Yo Han Kim

Effects of Ketoconazole and Rifampicin on the Pharmacokinetics of Gemigliptin, a Dipeptidyl Peptidase-IV Inhibitor: A Crossover Drug-Drug Interaction Study in Healthy Male Korean Volunteers

BACKGROUNDnGemigliptin (LC15-0444) is a newly developed selective and competitive inhibitor of dipeptidyl peptidase (DPP)-4 and has potential for the treatment of type 2 diabetes mellitus. Gemigliptin is metabolized by the cytochrome P450 (CYP) 3A4 isozyme to yield the active major metabolite LC15-0636.nnnOBJECTIVEnThe effects of multiple oral doses of ketoconazole (a potent CYP3A4 inhibitor) and multiple oral doses of rifampicin (a potent CYP3A4 inducer) on the pharmacokinetic properties of a single oral dose of gemigliptin were evaluated in fasting healthy male Korean volunteers.nnnMETHODSnIn this open-label, 2-part, 3-treatment, 1-sequence, 2-period crossover drug-drug interaction study, 1 group of subjects received a single 50-mg oral dose of gemigliptin on 2 separate occasions-once as monotherapy and again after pretreatment with 400 mg of oral ketoconazole once daily for 7 days. The other group of subjects received a single 50-mg oral dose of gemigliptin on 2 separate occasions-once without pretreatment and again after pretreatment with 600 mg of oral rifampicin once daily for 10 days. Blood samples were obtained at 0 (predose), 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 12, 24, 48, and 72 hours after gemigliptin dosing. Plasma concentrations were determined using LC-MS/MS. Pharmacokinetic parameters were estimated via noncompartmental methods. Tolerability was assessed using measurements of vital signs, clinical chemistry tests, and interviews.nnnRESULTSnTwenty-four subjects were enrolled (12 per group). Concurrent administration of ketoconazole was associated with increased total gemigliptin plasma exposure (AUC(0-∞); 2.36-fold [90% CI, 2.19-2.54]) and decreased metabolism of gemigliptin until negligible concentrations of LC15-0636 were detected. Pretreatment with rifampicin was associated with decreased AUC(0-∞) of gemigliptin (by 80% [90% CI, 78%-82%]) and a 2.9-fold increase (mean [SD], 0.18 [0.08] to 0.52 [0.10]) in the metabolic ratio of gemigliptin to LC15-0636. The treatments were well-tolerated, with no severe adverse events reported. Six of the 24 subjects (25%) experienced AEs during the first period of gemigliptin monotherapy administration. Six of 12 subjects (50%) each experienced AEs during concurrent administration with ketoconazole and rifampicin.nnnCONCLUSIONSnIn this select group of healthy male Korean volunteers, concurrent administration of gemigliptin with ketoconazole or rifampicin was associated with significantly increased or decreased systemic exposure to gemigliptin, respectively. These findings suggest that gemigliptin may require a dose adjustment when concurrently administered with drugs that alter CYP3A4 activity. Concurrent administration of gemigliptin with ketoconazole or rifampicin was well tolerated. ClinicalTrials.gov identifier: NCT01426906.

Bioavailability and tolerability of combination treatment with revaprazan 200 mg + itopride 150 mg: a randomized crossover study in healthy male Korean volunteers.

