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Fractional dosing can be a cost-effective vaccination strategy to accelerate individual and herd immunity in a pandemic. We assessed the immunogenicity and safety of primary intradermal (ID) vaccination, with a 1/5th dose compared with the standard intramuscular (IM) dose of mRNA-1273 in SARS-CoV-2 naïve persons. We conducted an open-label, non-inferiority, randomized controlled trial in the Netherlands between June and December 2021. One hundred and fifty healthy and SARS-CoV-2 naïve participants, aged 18-30 years, were randomized (1:1:1) to receive either two doses of 20 µg mRNA-1273 ID with a standard needle (SN) or the Bella-mu® needle (BM), or two doses of 100 µg IM, 28 days apart. The primary outcome was non-inferiority in seroconversion rates at day 43 (D43), defined as a neutralizing antibody concentration threshold of 465 IU/mL, the lowest response in the IM group. The non-inferiority margin was set at -15%. Neutralizing antibody concentrations at D43 were 1789 (95% CI: 1488-2150) in the IM and 1263 (951-1676) and 1295 (1020-1645) in the ID-SN and ID-BM groups, respectively. The absolute difference in seroconversion proportion between fractional and standard-dose groups was -13.95% (-24.31 to -3.60) for the ID-SN and -13.04% (-22.78 to -3.31) for the ID-BM group and exceeded the predefined non-inferiority margin. Although ID vaccination with 1/5th dose of mRNA-1273 did not meet the predefined non-inferior criteria, the neutralizing antibody concentrations in these groups are far above the proposed proxy for protection against severe disease (100 IU/mL), justifying this strategy in times of vaccine scarcity to accelerate mass protection against severe disease., (© 2024. The Author(s).)

Apraglutide (FE 203799) is a glucagon-like peptide-2 (GLP-2) analog under development for the treatment of intestinal failure associated with short bowel syndrome (SBS-IF) and graft-versus-host disease (GvHD). Compared with native GLP-2, apraglutide has slower absorption, reduced clearance, and higher protein binding, enabling once-weekly dosing. This study evaluated the pharmacokinetic (PK) and pharmacodynamic (PD) profile of apraglutide in healthy adults. Healthy volunteers were randomized to receive 6 weekly subcutaneous administrations of 1, 5, or 10 mg apraglutide or placebo. PK and citrulline (an enterocyte mass PD marker) samples were collected at multiple time points. Kinetic parameters of apraglutide and citrulline were calculated using noncompartmental analysis; repeated PD measures were analyzed with a mixed model of covariance. A population PK/PD model was developed that also included data from a previous phase 1 study in healthy volunteers. Twenty-four subjects were randomized; 23 received all study drug administrations. Mean estimated apraglutide clearance was 16.5-20.7 l/day, and mean volume of distribution was 55.4-105.0 liters. A dose-dependent increase in citrulline plasma concentration was observed, with 5-mg and 10-mg doses inducing higher citrulline levels than 1-mg doses and placebo. PK/PD analysis showed that weekly 5-mg apraglutide induced the maximal citrulline response. Increased plasma citrulline levels were sustained for 10-17 days after the final apraglutide administration. Apraglutide displays predictable dose-dependent PK and PD profiles, with a 5-mg dose showing significant PD effects. Results suggest that apraglutide has early and enduring effects on enterocyte mass and supports the continued development of weekly subcutaneous apraglutide for SBS-IF and GvHD patient populations. SIGNIFICANCE STATEMENT: Once-weekly subcutaneous apraglutide results in dose-dependent elevations of plasma citrulline (an enterocyte mass pharmacodynamic marker) with parameters suggesting that apraglutide has lasting effects on enterocyte mass and the potential to provide therapeutic benefits. This is the first report of a model relating glucagon-like peptide-2 (GLP-2) agonism and its effects in intestinal mucosa, affording not only the ability to predict pharmacologic effects of GLP-2 analogs but also the exploration of optimal dosing regimens for this drug class across populations with different body weights., (Copyright © 2023 by The Author(s).)

