The development and optimisation of an HPLC-based in vitro serum stability assay for a calcitonin gene-related peptide receptor antagonist peptide.

Evaluation of the stability of peptide drug candidates in biological fluids, such as blood serum, is of high importance during the lead optimisation phase. Here, we describe the optimisation and validation of a method for the evaluation of the stability of a lead calcitonin gene-related peptide antagonist peptide (P006) in blood serum. After initially determining appropriate peptide and human serum concentrations and selection of the quenching reagent, the HPLC method optimisation used two experimental designs, Plackett-Burman design and Taguchi design. The analytical method was validated as complying with the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use guidelines. The optimised method allowed the successful resolution of the parent peptide from its metabolites using RP-HPLC and identification of the major metabolites of P006 by mass spectrometry. This paradigm may be widely adopted as a robust early-stage platform for screening peptide stability to rule out candidates with low in vitro stability, which would likely translate into poor in vivo pharmacokinetics.

Dasiglucagon for the Treatment of Congenital Hyperinsulinism: A Randomized Phase 3 Trial in Infants and Children.

CONTEXT: Congenital hyperinsulinism (CHI) is characterized by dysregulated insulin secretion causing hypoglycemia and consequent brain damage. Dasiglucagon is a glucagon analogue under investigation to treat CHI. OBJECTIVE: To evaluate the efficacy and safety of dasiglucagon delivered via continuous subcutaneous infusion to children with CHI and persistent hypoglycemia as add-on to standard of care (SoC). METHODS: In this open-label trial, patients were randomized 1:1 to SoC or SoC + dasiglucagon (10-70 µg/h) for 4 weeks. In the following 4 weeks, all patients received dasiglucagon + SoC. Hypoglycemia was assessed by self-monitored plasma glucose (SMPG) and blinded continuous glucose monitoring (CGM). Primary endpoint was average number of SMPG-detected hypoglycemia episodes/week (SMPG <3.9 mmol/L) during Weeks 2 to 4. RESULTS: Thirty-two patients (0.6-10.9 years) were randomly assigned to dasiglucagon + SoC (n = 16) or SoC (n = 16). The rate of SMPG-detected hypoglycemia decreased from baseline in both groups, but with no statistically significant difference during Weeks 2 to 4 (event rate ratio: 0.85 [0.54; 1.36], P = .5028). However, dasiglucagon administration resulted in a 43% reduction in CGM-detected hypoglycemia (<3.9 mmol/L) vs SoC alone during Weeks 2 to 4 (post hoc analysis; event rate ratio: 0.57 [0.39; 0.83], P = .0029). Dasiglucagon enabled reductions (of 37% to 61%) in all other measures of hypoglycemia assessed by CGM vs SoC alone including extent and percent time in hypoglycemia (post hoc analyses). Dasiglucagon appeared safe and well tolerated. Skin and gastrointestinal events were more frequent with dasiglucagon + SoC than SoC only. CONCLUSION: Clinically meaningful reductions in all CGM-recorded measures of hypoglycemia support using dasiglucagon as a potential treatment for CHI.

Novel peptide calcitonin gene-related peptide antagonists for migraine therapy.

OBJECTIVES: It has previously been shown that the peptide (34Pro,35Phe)CGRP27-37 is a potent calcitonin gene-related peptide, CGRP receptor antagonist, and in this project we aimed to improve the antagonist potency through the structural modification of truncated C-terminal CGRP peptides. METHODS: Six peptide analogues were synthesized and the anti-CGRP activity confirmed using both in vitro and in vivo studies. KEY FINDINGS: A 10 amino acid-containing peptide VPTDVGPFAF-NH2 (P006) was identified as a key candidate to take forward for in vivo evaluation, where it was shown to be an effective antagonist after intraperitoneal injection into mice. P006 was formulated as a preparation suitable for nasal administration by spray drying with chitosan to form mucoadhesive microcarriers (9.55 ± 0.91 mm diameter) and a loading of 0.2 mg peptide per 20 mg dose. CONCLUSIONS: The project has demonstrated the potential of these novel small peptide CGRP antagonists, to undergo future preclinical evaluation as anti-migraine therapeutics.

