How Can a Good Idea Fail? Basal Insulin Peglispro [LY2605541] for the Treatment of Type 2 Diabetes

Insulin Stabilization Designs for Enhanced Therapeutic Efficacy and Accessibility

ConspectusInsulin has remained indispensable in the treatment of diabetes since it was first discovered in 1921. Unlike small molecular drugs, insulin and other protein drugs are prone to degradation when exposed to elevated temperatures, mechanical agitation during transportation, and prolonged storage periods. Therefore, strict cold-chain management is crucial for the insulin supply, requiring significant resources, which can limit the access to insulin, particularly in low-income areas. Moreover, although insulin formulations have advanced tremendously in the last century, insulin treatment still imposes a challenging regimen and provides suboptimal outcomes for the majority of patients. There is an increasing focus on pursuing improved pharmacology, specifically on safer, more user-friendly insulin therapies that minimize the self-management burden. These challenges underscore the need for developing novel insulin formulations with improved stability that are compatible with advanced insulin therapy.Insulin stabilization can be achieved through either chemical modification of insulin or formulation component design. Inspired by insulin-like peptides from invertebrates, we have developed novel stable insulin analogs based on a fundamental understanding of the insulin receptor engagement for insulin bioactivity. We created a novel four-disulfide insulin analog with high aggregation stability and potency by introducing a fourth disulfide bond between a C-terminal extended insulin A-chain and residues near the C-terminus of the B-chain. In an effort to stabilize insulin in its monomeric state to develop ultrafast-acting insulin with rapid absorption upon injection, we have developed a series of structurally miniaturized yet fully active insulin analogs that do not form dimers due to the lack of the canonical B-chain C-terminal octapeptide. Additionally, our study provided strategies for expanding the scope of cucurbit[7]uril (CB[7])-assisted insulin stabilization by engineering safe and biodegradable CB[7]-zwitterionic polypeptide excipients. We also explored insulin N-terminal substitution methods to achieve pH-dependent insulin stabilization without prolonging the duration of action.This Account describes our exploration of engineering stable insulin analogs and formulation design strategies for stabilizing insulin in aqueous solutions. Beyond conventional stabilization strategies for insulin injections, the unmet challenges and recent innovations in insulin stabilization are discussed, addressing the growing demand for alternative, less invasive routes of insulin administration. Additionally, we aim to provide a thorough overview of insulin stabilization from the perspective of commercially available insulin drugs and common pharmaceutical engineering practices in the industry. We also highlight unresolved insulin stabilization challenges and ongoing research strategies. We anticipate that further emphasis on collective efforts of protein engineering, pharmaceutical formulation design, and drug delivery will inform the development of stable and advanced insulin therapy.

FGF21 agonists: An emerging therapeutic for metabolic dysfunction-associated steatohepatitis and beyond

The worldwide epidemics of obesity, hypertriglyceridemia, dyslipidaemia, type 2 diabetes, and metabolic dysfunction-associated steatotic liver disease (MASLD)/metabolic dysfunction-associated steatohepatitis (MASH) represent a major economic burden on healthcare systems. Patients with at-risk MASH, defined as MASH with moderate or significant fibrosis, are at higher risk of comorbidity/mortality, with a significant risk of cardiovascular diseases and/or major adverse liver outcomes. Despite a high unmet medical need, there is only one drug approved for MASH. Several drug candidates have reached the phase III development stage and could lead to several potential conditional drug approvals in the coming years. Within the armamentarium of future treatment options, FGF21 analogues hold an interesting position thanks to their pleiotropic effects in addition to their significant effect on both MASH resolution and fibrosis improvement. In this review, we summarise preclinical and clinical data from FGF21 analogues for MASH and explore additional potential therapeutic indications.

Insulin-Dendrimer Nanocomplex for Multi-Day Glucose-Responsive Therapy in Mice and Swine

The management of diabetes in a manner offering autonomous insulin therapy responsive to glucose-directed need, and moreover with a dosing schedule amenable to facile administration, remains an ongoing goal to improve the standard of care. While basal insulins with reduced dosing frequency, even once-weekly administration, are on the horizon, there is still no approved therapy that offers glucose-responsive insulin function. Herein, a nanoscale complex combining both electrostatic- and dynamic-covalent interactions between a synthetic dendrimer carrier and an insulin analogue modified with a high-affinity glucose-binding motif yields an injectable insulin depot affording both glucose-directed and long-lasting insulin availability. Following a single injection, it is even possible to control blood glucose for at least one week in diabetic swine subjected to daily oral glucose challenges. Measurements of serum insulin concentration in response to challenge show increases in insulin corresponding to elevated blood glucose levels, an uncommon finding even in preclinical work on glucose-responsive insulin. Accordingly, the subcutaneous nanocomplex that results from combining electrostatic- and dynamic-covalent interactions between a modified insulin and a synthetic dendrimer carrier affords a glucose-responsive insulin depot for week-long control following a single routine injection.

