A Phase 1, Randomised, Placebo-Controlled, Dose Escalation Study to Investigate the Safety, Tolerability and Pharmacokinetics of Cannabidiol in Fed Healthy Volunteers.

BACKGROUND: There is increasing interest in the use of purified cannabidiol (CBD) as a treatment for a wide range of conditions due to its reported anti-inflammatory, anxiolytic, antiemetic and anticonvulsant properties. OBJECTIVE: The objective of this study was to assess the safety, tolerability and pharmacokinetics of a single ascending dose of a new lipid-based oral formulation of CBD in healthy volunteers after a high-fat meal. METHODS: A total of 24 eligible healthy volunteers (aged 18-48 years) were randomised to one of three sequential cohorts (each with six active and two placebo subjects). Cohort 1 received 5 mg/kg CBD or placebo, cohort 2 received 10 mg/kg CBD or placebo (cohort 2), and cohort 3 received 20 mg/kg CBD or placebo. Data relating to adverse events, vital signs, clinical laboratory assessments, 12-lead ECGs, physical examinations and concomitant medications were collected to assess safety and tolerability. Blood samples were collected up to 8 days postdose and plasma was analysed by liquid chromatography and mass spectrometry to assess the pharmacokinetics of the CBD formulation. RESULTS: CBD was well tolerated in the healthy volunteers (mean age: 24.0 years) treated with a single oral dose of CBD. There were no safety concerns with increasing the dose and the safety profiles of the CBD-treated and placebo-treated subjects were similar. The most frequently reported treatment emergent adverse events (TEAEs) were headache (17%) and diarrhoea (8%). There were no reported serious adverse events (SAEs) and no clinical laboratory findings, vital signs, ECGs or physical examination findings that were reported as TEAEs or were of clinical significance during the study. After a high-fat meal, CBD was detected in plasma samples at 15 min postdose; the median time to maximum plasma concentration (Tmax) was 4 h across all three CBD dose cohorts. The CBD plasma exposure [maximum observed plasma concentration (Cmax) and the area under the concentration-time curve (AUC)] increased in a dose-proportional manner and declined to levels approaching the lower level of quantification by day 8. The terminal elimination half-life was approximately 70 h, suggesting that 2-3 weeks are needed to fully eliminate CBD. CONCLUSIONS: This new CBD formulation demonstrated a favourable safety and tolerability profile in healthy volunteers that was consistent with the profiles reported for other purified CBD products. No severe or serious AEs were observed in this study and there were no safety concerns. TRIAL REGISTRATION: ACTRN12618001424291. Registered August 2018.

Safety, tolerability, and immunogenicity of influenza vaccination with a high-density microarray patch: Results from a randomized, controlled phase I clinical trial.

