Ethnic or Racial Differences Revisited

Cariprazine in the acute treatment of unipolar and bipolar depression: A systematic review and meta-analysis

BACKGROUND

Cariprazine has emerged as a promising augmenting treatment agent for unipolar depression and as a monotherapy option for bipolar depression. We evaluated cariprazine's efficacy in treating acute major depressive episodes in individuals with major depressive disorder (MDD) or bipolar disorder.

METHODS

A systematic review was conducted on MEDLINE, Embase, PsycINFO, Scopus and Web of Science, ClinicalTrials.gov and ScanMedicine. Study quality was assessed using the RoB 2 tool. Pairwise and dose-response meta-analyses were conducted with RStudio. Evidence quality was assessed with GRADE.

RESULTS

Nine RCTs meeting inclusion criteria encompassed 4889 participants. Cariprazine, compared to placebo, significantly reduced the MADRS score (MD = -1.49, 95 % CI: -2.22 to -0.76) and demonstrated significantly higher response (RR = 1.21, 95 % CI: 1.12 to 1.30) and remission (RR = 1.19, 95 % CI: 1.06 to 1.34) rates. Subgroup analysis unveiled statistically significant reductions in MADRS score in MDD (MD = -1.15, 95 % CI: -2.04 to -0.26) and bipolar I disorder (BDI) (MD = -2.53, 95 % CI: -3.61 to -1.45), higher response rates for both MDD (RR = 1.19, 95 % CI: 1.08 to 1.31) and BDI (RR = 1.27, 95 % CI: 1.10 to 1.46), and higher remission rates only for BDI (RR = 1.41, 95 % CI: 1.24 to 1.60). A higher rate of treatment discontinuation due to adverse events was observed.

LIMITATIONS

Reliance solely on RCTs limits generalisability; strict criteria might not reflect real-world diversity.

CONCLUSIONS

Cariprazine demonstrates efficacy in treating major depressive episodes, although variations exist between MDD and BDI and tolerability may be an issue.

Evaluation of pharmacokinetic pharmacodynamic target attainment of meropenem in pediatric patients

BACKGROUND

Meropenem is a widely used carbapenem for treating severe pediatric infections. However, few studies have assessed its pharmacokinetics/pharmacodynamics (PK/PD) in pediatric patients. This study aimed to evaluate the proportion of Saudi pediatric patients achieving the PK/PD target of meropenem.

METHODS

A prospective observational study was conducted at King Saud University Medical City from July to September 2022. Pediatric patients receiving meropenem for suspected or proven infections were included in the study. The primary outcome was the percentage of patients achieving the recommended PK/PD target for critically ill or non-critically ill pediatric patients.

RESULTS

The study included 30 patients (nine neonates and 21 older pediatric patients). All neonates were critically ill. Among them, 55 % achieved the PK/PD target of 100 % free time above the MIC. In older ICU pediatric patients, only 11 % attained this target, whereas 58 % of older pediatrics in the general wards achieved the PK/PD target of 50 % free time above the MIC. Augmented renal clearance (ARC) was identified in 57 % of our pediatric patient population, none of whom achieved the recommended PK/PD targets. The median trough concentrations in patients with and without ARC were 0.75 and 1.3 μg/mL, respectively (P < 0.05).

CONCLUSIONS

The majority of patients in our cohort did not achieve the PK/PD target for meropenem. ARC emerged as a major risk factor for target attainment failure in both critically ill and non-critically ill pediatric patients.

Gender, racial, ethnic, and Fitzpatrick skin type representation in Acanthosis nigricans clinical trials

Acanthosis nigricans (AN) is characterized by dark, velvety patches and thin plaques primarily in the body folds. AN is more prevalent in skin of color populations, including Black/African American, Native American, and Hispanic patients. As the U.S. population becomes increasingly diverse, the need for inclusive dermatologic research becomes more pressing. Given the increased prevalence of AN in skin of color patients, there is a need to evaluate representation in AN clinical trials. This study aims to uncover gender, race, ethnicity, and Fitzpatrick skin type (FST) representation in AN clinical trials. A systematic literature search was performed across PubMed, Embase, and Cochrane databases to identify participant characteristics in clinical trials focused on AN treatment. Our review yielded 21 clinical trials, totaling 575 participants, with an identified predominance of female participants (69.0%) and a surprising absence of race or ethnicity data. Out of the 11 studies that included FST data, 1.2% of participants were type II, 20.6% were type III, 50.0% were type IV, and 28.2% were type V. None of the participants were FST I or VI. Herein, we highlight a predominate inclusion of female and FST III-V patients in AN clinical trials, the populations most impacted by this condition. We also highlight the need for improved race and ethnicity reporting and the importance of including all FSTs in clinical studies. Addressing this gap is critical for developing safe, efficacious, patient-centered, and equitable treatments for all AN patients. Future research should prioritize comprehensive inclusion of race, ethnicity, and the full spectrum of FSTs.

A Phase 1 Study of Ensitrelvir Fumaric Acid Tablets Evaluating the Safety, Pharmacokinetics and Food Effect in Healthy Adult Populations

BACKGROUND

A reported clinical pharmacokinetics and safety study of suspension formulation of ensitrelvir, a therapeutic agent used in severe acute respiratory syndrome coronavirus 2 infection, demonstrated favorable pharmacokinetics and was well tolerated in healthy male Japanese and White participants. Understanding the safety and pharmacokinetic features of ensitrelvir (using the formulation approved for clinical use) in various populations, and the effect of food, is crucial for optimal clinical use.

OBJECTIVES

The objectives of this study were to (1) assess the safety, tolerability, and pharmacokinetics of ensitrelvir following multiple-dose administration of ensitrelvir tablets in populations with different races, ages, and sex; and (2) assess the effect of food on the pharmacokinetics of ensitrelvir tablets in the fasted or fed state.

METHODS

A phase 1, multicenter, double-blinded, randomized, placebo-controlled study was conducted to evaluate the safety and pharmacokinetics of once-daily ensitrelvir tablets at loading/maintenance doses of 375/125 mg or 750/250 mg for 5 days in healthy Japanese females, Japanese elderly (only 375/125 mg), and White male and female participants. An open-label, two-group, two-period crossover study was also conducted to estimate the effect of food on the pharmacokinetics of ensitrelvir at single dose of 375 mg. The nature, frequency, and severity of treatment-emergent adverse events were evaluated and recorded in safety assessments in both studies.

RESULTS

The maximum plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC) were similar within these populations. The geometric mean half-life of ensitrelvir following multiple-dose administration was 48.7-58.9 h across all cohorts. The Cmax and AUC increased in a dose-proportional manner in Japanese female participants, and increased in a less than dose-proportional manner in White participants. Furthermore, there was no clear relationship between the dose and geometric mean half-life of ensitrelvir. The plasma concentration at 24 h (C24) after an initial dose of 375/125 mg exceeded the target plasma concentration (6.09 µg/mL) in all populations. Regarding the effect of food on the pharmacokinetics of ensitrelvir, although time to Cmax in the fed state was delayed, there was no clinically meaningful difference in the exposure levels (Cmax and AUC) of ensitrelvir between the fasted and fed states. Most treatment-emergent adverse events were mild in nature and had resolved.

CONCLUSION

Ensitrelvir (375/125 mg and 750/250 mg tablet formulation) was well tolerated, without any major safety concerns. The pharmacokinetics of ensitrelvir between all populations in the study were similar and C24 exceeded the target plasma concentration at 375/125 mg. These results suggest that ensitrelvir can be effectively administered with no necessity for dose adjustment for age, sex, and race without food restriction.

CLINICAL TRIAL REGISTRATION

Japan Registry of Clinical Trials identifier: jRCT2031210202, registered on 16 July 2021.

The frequency and duration of side-effects associated with the use of oral metronidazole; A prospective study of VITA trial participants

BACKGROUND

The tolerability of metronidazole is often perceived as being poor and in particular as being a cause of gastrointestinal side effects, but the frequency, severity and duration of adverse effects (AE) is not well characterised. This study assessed the frequency and type of metronidazole associated AEs in women treated for bacterial vaginosis.

METHODS

An exploratory study of participants from the lactic acid gel versus metronidazole for treating bacterial vaginosis (VITA) randomised controlled trial. In this sub-study, women aged ≥16 years, diagnosed with bacterial vaginosis and who received oral MTZ (400 mg twice daily, for 7 days) were followed up prospectively over 2 weeks. Baseline demographic and clinical data, and self-reported data on the incidence, time to onset, and duration of AEs were analysed.

RESULTS

155 women were included, of whom 64% (99/155) reported at least one metronidazole AE, including 47% (72/155) who reported gastrointestinal symptoms (nausea and/or vomiting [52/155], abdominal pain [31/154] or diarrhoea [31/154]) mostly within 3 days of starting treatment and resolving within 5 days of onset. Treatment discontinuation occurred in 8% (12/148) overall and AEs were given as the reason for discontinuing in only 3% (4/148).

CONCLUSION

Overall, metronidazole side effects occurred commonly, but resolved within a few days and had a limited impact on treatment completion.

