Tool For Drug Development Research Articles

Triiodothyronine and dexamethasone alter potassium channel expression and promote electrophysiological maturation of human-induced pluripotent stem cell-derived cardiomyocytes

BackgroundHuman-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have emerged as a promising tool for disease modeling and drug development. However, hiPSC-CMs remain functionally immature, which hinders their utility as a model of human cardiomyocytes. ObjectiveTo improve the electrophysiological maturation of hiPSC-CMs. Methods and resultsOn day 16 of cardiac differentiation, hiPSC-CMs were treated with 100 nmol/L triiodothyronine (T3) and 1 μmol/L Dexamethasone (Dex) or vehicle for 14 days. On day 30, vehicle- and T3 + Dex-treated hiPSC-CMs were dissociated and replated either as cell sheets or single cells. Optical mapping and patch-clamp technique were used to examine the electrophysiological properties of vehicle- and T3 + Dex-treated hiPSC-CMs. Compared to vehicle, T3 + Dex-treated hiPSC-CMs had a slower spontaneous beating rate, more hyperpolarized resting membrane potential, faster maximal upstroke velocity, and shorter action potential duration. Changes in spontaneous activity and action potential were mediated by decreased hyperpolarization-activated current (If) and increased inward rectifier potassium currents (IK1), sodium currents (INa), and the rapidly and slowly activating delayed rectifier potassium currents (IKr and IKs, respectively). Furthermore, T3 + Dex-treated hiPSC-CM cell sheets (hiPSC-CCSs) exhibited a faster conduction velocity and shorter action potential duration than the vehicle. Inhibition of IK1 by 100 μM BaCl2 significantly slowed conduction velocity and prolonged action potential duration in T3 + Dex-treated hiPSC-CCSs but had no effect in the vehicle group, demonstrating the importance of IK1 for conduction velocity and action potential duration. ConclusionT3 + Dex treatment is an effective approach to rapidly enhance electrophysiological maturation of hiPSC-CMs.

Engineering mechanobiology through organoids-on-chip: Astrategy to boost therapeutics.

The mechanical environment of living cells is as critical as chemical signaling. Mechanical stimuli play a pivotal role in organogenesis and tissue homeostasis. Unbalances in mechanotransduction pathways often lead to diseases, such as cancer, cystic fibrosis, and neurodevelopmental disorders. Despite its inherent relevance, there is a lack of proper mechanoresponsive in vitro study systems. In this context, there is an urge to engineer innovative, robust, dynamic, and reliable organotypic technologies to better connect cellular processes to organ-level function and multi-tissue cross-talk. Mechanically active organoid-on-chip has the potential to surpass this challenge. These systems converge microfabrication, microfluidics, biophysics, and tissue engineering fields to emulate key features of living organisms, hence, reducing costs, time, and animal testing. In this review, we intended to present cutting-edge organ-on-chip platforms that integrate biomechanical stimuli as well as novel multicellular culture, such as organoids. We focused on its application in two main fields: precision medicine and drug development. Moreover, we also discussed the state of the art for the development of an engineered model to assess patient-derived tumor organoid metastatic potential. Finally, we highlighted the current drawbacks and emerging opportunities to match the industry needs. We envision the use of mechanoresponsive organotypic-on-chip microdevices as an indispensable tool for precision medicine, drug development, disease modeling, tissue engineering, and developmental biology.

Survival-Assured Liver Injury Preconditioning (SALIC) Enables Robust Expansion of Human Hepatocytes in Fah-/- Rag2-/- IL2rg-/- Rats.

