Insulin Tregopil: An Ultra-Fast Oral Recombinant Human Insulin Analog: Preclinical and Clinical Development in Diabetes Mellitus.

Insulin therapy is indispensable for achieving glycemic control in all patients with type 1 diabetes mellitus and many patients with type 2 diabetes mellitus. Insulin injections are associated with negative connotations in patients owing to administration discomfort and adverse effects such as hypoglycemia and weight gain. Insulin administered orally can overcome these limitations by providing a convenient and effective mode of delivery with a potentially lower risk of hypoglycemia. Oral insulin mimics the physiologic process of insulin secretion, absorption into the portal circulation, and subsequent peripheral delivery, unlike the subcutaneous route that results in peripheral hyperinsulinemia. Insulin tregopil (IN-105), a new generation human recombinant insulin, methoxy (polyethylene glycol) hexanoyl human recombinant insulin, is developed by Biocon as an ultra-fast onset short-acting oral insulin analog. This recombinant oral insulin is a single short-chain amphiphilic oligomer modified with the covalent attachment of methoxy-triethylene-glycol-propionyl moiety at Lys-ß29-amino group of the B-chain via an amide linkage. Sodium caprate, an excipient in the insulin tregopil formulation, is a permeation enhancer that increases its absorption through the gastrointestinal tract. Also, meal composition has been shown to non-significantly affect its absorption. Several global randomized, controlled clinical trials have been conducted in type 1 and type 2 diabetes patients towards the clinical development of insulin tregopil. The formulation shows post-prandial glucose control that is more effective than placebo throughout the meal period; however, compared with an active comparator insulin aspart, the post-prandial control is more effective mainly in the early post-meal period. It shows a good safety profile with a lower incidence of clinically significant hypoglycemia. This review covers the overall clinical development of insulin tregopil establishing it as an ultra-fast onset, short-acting oral insulin analog for optimizing post-prandial glucose.

Weekly Icodec versus Daily Glargine U100 in Type 2 Diabetes without Previous Insulin.

BACKGROUND: Insulin icodec is an investigational once-weekly basal insulin analogue for diabetes management. METHODS: We conducted a 78-week randomized, open-label, treat-to-target phase 3a trial (including a 52-week main phase and a 26-week extension phase, plus a 5-week follow-up period) involving adults with type 2 diabetes (glycated hemoglobin level, 7 to 11%) who had not previously received insulin. Participants were randomly assigned in a 1:1 ratio to receive once-weekly insulin icodec or once-daily insulin glargine U100. The primary end point was the change in the glycated hemoglobin level from baseline to week 52; the confirmatory secondary end point was the percentage of time spent in the glycemic range of 70 to 180 mg per deciliter (3.9 to 10.0 mmol per liter) in weeks 48 to 52. Hypoglycemic episodes (from baseline to weeks 52 and 83) were recorded. RESULTS: Each group included 492 participants. Baseline characteristics were similar in the two groups. The mean reduction in the glycated hemoglobin level at 52 weeks was greater with icodec than with glargine U100 (from 8.50% to 6.93% with icodec [mean change, -1.55 percentage points] and from 8.44% to 7.12% with glargine U100 [mean change, -1.35 percentage points]); the estimated between-group difference (-0.19 percentage points; 95% confidence interval [CI], -0.36 to -0.03) confirmed the noninferiority (P<0.001) and superiority (P = 0.02) of icodec. The percentage of time spent in the glycemic range of 70 to 180 mg per deciliter was significantly higher with icodec than with glargine U100 (71.9% vs. 66.9%; estimated between-group difference, 4.27 percentage points [95% CI, 1.92 to 6.62]; P<0.001), which confirmed superiority. Rates of combined clinically significant or severe hypoglycemia were 0.30 events per person-year of exposure with icodec and 0.16 events per person-year of exposure with glargine U100 at week 52 (estimated rate ratio, 1.64; 95% CI, 0.98 to 2.75) and 0.30 and 0.16 events per person-year of exposure, respectively, at week 83 (estimated rate ratio, 1.63; 95% CI, 1.02 to 2.61). No new safety signals were identified, and incidences of adverse events were similar in the two groups. CONCLUSIONS: Glycemic control was significantly better with once-weekly insulin icodec than with once-daily insulin glargine U100. (Funded by Novo Nordisk; ONWARDS 1 ClinicalTrials.gov number, NCT04460885.).