Race, Ethnicity, and Pharmacogenomic Variation in the United States and the United Kingdom

The relevance of race and ethnicity to genetics and medicine has long been a matter of debate. An emerging consensus holds that race and ethnicity are social constructs and thus poor proxies for genetic diversity. The goal of this study was to evaluate the relationship between race, ethnicity, and clinically relevant pharmacogenomic variation in cosmopolitan populations. We studied racially and ethnically diverse cohorts of 65,120 participants from the United States All of Us Research Program (All of Us) and 31,396 participants from the United Kingdom Biobank (UKB). Genome-wide patterns of pharmacogenomic variation-6311 drug response-associated variants for All of Us and 5966 variants for UKB-were analyzed with machine learning classifiers to predict participants' self-identified race and ethnicity. Pharmacogenomic variation predicts race/ethnicity with averages of 92.1% accuracy for All of Us and 94.3% accuracy for UKB. Group-specific prediction accuracies range from 99.0% for the White group in UKB to 92.9% for the Hispanic group in All of Us. Prediction accuracies are substantially lower for individuals who identified with more than one group in All of Us (16.7%) or as Mixed in UKB (70.7%). There are numerous individual pharmacogenomic variants with large allele frequency differences between race/ethnicity groups in both cohorts. Frequency differences for toxicity-associated variants predict hundreds of adverse drug reactions per 1000 treated participants for minority groups in All of Us. Our results indicate that race and ethnicity can be used to stratify pharmacogenomic risk in the US and UK populations and should not be discounted when making treatment decisions. We resolve the contradiction between the results reported here and the orthodoxy of race and ethnicity as non-genetic, social constructs by emphasizing the distinction between global and local patterns of human genetic diversity, and we stress the current and future limitations of race and ethnicity as proxies for pharmacogenomic variation.

Safety, Tolerability and Pharmacokinetics of Single and Multiple Doses of Mirogabalin in Healthy Chinese Participants: A Randomized, Double-Blind, Placebo-Controlled Study

INTRODUCTION

Mirogabalin is a treatment option for patients with neuropathic pain; however, safety, tolerability, and pharmacokinetics (PK) data specifically for Chinese individuals are limited to a single-dose study. We aimed to assess these for both single- and multiple-dose mirogabalin in healthy Chinese participants.

METHODS

In this randomized, double-blind, placebo-controlled, phase I study, 54 healthy Chinese men and women aged 18-45 years were randomly allocated to receive single- (5, 10, or 15 mg, daily) or multiple-dose (5 mg titrated to 15 mg, twice-daily, over 22 days) oral mirogabalin or placebo. In each of three single-dose groups, 10 participants received mirogabalin and 2 received placebo; in the multiple-dose group, 14 participants received mirogabalin and 4 received placebo. The primary endpoints were PK, safety, and tolerability variables, including treatment-emergent adverse events (TEAEs), laboratory tests, and vital signs. PK data were collected for both single- and multiple-dose cohorts and evaluated by non-compartmental analysis.

RESULTS

Single- and multiple-dose mirogabalin was generally well tolerated with no deaths, serious TEAEs, or TEAEs leading to treatment discontinuation. Frequently reported TEAEs included dizziness, nystagmus, increased blood triglycerides, headache, and increased blood uric acid and creatine phosphokinase. Single-dose mirogabalin was rapidly absorbed (median time to maximum plasma concentration, 1.00 h) and eliminated (mean terminal elimination half-life, 2.57-3.08 h). The exposure was approximately dose-proportional. In the multiple-dose cohort, the trough plasma concentration increased dose-proportionally, and exposure and clearance were comparable to that following a single 15-mg dose. The mean cumulative amount excreted into urine up to 48 h post-dose increased in a dose-proportional manner, the mean cumulative percentage excreted into urine was 61.9%-74.3%, and renal clearance remained relatively constant.

CONCLUSION

Consistent with previous phase I studies in other populations, mirogabalin was safe and well tolerated in healthy Chinese participants at single and multiple doses of up to 15 mg twice-daily.

Therapeutic drug monitoring practices of anti-infectives: An Asia-wide cross-sectional survey

Objectives: The current practice of therapeutic drug monitoring (TDM) in Asia is poorly documented. Our aim was to capture and describe TDM services delivered in hospitals across Asia, including aspects such as assay availability, interpretation of results and clinical decision-making. Methods: An online survey about anti-infective TDM practices, available in English and involving 50 questions, was promoted to people involved in TDM in Asia. The survey was open for responses from September to November 2021. Results: Of 207 responses from participants working in 14 Asian countries, 150 responses from 10 countries could be included. TDM services are available for many anti-infectives, providing assays based on chromatographic assays (100.0%) or immunoassays (39.3%). Clinicians (82.6%) and pharmacists (86.8%) were responsible for ordering and interpreting TDM. Most services provided reference targets and dose recommendations. Interpretative support was available to a varying degree. Assay results were available and clinical decision-making could be completed within 24 h in most hospitals (87.9% and 88.9% respectively). As the turnaround time of assay results decreased, the proportion of clinical decision-making completed within 8 h increased. Barriers to implementation of TDM included lack of funding or equipment (71.1%), lack of clinician interest or cooperation (47.0%), and lack of expertise (42.3%). Lack of expertise was the primary barrier for using precision dosing software (50.5%). Conclusion: There are significant differences and challenges in the development and practice of anti-infective TDM in Asian countries.

Association between preoperative hypokalemia and postoperative complications in elderly patients: a retrospective study

Background

Hypokalemia is a common form of electrolyte disorder, which has a higher incidence in hospitalized patients and is closely related to perioperative complications and prognosis. Due to decreased skeletal muscle mass which causes total body potassium reduction, and increased comorbidities, the elderly are more susceptible to hypokalemia.

Objective

To investigate preoperative hypokalemia in elderly patients and its effect on postoperative complications.

Methods

Data were retrospectively collected from the elderly patients who underwent elective surgery from April 2018 to March 2019 and had preoperative blood gas data available. Patients, with age 60 to 100 years, were divided into hypokalemia group (potassium level < 3.5 mmol/L) and normokalemia group (potassium level between 3.5 and 5.5 mmol/L) according to preoperative blood gas analysis. Hypokalemia can be divided into mild (potassium level 3.0 to 3.5 mmol/L), moderate (potassium level 2.5 to 3.0 mmol/L) and severe (potassium level < 2.5 mmol/L), respectively. The risk factors of preoperative hypokalemia and its impact on postoperative complications and prognosis were primary outcomes. Secondary outcomes included postanesthesia care unit (PACU) stay time and hospital length of stay (LOS).

Results

Of 987 participants, 436 (44.17%) developed preoperative hypokalemia, among them 357 (81.88%) mild, 87 (16.74%) moderate and 6 (1.38%) severe. Multivariate logistic regression showed that female gender (OR, 1.851; 95% CI, 1.415–2.421), pre-existing hypokalemia at admission (OR, 4.498; 95% CI, 2.506–8.071), and oral laxative twice or more (OR, 1.823; 95% CI, 1.266–2.624) are risk factors of preoperative hypokalemia. Gynecological and biliopancreatic surgery were more common in hypokalemia group than normokalemia group (P <  0.001, P <  0.05). There was no significant difference in postoperative complications, PACU stay time, LOS, and 30-day mortality between the two groups (all P >  0.05).

Conclusions

Female gender, pre-existing hypokalemia at admission, and oral laxative twice or more are independent risk factors for preoperative hypokalemia in elderly patients. However, postoperative complications and 30-day mortality were not increased, which may be related to monitoring blood gas analysis and prompt correction of potassium levels during surgery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03445-1.

Pharmacokinetics and Safety of Erenumab after a Single Subcutaneous Injection Dose in Healthy Chinese Subjects

BACKGROUND AND OBJECTIVE

Erenumab is the first-in-class, selective, and competitive human monoclonal antibody antagonist of the calcitonin gene-related peptide (CGRP) receptor that has been shown to be effective and well-tolerated in the preventive therapy of episodic and chronic migraine. The pharmacokinetics of erenumab may be affected by differences in race and ethnicity, which can lead to suboptimal outcomes. The present study was conducted to assess the single-dose pharmacokinetics and safety of erenumab in healthy Chinese subjects.

METHODS

This was an open-label, randomized, parallel group, non-confirmatory, single-dose study in healthy Chinese subjects. A total of 24 healthy Chinese subjects of both sexes aged between 14 and 45 years were administered a single subcutaneous injection of erenumab 70 mg or 140 mg. The serum concentration of erenumab was quantified using a validated enzyme-linked immunosorbent assay method and pharmacokinetic parameters were determined using non-compartmental models. Safety was also assessed.

RESULTS

A total of 55 subjects were screened for eligibility and 25 subjects were randomized to receive study treatments (12 subjects to the 70-mg erenumab group and 13 subjects to the 140-mg erenumab group). Erenumab was absorbed slowly with maximum serum concentration (Cmax) occurring 3-11 days after administration. The mean Cmax and area under the serum concentration versus time curve from time 0 to infinity with extrapolation of the terminal phase (AUC0-∞) were 9.20 µg/mL and 296 day·µg/mL for the 70 mg dose group, and 15.6 µg/mL and 569 day·µg/mL for the 140 mg dose group, respectively. Serum concentrations of erenumab exhibited low to high variability, with variable coefficients ranging from 17.1 to 72.2% for the 70-mg dose and 32.5 to 88.5% for the 140-mg dose. All adverse events were mild or moderate in intensity, and all resolved without intervention.

CONCLUSIONS

Erenumab was safe and well tolerated after a single subcutaneous injection in healthy Chinese subjects. The systemic exposure in Chinese subjects in terms of AUC0-∞ was 70% higher than that in White subjects as previously reported.

CHINESE CLINICAL TRIAL REGISTRY NO

ChiCTR2000032435.

