A Population Pharmacokinetic Study to Compare a Novel Empagliflozin L-Proline Formulation with Its Conventional Formulation in Healthy Subjects

Empagliflozin is a sodium-glucose cotransporter 2 (SGLT2) inhibitor that is commonly used for the treatment of type 2 diabetes mellitus (T2DM). CKD-370 was newly developed as a cocrystal formulation of empagliflozin with co-former L-proline, which has been confirmed to be bioequivalent in South Korea. This study aimed to quantify the differences in the absorption phase and pharmacokinetic (PK) parameters of two empagliflozin formulations in healthy subjects by using population PK analysis. The plasma concentration data of empagliflozin were obtained from two randomized, open-label, crossover, phase 1 clinical studies in healthy Korean subjects after a single-dose administration. A population PK model was constructed by using a nonlinear mixed-effects (NLME) approach (Monolix Suite 2021R1). Interindividual variability (IIV) and interoccasion variability (IOV) were investigated. The final model was evaluated by goodness-of-fit (GOF) diagnostic plots, visual predictive checks (VPCs), prediction errors, and bootstrapping. The PK of empagliflozin was adequately described with a two-compartment combined transit compartment model with first-order absorption and elimination. Log-transformed body weight significantly influenced systemic clearance (CL) and the volume of distribution in the peripheral compartment (V2) of empagliflozin. GOF plots, VPCs, prediction errors, and the bootstrapping of the final model suggested that the proposed model was adequate and robust, with good precision at different dose strengths. The cocrystal form did not affect the absorption phase of the drug, and the PK parameters were not affected by the different treatments.

Establishment of Advanced Regulatory Innovation for Clinical Trials Transformation (ARICTT): a multi-stakeholder public-private partnership-based organization to accelerate the transformation of clinical trials

Clinical trials have evolved with digital technologies and tend towards patient-centricity. A multi-stakeholder approach is needed to address the emerging complexities in clinical trials. In particular, the introduction of digital technologies and an emphasis on patient-centricity are the major trends in clinical trials. In response, we established a public-private partnership-based organization named Advanced Regulatory Innovation for Clinical Trials Transformation (ARICTT). Eleven organizations in total, from academia, industry, and regulatory agencies, participate in ARICTT. Based on multi-stakeholder collaboration from academia, industry, and government/regulatory bodies, we collected and prioritized current topics in clinical trials based on an internal survey. We established a three-year roadmap with axes that were termed trend, goal, structure, theme, topic, and method. In addition, we planned the development of recommendations based on real-world cases with feasibility studies. We developed appropriate organizational structure to fulfill the roadmap of ARICTT. The selected topics were decentralized clinical trials during the first year, followed by the three topics that were awarded the highest priority according to the internal survey: advances in the informed consent process, supporting sites using digital technology, and an effective recruitment strategy. We developed a case-based recommendation paper presenting an overview of the regulatory landscape and practical considerations with explanatory cases. We also designed and conducted fully decentralized trials to evaluate considerations in real-world settings for the selected topics. Overall engagement and communication were supported by the online platform and annual symposiums. In conclusion, we established a multi-stakeholder, public-private partnership-based organization to accelerate the transformation of clinical trials.

Synergistic toxicity with copper contributes to NAT2-associated isoniazid toxicity

Anti-tuberculosis (AT) medications, including isoniazid (INH), can cause drug-induced liver injury (DILI), but the underlying mechanism remains unclear. In this study, we aimed to identify genetic factors that may increase the susceptibility of individuals to AT-DILI and to examine genetic interactions that may lead to isoniazid (INH)-induced hepatotoxicity. We performed a targeted sequencing analysis of 380 pharmacogenes in a discovery cohort of 112 patients (35 AT-DILI patients and 77 controls) receiving AT treatment for active tuberculosis. Pharmacogenome-wide association analysis was also conducted using 1048 population controls (Korea1K). NAT2 and ATP7B genotypes were analyzed in a replication cohort of 165 patients (37 AT-DILI patients and 128 controls) to validate the effects of both risk genotypes. NAT2 ultraslow acetylators (UAs) were found to have a greater risk of AT-DILI than other genotypes (odds ratio [OR] 5.6 [95% confidence interval; 2.5-13.2], P = 7.2 × 10-6). The presence of ATP7B gene 832R/R homozygosity (rs1061472) was found to co-occur with NAT2 UA in AT-DILI patients (P = 0.017) and to amplify the risk in NAT2 UA (OR 32.5 [4.5-1423], P = 7.5 × 10-6). In vitro experiments using human liver-derived cell lines (HepG2 and SNU387 cells) revealed toxic synergism between INH and Cu, which were strongly augmented in cells with defective NAT2 and ATP7B activity, leading to increased mitochondrial reactive oxygen species generation, mitochondrial dysfunction, DNA damage, and apoptosis. These findings link the co-occurrence of ATP7B and NAT2 genotypes to the risk of INH-induced hepatotoxicity, providing novel mechanistic insight into individual AT-DILI susceptibility. Yoon et al. showed that individuals who carry NAT2 UAs and ATP7B 832R/R genotypes are at increased risk of developing isoniazid hepatotoxicity, primarily due to the increased synergistic toxicity between isoniazid and copper, which exacerbates mitochondrial dysfunction-related apoptosis.

Effects of meal type on the bioavailability of vutiglabridin, a novel anti-obesity agent, in healthy subjects

Vutiglabridin, which affects the pharmacokinetics (PKs) of food, is currently under clinical development for the treatment of obesity. This study aimed to evaluate the effects of low- and high-fat meals on PKs of vutiglabridin in healthy male subjects. A randomized, open-label, single-dose, three-period, six-sequence crossover study was conducted. The subjects received a single oral dose of vutiglabridin 480 mg in a fasted state, 30 min after the intake of a low-fat meal (total 500-600 kcal, fat content 100-125 kcal) and high-fat meal (total 800-1000 kcal, fat content 500-600 kcal), with a 21-day washout period. Geometric mean ratios (GMRs) and 90% confidence intervals (CIs) for maximum plasma concentration (Cmax ) and area under the plasma concentration-time curve to the last measurable timepoint (AUClast ) were calculated. After intake of low- and high-fat meals, systemic exposure to vutiglabridin was increased, and the time to reach Cmax (Tmax ) was delayed compared to that in the fasted state. The GMRs (90% CIs) of low-fat meal to fasted state for Cmax and AUClast were 2.14 (1.76-2.60) and 2.15 (1.92-2.42), respectively, and those of high-fat meal to fasted state were 3.07 (2.53-3.72) and 3.00 (2.67-3.37), respectively. The median Tmax was delayed by 1.5 h in both fed states compared with that in the fasted state. The study drug was well-tolerated after administration in both the fed and fasted states. Food ingestion substantially increased the extent of oral vutiglabridin absorption in healthy subjects, and this enhancement increased with the fat content of the meal.

Pharmacokinetic Comparison Between a Fixed-Dose Combination of Atorvastatin/Omega-3-Acid Ethyl Esters and the Corresponding Loose Combination in Healthy Korean Male Subjects

Purpose

Statins are widely used in combination with omega-3 fatty acids for the treatment of patients with dyslipidemia. The aim of this study was to compare the pharmacokinetic (PK) profiles of atorvastatin and omega-3-acid ethyl esters between fixed-dose combination (FDC) and loose combination in healthy subjects.

Methods

A randomized, open-label, single-dose, 2-sequence, 2-treatment, 4-period replicated crossover study was performed. Subjects were randomly assigned to one of the 2 sequences and alternately received four FDC soft capsules of atorvastatin/omega-3-acid ethyl esters (10/1000 mg) or a loose combination of atorvastatin tablets (10 mg × 4) and omega-3-acid ethyl ester soft capsules (1000 mg× 4) for four periods, each period accompanied by a high-fat meal. Serial blood samples were collected for PK analysis of atorvastatin, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). PK parameters were calculated by a non-compartmental analysis. The geometric mean ratio (GMR) and its 90% confidence interval (CI) of the FDC to the loose combination were calculated to compare PK parameters.

Results

A total of 43 subjects completed the study as planned. The GMR (90% CI) of FDC to loose combination for maximum concentration (Cmax) and area under the time-concentration curve from zero to the last measurable point (AUClast) were 1.0931 (1.0054-1.1883) and 0.9885 (0.9588-1.0192) for atorvastatin, 0.9607 (0.9068-1.0178) and 0.9770 (0.9239-1.0331) for EPA, and 0.9961 (0.9127-1.0871) and 0.9634 (0.8830-1.0512) for DHA, respectively. The intra-subject variability for Cmax and AUClast of DHA was 30.8% and 37.5%, respectively, showing high variability. Both the FDC and the loose combination were safe and well tolerated.

Conclusion

The FDC of atorvastatin and omega-3-acid ethyl esters showed comparable PK characteristics to the corresponding loose combination, offering a convenient therapeutic option for the treatment of dyslipidemia.