Insulin Therapy for the Management of Diabetes Mellitus: A Narrative Review of Innovative Treatment Strategies

The discovery of insulin was presented to the international medical community on May 3, 1922. Since then, insulin has become one of the most effective pharmacological agents used to treat type 1 and type 2 diabetes mellitus. However, the initiation and intensification of insulin therapy is often delayed in people living with type 2 diabetes due to numerous challenges associated with daily subcutaneous administration. Reducing the frequency of injections, using insulin pens instead of syringes and vials, simplifying treatment regimens, or administering insulin through alternative routes may help improve adherence to and persistence with insulin therapy among people living with diabetes. As the world commemorates the centennial of the commercialization of insulin, the aims of this article are to provide an overview of insulin therapy and to summarize clinically significant findings from phase 3 clinical trials evaluating less frequent dosing of insulin and the non-injectable administration of insulin.

Advances in buccal and oral delivery of insulin

Diabetes mellitus is a metabolic endocrine disease characterized by chronic hyperglycemia with disturbances in metabolic processes, such as those related to carbohydrates, fat, and protein. There are two main types of this disease: type 1 diabetes (T1D) and type 2 diabetes (T2D). Insulin therapy is pivotal to the management of diabetes. Over the last two decades, many routes of administration, including nasal, pulmonary, rectal, transdermal, buccal, and ocular, have been investigated. Nevertheless, subcutaneous parenteral administration is still the most common route for insulin therapy. To overcome poor bioavailability and the barriers to oral insulin absorption, novel approaches in the field of oral drug delivery and administration have been brought about by the coalescence of different branches of nanoscience and nanotechnology, such as nanomedicine, nano-biochemistry, and nano-pharmacy. Novel drug delivery systems, including nanoparticles, nano-platforms, and nanocarriers, have been suggested. The objective of this review is to provide an update on the various promising approaches that have been explored and evaluated for the safe and efficient oral and buccal administration of insulin.

Discrete, Chiral Polymer-Insulin Conjugates

Polymer conjugation has been widely used to improve the stability and pharmacokinetics of therapeutic biomacromolecules; however, conventional methods to generate such conjugates often use disperse and/or achiral polymers with limited functionality. The heterogeneity of such conjugates may lead to manufacturing variability, poorly controlled biological performance, and limited ability to optimize structure-property relationships. Here, using insulin as a model therapeutic polypeptide, we introduce a strategy for the synthesis of polymer-protein conjugates based on discrete, chiral polymers synthesized through iterative exponential growth (IEG). These conjugates eliminate manufacturing variables originating from polymer dispersity and poorly controlled absolute configuration. Moreover, they offer tunable molecular features, such as conformational rigidity, that can be modulated to impact protein function, enabling faster or longer-lasting blood glucose responses in diabetic mice when compared to PEGylated insulin and the commercial insulin variant Lantus. Furthermore, IEG-insulin conjugates showed no signs of decreased activity, immunogenicity, or toxicity following repeat dosing. This work represents a significant step toward the synthesis of precise synthetic polymer-biopolymer conjugates and reveals that fine tuning of synthetic polymer structure may be used to optimize such conjugates in the future.

Functionally selective signaling and broad metabolic benefits by novel insulin receptor partial agonists

Insulin analogs have been developed to treat diabetes with focus primarily on improving the time action profile without affecting ligand-receptor interaction or functional selectivity. As a result, inherent liabilities (e.g. hypoglycemia) of injectable insulin continue to limit the true therapeutic potential of related agents. Insulin dimers were synthesized to investigate whether partial agonism of the insulin receptor (IR) tyrosine kinase is achievable, and to explore the potential for tissue-selective systemic insulin pharmacology. The insulin dimers induced distinct IR conformational changes compared to native monomeric insulin and substrate phosphorylation assays demonstrated partial agonism. Structurally distinct dimers with differences in conjugation sites and linkers were prepared to deliver desirable IR partial agonist (IRPA). Systemic infusions of a B29-B29 dimer in vivo revealed sharp differences compared to native insulin. Suppression of hepatic glucose production and lipolysis were like that attained with regular insulin, albeit with a distinctly shallower dose-response. In contrast, there was highly attenuated stimulation of glucose uptake into muscle. Mechanistic studies indicated that IRPAs exploit tissue differences in receptor density and have additional distinctions pertaining to drug clearance and distribution. The hepato-adipose selective action of IRPAs is a potentially safer approach for treatment of diabetes.

