Immunogenicity of different brands of human insulin and rapid-acting insulin analogs in insulin-naïve children with type 1 diabetes

Characterization and root cause analysis of immunogenicity to pasotuxizumab (AMG 212), a prostate-specific membrane antigen-targeting bispecific T-cell engager therapy

Introduction

In oncology, anti-drug antibody (ADA) development that significantly curtails response durability has not historically risen to a level of concern. The relevance and attention ascribed to ADAs in oncology clinical studies have therefore been limited, and the extant literature on this subject scarce. In recent years, T cell engagers have gained preeminence within the prolific field of cancer immunotherapy. These drugs whose mode of action is expected to potently stimulate anti-tumor immunity, may potentially induce ADAs as an unintended corollary due to an overall augmentation of the immune response. ADA formation is therefore emerging as an important determinant in the successful clinical development of such biologics.

Methods

Here we describe the immunogenicity and its impact observed to pasotuxizumab (AMG 212), a prostate-specific membrane antigen (PSMA)-targeting bispecific T cell engager (BiTE®) molecule in NCT01723475, a first-in-human (FIH), multicenter, dose-escalation study in patients with metastatic castration-resistant prostate cancer (mCRPC). To explain the disparity in ADA incidence observed between the SC and CIV arms of the study, we interrogated other patient and product-specific factors that may have explained the difference beyond the route of administration.

Results

Treatment-emergent ADAs (TE-ADA) developed in all subjects treated with at least 1 cycle of AMG 212 in the subcutaneous (SC) arm. These ADAs were neutralizing and resulted in profound exposure loss that was associated with contemporaneous reversal of initial Prostate Surface Antigen (PSA) responses, curtailing durability of PSA response in patients. Pivoting from SC to a continuous intravenous (CIV) administration route remarkably yielded no subjects developing ADA to AMG 212. Through a series of stepwise functional assays, our investigation revealed that alongside a more historically immunogenic route of administration, non-tolerant T cell epitopes within the AMG 212 amino acid sequence were likely driving the high-titer, sustained ADA response observed in the SC arm.

Discussion

These mechanistic insights into the AMG 212 ADA response underscore the importance of performing preclinical immunogenicity risk evaluation as well as advocate for continuous iteration to better our biologics.

Influence of Insulin Receptor Single Nucleotide Polymorphisms on Glycaemic Control and Formation of Anti-Insulin Antibodies in Diabetes Mellitus

Single nucleotide polymorphisms (SNPs) in insulin and insulin receptor genes may influence the interaction between the two molecules, as may anti-insulin antibodies (IAs), commonly found in patients with type 1 diabetes mellitus (T1D) or type 2 diabetes mellitus (T2D) treated with exogenous insulin. We examined the impact of two SNPs in the human insulin gene (INS), rs3842752 and rs689, and two in the insulin receptor gene (INSR) rs2245649 and rs2229429, on disease susceptibility, glycaemic control, and IAs formation in 100 T1D patients and 101 T2D patients treated with insulin. 79 individuals without diabetes were typed as healthy controls. The minor alleles of rs3842752 and rs689 in INS protected against T1D (OR: 0.50, p = 0.01 and OR: 0.44; p = 0.002, respectively). The minor alleles of both rs2245649 and rs2229429 in INSR were risk factors for poor glycaemic control (HbA1c ≥ 80 mmol/mol) in T1D (OR: 5.35, p = 0.009 and OR: 3.10, p = 0.01, respectively). Surprisingly, the minor alleles of rs2245649 and rs2229429 in INSR associated strongly with the absence of IAs in T1D (OR = 0.28, p = 0.008 and OR = 0.30, p = 0.002, respectively). In conclusion, the minor alleles of the investigated INS SNPs protect against T1D, and the minor alleles of the investigated INSR SNPs are associated with poor glycaemic control and the absence of IAs in T1D.

The association between anti-insulin aspart antibodies and the pharmacokinetic and pharmacodynamic characteristics of fast-acting insulin aspart in children and adolescents with type 1 diabetes

BACKGROUND

Fast-acting insulin aspart (faster aspart) is a novel formulation of insulin aspart (IAsp) ensuring ultrafast absorption and effect.

AIM

To compare the pharmacokinetics between faster aspart and IAsp, based on free or total IAsp measurement, and investigate the association between anti-IAsp antibodies and faster aspart and IAsp pharmacological properties in children and adolescents with type 1 diabetes (T1D).