BACKGROUNDnTo date, no definitive treatment of functional dyspepsia (FD) has been proven to be effective and reasonably well-tolerated. Proton pump inhibitors (PPIs) combined with prokinetic agents are considered an effective option. Revaprazan is a selective potassium-competitive acid blocker that reversibly inhibits gastric H(+)/K(+)-ATPase and shows effective acid suppression comparable to PPIs. Itopride is a prokinetic agent that has anticholinesterase activity as well as dopamine D(2) receptor antagonistic activity. For this reason, revaprazan and itopride have been prescribed for FD; however, no available studies have reported the pharmacokinetic interactions of these 2 drugs.nnnOBJECTIVEnThe objective of this study was to compare the bioavailability and tolerability of revaprazan and itopride combination therapy to those of equally dosed monotherapies to acquire basic drug-drug interaction information about revaprazan.nnnMETHODSnThis multiple-dose, randomized crossover study was conducted in healthy male Korean subjects. Subjects received, in randomized sequence, a 7-day oral dose of revaprazan 200 mg once daily, itopride 50 mg TID, or both. Each treatment period was separated by a 7-day washout period. Blood samples were collected for up to 24 hours following the last dose at steady state, and drug concentrations were determined using validated LC/MS-MS. Pharmacokinetic properties were obtained using noncompartmental analysis. Drug tolerability was assessed throughout the study, using measurements of vital signs, clinical chemistry testing, and interviews.nnnRESULTSnA total of 30 subjects were enrolled in the study. Among them, 28 subjects completed revaprazan treatment, and 27 completed the study (3 subjects were withdrawn). The geometric mean ratios (GMRs) (90% CI) of C(max,ss), and AUC(τ,ss) with revaprazan were 0.92 (0.84-1.00) and 0.96 (0.89-1.03), respectively. The GMRs of C(max,ss) and AUC(τ,ss) with itopride were 1.07 (0.96-1.20) and 1.12 (1.06-1.18), respectively. A total of 15 adverse events (AEs) were reported in 8 subjects. All AEs were considered to be mild, and there were no clinically significant differences between treatment groups.nnnCONCLUSIONnThe findings from this study suggest bioequivalence between revaprazan given as monotherapy and in combination with itopride in these healthy Korean male volunteers, with no clinical significant drug-drug interaction. All treatments in this study was generally well tolerated. ClinicalTrials.gov identifier: NCT0133289.

Pharmacokinetic Interaction of Telmisartan With S-Amlodipine: An Open-Label, Two-Period Crossover Study in Healthy Korean Male Volunteers

BACKGROUNDnTelmisartan belongs to a class of orally active angiotensin II receptor blockers (ARBs), and S-amlodipine is an enantiomer of amlodipine. Amlodipine is a racemic mixture and the calcium channel blocking (CCB) effect is confined to S-amlodipine, whereas R-amlodipine has a 1000-fold lower activity and no racemization occurs in vivo in human plasma. Combination therapy of ARBs with CCBs provides advantages for blood pressure control and vascular protection over monotherapy.nnnOBJECTIVEnTo investigate the effects of coadministration of telmisartan and S-amlodipine on the steady-state pharmacokinetic properties of each drug as a drug-drug interaction study required before developing the fixed-dose combination agent.nnnMETHODSnThis study comprised 2 separate parts, A and B; each was a multiple-dose, open-label, 2-sequence, 2-period, crossover study in healthy male Korean volunteers. In part A, volunteers were administered 80 mg of telmisartan, either alone or with 5 mg of S-amlodipine. In part B, volunteers were administered 5 mg of S-amlodipine, either alone or with 80 mg of telmisartan. Blood samples were taken on days 9 and 37, following the final dose of each treatment, and at 0 (predose), 0.5, 1, 1.5, 2, 3, 4, 5, 6, 8, 10, 12, and 24 hours after administration in part A, and were taken at 0 (predose), 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, and 24 hours after administration in part B. Plasma concentrations were determined using LC-MS/MS. The pharmacokinetic properties of each drug after coadministration of telmisartan and S-amlodipine were compared with those of each drug administered alone. Tolerability was assessed using measurements of vital signs, clinical chemistry tests, and interviews.nnnRESULTSnFifty-six volunteers were enrolled (32 in part A and 24 in part B), and all completed except 4 volunteers (3 withdrawn in part A and 1 withdrawn in part B). The geometric mean ratios (GMRs) (90% CI) for the C(max,ss) and AUC(τ,ss) of telmisartan (with or without S-amlodipine) were 1.039 (0.881-1.226) and 1.003 (0.926-1.087), respectively. The GMRs (90% CI) for C(max,ss) and AUC(τ,ss) of S-amlodipine (with or without telmisartan) were 0.973 (0.880-1.076) and 0.987 (0.897-1.085). Total 11 adverse events (AEs) were reported in 7 volunteers (21.9%) in part A. A total of 9 AEs were reported in 6 volunteers (25.0%) in part B. Statistical analysis confirmed that the 90% CIs for these pharmacokinetic parameters were within the commonly accepted bioequivalence range of 0.8 to 1.25, indicating that the extent of bioavailability of S-amlodipine was not affected by telmisartan. The intensity of all AEs was considered to be mild, and there were no significant differences in the prevalences of AEs between the 2 formulations.nnnCONCLUSIONSnFollowing multiple-dose coadministration of high doses of telmisartan and S-amlodipine, the steady-state pharmacokinetic properties of telmisartan were not significantly affected, and telmisartan had no significant effect on the pharmacokinetic properties of S-amlodipine at steady state in these selected groups of healthy volunteers. Both formulations were generally well-tolerated.