Background: Loss-of-function mutations in the GBA1 gene are one of the most common genetic risk factors for onset of Parkinson's disease and subsequent progression (GBA-PD). GBA1 encodes the lysosomal enzyme glucocerebrosidase (GCase), a promising target for a possible first disease-modifying therapy. LTI-291 is an allosteric activator of GCase, which increases the activity of normal and mutant forms of GCase., Objectives: This first-in-patient study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of 28 daily doses of LTI-291 in GBA-PD., Methods: This was a randomized, double-blind, placebo-controlled trial in 40 GBA-PD participants. Twenty-eight consecutive daily doses of 10, 30, or 60 mg of LTI-291 or placebo were administered (n = 10 per treatment allocation). Glycosphingolipid (glucosylceramide and lactosylceramide) levels were measured in peripheral blood mononuclear cells (PBMCs), plasma, and cerebrospinal fluid (CSF), and a test battery of neurocognitive tasks, the Movement Disorder Society-Unified Parkinson's Disease Rating Scale and the Mini-Mental State Exam, were performed., Results: LTI-291 was generally well tolerated, no deaths or treatment-related serious adverse events occurred, and no participants withdrew due to adverse events. C max , and AUC 0-6 of LTI-291 increased in a dose-proportional manner, with free CSF concentrations equal to the free fraction in plasma. A treatment-related transient increase in intracellular glucosylceramide (GluCer) in PBMCs was measured., Conclusion: These first-in-patient studies demonstrated that LTI-291 was well tolerated when administered orally for 28 consecutive days to patients with GBA-PD. Plasma and CSF concentrations that are considered pharmacologically active were reached (ie, sufficient to at least double GCase activity). Intracellular GluCer elevations were detected. Clinical benefit will be assessed in a larger long-term trial in GBA-PD. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., (© 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)

Aims: A mutation in the GBA1 gene is the most common genetic risk factor for developing Parkinson's disease. GBA1 encodes the lysosomal enzyme glucosylceramidase beta (glucocerebrosidase, GCase) and mutations decrease enzyme activity. LTI-291 is an allosteric modulator of GCase, enhancing its activity. These first-in-human studies evaluated the safety, tolerability, pharmacokinetics and pharmacodynamics of single and multiple ascending doses of LTI-291 in healthy volunteers., Methods: In the single ascending dose (SAD) study, 40 healthy volunteers were randomly assigned to LTI-291 (n = 8 per dose level) or placebo (n = 2 per dose level). Single doses of 3, 10, 30 and 90 mg LTI-291 were investigated. In the multiple ascending dose (MAD) study, 40 healthy middle-aged or elderly volunteers were randomly assigned to LTI-291 (n = 8 per dose level) or placebo (n = 2 per dose level). Fourteen consecutive daily doses of 3, 10, 30 and 60 mg LTI-291 or placebo were administered. In both the SAD and MAD studies, glycosphingolipid levels were measured and a test battery of neurocognitive tasks was performed., Results: LTI-291 was generally well tolerated and no deaths or treatment-related SAEs occurred and no subject withdrew from a study due to AEs. C max , AUC 0-24 and AUC 0-inf increased in a dose proportional manner. The median half-life was 28.0 hours after multiple dosing. No dose-dependent glycosphingolipid changes occurred. No neurocognitive adverse effects were detected., Conclusions: These first-in-human studies demonstrated that LTI-291 was well tolerated when given orally once daily for 14 consecutive days. This supports the continued clinical development and the exploration of LTI-291 effects in a GBA1-mutated Parkinson population., (© 2021 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Objective: To explore the mode of action (MoA) by which sugammadex interferes with coagulation., Materials and Methods: The effect of sugammadex on various steps in the coagulation cascade including thrombin generation, factor Xa activity, and factor Xa generation was explored in human plasma., Results: Sugammadex did not affect a conventional thrombin generation test (TGT), while it prolongs activated partial thromboplastin time (APTT) and prothrombin time (PT). However, a customized TGT with PT reagent revealed sugammadex effects. In addition, sugammadex prolonged a one-step prothrombinase-induced clotting time (PiCT) using human factor Xa. Furthermore, sugammadex interfered with factor Xa generation induced by an intrinsic and not by an extrinsic activator, nor by Russell's viper venom factor X (RVV-X)., Conclusion: Adapted, rather than standard, experiments show that sugammadex is likely to decrease factor Xa activity in the common pathway and activation of factor X specifically in the intrinsic pathway.

We aimed to characterise the population pharmacokinetics of cholesteryl ester transferase protein inhibitor DRL-17822 in healthy males and explore the effect of food and formulation on the oral absorption of DRL-17822 in 4 phase I studies. DRL-17822 was dosed orally (2-1000 mg) in 2 different drug formulations (nanocrystal formulation and amorphous solid dispersion formulation) after either an overnight fast, or a low-fat, continental or high-fat breakfast. A 2-compartment model with 6 transit absorption compartments best characterised the data. Additionally, a strong interaction of food and formulation on bioavailability was observed and parsimoniously characterised in the model by binning combinations of food state and formulation with similar bio-availabilities. The final model adequately characterised the pharmacokinetic data of DRL-17822 in healthy males including the complex interaction of food and drug formulation. The amorphous solid dispersion formulation has a lower food effect on bioavailability compared with the nanocrystal formulation., (© 2020 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.)