Efficacy and safety of Tregopil, a novel, ultra-rapid acting oral prandial insulin analog, as part of a basal-bolus regimen in type 2 diabetes: a randomized, active-controlled phase 2/3 study.

BACKGROUND: Efficacy and safety of ultra-rapid acting oral prandial insulin Tregopil was compared with insulin aspart (IAsp) in patients with type 2 diabetes (T2D) on insulin glargine and metformin. RESEARCH DESIGN AND METHODS: In this open-label, active-controlled trial, patients with T2D, HbA1c ≥7%-≤9% and 2-h postprandial glucose (PPG) ≥180 mg/dL were randomized 1:1:1 to Tregopil (30 mg, n = 30; 45 mg, n = 31) and IAsp, n = 30. Primary outcome was change from baseline (CFB) in HbA1c at week 24. Secondary outcomes included PPG excursion (PPGE) and PPG assessed from standardized test meal (STM) and 9-point self-monitored blood glucose. RESULTS: The observed mean HbA1c did not improve at week 24 in Tregopil groups (30 mg [0.15%], 45 mg [0.22%] vs. a reduction in IAsp group [-0.77%]). Combined Tregopil group showed better 1-h PPGE control versus IAsp following STM (CFB, estimated treatment difference, 95% CI, -45.33 mg/dL [-71.91, -18.75], p = 0.001) and 1-h PPG trended toward better control. Tregopil showed lower PPGE at 15 min versus IAsp. Clinically significant hypoglycemia was lower with Tregopil versus. IAsp (rate ratio: 0.69). CONCLUSIONS: Tregopil demonstrated an ultrafast, short-duration prandial profile with good safety. While Tregopil's early postprandial effects were comparable to IAsp, its late postprandial effects were inferior. TRIAL REGISTRATION: The trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT03430856).

A chemoenzymatic strategy for site-selective functionalization of native peptides and proteins.

The emergence of new therapeutic modalities requires complementary tools for their efficient syntheses. Availability of methodologies for site-selective modification of biomolecules remains a long-standing challenge, given the inherent complexity and the presence of repeating residues that bear functional groups with similar reactivity profiles. We describe a bioconjugation strategy for modification of native peptides relying on high site selectivity conveyed by enzymes. We engineered penicillin G acylases to distinguish among free amino moieties of insulin (two at amino termini and an internal lysine) and manipulate cleavable phenylacetamide groups in a programmable manner to form protected insulin derivatives. This enables selective and specific chemical ligation to synthesize homogeneous bioconjugates, improving yield and purity compared to the existing methods, and generally opens avenues in the functionalization of native proteins to access biological probes or drugs.

Modifying insulin to improve performance.

A platform to enable precise modifications of insulin could improve drug functionality.

[Switching insulin degludec to insulin glulisine improved nocturnal hypoglycemia and ventricular arrythmia in an elderly type 1 diabetes patient with chronic heart failure: A case report].