Development of a novel cell-based, In-Cell Western/ERK assay system for the high-throughput screening of agonists acting on the delta-opioid receptor.

Background: Extracellular signal-regulated kinases (ERKs) are important signaling mediators in mammalian cells and, as a result, one of the major areas of research focus. The detection and quantification of ERK phosphorylation as an index of activation is normally conducted using immunoblotting, which does not allow high-throughput drug screening. Plate-based immunocytochemical assays provide a cheaper and relatively high-throughput alternative method for quantifying ERK phosphorylation. Here, we present optimization steps aimed to increase assay sensitivity and reduce variance and cost using the LI-COR In-Cell Western (I-CW) system in a recombinant CHO-K1 cell line, over-expressing the human delta-opioid receptor (hDOPr) as a model. Methods: Cells cultured in 96-well microassay plates were stimulated with three standard/selective DOPr agonists (SNC80, ADL5859, and DADLE) and a novel selective DOPr agonist (PN6047) to elicit a phospho-ERK response as an index of activation. A number of experimental conditions were investigated during the assay development. Key results: Preliminary experiments revealed a clearly visible edge-effect which significantly increased assay variance across the plate and which was reduced by pre-incubation for 30 min at room temperature. ERK phosphorylation was detectable as early as 1 min after agonist addition, with a distinct peak at 3-5 min. Optimization of the cell seeding densities showed that 25,000 cells per well have the lowest basal phospho-ERK response and an optimal agonist ERK1/2 signal. Pre-incubation with apyrase (an ATPase) did not reduce the basal or agonist responses. All agonists produced concentration-dependent increases in phospho-ERK activation, and pertussis toxin was able to attenuate these ERK responses. Naltrindole, which is a selective DOPr antagonist, was able to antagonize the DOPr-mediated ERK activation of the ligands. Conclusion: We have developed an optimization protocol and highlighted a number of considerations when performing this high-throughput fluorescence immunocytochemical (ICC) assay measuring ERK phosphorylation in the human DOPr. The optimized protocol was found to be a more conducive option for the screening of delta agonists. This provides a basis for additional assay development to investigate opioid pharmacology. This protocol should be widely applicable for measuring ERK phosphorylation in any cell line and investigating other protein targets in GPCR drug discovery.

Planning experiments: Updated guidance on experimental design and analysis and their reporting III.

Scientists who plan to publish in British Journal of Pharmacology (BJP) must read this article before undertaking a study. This editorial provides guidance for the design of experiments. We have published previously two guidance documents on experimental design and analysis (Curtis et al., 2015; Curtis et al., 2018). This update clarifies and simplifies the requirements on design and analysis for BJP manuscripts. This editorial also details updated requirements following an audit and discussion on best practice by the BJP editorial board. Explanations for the requirements are provided in the previous articles. Here, we address new issues that have arisen in the course of handling manuscripts and emphasise three aspects of design that continue to present the greatest challenge to authors: randomisation, blinded analysis and balance of group sizes.

Dasiglucagon demonstrates reduced costs in the treatment of severe hypoglycemia in a budget impact model.

