Insulin therapy development beyond 100 years

Prandial Insulins: A Person-Centered Choice

PURPOSE OF REVIEW

Postprandial hyperglycemia, or elevated blood glucose after meals, is associated with the development and progression of various diabetes-related complications. Prandial insulins are designed to replicate the natural insulin release after meals and are highly effective in managing post-meal glucose spikes. Currently, different types of prandial insulins are available such as human regular insulin, rapid-acting analogs, ultra-rapid-acting analogs, and inhaled insulins. Knowledge about diverse landscape of prandial insulin will optimize glycemic management.

RECENT FINDINGS

Human regular insulin, identical to insulin produced by the human pancreas, has a slower onset and extended duration, potentially leading to post-meal hyperglycemia and later hypoglycemia. In contrast, rapid-acting analogs, such as lispro, aspart, and glulisine, are new insulin types with amino acid modifications that enhance their subcutaneous absorption, resulting in a faster onset and shorter action duration. Ultra-rapid analogs, like faster aspart and ultra-rapid lispro, offer even shorter onset of action, providing better meal-time flexibility. The Technosphere insulin offers an inhaled route for prandial insulin delivery. The prandial insulins can be incorporated into basal-bolus, basal plus, or prandial-only regimens or delivered through insulin pumps. Human regular insulin, aspart, lispro, and faster aspart are recommended for management of hyperglycemia during pregnancy. Ongoing research is focused on refining prandial insulin replacement and exploring newer delivery methods. The article provides a comprehensive overview of various prandial insulin options and their clinical applications in the management of diabetes.

Once-weekly insulins: a promising approach to reduce the treatment burden in people with diabetes

Despite the availability of new classes of glucose-lowering drugs that improve glycaemic levels and minimise long-term complications, at least 20-25% of people with type 2 diabetes require insulin therapy. Moreover, a substantial proportion of these individuals do not achieve adequate metabolic control following insulin initiation. This is due to several factors: therapeutic inertia, fear of hypoglycaemia and/or weight gain, poor communication, complexity of insulin titration, and the number of injections needed, with the associated reduced adherence to insulin therapy. Once-weekly insulins provide a unique opportunity to simplify basal insulin therapy and to allow good glycaemic control with a low risk of hypoglycaemia. Several approaches to developing a stable and effective once-weekly insulin have been proposed, but, to date, insulin icodec and basal insulin Fc (insulin efsitora alfa) are the only two formulations for which clinical studies have been reported. The results of Phase I and II studies emphasise both efficacy (in term of glucose levels) and potential risks and adverse events. Phase III studies involving insulin icodec are reassuring regarding the risk of hypoglycaemia compared with daily basal insulin analogues. Despite some concerns raised in ongoing clinical trials, the available data suggest that weekly insulins may also be an option for individuals with type 1 diabetes, especially when adherence is suboptimal. For the first time there is an opportunity to make an important breakthrough in basal insulin therapy, particularly in people with type 2 diabetes, and to improve not only the quality of life of people with diabetes, but also the practice of diabetologists.

Molecular engineering of insulin for recombinant expression in yeast

Since the first administration of insulin to a person with diabetes in 1922, scientific contributions from academia and industry have improved insulin therapy and access. The pharmaceutical need for insulin is now more than 40 tons annually, half of which is produced by recombinant secretory expression in Saccharomyces cerevisiae. We discuss how, in this yeast species, adaptation of insulin precursors by removable structural elements is pivotal for efficient secretory expression. The technologies reviewed have been implemented at industrial scale and are seminal for the supply of human insulin and insulin analogues to people with diabetes now and in the future. Engineering of a target protein with removable structural elements may provide a general approach to yield optimisation.

Materials and structure of polysaccharide-based delivery carriers for oral insulin: A review

Diabetes mellitus is a chronic metabolic disease that affects >500 million patients worldwide. Subcutaneous injection of insulin is the most effective treatment at present. However, regular needle injections will cause pain, inflammation, and other adverse consequences. In recent years, significant progress has been made in non-injectable insulin preparations. Oral administration is the best way of administration due to its simplicity, convenience, and good patient compliance. However, oral insulin delivery is hindered by many physiological barriers in the gastrointestinal tract, resulting in the low relative bioavailability of direct oral insulin delivery. To improve the relative bioavailability, a variety of insulin delivery vectors have been developed. Polysaccharides are used to achieve safe and effective insulin loading due to their excellent biocompatibility and protein affinity. The functional characteristics of polysaccharide-based delivery carriers, such as pH responsiveness, mucosal adhesion, and further functionalization modifications, enhance the gastrointestinal absorption and bioavailability of insulin. This paper reviews the materials and structures of oral insulin polysaccharide-based carriers, providing ideas for further improving the relative bioavailability of oral insulin.