Pharmacogenetic Analysis of an 8-Year Old Girl with Reye Syndrome Associated with Use of Naproxen

BACKGROUND Reye syndrome is a rare, yet potentially life-threatening disease characterized by acute encephalopathy and hepatic failure. This report presents the case of an 8-year-old girl with Reye syndrome and seizures after the use of naproxen. CASE REPORT An 8-year-old girl experienced a 3-day episode of fever and abdominal pain. After receiving naproxen (375 mg twice daily) starting from day -3, she exhibited hypotension, tonic seizure, and loss of consciousness (day 1). Physical examination and laboratory test results revealed acute kidney injury, metabolic acidosis, and elevated levels of lactate dehydrogenase (LDH), liver enzymes, and ferritin. On day 2, the maximum values of aspartate aminotransferase, alanine aminotransferase, LDH, creatinine, and ferritin were 955 U/L, 132 U/L, 8040 U/L, 2 mg/dL, and >40000 ug/L, respectively. She was given supportive care and recovered after 11 days (day 12), with normalization of kidney function and metabolic abnormalities. To identify possible genetic polymorphisms associated with the patient's symptoms, genotypes were tested using a drug metabolizing enzymes and transporters (DMET) gene chip. Among genes involved in the metabolism of naproxen, UGT1A6 (*1/*2) and UGT2B7 (*1/*2) resulted in possibly decreased function. Other results which may have had clinical significance included homozygote results for NAT2*6/*6 (rs1799930). CONCLUSIONS A rare case of Reye syndrome after administration of naproxen was presented in this case. A DMET gene chip was used to screen for possible genetic polymorphisms associated with Reye syndrome, but the result was inconclusive.

Topiramate dosage optimization for effective antiseizure management via population pharmacokinetic modeling

OBJECTIVE

Despite the suggested topiramate serum level of 5-20 mg/L, numerous institutions have observed substantial drug response at lower levels. We aim to investigate the correlation between topiramate serum levels, drug responsiveness, and adverse events to establish a more accurate and tailored therapeutic range.

METHODS

We retrospectively analyzed clinical data collected between January 2017 and January 2022 at Seoul National University Hospital. Drug responses to topiramate were categorized as "insufficient" or "sufficient" by reduction in seizure frequency ≥ 50%. A population pharmacokinetic model estimated serum levels from spot measurements. ROC curve analysis determined the optimal cutoff values.

RESULTS

A total of 389 epilepsy patients were reviewed having a mean dose of 178.4 ± 117.9 mg/day and the serum level, 3.9 ± 2.8 mg/L. Only 5.6% samples exhibited insufficient response, with a mean serum level of 3.6 ± 2.5 mg/L while 94.4% demonstrated sufficient response, with a mean 4.0 ± 2.8 mg/L, having no statistical significance. Among the 69 reported adverse events, logistic regression analysis identified a significant association between ataxia and serum concentration (p = 0.04), with an optimal cutoff value of 6.5 mg/L.

INTERPRETATION

This study proposed an optimal therapeutic concentration for topiramate based on patients' responsiveness to the drug and the incidence of adverse effects. We recommended serum levels below 6.5 mg/L to mitigate the risk of ataxia-related side effects while dose elevation was found unnecessary for suboptimal responders, as the drug's effectiveness plateaus at minimal doses.

Effects of food and ethnicity on the pharmacokinetics of venadaparib, a next-generation PARP inhibitor, in healthy Korean, Caucasian, and Chinese male subjects

AIM

Venadaparib is a next-generation poly(ADP-ribose) polymerase inhibitor under development for treating gastric cancer. This study aimed to evaluate the effects of food and ethnicity on the pharmacokinetics (PKs) and safety of venadaparib after a single oral administration in healthy Korean, Caucasian, and Chinese male subjects.

METHODS

In this randomized, open-label, single-dose, two-sequence, two-period, and crossover study, Korean and Caucasian subjects received venadaparib 80 mg in each period (fasted or fed state) with a seven-day washout. In an open-label, single-dose study, Chinese subjects received venadaparib 80 mg only in the fasted state. Serial blood samples were collected up to 72 h post-dosing.

RESULTS

Twelve subjects from each ethnic group completed the study. The geometric mean ratios (90% confidence intervals) of the maximum plasma concentration (Cmax) and area under the plasma concentration-time curve from time zero to the last measurable time point (AUClast) of venadaparib for the fed to fasted state were 0.82 (0.7457-0.9094) and 1.02 (0.9088-1.1339) in Koreans, and 0.77 (0.6871-0.8609) and 0.96 (0.9017-1.0186) in Caucasians, respectively. No statistically significant differences were observed in Cmax (P-value = 0.45) or AUClast (P-value = 0.30) among the three ethnic groups. A single venadaparib dose was well-tolerated.

CONCLUSION

The overall systemic exposure of venadaparib was not affected by the high-fat meal, despite delayed absorption with a decreased Cmax in the fed state. The PK profiles were comparable among the Korean, Caucasian, and Chinese subjects. A single venadaparib 80 mg dose was safe and well-tolerated in both fasted and fed states.

Adaptive design clinical trials: current status by disease and trial phase in various perspectives

An adaptive design is a clinical trial design that allows for modification of a structured plan in a clinical trial based on data accumulated during pre-planned interim analyses. This flexible approach to clinical trial design improves the success rate of clinical trials while reducing time, cost, and sample size compared to conventional methods. The purpose of this study is to identify the current status of adaptive design and present key considerations for planning an appropriate adaptive design based on specific circumstances. We searched for clinical trials conducted between January 2006 to July 2021 in the Clinical Trials Registry (ClinicalTrials.gov) using keywords specified in the Food and Drug Administration Adaptive Design Clinical Trial Guidelines. In order to analyze the adaptive designs used in selected cases, we classified the results according to the phase of the clinical trial, type of indication, and the specific adaptation method employed. A total of 267 clinical trials were identified on ClinicalTrials.gov. Among them, 236 clinical trials actually applied adaptive designs and were classified according to phase, indication types, and adaptation methods. Adaptive designs were most frequently used in phase 2 clinical trials and oncology research. The most commonly used adaptation method was the adaptive treatment selection design. In the case of coronavirus disease 2019, the most frequently used designs were adaptive platform design and seamless design. Through this study, we expect to provide valuable insights and considerations for the implementation of adaptive design clinical trials in different diseases and stages.

Feasibility study for a fully decentralized clinical trial in participants with functional constipation symptoms

Decentralized clinical trials (DCTs) leverage digital technologies to reduce dependency on study sites and intermediaries. DCT should be balanced with accessibility and data reliability while meeting regulatory requirements. Here, we conducted a pilot study for functional constipation symptoms to investigate the feasibility of DCT. The study was an open, fully remote, randomized clinical trial in participants who had functional constipation symptoms. Electronic consent was obtained remotely, and study volunteers were screened through web-based questionnaires. Subjects were randomized to either receive Lactobacillus and vitamin C supplements or vitamin C alone in a 1:1 ratio, which were delivered directly to subjects. Subjects kept track of bowel diaries daily during the 1-week baseline and 2-week treatment period using mobile applications. Bowel symptoms and the validity of the records were descriptively evaluated. A total of 30 subjects were randomized and completed the study. A total of 26.7% of subjects resided outside of the metropolitan area. Two-week Lactobacillus treatments increased the number of defecations (+0.80 vs. +0.46 times per week) and decreased the defecation time (-3.94 h vs. -1.62 h) compared to the comparator group. Overall, 67.1% of bowel diary records were completed in accordance with the schedule whereas 32.9% were not. Implementation of DCTs can facilitate geographic accessibility but should be guaranteed for data reliability. Prompt detection of errors and response using objective metrics would be required.

Semimechanistic pharmacokinetic-pharmacodynamic model of tripegfilgrastim for pediatric patients after chemotherapy

Tripegfilgrastim is a long-acting granulocyte colony-stimulating factor (G-CSF) that has been used to prevent chemotherapy-induced neutropenia in adults. This study aimed to establish a pharmacokinetic (PK)-pharmacodynamic (PD) model to explore the impact of chemotherapy and tripegfilgrastim on absolute neutrophil counts (ANCs) and to further propose a fixed-dose regimen in pediatric patients. Because neutrophils affect the clearance of tripegfilgrastim, the semimechanistic PK-PD model was developed simultaneously by using data from 40 healthy adults and 27 pediatric patients with solid tumors. Tripegfilgrastim PK and ANC dynamics were described with a pharmacodynamics-mediated drug disposition model assuming quasi-equilibrium with five transit compartments mimicking neutrophil granulopoiesis. The effect of chemotherapy on neutrophils was included by stimulating the elimination of the G-CSF receptor at the mitotic cells. Healthy adult and pediatric patients showed significantly different value for dissociation constant of the tripegfilgrastim-G-CSF receptor complex (Kd ) and apparent volume of distribution (Vd /F). Patients treated with chemotherapy had a higher Vd /F and 62% lower Kd than healthy adults. As the age increased, the absorption rate of tripegfilgrastim was decreased. Body weight affected the G-CSF receptor-mediated internalization of tripegfilgrastim, and the baseline ANC value impacted the production rate of G-CSF receptors. Simulations from the developed model suggested that 1.5, 2.5, 4, and 6 mg single subcutaneous tripegfilgrastim doses for the respective weight groups of 10-20, 21-30, 31-44, and more than 45 kg significantly reduced the duration of Grade 4 neutropenia similar to tripegfilgrastim weight-based treatment with 100 μg/kg.

Comparison of the Pharmacokinetics, Safety, and Tolerability of Two Empagliflozin Formulations in Healthy Korean Subjects

Purpose

Empagliflozin is a sodium-glucose cotransporter 2 inhibitor that is commonly used for the treatment of type 2 diabetes mellitus. As cocrystal formulation can improve the chemical properties of drugs, CKD-370 was newly developed as a cocrystal formulation of empagliflozin with solvate L-proline. This study aimed to compare the pharmacokinetics, safety, and tolerability of these two empagliflozin formulations in healthy Korean subjects.

