Target-Mediated Drug Disposition-A Class Effect of Soluble Epoxide Hydrolase Inhibitors

Inhibition of Soluble Epoxide Hydrolase Reduces Inflammation and Myocardial Injury in Arrhythmogenic Cardiomyopathy

We analyzed the role of pro- and anti-inflammatory eicosanoids in the pathogenesis of arrhythmogenic cardiomyopathy (ACM). Lipidomics revealed reduced levels of anti-inflammatory oxylipins in plasma and increased levels of pro-inflammatory eicosanoids in hearts of Dsg2mut/mut mice, a preclinical model of ACM. Disease features were reversed in vitro in rat ventricular myocytes expressing mutant JUP by the anti-inflammatory epoxyeicosatrienoic acid 14-15-EET, whereas 14,15-EEZE, which antagonizes the 14,15-EET receptor, intensified nuclear accumulation of the desmosomal protein plakoglobin. Inhibition of soluble epoxide hydrolase (sEH), an enzyme that converts anti-inflammatory EETs into polar, less active diols, prevented progression of myocardial injury in Dsg2mut/mut mice and promoted recovery of contractile function. This was associated with reduced myocardial expression of genes involved in innate immune signaling and fewer injurious macrophages expressing CCR2. These results suggest that pro-inflammatory eicosanoids contribute to the pathogenesis of ACM. Inhibition of sEH may be an effective, mechanism-based therapy for ACM patients.

Exploring the Impact of Pharmacological Target-Mediated Low Plasma Exposure in Lead Compound Selection in Drug Discovery - A Modeling Approach

Small-molecule drug development faces the challenge of low success rate. In this paper, we propose one potential cause that may occur in the preclinical phase and has rarely been brought up before - the neglected target-mediated low plasma exposure, and the subsequent lead compound mis-selection due to conventional pharmacokinetic criteria requiring sufficient plasma exposure and desired half-life. To evaluate the concept of target-mediate low plasma exposure, we established a minimal physiologically-based pharmacokinetic (mPBPK) model to evaluate the concentration-time profiles of a group of virtual lead series analogs in plasma and in tissues with and without pharmacological target expression. Simulation results demonstrated that the candidate with the highest target binding has the lowest plasma exposure due to target-mediated tissue retention. The traditional PK criteria, such as the requirement of sufficient plasma exposure and desired half-life, may potentially result in lead compound mis-selection by discarding the appropriate and best candidate(s). The mPBPK model was partially validated using 4 tyrosine kinase inhibitors based on our in-house PK and tissue distribution data obtained in animals. The association rate constant (Kass) was estimated to be 49.8 h-1, 31.4 h-1, 8.58 h-1, and 1.91 h-1 for afatinib, dasatinib, gefitinib, and sorafenib, respectively. Among these four model drugs, a strong correlation was observed between their Kass values and AUChigh-perfused tissue /AUCplasma ratios, a metric of tissue retention. Our mPBPK modeling and simulation results indicated that the concept of target-mediated low plasma exposure should be kept in mind during the lead compound selection process.

Can Machine Learning Overcome the 95% Failure Rate and Reality that Only 30% of Approved Cancer Drugs Meaningfully Extend Patient Survival?

Despite implementing hundreds of strategies, cancer drug development suffers from a 95% failure rate over 30 years, with only 30% of approved cancer drugs extending patient survival beyond 2.5 months. Adding more criteria without eliminating nonessential ones is impractical and may fall into the "survivorship bias" trap. Machine learning (ML) models may enhance efficiency by saving time and cost. Yet, they may not improve success rate without identifying the root causes of failure. We propose a "STAR-guided ML system" (structure-tissue/cell selectivity-activity relationship) to enhance success rate and efficiency by addressing three overlooked interdependent factors: potency/specificity to the on/off-targets determining efficacy in tumors at clinical doses, on/off-target-driven tissue/cell selectivity influencing adverse effects in the normal organs at clinical doses, and optimal clinical doses balancing efficacy/safety as determined by potency/specificity and tissue/cell selectivity. STAR-guided ML models can directly predict clinical dose/efficacy/safety from five features to design/select the best drugs, enhancing success and efficiency of cancer drug development.

