A novel system to determine activity of individual uridine 5'-diphospho-glucuronosyltransferase (UGT) isoforms: Recombinant UGT-beads.

Previous work demonstrated that human liver microsomes (HLMs) can spontaneously bind to silica-coated magnetizable beads (HLM-beads) and that these HLM-beads retain uridine 5'-diphospho-glucuronosyltransferase (UGT) activity. However, the contributions of individual UGT isoforms are not directly assessable in this system except through use of model inhibitors. Thus, a preparation wherein recombinant UGT (rUGT) microsomes bound to these same beads to form rUGT-beads of individual UGT isoforms would provide a novel system for measuring the contribution of individual UGT isoforms in a direct manner. To this end, the enzyme activities and kinetic parameter estimates of various rUGT isoforms in rUGT-beads were investigated, as well as the impact of fatty acids (FAs) on enzyme activity. The catalytic efficiencies (Vmax/Km) of the tested rUGTs were twofold to sevenfold higher in rUGT-beads compared with rUGT microsomes, except for rUGT1A6, where Vmax is the maximum product formation rate normalized to milligram of microsomal protein (pmol/min/mg protein). Interestingly, in contrast to traditional rUGT preparations, the sequestration of UGT-inhibitory FA using bovine serum albumin did not alter the catalytic efficiency (Vmax/Km) of the rUGTs in rUGT-beads. Moreover, the increase in catalytic efficiency of rUGT-beads over rUGT microsomes was similar to increases in catalytic efficiency noted with rUGT microsomes (not bound to beads) incubated with bovine serum albumin, suggesting the beads in some way altered the potential for FAs to inhibit activity. The rUGT-bead system may serve as a useful albumin-free tool to determine kinetic constants for UGT substrates, particularly those that exhibit high binding to albumin.

Higher cumulative dose of topical corticosteroids is associated with osteoporosis and major osteoporotic fracture: A nationwide case-control study.

BACKGROUND: Connections between long-term use of topical corticosteroids (TCSs) of varying potency and osteoporosis and major osteoporotic fracture (MOF) are unclear. Susceptibility to adverse bone effects of TCSs in different sex, age and ethnic groups is unknown too. OBJECTIVES: To demonstrate the association between cumulative dose of TCSs of varying potency and osteoporosis and MOF in Taiwanese population, with stratified analysis of sex and age. METHODS: We conducted a nationwide case-control study and obtained data from Taiwan National Health Insurance Research Database. Cumulative TCS doses in different exposure periods were calculated, and the potency of TCSs was converted to prednisolone equivalent. Adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for osteoporosis and MOF associated with TCS use. RESULTS: From 2017 to 2020, 129,682 osteoporosis cases and 34,999 MOF cases were selected and randomly matched with 518,728 and 139,996 controls by sex and age. We found clear dose-response relationships between long-term TCS exposure and osteoporosis and MOF. For example, compared to no TCS use, adjusted ORs of osteoporosis were 1.216 (95% CI 1.189-1.243), 1.260 (95% CI, 1.241-1.280) and 1.341 (95% CI, 1.314-1.369) for exposure to low, medium and high cumulative TCS doses, respectively, over 5 years. Adjusted ORs of MOF were 1.118 (95% CI 1.069-1.170), 1.191 (95% CI, 1.156-1.227) and 1.288 (95% CI, 1.238-1.340) for exposure to low, medium and high cumulative TCS doses, respectively, over 5 years. Stratified analysis showed women had higher ORs of osteoporosis and MOF compared to men. Younger people (<50 years) had highest OR of osteoporosis compared to other age groups. CONCLUSIONS: Higher cumulative TCS dose was associated with increased risk of osteoporosis and MOF. Long-term use of TCSs should be cautious, especially in susceptible populations such as women and young people.

Pharmacokinetic-Interactions of BI 425809, a Novel Glycine Transporter 1 Inhibitor, With Cytochrome P450 and P-Glycoprotein Substrates: Findings From In Vitro Analyses and an Open-Label, Single-Sequence Phase I Study.