BACKGROUND: The Vaxxas high-density microarray patch (HD-MAP) consists of a high density of microprojections coated with vaccine for delivery into the skin. Microarray patches (MAPs) offer the possibility of improved vaccine thermostability as well as the potential to be safer, more acceptable, easier to use, and more cost-effective for the administration of vaccines than injection by needle and syringe (N&S). Here, we report a phase I trial using the Vaxxas HD-MAP to deliver a monovalent influenza vaccine that was to the best of our knowledge the first clinical trial to evaluate the safety, tolerability, and immunogenicity of lower doses of influenza vaccine delivered by MAPs. METHODS AND FINDINGS: HD-MAPs were coated with a monovalent, split inactivated influenza virus vaccine containing A/Singapore/GP1908/2015 H1N1 haemagglutinin (HA). Between February 2018 and March 2018, 60 healthy adults (age 18-35 years) in Melbourne, Australia were enrolled into part A of the study and vaccinated with either: HD-MAPs delivering 15 µg of A/Singapore/GP1908/2015 H1N1 HA antigen (A-Sing) to the volar forearm (FA); uncoated HD-MAPs; intramuscular (IM) injection of commercially available quadrivalent influenza vaccine (QIV) containing A/Singapore/GP1908/2015 H1N1 HA (15 µg/dose); or IM injection of H1N1 HA antigen (15 µg/dose). After 22 days' follow-up and assessment of the safety data, a further 150 healthy adults were enrolled and randomly assigned to 1 of 9 treatment groups. Participants (20 per group) were vaccinated with HD-MAPs delivering doses of 15, 10, 5, 2.5, or 0 µg of HA to the FA or 15 µg HA to the upper arm (UA), or IM injection of QIV. The primary objectives of the study were safety and tolerability. Secondary objectives were to assess the immunogenicity of the influenza vaccine delivered by HD-MAP. Primary and secondary objectives were assessed for up to 60 days post-vaccination. Clinical staff and participants were blind as to which HD-MAP treatment was administered and to administration of IM-QIV-15 or IM-A/Sing-15. All laboratory investigators were blind to treatment and participant allocation. Two further groups in part B (5 participants per group), not included in the main safety and immunological analysis, received HD-MAPs delivering 15 µg HA or uncoated HD-MAPs applied to the forearm. Biopsies were taken on days 1 and 4 for analysis of the cellular composition from the HD-MAP application sites. The vaccine coated onto HD-MAPs was antigenically stable when stored at 40°C for at least 12 months. HD-MAP vaccination was safe and well tolerated; any systemic or local adverse events (AEs) were mild or moderate. Observed systemic AEs were mostly headache or myalgia, and local AEs were application-site reactions, usually erythema. HD-MAP administration of 2.5 µg HA induced haemagglutination inhibition (HAI) and microneutralisation (MN) titres that were not significantly different to those induced by 15 µg HA injected IM (IM-QIV-15). HD-MAP delivery resulted in enhanced humoral responses compared with IM injection with higher HAI geometric mean titres (GMTs) at day 8 in the MAP-UA-15 (GMT 242.5, 95% CI 133.2-441.5), MAP-FA-15 (GMT 218.6, 95% CI 111.9-427.0), and MAP-FA-10 (GMT 437.1, 95% CI 254.3-751.3) groups compared with IM-QIV-15 (GMT 82.8, 95% CI 42.4-161.8), p = 0.02, p = 0.04, p < 0.001 for MAP-UA-15, MAP-FA-15, and MAP-FA-10, respectively. Higher titres were also observed at day 22 in the MAP-FA-10 (GMT 485.0, 95% CI 301.5-780.2, p = 0.001) and MAP-UA-15 (367.6, 95% CI 197.9-682.7, p = 0.02) groups compared with the IM-QIV-15 group (GMT 139.3, 95% CI 79.3-244.5). Results from a panel of exploratory immunoassays (antibody-dependent cellular cytotoxicity, CD4+ T-cell cytokine production, memory B cell (MBC) activation, and recognition of non-vaccine strains) indicated that, overall, Vaxxas HD-MAP delivery induced immune responses that were similar to, or higher than, those induced by IM injection of QIV. The small group sizes and use of a monovalent influenza vaccine were limitations of the study. CONCLUSIONS: Influenza vaccine coated onto the HD-MAP was stable stored at temperatures up to 40°C. Vaccination using the HD-MAP was safe and well tolerated and resulted in immune responses that were similar to or significantly enhanced compared with IM injection. Using the HD-MAP, a 2.5 µg dose (1/6 of the standard dose) induced HAI and MN titres similar to those induced by 15 µg HA injected IM. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR.org.au), trial ID 108 ACTRN12618000112268/U1111-1207-3550.

Effect of food on the pharmacokinetics of piperaquine and dihydroartemisinin.

BACKGROUND AND OBJECTIVE: Piperaquine-dihydroartemisinin combination therapy has established efficacy for the treatment of malaria; however, a more comprehensive understanding of the pharmacokinetic properties and factors contributing to inter- and intra-individual variability is critical to optimize clinical use. This study assessed the effects of food on the pharmacokinetics of combination piperaquine-dihydroartemisinin administration in healthy volunteers. METHODS: This was an open-label, single-dose, parallel-group study. Participants were randomly allocated to receive oral piperaquine-dihydroartemisinin either after an overnight fast or immediately after a standardized, high-fat, high-calorie meal. Blood samples were collected for analysis of plasma piperaquine and dihydroartemisinin concentrations, which were utilized for calculation of pharmacokinetic parameters, using a standard model-independent approach. RESULTS: Consumption of a high-fat, high-calorie meal resulted in substantial increases in the extent of exposure to piperaquine (ratio between area under the plasma concentration-time curve [AUC] values from 0 to 168 h in the fed and fasted states [AUC0-168 h FED/AUC0-168 h FASTED] = 299 %, 90 % confidence interval [CI] 239-374 %). This likely reflects an increase in the oral bioavailability of the drug, directly related to the fat content of the meal. Co-administration of food was also found to result in both delayed and enhanced absorption of dihydroartemisinin (ratio between AUC values from time zero to infinity in the fed and states [AUC∞ FED/AUC∞ FASTED] = 142 %, 90 % CI 113-178 %; ratio between mean transit time [MTT] values in the fed and fasted states [MTTFED/MTTFASTED] = 135 %, 90 % CI 114-160 %). CONCLUSION: Although food was found to significantly impact on the pharmacokinetics of piperaquine and dihydroartemisinin, given the low fat content of standard meals within endemic regions and the anorexic effects of malaria infection, these results are unlikely to impact on the clinical utility of these drugs. However, co-administration of food with these anti-malarials by populations consuming a typical Western diet should be avoided to reduce the risk of toxic side effects. It is therefore a general recommendation that piperaquine-dihydroartemisinin not be administered within ±3 h of food consumption.