Characterizing the Nonlinear Pharmacokinetics and Pharmacodynamics of BI 187004, an 11β-Hydroxysteroid Dehydrogenase Type 1 Inhibitor, in Humans by a Target-Mediated Drug Disposition Model

BI 187004, a selective small-molecule inhibitor of 11β-hydroxysteroid dehydrogenase-1 (11β-HSD1), displayed complex nonlinear pharmacokinetics (PK) in humans. Following nine single oral doses, BI 187004 exhibited nonlinear PK at low doses and linear PK at higher doses. Notably, substantial hepatic 11β-HSD1 inhibition (50%) was detected in a very low-dose group, achieving a consistent 70% hepatic enzyme inhibition in subsequent ascending doses without any dose-dependent effects. The unusual PK and PD profiles of BI 187004 suggest the presence of pharmacological target-mediated drug disposition (TMDD), arising from the saturable binding of BI 187004 compound to its high-affinity and low-capacity target 11β-HSD1. The non-intuitive dose, exposure, and response relationship for BI 187004 pose a significant challenge in rational dose selection. This study aimed to construct a TMDD model to explain the complex nonlinear PK behavior and underscore the importance of recognizing TMDD in this small-molecule compound. Among the various models explored, the best model was a two-compartment TMDD model with three transit absorption components. The final model provides insights into 11β-HSD1 binding-related parameters for BI 187004, including the total amount of 11β-HSD1 in the liver (estimated to be 8000 nmol), the second order association rate constant (estimated to be 0.102 nM-1h-1), and the first-order dissociation rate constant (estimated to be 0.11 h-1). Our final population PK model successfully characterized the intricate nonlinear PK of BI 187004 across a wide dose range. This modeling work serves as a valuable reference for the rational selection of the dose regimens for BI 187004's future clinical trials.

Inhibition of Soluble Epoxide Hydrolase Reduces Inflammation and Myocardial Injury in Arrhythmogenic Cardiomyopathy

Previous studies have implicated persistent innate immune signaling in the pathogenesis of arrhythmogenic cardiomyopathy (ACM), a familial non-ischemic heart muscle disease characterized by life-threatening arrhythmias and progressive myocardial injury. Here, we provide new evidence implicating inflammatory lipid autocoids in ACM. We show that specialized pro-resolving lipid mediators are reduced in hearts of Dsg2mut/mut mice, a well characterized mouse model of ACM. We also found that ACM disease features can be reversed in rat ventricular myocytes expressing mutant JUP by the pro-resolving epoxy fatty acid (EpFA) 14,15-eicosatrienoic acid (14-15-EET), whereas 14,15-EE-5(Z)E which antagonizes actions of the putative 14,15-EET receptor, intensified nuclear accumulation of the desmosomal protein plakoglobin. Soluble epoxide hydrolase (sEH), an enzyme that rapidly converts pro-resolving EpFAs into polar, far less active or even pro-inflammatory diols, is highly expressed in cardiac myocytes in Dsg2mut/mut mice. Inhibition of sEH prevented progression of myocardial injury in Dsg2mut/mut mice and led to recovery of contractile function. This was associated with reduced myocardial expression of genes involved in the innate immune response and fewer pro-inflammatory macrophages expressing CCR2, which mediate myocardial injury in Dsg2mut/mut mice. These results suggest that pro-inflammatory eicosanoids contribute to the pathogenesis of ACM and, further, that inhibition of sEH may be an effective, mechanism-based therapy for ACM patients.

Genetic deletion or pharmacological inhibition of soluble epoxide hydrolase attenuated particulate matter 2.5 exposure mediated lung injury

Air pollution represented by particulate matter 2.5 (PM2.5) is closely related to diseases of the respiratory system. Although the understanding of its mechanism is limited, pulmonary inflammation is closely correlated with PM2.5-mediated lung injury. Soluble epoxide hydrolase (sEH) and epoxy fatty acids play a vital role in the inflammation. Herein, we attempted to use the metabolomics of oxidized lipids for analyzing the relationship of oxylipins with lung injury in a PM2.5-mediated mouse model, and found that the cytochrome P450 oxidases/sEH mediated metabolic pathway was involved in lung injury. Furthermore, the sEH overexpression was revealed in lung injury mice. Interestingly, sEH genetic deletion or the selective sEH inhibitor TPPU increased levels of epoxyeicosatrienoic acids (EETs) in lung injury mice, and inactivated pulmonary macrophages based on the MAPK/NF-κB pathway, resulting in protection against PM2.5-mediated lung injury. Additionally, a natural sEH inhibitor luteolin from Inula japonica displayed a pulmonary protective effect towards lung injury mediated by PM2.5 as well. Our results are consistent with the sEH message and protein being both a marker and mechanism for PM2.5-induced inflammation, which suggest its potential as a pharmaceutical target for treating diseases of the respiratory system.