Methods

A randomized, open-label, two-sequence, two-period crossover study was conducted on healthy Korean participants. The subjects received a single oral 25 mg dose of either test (CKD-370) or reference treatment (Jardiance^®) tablet at each period. Plasma empagliflozin concentrations were determined using liquid chromatography with tandem mass spectrometry. Pharmacokinetic (PK) parameters were analyzed using non-compartmental methods. The primary PK parameters included the maximum concentration (C_max) and the area under the concentration-time curve from 0 to last (AUC_last). The safety of both formulations was monitored and evaluated.

Results

A total of 28 healthy Korean adult subjects were randomized, and 27 subjects were included in the PK analysis. The mean ± standard deviation values of the primary PK parameters, C_max and AUC_last after administration of the test treatment, were 442.02 ± 103.37 μg/L and 3131.08 ± 529.30 μg·h/L, respectively, and those after administration of the reference treatment were 436.29 ± 118.74 μg/L and 3006.88 ± 514.21 μg·h/L, respectively. The geometric mean ratio and its 90% confidence interval of test to reference treatment for C_max and AUC_last were 1.0221 (0.9527-1.0967) and 1.0411 (1.0153-1.0677), respectively, which were within the commonly accepted bioequivalence criteria of 0.80 to 1.25. Both treatments were well-tolerated.

Conclusion

The two formulations of empagliflozin showed similar PK characteristics and were generally well tolerated in healthy subjects.

Safety, tolerability, pharmacokinetic/pharmacodynamic characteristics of bersiporocin, a novel prolyl-tRNA synthetase inhibitor, in healthy subjects

Bersiporocin, a novel first-in-class prolyl-tRNA synthetase (PRS) inhibitor currently under clinical development, was shown to exert an antifibrotic effect through the downregulation of collagen synthesis in various pulmonary fibrosis models. The aim of this first-in-human, randomized, double-blind, placebo-controlled, single- and multiple-dose, dose-escalation study was to evaluate the safety, tolerability, pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of bersiporocin in healthy adults. A total of 40 and 32 subjects were included in a single- (SAD) and multiple-ascending dose (MAD) study, respectively. No severe or serious adverse events were observed after a single oral dose up to 600 mg and multiple oral doses up to 200 mg twice daily for 14 days. The most common treatment-emergent adverse events were gastrointestinal adverse events. To improve the tolerability, initial bersiporocin solution was changed to the enteric-coated formulation. Afterward, the enteric-coated tablet was used in the last cohort of SAD and in the MAD study. Bersiporocin showed dose-proportional PK characteristics after a single dose up to 600 mg and multiple doses up to 200 mg. Upon reviewing the safety and PK data, the final SAD cohort (800 mg enteric-coated tablet) was canceled by the Safety Review Committee. The levels of pro-peptide of type 3 procollagen were lower after treatment with bersiporocin than after the placebo in the MAD study, whereas no significant change was observed in other idiopathic pulmonary fibrosis (IPF) biomarkers. In conclusion, the safety, PK, and PD profile of bersiporocin supported its further investigation in patients with IPF.

Continuous versus Intermittent Infusion of Human Antithrombin III Concentrate in the Immediate Postoperative Period after Liver Transplantation

Antithrombin-III (AT-III) concentrates have been used in the immediate postoperative period after liver transplantation to prevent critical thrombosis. We aimed to investigate more appropriate method for AT-III concentrate administration to maintain plasma AT-III activity level within targeted range. In this randomized controlled trial, 130 adult patients undergoing living-donor liver transplantation were randomized to either intermittent group or continuous group. In intermittent group, 500 international units (IU) of AT-III concentrate were administered after liver transplantation and repeated every 6 hours for 72 hours. In continuous group, 3000 IU of AT-III was continuously infused for 71 hours after a loading dose of 2000 IU over 1 hour. Plasma AT-III activity level was measured at 12, 24, 48, 72, and 84 hours from the first AT-III administration. The primary outcome was the target (80-120%) attainment rate at 72 hours. Target attainment rates at other time points and associated complications were collected as secondary outcomes. A total of 107 patients were included in the analysis. The target attainment rates at 72 hours post-dose were 30% and 62% in intermittent group and continuous group, respectively. (p=0.003) Compared to intermittent group, patients in continuous group reached the target level more rapidly (12 vs. 24 hours, median time, p<0.001) and was more likely to remain in the target range until 84 hours. For maintaining the target plasma AT-III activity level after living-donor liver transplantation, continuous infusion of AT-III seemed to be more appropriate compared to the conventional intermittent infusion regimen.

Randomised clinical trial: Safety, tolerability, pharmacodynamics and pharmacokinetics of zastaprazan (JP-1366), a novel potassium-competitive acid blocker, in healthy subjects

BACKGROUND

Zastaprazan (JP-1366) is a novel potassium-competitive acid blocker with favourable preclinical safety and efficacy profile being developed for the treatment of acid-related diseases.

AIMS

To investigate the safety, tolerability, pharmacodynamics and pharmacokinetics of zastaprazan.

METHODS

A randomised, open-label, placebo- and active-controlled, single and multiple ascending dose clinical trial was conducted in healthy Korean male subjects. Intragatric pH and serum gastrin were measured to assess the pharmacodynamics, while serial blood and urine samples were collected to assess the pharmacokinetics. Pharmacogenomic evaluation was conducted to explore genetic variants, which can affect the pharmacodynamics and pharmacokinetics. Safety and tolerability including hepatotoxicity were evaluated.

RESULTS

Suppression of gastric acid secretion increased as the dose of zastaprazan increased. The percentage of time that gastric pH was over 4 (%Time pH >4) with zastaprazan 20 mg (85.19%) and 40 mg (91.84%) were similar to or greater than that with esomeprazole 40 mg (72.06%). Zastaprazan was rapidly absorbed within 2 h and eliminated with a half-life of 6-10 h. Pharmacogenomic analysis found no genetic variant of drug metabolising enzymes including CYP2C19 or drug transporters associated with the exposure of zastaprazan. Zastaprazan was well tolerated with no clinically significant changes in safety and tolerability assessments.

CONCLUSIONS

Zastaprazan was safe and well tolerated after a single oral dose up to 60 mg and multiple oral doses up to 40 mg. It also showed rapid, potent suppression of gastric acid secretion. Pharmacodynamic and pharmacokinetic profile of zastaprazan was suitable for treatment of patients with acid-related diseases.

Pharmacokinetics, safety and tolerability of valbenazine in Korean CYP2D6 normal and intermediate metabolizers

Valbenazine is a selective vesicular monoamine transporter 2 (VMAT2) inhibitor approved for tardive dyskinesia treatment by the US Food and Drug Administration; its major active metabolite (NBI-98782) is a 45-fold more potent inhibitor of VMAT2 than the parent drug. This study aimed to evaluate the pharmacokinetics (PKs), safety, and tolerability and the effect of cytochrome P450 2D6 (CYP2D6) genotypes to the PKs after the administration of valbenazine in Korean participants. A randomized, double-blind, placebo-controlled, single- and multiple-dose study was conducted in healthy Korean male participants. The single-dose study was conducted for both 40 and 80 mg valbenazine and the multiple dose study was conducted for 40 mg. After a 1-week washout, the 40 mg dose group participants received valbenazine 40 mg or placebo once daily for 8 days. Serial blood samples were collected up to 96 h postdose for PK analysis. The CYP2D6 genotypes of the participants were retrospectively analyzed. A total of 50 participants were randomized, and 43 and 20 participants completed the single- and multiple-dose phases of the study, respectively. After single doses, the PK characteristics of valbenazine and its metabolites were similar between the 40 and 80 mg dose groups. After multiple doses, the mean accumulation ratios of valbenazine and NBI-98782 were ~1.6 and 2.4, respectively. Plasma concentrations of valbenazine and NBI-98782 were similar between CYP2D6 normal and intermediate metabolizers. Valbenazine was well-tolerated in healthy Koreans, and its PK characteristics were similar to results previously reported in Americans.

Effect of hemodialysis on the pharmacokinetics and pharmacodynamics of evogliptin

AIM

To investigate the possible effect of hemodialysis (HD) on the pharmacokinetics (PKs) and pharmacodynamics (PDs) of evogliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor.

METHODS

A single-dose, open-label, parallel-group study of eight end-stage renal disease (ESRD) patients and eight matched healthy subjects was conducted. ESRD patients received a single oral dose of evogliptin 5 mg after and before HD with a 2-week washout between each dose, and healthy subjects received a single oral dose of evogliptin 5 mg. Serial blood, dialysate and urine samples were collected to assess the PK and PD profiles of evogliptin. To compare PK parameters before and after HD, geometric mean ratios (GMRs) and 90% confidence intervals (CIs) were calculated.

RESULTS

The GMRs and its 90% CIs for the maximum concentration (C_max ) and area under the concentration-time curve from time 0 to the last measurable timepoint (AUC_last ) of evogliptin when administered before HD compared to after HD were 0.7293 (0.6171-0.8620) and 0.9480 (0.8162-1.1010), respectively. The maximum DPP-4 inhibitory effect (E_max ), area under the DPP-4 inhibitory effect-time curve (AUEC_last ), and time duration of more than 80% DPP-4 inhibition (Fi80) were comparable when evogliptin was administered before and after HD. Compared to healthy subjects, the mean AUC_last of evogliptin was approximately 1.4-fold greater in ESRD patients, but the difference is unlikely to affect the safety and efficacy of evogliptin.