BACKGROUND: Approximately 7.3 million people with type 1 or type 2 diabetes (T1D/T2D) are treated with insulin, placing them at higher risk of severe hypoglycemia (SH). SH requires assistance of another individual and often necessitates the prompt administration of intravenous glucose, injectable glucagon, or both. Untreated, SH can progress to unconsciousness, seizures, coma, or death. Before 2018, all glucagon rescue treatments required reconstitution. The complexity of reconstitution is often a barrier to successful administration during a severe hypoglycemic event. Studies suggest successful administration of glucagon emergency kits range from 6%-56% of the time. Second-generation glucagon treatments and glucagon analogs do not require reconstitution and have caregiver administration success rates ranging from 94%-100%. Dasiglucagon is a glucagon analog administered via autoinjector or prefilled syringe and has been shown to result in rapid hypoglycemia recovery. Moreover, the autoinjector can be administered successfully 94% of the time by trained caregivers. Previous evaluation of costs in budget impact models (BIMs) demonstrated the potential for second-generation glucagon treatments to reduce the cost of SH events (SHEs). The current model expands on those findings with a treatment pathway and accompanying assumptions reflecting important aspects of real-world SHE treatment. OBJECTIVE: To evaluate the economic impact of dasiglucagon compared with available glucagon treatments for SHE management, considering direct cost of treatment and health care resource utilization. METHODS: A 1-year BIM with a hypothetical US commercial health plan of 1 million lives was developed with a target population of individuals with diabetes at risk of SHE. The treatment pathway model included initial and secondary treatment attempts, treatment administration success and failure, plasma glucose (PG) recovery within 15 minutes, emergency medical services, emergency department (ED) visits, and hospitalizations. A 1-way sensitivity analysis was conducted to assess the sensitivity of the model to changes in parameter values. RESULTS: In a 1 million-covered lives population, it was estimated that 12,006 SHEs would occur annually. The higher rate of initial treatment success and PG recovery within 15 minutes associated with dasiglucagon treatment resulted in lower total health care costs. Total SHE treatment costs with dasiglucagon were estimated at $13.4 million, compared with $16.7 million for injectable native glucagon, $20.7 million for nasal glucagon, $35.3 million for reconstituted glucagon, and $43.8 million for untreated individuals. Compared with untreated people, the number needed to treat (NNT) with dasiglucagon was 6 individuals to avoid 1 hospitalization. NNT for this same comparison was 59 for injectable native glucagon and 27 for nasal glucagon. CONCLUSIONS: Treatment of SH with dasiglucagon decreased total direct medical costs by reducing health care resource utilization (emergency calls, emergency transports, ED visits, and hospitalizations) and accompanying costs associated with the treatment of SH. DISCLOSURES: This research was funded by Zealand Pharma. Bromley, Hinahara, and Goss are employed by Boston Healthcare Associates, Inc., which received funding from Zealand Pharma for development of the health economic model and the manuscript. Kendall and Hammer are employed by Zealand Pharma. Weinzimer has received consulting fees from Zealand Pharma.

Congenital hyperinsulinism in infancy and childhood: challenges, unmet needs and the perspective of patients and families.

BACKGROUND: Congenital hyperinsulinism (CHI) is the most common cause of persistent hypoglycemia in infants and children, and carries a considerable risk of neurological damage and developmental delays if diagnosis and treatment are delayed. Despite rapid advances in diagnosis and management, long-term developmental outcomes have not significantly improved in the past years. CHI remains a disease that is associated with significant morbidity, and psychosocial and financial burden for affected families, especially concerning the need for constant blood glucose monitoring throughout patients' lives. RESULTS: In this review, we discuss the key clinical challenges and unmet needs, and present insights on patients' and families' perspective on their daily life with CHI. Prevention of neurocognitive impairment and successful management of patients with CHI largely depend on early diagnosis and effective treatment by a multidisciplinary team of specialists with experience in the disease. CONCLUSIONS: To ensure the best outcomes for patients and their families, improvements in effective screening and treatment, and accelerated referral to specialized centers need to be implemented. There is a need to develop a wider range of centers of excellence and networks of specialized care to optimize the best outcomes both for patients and for clinicians. Awareness of the presentation and the risks of CHI has to be raised across all professions involved in the care of newborns and infants. For many patients, the limited treatment options currently available are insufficient to manage the disease effectively, and they are associated with a range of adverse events. New therapies would benefit all patients, even those that are relatively stable on current treatments, by reducing the need for constant blood glucose monitoring and facilitating a personalized approach to treatment.