PURPOSE/BACKGROUND: Glycine transporter-1 inhibitors may ameliorate cognitive deficits in schizophrenia. This study evaluated potential drug-drug interactions with the glycine transporter-1 inhibitor BI 425809. METHODS/PROCEDURES: Interactions with cytochromes P450 (CYP) and P-glycoprotein (P-gp) were assessed in in vitro assays using human hepatocytes and Caco-2 cells, respectively. Pharmacokinetic characteristics of probe drugs were subsequently assessed in a Phase I, open-label, single-sequence crossover study in healthy male participants. Participants received a probe-drug cocktail containing midazolam (CYP3A4), warfarin (CYP2C9), and omeprazole (CYP2C19) and a separate dose of digoxin (P-gp), alone and on a background of steady-state BI 425809 25 mg once daily in 2 treatment periods. Adverse events were monitored. FINDINGS/RESULTS: In vitro assays revealed concentration-dependent induction of CYP3A4 and inhibition of P-gp by BI 425809. In the clinical study, 12 of 13 participants completed both periods. With BI 425809, area under the plasma concentration curve from administration to the last measurement (AUC 0-tz ) and maximum plasma concentration ( Cmax ) for midazolam were lower than when administered alone. Adjusted geometric mean ratios (90% confidence interval) were 70.6% (63.9%-78.1%) for AUC 0-tz and 77.6% (67.3%-89.4%) for Cmax . For warfarin and digoxin, AUC 0-tz and Cmax were similar with and without BI 425809. For omeprazole, BI 425809 slightly reduced AUC 0-tz but not Cmax versus omeprazole alone. No new safety signals were identified. IMPLICATIONS/CONCLUSIONS: These findings indicate induction of CYP3A4 by once-daily BI 425809 25 mg (the assumed highest therapeutic dose) and no meaningful effects on CYP2C9, CYP2C19, or P-gp in vivo.

Characterization of Divergent Metabolic Pathways in Elucidating an Unexpected, Slow-Forming, and Long Half-Life Major Metabolite of Iclepertin.

PURPOSE: After single oral dosing of the glycine reuptake transporter (GlyT1) inhibitor, iclepertin (BI 425809), a single major circulating metabolite, M530a, was identified. However, upon multiple dosing, a second major metabolite, M232, was observed with exposure levels ~ twofold higher than M530a. Studies were conducted to characterize the metabolic pathways and enzymes responsible for formation of both major human metabolites. METHODS: In vitro studies were conducted with human and recombinant enzyme sources and enzyme-selective inhibitors. The production of iclepertin metabolites was monitored by LC-MS/MS. RESULTS: Iclepertin undergoes rapid oxidation to a putative carbinolamide that spontaneously opens to an aldehyde, M528, which then undergoes reduction by carbonyl reductase to the primary alcohol, M530a. However, the carbinolamide can also undergo a much slower oxidation by CYP3A to form an unstable imide metabolite, M526, that is subsequently hydrolyzed by a plasma amidase to form M232. This difference in rate of metabolism of the carbinolamine explains why high levels of the M232 metabolite were not observed in vitro and in single dose studies in humans, but were observed in longer-term multiple dose studies. CONCLUSIONS: The long half-life iclepertin metabolite M232 is formed from a common carbinolamine intermediate, that is also a precursor of M530a. However, the formation of M232 occurs much more slowly, likely contributing to its extensive exposure in vivo. These results highlight the need to employ adequate clinical study sampling periods and rigorous characterization of unexpected metabolites, especially when such metabolites are categorized as major, thus requiring safety assessment.

Economic Burden of Atopic Dermatitis in Taiwan.