The patient was 82-year-old man with type 1 diabetes mellitus. He had been using insulin degludec (IDeg) and insulin glulisine (IGlu) for treatment. He was admitted to our hospital due to diabetic ketoacidosis. As he started eating after recovery, we restarted intensive insulin therapy for glycemic control. Although he had eaten almost whole meals, his fasting blood glucose was extremely low, and the existence of nocturnal hypoglycemia was apparent. We reduced the dose and changed the injection time (evening→morning) of IDeg. We also stopped the evening IGlu injection; however, his nocturnal hypoglycemia did not improve. We decided to switch IDeg to insulin glargine U300 and to attach an intermittently scanned continuous glucose monitor (isCGM). His nocturnal hypoglycemia improved three days later. Since he had chronic heart failure and premature ventricular contractions, we used a Holter electrocardiogram to investigate the difference in arrythmia during hypoglycemia and non-hypoglycemia. As a result, the number of premature ventricular contractions was apparently high during hypoglycemia. In the present case, which involved an elderly patient with type 1 diabetes mellitus, chronic heart failure and nocturnal hypoglycemia, switching IDeg to insulin glargine U300 improved nocturnal hypoglycemia. IDeg differs from insulin glargine U300 in that it has a fatty acid side chain, which leads IDeg to combine with serum albumin. We thought that the increased level of free fatty acid due to hypoglycemia was competing against albumin combined IDeg, which increased free IDeg, and as a result, encouraged hypoglycemia.

Identifying signatures of proteolytic stability and monomeric propensity in O-glycosylated insulin using molecular simulation.

Insulin has been commonly adopted as a peptide drug to treat diabetes as it facilitates the uptake of glucose from the blood. The development of oral insulin remains elusive over decades owing to its susceptibility to the enzymes in the gastrointestinal tract and poor permeability through the intestinal epithelium upon dimerization. Recent experimental studies have revealed that certain O-linked glycosylation patterns could enhance insulin's proteolytic stability and reduce its dimerization propensity, but understanding such phenomena at the molecular level is still difficult. To address this challenge, we proposed and tested several structural determinants that could potentially influence insulin's proteolytic stability and dimerization propensity. We used these metrics to assess the properties of interest from [Formula: see text] aggregate molecular dynamics of each of 12 targeted insulin glyco-variants from multiple wild-type crystal structures. We found that glycan-involved hydrogen bonds and glycan-dimer occlusion were useful metrics predicting the proteolytic stability and dimerization propensity of insulin, respectively, as was in part the solvent-accessible surface area of proteolytic sites. However, other plausible metrics were not generally predictive. This work helps better explain how O-linked glycosylation influences the proteolytic stability and monomeric propensity of insulin, illuminating a path towards rational molecular design of insulin glycoforms.

Synthesis and Identification of Biologically Active Mono-Labelled FITC-Insulin Conjugate.

Fluorescently labelling proteins such as insulin have wide ranging applications in a pharmaceutical research and drug delivery. Human insulin (Actrapid®) was labelled with fluorescein isothiocyanate (FITC) and the synthesised conjugate identified using reverse phase high performance liquid chromatography (RP-HPLC) on a C18 column and a gradient method with mobile phase A containing 0.1% trifluoroacetic acid (TFA) in Millipore water and mobile phase B containing 90% Acetonitrile, 10% Millipore water and 0.1% TFA. Syntheses were carried out at varying reaction times between 4 and 20 h. Mono-labelled FITC-insulin conjugate was successfully synthesised with labelling at the B1 position on the insulin chain using a molar ratio of 2:1 (FITC:insulin) at a reaction time of 18 h and confirmed by electrospray mass spectroscopy. Reactions were studied across a pH range of 7-9.8 and the quantities switch from mono-labelled to di-labelled FITC-insulin conjugates at a reaction time of 2 h (2:1 molar ratio) at pH > 8. The conjugates isolated from the studies had biological activities in comparison to native insulin of 99.5% monoB1, 78% monoA1, 51% diA1B1 and 0.06% triA1B1B29 in HUVEC cells by examining AKT phosphorylation levels. MonoB1 FITC-insulin conjugate was also compared to native insulin by examining cell surface GLUT4 in C2C12 skeletal muscle cells. No significant difference in the cellular response was observed for monoB1 produced in-house compared to native insulin. Therefore mono-labelled FITC-insulin at the B1 position showed similar biological activity as native insulin and can potentially be used for future biomedical applications.

Basal insulin analogues in people with diabetes and chronic kidney disease.