Although liver‐humanized animals are desirable tools for drug development and expansion of human hepatocytes in large quantities, their development is restricted to mice. In animals larger than mice, a precondition for efficient liver humanization remains preliminary because of different xeno‐repopulation kinetics in livers of larger sizes. Since rats are ten times larger than mice and widely used in pharmacological studies, liver‐humanized rats are more preferable. Here, Fah–/–Rag2–/–IL2rg–/– (FRG) rats are generated by CRISPR/Cas9, showing accelerated liver failure and lagged liver xeno‐repopulation compared to FRG mice. A survival‐assured liver injury preconditioning (SALIC) protocol, which consists of retrorsine pretreatment and cycling 2‐(2‐nitro‐4‐trifluoromethylbenzoyl)‐1,3‐cyclohexanedione (NTBC) administration by defined concentrations and time intervals, is developed to reduce the mortality of FRG rats and induce a regenerative microenvironment for xeno‐repopulation. Human hepatocyte repopulation is boosted to 31 ± 4% in rat livers at 7 months after transplantation, equivalent to approximately a 1200‐fold expansion. Human liver features of transcriptome and zonation are reproduced in humanized rats. Remarkably, they provide sufficient samples for the pharmacokinetic profiling of human‐specific metabolites. This model is thus preferred for pharmacological studies and human hepatocyte production. SALIC may also be informative to hepatocyte transplantation in other large‐sized species.

Anti-inflammatory Compounds from the Hydrolysate of Indian Marine Green Mussel (Perna viridis L)

Natural products offer a great hope in identifying bioactive compounds and their development into drugs to treat several diseases including inflammatory problems. Ocean has been considered as a rich source of such compounds with novel structures and important biological activities. Traditional medicine is widespread and natural compounds represent a large source of naturally occurring secondary metabolites that might lead to novel drugs. The ocean also offers the potential for producing metabolites, which may be different from the terrestrial organisms. Due to the complex nature and dynamic system in the ocean, the marine organisms have developed unique metabolic and physiologic capabilies that ensure their survival in extreme variations of pressure, salinity and temperature. Marine organisms, including mussel, have produced a variety of chemically interesting and biologically significant secondary metabolites. Some are expected to serve as lead compounds for drug development or pharmacological tools for basic life science studies. Marine animals can survive in an inimical environment surrounded by various pathogenic organisms, including human pathogens. They are also potential sources for bioactive compounds as observed in edible bivalves, such as Meretrix casta (Chemnitz), Polymesoda (Geloina) Polymesoda erosa (Solander), Perna viridis (Linnaeus), Crassostrea gryphoides (Schlothim), and Villorita cyprinoides (Grey). Recent studies conducted have shown that green mussels are an inexpensive source of protein for human consumption and possess some important complex potential bioactive compounds useful as medicines. Isolation of bioactive compounds like anti-inflammatory from marine sources has been receiving special attention among natural bioactive compounds because of their economic significance effectiveness and the increasing incidents of drug resistance lead to difficulties in the pharmacological field. The present study reviewed the anti-inflammatory compounds from the hydrolysate prepared from green mussel which will be identified and characterized for commercial use.

Rapid and Sensitive Inhibitor Screening Using Magnetically Modulated Biosensors.

Inhibitor screening is an important tool for drug development, especially during the COVID-19 pandemic. The most used in vitro inhibitor screening tool is an enzyme-linked immunosorbent assay (ELISA). However, ELISA-based inhibitor screening is time consuming and has a limited dynamic range. Using fluorescently and magnetically modulated biosensors (MMB), we developed a rapid and sensitive inhibitor screening tool. This study demonstrates its performance by screening small molecules and neutralizing antibodies as potential inhibitors of the interaction between the spike protein 1 (S1) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the angiotensin-converting enzyme 2 (ACE2) receptor. The MMB-based assay is highly sensitive, has minimal non-specific binding, and is much faster than the commonly used ELISA (2 h vs. 7–24 h). We anticipate that our method will lead to a remarkable advance in screening for new drug candidates.

Utilizing feline oral squamous cell carcinoma patients to develop NQO1-targeted therapy

Developing effective therapies for the treatment of advanced head-and-neck squamous cell carcinoma (HNSCC) remains a major challenge, and there is a limited landscape of effective targeted therapies on the horizon. NAD(P)H:quinone oxidoreductase 1 (NQO1) is a 2-electron reductase that is overexpressed in HNSCC and presents as a promising target for the treatment of HNSCC. Current NQO1-targeted drugs are hindered by their poor oxidative tolerability in human patients, underscoring a need for better preclinical screening for oxidative toxicities for NQO1-bioactivated small molecules. Herein, we describe our work to include felines and feline oral squamous cell carcinoma (FOSCC) patients in the preclinical assessment process to prioritize lead compounds with increased tolerability and efficacy prior to full human translation. Specifically, our data demonstrate that IB-DNQ, an NQO1-targeted small molecule, is well-tolerated in FOSCC patients and shows promising initial efficacy against FOSCC tumors in proof-of-concept single agent and radiotherapy combination cohorts. Furthermore, FOSCC tumors are amenable to evaluating a variety of target-inducible couplet hypotheses, evidenced herein with modulation of NQO1 levels with palliative radiotherapy. The use of felines and their naturally-occurring tumors provide an intriguing, often underutilized tool for preclinical drug development for NQO1-targeted approaches and has broader applications for the evaluation of other anticancer strategies.