Atopic dermatitis is a prevalent inflammatory skin disease that manifests clinically as pruritus and eczema. Severe forms of atopic dermatitis can be chronic and relapsing or associated with other dermatological complications and comorbidities, resulting in lifelong impacts across multiple aspects for patients. This study was conducted to calculate the atopic dermatitis-related economic burden in Taiwan. First, the out-of- pocket costs incurred by 200 patients with atopic dermatitis were estimated using a specifically designed questionnaire. Secondly, work impairment was converted into quantifiable costs. The costs reimbursed by the Taiwan National Health Insurance (NHI), which were estimated in our previous work, were included in the final calculation. The atopic dermatitis-related economic burden for patients in Taiwan in 2018 was estimated as (2018 New Taiwan dollars; NT$) 37.90 billion, which is 0.207% of Taiwan's gross domestic product. This substantial economic burden suggests an existing need for more effective and equitable treatment for atopic dermatitis.

Taiwanese dermatological association (TDA) consensus for the management of pemphigus.

Pemphigus is an uncommon but life-threatening autoimmune blistering disease characterized by the presence of antibodies against desmogleins. Without effective treatment, pemphigus can result in significant morbidity and mortality. Existing consensus statements on pemphigus management from international medical groups provide varying guidelines, especially on treatment. Thus, on January 4, 2020, a panel of seven dermatology experts from the Taiwanese Dermatological Association (TDA) and one rheumatology expert convened to develop a consensus for the management of pemphigus. These experts with extensive experience in pemphigus management were recommended by their respective teaching hospitals and primary care clinics in Taiwan and by the TDA. The meeting reviewed the available consensus statements from international dermatology groups, including the European Dermatology Forum (EDF), the European Academy of Dermatology and Venereology (EADV), and the International Bullous Diseases Consensus Group. Using these guidelines as a basis for discussion and consensus formulation, these experts formulated their consensus statement that provides practical, concise but comprehensive recommendations as to the diagnosis, treatment, and monitoring of pemphigus patients in Taiwan. This consensus serves as a clinical reference for physicians for the management of pemphigus in Taiwan or wherever it may be applicable.

Healthcare utilization and costs of atopic dermatitis in Taiwan.

BACKGROUND: Atopic dermatitis (AD) is a common chronic skin disease. Only relatively scant studies from Asian countries have attempted to quantify AD-associated healthcare utilization and costs by using population-based databases. This study aims to evaluate the AD-associated annual healthcare utilization and costs in Taiwan. METHODS: A retrospective matched-cohort study was conducted by matching the AD cases with controls at a 1:4 (cases:controls) ratio, with the data for both the cases and controls being sourced from the 2017 National Health Insurance Research Database (NHIRD). The AD patients were stratified by disease severity based on their treatments. Differences in the regression-adjusted frequency of care and costs between the cases and controls were compared using t-tests by the severity level of AD. RESULTS: The incremental frequency of outpatient visits per year increased with AD severity (9.60, 11.28, and 16.23 for mild, moderate, and severe cases, respectively). However, the frequency of inpatient care and emergency room visits per year showed no consistent pattern associated with disease severity. The incremental total costs per year were NT$9,511.64, NT$9,705.20, and NT$15,762.09 for mild, moderate, and severe cases, respectively, and the outpatient and drug costs accounted for 46.65%-54.82% and 17.01%-31.20% of the total costs, respectively. CONCLUSION: AD was found to impose significant healthcare costs, with estimated total cost burdens of NT$3.61 billion in 2017, which is 0.314% of Taiwan's national health expenditure and 0.020% of Taiwan's gross domestic product.

The impact of atopic dermatitis on health-related quality of life in Taiwan.

