Multiple Oral Doses Research Articles

In Silico Prediction of Andrographolide Dosage Regimens for COVID-19 Treatment.

Andrographolide (APE) has been used for COVID-19 treatment in various clinical settings in South-East Asia due to its benefits on reduction of viral clearance and prevention of disease progression. However, the limitation of APE clinical use is the high incidence of adverse events. The objective of this study was to find the optimal dosage regimens of APE for COVID-19 treatment. The whole-body physiologically-based pharmacokinetic (PBPK) models were constructed using data from the published articles and validated against clinical observations. The inhibitory effect of APE was determined for the potency of drug efficacy. For prevention of pneumonia, multiple oral doses such as 120[Formula: see text]mg for three doses, followed by 60[Formula: see text]mg three times daily for 4 consecutive days, or 200[Formula: see text]mg intravenous infusion at the rate of 20 mg/h once daily is advised in patients with mild COVID-19. For prevention of pneumonia and reduction of viral clearance time, the recommended dosage regimen is 500[Formula: see text]mg intravenous infusion at the rate of 25[Formula: see text]mg/h once daily in patients with mild-to-moderate COVID-19. One hundred virtual populations (50 males and 50 females) were simulated for oral and intravenous infusion formulations of APE. The eligible PBPK/PD models successfully predicted optimal dosage regimens and formulations of APE for prevention of disease progression and/or reduction of viral clearance time. Additionally, APE should be co-administered with other antiviral drugs to enhance therapeutic efficacy for COVID-19 treatment.

The impact of rifampicin on the pharmacokinetics of fuzuloparib in healthy Chinese male volunteers.

This clinical study was conducted to evaluate the impact of rifampicin on the pharmacokinetics of fuzuloparib. In this single-centre, single-arm, open-label, fixed-sequence study, healthy male subjects took a single 50 mg dose of fuzuloparib on two separate occasions: the first was on Day 1 as monotherapy, and the second was on Day 12 after oral administration of rifampicin 600 mg once daily for 8days. Series of blood samples were obtained before and after fuzuloparib administration at different time points: pre-dose, and 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 24, 36, 48 and 72 hours post-dose. All samples were examined using liquid chromatography with tandem mass spectrometry. PK parameters were estimated by using a non-compartmental method with Phoenix WinNonlin software. Safety was assessed by monitoring for changes in vital signs and laboratory tests, physical examinations, and incidences of adverse events (AEs). A total of 16 Chinese male subjects were enrolled. Of these, 16 and 15 cases were evaluable for PK analysis following administration with fuzuloparib alone and pretreatment with rifampicin, respectively. Pretreatment with rifampicin resulted in a statistically significant reduction in the systemic exposure to fuzuloparib. The treatment ratio and 90% confidence intervals (CIs) for AUC0-∞ and Cmax were 0.10 (0.095-0.115) and 0.32 (0.281-0.365), respectively. A single administration of fuzuloparib after multiple oral dosing of rifampicin was well-tolerated, without severe AEs. The exposure of fuzuloparib was dramatically decreased when pretreated with rifampicin. Strong CYP3A4 inducers should be avoided during fuzuloparib treatment.

Single and multiple ascending dose studies in healthy volunteers to assess the safety and PK of LY3372689, an inhibitor of the O‐GlcNAcase (OGA) enzyme

AbstractBackgroundLY3372689, an OGA enzyme inhibitor, is being developed as a potential treatment for tauopathies, including Alzheimer’s disease. OGA inhibition is proposed to delay the progression of tau‐related diseases by slowing the accumulation of hyper‐phosphorylated, insoluble tau filaments. We report the safety and pharmacokinetics (PK) of LY3372689 after single and multiple oral doses in healthy volunteers (HV).MethodThe single ascending dose (SAD) and multiple ascending dose (MAD) studies were single center, subject‐ and investigator‐blind, placebo‐controlled and randomized. In the SAD study [NCT03819270], 6 LY3372689 dose levels up to 16 mg and placebo were evaluated. In the MAD study [NCT04106206], LY3372689 (1, 3 and 7 mg) or placebo was given once daily (QD) for 14 days. Safety was assessed by adverse events (AE), safety laboratories, electrocardiograms, vital signs, physical exams, and neurological exams. Plasma pharmacokinetics (PK) was assessed in the SAD and MAD studies.ResultIn the SAD, 23 HV (15 males, 8 females; 22 – 63 years) participated, of which 18 HV completed. In the MAD, 40 HV (5 males, 35 females; 29 – 65 years) participated in the study, of which 39 HV completed. LY3372689 was generally well tolerated up to the highest dose in each study, and no serious AE were reported. In the SAD, 40 treatment‐emergent AEs (TEAEs) were reported, which were mostly mild in severity. The most common TEAEs were headache, nausea, pain in extremity, pain of skin, vessel puncture site pain, and limb discomfort. In the MAD, 42 TEAEs were reported, all of which were mild in severity. The most reported TEAE was headache. In both studies, there were no clinically significant changes in safety laboratories, including markers of inflammation, muscle injury, hormones and hepatoxicity. Following QD dosing of LY3372689, the tmax and t1/2 was about 1 hour and 6 hours, respectively, and LY3372689 exposure accumulation was minimal. Renal clearance was not a major contributor of LY3372689 elimination.ConclusionLY3372689 demonstrated an acceptable safety and PK profile following single and multiple doses of LY3372689 in HV. These results support investigation of LY3372689 in efficacy trials for tauopathies and help support dose selection for those trials.