One hundred years of insulin therapy

At the time of its first clinical application 100 years ago, insulin was presented as the cure for people with diabetes mellitus. That transpired to be an overstatement, yet insulin has proven to be the lifesaver for people with type 1 diabetes mellitus and an essential therapy for many with type 2 diabetes mellitus or other forms of diabetes mellitus. Since its discovery, insulin (a molecule of only 51 amino acids) has been the subject of pharmaceutical research and development that has paved the way for other protein-based therapies. From purified animal-extracted insulin and human insulin produced by genetically modified organisms to a spectrum of insulin analogues, pharmaceutical laboratories have strived to tailor the preparations to the needs of patients. Nonetheless, overall glycaemic control often remains poor as exogenous insulin is still not able to mimic the physiological insulin profile. Circumventing subcutaneous administration and the design of analogues with profiles that mimic that of physiological insulin are ongoing areas of research. Novel concepts, such as once-weekly insulins or glucose-dependent and oral insulins, are on the horizon but their real-world effectiveness still needs to be proven. Until a true cure for type 1 diabetes mellitus is found and the therapeutic arsenal for other forms of diabetes mellitus is expanded, insulin will remain central in the treatment of many people living with diabetes mellitus.

Efficacy and safety of 28-day treatment with oral insulin (ORMD-0801) in patients with type 2 diabetes: A randomized, placebo-controlled trial

AIM

To assess the safety and efficacy of oral insulin (ORMD-0801) in patients with type 2 diabetes (T2D).

MATERIALS AND METHODS

After a 2-week washout of other medications, adult metformin-treated patients with T2D were randomized to receive placebo or 16 or 24 mg ORMD-0801, once daily, at bedtime, for 28 days. The mean change from baseline weighted mean night-time glucose levels was determined from 2 nights of continuous glucose monitoring (CGM) recordings during the placebo run-in and last week of treatment.

RESULTS

In total, 188 patients (HbA1c: 7.82% ± 0.88% [placebo] and 8.08% ± 1.11% [pooled ORMD-0801 group]) were enrolled. In the placebo group, mean night-time CGM increased from baseline by 13.7 ± 26.1 mg/dL, whereas the increase was significantly smaller in the pooled ORMD-0801 group (1.7 ± 23.5 mg/dL, P = .0120). Glycaemic control variables (24-hour, fasting and daytime CGM glucose) also displayed smaller increases with ORMD-0801 versus placebo. Change from baseline HbA1c was -0.01% in the pooled ORMD-0801 group versus +0.20% in the placebo group (P = .0149). ORMD-0801 was well tolerated, with similar adverse event and hypoglycaemia rates as placebo.

CONCLUSIONS

In patients with T2D, bedtime ORMD-0801 curbed increases in night-time glycaemia, 24-hour glycaemia and HbA1c, without increasing the risk of hypoglycaemia or safety events compared with the control arm.

Brain insulin signalling in metabolic homeostasis and disease

Insulin signalling in the central nervous system regulates energy homeostasis by controlling metabolism in several organs and by coordinating organ crosstalk. Studies performed in rodents, non-human primates and humans over more than five decades using intracerebroventricular, direct hypothalamic or intranasal application of insulin provide evidence that brain insulin action might reduce food intake and, more importantly, regulates energy homeostasis by orchestrating nutrient partitioning. This Review discusses the metabolic pathways that are under the control of brain insulin action and explains how brain insulin resistance contributes to metabolic disease in obesity, the metabolic syndrome and type 2 diabetes mellitus.

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.

Efficacy and safety of PEGylated exenatide injection (PB-119) in treatment-naive type 2 diabetes mellitus patients: a Phase II randomised, double-blind, parallel, placebo-controlled study

AIMS/HYPOTHESIS

Glucagon-like peptide 1 receptor agonists (GLP-1 RA) such as exenatide are used as monotherapy and add-on therapy for maintaining glycaemic control in patients with type 2 diabetes mellitus. The current study investigated the safety and efficacy of once-weekly PB-119, a PEGylated exenatide injection, in treatment-naive patients with type 2 diabetes.

