (0.78% and 0.73% per week, respectively), as compared with other drug products (0.02% to 0.43% per week). Furthermore, %aggregation at 14 days was found to statistically correlate (R²= 0.99, root mean square error (RMSE) = 0.095) with %aggregation at 0 day (linearly) and the number of months from expiry (nonlinearly), highlighting the overpowering impact of the latter.

CONCLUSIONS

While an overall structural and functional similarity was observed across insulin glargine biosimilars with respect to the innovator product, low amounts of product-related variants were seen in some biosimilars and these impact product stability. The %aggregation at 14 days exhibits statistical correlation with %aggregation at 0 day and the number of months from expiry. The order of biosimilarity was denoted as Lantus^®>Biosimilar 2>Biosimilar 4>Biosimilar 1>Biosimilar 3.

Identification, measurement, and evaluation of blood concentrations of insulin glargine and insulin lispro by UPLC-MS-MS in a dead body suspected of insulin overdose

Insulin preparations, which are drug treatments for diabetes, cause fatal hypoglycemia when an overdose is administered. Cases of homicide and suicide using these preparations have been reported and are of great forensic interest. However, there are few reports assessing the postmortem concentration of insulin preparations, and it is often difficult to determine the cause of death. In the present study, we report a case of a suspected insulin glargine and insulin lispro overdose for suicide. A woman in her 30s had a history of mental illness and diabetes. The day before her death, she reported to her boyfriend that she had taken large doses of insulin preparations and prescription drugs. An autopsy revealed no fatal injuries or lesions. Drug screening tests revealed several prescription drugs, none of which showed toxic concentrations. Analysis using LC-MS/MS detected insulin glargine in the peripheral and cardiac blood at 429 μU/mL and 1362 μU/mL, respectively, whereas insulin lispro was detected in both the peripheral and cardiac blood at levels below the lower limit of quantification (LLOQ; <50 μU/mL). The cause of death was considered likely to be hypoglycemia caused by an overdose of insulin glargine. Insulin glargine is rapidly metabolized after subcutaneous administration and is rarely detected in the blood when used at therapeutic doses. There are no other reports on the quantification of insulin glargine parent compounds in postmortem samples, and this case provides important data on postmortem blood concentrations of insulin glargine intoxication.

Insulin: evolution of insulin formulations and their application in clinical practice over 100 years

The first preparation of insulin extracted from a pancreas and made suitable for use in humans after purification was achieved 100 years ago in Toronto, an epoch-making achievement, which has ultimately provided a life-giving treatment for millions of people worldwide. The earliest animal-derived formulations were short-acting and contained many impurities that caused adverse reactions, thereby limiting their therapeutic potential. However, since then, insulin production and purification improved with enhanced technologies, along with a full understanding of the insulin molecule structure. The availability of radio-immunoassays contributed to the unravelling of the physiology of glucose homeostasis, ultimately leading to the adoption of rational models of insulin replacement. The introduction of recombinant DNA technologies has since resulted in the era of both rapid- and long-acting human insulin analogues administered via the subcutaneous route which better mimic the physiology of insulin secretion, leading to the modern basal-bolus regimen. These advances, in combination with improved education and technologies for glucose monitoring, enable people with diabetes to better meet individual glycaemic goals with a lower risk of hypoglycaemia. While the prevalence of diabetes continues to rise globally, it is important to recognise the scientific endeavour that has led to insulin remaining the cornerstone of diabetes management, on the centenary of its first successful use in humans.

Pharmacokinetic and pharmacodynamic similarity evaluation between an insulin glargine biosimilar product and Lantus® in healthy subjects: Pharmacokinetic parameters of both parent insulin glargine and M1 were used as endpoints

Insulin glargine is a long-acting insulin analog, which plays an important role in the treatment of diabetes mellitus. Biosimilar products of insulin glargine can provide patients with additional safe, high-quality, and potentially cost-effective options for treating diabetes. This article presents a randomized, double-blind, single-dose, two-treatment, four-period, replicate crossover, euglycemic clamp study which was designed to evaluate the PK and PD similarity between the recombinant insulin glargine developed by Wanbang (test) and Lantus® (reference) in healthy volunteers. Subjects received subcutaneous administration of the insulin glargine formulation (0.4 U/kg) on two occasions for the test and reference drug, respectively, and a 20% dextrose solution was infused at variable rate to clamp the blood glucose concentrations at 0.3 mmol/L below the subjects’ fasting glucose for 24 h. Taking advantage of the improved sensitivity of the bioanalytical method applied and the solution of the matrix stability problem, the parent insulin glargine was determined in the vast majority of plasma samples using a fully validated UHPLC-MS/MS method. The PK characteristics of the parent insulin glargine were revealed for the first time: after subcutaneous injection, concentrations of the parent insulin glargine increased to a relative high level within 3 h, and then, a relatively flat concentration–time profile lasting for at least 12 h post-dose was observed. For the first time, the pharmacokinetic parameters of the parent insulin glargine were used as endpoints for similarity evaluation, which complied with the regulatory guidance better and made the similarity conclusion more powerful. The ratios of geometric means of all PK and PD endpoints were close to 100.00%. For the PK endpoints (AUC0–24h, Cmax, AUC0–12h, and AUC12–24h of the parent insulin glargine and its metabolite M1), the 90% confidence intervals of geometric mean ratios of test to reference were entirely contained within 80.00%–125.00%. For the PD endpoints [AUCGIR(0–24h), GIRmax, AUCGIR(0–12h), and AUCGIR(12–24h)], the 95% confidence intervals of geometric mean ratios of test to reference were entirely contained within 80.00%–125.00%. Based on the above mentioned results, it can be concluded that the PK and PD characteristics of the biosimilar drug developed by Wanbang are similar to those of Lantus.

New Horizons: Next-Generation Insulin Analogues: Structural Principles and Clinical Goals

Design of "first-generation" insulin analogues over the past 3 decades has provided pharmaceutical formulations with tailored pharmacokinetic (PK) and pharmacodynamic (PD) properties. Application of a molecular tool kit-integrating protein sequence, chemical modification, and formulation-has thus led to improved prandial and basal formulations for the treatment of diabetes mellitus. Although PK/PD changes were modest in relation to prior formulations of human and animal insulins, significant clinical advantages in efficacy (mean glycemia) and safety (rates of hypoglycemia) were obtained. Continuing innovation is providing further improvements to achieve ultrarapid and ultrabasal analogue formulations in an effort to reduce glycemic variability and optimize time in range. Beyond such PK/PD metrics, next-generation insulin analogues seek to exploit therapeutic mechanisms: glucose-responsive ("smart") analogues, pathway-specific ("biased") analogues, and organ-targeted analogues. Smart insulin analogues and delivery systems promise to mitigate hypoglycemic risk, a critical barrier to glycemic control, whereas biased and organ-targeted insulin analogues may better recapitulate physiologic hormonal regulation. In each therapeutic class considerations of cost and stability will affect use and global distribution. This review highlights structural principles underlying next-generation design efforts, their respective biological rationale, and potential clinical applications.