Congenital hyperinsulinism (CHI) is a rare disease that causes newborn babies and children to have low blood sugar because of the abnormal release of insulin. Insulin is a hormone produced by the pancreas that promotes the transfer of sugar from the blood into the body's cells. In a healthy person, insulin is released only after a meal when the level of blood sugar is high, but infants and children with CHI make insulin even if the blood sugar is low. This can lead to dangerously low blood sugar levels, which can cause brain damage if left untreated. Unfortunately, diagnosis and treatment are often delayed, resulting in avoidable brain damage and developmental delays in these children. CHI is associated with substantial stress and anxiety for the families, especially due to the need for frequent feeding and the fear of low blood sugars added to the constant need to measure blood sugar levels. This article discusses the most important challenges and unmet needs in this rare disease, including the limited treatment options, the side effects of available treatment options and the heavy psychological, social and financial burden on affected families. Effective screening of newborns for CHI needs to be improved, and quick referral to specialized treatment centers is necessary to ensure the best outcomes for patients and families. In addition, awareness of CHI has to be raised in all medical professions caring for newborns and infants, and new medications are urgently needed to ensure the best possible treatment for all patients with CHI.

A Comparative Study of Dasiglucagon Ready-to-Use Autoinjector and Glucagon Emergency Kit During Rescue from Simulated Severe Hypoglycemia.

Background: Severe hypoglycemic episodes are life-threatening events demanding rapid administration of glucagon by a caregiver or bystander. The glucagon analog dasiglucagon is stable in aqueous formulation and therefore suitable for delivery in a ready-to-use autoinjector, potentially increasing speed and ease of use compared with standard glucagon emergency kits (GEKs). Methods: In an open label, randomized, crossover, comparative device handling study, trained caregivers and untrained bystanders administered the dasiglucagon autoinjector or Eli Lilly GEK to manikins in a simulated emergency hypoglycemia situation. Results: In total, 54 participants were randomized (18 patient-caregiver pairs and 18 bystanders). Overall, 94% of trained caregivers were able to administer the dasiglucagon autoinjector successfully within 15 min, compared with 56% for the GEK (P < 0.05). A greater proportion of trained caregivers and untrained bystanders successfully prepared and administered the dasiglucagon autoinjector within 2 min compared with the GEK (P < 0.005 and P < 0.05, respectively). Time to successful completion was also significantly faster with the dasiglucagon autoinjector than with the GEK (P < 0.005 for both groups). Most study participants preferred the dasiglucagon autoinjector over the GEK (94%, P < 0.001) and rated it as easier (90%, P < 0.001) and less stressful to use (94%, P < 0.001) than the GEK. Conclusion: Dasiglucagon autoinjector was more rapidly and reliably administered, and users reported greater ease of use and usage satisfaction than with the GEK. Thus, dasiglucagon autoinjector has the potential to improve speed and ease of treatment in severe hypoglycemic events, providing a better usage experience for rescuing individuals and enabling faster recovery for patients.

A pilot of the feasibility and usefulness of an aged obese model for use in stroke research.

Background: Animal models of stroke have been criticised as having poor predictive validity, lacking risk factors prevalent in an aging population. This pilot study examined the development of comorbidities in a combined aged and high-fat diet model, and then examined the feasibility of modelling stroke in such rats. Methods: Twelve-month old male Wistar-Han rats (n=15) were fed a 60% fat diet for 8 months during which monthly serial blood samples were taken to assess the development of metabolic syndrome and pro-inflammatory markers. Following this, to pilot the suitability of these rats for undergoing surgical models of stroke, they underwent 30min of middle cerebral artery occlusion (MCAO) alongside younger controls fed a standard diet (n=10). Survival, weight and functional outcome were monitored, and blood vessels and tissues collected for analysis. Results: A high fat diet in aged rats led to substantial obesity. These rats did not develop type 2 diabetes or hypertension. There was thickening of the thoracic arterial wall and vacuole formation in the liver; but of the cytokines examined changes were not seen. MCAO surgery and behavioural assessment was possible in this model (with some caveats discussed in manuscript). Conclusions: This study shows MCAO is possible in aged, obese rats. However, this model is not ideal for recapitulating the complex comorbidities commonly seen in stroke patients.

RESULTS OF A 24-WEEK TRIAL OF TECHNOSPHERE INSULIN VERSUS INSULIN ASPART IN TYPE 2 DIABETES.

