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Retinoic acid receptor β2 (RARβ2) is an emerging therapeutic target for spinal cord injuries (SCIs) with a unique multimodal regenerative effect. We have developed a first-in-class RARβ agonist drug, C286, that modulates neuron-glial pathways to induce functional recovery in a rodent model of sensory root avulsion. Here, using genome-wide and pathway enrichment analysis of avulsed rats' spinal cords, we show that C286 also influences the extracellular milieu (ECM). Protein expression studies showed that C286 upregulates tenascin-C, integrin-α9, and osteopontin in the injured cord. Similarly, C286 remodulates these ECM molecules, hampers inflammation and prevents tissue loss in a rodent model of spinal cord contusion C286. We further demonstrate C286's efficacy in human iPSC-derived neurons, with treatment resulting in a significant increase in neurite outgrowth. Additionally, we identify a putative efficacy biomarker, S100B, which plasma levels correlated with axonal regeneration in nerve-injured rats. We also found that other clinically available retinoids, that are not RARβ specific agonists, did not lead to functional recovery in avulsed rats, demonstrating the requirement for RARβ specific pathways in regeneration. In a Phase 1 trial, the single ascending dose (SAD) cohorts showed increases in expression of RARβ2 in white blood cells correlative to increased doses and at the highest dose administered, the pharmacokinetics were similar to the rat proof of concept (POC) studies. Collectively, our data suggests that C286 signalling in neurite/axonal outgrowth is conserved between species and across nerve injuries. This warrants further clinical testing of C286 to ascertain POC in a broad spectrum of neurodegenerative conditions., Competing Interests: MG and JC have a matter of composition patent for KCL-286. JT was employed by Richmond Pharmacology Limited. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Goncalves, Wu, Clarke, Grist, Moehlin, Mendoza-Parra, Hobbs, Kalindjian, Fok, Mander, Hassanin, Bendel, Täubel, Mant, Carlstedt, Jack and Corcoran.)

Aims: KCL-286 is an orally available agonist that activates the retinoic acid receptor (RAR) β2, a transcription factor which stimulates axonal outgrowth. The investigational medicinal product is being developed for treatment of spinal cord injury (SCI). This adaptive dose escalation study evaluated the tolerability, safety and pharmacokinetics and pharmacodynamic activity of KCL-286 in male healthy volunteers to establish dosing to be used in the SCI patient population., Methods: The design was a double blind, randomized, placebo-controlled dose escalation study in 2 parts: a single ascending dose adaptive design with a food interaction arm, and a multiple ascending dose design. RARβ2 mRNA expression was evaluated in white blood cells., Results: At the highest single and multiple ascending doses (100 mg), no trends or clinically important differences were noted in the incidence or intensity of adverse events (AEs), serious AEs or other safety assessments with none leading to withdrawal from the study. The AEs were dry skin, rash, skin exfoliation, raised liver enzymes and eye disorders. There was an increase in mean maximum observed concentration and area under the plasma concentration-time curve up to 24 h showing a trend to subproportionality with dose. RARβ2 was upregulated by the investigational medicinal product in white blood cells., Conclusion: KCL-286 was well tolerated by healthy human participants following doses that exceeded potentially clinically relevant plasma exposures based on preclinical in vivo models. Target engagement shows the drug candidate activates its receptor. These findings support further development of KCL-286 as a novel oral treatment for SCI., (© 2023 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Acute hyperglycemia causes various cardiovascular responses; however, the underlying pathophysiology in vivo is myriad and complex, of which mutual interactions remain poorly understood. We analyzed the cardiovascular effects of acute hyperglycemia in comparison with those of hyperosmolality alone. Three g/kg of D-glucose (n = 4) or D-mannitol (n = 4) was intravenously infused to isoflurane-anesthetized intact dogs. Glucose infusion increased plasma glucose level and osmolality, whereas mannitol infusion similarly changed osmolality to glucose infusion but decreased glucose level. Glucose infusion decreased total peripheral vascular resistance, but increased heart rate, left ventricular contraction, left ventricular preload and cardiac output without altering mean blood pressure. Mannitol infusion likewise changed them, but its positive chronotropic and inotropic effects were less potent than those of glucose infusion. Glucose infusion prolonged PR interval, QRS width and QTcV. Mannitol infusion similarly changed them, but its QTcV prolongation was smaller than that of glucose infusion. Glucose infusion-induced cardiovascular responses would be basically attributed to osmolality-dependent mechanisms, whereas its positive chronotropic and inotropic effects along with repolarization delay may be enhanced by osmolality-independent mechanisms, including hyperglycemia by itself and insulin release.