Current State and Principles of Basal Insulin Therapy in Type 2 Diabetes

Treatment with basal insulins is a fundamental part of management in many patients with type 2 diabetes mellitus. Multiple management schemes may be indicated in these individuals, for example, the use of oral antihyperglycemic agents with basal insulins (basal-supported oral therapy) or the combinations of basal insulins with glucagon-like peptide-1 receptor agonists; each of these strategies makes it easier to achieve glycemic control goals. A basic knowledge of the physiology, pharmacodynamic and pharmacokinetic aspects of the different basal insulins is essential to achieve treatment goals and compliance. This review addresses the principles of management with basal insulins.

Molecular Modeling and Bioinformatics Analysis of Drug-Receptor Interactions in the System Formed by Glargine, Its Metabolite M1, the Insulin Receptor, and the IGF1 Receptor

Introduction

Insulin and insulin-like growth factor type 1 (IGF1) regulate multiple physiological functions by acting on the insulin receptor (IR) and insulin-like growth factor type 1 receptor (IGF1R). The insulin analog glargine differs from insulin in three residues (Gly^A21, Arg^B31, Arg^B32), and it is converted to metabolite M1 (lacks residues Arg^B31 and Arg^B32) by in vivo processing. It is known that activation of these receptors modulates pathways related to metabolism, cell division, and growth. Though, the structures and structural basis of the glargine interaction with these receptors are not known.

Aim

To generate predictive structural models, and to analyze the drug/receptor interactions in the system formed by glargine, its metabolite M1, IR, and IGF1R by using bioinformatics tools.

Methods

Ligand/receptor models were built by homology modeling using SWISSMODEL, and surface interactions were analyzed using Discovery Studio® Visualizer. Target and hetero target sequences and appropriate template structures were used for modeling.

Results

Our glargine/IR and metabolite M1/IR models showed an overall symmetric T-shaped conformation and full occupancy with four ligand molecules. The glargine/IR model revealed that the glargine residues Arg^B31 and Arg^B32 fit in a hydrophilic region formed by the α-chain C-terminal helix (αCT) and the cysteine-rich region (CR) domain of this receptor, close to the CR residues Arg270-Arg271-Gln272 and αCT residue Arg717. Regarding IGF1R, homologous ligand/receptor models were further built assuming that the receptor is in a symmetrical T-shaped conformation and is fully occupied with four ligand molecules, similar to what we described for IR. Our glargine/IGF1R model showed the interaction of the glargine residues Arg^B31 and Arg^B32 with Glu264 and Glu305 in the CR domain of IGF1R.

Conclusion

Using bioinformatics tools and predictive modeling, our study provides a better understanding of the glargine/receptor interactions.

Commemorating insulin's centennial: engineering insulin pharmacology towards physiology

The life-saving discovery of insulin in Toronto in 1921 is one of the most impactful achievements in medical history, at the time being hailed as a miracle treatment for diabetes. The insulin molecule itself, however, is poorly amenable as a pharmacological intervention, and the formidable challenge of optimizing insulin therapy has been ongoing for a century. We review early academic insights into insulin structure and its relation to self-association and receptor binding, as well as recombinant biotechnology, which have all been seminal for drug design. Recent developments have focused on combining genetic and chemical engineering with pharmaceutical optimization to generate ultra-rapid and ultra-long-acting, tissue-selective, or orally delivered insulin analogs. We further discuss these developments and propose that future scientific efforts in molecular engineering include realizing the dream of glucose-responsive insulin delivery.

Physicochemical and functional characterization of MYL-1501D, a proposed biosimilar to insulin glargine

Insulin glargine is a long-acting analogue of human insulin that has been used to manage hyperglycemia in patients with diabetes mellitus (DM) for nearly 20 years. Insulin glargine has a relatively constant concentration-time profile that mimics basal levels of insulin and allows for once-daily administration. MYL-1501D is a biosimilar insulin glargine designed to offer greater access of insulin glargine to patients, with comparable efficacy and safety to the marketed reference product. We conducted a comprehensive panel of studies based on a formal analysis of critical quality attributes to characterize the structural and functional properties of MYL-1501D and reference insulin glargine products available in the United States and European Union. MYL-1501D was comprehensively shown to have high similarity to the reference products in terms of protein structure, metabolic activity (both in vitro cell-based assays and in vivo rabbit bioassays), and in vitro cell-based assays for mitogenic activity. The structural analyses demonstrated that the primary protein sequence was identical, and secondary and tertiary structures are similar between the proposed biosimilar and the reference products. Insulin receptor binding affinity and phosphorylation studies also established analytical similarity. MYL-1501D demonstrated high similarity in different metabolic assays of glucose uptake, adipogenesis activity, and inhibition of stimulated lipolysis. Rabbit bioassay studies showed MYL-1501D and EU-approved insulin glargine are highly similar to US-licensed insulin glargine. These product quality studies show high similarity between MYL-1501D and licensed or approved insulin glargine products and suggest the potential of MYL-1501D as an alternative cost-effective treatment option for patients and clinicians.

The current schemes of insulin therapy: Pro and contra

Insulin regimens have been evolving for a century. The schemes used for type 1 (T1D) and type 2 (T2D) diabetes differ due to differences in pathophysiology but share important features. Insulin is required for both types of diabetes when other means of controlling glucose are insufficient. For T1D this requires multiple daily injections or continuous subcutaneous infusion assisted by CGM, whereas in early T2D basal insulin together with oral agents or GLP-1RA is usually effective. In both cases current schemes typically maintain HbA1c levels between 7 and 8%, a range that limits but does not eliminate the long-term complications of diabetes, but do not restore glycemic control to a fully protective level. Inability to control postprandial hyperglycemia without problematic weight gain and hypoglycemia is a leading obstacle in both T1D and long-duration T2D. A greater share of prandial dosing decisions will have to be provided by smart electronic systems. Further changes in the structure or formulation of insulin are of uncertain potential, but schemes including delivery of amylin, GLP-1, and glucagon show promise. More reliable access to insulins, delivery devices, and capable medical advisors will be needed to optimize replacement of this essential hormone.