OBJECTIVE: To compare glycemic efficacy of Technosphere insulin (TI) versus that of insulin aspart (IA), each added to basal insulin, in type 2 diabetes. METHODS: This randomized, 24-week trial included subjects aged from 18 to 80 years who were treated with subcutaneous insulin for 3 months and had glycated hemoglobin (HbA1C) levels of 7.0% to 11.5%. After receiving stabilized insulin glargine doses during a 4-week lead in, the subjects were randomized to TI or IA. The primary end point was an HbA1C change from baseline, with the differences analyzed by equivalence analyses. RESULTS: In the overall cohort (N = 309; males, 23.3%), mean (SD) age was 58.5 (8.4) years, body mass index was 30.8 (4.7) kg/m2, weight was 82.2 (13.6) kg, and duration of diabetes was 12.2 (7.1) years. An intention-to-treat cohort had 150 subjects randomized to TI (mean [SD] HbA1C: 8.9% [1.1%]) and 154 randomized to IA (mean [SD] HbA1C: 9.0% [1.3%]). At 24 weeks, mean (SD) HbA1C value declined to 7.9% (1.3%) and 7.7% (1.1%) in the TI and IA cohorts, respectively. A treatment difference of 0.26% was not statistically significant, but the predefined equivalency margin was not met. Subjects receiving TI lost 0.78 kg compared to baseline; subjects receiving IA gained 0.23 kg (P =.0007). The incidence of mild/moderate hypoglycemia was lower for the TI cohort, though not statistically significant. CONCLUSION: Both TI and IA resulted in significant and clinically meaningful HbA1C reductions. TI also resulted in significant and clinically meaningful weight reductions. These data support the use of inhaled insulin as a treatment option for individuals with type 2 diabetes.

Understanding inhaled Technosphere Insulin: Results of an early randomized trial in type 1 diabetes mellitus.

BACKGROUND: Technosphere Insulin (TI) is an inhaled insulin. Studies comparing TI with short-acting insulin analogues provide important insights on efficacy, dosing, and time course of action. METHODS: Planned enrollment of 230 subjects was limited to 138 due to premature study discontinuation. The primary efficacy endpoint was a noninferiority of glycosylated hemoglobin (HbA1c) of 0.4% for TI compared with insulin lispro (LIS) in a 16-week phase 3 randomized clinical trial in type 1 diabetes mellitus. RESULTS: HbA1c values were similar in the TI and LIS groups at the beginning of the trial (7.8% and 7.6%, respectively) and at trial endpoint (7.7% and 7.6%, respectively). Least squares mean changes from baseline were similar between study groups. Glucose values after a standard meal were significantly lower with TI in the first 90 minutes post meal compared with LIS. Mild or moderate hypoglycemia event rates were also significantly lower with TI compared with LIS (5.97 vs 8.01, respectively; P = .0269). Cough was the most commonly reported adverse event with TI. Pulmonary function as measured by forced expiratory volume in 1 second was not different between groups at baseline, 16 weeks, or 4 weeks off study drug. CONCLUSIONS: HbA1c was unchanged and overall glucose control was comparable between groups. Treatment with TI resulted in improved post-meal glucose and a lower risk of hypoglycemia compared with LIS.

Comprehensive Pulmonary Safety Review of Inhaled Technosphere® Insulin in Patients with Diabetes Mellitus.