METHODS

In this Phase II, randomised, placebo-controlled, double-blind study, we randomly assigned treatment-naive Chinese patients with type 2 diabetes in a 1:1:1:1 ratio to receive subcutaneous placebo or one of three subcutaneous doses of PB-119 (75, 150, and 200 μg) for 12 weeks. The primary endpoint was the change in HbA_1c from baseline to week 12, and other endpoints were fasting plasma glucose, 2 h postprandial glucose (PPG), and proportion of patients with HbA_1c < 53 mmol/mol (<7.0%) and ≤48 mmol/mol (≤6.5%) at 2, 4, 8 and 12 weeks of treatment. Safety was assessed in all patients who received at least one dose of study drug.

RESULTS

We randomly assigned 251 patients to one of the four treatment groups (n = 62 in placebo and 63 each in PB-119 75 μg, 150 μg and 200 μg groups). At the end of 12 weeks, mean differences in HbA_1c in the treatment groups were -7.76 mmol/mol (95% CI -9.23, -4.63, p < 0.001) (-0.72%, 95% CI -1.01, -0.43), -12.89 mmol/mol (95% CI -16.05, -9.72, p < 0.001) (-1.18%, 95% CI -1.47, -0.89) and -11.14 mmol/mol (95% CI -14.19, -7.97, p <0 .001) (-1.02%, 95% CI -1.30, -0.73) in the 75 μg, 150 μg and 200 μg PB-119 groups, respectively, compared with that in the placebo group after adjusting for baseline HbA_1c. Similar results were also observed for other efficacy endpoints across different time points. There was no incidence of treatment-emergent serious adverse event, severe hypoglycaemia or death.

CONCLUSIONS/INTERPRETATION

All tested PB-119 doses had superior efficacy compared with placebo and were safe and well tolerated over 12 weeks in treatment-naive Chinese patients with type 2 diabetes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03520972 FUNDING: The study was funded by National Major Scientific and Technological Special Project for Significant New Drugs Development and PegBio.

The promising future of insulin therapy in diabetes mellitus

The first therapeutic use of insulin by Frederick Banting and Charles Best in 1921 revolutionized the management of type 1 diabetes and considerably changed the lives of many patients with other types of diabetes. In the past 100 years, significant pharmacological advances took place in the field of insulin therapy, bringing closer the goal of optimal glycemic control along with decreased diabetes-related complications. Despite these developments, several challenges remain, such as increasing treatment flexibility, reducing iatrogenic hypoglycemia, and optimizing patient quality of life. Ongoing innovations in insulin therapy (e.g., new insulin analogs, alternative routes of insulin administration, and closed-loop technology) endeavor to overcome these hurdles and change the landscape of diabetes mellitus management. This report highlights recent advances made in the field of insulin therapy and discusses future perspectives.

Minimising hypoglycaemia in the real world: the challenge of insulin

Insulin therapy has been a life saver for people with type 1 diabetes and has been an essential tool in the therapy of people with type 2 diabetes, but the risk for hypoglycaemia has been a major hurdle to achieving good glycaemic control for most. Insulin analogues, the availability of novel technologies for the administration of insulin, like insulin pumps, and, in particular, tools to measure glucose levels, evolving from capillary measurements to continuous glucose monitoring, have revolutionised the way in which people living with diabetes use insulin. Novel insulin concepts, like once-weekly or oral insulin administration, will have to demonstrate safety on the side of hypoglycaemia before they will be able to move into the clinic.

Enzymes and biopolymers. The opportunity for the smart design of molecular delivery systems

Enzymes exhibit a tremendous potential due to the catalytic activity in response to physiological conditions and specific microenvironments. Exploiting these properties in combination with the versatility of biopolymers, a fascinating field for the rational development of a new class of "smart" delivery systems for therapeutic molecules is proposed. Many strategies have been recently developed to produce matrices with the desirable properties of molecular release, and enzymes could be playing a relevant role in modify the chemical composition of the polymers, the porosity and surface area of the matrices and modulate the kinetic of controlled release. Enzyme based computational systems have appeared as a relevant complementary tool to design novel smart bioactive matrices for programmable drug delivery. The present review is reporting the recent advances and projections of smart biopolymeric matrices activated by enzymes for sustained release of therapeutic molecules, highlighting various applications in the area of advanced drug delivery.