CONCLUSION

The effect of HD on the PKs and PDs of evogliptin was not clinically significant; therefore, dose adjustment according to HD status is not necessary. This article is protected by copyright. All rights reserved.

Pharmacodynamic and Pharmacokinetic Drug Interactions between Fexuprazan, a Novel Potassium-Competitive Inhibitor, and Aspirin, in Healthy Subjects

Acid-reducing agents are commonly used for the prevention of aspirin-induced gastrointestinal complications such as peptic ulcers. As a novel potassium-competitive acid blocker, fexuprazan is expected to prevent aspirin-induced gastrointestinal complications. This randomized, open-label study aimed to evaluate the pharmacodynamic and pharmacokinetic interactions between aspirin and fexuprazan in healthy Koreans. Subjects randomized to the aspirin group received 500 mg aspirin in combination with 80 mg fexuprazan. For the fexuprazan group, fexuprazan 80 mg was administered alone and then in combination with aspirin 500 mg. Platelet aggregation inhibited by aspirin and the pharmacokinetic parameters of aspirin and fexuprazan were compared between monotherapy and combination therapy. A total of 22 subjects completed the study. The platelet aggregation-inhibitory activity and systemic exposure to aspirin were not significantly affected by fexuprazan coadministration. The systemic exposure of fexuprazan was decreased up to 20% by aspirin coadministration, which was not regarded as clinically meaningful considering the previously reported exposure-response relationship. In conclusion, there were no clinically relevant pharmacodynamic or pharmacokinetic interactions between aspirin and fexuprazan. This finding suggests the potential of fexuprazan for the prevention of aspirin-induced gastrointestinal complications, serving as a baseline for optimizing its therapeutic application with aspirin.

Conventional reversal of rocuronium-induced neuromuscular blockade by sugammadex in Korean children: pharmacokinetics, efficacy, and safety analyses

Background: Sugammadex is known to reverse neuromuscular blockade induced by non-depolarizing agents. In children, the recommended dose for reversal of moderate neuromuscular blockade is 2 mg/kg. We investigated the pharmacokinetics and pharmacodynamics of sugammadex in Korean children. Methods: Children (2-17 years of age) undergoing brain or spine surgery were enrolled and randomly assigned to control (neostigmine) and 2, 4, or 8 mg/kg sugammadex groups. Following induction of anesthesia and monitoring of the response to train-of-four stimulation, 1 mg/kg rocuronium was intravenously administered. Upon reappearance of the second twitch to train-of-four stimulation, the study drug was administered according to group allocation. The plasma concentrations of rocuronium and sugammadex were serially measured at nine predefined time points following study drug administration. To determine efficacy, we measured the time elapsed from drug administration to recovery of T₄/T₁ ≥ 0.9. For pharmacokinetics, non-compartmental analysis was performed and we monitored adverse event occurrence from the time of study drug administration until 24 h post-surgery. Results: Among the 29 enrolled participants, the sugammadex (2 mg/kg) and control groups showed recovery times [median (interquartile range)] of 1.3 (1.0-1.9) and 7.7 (5.3-21.0) min, respectively (p = 0.002). There were no significant differences in recovery time among the participants in sugammadex groups. The pharmacokinetics of sugammadex were comparable to those of literature findings. Although two hypotensive events related to sugammadex were observed, no intervention was necessary. Conclusion: The findings of this pharmacokinetic analysis and efficacy study of sugammadex in Korean children indicated that sugammadex (2 mg/kg) may be safely administered for reversing moderate neuromuscular blockade. Some differences in pharmacokinetics of sugammadex were observed according to age. Clinical Trial Registration: http://clinicaltrials.gov (NCT04347486).

Pharmacokinetic evaluation of radiolabeled intraocular anti-CLEC14a antibody in preclinical animal species and application in humans

Anti-angiogenic antibodies are widely used in the treatment of neovascular macular degeneration. Human antibody targeting C-type lectin domain family 14 member A (CLEC14a) is potential therapeutic agents owing to its antiangiogenic activity. In the present study, we aimed to predict the human intraocular pharmacokinetic (PK) properties of an anti-CLEC14a antibody. I-125 labeled aflibercept and anti-CLEC14a antibody were intravitreally injected into mice, rats, and rabbits. Single photon emission computed tomography/computed tomography imaging was performed, and the intraocular radioactivity concentration (%ID/ml) was obtained. The PK parameters in those three animal species were obtained by compartmental analysis. The PK parameters in humans were estimated by allometric scaling of the animal PK parameters with consideration of the hydrodynamic radius of the antibody. The mean half-life values of intraocular I-125-labeled aflibercept in mice, rats, and rabbits were 1.13 days, 1.25 days, and 4.91 days, respectively, by analysis with a one-compartment model. The predicted human half-life of intraocular aflibercept was 5.75 days based on vitreal volume by allometric scaling. The half-life values of intraocular I-125-labeled anti-CLEC14a in mice, rats and rabbits were 1.05 days, 1.84 days, and 6.37 days, respectively, by analysis with a one-compartment model. The predicted human half-life of intraocular anti-CLEC14a was 10.29 days based on vitreal volume. According to the hydrodynamic volume of the anti-CLEC14a, the predicted human half-life of intraocular anti-CLEC14a was 9.81 days. The PK characteristics of the intraocular anti-CLEC14a antibody were evaluated noninvasively in animals using I-125 labeling, and the intraocular PK characteristics in humans were predicted using these animal data. This methodology can be applied for the development of new antiangiogenic antibodies to treat macular degeneration.

A database of 5305 healthy Korean individuals reveals genetic and clinical implications for an East Asian population

Despite substantial advances in disease genetics, studies to date have largely focused on individuals of European descent. This limits further discoveries of novel functional genetic variants in other ethnic groups. To alleviate the paucity of East Asian population genome resources, we established the Korean Variant Archive 2 (KOVA 2), which is composed of 1896 whole-genome sequences and 3409 whole-exome sequences from healthy individuals of Korean ethnicity. This is the largest genome database from the ethnic Korean population to date, surpassing the 1909 Korean individuals deposited in gnomAD. The variants in KOVA 2 displayed all the known genetic features of those from previous genome databases, and we compiled data from Korean-specific runs of homozygosity, positively selected intervals, and structural variants. In doing so, we found loci, such as the loci of ADH1A/1B and UHRF1BP1, that are strongly selected in the Korean population relative to other East Asian populations. Our analysis of allele ages revealed a correlation between variant functionality and evolutionary age. The data can be browsed and downloaded from a public website ( https://www.kobic.re.kr/kova/ ). We anticipate that KOVA 2 will serve as a valuable resource for genetic studies involving East Asian populations.

Safety, tolerability, pharmacokinetic, and pharmacodynamic characteristics of vutiglabridin: A first-in-class, first-in-human study

This study aimed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of vutiglabridin, a potential anti-obesity treatment under development, for the first time in humans. A randomized, placebo-controlled, single- and multiple-ascending dose study (SAD and MAD, respectively) was performed in healthy Koreans and Whites. Subjects randomly received a single oral dose of 30-720 mg vutiglabridin or placebo at a ratio of 8:2 in the SAD study or 240-480 mg vutiglabridin or placebo once daily for 14 days in the MAD study. Food effect was also evaluated in 240 mg single dose group. Pharmacokinetics were evaluated through plasma concentrations, and pharmacodynamic biomarkers related to obesity or inflammation were analyzed. Safety and tolerability were assessed throughout the study. Single and multiple doses of vutiglabridin were generally well-tolerated. The pharmacokinetic parameters show less than dose-proportionality increase, and plasma concentrations increased more than two-fold after multiple administrations. The mean half-life of Koreans and Whites in the MAD study was 110 and 73 h, respectively. The systemic exposure of vutiglabridin was significantly increased when taken with a high-fat meal, and the systemic exposure was lower in Whites than in Koreans. Vutiglabridin was well-tolerated in healthy Koreans and Whites. The plasma concentration increased less than the dose-proportionality manner. These results justify further investigation of vutiglabridin in patients with obesity.

Reversal of rocuronium-induced intense neuromuscular blockade by sugammadex in Korean children: A pharmacokinetic and pharmacodynamic analysis

Sugammadex, a selective antagonist of steroidal non-depolarizing neuromuscular blocking agents, has been used in children in limited circumstances. However, neither pharmacokinetics (PKs) nor recovery profile of sugammadex for intense neuromuscular blockade reversal in children have been reported. This prospective study aimed to obtain a PK model of sugammadex and evaluate its efficacy and safety for intense neuromuscular blockade reversal in children. Forty children (age, 2-17 years) who underwent surgery that required early neuromuscular blockade reversal were enrolled. After neuromuscular blockade with 1 mg∙kg^-1 of rocuronium, sugammadex (2, 4, and 8 mg∙kg^-1 ) or a conventional dose of neostigmine (0.03 mg∙kg^-1 ) was administered randomly after confirmation of zero post-tetanic count. The plasma concentrations of rocuronium and sugammadex were measured 2 min after rocuronium injection; immediately before, 2, 5, 15, 60, 120, 240, and 480 min after the study drug injection. Response to train-of-four stimulation was continuously recorded. Noncompartmental analysis and population PK modeling were performed. For pharmacodynamics, the recovery profile was measured. Three-compartment PK model was established for sugammadex. The median (interquartile range [IQR]) time from injection of 8 mg∙kg^-1 of sugammadex to recovery of T₄ /T₁ greater than or equal to 0.9 at train-of-four stimulation was 1.1 (IQR: 0.88-1.8) min. No adverse events related to sugammadex were observed. We present a PK analysis of sugammadex for rocuronium-induced intense neuromuscular blockade reversal in children with its recovery profile. The time to recover T₄ /T₁ greater than or equal to 0.9 at train-of-four stimulation with 8 mg∙kg^-1 of sugammadex was less than 3 min and comparable to that in adults.