Ethnicity evaluation of ferric pyrophosphate citrate among Asian and Non-Asian populations: a population pharmacokinetics analysis

Purpose

To evaluate the potential ethnic differences of ferric pyrophosphate citrate (FPC, Triferic) in healthy subjects and patients with hemodialysis-dependent stage 5 chronic kidney disease (CKD-5HD) and identify covariates that may influence pharmacokinetics (PK) of FPC.

Methods

Data were collected from 2 Asian and 4 non-Asian clinical studies involving healthy subjects and CKD-5HD patients. Three population PK models were developed: M1 for intravenous (IV) administration of FPC in healthy subjects; M2 for dialysate administration of FPC in CKD-5HD patients; M3 for pre-dialyzer administration of FPC in CKD-5HD patients. All the models were fitted to concentration versus time data of FPC using the nonlinear mixed effect approach with the NONMEM^® program. All statistical analyses were performed using SAS version 9.4.

Results

In total, 26 Asians and 65 non-Asians were included in the final model analysis database. Forty healthy subjects were administered FPC via intravenous (IV) route and 51 patients with CKD-5HD via dialysate (N = 50) and pre-dialyzer blood circuit administration (N = 51). The PK parameters of FPC IV were similar. The population PK model showed good parameter precision and reliability as shown by model evaluation, and no relevant influence of ethnicity on PK parameters was observed. In healthy subjects, the maximum observed plasma concentration (C_max) and area under the plasma concentration–time curve (AUC) decreased with increase in lean body mass (LBM) and the average serum total iron at 6 h before the baseline period (Fe_av), whereas, in both patient populations, C_max and AUC decreased with increase in LBM and decrease in Fe_baseline. Other factors such as gender, age, Fe_av, and ethnicity had no influence on PK exposures in patients. The influence of LBM on PK exposures in patients was smaller than that in healthy subjects (ratio of AUC_0-24 for the 5th [68 kg] and 95th [45 kg] patient’s LBM was almost 1). The influence of Fe_av and LBM on PK exposures was < 50%.

Conclusion

The population pharmacokinetics model successfully described the PK parameters of FPC in healthy subjects and CKD-5HD patients and were comparable between Asian and non-Asian populations.

Supplementary information

The online version contains supplementary material available at 10.1007/s00228-022-03328-9.

A Phase I, Open-label, Single-Dose Study to Evaluate the Pharmacokinetics, Safety, and Tolerability of AMG 986 in Healthy Japanese Subjects

Background and Objective

AMG 986 is a first-in-class, novel apelin receptor small molecule agonist initially developed as a treatment for patients with heart failure (HF). Previously, a first-in-human study of AMG 986 was conducted in healthy and HF subjects; however, AMG 986 was not evaluated in Japanese subjects.

Methods

This was a phase I, open-label, single-dose, single-center study conducted to evaluate the safety and pharmacokinetics (PK) of AMG 986 200 mg and 400 mg in 12 healthy Japanese subjects. Six subjects received AMG 986 200 mg and six subjects received AMG 986 400 mg.

Results

Following oral administration, median time to maximum observed plasma concentration (t_max) was 1.0 h for both the AMG 986 200 mg and 400 mg groups, and mean terminal half-life (t_½) was 15.1 h and 17.6 h, respectively. When comparing the AMG 986 200 mg and 400 mg groups, 1.33-fold and 1.18-fold higher maximum observed plasma concentration (C_max) and AUC_∞, respectively, were observed for the 2-fold increase in dose. AMG 986 exhibited an acceptable safety and tolerability profile; all adverse events were mild in severity.

Conclusion

AMG 986 exposure increased with increasing dose, and the increase was less than dose proportional in healthy Japanese subjects. The results of this study could facilitate the subsequent clinical development of AMG 986 for the treatment of Japanese patients with HF.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40268-022-00386-3.

Long-term Safety and Efficacy of Esketamine Nasal Spray Plus an Oral Antidepressant in Patients with Treatment-resistant Depression- an Asian Sub-group Analysis from the SUSTAIN-2 Study

Objective

To evaluate the long-term safety and efficacy of intranasal esketamine in patients with treatment-resistant depression from the Asian subgroup of the SUSTAIN-2 study.

Methods

SUSTAIN-2 was a phase 3, open-label, single-arm, multicenter study comprising a 4-week screening, 4-week induction, 48-week optimization/maintenance, and 4-week follow-up (upon esketamine discontinuation) phase. Patients with treatment-resistant depression received esketamine plus an oral antidepressant during the treatment period.

Results

The incidence of ≥ 1 serious treatment-emergent adverse event (TEAE) among the 78 subjects from the Asian subgroup (Taiwan 33, Korea 26, Malaysia 19) was 11.5% (n = 9); with no fatal TEAE. 13 Asian patients (16.7%) discontinued esketamine due to TEAEs. The most common TEAEs were dizziness (37.2%), nausea (29.5%), dissociation (28.2%), and headache (21.8%). Most TEAEs were mild to moderate in severity, transient and resolved on the same day. Upon discontinuation of esketamine, no trend in withdrawal symptoms was observed to associate long-term use of esketamine with withdrawal syndrome. There were no reports of drug seeking, abuse, or overdose. Improvements in symptoms, functioning and quality of life, occurred during in the induction phase and were generally maintained through the optimization/maintenance phases of the study.

Conclusion

The safety and efficacy of esketamine in the Asian subgroup was generally consistent with the total SUSTAIN-2 population. There was no new safety signal and no indication of a high potential for abuse with the long-term (up to one year) use of esketamine in the Asian subgroup. Most of the benefits of esketamine occurred early during the induction phase.

Association of Drug-Metabolizing Enzyme and Transporter Gene Polymorphisms and Lipid-Lowering Response to Statins in Thai Patients with Dyslipidemia

Purpose

Statins are increasingly widely used in the primary and secondary prevention of cardiovascular disease. However, there is an inter-individual variation in statin response among patients. The study aims to determine the association between genetic variations in drug-metabolizing enzyme and transporter (DMET) genes and lipid-lowering response to a statin in Thai patients with hyperlipidemia.

Patients and Methods

Seventy-nine patients who received statin at steady-state concentrations were recruited. Serum lipid profile was measured at baseline and repeated after 4-month on a statin regimen. The genotype profile of 1936 DMET markers was obtained using Affymetrix DMET Plus genotyping microarrays.

Results

In this DMET microarray platform, five variants; SLCO1B3 (rs4149117, rs7311358, and rs2053098), QPRT (rs13331798), and SLC10A2 (rs188096) showed a suggestive association with LDL-cholesterol-lowering response. HDL-cholesterol-lowering responses were found to be related to CYP7A1 gene variant (rs12542233). Seven variants, SLCO1B3 (rs4149117, rs7311358, and rs2053098); SULT1E1 (rs3736599 and rs3822172); and ABCB11 (rs4148768 and rs3770603), were associated with the total cholesterol-lowering response. One variant of the ABCB4 gene (rs2109505) was significantly associated with triglyceride-lowering response.

Conclusion

This pharmacogenomic study identifies new genetic variants of DMET genes that are associated with the lipid-lowering response to statins. Genetic polymorphisms in DMET genes may impact the pharmacokinetics and lipid-lowering response to statin. The validation studies confirmations are needed in future pharmacogenomic studies.

Pharmacokinetics and Bioequivalence Studies of Roxatidine Acetate Hydrochloride Sustained-Release Capsule in Healthy Chinese Subjects

This study aimed to evaluate the bioequivalence between a generic roxatidine acetate hydrochloride (RAH) sustained-release capsule and brand-named formulation (ALTAT) under fasting and fed conditions. An open-label, single-center, randomized 2-period crossover study with a 5-day washout period was conducted. A single oral dose of 75-mg generic RAH sustained-release capsule (test drug) or a commercial capsule (reference drug) was given to healthy volunteers under fasting (n = 36) and fed conditions (n = 36). Blood samples were collected at baseline and during the 24 hours after dosing. The concentrations of roxatidine acetate (ROX) and bioactive metabolite roxatidine in plasma were detected using a validated high-performance liquid chromatography-tandem mass spectrometry method. Pharmacokinetic parameters were analyzed with noncompartmental methods. As prodrug, RAH was dehydrochloric acid to ROX in body and further rapidly converted to roxatidine. Such a rapid metabolism resulted in ROX that was hardly detected in plasma. Active metabolism roxatidine was therefore used to evaluate the pharmacokinetic process. The major pharmacokinetic parameters of roxatidine including peak plasma concentration, area under the plasma concentration-time curve from time 0 to time t, and area under the plasma concentration-time curve from time 0 to infinity were similar between the 2 preparations under fasting and fed conditions. The generic RAH sustained-release capsule is bioequivalent to the reference drug under fasting and fed conditions in healthy Chinese subjects.

Genetic Ancestry Inference for Pharmacogenomics

Genetic ancestry inference can be used to stratify patient cohorts and to model pharmacogenomic variation within and between populations. We provide a detailed guide to genetic ancestry inference using genome-wide genetic variant datasets, with an emphasis on two widely used techniques: principal components analysis (PCA) and ADMIXTURE analysis. PCA can be used for patient stratification and categorical ancestry inference, whereas ADMIXTURE is used to characterize genetic ancestry as a continuous variable. Visualization methods are critical for the interpretation of genetic ancestry inference methods, and we provide instructions for how the results of PCA and ADMIXTURE can be effectively visualized.