Improving the treatment of patients with diabetes using insulin analogues: current findings and future directions

Introduction: The aim of insulin replacement in insulin-deficient people (type 1 diabetes, pancreatic causes of diabetes, long-standing type 2 diabetes) is to approximate the physiologic insulin action profile as closely as possible. However, short-acting human insulins start too slow and act too long, causing postprandial hyperglycemia and delayed hypoglycemia, while the insulin action profile of long-acting human insulins is too variable in duration and strength of action, leading to insufficient basal insulin covering and peak insulin levels after injection causing early nocturnal hypoglycemia. Insulin analogues were designed to overcome these shortcomings. In insulin-resistant people (type 2 diabetes), insulin analogues contribute to more efficient and safer insulin supplementation. Areas covered: In this review, we describe the unmet needs for insulin therapy, the currently available short- and long-acting insulin analogues and some considerations on cardiovascular outcomes, use in special populations, and cost-effectiveness. Finally, we discuss what is new in the field of insulin analogues. Expert opinion: The development of insulin analogues is an important step in diabetes treatment. Despite many patients meeting their glycemic targets with the newest analogues, hypoglycemic episodes remain a major problem. More physiologic insulin regimens, with glucose-sensitive or organ-targeting insulin analogues may be the answer to these issues.

Production of a novel heterodimeric two-chain insulin-Fc fusion protein

Insulin is a peptide hormone produced by the pancreas. The physiological role of insulin is the regulation of glucose metabolism. Under certain pathological conditions the insulin levels can be reduced leading to the metabolic disorder diabetes mellitus (DM). For type 1 DM and, dependent on the disease progression for type 2 DM, insulin substitution becomes indispensable. To relieve insulin substitution therapy for patients, novel insulin analogs with pharmacokinetic and pharmacodynamic profiles aiming for long-lasting or fast-acting insulins have been developed. The next step in the evolution of novel insulins should be insulin analogs with a time action profile beyond 1-2 days, preferable up to 1 week. Nowadays, insulin is produced in a recombinant manner. This approach facilitates the design and production of further insulin-analogs or insulin-fusion proteins. The usage of the Fc-domain from immunoglobulin as a fusion partner for therapeutic proteins and peptides is widely used to extend their plasma half-life. Insulin consists of two chains, the A- and B-chain, which are connected by two disulfide-bridges. To produce a novel kind of Fc-fusion protein we have fused the A-chain as well as the B-chain to Fc-fragments containing either 'knob' or 'hole' mutations. The 'knob-into-hole' technique is frequently used to force heterodimerization of the Fc-domain. Using this approach, we were able to produce different variants of two-chain-insulin-Fc-protein (tcI-Fc-protein) variants. The tcI-Fc-fusion variants retained activity as shown in in vitro assays. Finally, prolonged blood glucose lowering activity was demonstrated in normoglycemic rats. Overall, we describe here the production of novel insulin-Fc-fusion proteins with prolonged times of action.

Molecular engineering of safe and efficacious oral basal insulin

Recently, the clinical proof of concept for the first ultra-long oral insulin was reported, showing efficacy and safety similar to subcutaneously administered insulin glargine. Here, we report the molecular engineering as well as biological and pharmacological properties of these insulin analogues. Molecules were designed to have ultra-long pharmacokinetic profile to minimize variability in plasma exposure. Elimination plasma half-life of ~20 h in dogs and ~70 h in man is achieved by a strong albumin binding, and by lowering the insulin receptor affinity 500-fold to slow down receptor mediated clearance. These insulin analogues still stimulate efficient glucose disposal in rats, pigs and dogs during constant intravenous infusion and euglycemic clamp conditions. The albumin binding facilitates initial high plasma exposure with a concomitant delay in distribution to peripheral tissues. This slow appearance in the periphery mediates an early transient hepato-centric insulin action and blunts hypoglycaemia in dogs in response to overdosing.