BACKGROUND/PURPOSE: Atopic dermatitis (AD) is a common skin disease. At present, there is little evidence regarding its impact on patients' health-related quality of life (HRQoL) in Taiwan. Therefore, this study investigated the relationship between AD severity and patients' HRQoL in Taiwan. METHODS: Patients with AD were recruited from three hospitals in Taiwan from April 2018 to April 2019. AD severity was measured using the Scoring of AD (SCORAD) scale, and HRQoL was assessed using the Dermatology Life Quality Index (DLQI) and the five-level version of EuroQol five-dimension questionnaire (EQ-5D-5L). RESULTS: A total of 200 patients (mean age: 34.4 years) were recruited, including 103 males and 97 females. They were further classified as 79 mild, 72 moderate, and 58 severe AD patients according to their SCORAD scores. There was a positive correlation between their SCORAD and DLQI scores (Spearman's r = 0.77, p < 0.001). Patients with severe AD had higher scores in all the DLQI questions, particularly the symptoms, feelings, and work/school. In addition, both the EQ-5D visual analogue scale (VAS) scores and utility index values were negatively correlated with the SCORAD scores (Spearman's r = -0.46 and -0.60, respectively, both p < 0.001). Patients with higher AD severity had more problems with mobility, usual activity, pain/discomfort, and anxiety/depression, while demographic characteristics did not significantly affect HRQoL. CONCLUSION: Higher AD severity is associated with poorer HRQoL in Taiwanese AD patients, with AD's effects on symptoms, feelings, and work/school being the most troublesome. Meanwhile, demographic factors did not affect HRQoL significantly.

Taiwanese dermatological association consensus for the definition, classification, diagnosis, and management of urticaria: A 2021 update.

Urticaria is a prevalent disease with substantial physical, psychological, and economic impacts. With the advent of understandings of the disease and the emerging evidence of treatments, the international guidelines for treating urticaria have been updated in recent years. In order to update the 2014 edition of the Taiwanese Dermatological Association (TDA) consensus of urticaria, a total of 17 dermatologists with extensive experience in urticaria management were invited to and attended the TDA consensus meetings. All the specific aspects of the content were approved by at least 75% of the experts in attendance. Comparing to the former edition, several substantial modifications were made. For diagnosis, D-dimer was added as the recommended routine test in patients with chronic spontaneous urticaria. For pharmacological management, treatment suggestions were simplified. The approved-dosed, the up-dosed second-generation antihistamines, omalizumab, and cyclosporine were listed as the first-line to the fourth-line treatment, respectively. In addition, the management for patients of special considerations, such as the elderly, children, and pregnant women, were all discussed and mentioned in the consensus. We hope the updated TDA consensus can serve as a reference for all physicians and can help the physicians providing up-to-dated managements for these patients.

HLM-beads: Rapid Assessment of Nonspecific Binding to Human Liver Microsomes Using Magnetizable Beads.

In early drug development, drug-drug interaction risk is routinely assessed using human liver microsomes (HLMs). Nonspecific binding of drugs to HLMs can affect the determination of accurate enzyme parameters (Km, Ki, KI). Previously, we described a novel in vitro model consisting of HLMs bound to magnetizable beads [HLM-magnetizable-beads system (HLM-beads)]. The HLM-beads enable rapid separation of HLMs from incubation media by applying a magnetic field. Here, HLM-beads were further characterized and evaluated as a tool to assess HLM nonspecific binding of small molecules. The free fractions (fu,mic) of 13 compounds (chosen based on their pKa values) were determined using HLM-beads under three HLM concentrations (0.025, 0.50, and 1.0 mg/ml) and compared with those determined by equilibrium dialysis. Most fu,mic values obtained using HLM-beads were within 0.5- to 2-fold of the values determined using equilibrium dialysis. The highest fold difference were observed for high binders itraconazole and BIRT2584 (1.9- to 2.9-fold), as the pronounced adsorption of these compounds to the equilibrium dialysis apparatus interfered with their fu,mic determination. Correlation and linear regression analysis of the fu,mic values generated using HLM-beads and equilibrium dialysis was conducted. Overall, a good correlation of fu,mic values obtained by the two methods were observed, as the r and R2 values from correlational analysis and linear regression analysis were >0.9 and >0.89, respectively. These studies demonstrate that HLM-beads can produce comparable fu,mic values as determined by equilibrium dialysis while reducing the time required for this type of study from hours to only 10 minutes and compound apparatus adsorption. SIGNIFICANCE STATEMENT: This work introduces a new method of rapidly assessing nonspecific microsomal binding using human liver microsomes bound to magnetizable beads.