Pharmacokinetics of meropenem in critically ill patients in Saudi Arabia

Background

Meropenem is commonly used in the ICU to treat gram-negative infections. Due to various pathophysiological changes, critically ill patients are at higher risk of having subtherapeutic concentrations and hence have a higher risk of treatment failure—especially in regions where gram-negative drug resistance is increasing, such as Saudi Arabia. No studies have evaluated the pharmacokinetics of meropenem in critically ill patients in Saudi Arabia. Our primary objective is to assess the percentage of patients achieving the therapeutic target for meropenem.

Methods

This prospective observational study was conducted in the ICUs of King Khalid University Hospital. Patient were included if >18 years-of-age and received meropenem for a clinically suspected or proven bacterial infection. The primary outcome was to assess the percentage of patients who achieved the pharmacokinetic/pharmacodynamic (PKPD) therapeutic target of a free trough concentration four times the MIC. The secondary outcome was to estimate the pharmacokinetics of meropenem. Pharmacokinetic analysis was performed using Monolix Suite 2020R1 (Lixoft, France).

Results

Trough concentrations were highly variable and ranged from <0.5 µg/mL to 39 µg/mL, with a mean ± SD trough concentration of 8.5 ± 8 µg/mL. Only 46% of patients achieved the therapeutic target. The only significant predictor of failing to achieve the PKPD target was augmented renal clearance.

Conclusion

In conclusion, more than half of our patients did not achieve the PKPD target. Thus, there is a need for better dosing strategies of meropenem in critically ill patients in Saudi Arabia such as extended and continuous infusion.

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.

Representation of sex, race, and ethnicity in pivotal clinical trials for dermatological drugs

BACKGROUND

It is of paramount importance that clinical trials are designed with adequate health equity considerations to prevent disproportionate analyses of specific demographics.

OBJECTIVE

In this study, we investigated the representation of sex, race, and ethnicity in pivotal clinical trials for drugs with dermatological disease indications approved by the U.S. Food and Drug Administration between 1995 and 2019.

METHODS

Thirty-six novel drugs with indications to treat dermatological diseases, approved by the U.S. Food and Drug Administration between January 1995 and December 2019 were abstracted from Drugs@FDA. The drug approval label, statistical review, official record, and trial publication were reviewed for data on disease indication, approval year, pathway, number of participants, participant demographics (sex, race, and ethnicity), location, and sponsor type.

RESULTS

The overall female representation was 45.6% (n = 17,492 of 38,320). Adequate female representation was noted for five of six disease indications. Caucasians were predominantly overrepresented (80.4%; n = 28,065 of 34,890); Blacks (9.8%; n = 3242 of 33,240) and Asians (5.5%; n = 1535 of 27,696) were consistently underrepresented. Across sponsor types, there was a significant difference in the distribution of women (χ2 = 6.332; p = .042), as well as Caucasians (χ2 = 12.813; p = .002), Blacks (χ2 = 13.002; p = .002), and Hispanics/Latinos (χ2 = 7.747; p = .021).

CONCLUSION

Persistence of disparities disproportionately affect the quality of data behind therapies for certain demographics; as such, enrollment practices must continue to address the issue of underrepresentation. Efforts to facilitate demographic equity among clinical trial participants must be supported to ensure that safety and efficacy conclusions are drawn from representative population samples.

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

BACKGROUND AND OBJECTIVES

Omecamtiv mecarbil (OM) is a cardiac myosin activator under development for the treatment of heart failure. The pharmacokinetics of single and multiple doses of OM were investigated in healthy Japanese subjects in two clinical studies.

METHODS

Study 1 (n = 36) evaluated the bioavailability and pharmacokinetics after intravenous infusion (15 mg/h for 4 h) and an oral modified release (MR) tablet in healthy Japanese and Caucasian subjects using 25 mg single and multiple doses and 50 mg single dose. Study 2 (n = 50) evaluated the pharmacokinetics of OM with multiple oral doses of 25 mg MR tablets twice a day (BID) followed by up-titration to either 37.5 mg or 50 mg BID in healthy Japanese subjects.

RESULTS

In Study 1, the maximum observed plasma concentration (C_max) and area under the plasma concentration-time curve (AUC) from time 0 to infinity (AUC_inf) in Japanese subjects after a single oral dose of 50 mg were twice that at the 25 mg dose, consistent with that observed in Caucasian subjects. Following single oral doses of 25 mg and 50 mg, absolute bioavailability was 56.5% and 59.2% for Japanese subjects and 63.1 and 83.6% for Caucasian subjects, respectively. No ethnic differences were observed in the pharmacokinetics of OM and its metabolites following single and multiple doses of 25 mg and 50 mg. In Study 2, the mean accumulation ratios based on AUC from 0 to 12 h (AUC₁₂) were approximately four-fold from day 1 to day 8 and from day 20 to day 27 across ethnic groups. The mean ratios of C_max to predose concentrations (C_predose) ranged from 1.25 to 1.38 across subgroups.

CONCLUSIONS

OM showed consistent and predictable pharmacokinetics after multiple dosing in Japanese subjects.

Pharmacokinetics and tolerability of apremilast in healthy Korean adult men

We performed a two‐part study to evaluate the pharmacokinetics, safety, and tolerability of oral apremilast, a phosphodiesterase 4 inhibitor indicated for the treatment of psoriasis, in healthy Korean adult men. In part 1, there were 12 subjects who randomly received a single oral dose of apremilast at 20, 30, or 40 mg in each of 3 periods in a crossover fashion. In part 2, there were 16 subjects who randomly received 30 mg of apremilast or its matching placebo in a ratio of 3:1 twice daily for 14 days. Apremilast was rapidly absorbed (maximum concentration: ~2–3 h postdose), and eliminated according to a monoexponential pattern with a terminal‐phase elimination half‐life of 8–9 h. The exposure to apremilast increased in a dose‐proportional manner and accumulation was 1.6‐fold at steady‐state. Apremilast was well‐tolerated after a single oral administration and multiple oral administrations in Korean adult men; all of the treatment‐emergent adverse events were mild and recovered without sequelae. In conclusion, apremilast was safe and well‐tolerated in healthy Korean adult men when administered single oral doses of 20, 30, or 40 mg or when administered multiple oral doses of 30 mg b.i.d. for 14 days. Overall exposures increased in an approximate dose proportional manner in healthy Korean adult men.

Pharmacokinetics of Opicapone and Its Metabolites in Healthy White and Chinese Subjects

Opicapone (OPC) is a third-generation catechol-O-methyltransferase inhibitor developed to treat Parkinson disease and motor fluctuations. This open-label, single-center, phase 1 study aimed to evaluate the pharmacokinetics (PK) of OPC and its metabolites when administered as single and multiple doses in healthy White and Chinese subjects. The study enrolled a total of 30 White and Chinese healthy subjects, equally balanced among groups. The first dose of OPC was administered orally as a single dose of 50 mg on day 1, followed by a 10-day once-daily treatment from day 5 to day 14. Plasma concentrations of OPC and its metabolites were measured at 0 to 72 and 0 to 144 hours after dosing for single dose and multiple dose, respectively. Moreover, urine concentrations of OPC and its metabolite were measured 0 to 24 hours after dosing. PK parameters were derived from noncompartmental analysis. Geometric mean ratios and 90% confidence intervals for the main PK parameters were conducted to evaluate the ethnic difference between White and Chinese subjects. The plasma and urine exposure of OPC and its metabolites in Chinese subjects were similar to those in White subjects. These results indicated that ethnicity had no significant impact on PK of OPC between White and Chinese subjects.

Current challenges and future perspectives in oral absorption research: An opinion of the UNGAP network

Although oral drug delivery is the preferred administration route and has been used for centuries, modern drug discovery and development pipelines challenge conventional formulation approaches and highlight the insufficient mechanistic understanding of processes critical to oral drug absorption. This review presents the opinion of UNGAP scientists on four key themes across the oral absorption landscape: (1) specific patient populations, (2) regional differences in the gastrointestinal tract, (3) advanced formulations and (4) food-drug interactions. The differences of oral absorption in pediatric and geriatric populations, the specific issues in colonic absorption, the formulation approaches for poorly water-soluble (small molecules) and poorly permeable (peptides, RNA etc.) drugs, as well as the vast realm of food effects, are some of the topics discussed in detail. The identified controversies and gaps in the current understanding of gastrointestinal absorption-related processes are used to create a roadmap for the future of oral drug absorption research.

Population pharmacokinetic analysis of doripenem for Japanese patients in intensive care unit

We aimed to construct a novel population pharmacokinetics (PPK) model of doripenem (DRPM) for Japanese patients in intensive care unit, incorporating the clearance of DRPM by continuous renal replacement therapy (CRRT). Twenty-one patients treated with DRPM (0.25 or 0.5 g) by intravenous infusion over 1 h were included in the study. Nine of the 21 patients were receiving CRRT. Plasma samples were obtained before and 1, 2, 4, 6 and 8 h after the first DRPM administration. PPK analysis was conducted by nonlinear mixed effects modeling using a two-compartment model. Total clearance (CLtotal) in the model was divided into CRRT clearance (CLCRRT) and body clearance (CLbody). The final model was: CLtotal (L h-1) = CLbody(non-CRRT) = 3.65 × (Ccr/62.25)0.64 in the absence of CRRT, or = CLbody(CRRT) + CLCRRT = 2.49 × (Ccr/52.75)0.42 + CLCRRT in the presence of CRRT; CLCRRT = QE × 0.919 (0.919 represents non-protein binding rate of DRPM); V1 (L) = 10.04; V2 (L) = 8.13; and Q (L h-1) = 3.53. Using this model, CLtotal was lower and the distribution volumes (V1 and V2) tended to be higher compared to previous reports. Also, Ccr was selected as a significant covariate for CLbody. Furthermore, the contribution rate of CLCRRT to CLtotal was 30-40%, suggesting the importance of drug removal by CRRT. The population analysis model used in this study is a useful tool for planning DRPM regimen and administration. Our novel model may contribute greatly to proper use of DRPM in patients requiring intensive care.