Cytochrome P450 and Other Drug-Metabolizing Enzymes As Therapeutic Targets

Cytochrome P450 and other families of drug-metabolizing enzymes are commonly thought of and studied for their ability to metabolize xenobiotics and other foreign entities as they are eliminated from the body. Equally as important, however, is the homeostatic role that many of these enzymes play in maintaining the proper levels of endogenous signaling molecules such as lipids, steroids, and eicosanoids as well as their ability to modulate protein-protein interactions involved in downstream signaling cascades. Throughout the years, many of these endogenous ligands or protein partners of drug-metabolizing enzymes have been associated with a wide range of disease states from cancer to various cardiovascular, neurologic, or inflammatory diseases, prompting an interest in whether modulation of drug-metabolizing enzyme activity could have a subsequent pharmacological impact or lessening of disease severity. Beyond direct regulation of endogenous pathways, drug-metabolizing enzymes have also been proactively targeted for their ability to activate prodrugs with subsequent pharmacological activity or enhance the efficacy of a coadministered drug by inhibiting the metabolism of that drug through a rationally designed drug-drug interaction (i.e., ritonavir and human immunodeficiency virus antiretroviral therapy). The focus of this minireview will be to highlight research aimed at characterizing cytochrome P450 and other drug-metabolizing enzymes as therapeutic targets. Examples of successfully marketed drugs as well as early research efforts will be discussed. Finally, emerging areas of research utilizing typical drug-metabolizing enzymes to impact clinical outcomes will be discussed. SIGNIFICANCE STATEMENT: Although generally thought of for their drug-metabolizing capabilities, enzymes such as the cytochromes P450, glutathione S-transferases, soluble epoxide hydrolases, and others play a significant role in regulating key endogenous pathways, making them potential drug targets. This minireview will cover various efforts over the years to modulate drug-metabolizing enzyme activity toward pharmacological outcomes.

A Pharmacometrics Model to Characterize a New Type of Target-Mediated Drug Disposition (TMDD) - Nonlinear Pharmacokinetics of Small-Molecule PF-07059013 Mediated By Its High-capacity Pharmacological Target Hemoglobin With Positive Cooperative Binding

In general, small-molecule target-mediated drug disposition (TMDD) is caused by the interaction of a drug with its high-affinity, low-capacity pharmacological target. In the current work, we developed a pharmacometrics model to characterize a new type of TMDD, where the nonlinear pharmacokinetics (PK) is mediated by a high-capacity pharmacological target with cooperative binding instead of target saturation. The model drug we used was PF-07059013, a noncovalent hemoglobin modulator that demonstrated promising preclinical efficacy to treat sickle cell disease (SCD), and showed complex nonlinear PK in mice with the fraction of unbound drug in blood (fu_b) decreased with an increase in PF-07059013 concentrations/doses due to the positive cooperative binding of PF-07059013 to hemoglobin. Among the various models we evaluated, the best one is a semi-mechanistic model where only drug molecules not bound to hemoglobin were allowed for elimination, with the nonlinear pharmacokinetics being captured by incorporating cooperative binding for drug molecules bound to hemoglobin. Our final model provided valuable insight on target binding-related parameters, such as the Hill coefficient γ (estimated to be 1.6), binding constant K_H (estimated to be 1450 µM), and the amount of total hemoglobin R_tot (estimated to be 2.13 µmol). As the dose selection of a compound with positive cooperative binding is tricky and challenging due to the nonproportional and steep response, our model may be valuable in facilitating the rational dose regimen selection for future preclinical animal and clinical trials for PF-07059013 and other compounds whose nonlinear pharmacokinetics are caused by similar mechanisms.

Macrophage Inactivation by Small Molecule Wedelolactone via Targeting sEH for the Treatment of LPS-Induced Acute Lung Injury

Soluble epoxide hydrolase (sEH) plays a critical role in inflammation by modulating levels of epoxyeicosatrienoic acids (EETs) and other epoxy fatty acids (EpFAs). Here, we investigate the possible role of sEH in lipopolysaccharide (LPS)-mediated macrophage activation and acute lung injury (ALI). In this study, we found that a small molecule, wedelolactone (WED), targeted sEH and led to macrophage inactivation. Through the molecular interaction with amino acids Phe362 and Gln384, WED suppressed sEH activity to enhance levels of EETs, thus attenuating inflammation and oxidative stress by regulating glycogen synthase kinase 3beta (GSK3β)-mediated nuclear factor-kappa B (NF-κB) and nuclear factor E2-related factor 2 (Nrf2) pathways in vitro. In an LPS-stimulated ALI animal model, pharmacological sEH inhibition by WED or sEH knockout (KO) alleviated pulmonary damage, such as the increase in the alveolar wall thickness and collapse. Additionally, WED or sEH genetic KO both suppressed macrophage activation and attenuated inflammation and oxidative stress in vivo. These findings provided the broader prospects for ALI treatment by targeting sEH to alleviate inflammation and oxidative stress and suggested WED as a natural lead candidate for the development of novel synthetic sEH inhibitors.

