Application of microphysiological systems for nonclinical evaluation of cell therapies

Microphysiological systems (MPS) are gaining broader application in the pharmaceutical industry but have primarily been leveraged in early discovery toxicology and pharmacology studies with small molecules. The adoption of MPS offers a promising avenue to reduce animal use, improve in-vitro-to-in-vivo translation of pharmacokinetics/pharmacodynamics and toxicity correlation, and provide mechanistic understanding of model species suitability. While MPS have demonstrated utility in these areas with small molecules and biologics, MPS models in cell therapy development have not been fully explored, let alone validated. Distinguishing features of MPS, including long-term viability and physiologically relevant expression of functional enzymes, receptors, and pharmacological targets make them attractive tools for nonclinical characterization. However, there is currently limited published evidence of MPS being utilized to study the disposition, metabolism, pharmacology, and toxicity profiles of cell therapies. This review provides an industry perspective on the nonclinical application of MPS on cell therapies, first with a focus on oncology applications followed by examples in regenerative medicine.

Microphysiological systems (MPS) are advanced cell models, applied in the pharmaceutical industry to characterize novel therapies. While their application in studies of small molecule ther­apies has been very successful, the use of these models to study cell therapies has been limited. Cell therapies consist of cells and are living drugs, often with complex biological mechanisms of action, which can be very challenging to study. However, MPS have several features that make them attractive for studying cell therapies, including possibilities for longer-term studies and the ability to mimic physiologically relevant biological functions. MPS can mimic complex biological systems and processes, as such, the adoption of MPS offers a promising avenue to reduce the use of animals in the characterization of novel therapies. This review provides an industry perspective on current chal­lenges and highlights opportunities for using MPS in the development of cell therapies.

Comparison of Commonly Used and New Methods to Determine Small Molecule Non-Specific Binding to Human Liver Microsomes.

Accurate measurement of non-specific binding of a drug candidate to human liver microsomes (HLM) can be critical for the accurate determination of key enzyme kinetic parameters such as Michaelis-Menton (Km), reversible inhibition (Ki), or inactivation (KI) constants. Several methods have been developed to determine non-specific binding of small molecules to HLM, such as rapid equilibrium dialysis (RED), ultrafiltration (UF), HLM bound to magnetizable beads (HLM-beads), ultracentrifugation (UC), the linear extrapolation stability assay (LESA), and the Transil™ system. Despite various differences in methodology between these methods, it is generally presumed that similar free fraction values (fu,mic) should be generated. To evaluate this hypothesis, a test set of 9 compounds were selected, representing low (high fu,mic value) and significant (low fu,mic value) HLM binding, respectively, across HLM concentrations tested in this manuscript. The fu,mic values were determined using a single compound concentration (1.0 µM) and three HLM concentrations (0.025, 0.50, and 1.0 mg/mL). When the HLM non-specific binding event is not extensive resulting in high fu,mic values, all methods generated similar fu,mic values. However, fu,mic values varied markedly across assay formats when high binding to HLM occurred, where fu,mic values differed by up to 33-fold depending on the method used. Potential causes for such discrepancies across the various methods employed, practical implications related to conduct the different assays, and implications to clinical drug-drug interaction (DDI) predictions are discussed.

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.

Considerations from an International Regulatory and Pharmaceutical Industry (IQ MPS Affiliate) Workshop on the Standardization of Complex In Vitro Models in Drug Development.

In May 2022, there is an International Regulatory and Pharmaceutical Industry (Innovation and Quality [IQ] Microphysiological Systems [MPS] Affiliate) Workshop on the standardization of complex in vitro models (CIVMs) in drug development. This manuscript summarizes the discussions and conclusions of this joint workshop organized and executed by the IQ MPS Affiliate and the United States Food and Drug Administration (FDA). A key objective of the workshop is to facilitate discussions around opportunities and/or needs for standardization of MPS and chart potential pathways to increase model utilization in the context of regulatory decision making. Participation in the workshop included 200 attendees from the FDA, IQ MPS Affiliate, and 26 global regulatory organizations and affiliated parties representing Europe, Japan, and Canada. It is agreed that understanding global perspectives regarding the readiness of CIVM/MPS models for regulatory decision making and potential pathways to gaining acceptance is useful to align on globally. The obstacles are currently too great to develop standards for every context of use (COU). Instead, it is suggested that a more tractable approach may be to think of broadly applicable standards that can be applied regardless of COU and/or organ system. Considerations and next steps for this effort are described.

Association Between the Use of Topical Calcineurin Inhibitors and the Risk of Cancer Among Patients with Atopic Dermatitis: A Nationwide, Population-Based, Retrospective Cohort Study.