Network meta-analysis-based comparison of first-line steroid-sparing adjuvants in the treatment of pemphigus vulgaris and pemphigus foliaceus.

BACKGROUND: Steroid-sparing adjuvants may enhance oral glucocorticoid benefits in pemphigus treatment. Selecting the optimal therapeutic option among various first-line steroid-sparing adjuvants is often a clinical challenge due to the lack of head-to-head clinical trials. OBJECTIVE: To determine the best first-line steroid-sparing adjuvants for pemphigus treatment. METHODS: Randomized controlled trials comparing different steroid-sparing adjuvants in patients with pemphigus were identified through a systematic literature search and subjected to a network meta-analysis. The primary outcomes were the proportion of remission and the mean cumulative glucocorticoid dose. RESULTS: Ten trials involving 592 patients were analyzed. Among the 7 steroid-sparing adjuvants evaluated, rituximab was the most effective for achieving remission and was more effective than steroid alone (odds ratio, 14.35; 95% confidence interval [CI], 4.71-43.68). Rituximab, azathioprine, and cyclophosphamide pulse therapy enabled the reduction of the cumulative glucocorticoid doses compared to the use of steroid alone: mean differences, -11,830.5 mg (95% CI, -14,089.48 to -9571.52), -3032.48 mg (-4700.74 to -1364.22), and -2469.54 mg (-4128.42 to -810.66), respectively. LIMITATIONS: The results were driven primarily by a small number of studies, and the effect estimates are imprecise because of indirect comparisons. CONCLUSION: Network meta-analysis showed that rituximab appears to be an efficacious, well tolerated steroid-sparing adjuvant for pemphigus.

Impact of Atopic Dermatitis on Work and Activity Impairment in Taiwan.

Atopic dermatitis has a substantial impact on work and activity impairment according to studies from Western communities. Prospective studies of work productivity and activity impairment in Asian patients with atopic dermatitis are lacking. The aims of this study were to investigate the impacts of atopic dermatitis on work productivity and activity impairment among Taiwanese patients, and to stratify the analyses by disease severity. One-third of employed participants reported missing work (absenteeism) in the preceding week due to atopic dermatitis, while 88.5% of the remaining two-thirds reported impaired work effectiveness (presenteeism). In addition, 92.5% of all participants reported impaired daily activities. Overall work impairment (aggregate productivity loss from absenteeism and presenteeism) was 1.8- and 2.6-fold greater in subjects with moderate and severe atopic dermatitis, respectively, compared with those with mild atopic dermatitis. Presenteeism, but not absenteeism, contributes to the majority of total work impairment in this cohort. Daily activity impairment was 1.5-fold greater in moderate atopic dermatitis, and 2.0-fold greater in severe atopic dermatitis, compared with mild atopic dermatitis. Both work and activity impairment showed significant positive correlations with atopic dermatitis severity scores (SCORing Atopic Dermatitis; SCORAD). In conclusion, work productivity and activity impairment is significantly correlated with disease severity in this Taiwanese atopic dermatitis cohort. In order to obtain a full picture of disease burden to patients and caregivers, patients with atopic dermatitis should be monitored for disease activity as well as corresponding impacts on quality of life.

Taiwanese Dermatological Association consensus for the management of atopic dermatitis: A 2020 update.