Population structure and pharmacogenomic risk stratification in the United States

BACKGROUND

Pharmacogenomic (PGx) variants mediate how individuals respond to medication, and response differences among racial/ethnic groups have been attributed to patterns of PGx diversity. We hypothesized that genetic ancestry (GA) would provide higher resolution for stratifying PGx risk, since it serves as a more reliable surrogate for genetic diversity than self-identified race/ethnicity (SIRE), which includes a substantial social component. We analyzed a cohort of 8628 individuals from the United States (US), for whom we had both SIRE information and whole genome genotypes, with a focus on the three largest SIRE groups in the US: White, Black (African-American), and Hispanic (Latino). Our approach to the question of PGx risk stratification entailed the integration of two distinct methodologies: population genetics and evidence-based medicine. This integrated approach allowed us to consider the clinical implications for the observed patterns of PGx variation found within and between population groups.

RESULTS

Whole genome genotypes were used to characterize individuals' continental ancestry fractions-European, African, and Native American-and individuals were grouped according to their GA profiles. SIRE and GA groups were found to be highly concordant. Continental ancestry predicts individuals' SIRE with > 96% accuracy, and accordingly, GA provides only a marginal increase in resolution for PGx risk stratification. In light of the concordance between SIRE and GA, taken together with the fact that information on SIRE is readily available to clinicians, we evaluated PGx variation between SIRE groups to explore the potential clinical utility of race and ethnicity. PGx variants are highly diverged compared to the genomic background; 82 variants show significant frequency differences among SIRE groups, and genome-wide patterns of PGx variation are almost entirely concordant with SIRE. The vast majority of PGx variation is found within rather than between groups, a well-established fact for almost all genetic variants, which is often taken to argue against the clinical utility of population stratification. Nevertheless, analysis of highly differentiated PGx variants illustrates how SIRE partitions PGx variation based on groups' characteristic ancestry patterns. These cases underscore the extent to which SIRE carries clinically valuable information for stratifying PGx risk among populations, albeit with less utility for predicting individual-level PGx alleles (genotypes), supporting the concept of population pharmacogenomics.

CONCLUSIONS

Perhaps most interestingly, we show that individuals who identify as Black or Hispanic stand to gain far more from the consideration of race/ethnicity in treatment decisions than individuals from the majority White population.

Pharmacokinetics, Pharmacodynamics, and Safety of Peficitinib (ASP015K) in Healthy Male Caucasian and Japanese Subjects

BACKGROUND AND OBJECTIVE

Peficitinib pharmacokinetics and pharmacodynamics have been characterized mainly in Caucasian subjects. This study investigated the pharmacokinetics, pharmacodynamics, safety, and tolerability of peficitinib in healthy Japanese subjects compared with Caucasian subjects.

METHODS

In this single-center, randomized, double-blind, placebo-controlled study, a cohort of healthy Japanese (n = 24) and Caucasian (n = 24) men received a single oral dose of peficitinib (20, 60, or 200 mg) or placebo. Another cohort of Japanese men (n = 24) received peficitinib (10, 30, or 100 mg) or placebo twice daily for 7 days. Pharmacokinetic and pharmacodynamic parameters were assessed, and adverse events (AEs) monitored throughout.

RESULTS

Dose proportionality of maximum plasma drug concentration (C_max) and area under the plasma concentration-time curve extrapolated to infinity (AUC_inf) was demonstrated for both ethnicities. The geometric mean ratio for dose-normalized C_max was 45.7-98.8% higher and AUC_inf was 33.8-66.4% higher in Japanese versus Caucasian subjects. Mean peak inhibition of STAT5 phosphorylation was higher in Japanese than Caucasian subjects for a given peficitinib dose, but inhibition was comparable across ethnicities for a given plasma peficitinib concentration. In the multiple-dose study, plasma peficitinib concentrations were similar on day 1 and day 7. All AEs were mild, and none resulted in study discontinuation.

CONCLUSIONS

Peficitinib was well tolerated at doses up to 200 mg daily for 7 days in healthy Japanese subjects. Dose-proportional exposure was demonstrated across the single-dose range of 20-200 mg, with greater peficitinib exposure in Japanese compared with Caucasian subjects. The pharmacokinetic/pharmacodynamic relationships were considered comparable between these populations. CLINICALTRIALS.

GOV IDENTIFIER

NCT01225224.

Significant Unresolved Questions and Opportunities for Bioengineering in Understanding and Treating COVID-19 Disease Progression

COVID-19 is a disease that manifests itself in a multitude of ways across a wide range of tissues. Many factors are involved, and though impressive strides have been made in studying this novel disease in a very short time, there is still a great deal that is unknown about how the virus functions. Clinical data has been crucial for providing information on COVID-19 progression and determining risk factors. However, the mechanisms leading to the multi-tissue pathology are yet to be fully established. Although insights from SARS-CoV-1 and MERS-CoV have been valuable, it is clear that SARS-CoV-2 is different and merits its own extensive studies. In this review, we highlight unresolved questions surrounding this virus including the temporal immune dynamics, infection of non-pulmonary tissue, early life exposure, and the role of circadian rhythms. Risk factors such as sex and exposure to pollutants are also explored followed by a discussion of ways in which bioengineering approaches can be employed to help understand COVID-19. The use of sophisticated in vitro models can be employed to interrogate intercellular interactions and also to tease apart effects of the virus itself from the resulting immune response. Additionally, spatiotemporal information can be gleaned from these models to learn more about the dynamics of the virus and COVID-19 progression. Application of advanced tissue and organ system models into COVID-19 research can result in more nuanced insight into the mechanisms underlying this condition and elucidate strategies to combat its effects.

Clinical Experiences of Intravenous Hydralazine and Labetalol for Acute Treatment of Severe Hypertension in Pregnant Thai Women

Response to acute treatment of severe hypertension during pregnancy in Asian women was not known. Labor and delivery checklists of Thai women treated with intravenous hydralazine or labetalol for systolic blood pressure (SBP) ≥ 160 or diastolic blood pressure (DBP) ≥ 110 mm Hg from January 2011 to December 2013 were reviewed as parts of an audit. Primary outcome was prompt achievement of SBP 140-150 and DBP 90-100 mm Hg after the first bolus. Secondary outcomes were medication-related undesired effects. The mean ± standard deviation age and prevalence of chronic hypertension in hydralazine (n = 62) versus labetalol (n = 64) groups were 32.5 ± 6 versus 29.9 ± 6.8 years and 50% versus 21.9%, respectively (P < .05). Magnesium sulfate was promptly administered on admission to every woman to prevent seizure. Targeted blood pressure was timely achieved in 41.9% and 67.2% of the hydralazine and labetalol groups, respectively (P < .05). Nonreassuring fetal heart rate occurred in 51.6% and 32.8% of the hydralazine and labetalol groups, respectively (P = .05). The prevalence of cesarean section and Apgar score < 7 were not significantly different (P > .05). Real-life clinical experiences suggested significant advantages of intravenous labetalol over hydralazine in pregnant women with severe hypertension.

Oral Ciprofloxacin Pharmacokinetics in Healthy Mexican Volunteers and Other Populations: Is There Interethnic Variability?

BACKGROUND

There is evidence that the pharmacokinetics of certain drugs in Mexicans may differ with respect to other ethnic groups. On the other hand, there is controversy about the existence of interethnic variability in the pharmacokinetics of ciprofloxacin.

AIM OF THE STUDY

To study oral ciprofloxacin pharmacokinetics in Mexicans at various dose levels and make comparisons with other populations in order to gain insight on interethnic variability.

METHODS

Healthy Mexican volunteers received oral ciprofloxacin as 250 mg and 500 mg immediate-release tablets or a 1,000 mg extended-release formulation. Plasma concentration against time curves were constructed, and pharmacokinetic parameters were compared with those reported for other populations.

RESULTS

Ciprofloxacin pharmacokinetics in Mexicans was linear and no significant differences between males and females were detected. When several populations were compared, it appeared that bioavailability in Mexicans was similar to that of Caucasians, being lower than that of Asians. These variations were attenuated when data were normalized by body weight.

CONCLUSIONS

Ciprofloxacin pharmacokinetics exhibit interethnic variability, Asians exhibiting an increased bioavailability with regard to Mexicans and Caucasians. Data suggest that these differences are due to body weight.

Safety and effectiveness of lurasidone for the treatment of schizophrenia in Asian patients: Results of a 26-week open-label extension study

INTRODUCTION

This study was designed to evaluate the long-term safety and effectiveness of lurasidone in the treatment of schizophrenia among Asian patients.

METHODS

Patients (N = 281) with schizophrenia who had completed a randomized, double-blind (DB), 6-week comparison of lurasidone (40 and 80 mg/day) and placebo were enrolled in a 26-week extension study in which all patients received open-label (OL), flexible doses of lurasidone (40 or 80 mg/day). Effectiveness was measured using the Positive and Negative Syndrome Scale (PANSS) scale.