The pharmacokinetic, safety, and tolerability profiles of eslicarbazepine acetate are comparable between Korean and White subjects

Eslicarbazepine acetate (ESL) is a prodrug antiseizure medication for the treatment of focal seizures. ESL shows a well-established pharmacokinetic (PK)-pharmacodynamic relationship and has similar extrinsic epilepsy-related factors across ethnicities. This study evaluated and compared ESL safety, tolerability, and PK characteristics between Korean and White subjects. A randomized, double-blind, placebo-controlled, single- and multiple-dose escalation study was conducted in healthy Korean and White adults. Participants randomly received a single dose and multiple oral doses of ESL (400-1600 mg) or placebo once daily for 11 days at a ratio of 8:2. Serial blood samples were collected to determine the plasma concentration of ESL and its metabolites (eslicarbazepine, [R-licarbazepine and oxcarbazepine). Safety and tolerability were assessed throughout the study. A total of 29 Korean and 20 White subjects completed the study. The PK profiles of the metabolites of ESL were similar between Korean and White subjects. The geometric mean ratio (90% confidence interval) of Korean to White subjects for the area under the concentration-time curve within a dosing interval of eslicarbazepine was 1.06 (0.97-1.17) and 0.96 (0.87-1.06) after multiple oral doses of 400 and 1600 mg ESL, respectively. Other PK parameters were also similar between the two ethnic groups. ESL was well-tolerated in healthy Korean and White subjects, and its PK characteristics were similar between the two ethnic groups. The results of this study support to use the same dosage regimen of ESL in both White and Korean patients with seizures.

Dose-dependent reduction of lymphocyte count and heart rate after multiple administration of LC51-0255, a novel sphingosine-1-phosphate receptor 1 modulator, in healthy subjects

Aim: Sphingosine-1-phosphate receptor mediates the egress of lymphocytes from lymphoid organs, and its inhibition results in a decreased number of circulating lymphocytes. The aim of the current study was to investigate the safety and pharmacodynamic and pharmacokinetic characteristics of a novel sphingosine-1-phosphate receptor modulator, LC51-0255.

Methods: A phase 1 randomized, double-blind, placebo-controlled, multiple dosing, dose-escalation study was conducted on healthy Korean male subjects.

Results: After single and daily administration of LC51-0255 for 21 days, a dose-dependent decrease in lymphocyte count and heart rate was observed through 0.25–2 mg dose range of LC51-0255. The mean elimination half-life of LC51-0255 was 76–95 h. LC51-0255 was accumulated with a mean accumulation ratio of 5.17–6.64. During the study, LC51-0255 was generally well tolerated. The most common treatment-emergent adverse event was bradycardia. No clinically significant event of arrhythmia, including AV block, was observed. No clinically significant difference in blood pressure was observed between the dose groups. In other safety assessments, no clinically significant abnormalities were observed, except for bradycardia.

Conclusion: Daily administration of LC51-0255 in the range of 0.25–2 mg resulted in a dose-dependent reduction of lymphocyte counts and heart rate. LC51-0255 is generally safe and well tolerated in healthy volunteers.

Clinical Evaluation of Digital Therapeutics: Present and Future

Objectives

Digital therapeutics (DTx) are software-based therapeutic interventions based on clinical evidence. Randomized clinical trials (RCTs) are often the source of clinical evidence, similar to conventional drugs or medical devices. However, novel approaches such as the use of real-world data or digital biomarkers are also utilized. This article aimed to review how DTx products have been clinically evaluated.

Methods

DTx products approved by the US Food and Drug Administration as of 2020 were reviewed and products with sufficient published information were selected. Pivotal clinical trials were analyzed according to the elements of the Consolidated Standards of Reporting Trials (CONSORT) guideline. Case reviews were presented for other clinical evaluation strategies, considering the small number of publications.

Results

Most approved DTx products used RCTs for clinical evaluations. Similar to conventional RCTs, parallel-group designs with statistical hypothesis testing were adopted. However, DTx trials were often not blinded due to practical issues and involved various comparator groups. In addition, DTx products could be readily evaluated in home-based settings and delivered through the internet. Other evaluation approaches included retrospective analyses using insurance claims data or usage data, which enabled long-term evaluations of effectiveness. Digital biomarkers obtained from real-time and continuous log data were also used to improve the objectiveness of endpoints.

Conclusions

RCTs accounted for the majority of DTx evaluations. The designs of DTx trials were comparable to those of drug or device trials, but blinding and comparator elements were often different. Furthermore, the use of real-world data and digital biomarkers are also being tried.

Key Considerations for Phase 2 or 3 Clinical Study Design of Anti-Inflammatory Agent for COVID-19 Treatment

Purpose: Current understanding of COVID-19 disease progression suggests a major role for the “cytokine storm” as an important contributor to COVID-19 mortality. To prevent an exaggerated immune response and improve COVID-19 patient endpoints, anti-inflammatory therapeutics have been proposed as clinically useful in severe patients with COVID-19. The purpose of this study was to propose a clinical trial design for the development of anti-inflammatory agents for the treatment of COVID-19, taking into account the physiological and immunological process of COVID-19 and the treatment mechanism of anti-inflammatory agents.

Methods: We reviewed and analyzed the guidelines for the development of COVID-19 treatments and the treatment of COVID-19 by regulatory agencies and previously conducted clinical trials on anti-inflammatory drugs for COVID-19. Finally, after discussing with an advisory group, a synopsis was presented for an example protocol for a COVID-19 anti-inflammatory agent phase 2 or 3 study that considers the drug mechanism and the disease progression of COVID-19.

Results: A randomized, placebo-controlled, double-blind parallel-group design was suggested as a phase 2 or 3 trial design for developing an anti-inflammatory agent as a COVID-19 treatment. A key item of the example protocol specific to anti-inflammatory agents was the inclusion and exclusion criteria, taking into account the immunosuppressive effects of the drug, clinical time course of COVID-19 disease, and treatment guidelines for COVID-19. Time to recovery is the primary endpoint associated with clinical efficacy and is generally well accepted by many experts.

Conclusion: Through this suggested phase 2 or 3 study design of an anti-inflammatory drug for COVID-19, we provide a basis for a study design that can be utilized in clinical development by pharmaceutical companies which are developing a potential anti-inflammatory agent for COVID-19.

Population pharmacokinetic analysis of sildenafil in term and preterm infants with pulmonary arterial hypertension

Sildenafil is widely used off-label in pediatric patients with pulmonary arterial hypertension (PAH). This study was conducted to characterize the pharmacokinetics (PK) of sildenafil in term and preterm neonates with PAH, by developing a population PK model, and to suggest appropriate doses to achieve clinically effective concentrations. A population PK modelling analysis was performed using sildenafil and its metabolite N-desmethyl sildenafil (DMS) concentration data from 19 neonates with PAH, whose gestational ages ranged 24–41 weeks. They received sildenafil orally at a dose of 0.5–0.75 mg/kg, four times a day. To investigate the appropriate sildenafil dose, simulations were conducted according to body weight which was significant covariate for sildenafil clearance. A one-compartment model with first-order absorption adequately described the PKs of sildenafil and DMS. Sildenafil clearance was expected to increase rapidly with increasing body weight. In the simulation, sildenafil doses > 1 mg/kg was required to achieve and maintain target concentrations of sildenafil and to expect timely clinical effects in term and preterm infants. These results could be utilized for the safer and more effective use of sildenafil in term and preterm infants.

Dose-dependent glucosuria of DWP16001, a novel selective SGLT-2 inhibitor, in healthy subjects

AIMS

DWP16001 is a novel sodium-glucose cotransporter-2 (SGLT-2) inhibitor under development for the treatment of type 2 diabetes mellitus. This study was conducted to evaluate the pharmacokinetics (PK), pharmacodynamics (PD), and safety of DWP16001 after single and multiple doses in healthy subjects.

METHODS

A randomized, double-blind, placebo- and active-controlled, single- and multiple-dose study was conducted. Twelve subjects in each dose group received a single dose (0.2, 0.5, 1.0, 2.0, or 5.0 mg) or multiple doses (0.1, 0.3, 0.5, 1.0, or 2.0 mg once daily for 15 consecutive days) of DWP16001, dapagliflozin 10 mg, or placebo at a ratio of 8:2:2. Serial blood and interval urine samples were collected for the PK and PD analyses. The safety and tolerability of DWP16001 were also assessed.

RESULTS

A dose-dependent increase in the urinary glucose excretion (UGE) was observed after a single dose, and the steady state UGE was 50-60 g/day after multiple doses in the dose range of 0.3 - 2.0 mg. DWP16001 was rapidly absorbed with the time to peak plasma concentration of 1.0 - 3.0 hours, and it exhibited a mean elimination half-life of 13-29 h. The systemic exposure to DWP16001 increased proportionally with multiple dose administrations in the range of 0.1-2.0 mg. DWP16001 was well tolerated in all dose groups.