Aims: Given the increasing emergence of drug resistance in Plasmodium, new antimalarials are urgently required. P218 is an aminopyridine that inhibits dihydrofolate reductase being developed as a malaria chemoprotective drug. Assessing the effect of new compounds on cardiac intervals is key during early drug development to determine their cardiac safety., Methods: This double-blind, randomized, placebo-controlled, parallel group study evaluated the effect of P218 on electrocardiographic parameters following oral administration of seven single-ascending doses up to 1000 mg in 56 healthy volunteers. Participants were randomized to treatment or placebo at a 3:1 ratio. P218 was administered in the fasted state with standardized lunch served 4 hours after dosing. 12-lead ECGs were recorded in triplicate at regular intervals on the test day, and at 48, 72, 120, 168, 192 and 240 hours thereafter. Blood samples for pharmacokinetic evaluations were collected at similar time points. Concentration-effect modelling was used to assess the effect of P218 and its metabolites on cardiac intervals., Results: Concentration-effect analysis showed that P218 does not prolong the QTcF, J-Tpeak or TpTe interval at all doses tested. No significant changes in QRS or PR intervals were observed. Two-sided 90% confidence intervals of subinterval effects of P218 and its metabolites were consistently below the regulatory concern threshold for all doses. Study sensitivity was confirmed by significant shortening of QTcF after a meal., Conclusion: Oral administration of P218 up to 1000 mg does not prolong QTcF and does not significantly change QRS or PR intervals, suggesting low risk for drug-induced proarrhythmia., (© 2021 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

We aim to study kinetics of anti-SARS-CoV-2 IgG antibody levels in subjects with COVID-19 for up to 11 months and the potential influential factors. The study was a prospective longitudinal study. The analyses were based on 77 serum/plasma samples with a mean of 4 samples per participant (range 1 - 18) in 20 participants with at least one positive Polymerase Chain Reaction testing result from 19 March 2020 up to 10 February 2021. Among the subjects (median age 34.5 years, 65% male), IgG level declined with the follow-up time (per month; geometric mean ratio [GMR] 0.73; 95% CI, 0.72 - 0.74). In a small sample of subjects from the general population with COVID-19, IgG levels declined non-linearly from month 2 to 11 with individual heterogeneity in quantity and changing speed and may be associated with gender, race and the loss of smell and taste., Competing Interests: Declaration of competing interests The authors declare that they have no competing interests., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: A number of single-inhaler, fixed-dose, triple combinations are available for the management of chronic obstructive pulmonary disease and/or asthma. One of these is the extrafine formulation beclomethasone dipropionate, formoterol fumarate, glycopyrronium bromide (BDP/FF/GB). Given that differences in ethnicity can result in differences in systemic exposure, we evaluated the relative pharmacokinetic (PK) profiles of BDP/FF/GB in Japanese vs Caucasian healthy volunteers to assess the need for dose adjustment., Methods: This randomized, double-blind, single-dose, 4-way crossover study recruited healthy men and women 20 to 55 years of age; for each Japanese person a Caucasian was enrolled who matched in terms of sex, age, and weight. Study treatments included BDP/FF/GB 200/12/25 and 400/12/25 μg (therapeutic), 800/48/100 μg (supratherapeutic), and placebo. PK blood samples were taken up to 24 hours for evaluation of BDP, beclomethasone 17-monopropionate (B17MP, an active metabolite of BDP), and formoterol and up to 48 h for GB. The primary objective was to characterize the PK profiles of BDP, FF, and GB after administration of a single dose of BDP/FF/GB in Caucasian and Japanese healthy volunteers in terms of the AUC 0-t and C max of B17MP, formoterol, and GB., Findings: Of the 32 recruited participants (16 Japanese and 16 Caucasian ), 30 completed the study. A clear plasma exposure dose-response relationship was found for all 4 molecules. B17MP C max geometric mean ratios for Japanese vs Caucasian participants for the 3 study treatments ranged from 1.17 to 1.26, and AUC 0-t ratios ranged from 1.16 to 1.22; thus, the findings were comparable between the ethnicities. Formoterol exposure was higher in Japanese than Caucasian participants (C max , 1.22-1.53; AUC 0-t , 1.23-1.40). The GB C max with BDP/FF/GB 400/12/25 μg (1.09) and AUC 0-t values for all three doses (0.98-1.17) were comparable in the 2 populations, but C max with 200/12/25 and 800/48/100 μg were higher in Japanese participants (1.32 and 1.42, respectively). Pharmacodynamic (cortisol, potassium, glucose, blood pressure, heart rate, and QT interval with the Fridericia correction) and safety profile results were similar in the 2 ethnicities, with most patients not experiencing any adverse events., Implications: Exposure to BDP/FF/GB pressurized metered dose inhaler at therapeutic and supratherapeutic doses was associated with higher plasma levels in Japanese versus Caucasian healthy volunteers. These PK differences did not translate into meaningful differences in the safety or pharmacodynamic parameters assessed in this study and were consistent with the results of other long-term (52-week) published studies. Dose adjustments in Japanese people are not deemed necessary. CLINICALTRIALS., Gov Identifier: NCT03859414., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)