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Cenobamate (XCOPRI and ONTOZRY) is a novel antiseizure medication for the treatment of focal‐onset seizures. Nonetheless, there is limited information on the pharmacokinetics (PKs), safety, and efficacy of cenobamate in Asian people, including Japanese people. This study aimed to evaluate the PKs and safety of cenobamate after a single oral dose in healthy Japanese subjects and to compare the PKs with that reported in non‐Japanese subjects. A randomized, double‐blind, placebo‐controlled, single ascending dose study was conducted at four dose levels of 50, 100, 200, and 400 mg. Subjects were randomly assigned to cenobamate or placebo in a 6:2 ratio. Cenobamate was rapidly absorbed, reaching its maximum plasma concentration (Cmax) in 0.75 to 2.25 h, and was eliminated with a mean half‐life of 37.0 to 57.7 h. The Cmax increased dose proportionally, whereas area under the concentration‐time curve increased more than dose proportionally, which was consistent with the findings in non‐Japanese subjects. The systemic exposure of cenobamate was comparable between Japanese and non‐Japanese subjects at all dose levels evaluated. All adverse events were mild in severity, and their incidence did not show dose‐dependent trends. Furthermore, there were no clinically significant issues in safety parameters, including sedation tests, neurologic examinations, and Columbia Suicide Severity Rating Scale interviews. In conclusion, the systemic exposure of cenobamate after a single dose in Japanese subjects increased by dose, which was similar to the pattern in non‐Japanese subjects. In addition, a single dose of cenobamate was well‐tolerated in the dose range of 50 to 400 mg in healthy Japanese subjects.

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.

Omeprazole blocks the gastric H+ /K+ adenosine triphosphatase, thus inhibiting gastric acid secretion, and is metabolized by cytochrome P450 (CYP) 2C19. Due to the physiological changes in the elderly, there are different pharmacokinetic consequences compared to young people. The aim of this study was to evaluate the pharmacokinetic profiles of omeprazole in 15 elderly participants according to the CYP2C19 genotype. The concentration-time profiles of omeprazole and its metabolites, 5-hydroxy (5-OH) omeprazole and omeprazole sulfone, were similar between the CYP2C19 extensive metabolizer (EM) and intermediate metabolizer groups. In contrast, when comparing the EM group and CYP2C19 poor metabolizer (PM) group, the EM/PM geometric mean ratio (95% confidence interval) of area under the plasma concentration-time curve from time of dosing to the last measurable concentration was 0.52 (0.27-1.01) and that of the IM group was 0.71 (0.32-1.59), indicating that the exposure of omeprazole in the PM group was increased. The exposure of 5-OH omeprazole was significantly decreased in the PM group when compared to the EM group, with an EM/PM geometric mean ratio (95% confidence interval) of 2.20 (1.50-3.22). In conclusion, the tendency of drug exposure according to the CYP2C19 genotype in the elderly and young adults was similar in that the exposure level was highest in the PM group. However, when compared to young adults, the difference between the genotype groups was smaller in the elderly.

This study aimed to demonstrate pharmacokinetic (PK) equivalence of a single dose of the proposed adalimumab biosimilar CT‐P17 to United States‐licensed adalimumab (US‐adalimumab) and European Union‐approved adalimumab (EU‐adalimumab). This double‐blind, parallel‐group, phase I trial (clinicaltrials.gov NCT03970824) was conducted at 10 hospitals (Republic of Korea), in which healthy subjects (1:1:1) were randomized to receive a single 40 mg (100 mg/ml) subcutaneous injection of CT‐P17, US‐adalimumab, or EU‐adalimumab. Primary end points were PK equivalence in terms of: area under the concentration–time curve from time zero to infinity (AUC0–inf); AUC from time zero to the last quantifiable concentration (AUC0–last); and maximum serum concentration (Cmax). PK equivalence was concluded if 90% confidence intervals (CIs) for percent ratios of geometric least squares means (GLSMs) for pairwise comparisons were within the equivalence margin of 80–125%. Additional PK end points, safety, and immunogenicity were evaluated. Of the 312 subjects who were randomized (103 CT‐P17; 103 US‐adalimumab; 106 EU‐adalimumab), 308 subjects received study drug. AUC0–inf, AUC0–last, and Cmax were equivalent among CT‐P17, US‐adalimumab, and EU‐adalimumab, because 90% CIs for the ratios of GLSMs were within the 80–125% equivalence margin for each pairwise comparison. Secondary PK end points, safety, and immunogenicity were similar between treatment groups. In conclusion, PK equivalence for single‐dose administration of CT‐P17, EU‐adalimumab, and US‐adalimumab was demonstrated in healthy adults. Safety and immunogenicity profiles were comparable between treatment groups and consistent with previous reports for adalimumab biosimilars.

Hypertension is more effectively treated with coadministration of 2 or more antihypertensive drugs than with high-dose monotherapy. Therefore, calcium channel blockers, angiotensin II receptor blockers, and thiazides are coadministered to treat hypertension. The objective of this study was to compare the pharmacokinetic (PK) profiles of HCP1401, a fixed-dose combination of amlodipine 5 mg, losartan 100 mg, and chlorthalidone 25 mg, with the separate components (loose combination) of amlodipine/losartan 5/100 mg and chlorthalidone 25 mg. A randomized, open-label, single-dose, 2-way crossover study was conducted. Blood samples for amlodipine and chlorthalidone were collected for up to 144 hours after dosing, whereas those for losartan were collected up to 48 hours after dosing. The PK parameters of these drugs were calculated using a noncompartmental method. Sixty subjects completed the study. The geometric mean ratios and 90% confidence intervals of maximum plasma concentration and area under the concentration-time curve to the last measurable point for amlodipine, losartan, and chlorthalidone were within the conventional bioequivalence range of 0.80 to 1.25. There were no clinically significant changes in safety assessments, and the treatments were well tolerated. The PK characteristics and tolerability profiles of a single oral FDC of amlodipine, losartan, and chlorthalidone were equivalent to those of individual tablets in a loose combination.

Sejung Hwang,1 Dae Young Lee,2 Joo-Youn Cho,1,3 Jae-Yong Chung,4 In-Jin Jang,1 Kyung-Sang Yu,1,3 SeungHwan Lee1 1Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Republic of Korea; 2Drug Metabolism and Pharmacokinetics (DMPK), Drug Evaluation, Dong-A ST Research Institute, Gyonggi-do, Republic of Korea; 3Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea; 4Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Bundang Hospital, Seongnam, Republic of KoreaCorrespondence: SeungHwan LeeDepartment of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of KoreaTel +82-2-2072-2343Fax +82-2-2072-0720Email leejh413@snu.ac.krPurpose: DA-8031 is a novel selective serotonin reuptake inhibitor for the treatment of premature ejaculation. This study investigated the pharmacokinetics, safety and tolerability of multiple oral doses of DA-8031. In addition, a genetic analysis was explored to evaluate the effect of genetic polymorphisms on the pharmacokinetics of DA-8031.Subjects and Methods: A dose block-randomized, double-blind, placebo-controlled study was conducted in 3 dose groups with 20, 30 and 40 mg of DA-8031. Healthy male subjects were randomized to DA-8031 or placebo at a 4:1 ratio in each dose group of 10 subjects by oral administration once daily for 7 consecutive days. Serial blood and urine samples were collected for the pharmacokinetic evaluation, and the pharmacokinetic-related genes were analyzed by DMETTM plus. A safety evaluation was conducted including adverse events (AEs) monitoring and 12-lead electrocardiogram (ECG).Results: The plasma DA-8031 concentration reached the maximum concentration (Cmax) in 2.2 to 3.0 h and was eliminated with a mean half-life of 25.5 to 26.7 h at steady state. The accumulation index of DA-8031 ranged 2.3 to 2.8. The systemic exposure of DA-8031 of the CYP2D6 intermediate metabolizer (IM) was significantly higher compared to the CYP2D6 poor metabolizer (PM). There were no clinically significant QTc interval changes, and all the adverse events were mild.Conclusion: After multiple oral doses of DA-8031 20, 30, and 40 mg in this study, the systemic exposure of DA-8031 increased in a more than dose-proportional manner with the increasing doses, and DA-8031 was generally well tolerated. In addition, the genetic polymorphisms of CYP2D6 have an impact on the pharmacokinetics of DA-8031.Keywords: selective serotonin reuptake inhibitors, clinical pharmacology, phase 1 study, pharmacogenomics