BACKGROUND AND OBJECTIVE: Technosphere® Insulin (TI), a human insulin powder for inhalation (Afrezza®; MannKind Corporation, Westlake Village, CA, USA), is an ultra-rapid-acting inhaled insulin indicated to improve postprandial glycemic control in patients with type 1 or type 2 diabetes mellitus (T1DM or T2DM). Because TI is absorbed across the alveolar membrane, the objective of this analysis was to characterize its pulmonary safety. METHODS: Pooled data from 13 phase 2/3 clinical studies in 5505 patients with T1DM or T2DM treated with TI, Technosphere inhalation powder without insulin (TP; placebo), or active-comparator treatment were analyzed for incidences of respiratory treatment-emergent adverse events (TEAEs), changes in pulmonary function, and lung malignancies. Radiographic changes in the lungs were monitored in a subset of 229 patients. RESULTS: Among 3017 patients receiving TI, the median duration of TI exposure was 168 days; median active-comparator and TP exposure durations were 363 and 149 days for 2198 and 290 patients, respectively. Respiratory TEAEs were comparable across treatments, except for a higher incidence of mild cough with TI in active-comparator studies (28.0% vs. 5.2%). Slight reversible declines in pulmonary function from baseline were observed for TI versus TP and active-comparator treatments, including in a subpopulation of patients with retrospectively identified lung dysfunction. Lung malignancies were reported in two patients on active TI therapy with a smoking history. No clinically significant changes from baseline were observed in radiographic images. CONCLUSIONS: Pulmonary safety assessment of the TI inhalation system did not identify any safety issues in individuals with either T1DM or T2DM.

A CGRP receptor antagonist peptide formulated for nasal administration to treat migraine.

OBJECTIVES: To investigate the formulation of the peptide-based antagonist (34 Pro,35 Phe)CGRP27-37 , of the human calcitonin gene-related peptide (CGRP) receptor as a potential nasally delivered migraine treatment. METHODS: Peptide sequences were prepared using automated methods and purified by preparative HPLC. Their structure and stability were determined by LC-MS. Antagonist potency was assessed by measuring CGRP-stimulated cAMP accumulation in SK-N-MC, cells and in CHO cells overexpressing the human CGRP receptor. In vivo activity was tested in plasma protein extravasation (PPE) studies using Evans blue dye accumulation. Peptide-containing chitosan microparticles were prepared by spray drying. KEY FINDINGS: (34 Pro,35 Phe)CGRP27-37 exhibited a 10-fold increased affinity compared to αCGRP27-37 . Administration of (34 Pro,35 Phe)CGRP27-37 to mice led to a significant decrease in CGRP-induced PPE confirming antagonistic properties in vivo. There was no degradation of (34 Pro,35 Phe)CGRP27-37 and no loss of antagonist potency during formulation and release from chitosan microparticles. CONCLUSIONS: (34 Pro,35 Phe)CGRP27-37 is a potent CGRP receptor antagonist both in vitro and in vivo, and it can be formulated as a dry powder with no loss of activity indicating its potential as a nasally formulated anti-migraine medicine.

Sex-specific hippocampal metabolic signatures at the onset of systemic inflammation with lipopolysaccharide in the APPswe/PS1dE9 mouse model of Alzheimer's disease.

Systemic inflammation enhances the risk and progression of Alzheimer's disease (AD). Lipopolysaccharide (LPS), a potent pro-inflammatory endotoxin produced by the gut, is found in excess levels in AD where it associates with neurological hallmarks of pathology. Sex differences in susceptibility to inflammation and AD progression have been reported, but how this impacts on LPS responses remains under investigated. We previously reported in an APP/PS1 model of AD that systemic LPS administration rapidly altered hippocampal metabolism in males. Here, we used untargeted metabolomics to comprehensively identify hippocampal metabolic processes occurring at onset of systemic inflammation with LPS (100 µg/kg, i.v.) in APP/PS1 mice, at an early pathological stage, and investigated the sexual dimorphism in this response. Four hours after LPS administration, pathways regulating energy metabolism, immune and oxidative stress responses were simultaneously recruited in the hippocampi of 4.5-month-old mice with a more protective response in females despite their pro-inflammatory and pro-oxidant metabolic signature in the absence of immune stimulation. LPS induced comparable behavioural sickness responses in male and female wild-type and APP/PS1 mice and comparable activation of both the serotonin and nicotinamide pathways of tryptophan metabolism in their hippocampi. Elevations in N-methyl-2-pyridone-5-carboxamide, a major toxic metabolite of nicotinamide, correlated with behavioural sickness regardless of sex, as well as with the LPS-induced hypothermia seen in males. Males also exhibited a pro-inflammatory-like downregulation of pyruvate metabolism, exacerbated in APP/PS1 males, and methionine metabolism whereas females showed a greater cytokine response and anti-inflammatory-like downregulation of hippocampal methylglyoxal and methionine metabolism. Metabolic changes were not associated with morphological markers of immune cell activation suggesting that they constitute an early event in the development of LPS-induced neuroinflammation and AD exacerbation. These data suggest that the female hippocampus is more tolerant to acute systemic inflammation.