Achieving Glycaemic Control with Concentrated Insulin in Patients with Type 2 Diabetes

The recent introduction of the second-generation long-acting analogue insulins degludec and insulin glargine U300 have increased the choice of basal insulin therapy for patients with type 2 diabetes. The pharmacokinetic and pharmacodynamic properties of these insulins result in a flatter profile that lasts over 24 h and provides an increased window of administration of 6 h once daily. Large-scale multicentre randomised clinical trial programmes (BEGIN for degludec U100 and U200 and EDITION for glargine U300) evaluating these insulin therapies against glargine U100 have demonstrated that they are either non-inferior or superior for glycaemic efficacy and safety, but less likely to result in severe or nocturnal hypoglycaemia than glargine U100. The disposable pen devices for these insulins have been designed with patient satisfaction and convenience in mind. No concerns have arisen with adverse events with insulin analogues or cardiovascular safety from the ORIGIN and DEVOTE trials. As they demonstrate equivalent glycaemic efficacy to other basal insulins, they should be considered more in selected patient groups including those with recurrent or increased risk of hypoglycaemia, especially severe or nocturnal episodes, in the elderly or those living alone, and in patients with multiple co-morbidities such as cardiovascular or renal disease.

Molecular and Materials Engineering for Delivery of Peptide Drugs to Treat Type 2 Diabetes

Type 2 diabetes is exploding globally. Despite numerous treatment options, nearly half of type 2 diabetics are unsuccessful at properly managing the disease, primarily due to a lack of patient compliance, driven by adverse side effects as well as complicated and frequent dosing schedules. Improving the delivery of type 2 diabetes drugs has the potential to increase patient compliance and thus, greatly enhance health outcomes and quality of life. This review focuses on molecular and materials engineering strategies that have been implemented to improve the delivery of peptide drugs to treat type 2 diabetes. Peptide drugs benefit from high potency and specificity but suffer from instability and short half-lives that limit their utility as therapeutics and pose a significant delivery challenge. Several approaches have been developed to improve the availability and efficacy of antidiabetic peptides and proteins in vivo. These methods are reviewed herein and include devices, which sustain the release of peptides in long term, and molecular engineering strategies, which prolong circulation time and slow the release of therapeutic peptides. By optimizing the delivery of these peptides and proteins using these approaches, long-term glucose control can be achieved in type 2 diabetes patients.

Polymer therapeutics at a crossroads? Finding the path for improved translation in the twenty-first century

Despite the relatively small early investment, first generation 'polymer therapeutics' have been remarkably successful with more than 25 products licenced for human use as polymeric drugs, sequestrants, conjugates, and as an imaging agent. Many exhibit both clinical and commercial success with new concepts already in clinical trials. Nevertheless after four decades of evolution, this field is arriving at an important crossroads. Over the last decade, the landscape has changed rapidly. There are an increasing number of failed clinical trials, the number of 'copy' and 'generic' products is growing (danger of ignoring the biological rationale for design and suppression of innovation), potential drawbacks of PEG are becoming more evident, and the 'nanomedicine' boom has brought danger of loss of scientific focus/hype. Grasping opportunities provided by advances in understanding of the patho-physiology and molecular basis of diseases, new polymer/conjugate synthetic and analytical methods, as well as the large database of clinical experience will surely ensure a successful future for innovative polymer therapeutics. Progress will, however, be in jeopardy if polymer safety is overlooked in respect of the specific route of administration/clinical use, poorly characterised materials/formulations are used to define biological or early clinical properties, and if clinical trial protocols fail to select patients most likely to benefit from these macromolecular therapeutics. Opportunities to improve clinical trial design for polymer-anticancer drug conjugates are discussed. This short personal perspective summarises some of the important challenges facing polymer therapeutics in R&D today, and future opportunities to improve successful translation.

Insulin analogues in type 1 diabetes mellitus: getting better all the time

The treatment of type 1 diabetes mellitus consists of external replacement of the functions of β cells in an attempt to achieve blood levels of glucose as close to the normal range as possible. This approach means that glucose sensing needs to be replaced and levels of insulin need to mimic physiological insulin-action profiles, including basal coverage and changes around meals. Training and educating patients are crucial for the achievement of good glycaemic control, but having insulin preparations with action profiles that provide stable basal insulin coverage and appropriate mealtime insulin peaks helps people with type 1 diabetes mellitus to live active lives without sacrificing tight glycaemic control. Insulin analogues enable patients to achieve this goal, as some have fast action profiles, and some have very slow action profiles, which gives people with type 1 diabetes mellitus the tools to achieve dynamic insulin-action profiles that enable tight glycaemic control with a risk of hypoglycaemia that is lower than that with human short-acting and long-acting insulins. This Review discusses the established and novel insulin analogues that are used to treat patients with type 1 diabetes mellitus and provides insights into the future development of insulin analogues.