BACKGROUND/PURPOSE: Atopic dermatitis (AD) is a chronic inflammatory disease commonly seen in children and increasingly recognized in adults. With recent advances in the therapeutic development for AD, the Taiwanese Dermatological Association (TDA) established a committee to update the consensus for AD management in Taiwan. This report describes the 2020 updated consensus for the management of AD. METHODS: A panel of 11 core members was convened to review and discuss aspects of AD management and draft recommendation during the first two meetings. The 2015 TDA consensus and the 2017 European guideline, along with recent peer-reviewed articles, serve as the foundation for the update. In the third meeting, AD expert dermatologists selected on a national scale were invited to vote on the final statements. A total of 27 dermatologists attended the final meeting. The consensus was achieved when ratings of 7-9 (out of a total score of 9) accounted for ≥ 75% of the total votes. RESULTS: Consensus was achieved on the therapeutic options for AD by lines of treatment. A treatment algorithm was presented to illustrate the place of each modality in terms of basic care, acute disease control, and maintenance therapy. Special considerations for the pediatric population, as well as for women during pregnancy and lactation, are discussed. CONCLUSION: Topical corticosteroids with long-term emollient-based therapies remain the cornerstone of AD treatment. Systemic treatments are indicated when topical therapies and phototherapy fail to control the disease. The recent approval of dupilumab and emerging targeted therapies are expected to bring significant clinical benefit for patients whose disease is inadequately managed by existing options.

Evaluation of Erythromycin as a Tool to Assess CYP3A Contribution of Low Clearance Compounds in a Long-Term Hepatocyte Culture.

Long-term hepatocyte culture systems such as HepatoPac are well suited to evaluate the metabolic turnover of low clearance (CL) drugs because of their sustained metabolic capacity and longer-term viability. Erythromycin (ERY), a moderate, mechanism-based inhibitor of CYP3A, was evaluated as a tool in the HepatoPac model to assess contribution of CYP3A to the clearance of drug candidates. ERY inhibited CYP3A activity by 58% and 80% at 3 and 10 µM, respectively, for up to 72 hours. At 30 µM, ERY inhibited midazolam hydroxylation by >85% for the entire 144-hour duration of the incubation. Alprazolam CLint was inhibited 58% by 3 µM of ERY, 75% by 15 µM of ERY, 89% by 30 µM of ERY, and 94% by 60 µM of ERY. ERY (30 µM) did not markedly affect CLint of substrates for several other major cytochrome P450 isoforms evaluated and did not markedly inhibit uridine diphosphoglucuronosyl transferase (UGT) isoforms 1A1, 1A3, 1A4, 1A6, 1A9, 2B7, or 2B15 as assessed using recombinant UGTs. ERY only mildly increased CYP3A4 gene expression by 2.1-fold (14% of rifampicin induction) at 120 µM, indicating that at effective concentrations for inhibition of CYP3A activity (30-60 µM), arylhydrocarbon receptor, constitutive androstane receptor, and pregnane-X-receptor activation are not likely to markedly increase levels of other drug-metabolizing enzymes or transporters. ERY at concentrations up to 60 µM was not toxic for up to 6 days of incubation. Use of ERY to selectively inhibit CYP3A in high-functioning, long-term hepatocyte models such as HepatoPac can be a valuable strategy to evaluate the contribution of CYP3A metabolism to the overall clearance of slowly metabolized drug candidates. SIGNIFICANCE STATEMENT: This work describes the use of erythromycin as a selective inhibitor of CYP3A to assess the contribution of CYP3A in the metabolism of compounds using long-term hepatocyte cultures.

Human Liver Microsomes Immobilized on Magnetizable Beads: A Novel Approach to Study In Vitro Drug Metabolism.

Human liver microsomes (HLM) are a commonly used tool to study drug metabolism in vitro. Typical experiments conducted using suspensions of HLM can be challenging to separate from the incubation solution without lengthy ultracentrifugation steps. Magnetizable beads coated with silica (MGBS) were found to bind strongly to HLM, which could then be isolated and purified using a magnet. Binding of HLM to the MGBS (HLM-MGBS) was demonstrated to be mediated by strong interactions between microsomal phospholipids and MGBS, as artificially prepared phosphatidylcholine (PC) liposomes could be more efficiently captured by the MGBS. HLM-MGBS complexes retained functional cytochrome P450 and uridine-diphosphate-glucuronosyltransferase (UGT) activity as indicated by CYP2C8-mediated amodiaquine de-ethylation, CYP3A4-mediated midazolam 1'hydroxylation, UGT1A1-mediated glucuronidation of estradiol, UGT1A9-mediated glucuronidation of propofol, and UGT2B7-mediated glucuronidation of zidovudine. When comparing suspension HLM alone with HLM-MGBS complexes containing equivalent amounts of HLM, the intrinsic clearance (CLint) of CYP450 substrates was comparable; however, CLint of UGT1A1, UGT1A9, and UGT2B7 was increased in the HLM-MGBS system between 1.5- and 6-fold. HLM-MGBS used in an incubation could also be readily replaced with fresh HLM-MGBS to maintain the presence of active enzymes. Thus, HLM-MGBS demonstrate increased in vitro metabolic efficiency and manipulability, providing a new platform for determination of accurate metabolic parameters. SIGNIFICANCE STATEMENT: The following work describes the strong binding of HLM to magnetizable beads. In addition, the preservation of enzyme activity on the bound HLM provides a novel means to conduct preclinical metabolism studies.