Abstract 9741: Pharmacokinetics, Pharmacodynamics and Safety of Bempedoic Acid in a Phase 1 Clinical Trial in Healthy Japanese, Chinese and White Subjects

This study investigated the pharmacokinetics (PK), pharmacodynamics (PD), and safety of bempedoic acid (BA), an inhibitor of ATP-citrate lyase that significantly lowers LDL-C levels, after single and multiple oral dose administration in White and first-, second-, or third-generation Japanese and Chinese subjects living in the US. This double-blind, placebo-controlled study was conducted at a single US site in a total of 40 healthy subjects randomized (3:1) to receive BA or placebo. The PK, PD, and safety of BA were assessed in Japanese subjects after a single dose of BA 60, 120, or 180 mg; and in Japanese, Chinese, and White subjects (baseline LDL-C 70–190 mg/dL; not receiving a statin) after daily BA 180-mg dosing for 14 days. Enrolled subjects (28% female) ranged 23-59 years of age. In Japanese subjects, single dose maximum BA plasma concentrations increased proportionally, and AUC increased slightly greater than proportional to dose. After 14 days of BA 180 mg, mean estimates of BA elimination half-life were 25.2, 20.0 and 23.9 hours in Japanese, Chinese, and White subjects, respectively. Active metabolite ESP15228 AUC exposures were approximately 20% of BA across subjects. Mean oral clearance (CL/F) in Japanese (0.494 L/h) and Chinese (0.592 L/h) subjects was 29% and 15% less and volume of distribution (V z /F) in Japanese (18.0 L) and Chinese (19.2 L) subjects was 32% and 27% less than in White subjects, respectively. Differences in CL/F and V z /F were decreased after body weight (BW) normalization, with higher mean BW for White subjects (80.6 kg) observed relative to Japanese (67.4 kg) and Chinese (74.1 kg) subjects. A reduction in fasting LDL-C, non-HDL-C, and hsCRP was observed with BA. The mean (SD) percent change from baseline in LDL-C among subjects (n=6 each) receiving BA 180 mg was –29% (14) for Japanese subjects, –39% (8) for Chinese subjects, and –17% (28) for White subjects compared with +17% (21) for subjects receiving placebo. Results from this study suggest that administration of BA 180 mg once daily over 14 days markedly reduced LDL-C and was well tolerated in all subjects. PK differences, largely explained after normalizing CL/F and V z /F by subject BW, are not expected to result in clinically meaningful differences in the efficacy or safety profiles of BA.

Target engagement of the first-in-class CXCR7 antagonist ACT-1004-1239 following multiple-dose administration in mice and humans

Antagonism of the chemokine receptor CXCR7 has shown promising effects in diverse disease areas through modulation of its ligands, CXCL11 and CXCL12. Preclinical data of the first-in-class CXCR7 antagonist, ACT-1004-1239, showed efficacy in animal models of multiple sclerosis and acute lung injury. In healthy humans, single-dose administration of ACT-1004-1239 revealed a favorable clinical profile. Here, we report the target engagement of ACT-1004-1239 in healthy mice and humans after multiple doses using CXCL11 and CXCL12 as biomarkers. In addition, safety/tolerability, concentration-QTc relationship, and pharmacokinetics (PK) were assessed in a randomized, double-blind, placebo-controlled Phase 1 clinical study. Multiple-dose ACT-1004-1239 dose-dependently increased CXCL12 plasma concentration across the investigated dose range in mice and humans (mice: 1–100 mg/kg b.i.d.; humans: 30–200 mg o.d.) when compared to vehicle/placebo demonstrating target engagement. Mouse and human PK/PD models predicted that CXCL12 concentration approached a plateau within these dose ranges. In humans, ACT-1004-1239 was rapidly absorbed (tmax: 1.75–3.01 h) and the terminal t1/2 was approximately 19 h. Steady-state conditions were reached by Day 3 with an accumulation index of 1.2. Female subjects had overall higher exposure compared to males. Multiple-dose ACT-1004-1239 was well tolerated up to 200 mg once daily in humans. There was no evidence of ACT-1004-1239-mediated QTc interval prolongation. Overall, multiple oral doses of ACT-1004-1239 showed target engagement with CXCR7 in healthy mice and humans, therefore, assessment of CXCL12 as translational tool for further investigations in patients is warranted. Favorable safety/tolerability and PK profiles allow for further clinical development.

Pharmacokinetic Parameters and Tissue Withdrawal Intervals for Sheep Administered Multiple Oral Doses of Meloxicam.