RESULTS

Fifty-seven percent of patients completed the OL extension study; 16.7% discontinued early due to lack of effectiveness; and 10.3% due to adverse events. The most common adverse events were insomnia (11.3%), akathisia (11.0%), and nasopharyngitis (10.6%). Adverse events related to weight gain, metabolic parameters, prolactin, and ECG measures were uncommon. Mean change in the PANSS total score from the DB baseline to OL endpoint was -28.4, with mean improvement of -7.5 observed from baseline to OL endpoint, and with a PANSS responder rate of 73.7%.

DISCUSSION

The results of the current 26-week extension study found lurasidone to be a generally safe, well-tolerated, and effective long-term treatment for schizophrenia in Asian patients.

Hormonal status affects plasma exposure of tamoxifen and its main metabolites in tamoxifen-treated breast cancer patients

Background

Tamoxifen is considered a prodrug of its active metabolite endoxifen, which is dependent on the CYP2D6 and CYP3A enzymes. Tamoxifen pharmacokinetic variability influences endoxifen exposure and, consequently, its clinical outcome. This study investigated the impact of hormonal status on the pharmacokinetics of tamoxifen and its metabolites in TAM-treated breast cancer patients.

Methods

TAM-treated breast cancer patients (n = 40) previously believed to have CYP3A activity within the normal range based on oral midazolam and phenotyped as CYP2D6 normal metabolizers using oral metoprolol were divided into two groups according to premenopausal (n = 20; aged 35–50 years) or postmenopausal (n = 20; aged 60–79 years) status. All patients were treated with 20 mg/day tamoxifen for at least three months. Serial plasma samples were collected within the 24 h dose interval for analysis of unchanged tamoxifen, endoxifen, 4-hydroxytamoxifen and N-desmethyltamoxifen quantified by LC-MS/MS. CYP activities were assessed using midazolam apparent clearance (CYP3A) and the metoprolol/alfa-hydroxymetoprolol plasma metabolic ratio (CYP2D6). CYP3A4, CYP3A5 and CYP2D6 SNPs and copy number variation were investigated using TaqMan assays.

Results

Postmenopausal status increased steady-state plasma concentrations (Css) of tamoxifen (116.95 vs 201.23 ng/mL), endoxifen (8.01 vs 18.87 ng/mL), N-desmethyltamoxifen (485.16 vs 843.88 ng/mL) and 4-hydroxytamoxifen (2.67 vs 4.11 ng/mL). The final regression models included hormonal status as the only predictor for Css of tamoxifen [β-coef ± SE, p-value (75.03 ± 17.71, p = 0.0001)] and 4-hydroxytamoxifen (1.7822 ± 0.4385, p = 0.0002), while endoxifen Css included hormonal status (8.578 ± 3.402, p = 0.02) and race (11.945 ± 2.836, p = 0.007). For N-desmethyltamoxifen Css, the final model was correlated with hormonal status (286.259 ± 76.766, p = 0.0007) and weight (− 8.585 ± 3.060, p = 0.008).

Conclusion

The premenopausal status was associated with decreased endoxifen plasma concentrations by 135% compared to postmenopausal status. Thus, the endoxifen plasma concentrations should be monitored mainly in the premenopausal period to maintain plasma levels above the efficacy threshold value.

Trial registration

RBR-7tqc7k.

Are we all the same? The critical role of translational brain, behavior, and immunity research in East Asia

Traditional Chinese medicine (TCM) is founded on the idea that the "Mind and Body" are all interconnected. When you have a difficult time or disturbing lifestyle and experience a series of somatic and psychological symptoms mimicking inflammation-induced sickness behaviors, the TCM practitioners would be very likely to give you a diagnosis of "On Fire" and prescribe specific food intervention and herbal medicine, which might be considered anti-inflammatory to "cool you down." Psychoneuroimmunology has been long stemmed in ancient medicine.

Influence of Calcineurin Inhibitor and Sex on Mycophenolic Acid Pharmacokinetics and Adverse Effects Post-Renal Transplant

Tacrolimus or cyclosporine is prescribed with mycophenolic acid posttransplant and contributes to interpatient variability in mycophenolic acid pharmacokinetics and response. Cyclosporine inhibits enterohepatic circulation of the metabolite mycophenolic acid glucuronide, which is not described with tacrolimus. This study investigated mycophenolic acid pharmacokinetics and adverse effects in stable renal transplant recipients and the association with calcineurin inhibitors, sex, and race. Mycophenolic acid and mycophenolic acid glucuronide area under the concentration-time curve from 0 to 12 hours (AUC0-12h ) and apparent clearance were determined at steady state in 80 patients receiving cyclosporine with mycophenolate mofetil and 67 patients receiving tacrolimus with mycophenolate sodium. Gastrointestinal adverse effects and hematologic parameters were evaluated. Statistical models evaluated mycophenolic acid pharmacokinetics and adverse effects. Mycophenolic acid AUC0-12h was 1.70-fold greater with tacrolimus (68.9 ± 30.9 mg·h/L) relative to cyclosporine (40.8 ± 17.6 mg·h/L); P < .001. Target mycophenolic acid AUC0-12h of 30-60 mg·h/L was achieved in 56.3% on cyclosporine compared with 34.3% receiving tacrolimus (P < .001). Mycophenolic acid clearance was 48% slower with tacrolimus (10.6 ± 4.7 L/h) relative to cyclosporine (20.5 ± 10.0 L/h); P < .001. Enterohepatic circulation occurred less frequently with cyclosporine (45%) compared with tacrolimus (78%); P < 0.001; with a 2.9-fold greater mycophenolic acid glucuronide AUC0-12h to mycophenolic acid AUC0-12h ratio (P < .001). Race did not affect mycophenolic acid pharmacokinetics. Gastrointestinal adverse effect scores were 2.2-fold higher with tacrolimus (P < .001) and more prominent in women (P = .017). Lymphopenia was more prevalent with tacrolimus (52.2%) than cyclosporine (22.5%); P < 0.001. Calcineurin inhibitors and sex contributed to interpatient variability in mycophenolic acid pharmacokinetics and adverse effects post-renal transplant, which could be attributed to differences in enterohepatic circulation.

Essential(ist) medicine: promoting social explanations for racial variation in biomedical research

Biomedical research has a long and complicated history as a tool of oppression, exemplary of the racial science used to legitimise and maintain racial hierarchies in the USA and abroad. While the explicit racism and racial inferiority supported by this research has dissipated and modern methods of inquiry have increased in sophistication and rigor, contemporary biomedical research continues to essentialise race by distilling racial differences and disparities in health to an underlying, biogenetic source. Focusing on the persistence of essentialism in an era of genomic medicine, this paper examines the deep social origins and social implications of the essentialist viewpoint in biomedicine and how it relates to the broader construction of social and scientific knowledge. Invoking Hacking's 'looping effects' as a useful conceptual tool, I then demonstrate how sociohistorical forces influence scientific and medical research in producing evidence that favours and legitimises a biological construction of race. I extend the looping framework to consider a parallel 'louping' process whereby applying a socially rooted meaning to race in biomedical research results becomes magnified to influence social norms and ideas about race. As many biomedical researchers are motivated by a desire to eliminate racial disparities in outcomes, I argue that greater social acuity allows scientists to avoid individualising and racialising health, challenge preconceived assumptions about the meaning of racial variation in health and medicine and thus promote and strengthen a socioenvironmental focus on how to best improve individuals' and population health. Concluding with a call for structural competency in biomedical research, I suggest that empowering scientists to more freely discuss sociostructural factors in their work allows for the continued use of race in biological and medical research, while social scientists and medical humanities scholars stand to benefit from seeing their work imbued with the cultural authority currently granted to biomedicine.

Science-based Ethnic Bridging in Drug Development; Review of Recent Precedence and Suggested Steps Forward

BACKGROUND

Exposure, safety and/or efficacy of drugs are subject to potential differences between human races or ethnicities, as acknowledged by regulatory guidance and by label texts of various, but not all approved drugs.

OBJECTIVE

The objective of the present review was to assess recent regulatory precedence on drug use and race or ethnicity, with the goal of identifying opportunities for increasing the informative value of clinical ethnic or racial bridging in drug development.

METHODS

Recently, (January 2014-July 2018) FDA approved drug product label texts and approval packages were reviewed for claims, comments and underlying data on use of the product in specific ethnic or racial groups.

RESULTS

Among the 266 FDA-approved products, no product with unambiguous race- or ethnicity specific dosing instructions was retrieved. A small majority (55%) was approved with a claim or comment on race or ethnicity, and of these, a large majority (87%) was based on population pharmacokinetic data analysis. Statements were often related to incidence of a genotype for drug metabolizing enzyme or for other risk factors, or were related to body weight. Absence of clinically relevant exposure differences were often justified in terms of exposure ratios that notably exceeded the typical 0.80-1.25 no-effect boundary.

CONCLUSIONS

Recent precedence reflected a pragmatic, descriptive approach of racial or ethnic bridging, apparently meeting current regulatory expectations, whilst not resulting in strict guidance to prescribers. We recommend further work on defining the objectives of bridging studies, as well as criteria for their design and data analysis. Regarding the latter, we recommend investigating the value of prospectively defined tests for similarity with appropriate follow-up analysis in the case where the test has failed.