Natural protopanaxadiol ginsenosides exhibit low absorption in the human intestine. However, ginsenoside compound K (CK) with 1 conjugated glucose molecule exhibits favorable absorption. The purpose of this study was to compare the pharmacokinetics of ginsenoside CK from a CK fermentation product, CK-30, and from a red ginseng extract. A randomized, open-label, 2-treatment, 2×2 crossover study was conducted. The volunteers were randomly divided into 2 groups. One group received CK-30, and the other group received 2.94 g of a red ginseng extract. After a 7-day washout period, the subjects received an alternative treatment for a single dose. The pharmacokinetic parameters, including the maximum plasma concentration (Cmax ) and area under the plasma concentration-time curve from time 0 to time of last measurable concentration, were calculated. The median time to reach Cmax of ginsenoside CK after administration of CK-30 was 3.0 hours, whereas the corresponding value of the red ginseng extract was 10.0 hours. Compared with the red ginseng extract, CK-30 resulted in a higher systemic exposure to ginsenoside CK, with a 118.3-fold increase in Cmax and a 135.1-fold increase in area under the plasma concentration-time curve from time 0 to time of last measurable concentration. The systemic exposure to ginsenoside CK was significantly higher after administration of CK-30 than red ginseng extract.

Inseung Jeon,1,* Jaeseong Oh,1,* Yu-Kyung Kwon,2 Seo Hyun Yoon,1 Joo-Youn Cho,1 In-Jin Jang,1 Kyung-Sang Yu,1 SeungHwan Lee1 1Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Republic of Korea; 2Department of Clinical Research, Chong Kun Dang, Seoul, Republic of Korea*These authors contributed equally to this workCorrespondence: SeungHwan LeeDepartment of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of KoreaTel +82 2 2072 2343Fax +82 2 742 9252Email leejh413@snu.ac.krIntroduction: 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 Cmax, AUC0–last and AUC0–∞ 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.Keywords: pharmacokinetics, pharmacodynamics, biosimilar, darbepoetin alfa

Tenofovir is the representative treatment for human immunodeficiency virus and hepatitis B virus infection. This study was conducted to assess the pharmacokinetics (PKs) and safety characteristics after a single administration of tenofovir disoproxil phosphate compared to tenofovir disoproxil fumarate in healthy male subjects. An open-label, randomized, single administration, two-treatment, two-sequence crossover study was conducted in 37 healthy volunteers. Serial blood samples were collected up to 72 hours. Non-compartmental analysis was used to calculate the PK parameters. The 90% confidence intervals (90% CIs) of the geometric mean ratio (GMR) were calculated for comparing tenofovir disoproxil phosphate to tenofovir disoproxil fumarate. Safety assessments were performed including clinical laboratory tests, adverse events, etc. during the study. The GMR and 90% CIs were 1.0514 (0.9527-1.1603) for Cmax and 1.0375 (0.9516-1.1311) for AUClast, respectively, and both fell within the conventional bioequivalence range of 0.8-1.25. Both tenofovir salt forms were tolerable. This study demonstrated that tenofovir disoproxil phosphate (292 mg) was bioequivalent to tenofovir disoproxil fumarate (300 mg).

The absorption, metabolism, and excretion (AME) profiles of KD101, currently under clinical development to treat obesity, were assessed in humans using accelerator mass spectrometry (AMS) after a single oral administration of KD101 at 400 mg and a microdose of 14 C-KD101 at ~ 35.2 μg with a total radioactivity of 6.81 kBq. The mean total recovery of administered radioactivity was 85.2% with predominant excretion in the urine (78.0%). The radio-chromatographic metabolite profiling showed that most of the total radioactivity in the plasma and the urine was ascribable to metabolites. The UDP-glucuronosyltransferase (UGT), including UGT1A1, UGT1A3, and UGT2B7, might have contributed to the interindividual variability in the metabolism and excretion of KD101. The microtracing approach using AMS is a useful tool to evaluate the AME of a drug under development without risk for high radiation exposure to humans.

Purpose Evogliptin, a dipeptidyl peptidase-4 inhibitor, and glimepiride, a sulfonylurea, are used to treat type 2 diabetes mellitus. In this study, we aimed to evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) interactions between evogliptin and glimepiride. Materials and Methods A randomized, open-label, 3-period, 3-treatment, 2-sequence crossover study was conducted in healthy male subjects. During each period, subjects received multiple doses of evogliptin 5 mg alone (EVO), glimepiride 4 mg alone (GLI), or a combination of the two (EVO+GLI). Serial blood and urine samples were collected 168 and 24 h post dosing, respectively, for PK and PD analyses. Results Thirty-four subjects completed the study. The co-administration of evogliptin and glimepiride did not alter their plasma and urine PK profiles. For evogliptin, the geometric mean ratio (GMR) (90% confidence intervals) for the maximum plasma concentrations at steady-state (Cmax,ss) and the area under the curve during dosing interval at steady-state (AUCτ,ss) of EVO+GLI to E were 1.02 (0.98–1.06) and 0.97 (0.95–1.00), respectively. For glimepiride, the corresponding values of EVO+GLI to GLI were 1.08 (1.01–1.17) and 1.08 (1.02–1.14), respectively. All values were within the regulatory bioequivalence criteria of 0.8–1.25. Glucose excursion decreased with the co-administration of evogliptin and glimepiride compared with that observed with the evogliptin or glimepiride monotherapy. Conclusion Evogliptin and glimepiride had no PK interactions when co-administered, while the combination therapy showed an additive glucose-lowering effect compared to those of evogliptin or glimepiride monotherapy.