Simple SummaryMeloxicam is an anti-inflammatory drug used to treat pain and inflammation in ruminants including sheep, and pharmacokinetic studies are needed to protect the food supply from drug residues after use in food-producing animals. This study estimated plasma pharmacokinetic parameters and meat withdrawal intervals (WDI) for market sheep after multiple daily oral doses of meloxicam. Single and multiple dose plasma pharmacokinetic studies, a multi-dose tissue depletion study, and a follow-up study to investigate if events prior to slaughter were associated with differences in plasma meloxicam concentrations, all using sample data collected after completion of dosing, were completed. Using regulatory agency methods for calculating withdrawal times, an estimated WDI of at least 10 d following the last dose is recommended for market lambs treated with ten daily oral 1 mg/kg doses of meloxicam tablets suspended in water. The effect of events surrounding slaughter on plasma meloxicam concentrations in lambs is unknown but should be considered if plasma samples are obtained immediately prior to or during the slaughter process and used for pharmacokinetic investigations.Meloxicam is an anti-inflammatory drug used to treat pain and inflammation in ruminants including sheep, and pharmacokinetic studies are needed to protect the food supply from drug residues after use in food-producing animals. This study estimated plasma pharmacokinetic parameters and meat withdrawal intervals (WDI) for market sheep after multiple daily oral doses of meloxicam. Single and multiple dose plasma pharmacokinetic studies, a multi-dose tissue depletion study, and a follow-up study to investigate if events prior to slaughter were associated with differences in plasma meloxicam concentrations, all using sample data collected after completion of dosing, were completed. Using regulatory agency methods for calculating withdrawal times, an estimated WDI of at least 10 d following the last dose is recommended for market lambs treated with 10 daily oral 1 mg/kg doses of meloxicam tablets suspended in water. The effect of events surrounding slaughter on plasma meloxicam concentrations in lambs is unknown but should be considered if plasma samples are obtained immediately prior to or during the slaughter process and used for pharmacokinetic investigations.

PD27-07 BEDSIDE TO BENCHTOP RESEARCH UNCOVERS THE FUNCTIONAL ROLE OF HYPERPOLARIZATION-ACTIVATED CYCLIC NUCLEOTIDE-GATED GATED (HCN) CHANNELS IN AGING BLADDER PHENOTYPE

You have accessJournal of UrologyUrodynamics/Lower Urinary Tract Dysfunction/Female Pelvic Medicine: Basic Research & Pathophysiology (PD27)1 Sep 2021PD27-07 BEDSIDE TO BENCHTOP RESEARCH UNCOVERS THE FUNCTIONAL ROLE OF HYPERPOLARIZATION-ACTIVATED CYCLIC NUCLEOTIDE-GATED GATED (HCN) CHANNELS IN AGING BLADDER PHENOTYPE Nishant Singh, Irina Zabbarova, Anthony Kanai, Christopher Chermansky, Naoki Yoshimura, and Pradeep Tyagi Nishant SinghNishant Singh More articles by this author , Irina ZabbarovaIrina Zabbarova More articles by this author , Anthony KanaiAnthony Kanai More articles by this author , Christopher ChermanskyChristopher Chermansky More articles by this author , Naoki YoshimuraNaoki Yoshimura More articles by this author , and Pradeep TyagiPradeep Tyagi More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002020.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The aging bladder phenotype in detrusor overactivity, detrusor underactivity or detrusor hyperactivity with impaired contractility patients is characterized by detrusor instability with or without the loss of bladder volume sensitivity. Since separate studies reported age related downregulation of Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in mouse and human bladder, we examined the functional significance of age related reduction in HCN activity with multiple oral dosing of FDA approved HCN blocker, Ivabradine. METHODS: Aged male Fisher 344 rats (n=15) and young rats of both genders (n=15) were left untreated or treated daily with oral gavage of either vehicle or Ivabradine 6mg/kg (n=5) for 7 days prior to assessing nocturnal urination followed by awake cystometry on 7th day and quantitative RT-PCR and Western blot of HCN subtypes of untreated aged and young rats. RESULTS: Untreated aged aged rats (n=10) voided nearly double the volume of individual voids of young rats at night time (0.82±0.22 mL vs 0.41±0.12 mL, p<0.05), which was confirmed by a significant increase (p<0.05) in the micturition volume threshold (VT) in awake cystometry of aged rats. Increase in VT of aged rats coincided with a doubling of non-voiding contraction (NVC) frequency (p<0.05) while maximum voiding pressure (MVP) did not change with age. The age- related alterations in cystometry parameters correlated with the significant downregulation of cAMP sensitive HCN1and HCN2 subtype (40%) and the upregulation of cAMP insensitive HCN3 (60%) subtype. Ivabradine treatment significantly increased the VT (p<0.005), NVC frequency (p<0.001) and MVP (p<0.0001) in young and aged rats to different extents. CONCLUSIONS: A critical role for the altered bladder expression of HCN subtypes in the manifestation of aging bladder phenotype is supported by the dramatic changes in the bladder function following pharmacological blockade of HCN channels in young rats. The dramatic effect of Ivabradine on VT and MVP of aged rats in this bedside to benchtop research provides a basis for the therapeutic benefit of Ivabradine on detrusor underactivity of a male patient (Int Urol Nephrol, 40: 333, 2008). Source of Funding: NIA- AG062971 © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e446-e446 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Nishant Singh More articles by this author Irina Zabbarova More articles by this author Anthony Kanai More articles by this author Christopher Chermansky More articles by this author Naoki Yoshimura More articles by this author Pradeep Tyagi More articles by this author Expand All Advertisement Loading ...