IMPORTANCE: The cancer risks associated with treatment with topical calcineurin inhibitors (TCIs) in patients with atopic dermatitis (AD) remain controversial, and limited evidence exists regarding the cancer risks among patients with AD treated with TCIs in Asian populations. OBJECTIVES: This study identified the association between TCI use and the risks of developing all cancers, lymphoma, skin cancers, and other cancers. DESIGN: This study was a nationwide, population-based, retrospective cohort study. SETTING: Taiwan's National Health Insurance Research Database. PARTICIPANTS: Patients diagnosed at least twice with ICD-9 code 691 or at least one time with ICD-9 codes 691 or 692.9 within 1 year between 1 January 2003 and 31 December 2010 were included and followed until 31 December 2018. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using the Cox proportional hazard ratio model. EXPOSURES: Patients using tacrolimus or pimecrolimus were identified in the National Health Insurance Research Database and compared with patients using topical corticosteroids (TCSs). MAIN OUTCOMES AND MEASURES: The main outcomes were hazard ratios (HRs) of cancer diagnoses and associated outcomes obtained from the Taiwan Cancer Registry database. RESULTS: After propensity score (PS) matching, the final cohort included 195,925 patients with AD, including 39,185 who were initial TCI users and 156,740 who were TCS users. Propensity score matching was performed according to age, sex, index year, and Charlson Comorbidity Index using a ratio of 1:4. Except for leukemia, HR and 95% CI showed no significant associations between TCI use and the risk of developing all cancer, lymphoma, skin cancers, and other cancers. Sensitivity analysis showed that the lag time HRs for every cancer subtype continued to show no significant association between TCI use and cancer risk, except for leukemia. CONCLUSIONS AND RELEVANCE: Our study found no evidence to support an association between TCI use and the risks of almost all cancers compared with TCS use in patients with AD, but physicians should be aware of potentially higher risks of leukemia with TCI use. This study represents the first population-based study focused on the cancer risk of TCI use among patients with AD in an Asian population.

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.

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.

Step-Wise Management of Anemia in Patients With Chronic Kidney Disease in Primary Care: Qualitative Study.

INTRODUCTION: Anemia is common in chronic kidney disease (CKD) and is associated with increased cardiovascular risk and reduced quality of life, but is often sub-optimally managed. Most patients are managed in primary care alongside other comorbidities. Interventions to improve the management of anemia in CKD in this setting are needed. METHODS: We conducted a qualitative study to evaluate how an audit-based education (ABE) intervention might improve the management of anemia in CKD. We explored outcomes that would be relevant to practitioners and patients, that exposed variation of practice from National Institute for Health and Care Excellence (NICE) guidelines, and whether the intervention was feasible and acceptable. RESULTS: Practitioners (n = 5 groups) and patients (n = 7) from 4 London general practices participated in discussions. Practitioners welcomed the evidence-based step-wise intervention. However, prescribing erythropoiesis-stimulating agents (ESAs) was felt to be outside of their scope of practice. There was a gap between NICE guidance and clinical practice in primary care. Iron studies were not well understood and anemia management was often conservative or delayed. Patients were often unaware of having CKD, and were more concerned about their other comorbidities, but largely trusted their GPs to manage them appropriately. CONCLUSIONS: The first steps of the intervention were welcomed by practitioners, but they expressed concerns about independently prescribing ESAs. Renal physicians and GPs could develop shared care protocols for ESA use in primary care. There is scope to improve awareness of renal anemia, and enhance knowledge of guideline recommendations; and our intervention should be modified accordingly.

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.

Efficacy of Dupilumab on Different Phenotypes of Adult with Moderate-to-Severe Atopic Dermatitis in Taiwan: A Real-World Study.

To determine phenotype-related dupilumab response in adult patients with atopic dermatitis (AD), this multicenter, retrospective study included 111 adults with moderate-to-severe AD in Taiwan, with median age of 31.5 years (18-87) and 71 (64.0%) males. Patients received dupilumab 300 mg per two to three weeks up to 12 months. We found a significant improvement after 4 and 16 weeks of treatment in all patients for all the assessed scores, including eczema area and severity index (EASI) improvement ≥50% (EASI-50) and 75% (EASI-75), EASI reaching minimal clinically important difference (MCID), and Investigator's Global Assessment (IGA) improvement ≥2. Importantly, prior to asthma, early AD onset and 3-week drug intervals were significantly associated with a high proportion of EASI-75 at month 12, while prurigo and lichenoid phenotypes were associated with a lower proportion of EASI-75 at month 12. However, the majority of adverse events were mild in severity. In conclusion, our study results identify phenotype-related dupilumab response at month 12 in adults with moderate-to-severe AD, and we suggest that treatment should not be discontinued until reaching a satisfactory clinical response.

Correlation between anxiety and depression risk and atopic dermatitis severity in Taiwan: A cross-sectional study.

BACKGROUND: Limited studies on atopic dermatitis (AD) have investigated the possible covariance of sociodemographic factors with the Hospital Anxiety and Depression Scale (HADS). OBJECTIVE: This study aimed to examine the possible covariance between AD severity and HADS scores of patients in Taiwan. METHODS: Patients with AD from a medical center and 2 regional hospitals in Taiwan were enrolled in this cross-sectional study from April 2018 to April 2019. AD severity was measured using the "scoring atopic dermatitis" index, and anxiety and depression were screened based on HADS. RESULTS: A total of 200 patients were included. After correcting for sociodemographic variables, significantly more borderline (≥8) and abnormal (≥11) cases of anxiety/depression (P < .05) were noted in patients with moderate-to-severe AD. LIMITATIONS: First, the cross-sectional study design cannot show causality. Second, baseline data, including a history of underlying cancer or previous psychiatric disorder, were not obtained in the questionnaire and may confound the HADS scores. Finally, a standardized psychiatric clinical interviews study design should be used for higher accuracy in the assessment of psycho-comorbidities. CONCLUSION: Higher anxiety and depression risks were noted in patients with moderate-to-severe AD. Except for psychosomatic symptoms, all kinds of anxiety and depression symptoms occurred more frequently in patients with moderate-to-severe AD.

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.

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.