Therapeutic dosage assessment based on population pharmacokinetics of a novel single-dose transdermal donepezil patch in healthy volunteers

PurposeWe performed population pharmacokinetic (PK) analysis of a novel transdermal donepezil patch in healthy subjects who participated in a phase I trial. We also studied the optimal dosage regimen with repeated patch application for achieving a therapeutic range using a PK simulation model.MethodsThis study used data from a randomized, single-dose escalation phase I clinical trial conducted in Korea. The population PK analysis was performed using NONMEM software, version 7.3. From the final PK model, we simulated repeat patch application results assuming various transdermal absorption rates.ResultsBased on the clinical trial data, novel donepezil patches with doses of 43.75xa0mg/12.5xa0cm2, 87.5xa0mg/25xa0cm2, and 175xa0mg/50xa0cm2 were placed on each subject. A linear one-compartment, first-order elimination with sequential zero- and first-order absorption model best described the donepezil plasma concentrations after patch application. Simulated results on the basis of the PK model showed that repeat application of the patches of 87.5xa0mg/25xa0cm2 and 175xa0mg/50xa0cm2 every 72xa0h would cover the therapeutic range of donepezil and reach steady-state faster with fewer fluctuations in concentration compared to typical oral administrations.ConclusionA linear one-compartment with sequential zero- and first-order absorption model was effective for describing the PKs of donepezil after application of patch. Based on this analysis, 87.5xa0mg/25xa0cm2 or 175xa0mg/50xa0cm2 patch application every 72xa0h is expected to achieve the desired plasma concentration of donepezil.

Tolerability and Pharmacokinetics of Two Formulations of Megestrol Acetate under Fed Conditions in Healthy Volunteers

PURPOSEnMegestrol acetate oral suspension is an appetite stimulant indicated for cachexia. It is available in a conventional formulation and as a nanocrystal dispersion. The aim of this study was to compare the tolerability and pharmacokinetics of these formulations under fed conditions in healthy Korean volunteers.nnnMETHODSnThis was a randomized, single-dose, 3-treatment, 3-period, 6-sequence, crossover study in healthy Korean volunteers. In each period, participants received single oral doses of conventional formulation 800 mg/20 mL (reference), nanocrystal dispersion 650 mg/5.2 mL (test 1), and nanocrystal dispersion 675 mg/5.4 mL (test 2) after a high-calorie, high-fat meal. The periods were separated by a washout period of 14 days. Serial blood samples were collected up to 120 hours after dosing. The plasma concentrations of megestrol acetate were determined with a validated LC-MS/MS method. Pharmacokinetic parameters were obtained by noncompartmental analysis. Tolerability was assessed by physical examinations, vital signs, clinical laboratory test results, and electrocardiograms.nnnFINDINGSnThirty-eight healthy volunteers completed the study. The geometric mean ratios of the AUC(last) and C(max) for test 1/reference were 0.88 (90% CI, 0.84-0.92) and 1.07 (90% CI, 0.99-1.15), respectively. The geometric mean ratios of the AUC(last) and C(max) for test 2/reference were 0.88 (90% CI, 0.84-0.93) and1.03 (90% CI, 0.96-1.10), respectively. All formulations were well tolerated.nnnIMPLICATIONSnThe pharmacokinetic characteristics and tolerability of the 2 megestrol acetate formulations are similar in fed volunteers and suggest no relevant difference in tolerability. ClinicalTrials.gov identifier: NCT01342055.

Pharmacokinetic, Pharmacodynamic, and Safety/Tolerability Profiles of CG100649, a Novel COX-2 Inhibitor: Results of a Phase I, Randomized, Multiple-dose Study in Healthy Korean Men and Women