A Method to Custom-build Equations of Drug Concentration as a Function of Real Time in the One-Compartment Open Model and Their Application in Multiple Intravenous Bolus and Multiple Oral Doses

A method to custom-build expressions of drug concentration as a function of total time in a one-compartment pharmacokinetic model for multiple-dose schedules is developed and successfully applied in four dosing schedules that combined administration of multiple IV bolus and oral maintenance and loading doses. The method consists of writing the terms of the mathematical sequence from the analytical solutions to drug concentration using total time, instead of time within dosing interval, extracting the pattern of the respective sequences, and finally, determining the partial sums of the series that relate to drug concentration to dose number and real-time, for each particular administration route and dosing schedule. Multiple subroutines written in Fortran language demonstrated the potential of these equations to investigate the effect of dose size on peak plasma drug concentration and peak time after multiple oral administrations and for calculating and refining experimentally determined time-dependent pharmacokinetic parameters such as non steady-state average concentration values and Area Under the Curve (AUC). It is shown that the only truly independent of dose size peak time is that of the first oral dose (). A mathematical expression was derived that relates the time to reach non steady-state peak times after multiple oral doses to the absorption and elimination rate constants for the first time. For repetitive oral dose administration, the will always be the longest peak time, while the shortest time to reach maximum plasma drug concentration will be at steady-state conditions.

Physiologically based pharmacokinetic modelling to predict the clinical effect of CYP3A inhibitors/inducers on esaxerenone pharmacokinetics in healthy subjects and subjects with hepatic impairment

PurposeEsaxerenone is a novel, oral, nonsteroidal treatment for hypertension. Physiologically based pharmacokinetic (PBPK) modelling was performed to predict the drug–drug interaction (DDI) effect of cytochrome P450 (CYP)3A modulators on esaxerenone pharmacokinetics in healthy subjects and subjects with hepatic impairment.MethodsIn our PBPK model, the fraction of esaxerenone metabolised by CYP3A was estimated from mass-balance data and verified and optimised by clinical DDI study results with strong CYP3A modulators. The model was also verified by the observed pharmacokinetics after multiple oral dosing and by the effect of hepatic impairment on esaxerenone pharmacokinetics. The model was applied to predict the DDI effects on esaxerenone pharmacokinetics with untested CYP3A modulators in healthy subjects and with strong CYP3A modulators in subjects with hepatic impairment.ResultsThe PBPK model well described esaxerenone pharmacokinetics after multiple oral dosing. The predicted fold changes in esaxerenone plasma exposure after coadministration with strong CYP3A modulators were comparable with the observed data (1.53-fold with itraconazole and 0.31-fold with rifampicin). Predicted DDIs with untested moderate CYP3A modulators were less than the observed DDI with strong CYP3A modulators. The PBPK model also described the effect of hepatic impairment on esaxerenone plasma exposure. The predicted DDI results with strong CYP3A modulators in subjects with hepatic impairment indicate that, for concomitant use of CYP3A modulators, caution is advised for subjects with hepatic impairment, as is for healthy subjects.ConclusionThe PBPK model developed predicted esaxerenone pharmacokinetics and DDIs and informed concurrent use of esaxerenone with CYP3A modulators.

Pharmacokinetics, Tolerability, and Safety of Single and Multiple Omecamtiv Mecarbil Doses in Healthy Japanese and Caucasian Subjects.

Omecamtiv mecarbil (OM) is a cardiac myosin activator under development for the treatment of heart failure. The pharmacokinetics of single and multiple doses of OM were investigated in healthy Japanese subjects in two clinical studies. Study 1 (n = 36) evaluated the bioavailability and pharmacokinetics after intravenous infusion (15 mg/h for 4 h) and an oral modified release (MR) tablet in healthy Japanese and Caucasian subjects using 25 mg single and multiple doses and 50 mg single dose. Study 2 (n = 50) evaluated the pharmacokinetics of OM with multiple oral doses of 25 mg MR tablets twice a day (BID) followed by up-titration to either 37.5 mg or 50 mg BID in healthy Japanese subjects. In Study 1, the maximum observed plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC) from time 0 to infinity (AUCinf) in Japanese subjects after a single oral dose of 50 mg were twice that at the 25 mg dose, consistent with that observed in Caucasian subjects. Following single oral doses of 25 mg and 50 mg, absolute bioavailability was 56.5% and 59.2% for Japanese subjects and 63.1 and 83.6% for Caucasian subjects, respectively. No ethnic differences were observed in the pharmacokinetics of OM and its metabolites following single and multiple doses of 25 mg and 50 mg. In Study 2, the mean accumulation ratios based on AUC from 0 to 12 h (AUC12) were approximately four-fold from day 1 to day 8 and from day 20 to day 27 across ethnic groups. The mean ratios of Cmax to predose concentrations (Cpredose) ranged from 1.25 to 1.38 across subgroups. OM showed consistent and predictable pharmacokinetics after multiple dosing in Japanese subjects.

Population pharmacokinetic analysis of ulotaront in subjects with schizophrenia.