Ataluren Pharmacokinetics in Healthy Japanese and Caucasian Subjects

To evaluate the potential for ethnicity-related differences in ataluren pharmacokinetics (PK) and safety, a phase 1 single-dose study was conducted in 48 healthy (24 Japanese and 24 Caucasian subjects), nonsmoking male volunteers who were equally divided into 3 cohorts of oral doses at 5, 10, and 20 mg/kg. Blood samples were collected until 48 hours postdose. PK results demonstrated rapid absorption of ataluren, with peak plasma levels (C_max ) being attained between 0.875 and 2.5 hours after dosing. The mean C_max and area under the concentration-time curve (AUC_(0-last) ) increased with each increasing dose level in both Japanese and Caucasian subjects. Although the C_max was similar across all subjects at each dose regardless of ethnicity, Japanese subjects had a mean AUC_(0-last) approximately 14% to 34% lower than that of Caucasian subjects across the 3 dose levels. This difference was likely due to the higher variability of AUC values in Caucasian subjects and the relatively small study population. In conclusion, similar ataluren PK profiles were observed in healthy Japanese and Caucasian subjects following single oral administration of ataluren at all dose levels.

Pharmacokinetics, Tolerability, and Bioequivalence of Two Formulations of Rotigotine in Healthy Chinese Subjects

PURPOSE

The pharmacokinetic (PK) profile of the rotigotine transdermal patch is well characterized in Caucasian patients with Parkinson's disease (PD) but not in Chinese subjects. This article reports the PK variables, safety, and tolerability of the rotigotine transdermal patch (2 mg/24 hours and 4 mg/24 hours cold-chain PR2.1.1 formulation) in healthy Chinese subjects (SP0913; NCT01675024). A second study (PD0011; NCT02070796) evaluated the relative bioavailability of cold-chain (PR2.1.1) and room temperature-stable (PR2.2.1) formulations of rotigotine in healthy Chinese men.

METHODS

In treatment period 1 of SP0913, subjects received a single application of rotigotine 2 mg/24 hours on day 1 followed by a washout period (days 2-6); treatment period 2 (days 6-14) involved multiple doses of rotigotine 2 mg/24 hours (days 7-9) followed by multiple doses of rotigotine 4 mg/24 hours (days 10-12), with patches applied for 24 hours each. In PD0011, subjects received a single dose (2 mg/24 hours) of each rotigotine formulation (PR2.2.1 and PR2.1.1) for 24 hours each in a crossover design. Blood samples were collected at scheduled time points to determine rotigotine plasma concentrations. Safety and tolerability were evaluated by adverse events monitoring.

RESULTS

Twenty-four healthy Chinese subjects (12 males, 12 females) were enrolled and completed SP0913. Geometric mean plasma concentrations of unconjugated and total rotigotine increased to a plateau beginning at ∼8 hours (multiple dose) to 16 hours (single dose) postdose; no characteristic T_max was observed for unconjugated and total rotigotine. The respective geometric mean C_max, C_max,ss, AUC from zero up to the last analytically quantifiable concentration, and AUC_0-24,ss values for unconjugated and total rotigotine were similar when rotigotine 2 mg/24 hours was applied as a single dose or multiple-dose regimen. During the multiple-dose period, geometric mean C_max,ss and AUC_0-24,ss of both unconjugated and total rotigotine were ∼2-fold higher for rotigotine 4 mg/24 hours than for rotigotine 2 mg/24 hours. Forty-seven of 50 male Chinese subjects completed PD0011. Primary PK parameters for the room temperature-stable formulation of rotigotine were highly comparable to the cold-chain formulation. Common adverse events included application site pruritus, nausea, dizziness, and constipation (SP0913 only), with no clinically significant changes in other safety measures.

IMPLICATIONS

PK profiles and derived PK parameters of unconjugated and total rotigotine in healthy Chinese subjects were consistent with findings from other ethnic groups receiving single and multiple doses of the rotigotine transdermal patch. Single and repeated daily doses of the rotigotine transdermal patch were well tolerated. Room temperature-stable and cold-chain formulations were bioequivalent. ClinicalTrials.gov identifiers: NCT01675024 and NCT02070796.

Population Pharmacokinetic Analysis of Meropenem After Intravenous Infusion in Korean Patients With Acute Infections

PURPOSE

The aim of this study was to investigate the population pharmacokinetic (PK) profile of meropenem in Korean patients with acute infections.

METHODS

The study included 37 patients with a creatinine clearance ≤50 or >50 mL/min who received a 500- or 1000-mg dose of meropenem, respectively, infused intravenously over 1 hour every 8 hours. Blood samples were collected before and at 1, 1.5, and 5 hours after the start of the fourth infusion. The population PK analysis was conducted by using nonlinear mixed effect modeling software (NONMEM). Monte-Carlo simulations were performed to identify optimal dosing regimens.

FINDINGS

Thirty-seven subjects completed the study. Meropenem PK variables were well described by using a one-compartment model. The typical values (relative SE) for weight-normalized clearance (CL) and V_d were 0.266 L/h/kg (12.29%) and 0.489 L/kg (11.01%), respectively. Meropenem CL was significantly influenced by the serum creatinine level, which explained 11% of the interindividual CK variability. The proposed equation to estimate meropenem CL in Korean patients was as follows: CL (L/h) = 0.266 × weight × [serum creatinine/0.74]^-1.017_. The simulation results indicate that the current meropenem dosing regimen may be suboptimal in patients infected with normal or augmented renal function.

IMPLICATIONS

Prolonged infusions of meropenem over at least 2 hours should be considered, especially in patients with augmented renal function and those infected with pathogens for which the minimum inhibitory meropenem concentration is >1 μg/mL. Our results suggest an individualized meropenem dosing regimen for patients with abnormal renal function and those infected with pathogens with decreased in vitro susceptibility.

Using a Model to Design Activity-Based Educational Experiences to Improve Cultural Competency among Graduate Students

To improve the cultural competency of 34 students participating in graduate nutrition counseling classes, the Campinha-Bacote Model of Cultural Competence in the Delivery of Health Care Services was used to design, implement, and evaluate counseling classes. Each assignment and activity addressed one or more of the five constructs of the model, i.e., knowledge, skill, desire, encounters, and awareness. A repeated measure ANOVA evaluated pre- and post-test cultural competence scores (Inventory for Assessing the Process of Cultural Competence among Healthcare Professionals). The overall cultural competence score significantly improved (p < 0.001) from "culturally aware" (68.7 at pre-test) to "culturally competent" (78.7 at post-test). Students significantly improved (p < 0.001) in four constructs of the model including awareness, knowledge, skill, and encounter. Factor analysis indicated that course activities accounted for 83.2% and course assignments accounted for 74.6% of the total variance of cultural competence. An activity-based counseling course encouraging self-evaluation and reflection and addressing Model constructs significantly improved the cultural competence of students. As class activities and assignments aligned well with the Campinha-Bacote Model constructs, the findings of this study can help guide health educators to design effective cultural competence training and education programs.

A Review of Insulin Degludec/Insulin Aspart: Pharmacokinetic and Pharmacodynamic Properties and Their Implications in Clinical Use

Insulin degludec/insulin aspart (IDegAsp; 70 % IDeg and 30 % IAsp) is a soluble combination of two individual insulin analogues in one product, designed to provide mealtime glycaemic control due to the IAsp component and basal glucose-lowering effect from the IDeg component. The pharmacokinetic and pharmacodynamic characteristics of IDegAsp have been investigated in a series of clinical pharmacology studies with generally comparable designs, methodologies and patient inclusion/exclusion criteria. The glucose-lowering effect profile of IDegAsp during once-daily dosing at steady state shows distinct and clearly separated action from the prandial and basal components of IDegAsp. The IAsp component provides rapid onset and peak glucose-lowering effect followed by a flat glucose-lowering effect lasting beyond 30 h due to IDeg. During twice-daily dosing, the distinct peak effect and the flat basal effect are retained following each dose. The pharmacological properties of IDegAsp are maintained in the elderly, children, adolescents, Japanese patients and those with hepatic or renal impairment. The potential clinical benefits associated with the pharmacological properties of IDegAsp have been verified in phase III clinical trials comparing IDegAsp with three other currently available treatment options: premixed insulin, basal-bolus regimens and basal-only therapy. IDegAsp shows favourable clinical benefits compared with biphasic insulin aspart 30 and is a viable alternative to basal-bolus and basal-only therapy. This review presents the results from clinical pharmacology studies conducted with IDegAsp to date, and extrapolates these results to clinical use of IDegAsp in the context of findings from the IDegAsp clinical therapeutic studies.

Pharmacokinetic considerations for use of artemisinin-based combination therapies against falciparum malaria in different ethnic populations

INTRODUCTION

Artemisinin-based combination therapy (ACT) is used extensively as first-line treatment for uncomplicated falciparum malaria. There has been no rigorous assessment of the potential for racial/ethnic differences in the pharmacokinetic properties of ACTs that might influence their efficacy. Areas covered: A comprehensive literature search was performed that identified 72 publications in which the geographical origin of the patients could be ascertained and the key pharmacokinetic parameters maximum drug concentration (C_max), area under the plasma concentration-time curve (AUC) and elimination half-life (t_½β) were available for one or more of the five WHO-recommended ACTs (artemether-lumefantrine, artesunate-amodiaquine, artesunate-mefloquine, dihydroartemisinin-piperaquine and artesunate-sulfadoxine-pyrimethamine). Comparisons of each of the three pharmacokinetic parameters of interest were made by drug (artemisinin derivative and long half-life partner), race/ethnicity (African, Asian, Caucasian, Melanesian, South American) and patient categories based on age and pregnancy status. Expert opinion: The review identified no evidence of a clinically significant influence of race/ethnicity on the pharmacokinetic properties of the nine component drugs in the five ACTs currently recommended by WHO for first-line treatment of uncomplicated falciparum malaria. This provides reassurance for health workers in malaria-endemic regions that ACTs can be given in recommended doses with the expectation of adequate blood concentrations regardless of race/ethnicity.