The evolution of insulin therapy

Evolution in medicine is generally driven by clinical need, hand in hand with opportunities generated by novel chemical and mechanical engineering technologies. Since 1921 that has been a continuing paradigm for insulin therapy, some advances being a continual process, and others arising from external scientific or engineering developments. Purification of insulin preparations was an early issue, resolved in the 1970s, then challenged by the switch to manufacture in microorganisms. The nature of insulin was established serially, in 1928 as a polypeptide, in 1955 by amino acid sequence, and later by 3-dimensional structure (1969), laying foundations for understandings on routes of administration, and later the engineering of novel insulins. Insulin was the first, and remains the predominant, pharmaceutical therapy to benefit from scientific advances underlying the genetic code, and thus recombinant DNA technology. Advances in mechanical and chemical engineering have contributed to important changes in insulin delivery devices. Biological science, including both cellular mechanisms and whole organism physiology, has led to considerable understandings of clinical defects in insulin action, but currently has been disappointing in its applicability to the insulins available for clinical practice, something perhaps now changing. The pathways of these changes are reviewed here.

Detection of insulins in postmortem tissues: an optimized workflow based on immunopurification and LC-MS/HRMS detection

Diabetes is a worldwide disease in perpetual expansion. Type 1 and sometimes type 2 diabetic patients require daily human insulin (HI) or analog administration. Easy access to insulins for insulin-treated diabetics, their relatives, and medical professionals can enable abuse for suicidal or homicidal purpose. However, demonstrating insulin overdose in postmortem blood is challenging. Tissue analyses are contributive, as insulins can accumulate before death or undergo only limited degradation. The present study describes an assay for HI and synthetic analogs (lispro, aspart, glulisine, detemir and degludec, glargine and its main metabolite (M1)) in liver, kidney, muscle, and injection site samples. It is based on a 5-step sample preparation (reduction of tissue sample size, homogenization, extraction, concentration, and immunopurification) associated with liquid chromatography coupled to high-resolution mass spectrometry (LC-MS/HRMS). Selectivity and limit of detection (LOD) for all target analogs were assessed in the above matrices. LOD was determined at 25 ng/g for HI and for analogs except detemir and degludec, where LOD was 50 ng/g in kidney and injection site samples and 80 ng/g in the liver and muscle. The method was applied to13 forensic cases in which insulin use was suspected.

Glargine insulin loaded lipid nanoparticles: Oral delivery of liquid and solid oral dosage forms

BACKGROUND AND AIMS

The oral administration of insulin has so far been precluded by gastro-intestinal enzyme degradation and poor intestinal absorption. Preliminary evidence for peptide uptake by the gut has recently been obtained, by our research group, following the administration of nanostructured lipid-carrier suspensions loaded with glargine insulin in healthy animal models.

METHODS AND RESULTS

In this experimental study, glargine insulin-loaded nanostructured lipid carriers have been converted into solid oral dosage forms (tablets, capsules), that are more suitable for administration in humans and have prolonged shelf-life. The liquid and solid oral dosage forms were tested for glargine insulin uptake and glucose responsivity in healthy and streptozotocin-induced diabetic rats (6 animals in each group). A suitable composition gave redispersible solid oral dosage forms from glargine insulin-loaded carriers, using both spray-drying and freeze-drying. It was observed that the liquid and solid formulations had relevant hypoglycaemic effects in healthy rats, while only capsules were efficacious in diabetic rats; probably because of gut alterations in these animal models. Detected glargine insulinaemia was consistent with a glycaemic profile.

CONCLUSION

The formulations under study showed their potential as oral glucose-lowering agents, particularly when used as capsules. However, further study is needed to produce a useful orally-active insulin preparation.

Use of insulin glargine during pregnancy: A review

BACKGOUND AND AIMS

Hyperglycemia during pregnancy is increasing globally. Insulin therapy is considered the standard of care for its optimum management. Insulin glargine, in spite of widespread use in non-pregnant adults, lacks randomized controlled trial evidence as safe basal insulin during pregnancy. Aim of this review is to discuss major available evidences and recommendations on the use of insulin glargine during pregnancy.

METHODS

Evidences related to use of insulin glargine during pregnancy, including animal studies, placental transfer studies, case reports as well as observational studies were retrieved using PUBMED & Google scholar. Recommendations regarding use of insulin glargine during pregnancy by international and Indian organizations were reviewed.

RESULTS

Trans-placental transfer studies show that insulin glargine does not cross placenta when used at therapeutic concentrations. Although there are no randomized controlled trials on insulin glargine in pregnancy, it's use during pregnancy is not associated with any adverse maternal or neonatal outcomes as shown in many case reports and observational studies (both prospective and retrospective). It's use during pregnancy is hence considered safe by many organizations across the globe.

CONCLUSIONS

Insulin glargine can be continued safely during pregnancy in women who are already taking it prior to pregnancy and have achieved good glycemic control with it. However we require preferably randomized controlled trials or large prospective observational studies to establish it as first line or preferred basal insulin for management of hyperglycemia during pregnancy.

Equipotency of insulin glargine 300 and 100 U/mL with intravenous dosing but differential bioavailability with subcutaneous dosing in dogs

AIMS

Insulin glargine 300 U/mL (Gla-300) contains the same units versus glargine 100 U/mL (Gla-100) in three-fold lower volume, and higher subcutaneous (SC) doses are required in people with diabetes. To investigate blood glucose (BG) lowering potency, Gla-300 and Gla-100 were compared after intravenous (IV, for 4 h) and SC (for 24 h) injection in healthy Beagle dogs.

MATERIALS AND METHODS

The dose of 0.15 U/kg Gla-300 and Gla-100 was injected IV in 12 dogs. BG, C-peptide, glucagon and the active metabolite 21A-Gly-human insulin (M1; liquid chromatography-tandem mass spectrometry method) were measured. Twelve other dogs were studied after SC injection of 0.3 U/kg Gla-300 and Gla-100.