Oral Delivery of Protein Drugs via Lysine Polymer-Based Nanoparticle Platforms

Oral delivery of proteins has opened a new perspective for the treatment of different diseases. However, advances of oral protein formulation are usually hindered by protein susceptibility and suboptimal absorption in the gastrointestinal tract (GIT). Polymeric nano drug delivery systems are considered revolutionary candidates to solve these issues, which can be preferably tunable against specific delivery challenges. Herein, a tailored family of lysine-based poly(ester amide)s (Lys-aaPEAs) is designed as a general oral protein delivery platform for efficient protein loading and protection from degradation. Insulin, as a model protein, can achieve effective internalization by epithelial cells and efficient transport across the intestinal epithelium layer into the systemic circulation, followed by controlled release in physiological environments. After the oral administration of insulin carried by Lys-aaPEAs with ornamental hyaluronic acid (HA), mice with type 1 diabetes mellitus showed an acceptable hypoglycemic effect with alleviated complications. A successful oral insulin delivery is associated with patient comfort and convenience and simultaneously avoids the risk of hypoglycemia compared with injections, which is of great feasibility for daily diabetes therapy. More importantly, this versatile Lys-aaPEAs polymeric library can be recognized as a universal vehicle for oral biomacromolecule delivery, providing more possibilities for treating various diseases.

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

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

Insulin biobetters and biosimilars in clinical practice

Insulin injections have never been an entirely satisfactory therapy, and as a result a continuing 'biobetter' technological cascade has driven changes in purity and manufacture, in structure and excipients, and in administration devices. The resulting deck of insulin preparations has to be matched by health-care teams and users with individual need. This latter is itself a complex ranging from ambulatory care in type 1 and type 2 diabetes, the topic generally addressed by guidelines and funding advice, to in-patient care and the newly diagnosed, plus secondary diabetes with very different effects on insulin need, through to co-morbidities and medications interfering with glucose metabolism. In this article the match of different clinical scenarios to the available insulins is discussed in the context of available evidence, quality guidelines, and diabetes best practice. Additionally the role of biosimilars of the insulin analogues is addressed, their limited but useful price advantage, and the management consequences of substitution for the originator product.

Long-Acting Insulin-Zwitterionic Polymer Conjugate Mitigates Hypoglycemia

Insulin, a main medication to control glycemia of type 1 and advanced type 2 diabetes, faces problems of a short half-life and poor stability during its clinical use. Zwitterionic polymer shows unique properties of antifouling and low immunogenicity. Here, we have synthesized a new insulin-zwitterionic polymer conjugate (INS-PMPC) through grafting-from strategy by controlled radical polymerization. Apart from showing excellent stability upon mechanical agitation, the resulting INS-PMPC conjugate provided over 20 h of glycemic control due to improved pharmacokinetics in diabetic mice with one single subcutaneous injection. Most importantly, this insulin-zwitterionic polymer conjugate significantly decreases the incidence of hypoglycemia.

Analysis of short-chain bioactive peptides by unified chromatography-electrospray ionization mass spectrometry. Part II. Comparison to reversed-phase ultra-high performance liquid chromatography

In the first part of this study, a unified chromatography (UC) analysis method, which is similar to supercritical fluid chromatography (SFC) but with wide mobile phase gradients of pressurized CO₂ and solvent, was developed to analyse short-chain peptides, with UV and mass spectrometry (MS) detection. In this second part, the method is compared to a reference reversed-phase ultra-high-performance liquid chromatography (RP-UHPLC) method, based on the analysis of 43 peptides, including 10 linear peptides and 33 cyclic ones. First, the orthogonality between the two methods was examined, based on the retention patterns. As the UC method was developed on a polar stationary phase (Ascentis Express OH5), the elution orders and selectivities were expected to be significantly different from RPLC on a non-polar stationary phase (ACQUITY CSH C18). Secondly, the success rate of the methods was examined, based on successful retention / elution of the peptides and the absence of observed co-elutions between the main peak and impurities. A successful analysis was obtained for 81% of the peptides in UC and 67% in RPLC. Thirdly, the performance of the methods for the intended application of impurity profiling of peptide drug candidates was assessed, based on the comparison of peak purities, the number of impurities detected and the thorough examination of impurity profiles. Excellent complementarity of the two methods for the specific task of impurity profiling, and for the separation of isomeric species was observed, with only one isomeric pair in this set remaining unresolved. The method sensitivity was however better with RPLC than UC. Finally, the operational costs in terms of solvent cost per analysis were the same between the two methods.

History of insulin treatment of pediatric patients with diabetes in Korea

The year 2021 is the centennial of insulin discovery. The discovery of insulin changes diabetes mellitus from a death sentence to a manageable disease. It became a historical turning point in the lives of people with diabetes. Since the first use of insulin in a patient in 1922, insulin and its analogs have been remarkable in saving the lives of people with diabetes. As insulin began to be used as a drug, it was introduced to, and used in Korea until now. This review briefly summarizes the history of insulin treatment in Korean children and adolescents with diabetes.