BACKGROUND: Diabetic kidney disease is the leading cause of chronic kidney disease (CKD) and end-stage kidney disease (ESKD) worldwide. ESKD has a high prevalence in patients with diabetes mellitus (DM). CKD increases the chances of hypoglycaemia by different mechanisms, causes insulin resistance and a decrease in insulin metabolism. Both the "Kidney Disease: Improving Global Outcomes" (KDIGO) and "American Diabetes Association" (ADA) guidelines recommend the use of insulin as part of treatment, but the type of basal insulin is not specified. METHODS: We reviewed the literature to determine whether first- and second-generation basal insulins are effective and safe in CKD patients. We reviewed specific pivotal studies conducted by pharmaceutical laboratories, as well as independent studies. CONCLUSIONS: Basal insulins are safe and effective in patients with CKD and diabetes mellitus but we do not have specific studies. Given that CKD is one of the main complications of type 2 DM, and insulin specific treatment in the final stages, the absence of studies is striking. Real-life data are also important since trials such as pivotal studies do not fully represent actual patients. Treatment should be individualized until we have specific trials in this type of population.

Insulin smart drug delivery nanoparticles of aminophenylboronic acid-POSS molecule at neutral pH.

Self-regulated "smart" insulin administration system that mimic pancreatic endocrine function would be highly desirable for diabetes management. Here, a glucose-responsive continuous insulin delivery system is developed, where novel polyhedral oligosilsesquioxane (POSS) modified with 3-aminophenylboronic acid (APBA) were used to encapsulate insulin (insulin entrapment efficiency: 73.2%) to prepare a fast response, high stability, good distribution, and excellent biocompatible system. Due to the strong hydrophobicity of POSS, the POSS moiety is located at the core in aqueous solution and combines with the boronic group of APBA and the diol generated in PEG-insulin to form a nanomicelle structure, that is, nanoparticles naturally. Micelles self-assembled from these molecules possess glucose-responsiveness at varying glucose concentrations. The interaction of the PBA and diol containing insulin via boronate ester bond and its interchange with glucose was investigated by FT-IR, 1H NMR and XPS. Furthermore, the successful glucose-triggered release of insulin from the POSS-APBA micelles was investigated at neutral pH. A linear graph was plotted with the measured released insulin vs glucose concentrations, with a linear correlation coefficient (R2) value close to 1. Circular dichroism (CD) spectroscopy analysis was performed to measure insulin activity by comparing secondary structures of insulin, PEG-Insulin, and POSS-APBA@insulin. When confirming intracellular apoptosis signaling, cleaved caspase 3 and caspase 9 were not increased by 640 µg/ml POSS-APBA and POSS-APBA@insulin in HeLa, HDF and HUVE cells. Application in the biomedical field for controlled delivery of insulin appear to be promising.

Ultra-Fast Insulin-Pramlintide Co-Formulation for Improved Glucose Management in Diabetic Rats.

Dual-hormone replacement therapy with insulin and amylin in patients with type 1 diabetes has the potential to improve glucose management. Unfortunately, currently available formulations require burdensome separate injections at mealtimes and have disparate pharmacokinetics that do not mimic endogenous co-secretion. Here, amphiphilic acrylamide copolymers are used to create a stable co-formulation of monomeric insulin and amylin analogues (lispro and pramlintide) with synchronous pharmacokinetics and ultra-rapid action. The co-formulation is stable for over 16 h under stressed aging conditions, whereas commercial insulin lispro (Humalog) aggregates in 8 h. The faster pharmacokinetics of monomeric insulin in this co-formulation result in increased insulin-pramlintide overlap of 75 ± 6% compared to only 47 ± 7% for separate injections. The co-formulation results in similar delay in gastric emptying compared to pramlintide delivered separately. In a glucose challenge, in rats, the co-formulation reduces deviation from baseline glucose compared to insulin only, or separate insulin and pramlintide administrations. Further, comparison of interspecies pharmacokinetics of monomeric pramlintide suggests that pharmacokinetics observed for the co-formulation will be well preserved in future translation to humans. Together these results suggest that the co-formulation has the potential to improve mealtime glucose management and reduce patient burden in the treatment of diabetes.