Aim Evogliptin is a newly developed oral glucose-lowering medication of the dipeptidyl peptidase 4 (DPP-4) inhibitor class for type 2 diabetes mellitus. The combination of a DPP-4 inhibitor with pioglitazone is a promising therapeutic option. The aim of the present study was to evaluate the pharmacokinetic and pharmacodynamic interaction between evogliptin and pioglitazone. Materials and methods A randomized, open-label, multiple-dose, three-treatment, three-period, six-sequence crossover study was conducted in healthy Korean male subjects. All subjects received evogliptin 5 mg once daily for 7 days (EVO), pioglitazone 30 mg once daily for 7 days (PIO) and co-administration of evogliptin 5 mg and pioglitazone 30 mg once daily for 7 days (EVO+PIO) according to the assigned sequence and period. Serial blood samples were collected for 24 hours for pharmacokinetic analysis and 3 hours after the oral glucose tolerance test for the pharmacodynamic analysis. Results Thirty-four subjects completed the study. EVO+PIO and EVO showed a similar maximum plasma concentration at steady state (Cmax,ss) and area under the concentration-time curve during the dosing interval at the steady state (AUCτ,ss) of evogliptin, with geometric mean ratios (GMRs) (90% confidence interval (CI)) of 1.01 (0.97-1.05) and 1.01 (0.98-1.04), respectively. EVO+PIO and PIO showed a similar Cmax,ss and AUCτ,ss of pioglitazone, with GMRs (90% CI) of 1.07 (0.99-1.17) and 1.08 (0.99-1.17), respectively. Reduction of the glucose level after EVO+PIO was larger compared to PIO and similar with EVO. Conclusion Concomitant administration of evogliptin and pioglitazone showed similar glucose-lowering effects with those of evogliptin alone without pharmacokinetic interactions when compared to the intake of each drug alone.

Objective Asthma patients often have co-existing symptoms of allergic rhinitis and are often prescribed with both asthma and rhinitis treatments such as montelukast and levocetirizine. The objective of this study was to compare the pharmacokinetic profiles of a montelukast/levocetirizine fixed-dose combination chewable tablet with individual administration of montelukast and levocetirizine in healthy subjects. Materials and methods A randomized, open-label, single-dose crossover study was conducted in healthy male subjects. One of the following treatments was administered in each period: co-administration of 1 chewable tablet of montelukast 5 mg and 1 tablet of levocetirizine 5 mg or administration of 1 chewable tablet of montelukast/levocetirizine 5/5 mg fixed-dose combination. Serial blood samples were collected up to 48 hours post dose. Plasma drug concentrations were measured by liquid chromatography/tandem mass spectrometry. Pharmacokinetic parameters, including maximum plasma concentration (Cmax) and area under the plasma concentration versus time curve from dosing to the last measurable concentration (AUClast), were determined by non-compartmental analysis. The geometric least-square mean (GLSM) ratios and associated 90% confidence intervals (CIs) of Cmax and AUClast were calculated to evaluate pharmacokinetic equivalence. Results A total of 22 subjects were included in pharmacokinetic analysis. The GLSM ratios and 90% CIs of Cmax and AUClast were 1.0054 (0.9535 - 1.0601) and 1.0628 (1.0013 - 1.1281) for montelukast and 1.0105 (0.9488 - 1.0764) and 1.0396 (0.9935 - 1.0879) for levocetirizine, respectively. Conclusion The pharmacokinetic parameters of montelukast and levocetirizine when administered as separate tablets or as a fixed-dose combination were compared, and the parameters met the pharmacokinetic equivalence criteria. (ClinicalTrials.gov Identifier: NCT03371849).

Purpose Patients with type 2 diabetes mellitus require strict blood glucose control, and combination therapy with a thiazolidinedione and dipeptidyl peptidase-4 inhibitors, such as lobeglitazone and sitagliptin, is one of the recommended treatments. The objective of this study was to investigate a possible pharmacokinetic interaction between lobeglitazone and sitagliptin after multiple oral administrations in healthy Korean men. Methods Two randomized, open-label, multiple-dose, 2-way crossover studies were conducted simultaneously in healthy men. In study 1, men were randomly assigned to 1 of 2 sequences, and 1 of the following treatments was administered in each period: 1 tablet of lobeglitazone sulfate (0.5 mg) once daily for 5 days and or 1 tablet each of lobeglitazone sulfate (0.5 mg) and sitagliptin (100 mg) once daily for 5 days. In study 2, men were also randomly assigned to 1 of 2 sequences and the treatments were as follows: 1 tablet of sitagliptin (100 mg) once daily for 5 days or 1 tablet each of sitagliptin (100 mg) and lobeglitazone sulfate (0.5 mg) once daily for 5 days. Serial blood samples were collected up to 48 h after dosing on the fifth day. Plasma drug concentrations were measured by LC-MS/MS. Pharmacokinetic parameters, including Cmax,ss and AUC0–τ , were determined by noncompartmental analysis. The geometric least-square mean (GLSM) ratios and associated 90% CIs of log-transformed Cmax,ss and AUC0–τ for separate or coadministration were calculated to evaluate pharmacokinetic interactions. Findings Nineteen men from study 1 and 17 from study 2 completed the pharmacokinetic sampling and were included in the analyses. The GLSM ratios of Cmax,ss and AUC0–τ were 0.9494 (95% CI, 0.8798–1.0243) and 1.0106 (95% CI, 0.9119–1.1198) for lobeglitazone (from study 1) and 1.1694 (95% CI, 1.0740–1.2732) and 1.0037 (95% CI, 0.9715–1.0369) for sitagliptin (from study 2), respectively. Implications Except for the slight 17% increase in the sitagliptin Cmax,ss value, the pharmacokinetic parameters of lobeglitazone and sitagliptin met the pharmacokinetic equivalent criteria when administered separately or in combination. The increase in Cmax of sitagliptin when coadministered with lobeglitazone would not be clinically significant in practice. ClinicalTrials.gov Identifier: NCT02824874 and NCT02827890 .

High pharmacokinetic variability of voriconazole is mainly explained by CYP2C19 phenotype, but there are still unknown factors affecting the variability. In this study, the effect of solute carrier organic anion transporter family member 2B1 (SLCO2B1) genotype on the pharmacokinetics (PKs) of voriconazole was evaluated in 12 healthy CYP2C19 poor metabolizers after a single administration of voriconazole 200 mg intravenously and orally. In addition, the influence of CYP3A4 enzyme activity was also explored. The oral absorption of voriconazole was decreased and delayed in the subjects with the SLCO2B1 c.*396T>C variant compared to the subjects with wild type. However, the CYP3A activity markers measured in this study did not show significant association with metabolism of voriconazole. The results suggest that the SLCO2B1 c.*396T>C may be associated with the decreased function of intestinal OATP2B1, and it could contribute to interindividual PK variability of voriconazole.

OBJECTIVE Therapeutic drug monitoring (TDM) of antiepileptic drugs (AEDs) helps optimize drug management for patients with epilepsy. Salivary testing is both noninvasive and easy, and has several other advantages. Due to technical advances, salivary TDM has become feasible for several drugs, including AEDs, and its value has been investigated. Until recently, saliva TDM of perampanel (PER) had not been reported. The purpose of our study was to confirm whether saliva is a biological substitute for plasma in PER TDM. METHODS Adult patients diagnosed with epilepsy who received PER from August 2018 to March 2019 at Seoul National University Hospital were enrolled. Total and free PER were measured in simultaneously obtained plasma and saliva samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and high-performance liquid chromatographic (HPLC). We examined the correlations between saliva and plasma PER concentrations and whether the use of concomitant medications classified as cytochrome P450 (CYP)3A4 inducers affected the correlations. RESULTS Thirty patients were enrolled, aged 16 to 60; 10 (33%) were women. Patients received 2 to 12 mg (mean, 6 mg) of PER. The average total and free concentrations of PER were 343.02 (46.6-818.0) and 1.53 (0.51-2.92) ng/mL in plasma and 9.74 (2.21-33.0) and 2.83 (1.01-6.8) ng/mL in saliva, respectively. A linear relationship was observed between the total PER concentrations in saliva and the total and free PER concentrations in plasma (both P