Ulotaront (SEP‐363856) is a trace amine–associated receptor 1 agonist with 5‐HT1A agonist activity in phase III development for the treatment of schizophrenia. The efficacy of ulotaront is not mediated by blockade of D2 or 5‐HT2A receptors. The aim of this study was to evaluate the population pharmacokinetics (PopPKs) of ulotaront in adult subjects using pooled data from seven phase I studies, one phase II acute study, and one 6‐month extension study. Single and multiple (up to 7 days) oral doses (5–150 mg/day) were studied in both healthy adult subjects (with intensive serial plasma sampling) and adult patients with schizophrenia (some with intensive and some with sparse plasma sampling). Ulotaront was well‐absorbed and exhibited dose‐proportionality in doses ranging from 10 to 100 mg, in mean maximum concentration, area under the concentration‐time curve, and minimum concentration. Moderate interindividual variability was observed in concentration‐time profiles. The estimated median time to maximal concentration was 2.8 h and the median effective half‐life was 7 h, corresponding to an exposure accumulation ratio of 1.10 at steady‐state with daily dosing. There was no indication of time‐dependent changes in PKs after up to 12 weeks of daily dose administration. No clinically meaningful effects on ulotaront PK parameters were observed based on race, age, sex, formulation (capsule or tablet), or clinical status (healthy volunteer vs. patient with schizophrenia); body weight was the only meaningful covariate.

Metabolism is not a Major Contributor to the Toxicity of Piperaquine, a Long-acting Antimalarial Agent in Artemisinin-based Combination Therapy.

Hepatocellular damage has been reported for the antimalarial piperaquine (PQ) in the clinic after cumulative doses. The role of metabolism in PQ toxicity was evaluated, and the mechanism mediating PQ hepatotoxicity was investigated. The toxicity of PQ and its major metabolite (PQ N-oxide; M1) in mice was evaluated in terms of serum biochemical parameters. The role of metabolism in PQ toxicity was investigated in mice pretreated with an inhibitor of CYP450 (ABT) and/or FMO enzyme (MMI). The dose-dependent pharmacokinetics of PQ and M1 were studied in mice. Histopathological examination was performed to reveal the mechanism mediating PQ hepatotoxicity. Serum biochemical levels (ALT and BUN) increased significantly (P < 0.05) in mice after three-day oral doses of PQ (> 200 mg/kg/day), indicating hepatotoxicity and nephrotoxicity of PQ at a high dose. Weaker toxicity was observed for M1. Pretreatment with ABT and/or MMI did not increase PQ toxicity. PQ and M1 showed linear pharmacokinetics in mice after a single oral dose, and multiple oral doses led to their cumulative exposures. Histopathological examination showed that a high dose of PQ (> 200 mg/kg/day for three days) could induce hepatocyte apoptosis. The mRNA levels of targets in NF-κB and p53 pathways could be up-regulated by 2-30-fold in mice by PQ or M1. PQ metabolism led to detoxification of PQ, but there was a low possibility of altered toxicity induced by metabolism inhibition. The hepatotoxicity of PQ and its N-oxidation metabolite was partly mediated by NF-κB inflammatory pathway and p53 apoptosis pathway.

Preclinical Evaluation of the Effects of Trazpiroben (TAK-906), a Novel, Potent Dopamine D2/D3 Receptor Antagonist for the Management of Gastroparesis.

Current therapies for gastroparesis metoclopramide and domperidone carry risks of extrapyramidal symptoms and life-threatening cardiac arrhythmias. Trazpiroben, a novel, potent dopamine D2/D3 receptor antagonist, has low brain permeation and very low affinity for human ether-à-go-go-related gene (hERG) channel inhibition, potentially improving on safety profiles of existing therapies. Trazpiroben demonstrated the following receptor affinities: high for D2 and D3, moderate for D4, and minimal for D1 and D5 It demonstrated moderate affinity for adrenergic α 1B (α 1B) and 5-hydroxytryptamine (5HT) 2A receptors and low potential for off-target adverse events (AEs). Trazpiroben potently inhibited dopamine-activated D2L receptor activation of cognate G-proteins in human embryonic kidney 293 cell membranes and was a neutral D2L receptor antagonist. In vivo, trazpiroben dose-dependently increased prolactin release in orally dosed rat (0.1-1 mg/kg). Additionally, multiple oral doses in the rat (100 mg/kg) and dog (50 mg/kg) for 3 days produced robust plasma exposures and prolactin increases in both species. Trazpiroben inhibited retching/vomiting in the dog with apomorphine-induced emesis with a potency (0.1-1 mg/kg) like that of trazpiroben-mediated prolactin increases in rat. Oral trazpiroben (1, 10, and 30 mg/kg) did not affect rat rotarod performance, suggesting low brain penetration. Trazpiroben concentrations were low in cerebrospinal fluid versus plasma after multiple oral doses for 4 days in rat and dog. Trazpiroben weakly inhibited the hERG channel current (concentration causing half-maximal inhibition of control-specific binding of 15.6 µM), indicating little potential for disrupting cardiac rhythm. Overall, trazpiroben is a potent D2/D3 receptor antagonist designed to avoid the serious potential AEs associated with current gastroparesis therapies. SIGNIFICANCE STATEMENT: Trazpiroben is a novel, potent dopamine D2/D3 selective receptor antagonist designed to avoid adverse effects associated with the current pharmacological therapies metoclopramide and domperidone. Preclinical studies have demonstrated low brain penetration and weak affinity for the hERG channel, indicating that trazpiroben is not expected to be associated with central nervous system or cardiovascular safety issues. With these pharmacological properties, trazpiroben may represent a viable new treatment option for gastroparesis because of a potentially improved safety profile relative to existing therapies.