Population Pharmacokinetic Analysis of Doripenem after Intravenous Infusion in Korean Patients with Acute Infections

We investigated the population pharmacokinetics (PK) of doripenem in Korean patients with acute infections and determined an appropriate dosing regimen using a Monte Carlo simulation for predicting pharmacodynamics (PD). Patients (n = 37) with a creatinine clearance (CL_CR) of 20 to 50 ml/min or >50 ml/min who received a 250-mg or 500-mg dose of doripenem over the course of 1 h every 8 h, respectively, were included in this study. Blood samples were taken predosing and 0 h, 0.5 h, and 4 to 6 h after the fourth infusion. A nonlinear mixed-effect modeling tool was used for the PK analysis and pharmacodynamic simulation; doripenem PK were well described by a one-compartment model. The population mean values of the body weight (WT)-normalized clearance (CL/WT) and the body weight-normalized volume of distribution (V/WT) were 0.109 liter/h/kg of body weight (relative standard error, 9.197%) and 0.280 liter/kg (relative standard error, 9.56%), respectively. Doripenem CL was significantly influenced by CL_CR The proposed equation to estimate doripenem CL in Korean patients was CL/WT = 0.109 × WT × (CL_CR/57)^0.688, where CL/WT is in liters per hour per kilogram. CL in Korean patients was expected to be lower than that in Caucasian patients, regardless of renal function. The Monte Carlo simulation showed that 90% attainment of target PK/PD magnitudes could be achieved with the usual dosing regimens when the MIC was ≤1 mg/liter. However, prolonged infusions (4 h) should be considered, especially when patients have augmented renal function and for patients infected with pathogens with a high MIC. Our results provide an individualized doripenem dosing regimen for patients with various renal functions and for patients infected with bacteria with decreased susceptibility.

Research Professionals' Perspectives, Barriers, and Recommendations Regarding Minority Participation in Clinical Trials

OBJECTIVE

This study aims to investigate research professionals' perspectives regarding minority participation in clinical trials.

METHODS

A web-based survey of research professionals at US institutions receiving NIH and/or AHRQ funding to conduct clinical research in 2013. Descriptive statistics, mean, standard deviation (SD), and the Wilcoxon rank-sum test were utilized for analysis.

RESULTS

Distributed were 13,041 surveys with 967 (7.4%) responses. Overall and race-stratified analyses included 633 and 521 surveys, respectively. A majority agreed that patients' race (mean, 3.4; SD = 1.0) and primary language (mean, 4.0; SD = 0.9) have an effect on enrollment. They had more success in enrolling those whose primary language was the same as their own (mean, 3.8; SD = 1.0), and that a language barrier and time spent arranging for interpreters had prevented them from offering a study to potential candidates (mean, 3.2; SD = 1.2). Non-Caucasian respondents were more likely to agree that "fear of unknown side effects" was a deterrent for minorities (p < 0.01), "minorities are more likely to be unavailable for follow-up phone calls" (p = 0.07), and "the unavailability of translated material discourages non-English speakers from participation" (p = 0.08). They also were more likely to be neutral or agree with being discouraged from enrolling minorities because of the possibility of their withdrawal or being less likely to be available for phone follow-ups and follow-up visits (all p < 0.01).

CONCLUSION

Despite a few subtle racial differences in research professionals' perspectives, a majority expressed no hesitation in enrolling minorities. Patients' race and primary language appeared to influence enrollment. A language barrier appeared to be the strongest barrier for research professionals.

Inter-rater variability of visual interpretation and comparison with quantitative evaluation of 11C-PiB PET amyloid images of the Japanese Alzheimer's Disease Neuroimaging Initiative (J-ADNI) multicenter study

PURPOSE

The aim of this study was to assess the inter-rater variability of the visual interpretation of ¹¹C-PiB PET images regarding the positivity/negativity of amyloid deposition that were obtained in a multicenter clinical research project, Japanese Alzheimer's Disease Neuroimaging Initiative (J-ADNI). The results of visual interpretation were also compared with a semi-automatic quantitative analysis using mean cortical standardized uptake value ratio to the cerebellar cortex (mcSUVR).

METHODS

A total of 162 ¹¹C-PiB PET scans, including 45 mild Alzheimer's disease, 60 mild cognitive impairment, and 57 normal cognitive control cases that had been acquired as J-ADNI baseline scans were analyzed. Based on visual interpretation by three independent raters followed by consensus read, each case was classified into positive, equivocal, and negative deposition (ternary criteria) and further dichotomized by merging the former two (binary criteria).

RESULTS

Complete agreement of visual interpretation by the three raters was observed for 91.3% of the cases (Cohen κ = 0.88 on average) in ternary criteria and for 92.3% (κ = 0.89) in binary criteria. Cases that were interpreted as visually positive in the consensus read showed significantly higher mcSUVR than those visually negative (2.21 ± 0.37 vs. 1.27 ± 0.09, p < 0.001), and positive or negative decision by visual interpretation was dichotomized by a cut-off value of mcSUVR = 1.5. Significant positive/negative associations were observed between mcSUVR and the number of raters who evaluated as positive (ρ = 0.87, p < 0.0001) and negative (ρ = -0.85, p < 0.0001) interpretation. Cases of disagreement among raters showed generally low mcSUVR.

CONCLUSIONS

Inter-rater agreement was almost perfect in ¹¹C-PiB PET scans. Positive or negative decision by visual interpretation was dichotomized by a cut-off value of mcSUVR = 1.5. As some cases of disagreement among raters tended to show low mcSUVR, referring to quantitative method may facilitate correct diagnosis when evaluating images of low amyloid deposition.

Population Pharmacokinetic Analysis of Piperacillin/Tazobactam in Korean Patients with Acute Infections

Background

For more effective and safer usage of antibiotics, the dosing strategy should be individualized based on the patients’ characteristics, including race. The aim of this study was to investigate the population pharmacokinetic (PK) profiles of piperacillin and tazobactam in Korean patients with acute infections.

Materials and Methods

At least four consecutive 2/0.25 g or 4/0.5 g doses of piperacillin/tazobactam (TZP) were intravenously infused over 1 h every 8 h for patients with creatinine clearance (CL_cr) ≤50 ml/min or CL_cr >50 mL/min, respectively. Blood samples from 33 patients at a steady-state were taken pre-dose and at 0 min, 30 min, and 4-6 h after the fourth infusion. The population PK analysis was conducted using a non-linear mixed-effects method. A likelihood ratio test was used to select significant covariates, with significance levels of P <0.05 for selection and P <0.01 for elimination.

Results

Both piperacillin PK and tazobactam PK were well described by a two-compartment model with first-order elimination. Creatinine clearance and body weight, as covariates on clearance (CL) and volume of central compartment (V1), were selected among the covariates possibly affecting PK parameters of both drugs. CL was defined as CL = 2.9 + 4.03 × CL_cr /47 for piperacillin and CL = 1.76 + 4.81 × CL_cr /47 for tazobactam. V1 was defined as V1 = 19.5 × weight/60 for piperacillin and V1 = 22.6 × weight/60 for tazobactam.

Conclusion

The PK profiles of TZP at a steady-state in Korean patients with acute infections were well described by a two-compartment model with first-order elimination. Both piperacillin and tazobactam clearances were significantly influenced by creatinine clearance.

Insulin degludec/insulin aspart in Japanese patients with type 1 diabetes mellitus: Distinct prandial and basal glucose-lowering effects

AIMS/INTRODUCTION

Insulin degludec/insulin aspart (IDegAsp) is a soluble co-formulation of long-acting insulin degludec (IDeg) and rapid-acting insulin aspart (IAsp). The present study investigated the pharmacodynamic properties of IDegAsp in Japanese patients with type 1 diabetes mellitus.

MATERIALS AND METHODS

In this randomized, double-blind, two-period, cross-over trial, 21 Japanese patients with type 1 diabetes mellitus received single doses of 0.5 U/kg IDegAsp and biphasic insulin aspart 30 in a randomized sequence (13-21 days washout between treatments). The pharmacodynamic response was evaluated in a 26-h euglycemic glucose clamp (target 5.5 mmol/L). Single-dose IDegAsp glucose infusion rate (GIR) profiles were extrapolated to steady state using modeling.

RESULTS

The IDegAsp single-dose GIR profile showed a clear distinction between the effects of the bolus (IAsp) and basal (IDeg) components in IDegAsp. When simulated to steady state, the GIR profile of IDegAsp was shifted upwards compared with the single-dose profile, and showed a rapid onset of action and a distinct peak from the IAsp component followed by a separate and sustained basal action from the long-acting IDeg component. For biphasic insulin aspart 30, the initial shape of the GIR profile was similar to IDegAsp, but GIR continuously decreased from maximum and reached zero 18-20 h post-dosing. The characteristics of the GIR profile for IDegAsp were retained when simulated to steady state in a twice-daily dosing regimen.

DISCUSSION

In Japanese patients with type 1 diabetes mellitus, the pharmacodynamic profile of IDegAsp is characterized by distinct prandial and basal effects from the IAsp and IDeg components, consistent with what has been reported previously in Caucasian patients with type 1 diabetes mellitus.