Purpose Hypertension is a major risk factor for cardiovascular diseases, necessitating hypertension control. Antihypertensive drugs are more potent when administered in combinations of 2 or 3 different classes of drugs. One such therapy includes a combination of an angiotensin receptor blocker, a calcium channel blocker, and a diuretic. The objective of this study was to evaluate the pharmacokinetic interaction among telmisartan, amlodipine, and hydrochlorothiazide. Methods : A randomized, open-label, 3-period, 6-sequence, 3-treatment, single-dose crossover study was conducted in healthy male subjects. Subjects were randomly assigned to 1 of 6 sequences and one of the following treatments was administered in each period: treatment A, co-administration of one tablet of telmisartan 80 mg and one tablet of amlodipine 10 mg; treatment B, one tablet of hydrochlorothiazide 25 mg alone; and treatment C, co-administration of all 3 investigational products. Serial blood samples were collected up to 144 hours postdose. Plasma drug concentrations were measured by using LC/MS–MS. Pharmacokinetic parameters, including Cmax and AUC0–last, were determined by using noncompartmental analysis. The geometric least squares mean ratios and associated 90% CIs of log-transformed Cmax and AUC0–last for separate administration or co-administration were calculated to evaluate pharmacokinetic interactions. Findings Twenty-seven subjects completed the study. The geometric least squares mean ratios and 90% CIs of Cmax and AUC0–last were 1.02 (0.85–1.21) and 1.04 (0.97–1.13) for telmisartan; 1.00 (0.95–1.04) and 0.95 (0.91–0.99) for amlodipine; and 0.88 (0.82–0.96) and 0.86 (0.82–0.90) for hydrochlorothiazide, respectively. No serious adverse events were recorded, and all reported adverse events were of mild intensity. Implications The pharmacokinetic parameters of telmisartan, amlodipine, and hydrochlorothiazide when administered separately or co-administered were compared, and all the parameters met the criteria for pharmacokinetic equivalence. Combination therapy of these 3 drugs had no significant impact on the pharmacokinetic parameters of each drug. (ClinicalTrials.gov Identifier: NCT03889145)

Eunwoo Kim,1 Kyoung Ryun Park,1 In-Jin Jang,1 Kyung-Sang Yu,1 SeungHwan Lee1,2 1Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Republic of Korea; 2Clinical Trials Center, Seoul National University Hospital, Seoul, Republic of KoreaCorrespondence: SeungHwan LeeDepartment of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of KoreaTel +82-2-2072-3520Fax +82-2-742-9252Email leejh413@snu.ac.krPurpose: Fixed-dose combination (FDC) of gemigliptin and rosuvastatin may improve medication compliance of patients with comorbid type 2 diabetes and dyslipidemia. Pharmacokinetics (PK), pharmacodynamics (PD), and safety of gemigliptin/rosuvastatin 50/20 mg FDC was compared with a loose combination of individual tablets in healthy subjects.Patients and methods: A randomized, open-label, single-dose, two-period, two-sequence, two-treatment crossover study was conducted. Subjects received FDC or a loose combination of gemigliptin (50 mg) and rosuvastatin (20 mg) during each period, with a 14-day washout. Serial blood samples were collected up to 72 hrs after dosing to measure plasma concentrations of gemigliptin, its active metabolite LC15-0636, and rosuvastatin for PK assessment, and DPP-4 activity for PD assessment. PK and PD parameters were calculated using a non-compartmental method. Safety profiles were evaluated throughout the study.Results: Thirty-seven subjects completed the study. The concentration-time profiles of gemigliptin, LC15-0636, and rosuvastatin were similar between FDC and loose combination, respectively. For each of the three compounds, the geometric mean ratios (90% confidence interval) of FDC to loose combination for Cmax and AUClast fell within the bioequivalence range of 0.8–1.25. Inhibition of DPP-4 activity–time profiles after administration of FDC and loose combination was overlapping, and Imax and AUEClast were similar. Both FDC and the loose combination were well tolerated.Conclusion: PK, PD, and safety profiles of gemigliptin, its metabolite, and rosuvastatin were similar between FDC and loose combination. The FDC of gemigliptin (50 mg) and rosuvastatin (20 mg) can be used as an alternative to a loose combination, which is expected to improve patient compliance.Keywords: DPP-4 inhibitor, statin, type 2 diabetes, dyslipidemia, pharmacokinetics

IntroductionChronic pain is highly prevalent and associated with a large burden of illness; there is a pressing need for safe, home-based, non-pharmacological, interventions. Virtual reality (VR) is a digital therapeutic known to be effective for acute pain, but its role in chronic pain is not yet fully elucidated. Here we present a protocol for the National Institute of Health (NIH) Back Pain Consortium (BACPAC) VR trial that evaluates the effectiveness of three forms of VR for patients with chronic lower back pain (cLBP), a highly prevalent form of chronic pain.Methods and analysisThe NIH BACPAC VR trial will randomise 360 patients with cLBP into one of three arms, each administered through a head-mounted display: 1) skills-based VR, a program incorporating principles of cognitive behavioural therapy, mindful meditation and physiological biofeedback therapy using embedded biometric sensors; 2) distraction-based VR, a program using 360-degree immersive videos designed to distract users from pain; and 3) sham VR, a non-immersive program using two-dimensional videos within a VR headset. Research participants will be monitored for 12 weeks using a combination of patient-reported outcomes administered via REDCap (Research Electronic Data Capture), wearable sensor data collected via Fitbit Charge 4 and electronic health record data. The primary outcome will be the NIH Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference scale. Secondary outcomes will include PROMIS Anxiety, PROMIS Sleep Disturbance, opioid prescription data and Pain Catastrophizing Scale Short Form. A subgroup analysis will explore patient level predictors for VR efficacy.Ethics and disseminationEthics approval was obtained from the Institutional Review Board of Cedars-Sinai Health System in April 2020. The results will be disseminated in a peer-reviewed journal.Trial registration numberNCT04409353.

Aims Although metformin has been reported to affect the gut microbiome, the mechanism has not been fully determined. We explained the potential underlying mechanisms of metformin through a multiomics approach. Methods An open-label and single-arm clinical trial involving 20 healthy Korean was conducted. Serum glucose and insulin concentrations were measured, and stool samples were collected to analyze the microbiome. Untargeted metabolomic profiling of plasma, urine, and stool samples was performed by GC-TOF-MS. Network analysis was applied to infer the mechanism of the hypoglycemic effect of metformin. Results The relative abundances of Escherichia, Romboutsia, Intestinibacter, and Clostridium were changed by metformin treatment. Additionally, the relative abundances of metabolites, including carbohydrates, amino acids, and fatty acids, were changed. These changes were correlated with energy metabolism, gluconeogenesis, and branched-chain amino acid metabolism, which are major metabolic pathways related to the hypoglycemic effect. Conclusions We observed that specific changes in metabolites may affect hypoglycemic effects through both pathways related to AMPK activation and microbial changes. Energy metabolism was mainly related to hypoglycemic effects. In particular, branched-chain amino acid metabolism and gluconeogenesis were related to microbial metabolites. Our results will help uncover the potential underlying mechanisms of metformin through AMPK and the microbiome.