RESULTS

After IV injection, Gla-300 and Gla-100 were equally potent [BG_AUC_{0-4 h} ratio 1.01 (95% confidence interval, 0.94; 1.09)]. After SC injection, BG decreased slower and less with Gla-300. Similar metabolism of Gla-300 and Gla-100 to M1 occurred with IV dosing [M1_AUC_{0-1 h} ratio 0.99 (95% confidence interval, 0.82; 1.22)], but with SC dosing M1_C_max and AUC_0-24h were 44% and 17% lower; mean residency time and bioavailability were 32% longer and 50% lower, with Gla-300.

CONCLUSIONS

IV Gla-300 and Gla-100 have the equivalent of BG-lowering potency and M1 metabolism. SC Gla-300 has lower M1 bioavailability with a reduced BG-lowering effect and need for greater doses versus Gla-100.

Development and validation of a method for quantification of human insulin and its synthetic analogues in plasma and post-mortem sera by LC-MS/HRMS

Analysis of human insulin and its synthetic analogues is increasingly requested for clinical monitoring, for anti-doping purposes, but also for forensic cases. Indeed, insulin analogues may be abused for suicide or homicide - whence their forensic interest. Collection and storage conditions, as well as the phenomenon of degradation make post-mortem serum samples analytically challenging and consequently, the rate of exogenous insulin administration as cause of death is undoubtedly underestimated. However, with recent technological advances and the development of new extraction techniques particularly for anti-doping analyses, detection of insulins in post-mortem samples seems to be achievable. This study describes the first validated quantitative method for analysis human insulin and its six analogues (lispro, aspart, glulisine, glargine, detemir and degludec) in plasma and post-mortem sera. Various extraction processes, namely precipitation + solid phase extraction (SPE), filtration + SPE, precipitation + SPE + immunopurification, and filtration + immunopurification, were assessed to evaluate the lowest limit of detection for all target analogues. The selected sample preparation consists of filtration step followed by immunopurification extraction with an anti-body precoated ELISA plate for plasma. For post-mortem sera, the first step of precipitation was added to remove matrix interferences. The extracts were analyzed by ultra-high-performance liquid chromatography-high resolution mass spectrometry (LC-HRMS), interfaced by electrospray (ESI). The method was validated with respect linearity, precision, accuracy, recovery, matrix effect, dilution and carryover. The limit of quantification (LOQ) in plasma was 0.5 ng/mL for human insulin and rapid-acting insulins, 1.0 ng/mL for glargine, 2.5 ng/mL for degludec and 10 ng/mL for detemir. Two types of post-mortem sera were studied based on the post-mortem interval (PMI): inferior or superior to 48 h. The obtained LOQ were the same for each analogue, independent from the PMI: 1.0 ng/mL for human insulin and rapid-acting insulins, 1.0 ng/mL for glargine, 2.5 ng/mL for degludec and 10 ng/mL for detemir. At the LOQ level, for all insulins and all samples, accuracy was between 70 and 130% and precision inferior to 30%. The validated method was applied to five subjects participating in therapeutic monitoring of insulin and to seven post-mortem cases.

Detection of intact insulin analogues in post-mortem vitreous humour-Application to forensic toxicology casework

The application of proteomic techniques to forensic science widens the range of analytical capabilities available to forensic laboratories when answering complex toxicology problems. Currently, these techniques are underutilised in post-mortem toxicology because of the historic focus on smaller (<1,000 amu) drug molecules. Definitive confirmation of an insulin overdose by analysis of post-mortem biological matrices is rare and challenging, however can assist coronial investigations pertaining to accidental or intentional overdoses in both diabetic and nondiabetic populations. A semiautomated micro-solid phase extraction paired with mass spectrometry-based insulin methodology was developed and validated for routine use in a Forensic Coronial Toxicology Laboratory. This resulting work reports the first Australian cases where synthetic insulins were confirmed by mass spectrometry in the vitreous humour of Type 1 diabetics who intentionally or accidentally overdosed on their prescription medication glargine and aspart. The detection of glargine M1 in Case 1, aspart in Case 2 and glargine M1 was indicated in Case 3. This paper highlights advancements in forensic coronial toxicology and the promising potential of proteomic analysis in a forensic context.

Is insulin intoxication still the perfect crime? Analysis and interpretation of postmortem insulin: review and perspectives in forensic toxicology

Insulin is an anabolic hormone essential to glucose homeostasis. Insulin therapy, comprising human insulin (HI) or biosynthetic analogs, is critical for the management of type-1 diabetes and many of type-2 diabetes. However, medication error including non-adapted dose and confusion of insulin type, and misuse, such as massive self-administration or with criminal intent, can have lethal consequences. The aim of this paper is to review the state of knowledge of insulin analysis in biological samples and of the interpretation of insulin concentrations in the situation of insulin-related death investigations. Analytic aspects are considered, as quantification can be strongly impacted by methodology. Immunoanalysis, the historical technique, has a prominent role due to its sensitivity and ease of implementation. Recently, liquid chromatography coupled to mass spectrometry has provided indispensable selectivity in forensic contexts, distinguishing HI, analogs, and degradation products. We review the numerous antemortem (dose, associated pathology, injection-to-death interval, etc.) and postmortem parameters (in corpore degradation, in vitro degradation related to hemolysis, etc.) involved in the interpretation of insulin concentration. The interest and limitations of various alternative matrices providing a valuable complement to blood analysis are discussed. Vitreous humor is one of the most interesting, but the low diffusion of insulin in this matrix entails very low concentrations. Injection site analysis is relevant for identifying which type of insulin was administered. Muscle and renal cortex are matrices of particular interest, although additional studies are required. A table containing most case reports of fatal insulin poisoning published, with analytical data, completes this review. A logic diagram is proposed to highlight analytical issues and the main parameters to be considered for the interpretation of blood concentrations. Finally, it remains a challenge to provide reliable biological data and solid interpretation in the context of death related to insulin overdose. However, the progress of analytical tools is making the "perfect crime" ever more difficult to commit.

Are newer insulin analogues better for people with Type 1 diabetes?

Achieving optimal blood glucose control in Type 1 diabetes is a delicate balance between ensuring tight glycaemic control and achieving this without the expense of hypoglycaemia and weight gain, two major factors impacting quality of life. This is a real challenge for people with Type 1 diabetes and underpins many of the struggles they face in self-managing on a day-to-day basis. The main goals of insulin delivery are to try to simulate the physiology of β-cell insulin secretion as closely as possible and to overcome the challenges of peripheral insulin administration by achieving rapidity of onset with mealtime insulins and stability of the glucose-lowering effects of long-acting insulins. Since the early days of human insulin use, there have been many developments in insulin formulations that aim to achieve these goals as much as possible, thus contributing to better glycaemic control whilst minimizing hypoglycaemia. In the present review we discuss the currently available insulin analogues and the challenges of achieving glucose control using current analogues in those on multiple daily injections, and appraise the evidence base for newer-generation insulin analogues, such as insulin degludec, glargine U300, faster-acting insulin aspart and BioChaperone lispro. We also highlight new insulins in development and unmet needs in people with Type 1 diabetes.