Pharmacokinetics of a New, Once-Daily, Sustained-release Pregabalin Tablet in Healthy Male Volunteers

PurposeA new sustained-release (SR) pregabalin formulation (YHD1119) designed for once-daily dosing has recently been developed to improve patient adherence. This study aimed to compare the pharmacokinetics of pregabalin SR and immediate-release (IR) formulations after multiple oral doses and to assess the effect of food on the pharmacokinetic profile of the pregabalin SR formulation after a single dose in healthy individuals. MethodsTwo clinical trials were conducted: a randomized, open-label, multiple-dose, 2-treatment, 2-period crossover study to evaluate the steady-state pharmacokinetic properties of SR treatment (pregabalin SR 300 mg once daily for 3 days) and IR treatment (pregabalin IR 150 mg twice daily for 3 days) under fed conditions and a randomized, open-label, single-dose, 2-treatment, 2-period, crossover study to evaluate the effect of food intake on the pharmacokinetic properties of the pregabalin SR formulation. Plasma concentrations of pregabalin were measured using LC-MS/MS. The AUC and Cmax for pregabalin were calculated using noncompartmental method and compared between treatments in each study. FindingsThirty-one individuals in the bioequivalence study and 23 in the food effect study completed the pharmacokinetic sampling. The geometric mean ratios of Cmax,ss and AUC0–τ between the SR and IR formulations were 1.1642 (90% CI, 1.1043–1.2272) and 0.9704 (90% CI, 0.9372–1.0047), respectively. The geometric mean ratios of Cmax and AUC0–last between the SR formulation in the fed state and in the fasted state were 1.6514 (90% CI, 1.3820-1.9732) and 1.7899 (90%CI, 1.4499-2.2097), respectively. ImplicationsThe bioavailability of the pregabalin SR 300 mg formulation is increased if taken with a high-fat meal. Once-daily pregabalin SR 300 mg is bioequivalent to twice-daily pregabalin IR 150 mg under fed conditions at steady state. The pregabalin SR formulation is expected to improve patient adherence. ClinicalTrials.gov identifiers: NCT02783183 (bioequivalence study) and NCT03191136 (food effect study).

Physiologically Based Pharmacokinetic (PBPK) Modeling for Betrixaban and the Impact of P-Glycoprotein Inhibition on Betrixaban Pharmacokinetics

Introduction: Betrixaban is a factor Xa inhibitor indicated for the prophylaxis of venous thromboembolism (VTE) in adult patients hospitalized for an acute medical illness. A physiologically based pharmacokinetic (PBPK) model for betrixaban provided the mechanistic understanding of the contribution of P-glycoprotein (P-gp), as well as CYP3A4, to the disposition of betrixaban, and predictions of the effects of drug-drug interactions mediated by P-gp and/or CYP3A4. The PBPK model specifically evaluated contribution of the interaction with the P-gp transporter to the disposition of betrixaban, as well as the effects of co-administration of P-gp inhibitors (ketoconazole, verapamil, clarithromycin) on betrixaban pharmacokinetics (PK). Further, in vitro and clinical studies confirmed the lack of a significant interaction of betrixaban with CYP3A4.Methods: The base PBPK model was developed using physiochemical data, in vitro metabolism andtransport data generated using recombinant CYP enzymes and human hepatocytes, and relevant clinical data (eg, observed renal clearance). The model was verified by comparing model predictions with PK data derived from single oral doses of betrixaban (from 80 to 550 mg) in healthy volunteers. The combined contribution of intestinal and hepatic P-gp transport to the disposition of betrixaban was verified by comparing model predictions to the observed ketoconazole and verapamil clinical drug-drug interaction data from healthy volunteers. The verified PBPK model was prospectively employed to predict the impact of a strong P-gp inhibitor (clarithromycin) and a moderate P-gp inhibitor (diltiazem) on betrixaban PK, and to predict the impact of food intake on betrixaban PK and compare it against the observed data in phase 3 studies. The Simcyp Population-Based Simulator (v15 release 1) was used for all simulations.Results: The major clearance pathway for betrixaban was biliary clearance (assigned to hepatic P-gp) as scaled from uptake data generated in human hepatocytes, accounting for ~80% of clearance after IV administration (CLIV). CYP3A4 played virtually no role in the disposition of betrixaban. The base PBPK model incorporating an intestinal P-gp component within the ADAM model resulted in simulations that predicted concentrations very close to the clinically observed pharmacokinetic non-linearity arising from multiple oral dosing of betrixaban in the dose range of 80 to 550 mg in healthy volunteers. The model predicted that the inhibition of intestinal and hepatic P-gp transport of betrixaban would result in the geometric mean area under the curve (AUC) and maximal concentration (Cmax) ratios due to concurrent ketoconazole treatment of 2.4 and 2.5, respectively, which were consistent with the observed ratios of 2.1 and 2.3. The predicted betrixaban geometric mean AUC and Cmax ratios due to concurrent verapamil treatment were 2.3 and 3.1, respectively, compared with the observed ratios of 3.0 and 4.7. The model qualitatively predicted the negative impact of food intake on betrixaban exposure (Figure). The predicted AUC and Cmax for patients treated with betrixaban in the fed state in the phase 3 study were within 1.5-fold of the observed values. In the final application of the PBPK model to predict the impact of the strong and moderate P-gp inhibitors, the predicted AUC and Cmax ratios due to clarithromycin treatment were 3.76 and 3.11, respectively, and due to diltiazem treatment were 1.1 and 1.1, respectively.Conclusions: The PBPK model for betrixaban adequately predicted the clinically observed PK non-linearity and accounted for the observed drug-drug interaction effects due to co-administration of betrixaban with ketoconazole and verapamil in healthy volunteers. The PBPK model did not predict a role for CYP3A4 in the clearance of betrixaban and accurately predicted a negative food effect. Intestinal and hepatic P-gp were identified as major contributors to the observed non-linearity in the kinetics of betrixaban and observed drug-drug interaction effects with P-gp inhibitors. [Display omitted] DisclosuresLeeds:Portola Pharmaceuticals, Inc.: Employment, Equity Ownership. Ke:Portola Pharmaceuticals, Inc.: Consultancy. Rowland Yeo:Portola Pharmaceuticals, Inc.: Consultancy. Curnutte:Portola Pharmaceuticals, Inc.: Employment, Equity Ownership. Conley:Portola Pharmaceuticals, Inc.: Employment, Equity Ownership, Patents & Royalties.