Objective Varenicline is an efficacious aid for smoking cessation. In this study, the pharmacokinetics and safety were compared between film-coated tablets of varenicline tartrate (reference drug) and the newly developed orally disintegrating films of varenicline salicylate (test drug), both of them contained 1 mg of varenicline. Materials and methods A randomized, open-label, single-dose, two-sequence, two-period crossover study was conducted in healthy male subjects. Serial blood samples were obtained for up to 72 hours in each period, with a washout period of 7 days or more. The pharmacokinetic parameters were calculated using the noncompartmental method. Safety profiles were assessed throughout the study. Results A total of 28 subjects completed the study. The plasma varenicline concentration-time profiles were similar for the two study drugs. The maximum plasma varenicline concentration (Cmax) was 5,768.95 ng/L (mean) and 5,780.55 ng/L for the test drug and reference drug, respectively. The areas under the concentration-time curve from time 0 to the last measurable time point (AUC0-t) were 94,086.30 h×ng/L and 89,958.55 h×ng/L for the test drug and reference drug, respectively. The geometric mean ratios (90% confidence intervals) of the test drug to the reference drug for Cmax and AUC0-t were 0.9955 (0.9488 - 1.0444) and 1.0449 (0.9848 - 1.1088), respectively, which fell within the bioequivalence range of 0.8 - 1.25. There was no difference in safety between the study drugs. Conclusion The pharmacokinetics and safety profiles were similar between the two study drugs. The orally disintegrating film of varenicline salicylate can be an alternative to varenicline tartrate tablets.

Aims Helicobacter pylori (Hp) eradication plays a key role in the treatment and prevention of peptic ulcer diseases. Increasing clarithromycin resistance in Hp necessitates more effective treatments for eradication, such as bismuth-containing quadruple therapy. We aimed to compare the safety and pharmacokinetics (PK) of bismuth between vonoprazan- and lansoprazole-containing quadruple therapy in Hp-positive subjects. Methods In this randomised, double-blind, parallel-group study, Hp-positive subjects were randomised to receive vonoprazan- or lansoprazole-containing quadruple therapy. Each subject received vonoprazan 20 mg or lansoprazole 30 mg combined with bismuth 220 mg, clarithromycin 500 mg and amoxicillin 1000 mg twice daily for 14 days. Blood sampling and urine collection for bismuth PK were conducted predose and up to 12 hours postdose at steady-state. The PK parameters of bismuth were derived using a noncompartmental method and compared between treatments. An exploratory breath test for Hp was conducted at screening and at the follow-up visit on day 42. Safety was assessed by adverse event monitoring, physical examinations, vital signs, 12-lead electrocardiograms and clinical laboratory tests. Results A total of 30 subjects were randomised and 26 subjects completed the study (12 in the vonoprazan group and 14 in the lansoprazole group). The systemic exposure of bismuth in the 2 treatments was comparable (~5% difference). All subjects turned negative for Hp at the follow-up visit. No significant difference in safety profiles was noted between the 2 treatments. Conclusion The systemic exposure of bismuth was similar between vonoprazan- and lansoprazole-containing quadruple therapy. Vonoprazan-containing quadruple therapy was safe and well tolerated.

Body surface area (BSA)-based carboplatin dosing is used in various centers due to practical issues of renal function-based dosing with area under the curve (AUC) measurement. Pharmacokinetic (PK) analysis of high-dose carboplatin was performed in pediatric solid tumor patients undergoing high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT) with BSA-based dosing to calculate the AUCs achieved with this dosing method and to find the correlation between the PK and the renal functions and the adverse events. Carboplatin was administered as once daily intravenous doses at 300, 400, or 500 mg/m2/day over 1 h for 3 or 4 days. On the first and the last day of carboplatin administration, PK samplings were done at 0, 1, 2, and 5 h and only at 0 h on any other days. Mean AUC on the first and the last day were 4.85 ± 0.95 min × mg/mL and 5.27 ± 1.04 min × mg/mL, respectively (n = 23). Overall, negative correlations between the renal functions and the AUCs were mild to moderate, but they were stronger in nephrectomized patients. 51Cr-EDTA clearance decreased with statistical significance with each additional dose of carboplatin (P = 0.020). Optimal high-dose carboplatin dosing method and optimal target AUCs for the different tumors need further analysis.

Dongseong Shin,1–3 Sang-In Park,4,5Hong-Sub Lee,6 Kyung-Mi An,6 Juyoung Jung,6 MyongJae Lee,6 Kyung-Sang Yu31Department of Pharmacology, Gachon University College of Medicine, Incheon, Korea; 2Clinical Trials Center, Gachon University Gil Medical Center, Incheon, Korea; 3Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Korea; 4Department of Clinical Pharmacology and Therapeutics, Kyung Hee University Hospital, Seoul, Korea; 5East-West Medical Research Institute, Kyung Hee University, Seoul, Korea; 6Research Laboratories ILDONG Pharmaceutical Co. Ltd, Hwaseong, KoreaBackground and objective: IDP-73152 mesylate is a peptide deformylase inhibitor under investigation for the treatment of complicated skin and respiratory tract infections. The objective of this study was to investigate the pharmacokinetic (PK) profile and tolerability of IDP-73152 and the effect of food after a single oral administration.Methods: A dose block-randomized, double-blind, placebo-controlled, dose-escalation study was conducted. A total of 56 healthy volunteers received IDP-73152 mesylate in a single oral dose of 40, 80, 160, 320, 640, or 1280 mg in the fasted and fed (640 mg only) states. Blood and urine samples for PK analysis were collected up to 48 h post dose.Results: The area under the plasma concentration-time curve (AUC0-t) of IDP-73152 increased in a dose-proportional manner in the range of 40–320 mg. The mean terminal half-life decreased from 10.7 to 6.2 hrs as the dose increased. The fraction excreted unchanged in the urine ranged from 0.05 to 0.12. In the 640-mg dose group, food delayed the median time to peak concentration (tmax) from 0.9 to 3.5 hrs. Furthermore, the maximum plasma concentration (Cmax) were decreased by 36.2%; however, AUC0-t was not generally affected. No serious adverse event or clinically significant findings were observed.Conclusions: The systemic exposure of IDP-73152 proportionally increased as the dose increased up to 320 mg. The rate of absorption and extent of exposure were reduced by food intake. IDP-73152 was well tolerated without clinically significant adverse effects after a single oral administration.Keywords: phase I, pharmacokinetics, antibiotics, peptide deformylase inhibitor