Objective: To investigate in vitro the effect of sugammadex on activated partial thromboplastin time (APTT) and prothrombin time (PT) prolongations with various anticoagulants as well as the neutralizing effect of rocuronium and vecuronium on sugammadex effects on APTT and PT., Materials and Methods: We investigated in vitro the effect of sugammadex on APTT and/or PT in plasma of patients on a vitamin K antagonist and with elevated international normalized ratios (INRs), in plasma of healthy subjects spiked with either a low or high concentration of enoxaparin, fondaparinux, rivaroxaban, and dabigatran, and in perioperatively collected patient plasma. In addition, we explored whether the effects of sugammadex persisted in the presence of rocuronium or vecuronium, or whether they were counteracted by these compounds., Results: Sugammadex concentration-dependently increased APTT and PT(INR) in all anticoagulant conditions, mainly in a proportional manner, with no differences between perioperatively collected patient and control plasma. Rocuronium and vecuronium both neutralized the effects of sugammadex on APTT and PT., Conclusion: Sugammadex has a transient effect on coagulation and is unlikely to increase bleeding risk, this possibility cannot be excluded for scenarios not clinically studied.

DRL-17822 is a novel selective cholesteryl ester transfer protein inhibitor that showed an increased exposure, including an increase of >20-fold of maximum concentration and area under the plasma concentration-time curve from time zero to the time of the last quantifiable concentration, following a high-fat breakfast using a nanocrystal formulation. To reduce this effect of food, we generated an amorphous solid dispersion formulation. In this study, we compared the food effect of both formulations of DRL-17822 in a 2-part randomized, open-label, 4-way crossover study involving healthy adult males 18-45 years of age. In both parts of the study, 12 subjects received both formulations of DRL-17822 in both the fasted and fed states; a low-fat breakfast was provided in the first part and a high-fat breakfast in the second part. Compared to the nanocrystal formulation, the amorphous solid dispersion formulation substantially increased DRL-17822 exposure in the fasted state, including increased maximum concentration, area under the plasma concentration-time curve from time zero to the time of the last quantifiable concentration, and area under plasma concentration-time curve from time zero to infinity. Following a high-fat breakfast, DRL-17822 exposure was increased to a lesser extent in the amorphous solid dispersion formulation compared to the nanocrystal formulation (P < .001). Moreover, compared to the nanocrystal formulation the amorphous solid dispersion formulation caused a more pronounced increase in high-density lipoprotein in the fasted state. Consuming breakfast increased the effect of DRL-17822 on high-density lipoprotein. Taken together, our results indicate that by improving its formulation, DRL-17822 has a favorable exposure profile and therefore a more predictable food effect profile., (© 2019, The American College of Clinical Pharmacology.)

This double-blind, randomized, three-way crossover study explored the potential pharmacokinetic and pharmacodynamic interactions between ethanol and brivaracetam in 18 healthy males, as required for the development of CNS-active drugs. Subjects received (A) ethanol+brivaracetam, (B) ethanol placebo+brivaracetam and (C) ethanol+brivaracetam placebo. Ethanol was infused as a 5.5-hour intravenous clamp with the first 0.5-hour as loading phase to a target level of 0.6 g/L, and brivaracetam was orally administered as a single 200 mg dose. No relevant pharmacokinetic interactions were observed. Co-administration of brivaracetam and ethanol resulted in decreased saccadic peak velocity, smooth pursuit, adaptive tracking and VAS alertness, and increased body sway, saccadic reaction time and VAS score for ethanol effect compared with brivaracetam alone or ethanol alone. Additionally, the immediate word recall scores were generally lower when brivaracetam was co-administered with ethanol, whereas the delayed word test did not show clear additional effects. A post-hoc exploratory analysis for supra-additivity suggested that most pharmacodynamic effects were likely to be additive in nature, except for adaptive tracking, which appeared to be slightly supra-additive. In conclusion, brivaracetam increased ethanol effects on psychomotor function, attention and memory in healthy males. Intake of brivaracetam with alcohol is not recommended.

Exposure-response analyses of sugammadex on activated partial thromboplastin time (APTT) and prothrombin time international normalized ratio (PT(INR)) were performed using data from two clinical trials in which subjects were co-treated with anti-coagulants, providing a framework to predict these responses in surgical patients on thromboprophylactic doses of low molecular weight or unfractionated heparin. Sugammadex-mediated increases in APTT and PT(INR) were described with a direct effect model, and this relationship was similar in the presence or absence of anti-coagulant therapy in either healthy volunteers or surgical patients. In surgical patients on thromboprophylactic therapy, model-based predictions showed 13.1% and 22.3% increases in respectively APTT and PT(INR) within 30min after administration of 16mg/kg sugammadex. These increases remain below thresholds seen following treatment with standard anti-coagulant therapy and were predicted to be short-lived paralleling the rapid decline in sugammadex plasma concentrations., (Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.)