MM-013 Phase 2, Multicenter Study of Pomalidomide (POM) Plus Low-Dose Dexamethasone (LoDEX) in Patients (pts) with Relapsed/Refractory Multiple Myeloma (RRMM) and Renal Impairment (RI): Pharmacokinetics (PK) Analysis

MM-013 Phase 2, Multicenter Study of Pomalidomide (POM) Plus Low-Dose Dexamethasone (LoDEX) in Patients (pts) with Relapsed/Refractory Multiple Myeloma (RRMM) and Renal Impairment (RI): Pharmacokinetics (PK) Analysis

Pharmacokinetics of enflicoxib in dogs: Effects of prandial state and repeated administration.

The pharmacokinetics of enflicoxib were evaluated in both a bioavailability study and a multi‐dose safety study in Beagle dogs. When administered at 8 mg/kg, the oral bioavailability (F) of enflicoxib was 44.1% in fasted dogs, but F increased to 63.4% under post prandial conditions. Enflicoxib is rapidly metabolised. After the first 48 h, the plasma levels of its pyrazol metabolite were much higher and persistent than those of the parent compound. Following intravenous administration, the total body plasma clearance of enflicoxib was of 140 ml/h/kg and the volume of distribution based on the terminal phase was 4 L/kg. Plasma protein binding for both compounds was approximately 99%. The blood to plasma ratio for the pyrazol metabolite showed saturable kinetics with higher blood cell affinity at lower total blood concentrations which ranged from 2.49 to 0.95 for concentrations from 1 to 15 µg/ml. Enflicoxib and its pyrazol metabolite exhibited dose‐proportional pharmacokinetics for single oral doses of 8–40 mg⁄kg and for multiple oral doses of 4–20 mg⁄kg. After 7 months of repeated weekly administrations, pre‐dose plasma concentrations (Cmin,ss) remained constant throughout the study, with no trend to any significant over‐accumulation. The mean terminal elimination half‐life (t½) was 20 h for enflicoxib and 17 days for the pyrazol metabolite. The pharmacokinetic profile of enflicoxib and its pyrazol metabolite in dogs supports the proposed dosing regimen in which doses are separated by 1 week.

Rupatadine Oral Solution Titration by Body Weight in Paediatric Patients Suffering from Allergic Rhinitis: A Population Pharmacokinetic Study.

BackgroundAllergic rhinitis (AR) and chronic urticaria, both are treated in children with doses of second generation of antihistamines that have been mostly based on extrapolation of data obtained in adults. The objectives of this work were to develop a model to explain the pharmacokinetics (PK) of rupatadine, a second generation antihistamine, administered to children 2−11 years old and to calculate the non-compartmental PK parameters for two groups of age (2–5 and 6–11 years old) based on the individual Bayesian estimates from the selected model.MethodsData from two PK studies with rupatadine oral solution (1 mg/mL) were pooled: Study A, an extensive blood sampling study performed in 11 children (6–11 years old) who received a single oral dose of rupatadine; and Study B, a sparse blood sampling study in 40 children (2–5 years old) receiving multiple oral doses. A simultaneous population PK model was developed using data available for all children. Using individual Bayesian estimates from the selected model, steady-state plasma concentrations for both studies were simulated and the non-parametric PK parameters were calculated for two age groups: 2–5 years (subgroup I) and 6–11 years (subgroup II).ResultsA two-compartment model with first-order absorption and elimination with clearance depending on body weight, better described the PK of rupatadine for 2–11 year old children. The plasma clearance dependence on weight was linear. The mean (SD) non-compartment PK parameters calculated using simulated plasma profiles at steady state were: Cmax, 2.54 (1.26) vs 1.96 (0.52) ng/mL; AUC0-24h, 10.74 (3.09) vs 10.38 (4.31) ng/mL/h; and t1/2, 12.28 (3.09) vs 15.94 (4.09) h, for children 6–11 and 2–5 years old, respectively.ConclusionsThe PK of rupatadine depends on the weight of paediatric patients but not on their age. The dosage strategy adjusted by body weight in children 2–11 years old (2.5 mL if weight 10–25 kg, and 5 mL if ≥ 25 kg) provides similar exposure between the two groups of age, and to that obtained in adults with the 10 mg dose tablet formulation.