Pharmacokinetic and pharmacodynamic bioequivalence of proposed biosimilar MYL-1501D with US and European insulin glargine formulations in patients with type 1 diabetes mellitus

AIMS

To report phase 1 bioequivalence results comparing MYL-1501D, US reference insulin glargine (US IG), and European reference insulin glargine (EU IG).

MATERIALS AND METHODS

The double-blind, randomized, three-way crossover study compared the pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of MYL-1501D, US IG and EU IG. In total, 114 patients with type 1 diabetes (T1DM) received 0.4 U/kg of each study treatment under automated euglycaemic clamp conditions. Insulin metabolite M1 concentrations, insulin glargine (IG) and glucose infusion rates (GIRs) were assessed over 30 hours. Primary PK endpoints were area under the serum IG concentration-time curve from 0 to 30 hours (AUCins.0-30h ) and maximum serum IG concentration (Cins.max ). Primary PD endpoints were area under the GIR-time curve from 0 to 30 hours (AUCGIR0-30h ) and maximum GIR (GIRmax ).

RESULTS

Bioequivalence among MYL-1501D, US IG and EU IG was demonstrated for the primary PK and PD endpoints. Least squares mean ratios were close to 1, and 90% confidence intervals were within 0.80 to 1.25. The PD GIR-time profiles were nearly superimposable. There were no noticeable differences in the safety profiles of the three treatments, and no serious adverse events were reported.

CONCLUSIONS

Equivalence with regard to PK and PD characteristics was shown among MYL-1501D, US IG and EU IG in patients with T1DM, and each treatment was well tolerated and safe.

Similar Breast Cancer Risk in Women Older Than 65 Years Initiating Glargine, Detemir, and NPH Insulins

OBJECTIVE

To assess whether initiation of insulin glargine (glargine), compared with initiation of NPH or insulin detemir (detemir), was associated with an increased risk of breast cancer in women with diabetes.

RESEARCH DESIGN AND METHODS

This was a retrospective new-user cohort study of female Medicare beneficiaries aged ≥65 years initiating glargine (203,159), detemir (67,012), or NPH (47,388) from September 2006 to September 2015, with follow-up through May 2017. Weighted Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% CIs for incidence of breast cancer according to ever use, cumulative duration of use, cumulative dose of insulin, length of follow-up time, and a combination of dose and length of follow-up time.

RESULTS

Ever use of glargine was not associated with an increased risk of breast cancer compared with NPH (HR 0.97; 95% CI 0.88-1.06) or detemir (HR 0.98; 95% CI 0.92-1.05). No increased risk was seen with glargine use compared with either NPH or detemir by duration of insulin use, length of follow-up, or cumulative dose of insulin. No increased risk of breast cancer was observed in medium- or high-dose glargine users compared with low-dose users.

CONCLUSIONS

Overall, glargine use was not associated with an increased risk of breast cancer compared with NPH or detemir in female Medicare beneficiaries.

Towards in vitro in vivo correlation for modified release subcutaneously administered insulins

Therapeutic proteins and peptides are mainly administrated by subcutaneous injection. In vitro release testing of subcutaneous injectables performed using methods that take the structure and environment of the subcutaneous tissue into account may improve predictability of the in vivo behavior and thereby facilitate establishment of in vitro in vivo correlations. The aim of the study was to develop a biopredictive flow-through in vitro release method with a gel-type matrix for subcutaneously administered formulations and to explore the possibility of establishing a level A in vitro in vivo correlation for selected insulin products. A novel gel-based flow-through method with the incorporation of an injection step was used to assess selected commercial insulin formulations with different duration of action (Actrapid®, Mixtard® 30, Insulatard®, Lantus®). The in vitro release method provided the correct rank ordering in relation to the in vivo performance. For the modified release insulins Insulatard® and Lantus®, an in vitro in vivo correlation using non-linear time scaling was established based on the in vitro release data and in vivo subcutaneous absorption data of the ¹²⁵I-labeled insulins taken from literature. Predicted absorption profiles were constructed using the in vitro in vivo correlation and subsequently converted into simulated plasma profiles. The approach taken may be of wider utility in characterizing injectables for subcutaneous administration.

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 (T_PEAK) of IGla-U300 was 145 ± 114 min (95% confidence interval [CI] = 25-264) longer than T_PEAK of IDeg (P = 0.03) and duration of action (T_DUR) of IGla-U300 was 250 ± 173 min (95% CI = 68-432) longer than T_DUR of IDeg (P = 0.02). The "flatness" of the time-action profile (as represented by the quotient of peak action/T_DUR) 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.

The quaternary structure of insulin glargine and glulisine under formulation conditions

The quaternary structures of insulin glargine and glulisine under formulation conditions and upon dilution using placebo or water were investigated using synchrotron small-angle X-ray scattering. Our results revealed that insulin glulisine in Apidra® is predominantly hexameric in solution with significant fractions of dodecamers and monomers. Upon dilution with placebo, this equilibrium shifts towards monomers. Insulin glargine in Lantus® and Toujeo® is present in a stable hexamer/dimer equilibrium, which is hardly affected by dilution with water down to 1 mg/ml insulin concentration. The results provide exclusive insight into the quaternary structure and thus the association/dissociation properties of the two insulin analogues in marketed formulations.

Modeling Subcutaneous Absorption of Long-Acting Insulin Glargine in Type 1 Diabetes

OBJECTIVE

Subcutaneous (sc) administration of long-acting insulin analogs is often employed in multiple daily injection (MDI) therapy of type 1 diabetes (T1D) to cover patient's basal insulin needs. Among these, insulin glargine 100 U/mL (Gla-100) and 300 U/mL (Gla-300) are formulations indicated for once daily sc administration in MDI therapy of T1D. A few semi-mechanistic models of sc absorption of insulin glargine have been proposed in the literature, but were not quantitatively assessed on a large dataset. The aim of this paper is to propose a model of sc absorption of insulin glargine able to describe the data and provide precise model parameters estimates with a clear physiological interpretation.