Discovery of the IL-23/IL-17 Signaling Pathway and the Treatment of Psoriasis.

Psoriasis vulgaris is a common, heterogeneous, chronic inflammatory skin disease characterized by thickened, red, scaly plaques and systemic inflammation. Psoriasis is also associated with multiple comorbid conditions, such as joint destruction, cardiovascular disease, stroke, hypertension, metabolic syndrome, and chronic kidney disease. The discovery of IL-17-producing T cells in a mouse model of autoimmunity transformed our understanding of inflammation driven by T lymphocytes and associations with human inflammatory diseases, such as psoriasis. Under the regulation of IL-23, T cells that produce high levels of IL-17 create a self-amplifying, feed-forward inflammatory response in keratinocytes that drives the development of thickened skin lesions infiltrated with a mixture of inflammatory cell populations. Recently, the Food and Drug Administration approved multiple highly effective psoriasis therapies that disrupt IL-17 (secukinumab, ixekizumab, and brodalumab) and IL-23 (guselkumab and tildrakizumab) signaling in the skin, thus leading to a major paradigm shift in the way that psoriatic disease is managed.

Meeting the Challenge of Predicting Hepatic Clearance of Compounds Slowly Metabolized by Cytochrome P450 Using a Novel Hepatocyte Model, HepatoPac.

Generating accurate in vitro intrinsic clearance data is an important aspect of predicting in vivo human clearance. Primary hepatocytes in suspension are routinely used to predict in vivo clearance; however, incubation times have typically been limited to 4-6 hours, which is not long enough to accurately evaluate the metabolic stability of slowly metabolized compounds. HepatoPac is a micropatterened hepatocyte-fibroblast coculture system that can be used for continuous incubations of up to 7 days. This study evaluated the ability of human HepatoPac to predict the in vivo clearance (CL) of 17 commercially available compounds with low to intermediate clearance (<12 ml/min/kg). In vitro half-life for disappearance of each compound was converted to hepatic clearance using the well stirred model, with and without correction for plasma protein binding. Hepatic CL, using three individual donors, was accurately predicted for 11 of 17 compounds (59%; predicted clearance within 2-fold of observed human in vivo clearance values). The accuracy of prediction increased to 82% (14 of 17 compounds) with an acceptance criterion defined as within 3-fold. When considering only low clearance compounds (<5 ml/min per kg), which represented 10 of the 17 compounds, the accuracy of prediction was 70% within 2-fold and 100% within 3-fold. In addition, the turnover of three slowly metabolized compounds (alprazolam, meloxicam, and tolbutamide) in HepatoPac was directly compared with turnover in suspended hepatocytes. The turnover of alprazolam and tolbutamide was approximately 2-fold greater using HepatoPac compared with suspended hepatocytes, which was roughly in line with the extrapolated values (correcting for the longer incubation time and lower cell number with HepatoPac). HepatoPac, but not suspended hepatocytes, demonstrated significant turnover of meloxicam. These results demonstrate the utility of HepatoPac for prediction of in vivo hepatic clearance, particularly with low clearance compounds.

Atopic dermatitis in African American patients is TH2/TH22-skewed with TH1/TH17 attenuation.