CONCLUSION

DWP16001 induced glucosuria in a dose-dependent manner, and systemic exposure was observed after multiple doses. DWP16001 was well tolerated in single oral doses of up to 5.0 mg and in multiple oral doses of up to 2.0 mg.

Single‐dose of LC51‐0255, a Selective S1P 1 Receptor Modulator, Showed Dose‐dependent and Reversible Reduction of Absolute Lymphocyte Count in Humans

Reducing the peripheral absolute lymphocyte count (ALC) is a promising therapeutic approach in treating autoimmune diseases. LC51‐0255 is a sphingosine‐1‐phosphate 1 receptor modulator, which is known to decrease the peripheral ALC. We aimed to assess the pharmacokinetics (PKs), pharmacodynamics (PDs), safety, and tolerability profiles of LC51‐0255 after a single oral administration in healthy subjects. A randomized, double‐blind, placebo‐controlled, dose‐escalation study was conducted in 50 healthy subjects. Each subject orally received LC51‐0255 (0.25, 0.5, 1, 2, or 4 mg) or its matching placebo in an 8:2 ratio. Blood and urine samples were collected to assess the PKs, and PDs was evaluated using peripheral ALC and 24‐h hourly heart rate data. Safety and tolerability were assessed by monitoring treatment emergent adverse events (TEAEs), vital signs, 12‐lead electrocardiogram (ECG), continuous 24‐h ECG (via Holter monitoring), clinical laboratory tests, ophthalmologic tests, pulmonary function tests, and physical examinations. A single dose of LC51‐0255 reduced ALC and heart rate in a reversible and dose‐dependent manner. Systemic exposure of LC51‐0255 increased dose‐dependently and its half‐life ranged from 72.2 to 134.0 h. ALC and the systemic exposure of LC51‐0255 seemed to be negatively correlated. LC51‐0255 was well‐tolerated up to 2 mg, and the most common TEAE was bradycardia. The results of this study suggest that LC51‐0255 can be developed into a beneficial treatment option for autoimmune disease.

Endogenous metabolic markers for predicting the activity of dihydropyrimidine dehydrogenase

Five‐fluorouracil (5‐FU) is a chemotherapeutic agent that is mainly metabolized by the rate‐limiting enzyme dihydropyrimidine dehydrogenase (DPD). The DPD enzyme activity deficiency involves a wide range of severities. Previous studies have demonstrated the effect of a DPYD single nucleotide polymorphism on 5‐FU efficacy and highlighted the importance of studying such genes for cancer treatment. Common polymorphisms of DPYD in European ancestry populations are less frequently present in Koreans. DPD is also responsible for the conversion of endogenous uracil (U) into dihydrouracil (DHU). We quantified U and DHU in plasma samples of healthy male Korean subjects, and samples were classified into two groups based on DHU/U ratio. The calculated DHU/U ratios ranged from 0.52 to 7.12, and the two groups were classified into the 10th percentile and 90th percentile for untargeted metabolomics analysis using liquid chromatography‐quantitative time‐of‐flight‐mass spectrometry. A total of 4440 compounds were detected and filtered out based on a coefficient of variation below 30%. Our results revealed that six metabolites differed significantly between the high activity group and low activity group (false discovery rate q‐value < 0.05). Uridine was significantly higher in the low DPD activity group and is a precursor of U involved in pyrimidine metabolism; therefore, we speculated that DPD deficiency can influence uridine levels in plasma. Furthermore, the cutoff values for detecting DPD deficient patients from previous studies were unsuitable for Koreans. Our metabolomics approach is the first study that reported the DHU/U ratio distribution in healthy Korean subjects and identified a new biomarker of DPD deficiency.

Comprehensive analysis of important pharmacogenes in Koreans using the DMET™ platform

Genetic polymorphisms of enzymes and transporters associated with the absorption, distribution, metabolism, and elimination (ADME) of drugs are one of the major factors that contribute to interindividual variations in drug response. In the present study, we aimed to elucidate the pharmacogenetic profiles of the Korean population using the Affymetrix Drug Metabolizing Enzyme and Transporters (DMET™) platform. A total of 1,012 whole blood samples collected from Korean subjects were genotyped using the DMET™ plus microarray. In total, 1,785 single nucleotide polymorphism (SNP) markers for 231 ADME genes were identified. The genotype and phenotype of 13 clinically important ADME genes implemented in the Clinical Pharmacogenetics Implementation Consortium guidelines were compared among different ethnic groups. Overall, the genotype frequencies of the Korean population were similar to those of the East Asian population. Several genes, notably CYP2C19 and VKORC1, showed marked differences in Koreans compared to Europeans (EURs) or Africans (AFRs). The percentage of CYP2C19 poor metabolizers was 15% in Koreans and less than 3% in EURs or AFRs. The frequencies of causative SNPs of the VKORC1 gene for the low warfarin dose phenotype were 90%, 60%, and 10% in Koreans, EURs and AFRs, respectively. Our findings can be utilized for optimal pharmacotherapy in Korean patients.

Pharmacokinetic and Pharmacodynamic Characteristics of Tripegfilgrastim, a Pegylated G-CSF, in Pediatric Patients with Solid Tumors

A long-acting granulocyte colony-stimulating factor, tripegfilgrastim, was approved in Korea for the prevention of chemotherapy-induced neutropenia in adult patients. In this study, we evaluated the pharmacokinetics, pharmacodynamics, and safety of tripegfilgrastim in pediatric patients. A phase I, open-label, single ascending-dose study was performed in pediatric patients with solid tumors or lymphoma (ClinicalTrials.gov, NCT02963389). The patients were stratified according to age groups (aged 6 to 12 or 12 to 19 years) and received a single subcutaneous dose of tripegfilgrastim 60 μg/kg or 100 μg/kg. Tripegfilgrastim was administered 24 hours after the end of the chemotherapy, and serial blood sampling and safety monitoring were conducted. Twenty-seven patients with solid tumors were enrolled in this study. Tripegfilgrastim was detectable in plasma for an extended period (terminal half-life > 40 hours), and plasma concentrations increased slightly less than dose proportionally. The mean duration of grade 4 neutropenia was reduced as the average tripegfilgrastim concentration during the initial neutrophil recovery process increased. No substantial differences in the pharmacokinetic and pharmacodynamic responses were observed between the two age groups. When stratified by body weight, weighing more than 45 kg has a higher risk of a prolonged neutropenia period when receiving the lower dose (60 μg/kg) of tripegfilgrastim. Tripegfilgrastim was generally safe and well-tolerated in the pediatric patients. These results justify further clinical investigations of tripegfilgrastim at 100 μg/kg dose in pediatric patients.

Unraveling the Genomic Architecture of the CYP3A Locus and ADME Genes for Personalized Tacrolimus Dosing

BACKGROUND

Tacrolimus (TAC) is an immunosuppressant widely prescribed following an allogenic organ transplant. Due to wide interindividual pharmacokinetic (PK) variability, optimizing TAC dosing based on genetic factors is required to minimize nephrotoxicity and acute rejections.

METHODS

We enrolled 1133 participants receiving TAC from 4 cohorts, consisting of 3 with kidney transplant recipients and 1 with healthy males from clinical trials. The effects of clinical factors were estimated to appropriately control confounding variables. A genome-wide association study, haplotype analysis, and a gene-based association test were conducted using the Korea Biobank Array or targeted sequencing for 114 pharmacogenes.

RESULTS

Genome-wide association study verified that CYP3A5*3 is the only common variant associated with TAC PK variability in Koreans. We detected several CYP3A5 and CYP3A4 rare variants that could potentially affect TAC metabolism. The haplotype structure of CYP3A5 stratified by CYP3A5*3 was a significant factor for CYP3A5 rare variant interpretation. CYP3A4 rare variant carriers among CYP3A5 intermediate metabolizers displayed higher TAC trough levels. Gene-based association tests in the 61 absorption, distribution, metabolism, and excretion genes revealed that CYP1A1 are associated with additional TAC PK variability: CYP1A1 rare variant carriers among CYP3A5 poor metabolizers showed lower TAC trough levels than the noncarrier controls.

CONCLUSIONS

Our study demonstrates that rare variant profiling of CYP3A5 and CYP3A4, combined with the haplotype structures of CYP3A locus, provide additive value for personalized TAC dosing. We also identified a novel association between CYP1A1 rare variants and TAC PK variability in the CYP3A5 nonexpressers that needs to be further investigated.

Population Pharmacokinetic Modelling and Simulation to Determine the Optimal Dose of Nanoparticulated Sorafenib to the Reference Sorafenib

Sorafenib, an oral multikinase inhibitor, exhibits a highly variable absorption profile due to enterohepatic reabsorption and poor solubility. SYO-1644 improved the solubility of sorafenib by nanoparticulation technology leading to enhanced bioavailability. To evaluate the pharmacokinetically equivalent dose of SYO-1644 to the reference Nexavar^® 200 mg, a randomized, open-label, replicated two-period study was conducted in healthy volunteers. A total of 32 subjects orally received a single dose of the following assigned treatment under a fasted state in the first period and repeated once more in the second period with a two-week washout: SYO-1644 100, 150 and 200 mg and Nexavar^® 200 mg. Pharmacokinetic (PK) samples were collected up to 168 h post-dose. The PK profile was evaluated by both non-compartmental analysis and population PK method. With the final model, 2 × 2 crossover trial scenarios with Nexavar^® 200 mg and each dose of SYO-1644 ranging from 100 to 150 mg were repeated 500 times by Monte Carlo simulation, and the proportion of bioequivalence achievement was assessed. Transit absorption compartments, followed by a one-compartment model with first-order elimination and enterohepatic reabsorption components were selected as the final model. The simulation results demonstrated that the SYO-1644 dose between 120 and 125 mg could yielded the highest proportion of bioequivalence.