A Novel G Protein-Biased Agonist at the δ Opioid Receptor with Analgesic Efficacy in Models of Chronic Pain.

Agonists at the δ opioid receptor are known to be potent antihyperalgesics in chronic pain models and effective in models of anxiety and depression. However, some δ opioid agonists have proconvulsant properties while tolerance to the therapeutic effects can develop. Previous evidence indicates that different agonists acting at the δ opioid receptor differentially engage signaling and regulatory pathways with significant effects on behavioral outcomes. As such, interest is now growing in the development of biased agonists as a potential means to target specific signaling pathways and potentially improve the therapeutic profile of δ opioid agonists. Here, we report on PN6047 (3-[[4-(dimethylcarbamoyl)phenyl]-[1-(thiazol-5-ylmethyl)-4-piperidylidene]methyl]benzamide), a novel G protein-biased and selective δ opioid agonist. In cell-based assays, PN6047 fully engages G protein signaling but is a partial agonist in both the arrestin recruitment and internalization assays. PN6047 is effective in rodent models of chronic pain but shows no detectable analgesic tolerance following prolonged treatment. In addition, PN6047 exhibited antidepressant-like activity in the forced swim test, and importantly, the drug had no effect on chemically induced seizures. PN6047 did not exhibit reward-like properties in the conditioned place preference test or induce respiratory depression. Thus, δ opioid ligands with limited arrestin signaling such as PN6047 may be therapeutically beneficial in the treatment of chronic pain states. SIGNIFICANCE STATEMENT: PN6047 (3-[[4-(dimethylcarbamoyl)phenyl]-[1-(thiazol-5-ylmethyl)-4-piperidylidene]methyl]benzamide) is a selective, G protein-biased δ opioid agonist with efficacy in preclinical models of chronic pain. No analgesic tolerance was observed after prolonged treatment, and PN6047 does not display proconvulsant activity or other opioid-mediated adverse effects. Our data suggest that δ opioid ligands with limited arrestin signaling will be beneficial in the treatment of chronic pain.

A multinational observational study assessing insulin use: Understanding the determinants associated with progression of therapy.

AIMS: To describe global patterns of insulin treatment and to assess the impact of patient, provider, health system and economic influences on treatment decisions for patients with insulin-treated type 2 diabetes (T2D). METHODS: This prospective cohort study of insulin-treated patients with T2D was conducted across 18 countries categorized as high, upper-middle or lower-middle income regions. Information collected from patients included knowledge of diabetes, experiences and interactions with their healthcare provider. Physician information included specialty, practice size, availability of diabetes support services, volume of diabetes patients treated and time spent per patient. Physicians determined an individualized haemoglobin A1c (HbA1c) target for each patient by the start of the study. Changes in T2D therapies and HbA1c were recorded for 2 years. RESULTS: Complete treatment data were available for 2528 patients. Median age was 61 years and median duration of diabetes was 11.4 years. Changes to treatment regimen occurred in 90.0% of patients, but changes were less common in countries with a higher economic status (P < 0.001). Most treatment changes involved insulin, with changes in dose the most common. Overall predictors of change in insulin therapy included younger age, use of any insulin regimen other than basal only, higher mean baseline HbA1c and longer duration of T2D. HbA1c levels remained constant regardless of regional economic status. At baseline, 20.6% of patients were at their HbA1c target; at 2 years this was 26.8%. CONCLUSIONS: Among insulin-treated patients with T2D, treatment changes were common; however, only approximately one-fourth of individuals achieved their HbA1c target.