The Deuterated "Magic Methyl" Group: A Guide to Site-Selective Trideuteromethyl Incorporation and Labeling by Using CD3 Reagents.

In the field of medicinal chemistry, the precise installation of a trideuteromethyl group is gaining ever‐increasing attention. Site‐selective incorporation of the deuterated “magic methyl” group can provide profound pharmacological benefits and can be considered an important tool for drug optimization and development. This review provides a structured overview, according to trideuteromethylation reagent, of currently established methods for site‐selective trideuteromethylation of carbon atoms. In addition to CD3, the selective introduction of CD2H and CDH2 groups is also considered. For all methods, the corresponding mechanism and scope are discussed whenever reported. As such, this review can be a starting point for synthetic chemists to further advance trideuteromethylation methodologies. At the same time, this review aims to be a guide for medicinal chemists, offering them the available C−CD3 formation strategies for the preparation of new or modified drugs.

Abstract 2954: Humanized CCR8 mouse model provides a translational tool for anti-human CCR8 antibody drug development

Abstract CCR8 is reported as an important chemokine receptor expressed on intra-tumoral Tregs and plays a critical role in CCR8+Treg-mediated immunosuppression via inducing STAT3-dependent overexpression of FOXP3, CD39, IL-10, and granzyme B on Tregs with interaction of CCL1 (CCR8 ligand). CCR8 becomes a promising target in the anticancer drug development. Generation of humanized CCR8 mouse model can greatly improve translation and accelerate CCR8-related drug development. To evaluate the anti-tumor efficacy of human CCR8 blockade in tumor mouse models, Biocytogen has successfully generated a novel CCR8 humanized knock-in mouse strain to support anti-human CCR8 antibody drug development. In this mouse model, the full length of encoding sequences of mouse CCR8 gene were replaced by the full length of encoding sequences of human CCR8 (hCCR8) gene. CCR8 gene expression in WT and B-hCCR8 mice were tested by RT-PCR. Human CCR8 mRNA was detected in hCCR8 mice model but not in wild-type mice. Protein expression of human CCR8 in hCCR8 mice was evaluated by flow cytometer in a colon cancer cell line MC38 tumor bearing mouse model. The human CCR8 protein were successfully detected in tumor-infiltrating Tregs in B-hCCR8 mice bearing MC38 tumor, but not in Treg cells from spleen. An anti-tumor efficacy study showed significant tumor growth inhibition of hCCR8 antibodies in B-hCCR8 mice bearing MC38 tumors, suggesting that the B-hCCR8 mouse model is an effective tool for in vivo efficacy evaluation of therapeutic hCCR8 antibodies to support anti-human CCR8 antibody clinical development. Citation Format: Linlin Wang, Chengzhang Shang, Jing Zhang, Yichao Chen, Leila Kokabee, Qingcong Lin. Humanized CCR8 mouse model provides a translational tool for anti-human CCR8 antibody drug development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2954.

Abstract 2806: Development of an iRFP713-based orthotopic patient derived brain cancer model to study tumor development in vivo