METHODS

In a randomized, two-period crossover trial, 12 children, 16 adolescents, and 15 adults (6-11, 12-17, and 18-64 years) received 0.2 U/kg double-blindsingle-dose subcutaneous faster aspart or IAsp followed by a standardized liquid meal test.

RESULTS

Across age groups, the pharmacokinetic profile was left-shifted including greater early exposure for faster aspart vs IAsp irrespective of free or total IAsp assay. Onset of appearance occurred 2.4 to 5.0 minutes (free) or 1.8 to 3.0 minutes (total) earlier for faster aspart vs IAsp (P < .05). Treatment ratios (faster aspart/IAsp) for 0 to 30 minutes IAsp exposure were 1.60 to 2.11 and 1.62 to 1.96, respectively (children, free: P = .062; otherwise P < .05). The ratio of free/total IAsp for overall exposure (AUC_IAsp,0-t ) was negatively associated with anti-IAsp antibody level across age. Pooling with a previous similar trial showed no clear association between anti-IAsp antibodies and meal test 1- or 2-hour postprandial glucose increment independent of age and insulin treatment (R² ≤ .070; P ≥ .17).

CONCLUSIONS

In children and adolescents with T1D, faster aspart provides ultrafast pharmacokinetics irrespective of free or total IAsp assay. Elevated anti-IAsp antibodies are associated with higher total IAsp concentration, but do not impact faster aspart and IAsp glucose-lowering effect.

RAPID DESENSITIZATION WITH INTRAVENOUS INSULIN IN A PATIENT WITH DIABETIC KETOACIDOSIS AND INSULIN ALLERGY

OBJECTIVE

We report a case of insulin desensitization in a patient with known allergy to multiple insulin preparations who presented with diabetic ketoacidosis (DKA).

METHODS

Clinical and laboratory data, and desensitization protocols are presented.

RESULTS

A 65-year-old woman with type 2 diabetes and a documented insulin allergy presented with severe DKA. She was managed initially with intravenous (IV) fluids, sodium bicarbonate, and hemodialysis. An intradermal skin test was positive for 0.01 units/mL of human regular insulin. A rapid desensitization protocol for IV human regular insulin was initiated after pretreatment with methylprednisolone, ranitidine, montelukast, and cetirizine. An initial dilution of 1 unit of insulin in 100,000 mL of 0.9% sodium chloride was started at 5 mL/hour IV. The dilution was increased at 60-minute intervals to 1 unit/10,000 mL, 1 unit/1,000 mL, 1 unit/100 mL, 1 unit/10 mL, then 1 unit/1 mL. The dose was then increased from 1 to 7 units/hour (0.1 units/kg body weight/hour). The anion gap closed after 24 hours, and overlapping desensitization was started for subcutaneous (SC) human regular insulin starting with 0.00001 units with a gradual increase to 7 units before meals and 6 units at bedtime over 5 days. There were no anaphylactic reactions to IV or SC insulin. She was discharged with human regular insulin SC 4 times daily, oral montelukast, cetirizine, diphenhydramine as needed, and an epinephrine pen. No allergic reactions were reported at follow-up visits.

CONCLUSION

Rapid insulin desensitization is possible to allow treatment of DKA with human regular insulin IV in patients with known insulin allergy.

Insulin Therapy and Diabetic Pregnancy

BACKGROUND

A good metabolic control before conception and throughout pregnancy with diabetes decreases the risk of short- and long-term adverse outcomes of the mothers and their offsprings. Insulin treatment remains the gold standard treatment recommended for any type of diabetes. New technologies including new insulins and insulin analogues, continuous subcutaneous insulin infusion without and with sensors, the low-glucose predictive suspension function, and closed-loop systems that persistently and automatically self-adjust according to patients' continuous glucose monitoring readings have expanded the offer to clinicians for achieving tight glucose control.

AREAS OF UNCERTAINTY

Unsafe effects of insulin and insulin analogues in pregnancy with diabetes could be linked with changes in insulin immunogenicity, teratogenicity, and mitogenicity. Second-generation insulin analogues need to be tested and proven. Effectiveness and safety of new insulin delivery systems in real life of diabetic women in pregnancy need further confirmations.

SOURCES

MEDLINE, EMBASE, Web of Science, Cochrane Library, randomized controlled trials, systematic review and meta-analysis, observational prospective and retrospective studies, case series reports for the most recent insulin analogues, published in English impacted journals, and consensus statements from scientific societies I excluded 60 from 221 papers as not suitable for the purpose of the subject.