METHODS

Three candidate models were identified on a total of 47 and 77 insulin profiles of T1D subjects receiving a single or repeated sc administration of Gla-100 or Gla-300, respectively. Model comparison and selection were performed on the basis of their ability to describe the data and numerical identifiability.

RESULTS

The most parsimonious model is linear two-compartment and accounts for the insulin distribution between the two compartments after sc administration through parameter k. Between the two formulations, we report a lower fraction of insulin in the first versus second compartment (k = 86% versus 94% in Gla-100 versus Gla-300, p < 0.05), a lower dissolution rate from the first to the second compartment ([Formula: see text] versus 0.0008 min^-1 in Gla-100 versus Gla-300, p << 0.001), and a similar rate of insulin absorption from the second compartment to plasma ([Formula: see text] versus 0.0016 min^-1 in Gla-100 versus Gla-300, p = NS), in accordance with the mechanisms of insulin glargine protraction.

CONCLUSIONS

The proposed model is able to both accurately describe plasma insulin data after sc administration and precisely estimate physiologically plausible parameters.

SIGNIFICANCE

The model can be incorporated in simulation platforms potentially usable for optimizing basal insulin treatment strategies.

Insulin glargine affects the expression of Igf-1r, Insr, and Igf-1 genes in colon and liver of diabetic rats

Objective(s):

The mitogenic effect of the analogous insulin glargine is currently under debate since several clinical studies have raised the possibility that insulin glargine treatment has a carcinogenic potential in different tissues. This study aimed to evaluate the Igf-1r, Insr, and Igf-1 gene expression in colon and liver of streptozotocin-induced diabetic rats in response to insulin glargine, neutral protamine Hagedorn (NPH) insulin, and metformin treatments.

Materials and Methods:

Male Wistar rats were induced during one week with streptozotocin to develop Type 2 Diabetes (T2D) and then randomly distributed into four groups. T2D rats included in the first group received insulin glargine, the second group received NPH insulin, the third group received metformin; finally, untreated T2D rats were included as the control group. All groups were treated for seven days; after the treatment, tissue samples of liver and colon were obtained. Quantitative PCR (qPCR) was performed to analyze the Igf-1r, Insr and Igf-1 gene expression in each tissue sample.

Results:

The liver tissue showed overexpression of the Insr and Igf-1r genes (P>0.001) in rats treated with insulin glargine in comparison with the control group. Similar results were observed for the Insr gene (P>0.011) in colonic tissue of rats treated with insulin glargine.

Conclusion:

These observations demonstrate that insulin glargine promote an excess of insulin and IGF-1 receptors in STZ-induced diabetic rats, which could overstimulate the mitogenic signaling pathways.

A Review of Basal-Bolus Therapy Using Insulin Glargine and Insulin Lispro in the Management of Diabetes Mellitus

Basal-bolus therapy (BBT) refers to the combination of a long-acting basal insulin with a rapid-acting insulin at mealtimes. Basal insulin glargine 100 U/mL and prandial insulin lispro have been available for many years and there is a substantial evidence base to support the efficacy and safety of these agents when they are used in BBT or basal-plus therapy for patients with type 1 or type 2 diabetes mellitus (T1DM, T2DM). With the growing availability of alternative insulins for use in such regimens, it seems timely to review the data regarding BBT with insulin glargine 100 U/mL and insulin lispro. In patients with T1DM, BBT with insulin glargine plus insulin lispro provides similar or better glycemic control and leads to less nocturnal hypoglycemia compared to BBT using human insulin as the basal and/or prandial component, and generally provides similar glycemic control and rates of severe hypoglycemia to those achieved with insulin lispro administered by continuous subcutaneous insulin infusion (CSII). Studies evaluating BBT with insulin glargine plus insulin lispro in patients with T2DM also demonstrate the efficacy and safety of these insulins. Available data suggest that BBT with insulin glargine and insulin lispro provides similar levels of efficacy and safety in pediatric and adult populations with T1DM and in adult patients and those aged more than 65 years with T2DM. These insulin preparations also appear to be safe and effective for controlling T2DM in people of different ethnicities and in patients with T1DM or T2DM and comorbidities.

FUNDING

Eli Lilly and Company.

Single-dose euglycaemic clamp studies demonstrating pharmacokinetic and pharmacodynamic similarity between MK-1293 insulin glargine and originator insulin glargine (Lantus) in subjects with type 1 diabetes and healthy subjects

AIMS

MK-1293 is an insulin glargine that has an amino acid sequence identical to that of Lantus, the originator insulin glargine. Two euglycaemic clamp studies, 1 in subjects with type 1 diabetes (T1D) and 1 in healthy subjects, were conducted to demonstrate pharmacokinetic (PK) and pharmacodynamic (PD) similarity between MK-1293 and Lantus commercially procured in both the European Union (EU-Lantus) and the USA (US-Lantus).

MATERIALS AND METHODS

Both studies were single-dose, randomized, double-blind, single-centre, crossover studies with ≥7 days between dosing periods. A 2-treatment, 4-period replicate crossover study in T1D subjects (N = 76) compared the PK and PD of MK-1293 to EU-Lantus for 30 hours after dosing. A 3-period crossover study in healthy subjects (N = 109) compared the PK and PD of MK-1293, EU-Lantus and US-Lantus for 24 hours after dosing. In both studies, all subjects received single 0.4 units/kg subcutaneous doses of MK-1293 or Lantus in all dosing periods. Pharmacokinetic assessment was based on LC-MS/MS-based measurement of the major insulin glargine metabolite (M1) and PD was characterized using the euglycaemic clamp platform.

RESULTS

In both studies, pre-specified similarity criteria were met between MK-1293 and Lantus for comparison of PK (AUC0-24 and Cmax of M1) and PD (GIR-AUC0-24 , GIR-AUC0-12 , GIR-AUC12-24 , and GIRmax ) primary endpoints. All treatments were well tolerated.

CONCLUSION

Based on comparative assessment in both T1D and healthy subjects, it can be concluded that the PK and PD properties of MK-1293 are highly similar to those of Lantus. (ClinicalTrials.gov: NCT02059174).