Abstract While the use of bioluminescent proteins for molecular imaging is a powerful technology to support our knowledge of complex processes, with the advent of near infrared-labeling capabilities optical imaging can be pursuit with deeper tissue penetration, a better signal to background ratio and a quicker image acquisition without the need to inject substrates in preclinical oncology mouse models. This is specifically important in orthoptic brain tumors, when the substrate concentration in the tumor tissue might be influenced by the blood-brain barrier. In our recent study, we validated the feasibility of stable or transient transfection of human brain tumor cell lines and patient derived xenografts to determine tumor load in an intracranial setting. As a proof-of principle, we stably transfected the human glioblastoma cell line U87MG with an iRFP713 construct and followed tumor growth of intracranially implanted NSG mice. As a follow-up, five PDX of pediatric brain tumors (two Ependymoma, two Medulloblastoma, one high grade Glioblastoma) were transiently transfected with the same construct 24h before intracranial implantation. Tumor load was determined twice a week with the Pearl trilogy system (LiCor, Germany) and animals were examined for neurological symptoms every day. When the overall condition of the mice got deteriorated, animals were taken down and brains fixed in formalin. The tumor load and localization was confirmed by H&E and human-specific IHC for LamininB. The comparison between non-transfected and transfected lines of one specific tumor model, revealed that the tumor growth was very similar in both settings. The tumor take rate was as well not affected. In the subsequent analyses we could show that the tumor load linearly correlated with the imaging signal. Moreover, the iRFP713 signal was stable post-resection of the tumor. Thus, it was possible to correlate the tumor load quantification via iRFP713-Protein expression and LamininB-IHC within one slide. The transient transfection was successful for the five tested models. When termination criteria were reached, over 90% of the tumor tissue were expressing the iRFP713 protein. The more general applicability for larger cohorts of mice (> 20) and drug testing experiments will be evaluated soon. We believe the superior optical properties of iRFP713 will be a valuable asset to overcome some of the complications inherent to imaging live animals and a powerful tool for preclinical drug development in clinical relevant mouse models of brain cancer. Citation Format: Kanstantsin Lashuk, Jacqueline Bersano, Dorothee Lenhard, Eva Oswald, Kerstin Klingner, Julia Schüler. Development of an iRFP713-based orthotopic patient derived brain cancer model to study tumor development in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2806.

Spreadsheet-Based Minimal Physiological Models for the Prediction of Clearance of Therapeutic Proteins in Pediatric Patients.

There is a growing interest in the use of physiologically based pharmacokinetic (PBPK) models as clinical pharmacology drug development tools. In PBPK modeling, not every organ or physiological parameter is required, leading to the development of a minimal PBPK (mPBPK) model, which is simple and efficient. The objective of this study was to streamline mPBPK modeling approaches and enable straightforward prediction of clearance of protein-based products in children. Four mPBPK models for scaling clearance from adult to children were developed and evaluated on Excel spreadsheets using (1) liver and kidneys; (2) liver, kidneys, and skin; (3) liver, kidneys, skin, and lymph; and (4) interstitial, lymph, and plasma volume. There were 35 therapeutic proteins with a total of 113 observations across different age groups (premature neonates to adolescents). For monoclonal and polyclonal antibodies, more than 90% of observations were within a 0.5- to 2-fold prediction error for all 4 methods. For nonantibodies, 79% to 100% of observations were within the 0.5- to 2-fold prediction error for the 4 different methods. Methods 1 and 4 provided the best results, >90% of the total observations were within the 0.5- to 2-fold prediction error for all 3 classes of protein-based products across a wide age range. The precision of clearance prediction was comparatively lower in children ≤2 years of age vs older children (>2 years of age) with methods 1 and 4 predicting 80% to 100% and 75% to 90% of observations within the 0.5- to 2-fold prediction error, respectively. The results of the study indicated that mPBPK models can be developed on spreadsheets, with acceptable performance for prediction of clearance.

In Situ Vitrification of Lung Cancer Organoids on a Microwell Array.

Three-dimensional cultured patient-derived cancer organoids (PDOs) represent a powerful tool for anti-cancer drug development due to their similarity to the in vivo tumor tissues. However, the culture and manipulation of PDOs is more difficult than 2D cultured cell lines due to the presence of the culture matrix and the 3D feature of the organoids. In our other study, we established a method for lung cancer organoid (LCO)-based drug sensitivity tests on the superhydrophobic microwell array chip (SMAR-chip). Here, we describe a novel in situ cryopreservation technology on the SMAR-chip to preserve the viability of the organoids for future drug sensitivity tests. We compared two cryopreservation approaches (slow freezing and vitrification) and demonstrated that vitrification performed better at preserving the viability of LCOs. Next, we developed a simple procedure for in situ cryopreservation and thawing of the LCOs on the SMAR-chip. We proved that the on-chip cryopreserved organoids can be recovered successfully and, more importantly, showing similar responses to anti-cancer drugs as the unfrozen controls. This in situ vitrification technology eliminated the harvesting and centrifugation steps in conventional cryopreservation, making the whole freeze–thaw process easier to perform and the preserved LCOs ready to be used for the subsequent drug sensitivity test.