Glucose-Sensitive Core-Cross-Linked Nanoparticles Constructed with Polyphosphoester Diblock Copolymer for Controlling Insulin Delivery.

This work aims to construct biocompatible, biodegradable core-cross-linked and insulin-loaded nanoparticles which are sensitive to glucose and release insulin via cleavage of the nanoparticles in a high-concentration blood glucose environment. First, a polyphosphoester-based diblock copolymer (PBYP-g-Gluc)-b-PEEP was prepared via ring-opening copolymerization (ROP) and the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) in which PBYP and PEEP represent the polymer segments from 2-(but-3-yn-1-yloxy)-2-oxo-1,3,2-dioxaphospholane and 2-ethoxy-2-oxo-1,3,2-dioxaphospholane, respectively, and Gluc comes from 2-azidoethyl-ß-d-glucopyranoside (Gluc-N3) that grafted with PBYP. The structure and molecular weight of the copolymer were characterized by 1H NMR, 31P NMR, GPC, FT-IR, and UV-vis measurements. The amphiphilic copolymer could self-assemble into core-shell uncore-cross-linked nanoparticles (UCCL NPs) in aqueous solutions and form core-cross-linked nanoparticles (CCL NPs) after adding cross-linking agent adipoylamidophenylboronic acid (AAPBA). Dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to study the self-assembly behavior of the two kinds of NPs and the effect of different Gluc group contents on the size of NPs further to verify the stability and glucose sensitivity of CCL NPs. The ability of NPs to load fluorescein isothiocyanate-labeled insulin (FITC-insulin) and their glucose-triggered release behavior were detected by a fluorescence spectrophotometer. The results of methyl thiazolyl tetrazolium (MTT) assay and hemolysis activity experiments showed that the CCL NPs had good biocompatibility. An in vivo hypoglycemic study has shown that FITC-insulin-loaded CCL NPs could reduce blood glucose and have a protective effect on hypoglycemia. This research provides a new method for constructing biodegradable and glucose-sensitive core-cross-linked nanomedicine carriers for controlled insulin release.

Insulin Analogues with Altered Insulin Receptor Isoform Binding Specificities and Enhanced Aggregation Stabilities.

Insulin is a lifesaver for millions of diabetic patients. There is a need for new insulin analogues with more physiological profiles and analogues that will be thermally more stable than human insulin. Here, we describe the chemical engineering of 48 insulin analogues that were designed to have changed binding specificities toward isoforms A and B of the insulin receptor (IR-A and IR-B). We systematically modified insulin at the C-terminus of the B-chain, at the N-terminus of the A-chain, and at A14 and A18 positions. We discovered an insulin analogue that has Cα-carboxyamidated Glu at B31 and Ala at B29 and that has a more than 3-fold-enhanced binding specificity in favor of the "metabolic" IR-B isoform. The analogue is more resistant to the formation of insulin fibrils at 37 °C and is also more efficient in mice than human insulin. Therefore, [AlaB29,GluB31,amideB31]-insulin may be interesting for further clinical evaluation.

Oligomerization of Pharmaceutically Relevant Insulin Analogues for Varying Concentration and Salinity Revealed by Small-Angle X-ray Scattering.

Two different insulin analogues, insulin degludec and lithocholyl insulin, were studied by small-angle X-ray scattering with respect to their self-assembly and interactions in solution at different concentrations of insulin and salt, NaCl. Very different behavior was observed for the two. Insulin degludec, linked to a hexadecanedioic acid, consistently formed di-hexamers, without any further oligomeric growth upon screening of electrostatic repulsions, indicating a stable di-hexamer unit without further oligomerization, as expected in the presence of phenol. The other insulin analogue, linked to the sterol lithocholic acid, formed n-hexamers with n ranging from 1 to 15, increasing with NaCl concentration and insulin concentration, indicating attractive forces in competition with the electrostatic repulsion and solution entropy. At the highest concentration of insulin and NaCl, a liquid crystal phase was observed, which has not previously been identified, featuring a quadratic structure organized into layers, which might hold interesting properties for pharmaceutical applications.