The plasma-occupancy relationship of the novel GABAA receptor benzodiazepine site ligand, alpha5IA, is similar in rats and primates.

BACKGROUND AND PURPOSE: alpha5IA (3-(5-methylisoxazol-3-yl)-6-[(1-methyl-1,2,3-triazol-4-yl)methyloxy]-1,2,4-triazolo[3,4-a]phthalazine) is a triazolophthalazine with subnanomolar affinity for alpha1-, alpha2-, alpha3- and alpha5-containing GABA(A) receptors. Here we have evaluated the relationship between plasma alpha5IA concentrations and benzodiazepine binding site occupancy in rodents and primates (rhesus monkey). EXPERIMENTAL APPROACH: In awake rats, occupancy was measured at various times after oral dosing with alpha5IA (0.03-30 mgxkg(-1)) using an in vivo {[(3)H]flumazenil (8-fluoro 5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylic acid ethyl ester)} binding assay. In anaesthetized rhesus monkeys, occupancy was measured using {[(123)I]iomazenil (ethyl 5,6-dihydro-7-iodo-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylic acid ethyl ester)} gamma-scintigraphy and a bolus/infusion paradigm. In both rat and rhesus monkey, the plasma drug concentration corresponding to 50% occupancy (EC(50)) was calculated. KEY RESULTS: In rats, alpha5IA occupancy was dose- and time-dependent with maximum occupancy occurring within the first 2 h. However, rat plasma EC(50) was time-independent, ranging from 42 to 67 ngxmL(-1) over a 24 h time course with the average being 52 ngxmL(-1) (i.e. occupancy decreased as plasma drug concentrations fell). In rhesus monkeys, the EC(50) for alpha5IA displacing steady-state [(123)I]iomazenil binding was 57 ngxmL(-1). CONCLUSIONS AND IMPLICATIONS: Rat plasma EC(50) values did not vary as a function of time indicating that alpha5IA dissociates readily for the GABA(A) receptor in vivo. These data also suggest that despite the different assays used (terminal assays of [(3)H]flumazenil in vivo binding in rats and [(123)I]iomazenil gamma-scintigraphy in anaesthetized rhesus monkeys), these techniques produced similar plasma alpha5IA EC(50) values (52 and 57 ngxmL(-1) respectively) and that the plasma-occupancy relationship for alpha5IA translates across these two species.

Evaluation of eight anti-rubella virus immunoglobulin g immunoassays that report results in international units per milliliter.

An evaluation of anti-rubella virus immunoglobulin G (IgG) immunoassays that report in international units per milliliter (IU/ml) was performed to determine their analytical performance and the degree of correlation of the test results. A total of 321 samples were characterized based on results from a hemagglutination inhibition assay. The 48 negative and 273 positive samples were used to determine the sensitivity and specificity of the assays. When equivocal results were interpreted as reactive, the sensitivity of the immunoassays ranged from 98.9 to 99.9% and the specificity ranged from 77.1 to 95.8%. All assays had positive and negative delta values of less than 2. A significant difference between the mean results of all assays was demonstrated by analysis of variance. However, post hoc analysis showed there was good correlation in the mean results expressed in IU/ml between some of the assays. Our results show the level of standardization between anti-rubella virus IgG immunoassays reporting results expressed as IU/ml has improved since a previous study in 1992, but further improvement is required.

Safety and efficacy of intravenous N-acetylcysteine for acetaminophen overdose: analysis of the Hunter Area Toxicology Service (HATS) database.