RESULTS

Subcutaneous insulin infusion can be safely used during pregnancy and delivery of well-trained women. Sensors are increasingly accurate tools that improve the efficacy and safety of integrated systems' functioning. Continuous glucose monitoring provides metrics ("time in range" time in "hypoglycemia" and in "hyperglycemia," glucose variability, average glucose levels in different time intervals) used as a guide to diabetes management; these new metrics are object of discussion in special populations. Randomized controlled trials have shown that sensor-augmented pump therapy improves pregnancy outcomes in women with type 1 diabetes. Closed-loop insulin delivery provides better glycemic control than sensor-augmented pump therapy during pregnancy, before, and after delivery.

CONCLUSION

Second-generation insulin analogues and newer insulin infusion systems that automatically self-adjust according to patients continuous glucose monitor readings are important tools improving the treatment and quality of life of these women. Multi-institutional and disciplinary teams are working to develop and evaluate a pregnancy-specific artificial pancreas.

Healthy Donors Exhibit a CD4 T Cell Repertoire Specific to the Immunogenic Human Hormone H2-Relaxin before Injection

H2-relaxin (RLN2) is a two-chain peptide hormone structurally related to insulin with a therapeutic potential in multiple indications. However, multiple injections of human RLN2 induced anti-RLN2 Abs in patients, hampering its clinical development. As T cell activation is required to produce Abs, we wondered whether T cells specific for RLN2 might be already present in the human blood before any injection. We therefore quantified the RLN2-specific T cell repertoire using PBMCs collected from healthy donors. CD4 T cells were stimulated in multiple replicates by weekly rounds of stimulation by dendritic cells loaded with RLN2, and their specificity was assessed by IFN-γ ELISPOT. The number of specific T cell lines was used to estimate the frequency of circulating T cells. In vitro T cell response was demonstrated in 18 of the 23 healthy donors, leading to the generation of 70 independent RLN2-specific T cell lines. The mean frequency of RLN2-specific CD4 T cells was similar to that of T cells specific for known immunogenic therapeutic proteins. Using overlapping peptides, we identified multiple T cell epitopes hosted in the N-terminal parts of the α- and β-chains and common to multiple donors, in agreement with their capacity to bind to multiple HLA-DR molecules. Our results provide important clues to the immunogenicity of RLN2 and highlight the weak central immune tolerance induced against this self-hormone.

Antibody-Mediated Extreme Insulin Resistance: A Report of Three Cases

BACKGROUND

Type 2 diabetes mellitus is characterized by relative insulin deficiency and insulin resistance. Features suggesting severe insulin resistance include acanthosis nigricans, hyperandrogenism, weight loss, and recurrent hospital admissions for diabetic ketoacidosis. In rare circumstances, hyperglycemia persists despite administration of massive doses of insulin. In these cases, it is important to consider autoimmune etiologies for insulin resistance, such as type B insulin resistance and insulin antibody-mediated extreme insulin resistance, which carry high morbidity and mortality if untreated. Encouragingly, immunomodulatory regimens have recently been published that induce remission at high rates.

METHODS/RESULTS

We describe 3 cases of extreme insulin resistance mediated by anti-insulin receptor autoantibodies or insulin autoantibodies. All cases were effectively treated with an immunomodulatory regimen.

CONCLUSION

Although cases of extreme insulin resistance are rare, it is important to be aware of autoimmune causes, recognize suggestive signs and symptoms, and pursue appropriate diagnostic evaluation. Prompt treatment with immunomodulators is key to restoring euglycemia in patients with autoimmune etiologies of insulin resistance.

Exogenous insulin antibody syndrome (EIAS): a clinical syndrome associated with insulin antibodies induced by exogenous insulin in diabetic patients

Insulin has been used for diabetes therapy and has achieved significant therapeutic effect. In recent years, the use of purified and recombinant human insulin preparations has markedly reduced, but not completely suppressed, the incidence of insulin antibodies (IAs). IAs induced by exogenous insulin in diabetic patients is associated with clinical events, which is named exogenous insulin antibody syndrome (EIAS). The present review is based on our research and summarizes the characterization of IAs, the factors affecting IA development, the clinical significance of IAs and the treatments for EIAS.