Icodec Advances the Prospect of Once-Weekly Insulin Injection.

Basal glucose control is commonly maintained by a single, once-daily administration of insulin through subcutaneous injection or a continuous pump-infusion. Insulin icodec, a novel ultralong-acting lipidated analog validates the concept of a once-weekly basal injection that is less burdensome, yet equally safe and efficacious as conventional once-daily treatment.

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.

Molecular Engineering of Insulin Icodec, the First Acylated Insulin Analog for Once-Weekly Administration in Humans.

Here, we describe the molecular engineering of insulin icodec to achieve a plasma half-life of 196 h in humans, suitable for once-weekly subcutaneously administration. Insulin icodec is based on re-engineering of the ultra-long oral basal insulin OI338 with a plasma half-life of 70 h in humans. This systematic re-engineering was accomplished by (1) further increasing the albumin binding by changing the fatty diacid from a 1,18-octadecanedioic acid (C18) to a 1,20-icosanedioic acid (C20) and (2) further reducing the insulin receptor affinity by the B16Tyr → His substitution. Insulin icodec was selected by screening for long intravenous plasma half-life in dogs while ensuring glucose-lowering potency following subcutaneous administration in rats. The ensuing structure-activity relationship resulted in insulin icodec. In phase-2 clinical trial, once-weekly insulin icodec provided safe and efficacious glycemic control comparable to once-daily insulin glargine in type 2 diabetes patients. The structure-activity relationship study leading to insulin icodec is presented here.

Large scale purification and characterization of A21 deamidated variant-most prominent post translational modification (PTM) for insulins which is also widely observed in insulins pharmaceutical manufacturing and storage.

Biopharmaceutical development demands appropriate understanding of product related variants, which are formed due to post-translational modification and during downstream processing. These variants can lead to low yield, reduced biological activity, and suboptimal product quality. In addition, these variants may undergo immune reactions, henceforth need to be appropriately controlled to ensure consistent product quality and patient safety. Deamidation of insulin is the most common post-translational modification occurring in insulin and insulin analogues. AsnA21 desamido variant is also the most prominent product variant formed during human insulin manufacturing process and/or during the storage. Often, this deamidated variant is used as an impurity standard during in-process and final product analysis in the QC system. However, purification of large quantity of purified deamidated material is always being challenging due to highly similar mass, ionic, hydrophobic properties, and high structural similarity of the variant compared to the parent product. Present work demonstrates the simplified and efficient scalable process for generation of AsnA21 deamidated variant in powder form with ~96% purity. The mixed-mode property of anion exchange resin PolyQuat was utilized to purify the deamidated impurity with high recovery. Subsequent reversed-phase high performance liquid chromatography (RP-HPLC) step was introduced for concentration of product in bind elute mode. Elution pool undergone isoelectric precipitation and lyophilisation. The lyophilized product allows users for convenient use of the deamidated impurity for intended purposes. Detailed characterization by Mass spectrometry revealed deamidation is at AsnA21 and further confirmed that, structural and functional characterization as well as the biological activity of isolated variant is equivalent to insulin.

Insulin and insulin analogs as antidiabetic therapy: A perspective from clinical trials.

The discovery of insulin in 1921 and the progress achieved in the ensuing century highlight the promise and challenge of biochemically modifying the molecule to achieve optimization of its delivery and therapeutic efficacy. Normal endogenous insulin secretion consists of a highly orchestrated physiologic loop wherein multiple metabolic signals trigger the pancreatic ß cells to secrete the precise amount of insulin into the portal system required to maintain euglycemia. Accordingly, in the treatment of diabetes, attempting to replicate this complex physiology with exogenous insulin therapy given subcutaneously presents a clinical challenge. In this context, recombinant DNA-based technology has enabled the development of insulin analogs that have been specifically designed to confer advantageous pharmacodynamic features that can better mimic endogenous insulin secretion. In this review, we discuss the development of the most widely available insulin preparations and provide evidence-based insight into their use in clinical practice.