BACKGROUND: Acetaminophen (N-acetyl-p-aminophenyl; APAP) is the leading drug used in self-poisoning and frequently causes hepatotoxicity, including acute liver failure. OBJECTIVE: To provide descriptive data on the safety and efficacy of intravenous N-acetylcysteine (IV-NAC) in the treatment of APAP toxicity, based on information in the Hunter Area Toxicology Service (HATS) database involving residents of the Greater Newcastle Area of New South Wales, Australia. METHODS: This was a retrospective analysis of all APAP overdoses from January 1987 to January 2003. Data were collected prospectively according to a published protocol and included patient characteristics, exposures to APAP and other potential toxins, treatments, and outcomes. Primary safety/tolerability endpoints included the mortality rate and incidence of adverse drug reactions, while efficacy endpoints included alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. RESULTS: Of 1749 patients, 399 (22.8%) were treated with IV-NAC. Of these, 37 (9.3%) had an adverse drug reaction to IV-NAC, of which seven (1.8% of total) were anaphylactoid. There were five deaths in hospital (mortality rate = 0.3%), including two attributed to APAP (0.1%) and none to IV-NAC. Of 64 patients who were treated with IV-NAC within 8 hours after APAP ingestion and had available ALT/AST data, two (3.1%) developed hepatotoxicity (AST/ALT > 1000 IU/L) compared with 32 (25%) of 128 patients receiving IV-NAC > 8 hours after APAP ingestion (p = 0.0002). A total of 26 patients (15.6%) receiving IV-NAC treatment within 8 hours after APAP ingestion had hospitalization stays > 48 hours compared with 70 (33.3%) receiving IV-NAC > 8 hours after ingestion (p < 0.0001). CONCLUSIONS: For patients with APAP overdose seen in the HATS database of New South Wales, Australia, in-hospital death was infrequent (< 1%) and hepatotoxicity was significantly less likely when IV-NAC was administered within 8 hours after APAP ingestion compared with longer intervals (p < 0.01). As a descriptive retrospective database analysis, this study could not exclude certain sources of bias, including temporal changes over the 16-year course of data collection in the use of IV-NAC and low ascertainment of mild, self-limiting reactions to IV-NAC.

Antiobesity efficacy of a novel cannabinoid-1 receptor inverse agonist, N-[(1S,2S)-3-(4-chlorophenyl)-2-(3-cyanophenyl)-1-methylpropyl]-2-methyl-2-[[5-(trifluoromethyl)pyridin-2-yl]oxy]propanamide (MK-0364), in rodents.

The cannabinoid-1 receptor (CB1R) has been implicated in the control of energy balance. To explore the pharmacological utility of CB1R inhibition for the treatment of obesity, we evaluated the efficacy of N-[(1S,2S)-3-(4-chlorophenyl)-2-(3-cyanophenyl)-1-methylpropyl]-2-methyl-2-[[5-(trifluoromethyl)pyridin-2-yl]oxy]propanamide (MK-0364) and determined the relationship between efficacy and brain CB1R occupancy in rodents. MK-0364 was shown to be a highly potent CB1R inverse agonist that inhibited the binding and functional activity of various agonists with a binding K(i) of 0.13 nM for the human CB1R in vitro. MK-0364 dose-dependently inhibited food intake and weight gain, with an acute minimum effective dose of 1 mg/kg in diet-induced obese (DIO) rats. CB1R mechanism-based effect was demonstrated for MK-0364 by its lack of efficacy in CB1R-deficient mice. Chronic treatment of DIO rats with MK-0364 dose-dependently led to significant weight loss with a minimum effective dose of 0.3 mg/kg (p.o.), or a plasma C(max) of 87 nM. Weight loss was accompanied by the loss of fat mass. Partial occupancy (30-40%) of brain CB1R by MK-0364 was sufficient to reduce body weight. The magnitude of weight loss was correlated with brain CB1R occupancy. The partial receptor occupancy requirement for efficacy was also consistent with the reduced food intake of the heterozygous mice carrying one disrupted allele of CB1R gene compared with the wild-type mice. These studies demonstrated that MK-0364 is a highly potent and selective CB1R inverse agonist and that it is orally active in rodent models of obesity.

Effects of mutations at conserved TM II residues on ligand binding and activation of mouse 5-HT6 receptor.

An aspartate residue (Asp-72) in the transmembrane helix II of mouse 5-hydroxytryptamine-6 receptor (5-HT6) is conserved among most G protein-coupled receptors. We have examined the functional significance of this residue by site-directed mutagenesis. A single Asp --> Ala (D72A) mutation resulted in an 8-fold decrease in apparent affinity for 5-HT, and a 60-fold reduction in EC50 value of agonist-induced stimulation of adenylyl cyclase. A F69L/T70I/D72A triple mutant showed a 2-fold reduction in apparent affinity for 5-HT but complete loss of adenylyl cyclase stimulation. Binding of SB-258585 (4-iodo-N-[4-methoxy-3-(4-methylpiperazin-1-yl)phenyl]benzene-sulfonamide), a selective 5-HT6 antagonist, was mildly affected (2- to 4-fold decrease in affinity) in the two mutants. Our data suggest that Asp-72 and additional residues toward the intracellular side of TM II have a limited role in ligand binding but are critical for functional activation of the 5-HT6 receptor.