Modeling Pharmacokinetic Profiles of Insulin Regimens to Enhance Understanding of Subcutaneous Insulin Regimens

Insulin pharmacokinetics following subcutaneous administration were modeled, simulated, and displayed through an interactive and user‐friendly interface to illustrate the time course of administered insulins frequently prescribed, providing a simple tool for clinicians through a straightforward visualization of insulin regimens. Pharmacokinetic data of insulin formulations with different onset and duration of action from several clinical studies, including insulin glargine, regular insulin, neutral protamine Hagedorn (NPH), insulin lispro, and premixed preparations of NPH with regular insulin (Mix 70/30), and insulin lispro protamine suspension with insulin lispro (Mix 50/50, Mix 75/25), were used to develop a predictive population pharmacokinetic model of insulins with consideration of factors such as insulin formulation, weight‐based dosing, body‐weight effect on volume of distribution, and administration time relative to meals, on the insulin time‐action profile. The model‐predicted insulin profile of each insulin was validated and confirmed to be comparable to observed data via an external validation method. Model‐based simulations of clinically relevant insulin‐dosing scenarios to cater to specific initial patient and prescribing conditions were then implemented with differential equations using the R statistical program (version 3.2.2). The R package Shiny was subsequently applied to build a web browser interface to execute and visualize the model simulation outputs. The application of insulin pharmacokinetic modeling enabled informative visualization of insulin time‐action profiles and provided an efficient and intuitive educational tool to quickly convey and interactively explore many insulin time‐action profiles to ease the understanding of insulin formulations in clinical practice.

20 Years of insulin lispro in pediatric type 1 diabetes: a review of available evidence

BACKGROUND

Insulin lispro, the first rapid-acting insulin analog, was developed 20 years ago and has been studied in multiple situations and various populations.

OBJECTIVE

To review the literature on the use of insulin lispro in children, adolescents, and young adults.

PATIENTS

Children, adolescents, and young adults with type-1-diabetes.

METHODS

One hundred and twenty-two relevant publications, identified by a systematic (MEDLINE) and manual literature search, were reviewed.

RESULTS

Multiple daily injection (MDI) treatment with insulin lispro or other rapid-acting insulins, mainly using neutral protamine Hagedorn (NPH) insulin as the basal component, was associated with reduced postprandial glucose excursions, similar or improved HbA1c levels, and similar or reduced risks of severe hypoglycemia when compared with regular human insulin across all age-groups. Continuous subcutaneous insulin infusion (CSII)-treatment with insulin lispro also showed similar or improved glycemic control vs. MDI- or other CSII-regimens across all age-groups, without increasing the rate of severe hypoglycemia. The other two more recently developed rapid-acting insulins (aspart, glulisine) demonstrated non-inferiority to lispro on HbA1c. Long-term observational studies and real-life experience indicate that the increasing use of optimized MDI- and CSII-regimens with insulin lispro was associated with improvements in overall glycemic control.

CONCLUSIONS

For almost 20 years, rapid-acting insulins, in particular insulin lispro as the first-in-class, have contributed to broadening the treatment options for the unique needs of pediatric patients with type-1-diabetes across all age-groups, and have enabled more physiological insulin administration. Now widely used, they have allowed pediatric patients to safely reach better glycemic control, with more flexibility in their daily lives.

Diagnosis of insulin autoimmune syndrome using polyethylene glycol precipitation and gel filtration chromatography with ex vivo insulin exchange

CONTEXT

Insulin-binding antibodies may produce severe dysglycaemia in insulin-naïve patients ('insulin autoimmune syndrome' (IAS) or Hirata disease), while rendering routine insulin assays unreliable.

OBJECTIVE

To assess the performance of clinically used insulin assays and an optimal analytical approach in the context of IAS.

DESIGN

Observational biochemical study of selected patients with hyperinsulinaemic hypoglycaemia.

PATIENTS

Three patients without diabetes with recurrent spontaneous hyperinsulinaemic hypoglycaemia and 'positive' insulin antibodies.

MEASUREMENTS

A panel of clinically used insulin assays (Siemens ADVIA^® Centaur, Siemens Immulite^® 2000, DiaSorin LIAISON^® XL, PE AutoDELFIA^® and the Beckman Coulter Access^® 2) were used before and after plasma dilution or polyethylene glycol (PEG) precipitation. Anti-insulin IgG antibodies were measured by Isletest^™ -IAA ELISA. Gel filtration chromatography (GFC) was undertaken with and without preincubation of plasma with exogenous insulin.