P103 Minimal Clinically Important Difference (MCID) for the Ulcerative Colitis Patient-Reported Outcomes Signs and Symptoms (UC-PRO/SS) Tool

Abstract Background The UC-PRO/SS tool developed by the IBD PRO Consortium is undergoing FDA Drug Development Tool qualification (COA DDT# 000040). Derivation of minimal clinically important difference (MCID) thresholds for improvement in bowel and functional signs and symptoms domain scores are presented here. Methods MCID estimates for bowel and functional domains were derived using anchor- and distribution-based approaches applied to data from three studies of Etrolizumab. Initial MCIDs were developed using Mayo Clinic Score (MCS) and Inflammatory Bowel Disease Questionnaire (IBDQ) response thresholds as anchors; Cronbach’s alpha SEM and Cohen’s moderate effect size statistics were calculated. MCIDs were then cross-validated internally and externally, i.e. within and across target populations, using clinical (modified and partial MCS) and patient-centered (IBDQ “general wellness” item 10 and EQ5D VAS) measures, to support generalizability. CDF plots with pooled data provide further empirical support. Results Study populations had mean ages of 39.2–40.5 years; were 54.5–58% male; 77.5–93.9% white; and had mean disease duration of 8.75–8.98 years. Six points was selected as the bowel domain threshold as change of this magnitude aligns with the anchor settings (5.89, 6.93, and 7.15 for IBDQ and 5.63, 6.12, and 7.63 for MCS) and exceeds measurement error as shown by distributional methods (Cronbach’s alpha SEM 2.071, 2.160, and 2.167, Cohen’s moderate effect size range 2.086, 2.135, and 2.191). A two-point threshold was similarly selected for the functional domain based on anchor settings (1.77, 1.98, and 2.53 for IBDQ and 1.56, 1.68, and 2.01 for MCS) and distributional methods (Cronbach’s alpha SEM 1.336,1.140, and 1.417, Cohen’s moderate effect size range 1.204, 1.270, and 1.309). External, cross-validation showed numerically robust differences (no overlapping CI’s) between the group achieving the MCID versus not across clinical and PRO variables for both domains. Magnitudes of change on IBDQ item 10 and EQ5D VAS variables scores exceeded the ½ SD for interpreting moderate levels of PRO score change. For the bowel domain, separation of CDF curves between responder groups showed cumulative percentages of approximately 60% and 70% based on IBDQ and MCS anchors, respectively, at the thresholds indicating change of a six-point magnitude. For the functional domain, separation between CDF curves at the 2-point threshold occurred at points indicating cumulative proportions of response greater than 50% using both anchors. Conclusion MCIDs of 6 and 2 points for the bowel and functional domains of the UC-PRO/SS are robustly defined and cross-validated, allowing interpretation of clinical improvement in symptoms among moderate to severe adult UC patients.

Generation of 20 human induced pluripotent stem cell lines from patients with focal segmental glomerulosclerosis (FSGS)

Focal segmental glomerulosclerosis (FSGS) is a major cause of familial nephrotic syndrome. We generated 20 induced pluripotent stem cell lines from patients diagnosed with FSGS. The iPSC lines include 8 female and 12 male lines and cover a donor age range from 31 to 78. The lines were generated from peripheral blood mononuclear cells by integration-free reprogramming using Sendai virus vectors. Cell lines were fully characterized regarding their pluripotency and differentiation potential, and quality controlled for karyotypic integrity, identity and clearance of reprogramming vectors. The generated cell lines represent a valuable tool for disease modelling and drug development for FSGS.

Characterization and quantification of necrotic tissues and morphology in multicellular ovarian cancer tumor spheroids using optical coherence tomography.