POS0672 FIRST-IN-HUMAN STUDY OF GS-5718, AN ORAL IRAK-4 INHIBITOR, IN HEALTHY SUBJECTS: PHARMACOKINETICS, SAFETY, TOLERABILITY, AND ASSESSMENT OF EFFECT OF FOOD AND ACID REDUCING AGENTS ON EXPOSURE

Background:GS-5718 is a potent and selective interleukin-1 receptor-associated kinase 4 (IRAK4) inhibitor in clinical development for treatment of inflammatory diseases.Objectives:The aim of this first-in-human study was to evaluate the pharmacokinetics, safety, and tolerability of GS-5718; and the effect of food and acid-reducing agents (ARA) on GS-5718 pharmacokinetics in healthy subjects.Methods:This was a blinded, randomized, placebo-controlled, single and multiple (once daily for 10 days) oral dose study. Healthy male and female subjects were enrolled in ascending dose cohorts and randomized to receive GS-5718 (15, 50 or 150 mg) or placebo. GS-5718 was administered fasted in the single ascending dose cohorts, and under fed conditions (standard meal) in the multiple dose cohorts. The effects of a high-fat meal and omeprazole (a representative ARA) on GS-5718 50 mg dose pharmacokinetics were also evaluated. Serial blood samples were collected and GS-5718 pharmacokinetic parameters were characterized. Safety was assessed by review of adverse events (AEs), clinical laboratory tests, and vital signs.Results:A total of 74 subjects (n = 62 GS-5718; n = 12 placebo) enrolled and completed study drug treatments in this study. GS-5718 was generally well tolerated at all evaluated dose levels; AEs were mild in severity and no dose-limiting toxicities, serious AEs, nor clinically relevant electrocardiogram or vital sign abnormalities were observed in subjects administered GS-5718. GS-5718 exposure was approximately dose proportional across the evaluated multiple ascending dose range. GS-5718 showed low-to-moderate pharmacokinetic variability with median half-life of 25 to 33 hours and 1.6 to 2.4- fold accumulation at steady-state, which was achieved by Day 5-7 of dosing. Food had no clinically meaningful impact on GS-5718 exposure (AUC and Cmax) at the 50 mg dose. Co-administration of omeprazole with GS-5718 reduced GS-5718 exposure (AUC and Cmax) by 23% and 43%, respectively, at the 50 mg dose.Conclusion:GS-5718, administered once daily, was well tolerated following single or multiple dosing up to 150 mg. The pharmacokinetic and safety profile of GS-5718 support the further development in inflammatory diseases with once-daily administrations.Disclosure of Interests:Kacey Anderson Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Chia-Hsiang Hsueh Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Oksana Gurtovaya Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Anubhav Mathur Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, James Taylor Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Adrian Serone Shareholder of: Gilead Sciences, Employee of: Gilead Sciences, Ahmed A. Othman Shareholder of: Gilead Sciences, Employee of: Gilead Sciences

Single- and Multiple-Dose Pharmacokinetics and Pharmacodynamics of PN-943, a Gastrointestinal-Restricted Oral Peptide Antagonist of α4β7, in Healthy Volunteers.

PN‐943 is an orally stable, gastrointestinal‐restricted peptide that binds specifically to α4ß7 integrin on leukocytes, blocking leukocyte trafficking to and activation in the gut, inhibiting colon inflammation and reducing signs and symptoms of active ulcerative colitis. Two pharmacokinetic/pharmacodynamic studies were conducted in healthy volunteers. Study 1 was a first‐in‐human study with 40 male subjects receiving PN‐943, 100 to 1400 mg or placebo, as single doses and 57 male subjects receiving PN‐943, 100 to 1000 mg or placebo, as multiple doses. Study 2 was a randomized, crossover study comparing multiple doses of 450‐mg PN‐943 twice daily as a liquid solution and as an immediate‐release tablet in 10 subjects. No subjects discontinued due to treatment‐emergent adverse events. Consistent with the gastrointestinal‐restricted nature of the peptide, systemic exposure was minimal; there was an approximate dose‐proportional increase in area under the plasma concentration–time curve. There was minimal accumulation with once‐daily dosing and an absence of time‐dependent changes in pharmacokinetics. Administration of PN‐943 after a high‐fat meal reduced peak plasma concentration and area under the plasma concentration–time curve. There was minimal (<0.1%) urinary excretion of intact drug, and there was a dose‐related increase in fecal excretion of intact PN‐943. Dose‐dependent increases in blood receptor occupancy and reduction in blood receptor expression were observed, supporting target engagement. Twice‐daily dosing resulted in sustained receptor occupancy with low plasma fluctuations (143%). PN‐943 was generally well tolerated following single and multiple oral doses with low systemic exposure. Twice‐daily dosing resulted in sustained pharmacokinetics and pharmacodynamics, supporting further investigation in efficacy studies.