RESULTS

Dilution of IAS plasma with assay-specific buffer increased insulin recovery, supporting negative immunoassay interference by antibodies. PEG precipitation of IAS plasma decreased insulin recovery using all assays except the Immulite^® 2000. GFC discriminated high molecular weight and monomeric insulin, while ex vivo addition of exogenous insulin to plasma increased insulin bound to antibody, thereby improving the sensitivity of detection of insulin immunocomplexes.

CONCLUSIONS

Immunoprecipitation with PEG must be used with caution in screening for insulin-antibody complexes as results are assay dependent. GFC with addition of exogenous insulin can identify significant insulin immunocomplexes with enhanced sensitivity, with attendant greater clinical utility and avoidance of radiolabelled reagents.

Protamine-containing insulin but not analog insulin and duration of insulin use are risk factors for the production of insulin autoantibodies in insulin-treated patients with diabetes mellitus

Insulin autoantibodies can be produced by insulin injections but rarely cause severe side effects such as glucose instability and insulin allergy. We study the characteristics of insulin autoantibody-positive diabetic patients with a medical history of insulin therapy using single and multiple (adjusted for age, sex, type of diabetes) logistic regression analyses. Associations between insulin autoantibodies and age, sex, type of diabetes, HbA1c, and serum creatinine were not significant, but the association between insulin autoantibodies and duration of insulin use was significant. Unadjusted and adjusted odds ratios were 1.08 (1.02-1.14) and 1.07 (1.01-1.14), respectively. Unadjusted and adjusted odds ratios for protamine-containing insulin were 3.08 (1.49-6.34) and 4.27 (1.90-9.58), respectively. The adjusted odds ratios for premixed biphasic insulin and intermediate-acting insulin were 2.21 (1.03-4.73) and 2.35 (1.01-5.49), respectively. Associations between insulin autoantibodies and any insulin analog were not significant. These results suggest that protamine-containing insulin and duration of insulin use are risk factors for the production of insulin autoantibodies. If patients with poorly controlled diabetes have a history of protamine-containing insulin therapy over a long time, the appearance of insulin autoantibodies should be monitored.

Immunogenicity of subcutaneously administered therapeutic proteins--a mechanistic perspective

The administration of therapeutic proteins via the subcutaneous route (sc) is desired for compliance and convenience, but could be challenging due to perceived immunogenic potential or unwanted immune responses. There are clinical and preclinical data supporting as well as refuting the generalized notion that sc is more immunogenic. We provide a mechanistic perspective of immunogenicity of therapeutic proteins administered via the sc route and discuss strategies and opportunities for novel therapeutic approaches to mitigate immunogenicity.

Stabilization of bovine insulin against agitation-induced aggregation using RNA aptamers

Stabilization of monomeric insulin is a primary requirement for preserving the efficacy of the final formulation. Degraded and/or aggregated protein as well as the presence of any of the conventional excipients can result in immunogenic or anaphylactic reactions, and reduced bioavailability of the protein drug. The aim of this work was to select novel RNA-based stabilizers of bovine insulin which would recognize and bind to the monomeric protein and help retain its bioactivity. RNA aptamers were selected by an in vitro selection method. They were screened for their ability to inhibit insulin fibrillation using agitation as a stress condition. The in vitro activity of insulin was determined by phosphorylation of downstream proteins in the cell. In vivo bioactivity was determined in a diabetic rat model. RNA aptamers, which bound to insulin with very low dissociation constants and high specificity, were selected. These sequences were aligned and consensus regions were found. The RNA sequences had no effect on the signalling cascade initiated by insulin. The bioactivity of insulin, as measured by its ability to lower plasma glucose level in a diabetic rat model, also remained unchanged. RNA aptamers are a novel class of protein stabilizers which have the ability to disrupt protein-protein interactions and hence inhibit protein aggregation. Their non-toxic and non-immunogenic nature makes such formulations safe for use.

Safety of rapid-acting insulin analogs versus regular human insulin

Insulin is the most effective treatment for both type 1 and type 2 diabetes mellitus. There are several differences in the safety profiles of each type of insulin, including rapid-acting insulin analogs and regular human insulin. The pharmacokinetic and pharmacodynamic properties of those insulin types also differ, as do their safety parameters. Treatment with rapid-acting analogs results in less hypoglycemia overall and decreased frequency of both severe and nocturnal hypoglycemia. In addition, the more rapid onset and shorter duration of action of rapid-acting insulin analogs are associated with greater control of postprandial glucose than regular human insulin. This review will describe the similarities and differences between the safety profiles of rapid-acting insulin analogs.