BACKGROUND: African Americans (AA) are disproportionately impacted by atopic dermatitis (AD), with increased prevalence and therapeutic challenges unique to this population. Molecular profiling data informing development of targeted therapeutics for AD are derived primarily from European American (EA) patients. These studies are absent in AA, hindering development of effective treatments for this population. OBJECTIVE: We sought to characterize the global molecular profile of AD in the skin of AA patients as compared with that of EA AD and healthy controls. METHODS: We performed RNA-Seq with reverse transcription polymerase chain reaction validation and immunohistochemistry studies in lesional and nonlesional skin of AA and EA AD patients vs healthy controls. RESULTS: African American AD lesions were characterized by greater infiltration of dendritic cells (DCs) marked by the high-affinity immunoglobulin E (IgE) receptor (FcεR1+) compared with EA AD (P < .05). Both AD cohorts showed similarly robust up-regulation of Th2-related (CCL17/18/26) and Th22-related markers (interleukin [IL]-22, S100A8/9/12), but AA AD featured decreased expression of innate immune (tumor necrosis factor [TNF], IL-1ß), Th1-related (interferon gamma [IFN-γ], MX1, IL-12RB1), and Th17-related markers (IL-23p19, IL-36G, CXCL1) vs EA AD (P < .05). The Th2 (IL-13) and Th22-related products (IL-22, S100A8/9/12) and serum IgE were significantly correlated with clinical severity (Scoring of Atopic Dermatitis [SCORAD]) in AA. Fillagrin (FLG) was exclusively down-regulated in EA AD, whereas loricrin (LOR) was down-regulated in both AD cohorts and negatively correlated with SCORAD in AA. CONCLUSION: The molecular phenotype of AA AD skin is characterized by attenuated Th1 and Th17 but similar Th2/Th22-skewing to EA AD. Our data encourages a personalized medicine approach accounting for phenotype-specific characteristics in future development of targeted therapeutics and clinical trial design for AD.

Effect of short-term liver X receptor activation on epidermal barrier features in mild to moderate atopic dermatitis: A randomized controlled trial.

BACKGROUND: Liver X receptors (LXRs) are involved in maintaining epidermal barrier and suppressing inflammatory responses in model systems. The LXR agonist VTP-38543 showed promising results in improving barrier function and inflammatory responses in model systems. OBJECTIVE: To assess the safety, tolerability, cellular and molecular changes, and clinical efficacy of the topical VTP-38543 in adults with mild to moderate atopic dermatitis (AD). METHODS: A total of 104 ambulatory patients with mild to moderate AD were enrolled in this randomized, double-blind, vehicle-controlled trial between December 2015 and September 2016. VTP-38543 cream in 3 concentrations (0.05%, 0.15%, and 1.0%) or placebo was applied twice daily for 28 days. Pretreatment and posttreatment skin biopsy specimens were obtained from a subset of 33 patients. Changes in SCORing of Atopic Dermatitis, Eczema Area and Severity Index, Investigator's Global Assessment, and tissue biomarkers (by real-time polymerase chain reaction and immunostaining) were evaluated. RESULTS: Topical VTP-38543 was safe and well tolerated. VTP-38543 significantly increased messenger RNA (mRNA) expression of epidermal barrier differentiation (loricrin and filaggrin, P = .02) and lipid (adenosine triphosphate-binding cassette subfamily G member 1 and sterol regulatory element binding protein 1c, P < .01) measures and reduced epidermal hyperplasia markers (thickness, keratin 16 mRNA). VTP-38543 nonsignificantly suppressed cellular infiltrates and down-regulated mRNA expression of several TH17/TH22-related (phosphatidylinositol 3, S100 calcium-binding protein A12) and innate immunity (interleukin 6) markers. CONCLUSION: Topical VTP-38543 is safe and well tolerated. Its application led to improvement in barrier differentiation and lipids. Longer-term studies are needed to clarify whether a barrier-based approach can induce meaningful suppression of immune abnormalities. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT02655679.