Regulatory Forum Opinion Piece: Review-Toxicological Pathology Profile and Regulatory Expectations for Nonclinical Development of Insulins and Insulin Analogues

The toxicological profile of insulins is exclusively due to exaggerated pharmacology resulting in hypoglycemic findings. Insulin analogues displaying modifications and aimed at improving pharmacokinetics do not induce different toxicity. The main target is the brain displaying neuronal necrosis. Wallerian degeneration of nerves occurs rarely after severe hypoglycemia. These findings are of potential human relevance; nevertheless, these changes are induced in normoglycemic animals whereas diabetic patients suffer from hyperglycemia. Therefore, it is usually not difficult to achieve a therapeutic window for subsequent use in patients. Based upon this and in the absence of classical toxicity, there has been no scientific need for diabetic animal models. A greater challenge is the mitogenicity already inherent with regular insulin. Thus, the focus for preclinical safety evaluation of analogues is to demonstrate that modifications in regular insulin do not result in enhanced mitogenicity. The approaches used to assess the mitogenic potential of insulin analogues have changed over time driven by scientific progression and changes within the regulatory environment. Therefore, in vitro and in vivo evaluation of cell proliferation has become common practice, and to date there has been no evidence that the mitogenic potential of insulin analogues may be increased compared to regular insulin.

Clinical Pharmacokinetics and Pharmacodynamics of Insulin Glargine 300 U/mL

Concentrated insulin analogs have recently been approved and are available for clinical use in the management of diabetes mellitus. One new product is insulin glargine U-300 (Sanofi), a basal concentrated insulin of 300 U/mL. Several studies have been conducted and completed evaluating blood samples for the pharmacokinetics of insulin glargine U-300 and euglycemic clamp procedures for the pharmacodynamics. This concentrated insulin has a low within-day variability and high day-to-day reproducibility, allowing for a more constant and prolonged duration of action, compared with insulin glargine U-100 (100 U/mL). Insulin glargine U-300 is equally effective, when compared with insulin glargine U-100 for glycemic control in patients with type 1 and 2 diabetes mellitus. Insulin glargine U-300 has a similar efficacy profile to insulin glargine U-100 for glycemic control, yet with lower rates of nocturnal and severe hypoglycemia. Insulin glargine U-300 can be considered an acceptable basal insulin for patients with type 1 and 2 diabetes mellitus, and it has a potential role among patients who are naïve to insulin therapy or require titration of basal insulin. Titration of insulin glargine U-300 would result in less volume and a lower risk of hypoglycemia, compared with insulin glargine U-100. This article evaluates and summarizes the pharmacokinetics and pharmacodynamics of insulin glargine U-300, for patients with type 1 or 2 diabetes mellitus, and summarizes its application to clinical practice.

Insulin-like growth factor 1 receptor activation promotes mammary gland tumor development by increasing glycolysis and promoting biomass production

Background

The insulin-like growth factor 1 (IGF1) signaling axis plays a major role in tumorigenesis. In a previous experiment, we chronically treated mice with several agonists of the IGF1 receptor (IGF1R). We found that chronic treatment with insulin analogues with high affinity towards the IGF1R (IGF1 and X10) decreased the mammary gland tumor latency time in a p53^R270H/+WAPCre mouse model. Frequent injections with insulin analogues that only mildly activated the IGF1R in vivo (glargine and insulin) did not significantly decrease the tumor latency time in this mouse model.

Methods

Here, we performed next-generation RNA sequencing (40 million, 100 bp reads) on 50 mammary gland tumors to unravel the underlying mechanisms of IGF1R-promoted tumorigenesis. Mutational profiling of the individual tumors was performed to screen for treatment-specific mutations. The transcriptomic data were used to construct a support vector machine (SVM) classifier so that the phenotypic characteristics of tumors exposed to the different insulin analogue treatments could be predicted. For translational purposes, we ran the same classifiers on transcriptomic (micro-array) data of insulin analogue-exposed human breast cancer cell lines. Genome-scale metabolic modeling was performed with iMAT.

Results

We found that chronic X10 and IGF1 treatment resulted in tumors with an increased and sustained proliferative and invasive transcriptomic profile. Furthermore, a Warburg-like effect with increased glycolysis was observed in tumors of the X10/IGF1 groups and, to a lesser extent, also in glargine-induced tumors. A metabolic flux analysis revealed that this enhanced glycolysis programming in X10/IGF1 tumors was associated with increased biomass production programs. Although none of the treatments induced genetic instability or enhanced mutagenesis, mutations in Ezh2 and Hras were enriched in X10/IGF1 treatment tumors.

Conclusions

Overall, these data suggest that the decreased mammary gland tumor latency time caused by chronic IGF1R activation is related to modulation of tumor progression rather than increased tumor initiation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-017-0802-0) contains supplementary material, which is available to authorized users.

Pharmacokinetics and pharmacodynamics of insulin glargine 300 U/mL in the treatment of diabetes and their clinical relevance

INTRODUCTION

A more concentrated insulin glargine formulation, containing 300 U/mL (Gla-300) was approved in 2015 in the US and Europe for the treatment of diabetes mellitus in adults.

AREAS COVERED

This drug evaluation focuses on the pharmacokinetics (PK) and pharmacodynamics (PD) of Gla-300 from studies published up to May 2016. The clinical relevance of this new formulation will be addressed.

EXPERT OPINION

Gla-300 was developed to produce a flatter and more prolonged PK/PD profile compared with insulin glargine 100 U/mL (Gla-100) in order to maintain effective glycemic control and reduce the risk of hypoglycemia. Compared to Gla-100, Gla-300 achieves lower and delayed peak concentrations with a PK exposure that is more stable and evenly distributed across a 24-h dosing interval. As a consequence, Gla-300 results in a consistent glucose-lowering effect with less variability over a 24-h dosing interval, which translates to a reduction in the rate of hypoglycemia (particularly nocturnal events).

Non-metabolisable insulin glargine does not promote breast cancer growth in a mouse model of type 2 diabetes

AIMS/HYPOTHESIS

Previous epidemiological studies have reported a potential link between insulin analogues and breast cancer; however, a prospective randomised controlled trial showed neutral effects of insulin glargine on cancer risk. Insulin glargine is metabolised in vivo to an M1 metabolite. A question remains whether a subset of individuals with slower rates of glargine metabolism or who are on high doses could, theoretically, have an increased risk of cancer progression if a tumour is already present. In this study, we aimed to determine whether a non-metabolisable form of insulin glargine induced murine breast cancer growth.

METHODS

A mouse model of type 2 diabetes (MKR) was used for these studies. MKR mice were injected with two murine mammary cancer cell lines: Mvt-1 cells (derived from MMTV-c-Myc/Vegf tumours) and Met1 cells (derived from MMTV-polyoma virus middle T antigen tumours). Mice were treated with 25 U/kg per day of the long-acting insulin analogues, insulin glargine, insulin detemir, insulin degludec or non-metabolisable glargine, or vehicle.