The three-dimensional (3D) tumor spheroid model is a critical tool for high-throughput ovarian cancer research and anticancer drug development in vitro. However, the 3D structure prevents high-resolution imaging of the inner side of the spheroids. We aim to visualize and characterize 3D morphological and physiological information of the contact multicellular ovarian tumor spheroids growing over time. We intend to further evaluate the distinctive evolutions of the tumor spheroid and necrotic tissue volumes in different cell numbers and determine the most appropriate mathematical model for fitting the growth of tumor spheroids and necrotic tissues. A label-free and noninvasive swept-source optical coherence tomography (SS-OCT) imaging platform was applied to obtain two-dimensional (2D) and 3D morphologies of ovarian tumor spheroids over 18 days. Ovarian tumor spheroids of two different initial cell numbers (5,000- and 50,000- cells) were cultured and imaged (each day) over the time of growth in 18 days. Four mathematical models (Exponential-Linear, Gompertz, logistic, and Boltzmann) were employed to describe the growth kinetics of the tumor spheroids volume and necrotic tissues. Ovarian tumor spheroids have different growth curves with different initial cell numbers and their growths contain different stages with various growth rates over 18 days. The volumes of 50,000-cells spheroids and the corresponding necrotic tissues are larger than that of the 5,000-cells spheroids. The formation of necrotic tissue in 5,000-cells numbers is slower than that in the 50,000-cells ones. Moreover, the Boltzmann model exhibits the best fitting performance for the growth of tumor spheroids and necrotic tissues. Optical coherence tomography (OCT) can serve as a promising imaging modality to visualize and characterize morphological and physiological features of multicellular ovarian tumor spheroids. The Boltzmann model integrating with 3D OCT data of ovarian tumor spheroids provides great potential for high-throughput cancer research in vitro and aiding in drug development.

Discovery of Natural Products Targeting NQO1 via an Approach Combining Network-Based Inference and Identification of Privileged Substructures.

NAD(P)H:quinone oxidoreductase 1 (NQO1) has been shown to be a potential therapeutic target for various human diseases, such as cancer and neurodegenerative disorders. Recent advances in computational methods, especially network-based methods, have made it possible to identify novel compounds for a target with high efficiency and low cost. In this study, we designed a workflow combining network-based methods and identification of privileged substructures to discover new compounds targeting NQO1 from a natural product library. According to the prediction results, we purchased 56 compounds for experimental validation. Without the assistance of privileged substructures, 31 compounds (31/56 = 55.4%) showed IC50 < 100 μM, and 11 compounds (11/56 = 19.6%) showed IC50 < 10 μM. With the assistance of privileged substructures, the two success rates were increased to 61.8 and 26.5%, respectively. Seven natural products further showed inhibitory activity on NQO1 at the cellular level, which may serve as lead compounds for further development. Moreover, network analysis revealed that osthole may exert anticancer effects against multiple cancer types by inhibiting not only carbonic anhydrases IX and XII but also NQO1. Our workflow and computational methods can be easily applied in other targets and become useful tools in drug discovery and development.

Monoclonal antibody therapy efficacy can be boosted by combinations with other treatments: Predictions using an integrated Alzheimer's Disease Platform.

For many years, clinical research in Alzheimer’s disease (AD) has focused on attempts to identify the most explicit biomarker, namely amyloid beta. Unfortunately, the numerous therapies that have been developed have failed in clinical practice. AD arises as a consequence of multiple factors, and as such it requires a more mechanistic analytical approach than statistical modeling. Quantitative systems pharmacology modeling is a valuable tool for drug development. It utilizes in vitro data for the calibration of parameters, embeds them into physiologically based structures, and explores translation between animals and humans. Such an approach allows for a quantitative study of the dynamics of the interactions between multiple factors or variables. Here, we present an overview of the quantitative translational model in AD, which embraces current preclinical and clinical data. The previously published description of amyloid physiology has been updated and joined with a model for tau pathology and multiple intraneuronal processes responsible for cellular transport, metabolism, or proteostasis. In addition, several hypotheses regarding the best correlates of cognitive deterioration have been validated using clinical data. Here, the amyloid hypothesis was unable to predict the aducanumab clinical trial data, whereas simulations of cognitive impairment coupled with tau seeding or neuronal breakdown (expressed as caspase activity) matched the data. A satisfactory validation of the data from multiple preclinical and clinical studies was followed by an attempt to predict the results of combinatorial treatment with targeted immunotherapy and activation of autophagy using rapamycin. The combination is predicted to yield better efficacy than immunotherapy alone.