Comparison of Pharmacokinetic, Pharmacodynamic and Tolerability Profiles of CKD-11101, Darbepoetin Alfa (NESP®) Biosimilar, to Those of NESP® After a Single Subcutaneous or Intravenous Administration to Healthy Subjects

Introduction

Darbepoetin alfa (NESP^® and ARANESP^®) has a sustained erythropoietic activity with a longer half-life than conventional recombinant human erythropoietin. CKD-11101 is under clinical development as a biosimilar of darbepoetin alfa. The purpose of this study was to compare the pharmacokinetic (PK), pharmacodynamic (PD), and tolerability profiles of CKD-11101 with those of reference drug in healthy subjects.

Methods

This study was performed in two parts for healthy subjects. In each period, CKD-11101 and reference, both at 60 μg, were administered via intravenous (IV) or subcutaneous (SC) route of administration.

Results

After both IV or SC dose, the geometric mean ratio (GMR) of CKD-11101 to reference drug and its 90% confidence intervals (CIs) for C_max, AUC_0-last and AUC_0-∞ were all within 0.8-1.25. No statistically significant differences were noted in the maximum baseline adjusted reticulocyte count or the area under the baseline adjusted reticulocyte count-time between the CKD-11101 and reference drug after IV or SC dose (all p-value>0.05). Both CKD-11101 and reference drug were generally well tolerated.

Discussion

After a single IV or SC dose, the CKD-11101 was well tolerated and showed comparable PK and PD characteristics with reference drug.

Pharmacokinetic comparison between a fixed-dose combination of fimasartan/amlodipine/hydrochlorothiazide 60/10/25 mg and a corresponding loose combination of fimasartan/amlodipine 60/25 mg and hydrochlorothiazide 25 mg in healthy subjects

For the treatment of hypertension, fixed-dose combinations (FDCs) of antihypertensive drugs can provide complementary benefits from improved compliance and cost-effectiveness compared with loose combinations of corresponding drugs. A new FDC of fimasartan/amlodipine/hydrochlorothiazide 60/10/25 mg is undergoing clinical development. A randomized, open-label, single-dose, 3-period, 3-sequence, partially replicated crossover phase 1 study was conducted to compare the pharmacokinetics (PKs) between the FDC of fimasartan/amlodipine/hydrochlorothiazide 60/10/25 mg and a loose combination of a dual-combination FDC (fimasartan/amlodipine 60/10 mg) and hydrochlorothiazide 25 mg. Sixty healthy subjects were randomized, and 55 subjects completed the study. Serial blood samples were collected, and plasma concentrations of fimasartan, amlodipine and hydrochlorothiazide were measured to analyze PK parameters. The PK profiles of the FDC were similar to those of the loose combinations. The geometric mean ratios (GMRs) and 90% confidence intervals (CIs) of the FDC to loose combinations for the maximum plasma concentration (C_max) and area under the curve until the last measurable time point (AUC_last) were within the conventional bioequivalent range of 0.80 to 1.25. The GMRs and 90% CIs of fimasartan, amlodipine and hydrochlorothiazide were 1.0163 (0.8681–1.1898), 0.9595 (0.9256–0.9946), and 1.1294 (1.0791–1.1821) for C_max and 1.0167 (0.9347–1.1059), 0.9575 (0.9317–0.9841), and 1.0561 (1.0170–1.0967) for AUC_last, respectively. Both the FDC and loose combinations were well tolerated. In conclusion, the FDC of fimasartan/amlodipine/hydrochlorothiazide 60/10/25 mg showed similar PK profiles to those of the corresponding loose combination, and both treatments were well tolerated.

A meta-analysis: efficacy and safety of anti-epileptic drugs prescribed in Korea as monotherapy and adjunctive treatment for patients with focal epilepsy

Focal epilepsy is the most common type of epilepsy in Korea, and anti-epileptic drugs (AEDs) are the main treatment option for patients. This study aimed to compare the efficacy and safety of AEDs for focal epilepsy through a meta-analysis. The AEDs prescribed in Korea as monotherapy and adjunctive treatment for patients with focal epilepsy were included for analysis. Relevant articles were searched for randomized clinical trials of AEDs and treatment outcomes were analyzed on the basis of the 50% responder rate, seizure-free rate, treatment withdrawal rate, and emergence rates of adverse events (AEs). The odds ratios (ORs) and their 95% confidence intervals (CI) of study outcome were calculated using combined data from multiple studies. A total of 47 studies were included in the meta-analysis. The seizure-free rate, treatment withdrawal rate, and AE rate were not significantly different among the AEDs recommended for monotherapy. Among the AEDs recommended for adjunctive treatment, topiramate and oxcarbazepine yielded the highest OR in comparison with placebo for each efficacy parameter: the 50% responder rate for topiramate = 6.42 (3.76–11.6) and the seizure-free rate for oxcarbazepine = 32.7 (6.05–899). The third-generation AEDs (brivaracetam and perampanel) yielded relatively better safety outcomes than other AEDs. In general, the 50% responder rate and treatment withdrawal rate tended to increase as the dose of the AEDs increased. The results from the current meta-analysis of the efficacy and safety data of various AEDs may provide insight into optimal pharmacotherapy for the treatment of focal epilepsy.

Evaluation of the pharmacokinetics and food effects of a novel formulation tamsulosin 0.4 mg capsule compared with a 0.2 mg capsule in healthy male volunteers

Tamsulosin, an alpha-1 adrenoreceptor antagonist, has been used as a primary option for medical treatment of benign prostate hyperplasia. An open-label, single-dose, randomized, three-treatment, three-period, three sequence crossover study was conducted to evaluate the pharmacokinetics (PKs) of 0.2 and 0.4 mg tamsulosin hydrochloride (HCl) in the fed versus the fasted state. Subjects were randomly assigned to three sequences and received one of the following treatments at each period: tamsulosin HCl 0.2 or 0.4 mg in the fed state with a high-fat meal, or tamsulosin HCl 0.4 mg in the fasted state. Blood samples for the PK analysis were collected at pre-dose and up to 48 h post-dose. The PK parameters were calculated by a non-compartmental method. The geometric mean ratio (GMR) and its 90% confidence intervals (CIs) of the plasma maximum concentration (C_max) and area under concentration curve from time zero to last measurable concentration (AUC_last) were calculated. Twenty-two subjects completed the study. The systemic exposure of tamsulosin 0.4 mg decreased approximately 9% in the fed state compared to the fasted state, and the time to reach peak concentration was slightly delayed in the fed state. The dose normalized GMR and its 90% CIs of C_max and AUC_last for 0.2 and 0.4 mg tamsulosin in the fed state were within 0.8 and 1.25 range. Systemic exposure of tamsulosin was decreased in the fed condition compared to the fasted condition. Linear PK profiles were observed between 0.2 and 0.4 mg tamsulosin in the fed state.

Trial Registration

ClinicalTrials.gov Identifier: NCT02529800.

Pharmacodynamics of tegoprazan and revaprazan after single and multiple oral doses in healthy subjects

BACKGROUND

Potassium-competitive acid blockers (P-CABs) are emerging as novel treatments for acid-related disorders including gastroesophageal reflux disease. Tegoprazan and revaprazan are approved P-CABs in South Korea, but the pharmacodynamics and safety/tolerability of the two drugs have never been compared.

AIMS

To evaluate the pharmacodynamics and safety/tolerability of tegoprazan and revaprazan after single and multiple oral doses METHODS: A randomised, open-label, active-controlled study was conducted in Helicobacter pylori-negative healthy Korean male subjects. Tegoprazan 50 mg or revaprazan 200 mg was administered orally, once daily for 7 days; 24-h intragastric pH monitoring and serum gastrin were measured for pharmacodynamic evaluation. Safety parameters including serum microRNA-122 (miR-122) level were also collected.

RESULTS

After a single dose, the %Time pH ≥4 for tegoprazan was greater than that for revaprazan (54.5% vs 25.1%). After multiple doses, the %Time pH ≥4 for tegoprazan was also greater than that for revaprazan (68.2% vs 25.3%). %Time pH ≥4 during 12 hours at nighttime for tegoprazan was greater than that for revaprazan (71.8% vs 31.9%). The changes in the serum gastrin were not clinically significant for either drug. Despite the slight increases of serum miR-122 for each drug, tegoprazan and revaprazan were well tolerated considering other safety parameters including AST and ALT levels.

CONCLUSION

Tegoprazan 50 mg showed stronger gastric acid suppression than revaorazan 200 mg. Both drugs were well tolerated.