Seol Ju Moon,1,2Ji-Young Jeon,1 Kyungho Jang,1 Kyung-Sang Yu,2 Yeji Lim,3 Min-Gul Kim1,4–51Center for Clinical Pharmacology, Biomedical Research Institute, Chonbuk National University Hospital, Jeonju, Republic of Korea; 2Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Republic of Korea; 3Yuhan Research Institute, Yuhan Corporation, Seoul, Republic of Korea; 4Research Institute of Clinical Medicine of Chonbuk National University, Jeonju, Republic of Korea; 5Department of Pharmacology, School of Medicine, Chonbuk National University, Jeonju, Republic of KoreaPurpose: Hypertension and dyslipidemia are major risk factors for cardiovascular diseases, and reduction of cardiovascular risks can be achieved by combining antihypertensive therapy with statins. The objective of this study was to evaluate the pharmacokinetic interaction between telmisartan/amlodipine fixed dose combination and rosuvastatin in healthy Korean male volunteers.Patients and methods: An open-label, two-cohort, multiple-dose, single-sequence crossover study was conducted in healthy male subjects. In Cohort 1, the subjects were administered one tablet of telmisartan/amlodipine 80mg/5mg once daily for 14days with or without one tablet of rosuvastatin 20mg once daily. In Cohort 2, the subjects were administered one tablet of rosuvastatin 20mg once daily for 14days with or without one tablet of telmisartan/amlodipine 80mg/5mg once daily. Serial blood samples were collected up to 24hrs post-dose on the 9th and 14th days in Cohort 1 and on the 5th and 14th days in Cohort 2. Plasma drug concentrations were measured by liquid chromatography/tandem mass spectrometry. Pharmacokinetic parameters, including maximum plasma concentration at steady state (Cmax,ss) and area under the plasma concentration versus time curve over dosing interval (AUCτ,ss), were determined by non-compartmental analysis. The geometric least-square mean (GLSM) ratios and associated 90% confidence intervals (CIs) of log-transformed Cmax,ss and AUCτ,ss for separate or concurrent therapy were calculated to evaluate pharmacokinetic interactions.Results: Thirty-eight subjects from Cohort 1 and nineteen subjects from Cohort 2 completed the study. The GLSM ratios and 90% CIs of Cmax,ss and AUCτ,ss, were 0.9829 (0.8334–1.1590) and 1.0003 (0.9342–1.0710) for telmisartan; 0.9908 (0.9602–1.0223) and 1.0081 (0.9758–1.0413) for amlodipine; and 2.2762 (2.0113–2.5758) and 1.3261 (1.2385–1.4198) for rosuvastatin, respectively.Conclusion: The pharmacokinetic parameters of telmisartan/amlodipine, but not rosuvastatin, met the pharmacokinetic equivalent criteria. The increase in systemic exposure to rosuvastatin caused by telmisartan/amlodipine co-administration would not be clinically significant in practice. Nevertheless, an appropriately designed two-sequence crossover study is needed to confirm the results of this study.Keywords: drug–drug interactions, pharmacokinetics, phase I, antihypertensive, statins

Background and objective: The effects of age and related factors on insulin sensitivity have not been definitively evaluated in East Asian populations. We proposed a reference range for the glucose disposal rate (M-value) on hyperinsulinemic-euglycemic study and its association with other parameters. Methods: Healthy, non-diabetic young (n=10) and elderly (n=13) male subjects with normal body mass index were eligible for this study. Subjects who passed the oral glucose tolerance test (OGTT) underwent hyperinsulinemic-euglycemic clamp with high-dose (80 mU/m2·min) insulin infusion. Results: M-values were normalized to body weight (MBW) and fat-free mass (MFFM). Neither M-value was significantly different between age groups (P=0.458 and P=0.900, respectively). An inverse correlation was observed between MFFM and baseline insulin (r=-0.418; P=0.047), baseline C-peptide (r=-0.426; P=0.043) and OGTT 2-hour glucose (r=-0.452; P=0.030). Regarding correlations with other insulin sensitivity indices, M-values were positively associated with the Matsuda index but not with homeostasis model assessment of insulin resistance. Conclusion: Our results suggest that age is not a critical determinant of insulin sensitivity, while fasting insulin and C-peptide levels, OGTT 2-hour glucose level, and Matsuda index are predictable markers of insulin sensitivity in healthy Koreans.

Ursodeoxycholic acid (UDCA) is a secondary bile acid component used for treating primary biliary cirrhosis. This study evaluated and compared the pharmacokinetic (PK) profiles of UDCA and its conjugates glyco-UDCA (G-UDCA) and tauro-UDCA (T-UDCA) in healthy elderly subjects and younger adults. In this randomized, open-label, 2-treatment, 1-sequence, and parallel study, subjects received 400 or 800 mg UDCA on day 1, followed by 200 mg UDCA twice daily for 2 weeks. Blood samples were obtained up to 24 hours after the first UDCA dose. Changes in miRNA-122, γ-glutamyl transferase, aspartate aminotransferase, and alanine aminotransferase levels from baseline were assessed to determine the safety and pharmacological effects of UDCA. This study examined the outcomes of 16 elderly subjects and 16 younger adults. Dose-normalized peak concentration of and systemic exposure to UDCA were 2 to 4 times higher, and the corresponding values of G-UDCA and T-UDCA were 1.7 times higher in the elderly subjects than in the younger adults. The subjects in both groups showed multiple peak profiles of UDCA and its conjugates. The miRNA-122 levels and hepatic enzyme test results were within the normal range in the elderly subjects after multiple administration of UDCA. This study is the first to confirm that the PK measurements of UDCA were higher in elderly subjects than in younger adults, which may improve the clinical outcomes of elderly subjects.

Cisplatin causes acute kidney injury (AKI) through proximal tubular injury. We investigated the protective effect of the adenosine monophosphate protein kinase (AMPK) activator 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) against cisplatin-induced AKI. We investigated whether the AMP-kinase activator AICAR ameliorates cisplatin-induced AKI through the JAK/STAT/SOCS pathway. Male Sprague-Dawley (SD) rats were randomly divided into four groups: control, AICAR, cisplatin, and cisplatin + AICAR. As appropriate to their treatment group, the rats were injected with a single dose of cisplatin (7 mg/kg, i.p.). AICAR was administered to the rats at 100 mg/kg i.p. daily. Blood urea nitrogen (BUN) and serum creatinine were measured. Renal damage was analyzed in sections stained with hematoxylin and eosin (H&E). Renal tissues were also examined by immunohistochemistry and western blot for p-AMPK, Kim-1, cleaved caspase 3, and JAK/STAT/SOCS. For in vitro studies, NRK-52E normal rat kidney cells were treated with cisplatin and/or AICAR. By western blot, we confirmed the expression of p-AMPK and the JAK/STAT/SOCS pathway in NRK-52E cells. AICAR was protective against cisplatin-induced acute tubular injury by up-regulating p-AMPK expression in NRK-52E cells. Protein expression levels of JAK2/STAT1 were markedly ameliorated in NRK-52E cells by AICAR. The protective mechanism of AICAR may be associated with suppression of the JAK2/STAT1 pathway and up-regulation of SOCS1, an inhibitor of the JAK2/STAT1 pathway. The present study demonstrates the protective effects of AICAR against cisplatin-induced AKI and shows a new renoprotective mechanism through the JAK2/STAT1/SOCS1 pathway and apoptosis inhibition. This study suggests that activation of the AMPK activator AICAR might ameliorate cisplatin-induced AKI.

Background: Concentrations of 6-thioguanine (6TG) nucleotides and 6-methylmercaptopurine (6MMP) nucleotides in RBCs were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). This assay was validated for clinical use and was applied to blood samples from patients taking mercaptopurine (6MP). Methods: RBCs were hemolyzed and deproteinized using perchloric acid, followed by heating for the hydrolysis of nucleotides, and the resultant base was measured using LC-MS/MS. Precision, recovery, linearity, matrix effect, and limit of quantification was validated for clinical application. Our results were compared with another institution's established LC-MS/MS assay. We measured the concentrations of 6TG and 6MMP in RBCs of pediatric patients with acute lymphoblastic leukemia (ALL), and the clinical impact of those metabolites was investigated. Results: The imprecision coefficient of variations of 6TG and 6MMP were 5.7%–8.1%, and the bias was within 5%. Lower limits of quantification were set at 54 ng/mL for 6TG and 1036 ng/mL for 6MMP. Correlation coefficients for 6TG and 6MMP were 0.997 and 1.0 in a comparison study. For clinical proof-of-concept, 74 blood samples were collected from 37 pediatric ALL patients receiving maintenance therapy. Concentration of 6TG ranged from 16.1 to 880 pmol/8 × 108 RBCs and that of 6MMP from 55 to 20,937 pmol/8 × 108 RBCs. The 6MP metabolites were not correlated with WBC or absolute neutrophil count. On the other hand, the higher 6MMP level was associated with elevated alanine aminotransferase and aspartate aminotransferase. Conclusions: In this study, an assay for the quantification of 6TG and 6MMP in RBCs was established and applied to pediatric ALL patients. Interindividual variability in 6MP metabolite concentrations was considerable and associated with elevation of liver enzymes, which may be useful in the clinical monitoring of 6MP maintenance therapy in pediatric ALL patients.