Commercial enzyme immunoassay adapted for the detection of antibodies to hepatitis C virus in dried blood spots.

BACKGROUND: Dried blood spots (DBS) provide a convenient method for blood sample collection in many settings where the prevalence of infection with hepatitis C virus (HCV) is increasing. Consequently, HCV assays are required that produce reliable results using samples derived from DBS. OBJECTIVES AND STUDY DESIGN: The optimum buffer for the elution of samples from DBS was selected and the performance of a commercial enzyme immunoassay (EIA) was evaluated using these DBS eluates and paired plasma samples. RESULTS: DBS with paired plasma samples were compared using this modified commercial EIA, which was found to have an estimated sensitivity and specificity of approximately 100% for detecting anti-HCV antibodies in DBS. CONCLUSION: A DBS-based assay for the detection of antibodies to HCV will prove valuable for collecting epidemiological data in the field or in under resourced settings.

Calculating uncertainty of measurement for serology assays by use of precision and bias.

BACKGROUND: In many countries, regulatory authorities that use International Organization for Standardization Standards to assess laboratory competence require an estimate of the uncertainty of measurement (MU) of assay test results. This estimate can be determined by identifying all sources of variation, calculating the extent of variation, and using established methods to combine the uncertainty. Alternatively, laboratory staff may use existing data generated from evaluations, proficiency testing, or external run controls to determine MU. METHODS: A quality-control (QC) sample with low reactivity was tested by laboratories participating in a national QC program. The results of testing the QC sample were entered into a shared database by use of an Internet-based program, EDCNet. Using a statistical approach that accounts for imprecision and bias of test results, we estimated the MU of the laboratories. RESULTS: A total of 2167 test results of a single QC sample reported by 18 laboratories were analyzed, and the MU of 1 laboratory was estimated by the statistical model described. CONCLUSION: Using peer-group run control data, MU of serologic testing can be estimated by taking into account both imprecision and bias.

Kinetic therapy improves oxygenation in critically ill pediatric patients.

OBJECTIVE: To compare changes in oxygenation after manual turning and percussion (standard therapy) and after automated rotation and percussion (kinetic therapy). DESIGN: Randomized crossover trial. SETTING: General and cardiac pediatric intensive care units. PATIENTS: Intubated and mechanically ventilated pediatric patients who had an arterial catheter and no contraindications to using a PediDyne bed. INTERVENTIONS: Patients were placed on a PediDyne bed (Kinetic Concepts) and received 18 hrs blocks of standard and kinetic therapy in an order determined by randomization. MEASUREMENTS AND MAIN RESULTS: Arterial blood gases were measured every 2 hrs during each phase of therapy. Oxygenation index and arterial-alveolar oxygen tension difference [P(A-a)O(2)] were calculated. Indexes calculated at baseline and after each 18-hr phase of therapy were analyzed. Fifty patients were enrolled. Data from 15 patients were either not collected or not used due to reasons that included violation of protocol and inability to tolerate the therapies in the study. Indexes of oxygenation were not normally distributed and were compared using Wilcoxon signed rank testing. Both therapies led to improvements in oxygenation, but only those from kinetic therapy achieved statistical significance. In patients receiving kinetic therapy first, median oxygenation index decreased from 7.4 to 6.19 (p = .015). The median P(A-a)O(2) decreased from 165.2 to 126.4 (p = .023). There were continued improvements in oxygenation after the subsequent period of standard therapy, with the median oxygenation index decreasing to 5.52 and median P(A-a)O(2) decreasing to 116.0, but these changes were not significant (p = .365 and .121, respectively). When standard therapy was first, the median oxygenation index decreased from 8.83 to 8.71 and the median P(a-a)o(2) decreased from 195.4 to 186.6. Neither change was significant. Median oxygenation index after the subsequent period of kinetic therapy was significantly lower (7.91, p = .044) and median P(A-a)O(2) trended lower (143.4, p = .077). CONCLUSIONS: Kinetic therapy is more efficient than standard therapy at improving oxygenation and produces improvements in oxygenation that are more persistent.