BACKGROUNDnCG100649 is a novel anti-inflammatory drug that is currently under development. CG100649 demonstrates a dual mechanism of action on cyclooxygenase-2 and carbonic anhydrase that may result in favorable treatment effects and few adverse gastrointestinal and cardiovascular events.nnnOBJECTIVEnThe objective of this study was to evaluate the safety, pharmacokinetic, and pharmacodynamic profiles of administering multiple oral doses of CG100649 to healthy Korean volunteers.nnnMETHODSnThis was a randomized, double-blind, placebo-controlled, multiple ascending oral dose study that was performed on 8 male and 8 female subjects per dose cohort. Each subject was randomly selected to receive either a single loading dose followed by 6 days of once-daily placebo (n = 4; 2 male and 2 female subjects) or CG100649 (n = 12; 6 male and 6 female subjects). Each subject was administered 1 of 3 sequential dose levels (8-mg loading dose + 2 mg/d, 10-mg loading dose + 4 mg/d, or 12-mg loading dose + 8 mg/d). Blood samples for pharmacokinetic analysis were obtained ≤480 hours after the last dose. Blood samples for measuring serum thromboxane B2 (TXB2) and ex vivo lipopolysaccharide-stimulated prostaglandin E2 (PGE2) (markers of cyclooxygenase-1 and cyclooxygenase-2 activity, respectively) and urine samples for measuring prostanoid metabolites were collected ≤21 days after the last dose.nnnRESULTSnDuring steady state, the median Tmax in blood and plasma after the last dose ranged from 3 to 10 hours and 3.5 to 7.3 hours, respectively. Mean terminal t½ values in blood and plasma ranged from 121 to 203 hours and 100 to 167 hours, respectively. Whole blood concentrations were 50 to 70 times higher than plasma concentrations in all 3 dose cohorts in both male and female subjects. Compared with baseline, serum TXB2 diminished by 68% to 91% at 8 hours after the administration of the last dose in all 3 cohorts (P < 0.001). Ex vivo lipopolysaccharide-stimulated PGE2 was maximally inhibited (89%-96%; P < 0.001) by all 3 dose levels on day 7. Urinary prostacyclin metabolite was inhibited by 64% (P < 0.001) on day 7 (12-24 hours) but only by the highest CG100649 dose. There were no clinically significant drug-related changes in blood pressure between treatment groups. The most frequently encountered adverse events were aphthous stomatitis and dyspepsia.nnnCONCLUSIONSnCG100649 was well tolerated and demonstrated a whole blood concentration that is ~50 to 70 times higher than in plasma in these healthy subjects. CG100649 suppressed TXB2 and PGE2 at all 3 doses, and only the highest dose suppressed the urinary excretion of the urinary prostacyclin metabolite.

Pharmacokinetics, Tolerability, and Safety of the Single Oral Administration of AGSAV301 vs Exforge: A Randomized Crossover Study of Healthy Male Volunteers

Background and ObjectiveValsartan, an angiotensin receptor blocker, is often used with calcium channel blockers (CCBs) such as amlodipine to control hypertension. Recently, the fixed-dose combination (FDC) of amlodipine 10xa0mg/valsartan 160xa0mg (Exforge) was approved. Amlodipine is a racemic mixture of CCB; S-amlodipine has higher activity than R-form. Therefore, AGSAV301, the FDC of S-amlodipine 5xa0mg/valsartan 160xa0mg was recently developed. The objective of this study was to compare the pharmacokinetic (PK) characteristics of S-amlodipine and valsartan when administered as one tablet each of Exforge and AGSAV301 to healthy male subjects.MethodsThis was a single-dose, randomized, open-label, two-way, two-period crossover study. Each subject received a single dose of AGSAV301 and Exforge, separated by a 3-week washout period. Plasma samples for the PK analysis of valsartan and S-amlodipine were collected at predose (0) and 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 16, 24, 36, 48, 72, 96, 120, and 168xa0h after administration. Tolerability was also evaluated.ResultsA total of 29 subjects were enrolled; 24 completed this study. The S-amlodipine maximum plasma concentration (Cmax) geometric mean ratio (GMR) between AGSAV301 and Exforge was 0.951 (90xa0% CI 0.983–1.014), and area under the concentration–time curve from time 0 to last measured time point (AUClast) was 0.917 (90xa0% CI 0.861–0.976). The GMR of valsartan Cmax was 0.994 (90xa0% CI 0.918–1.076), and the AUClast was 0.927 (90xa0% CI 0.821–1.047). All adverse events (AEs) were resolved without sequelae; no serious AEs were reported. Two drugs showed similar tendencies to lower blood pressure in healthy subjects.ConclusionsThe PK profiles of AGSAV301 and Exforge were bioequivalent. Both drugs were also well tolerated, with comparable AE profiles and similar blood pressure-lowering tendencies in healthy volunteers, suggesting equivalent therapeutic indications.