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.

This study aimed to develop a pharmacokinetic (PK) model of oxcarbazepine (OXC) and analyse the relationship between monohydroxylated derivative (MHD), an active metabolite of OXC, and the adverse events of OXC. We obtained 711 OXC samples from 618 patients with epilepsy who were enrolled in the Epilepsy Registry Cohort of Seoul National University Hospital from February 2011 to January 2014. The plasma PK model was developed using a nonlinear mixed-effect modelling method with NONMEM (ver 7.3). A one-compartment model with a first-order absorption model and proportional residual error adequately described the MHD concentration–time profiles. The only covariate incorporated for CL/F and V/F was body weight. Of the 447 patients analysed, 28 (6.26%) had dose-related adverse events (DRAEs), which were dizziness, somnolence, headache, and diplopia. For DRAE occurrence, the cut-off values of the MHD trough and AUC were 12.27 mg/L (specificity 0.570, sensitivity 0.643) and 698.5 mg h/L (specificity, sensitivity 0.571), respectively. Multivariate analysis showed the sole dizziness symptom was significantly associated with both the MHD trough and the AUC (p = 0.013, p = 0.038, respectively). We newly developed a population PK model using sparse sampling data from patients with epilepsy, and the model better reflects the actual clinical situation.

Eunsol Yang, Hyounggyoon Yoo, In-Jin Jang, Kyung-Sang Yu, SeungHwan Lee Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Republic of KoreaCorrespondence: SeungHwan LeeDepartment of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, 101 Daehak-Ro, Jongno-Gu, Seoul, 03080, Republic of KoreaTel +82-2-2072-2343Fax +82-2-742-9252Email leejh413@snu.ac.krPurpose: A fixed-dose combination (FDC) of gemigliptin/rosuvastatin 50/20 mg as a monolayer tablet has been used to treat patients with both type 2 diabetes mellitus and dyslipidemia. To improve the stability of the FDC, a new FDC formulation as a bilayer tablet was developed. This study aimed to compare the pharmacokinetics (PKs) and pharmacodynamics (PDs) of the FDC of gemigliptin/rosuvastatin 50/20 mg between the newly developed bilayer tablet and the approved monolayer tablet in healthy subjects.Materials and Methods: A randomized, open-label, single-dose, two-treatment, two-way crossover study was conducted. Subjects received a single dose of the FDC of gemigliptin/rosuvastatin 50/20 mg as the bilayer tablet or the monolayer tablet in each period with a 7-day washout. For PK and PD analyses, serial blood samples were collected up to 72 hours after dosing to determine plasma concentrations of gemigliptin, its active metabolite LC15-0636 and rosuvastatin, and plasma dipeptidyl peptidase-4 (DPP-4) activity. PK and PD parameters were calculated using non-compartmental methods and compared between the two formulations.Results: A total of 48 healthy subjects were randomized, and 45 subjects completed the study. The concentration–time profiles of gemigliptin, LC15-0636 and rosuvastatin were comparable between the two formulations. All geometric mean ratios (90% confidence intervals) of the bilayer tablet to the monolayer tablet for maximum plasma concentration and area under concentration–time curve from 0 to last measurable time point of the three compounds fulfilled the bioequivalence criteria of 0.80– 1.25. Likewise, area under plasma DPP-4 activity inhibition from baseline-time curve from 0 to last measurable time point and maximum inhibition of plasma DPP-4 activity were similar between the two formulations.Conclusion: The FDC of gemigliptin/rosuvastatin 50/20 mg as the bilayer tablet showed equivalent PK and PD properties with the FDC of gemigliptin/rosuvastatin 50/20 mg as the monolayer tablet in healthy subjects. These results suggest that the newly developed bilayer tablet can become an alternative formulation to the commercially available monolayer tablet.Keywords: DPP-4 inhibitor, statin, type 2 diabetes, dyslipidemia, bioequivalence

Isoniazid is a therapeutic agent for the treatment of latent tuberculosis infection. Genetic variants in the N-acetyltransferase 2 (NAT2) are associated with the safety and pharmacokinetics of isoniazid. The study aimed to evaluate the safety and pharmacokinetics of a NAT2 genotype-guided regimen of isoniazid monotherapy. A randomized, open-label, parallel-group and multiple-dosing study was performed in healthy subjects. The subjects received isoniazid for 29 days. The NAT2 slow acetylators (NAT2*5/*5, -*5/*6, -*5/*7, -*6/*6, -*6/*7, -*7/*7) randomly received standard dose (300 mg, standard-treatment group) or reduced dose (200 mg, PGx-treatment group) of isoniazid. Also, all the NAT2 rapid acetylators (NAT2*4/*4) received isoniazid 300 mg (reference group). The safety and pharmacokinetics were evaluated during the study. The PGx-treatment group showed a more stable serum liver enzyme profile and a lower incidence of adverse drug reactions (ADRs) than the standard-treatment group. The emergence rates of ADRs were 12.5, 60 and 33.3% in the reference, standard-treatment and PGx-treatment groups, respectively. The PGx-treatment group showed higher plasma isoniazid concentrations than the reference group, although the PGx-treatment group received a reduced dose of isoniazid. Our results showed that a NAT2 genotype-guided regimen may reduce ADRs during isoniazid monotherapy without concern over insufficient drug exposure.

Purpose Ranolazine, an inhibitor of late inward sodium current, is an antianginal agent. In this study, the pharmacokinetic (PK) properties and tolerability of single- and multiple-dose ranolazine were compared between healthy Korean and white subjects. Methods An open-label, ascending single- and multiple-dose study was conducted with healthy male Korean and white subjects. Subjects were administered 375–750 mg of ranolazine once in a single-dose and twice daily in multiple-dose based on their dose groups. Blood samples for the PK assessment were collected up to 48 h after dosing. The geometric mean ratio and its 90% confidence interval in Korean to white subjects for Cmax, Cmax,ss, AUClast, and AUC0–12h,ss of ranolazine were calculated. A population PK analysis was also performed. Safety profiles were assessed throughout the study. Findings A total of 70 Korean and 48 white subjects completed the study. Ranolazine exposure was similar between Korean and white subjects in all dose groups; however, ranolazine exposure at 750 mg was observed to increase by up to 29% in Korean subjects compared with that in white subjects. On the basis of previous studies, these differences in ranolazine exposure between the 2 ethnic groups may not result in any clinically significant difference. Furthermore, ethnicity was not significantly correlated with the PK properties of ranolazine in the ranolazine PK model. In addition, no significant difference was found in the safety profile of ranolazine between the 2 ethnic groups. Implications The PK properties of ranolazine had no clinically significant difference, and no difference was found in the safety profiles of ranolazine between Korean and white subjects. It is anticipated that ranolazine can be administered in Korean subjects without dose adjustment. ClinicalTrials.gov identifier: NCT02817932.