Population Pharmacokinetic Analysis of Amikacin for Optimal Pharmacotherapy in Korean Patients with Nontuberculous Mycobacterial Pulmonary Disease

Amikacin is used as a therapy for patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) who are resistant to macrolide antibiotics or have severe symptoms. This study aimed to characterize the pharmacokinetic properties of amikacin in patients with NTM-PD by developing a population pharmacokinetic model and to explore the optimal pharmacotherapy in patients with NTM-PD. For this study, all data were retrospectively collected. The amikacin pharmacokinetic properties were best described by a two-compartment model with first-order elimination. The estimated glomerular filtration rate and body weight were identified as significant covariates for clearance and the volume of distribution, respectively. A model-based simulation was conducted to explore the probability of reaching the target therapeutic range when various dose regimens were administered according to the body weight and renal function. The simulation results indicated that the amikacin dosage should be determined based on the body weight, and for patients who weigh over 70 kg, it is necessary to adjust the dose according to renal function. In conclusion, the optimal pharmacotherapy of amikacin for patients with NTM-PD was recommended based on the population pharmacokinetic model, which is expected to enable the personalization of drug therapy and improve the clinical outcomes of amikacin therapy.

Development of a Pharmacokinetic Model Describing Neonatal Fc Receptor-Mediated Recycling of HL2351, a Novel Hybrid Fc-Fused Interleukin-1 Receptor Antagonist, to Optimize Dosage Regimen

HL2351 (hIL‐1Ra‐hyFc) is a novel recombinant protein formed by the fusion of two human interleukin‐1 receptor antagonist components into one antibody‐derived fragment crystallizable portion. Although HL2351 has a pharmacological mechanism of action similar to that of anakinra as a commercialized biopharmaceutical drug, HL2351 has been desired to reduce the dose frequency and improve therapeutic efficacy due to its long circulation half‐life. In this study, we aimed to develop a population pharmacokinetic (PK) model for HL2351 using a neonatal Fc receptor (FcRn)–mediated recycling model based on a quasi‐steady‐state approximation of target‐mediated drug disposition (TMDD) for the description of interactions between the drug and FcRn. FcRn recycling was expected in the case of HL2351 because of PK related to the antibody portion. A TMDD model was also applied to describe interactions of IL1R with HL2351 or anakinra. PK data were collected from a phase I study conducted in six groups (1, 2, 4, 8, 12 mg/kg HL2351 and 100 mg anakinra single subcutaneous administration; n = 8 per group). In consequence, the PK of anakinra and HL2351 following administration of multiple doses at different dosages were simulated. Optimized doses were considered based on average concentrations of IL1R bound to anakinra and HL2351. HL2351 at doses of 326 mg or 4.267, 4.982, 5.288, 5.458, or 5.748 mg/kg once weekly or HL2351 at 1726 mg or 21.92, 26.86, 29.10, 30.36, or 32.53 mg/kg once biweekly would have similar therapeutic effects with anakinra at a dose of 100 mg or 1, 2, 3, 4, or 8 mg/kg administered once daily, respectively.

Pharmacokinetics and Tolerability of LC28-0126, a Novel Necrosis Inhibitor, After Multiple Ascending Doses: A Phase I Randomized, Double-blind, Placebo-controlled Study in Healthy Male Subjects

PURPOSE

LC28-0126 is a reactive oxygen species scavenger being developed for the treatment of various conditions caused by oxidative stress, such as oral mucositis, graft-versus-host disease, and lethal reperfusion injury in acute myocardial infarction. The aim of this study was to assess the tolerability and pharmacokinetic properties of LC28-0126 with multiple IV administrations in healthy male subjects.

METHODS

A dose-block-randomized, double-blind, placebo-controlled, multiple ascending-dose study was conducted. Subjects received 3-, 10-, 20-, or 30-mg doses of LC28-0126 or inactive control vehicle, infused over 30 min, once daily for 7 days. Blood and urine samples were collected for pharmacokinetics assessment. Tolerability was assessed by the documentation of adverse events, including abnormal findings on physical examination, vital sign measurements, blood oxygen saturation monitoring, 12-lead ECG, continuous ECG monitoring, and clinical laboratory testing.

FINDINGS

A total of 32 subjects completed the study. After multiple dosing, the plasma concentration of LC28-0126 showed a steep decrease after infusion, followed by slow elimination. Systemic exposure of LC28-0126 was increased proportionally to doses ranging from 3 to 30 mg. The accumulation ratios were 2.58-2.79 on multiple dosing. The fractions excreted unchanged in urine were found to be <5%. All reported drug-related adverse events were injection-site reactions, and no serious adverse events were reported.

IMPLICATIONS

Multiple administrations of LC28-0126 exhibited a dose-proportional pharmacokinetic profile and were well tolerated at a dose range of 3-30 mg. ClinicalTrials.gov identifier: NCT03196804.

Pharmacokinetics of human antithrombin III concentrate in the immediate postoperative period after liver transplantation

AIMS

Antithrombin III (AT-III) concentrates have been used to prevent critical thrombosis in the immediate post-liver transplantation period without clear evidence regarding the optimal dose or administration scheme. The relationship between the AT-III dosage and the plasma activity levels during the period was evaluated in this study.

METHODS

The plasma AT-III activity levels and clinical data obtained from patients who received liver transplantation from January 2017 to September 2018 were retrospectively analysed. A population pharmacokinetic (PK) model was developed using nonlinear mixed-effects method and externally validated thereafter. Several dosing scenarios were simulated to maintain the plasma AT-III activity level within the normal range using the developed PK model to search for an optimal AT-III dosing regimen.

RESULTS

The plasma AT-III activity levels were best described by a single compartment model with first order elimination kinetics. The recovery of endogenous AT-III level during the postoperative days was modelled using an E_max model. The typical values (95% confidence interval) of volume of distribution and clearance were 3.86 (3.40-4.32) L, and 0.129 (0.111-0.147) L h^-1 , respectively. Serum albumin and body weight had significant effect on clearance and were included in the model. External validation of the proposed model demonstrated adequate prediction performance. Furthermore, simulation of previously suggested or modified dosing scenarios showed successful maintenance of AT-III activity level within the normal range.

CONCLUSION

A population PK model of AT-III concentrate was developed using data from liver recipients. Dosing scenarios simulated in our study may help establish a practical guide for AT-III concentrate titration after liver transplantation.

Safety, tolerability and pharmacokinetics and pharmacodynamics of HL2351, a novel hybrid fc-fused interleukin-1 receptor antagonist, in healthy subjects: A first-in-human study

AIMS

We performed a first-in-human study with HL2351, a novel hybrid Fc-fused interleukin (IL)-1 receptor antagonist, to evaluate its tolerability, pharmacokinetics and pharmacodynamics (PD) after a single subcutaneous (SC) administration in healthy subjects.

METHODS

A randomized, double-blind, placebo- and active-controlled, dose-escalation study was conducted. Eligible subjects randomly received a single SC administration of HL2351 (1, 2, 4, 8 and 12 mg/kg) or placebo in a ratio of 8:2. Subjects in the active-controlled group received a single SC administration of anakinra at 100 mg. Serial blood samples were collected for pharmacokinetics and PD analyses. An ex-vivo activation test was performed to evaluate the PD using peripheral blood mononuclear cells treated with IL-1β. Anti-HL2351 antibodies were determined at baseline and 29 days postdose. Tolerability was assessed throughout the study.

RESULTS

HL2351 was eliminated more slowly than anakinra (terminal half-life: 27.21-45.28 vs 3.97 h). Serum concentrations of HL2351 were increased dose-proportionally. The mean apparent clearance of HL2351 were 0.6, 0.66, 0.75, 0.51, 0.65 L/h at 1, 2, 4, 8 and 12 mg/kg, respectively. The percent inhibition of IL-6 expression varied widely (range: 0-92.1%), showing no clear trend or discernible difference between HL2351, anakinra and placebo. HL2351 was well tolerated after a single SC administration.

CONCLUSION

HL2351 was well tolerated and showed linear pharmacokinetic characteristics after a single SC administration at doses up to 12 mg/kg in healthy subjects. HL2351 remained in the body 7-11 times longer than anakinra. HL2351 can be developed as a potential therapeutic alternative to anakinra.

Recovery of renal function in patients with lupus nephritis and reduced renal function: the beneficial effect of hydroxychloroquine

Background

Reduced renal function is associated with worse renal outcome in patients with lupus nephritis (LN). However, there is insufficient knowledge regarding renal function recovery in patients with LN with reduced baseline renal function. Therefore, the present study aimed to investigate renal function recovery and related factors in patients with reduced baseline renal function.

Methods

The present retrospective longitudinal cohort study included patients with LN and reduced renal function. Reduced renal function was defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m2. Recovery of renal function was determined by an eGFR of >60 mL/min/1.73 m2 at six months after baseline, and factors associated with it were evaluated using logistic regression analysis.

Results

We included 90 patients with LN, with a mean eGFR value of 37.2 ± 13.9 mL/min/1.73 m2. Forty-six (51.1%) patients recovered their renal function after six months. On multivariate analysis, hydroxychloroquine use (odds ratio (OR) = 3.891, 95% confidence interval (CI) 1.196–12.653, p = 0.024), prolonged LN (OR = 0.926, 95% CI 0.874–0.981, p = 0.009) and high-grade tubular atrophy (OR = 0.451, 95% CI 0.208–0.829, p = 0.013) were associated with renal function recovery. During follow up, 25 patients were on end-stage renal disease (ESRD). Kaplan–Meier analysis revealed that renal function recovery after six months and lower probability of ESRD are associated.

Conclusions

In patients with LN and reduced renal function, renal function recovery at six months was associated with use of hydroxychloroquine and inversely related to longer duration of LN and higher grade of tubular atrophy.