RESULTS

No difference in tumour growth was seen in terms of tumour size after insulin glargine, detemir, degludec or vehicle injections. Non-metabolisable glargine did not increase tumour growth compared with insulin glargine or vehicle. Insulin glargine and non-metabolisable glargine led to insulin receptor phosphorylation in vivo rather than IGF-1 receptor phosphorylation.

CONCLUSIONS/INTERPRETATION

These results demonstrate that in a mouse model of type 2 diabetes, at high concentrations, basal insulin analogues and a non-metabolisable glargine analogue do not promote the progression of breast tumours.

Co-Managing Patients with Type 1 Diabetes and Cancer

The life expectancy of people with type 1 diabetes is improving and now approaches that of those without diabetes. As this population ages, a growing number will be diagnosed with and treated for cancer. Cancer treatments can drastically affect insulin requirement and glycemic control through multiple mechanisms including high doses of glucocorticoids and targeted therapies that directly interfere with cellular pathways involved in the action of insulin. Patients with cancer frequently also have alterations in gastrointestinal motility or appetite and require supplemental enteral or parenteral nutrition. Few studies have evaluated these patients directly, but data on patients with and without diabetes suggest that glycemic control may play a larger role in cancer outcomes than is often recognized. Collaboration between the treating oncologist and diabetologist allows people with diabetes to receive the most effective therapies for their cancers without undue risk of hypoglycemia or adverse outcomes due to hyperglycemia.

Effect of insulin analogues on phosphatidyl inositol-3 kinase/Akt signalling in INS-1 rat pancreatic derived β-cells

CONTEXT

Insulin analogues are largely used for the treatment of diabetic patients, but concerns have been raised about their mitogenic/anti-apoptotic potential. It is therefore important to evaluate these analogues in different cell systems.

OBJECTIVE

The aim of this work was to establish the pharmacological profiles of insulin analogues towards PI-3 kinase/Akt pathway in INS-1 β-pancreatic cells.

METHODS

Bioluminescence Resonance Energy Transfer (BRET), in cell western and caspase 3/7 assays, was used to study the effects of ligands.

RESULTS

Among the five analogues evaluated, only glargine stimulated PI-3 kinase/Akt pathway with higher efficiency than insulin, whereas glargine's metabolite M1 was less efficient. However, glargine did not show higher anti-apoptotic efficiency than insulin.

CONCLUSION

Glargine was more efficient than insulin for the activation of PI-3 kinase/Akt pathway, but not for the inhibition of caspase 3/7 activity. Moreover, glargine's metabolite M1 displayed lower efficiency than insulin towards PI-3 kinase/Akt activation and caspase 3/7 inhibition.

Comparison of the Pharmacokinetics and Pharmacodynamics of LY2963016 Insulin Glargine and EU- and US-Approved Versions of Lantus Insulin Glargine in Healthy Subjects: Three Randomized Euglycemic Clamp Studies

OBJECTIVE

LY2963016 (LY IGlar) and Lantus (IGlar) are insulin glargine products manufactured by distinct processes but with identical amino acid sequences. Three studies evaluated the pharmacokinetic (PK) and pharmacodynamic (PD) similarity of LY IGlar and the European Union- and US-approved versions of IGlar.

RESEARCH DESIGN AND METHODS

These were three single-site, randomized, double-blind, two-treatment, four-period, crossover, euglycemic clamp studies. In each study, fasted healthy subjects received 0.5 units/kg s.c. doses of two different insulin glargine products on two occasions each, following a randomized sequence. A ≥7-day washout period separated the doses. Blood samples were collected predose and up to 24 h postdose to assess PK; PD was assessed by a euglycemic clamp lasting up to 24 h.

RESULTS

A total of 211 subjects participated in the three studies. The PK (area under the curve [AUC]; maximum observed concentration [Cmax]) and PD (maximum glucose infusion rate [Rmax]; total glucose infusion during the clamp [Gtot]) were similar between LY IGlar and IGlar, with the ratios of geometric means ranging from 0.90 to 0.95 for PK parameters and from 0.91 to 0.99 for PD parameters across studies. In all cases, the 90% CIs for the ratios of geometric means were completely contained in the prespecified acceptance limits of 0.80-1.25. Adverse events were similar between treatments.

CONCLUSIONS

These studies demonstrated that the PK and PD properties of LY IGlar and IGlar were similar after single 0.5 units/kg s.c. doses in healthy subjects, contributing to the totality of evidence supporting similarity of these products.

Use of Insulin Lispro Protamine Suspension in Pregnancy

Maternal metabolism changes substantially during pregnancy, which poses numerous challenges to physicians managing pregnancy in women with diabetes. Insulin is the agent of choice for glycemic control in pregnant women with diabetes, and the insulin analogs are particularly interesting for use in pregnancy. These agents may reduce the risk of hypoglycemia and promote a more physiological glycemic profile than regular human insulin in pregnant women with type 1 (T1D), type 2 (T2D), or gestational (GDM) diabetes. However, there have been concerns regarding potential risk for crossing the placental barrier, mitogenic stimulation, teratogenicity, and embryotoxicity. Insulin lispro protamine suspension (ILPS), an intermediate- to long-acting insulin, has a stable and predictable pharmacological profile, and appears to have a favorable time–action profile and produce desirable basal and postprandial glycemic control. As the binding of insulin lispro is unaffected by the protamine molecule, ILPS is likely to have the same mitogenic and immunogenic potential as insulin lispro. Insulin lispro produces similar outcomes to regular insulin in pregnant women with T1D, T2D, or GDM, does not cross the placental barrier, and is considered a useful treatment option for pregnant women with diabetes. Clinical data support the usefulness of ILPS for basal insulin coverage in non-pregnant patients with T1D or T2D, and suggest that the optimal regimen, in terms of balance between efficacy and hypoglycemic risk, is a once-daily injection, especially in patients with T2D. Available data concerning use of ILPS in pregnant women are currently derived from retrospective analyses that involved, in total, >1200 pregnant women. These analyses suggest that ILPS is at least as safe and effective as neutral protamine Hagedorn insulin. Thus, available experimental and clinical data suggest that ILPS once daily is a safe and effective option for the management of diabetes in pregnant women.

Funding: Eli Lilly and Company.