The Role of Patient-reported Outcomes and Medication Adherence Assessment in Patient-focused Drug Development for Solid Organ Transplantation.

The Role of Patient-reported Outcomes and Medication Adherence Assessment in Patient-focused Drug Development for Solid Organ Transplantation.

Clinical Pharmacology Regulatory Sciences in Drug Development and Precision Medicine: Current Status and Emerging Trends.

In the regulatory setting, clinical pharmacology focuses on the impact of intrinsic and extrinsic factors on inter-patient and intra-subject variability in drug exposure and response. This translational science contributes to the understanding of the benefit-risk profile in individual patients and the development of relevant therapeutic monitoring and management strategies. Clinical pharmacology also plays a major role in the development and qualification of drug development tools. This article presented some recent examples to illustrate the important roles of clinical pharmacology in drug development and evaluation. In addition, emerging trends in clinical pharmacology regulatory sciences were also discussed, including the Model-Informed Drug Development (MIDD) pilot program, the use of real-world data to generate real-world evidence, and leveraging advances in basic, biomedical, and clinical science into useful tools for drug development and evaluation. Continued advances in clinical pharmacology can be the basis of more rational and efficient drug development and improved access to new drug treatments that are tailored to the patient to achieve better efficacy and safety.

In vitro model for predicting the access and distribution of drugs in the brain using hCMEC/D3 cells

The BBB is a protective entity that prevents external substances from reaching the CNS but it also hinders the delivery of drugs into the brain when they are needed. The main objective of this work was to improve a previously proposed in vitro cell-based model by using a more physiological cell line (hCMEC/D3) to predict the main pharmacokinetic parameters that describe the access and distribution of drugs in the CNS: Kpuu,brain, fu,plasma, fu,brain and Vu,brain. The hCMEC/D3 permeability of seven drugs was studied in transwell systems under different conditions (standard, modified with albumin and modified with brain homogenate). From the permeability coefficients of those experiments, the parameters mentioned above were calculated and four linear IVIVCs were established. The best ones were those that relate the in vitro and in vivo Vu,brain and fu,brain (r2 = 0.961 and r2 = 0.940) which represent the binding rate of a substance to the brain tissue, evidencing the importance of using brain homogenate to mimic brain tissue when an in vitro brain permeability assay is done. This methodology could be a high-throughput screening tool in drug development to select the CNS promising drugs in three different in vitro BBB models (hCMEC/D3, MDCK and MDCK-MDR1).

Conditional distribution modeling as an alternative method for covariates simulation: Comparison with joint multivariate normal and bootstrap techniques.

Clinical trial simulation (CTS) is a valuable tool in drug development. To obtain realistic scenarios, the subjects included in the CTS must be representative of the target population. Common ways of generating virtual subjects are based upon bootstrap (BS) procedures or multivariate normal distributions (MVNDs). Here, we investigated the performance of an alternative method based on conditional distributions (CDs). Covariate data from a hypertension drug development program were used. The methods were evaluated based on the original data set (internal evaluation) and on their ability to reproduce an older, unobserved population (extrapolation). Similar results were obtained in the internal evaluation for summary statistics, yet BS was able to preserve the correlation structure of the empirical distribution, which was not adequately reproduced by MVND; CD was in between BS and MVND. BS does not allow to extrapolate to an unobserved population. When the data set used to inform the extrapolation was well approximated by an MVND, the results from CD and MVND were comparable. However, improved extrapolation performance was observed for CD when deviations from normality assumptions occurred. If CTS is used to simulate within the observed distribution, BS is the preferred method. When extrapolating to new populations, a parametric method like CD/MVND is needed. In case the empirical multivariate distribution is characterized by linearly related covariates and unimodal marginal distributions, MVND can be used because of the simpler statistical framework and well‐established use; however, if uncertainty about the MVND assumptions exists, CD will increase the confidence in the simulations compared to MVND.