Sulfonylurea (SU) and dipeptidyl peptidase-4 (DPP-4) inhibitors are most common secondary agents that are added to metformin monotherapy. Real-world studies have become increasingly important in providing evidence of treatment effectiveness in clinical practice and real-world data could help appropriate therapeutic information. Therefore, this study aims to compare the glycemic effectiveness of SU and DPP-4 inhibitors, which are added to metformin monotherapy in real clinical practice using electronic medical record (EMR) data. EMR data of type 2 diabetes patients treated at Seoul National University Hospital from December 2002 to December 2012 were retrieved and analyzed. The patients were divided into three groups: patients who maintained metformin monotherapy (M), and patients who added SU (MS) or DPP-4 inhibitors (MD) to metformin monotherapy. The mean change in HbA1c level, the proportion of patients achieving the HbA1c target < 7.0%, proportion of patients with treatment failure, and probability of treatment failure occurrence and changes in prescription were evaluated to compare glycemic control efficacy between SU and DPP-4 inhibitors. The MS showed significantly greater reduction in the Hb1Ac level than MD. The proportion of patients achieving HbA1c < 7.0% is higher in MD, whereas the proportion of patients with treatment failure was greater in MS. The probability of the treatment failure and probability of changes in the prescription were lower in MD than MS with hazard ratio of 0.499 and 0.579, respectively. In conclusion, this real-world study suggested that DPP-4 inhibitors are expected to show more durable glycemic control efficacy than SU in long-term use.

Cytochrome P450 (CYP) 3A-related drug-drug interaction (DDI) studies are needed during drug development to determine clinical interaction effects. We aimed to evaluate DDI between sildenafil and two CYP3A inhibitors, clarithromycin and itraconazole, regarding the changes in pharmacokinetics and endogenous markers. An open-label, one-sequence, one-period, two-treatment parallel study was conducted in 32 healthy Korean subjects. Each of 16 subjects were randomly assigned to the clarithromycin and itraconazole groups. Both groups received a single dose of sildenafil 25 mg as a control, and either clarithromycin 250 mg or itraconazole 100 mg was administered four times to inhibit CYP3A activity. Pharmacokinetics of sildenafil showed the similar magnitude of inhibitory effects of the two inhibitors on total CYP3A activity; both inhibitors similarly increased systemic exposure of sildenafil by 2-fold. Urinary 6β–OH–cortisone/cortisone and plasma 4β–OH–cholesterol were significantly decreased after clarithromycin administration but not after itraconazole. A significant correlation between sildenafil CL/F and metabolic markers of CYP3A activity was observed after clarithromycin administration. We confirmed that sildenafil has moderate pharmacokinetic interaction with clarithromycin and itraconazole. Endogenous markers well reflected the CYP3A inhibition of clarithromycin, suggesting possible utility in DDI study with moderate to strong CYP3A inhibition; however, there are limitations in predicting intestinal CYP3A mediated DDI.

Background The number of clinical trials conducted in Korea continues to increase and an increasing proportion focus on severe and rare incurable diseases. After the start of the severe acute respiratory syndrome, coronavirus disease 2019 (COVID-19), Korea Centers for Disease Control and Prevention (KCDC) developed guidelines to prevent the spread of infection. This study evaluated the impact of COVID-19 and the KCDC guideline on the conduct of clinical research in Korea. The purpose was to develop recommendations on how to minimize the risk of infection while enabling subjects to take part in the trials if no better alternative treatment options were available. Methods The impact on subject's scheduled visits and major milestones of clinical trials in Korea were measured by conducting a survey among clinical project manager (CPMs) working at global clinical research organization. The policy on monitor's access to hospital and site initiation meetings was investigated through correspondence with clinical trial center of 39 hospitals. The Top 25 pharmaceutical companies' official press and public clinical trial registry database were used to analyze companies' trial strategy during the pandemic and COVID-19 clinical research status, respectively. Results Of 85 CPMs, 12% reported that trial subjects' scheduled visits had been affected in their project. Monitors' access to hospital for source data verification was restricted at all sites in February 2020. Accordingly, 43% of 105 CPMs reported that the COVID-19 epidemic had an effect on study major milestones and data cleaning and database lock accounted for > 60% of milestones affected. In addition, 87% sites advised not to have site initiation meetings and 52% pharmaceutical companies suspended recruitment or new study start-up due to the pandemic. On the other hands, the number of COVID-19 related clinical trials increased rapidly in Korea and worldwide, with investigator-initiated trials accounting for 47% and 63% of all trials locally and globally, respectively. Most trials were phase 2 and were in the recruitment stage. Conclusion The COVID-19 and the KCDC guideline influenced all parties involved in clinical trials in Korea. In order to ensure the safety and well-being of trial subjects during the pandemic, new approaches are required for clinical trials to respond to the impact actively. Method of non-contact is developed to replace and supplement the face-to-face contact and alternatives to reduce the travel is introduced to decrease the risk of infection for all trial participants in whole trial process. The relevant regulations should be developed and the guidelines for foreign countries need to be adopted in accordance with the situation in Korea. COVID-19 trial is rapidly increasing worldwide and continuous support of health authorities, regulation, and facilities is required for developing the treatments with protecting all trial participants., Graphical Abstract

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.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.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 be5%. All reported drug-related adverse events were injection-site reactions, and no serious adverse events were reported.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.

Jun Gi Hwang, Kyung-Sang Yu, SeungHwan Lee Department of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, Seoul, Republic of KoreaCorrespondence: SeungHwan LeeDepartment of Clinical Pharmacology and Therapeutics, Seoul National University College of Medicine and Hospital, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of KoreaTel +82 2 2072 19200Fax +82 2 742 9252Email ksyu@snu.ac.krPurpose: A fixed-dose combination (FDC) of fimasartan and atorvastatin is used to treat hypertension and dyslipidemia. The peak plasma concentration (Cmax) of fimasartan and atorvastatin has a large intra-subject variability with a maximum coefficient of variation of 65% and 48%, respectively. Therefore, both drugs are classified as highly variable drugs. The purpose of this study was to compare the pharmacokinetics (PK) between a FDC of fimasartan 120 mg and atorvastatin 40 mg versus separate tablets in healthy male Korean subjects.Subjects and Methods: A randomized, single-dose, two-treatment, three-sequence, three-period, partial replicated crossover study was conducted with a 7-day washout interval between periods. Blood samples for fimasartan and atorvastatin were collected until 48 hours after administration in each period. PK parameters were calculated using the non-compartmental method. Geometric mean ratios (GMRs) for PK parameters of FDC to loose combination and their 90% confidence intervals (90% CIs) were estimated.Results: A total of 56 subjects completed the study. GMRs (90% CIs) of the Cmax for fimasartan and atorvastatin were 1.08 (0.93– 1.24) and 1.02 (0.92– 1.13), respectively. The expanded 90% CIs of both drugs using the intra-subject variability was calculated range of 0.70– 1.43 and 0.73– 1.38, respectively. The corresponding values of area under the concentration–time curve from zero to the last measurable time point were 1.02 (0.97– 1.08) and 1.02 (0.98– 1.07), respectively.Conclusion: FDC of fimasartan 120 mg and atorvastatin 40 mg between their loose combination showed similar PK characteristics.Keywords: fixed-dose combination, partial replicated design, fimasartan, atorvastatin, pharmacokinetics