Direct targeting of sEH with alisol B alleviated the apoptosis, inflammation, and oxidative stress in cisplatin-induced acute kidney injury

Acute kidney injury (AKI) is a pathological condition characterized by a rapid decrease in glomerular filtration rate and nitrogenous waste accumulation during hemodynamic regulation. Alisol B, from Alisma orientale, displays anti-tumor, anti-complement, and anti-inflammatory effects. However, its effect and action mechanism on AKI is still unclear. Herein, alisol B significantly attenuated cisplatin (Cis)-induced renal tubular apoptosis through decreasing expressions levels of cleaved-caspase 3 and cleaved-PARP and the ratio of Bax/Bcl-2 depended on the p53 pathway. Alisol B also alleviated Cis-induced inflammatory response (e.g. the increase of ICAM-1, MCP-1, COX-2, iNOS, IL-6, and TNF-α) and oxidative stress (e.g. the decrease of SOD and GSH, the decrease of HO-1, GCLC, GCLM, and NQO-1) through the NF-κB and Nrf2 pathways. In a target fishing experiment, alisol B bound to soluble epoxide hydrolase (sEH) as a direct cellular target through the hydrogen bond with Gln384, which was further supported by inhibition kinetics and surface plasmon resonance (equilibrium dissociation constant, K _D = 1.32 μM). Notably, alisol B enhanced levels of epoxyeicosatrienoic acids and decreased levels of dihydroxyeicosatrienoic acids, indicating that alisol B reduced the sEH activity in vivo. In addition, sEH genetic deletion alleviated Cis-induced AKI and abolished the protective effect of alisol B in Cis-induced AKI as well. These findings indicated that alisol B targeted sEH to alleviate Cis-induced AKI via GSK3β-mediated p53, NF-κB, and Nrf2 signaling pathways and could be used as a potential therapeutic agent in the treatment of AKI.

Importance of Target-Mediated Drug Disposition (TMDD) of Small-Molecule Compounds and Its Impact on Drug Development-Example of the Class Effect of HSD-1 Inhibitors

With more potent drug candidates being developed, the incidence of target-mediated drug disposition (TMDD) in small-molecule compounds has significantly increased in the past decade. Moreover, TMDD appears to apply to some small-molecule compound classes. The main purpose of the current review is to increase the awareness of TMDD in a series of small-molecule inhibitors of 11β-hydroxysteroid dehydrogenase type 1 (HSD-1) using ABT-384, SPI-62, MK-0916, BMS-823778, and BI-187004 as case examples. Although developed independently by different pharmaceutical companies, these HSD-1 inhibitors demonstrated strikingly similar nonlinear pharmacokinetic behaviors when wide dose ranges were evaluated in first-in-human (FIH) single ascending dose (SAD) and multiple ascending dose (MAD) studies. Recognizing TMDD in small-molecule compounds is important, as the information can be leveraged to select the appropriate dose regimen, improve clinical trial design, as well as predict pharmacological target occupancy. In this review, we summarize the general pharmacokinetic features that facilitate the recognition of small-molecule TMDD, provide case examples of specific HSD-1 inhibitors, highlight the importance of recognizing TMDD of small-molecule compounds during clinical development, and comment on the importance of utilizing pharmacometric modeling to facilitate the quantitative understanding of small-molecule compounds exhibiting TMDD.

Species Differences in Metabolism of Soluble Epoxide Hydrolase Inhibitor, EC1728, Highlight the Importance of Clinically Relevant Screening Mechanisms in Drug Development

There are few novel therapeutic options available for companion animals, and medications rely heavily on repurposed drugs developed for other species. Considering the diversity of species and breeds in companion animal medicine, comprehensive PK exposures in the companion animal patient is often lacking. The purpose of this paper was to assess the pharmacokinetics after oral and intravenous dosing in domesticated animal species (dogs, cats, and horses) of a novel soluble epoxide hydrolase inhibitor, EC1728, being developed for the treatment of pain in animals. Results: Intravenous and oral administration revealed that bioavailability was similar for dogs, and horses (42 and 50% F) but lower in mice and cats (34 and 8%, respectively). Additionally, clearance was similar between cats and mice, but >2× faster in cats vs. dogs and horses. Efficacy with EC1728 has been demonstrated in mice, dogs, and horses, and despite the rapid clearance of EC1728 in cats, analgesic efficacy was demonstrated in an acute pain model after intravenous but not oral dosing. Conclusion: These results demonstrate that exposures across species can vary, and investigation of therapeutic exposures in target species is needed to provide adequate care that addresses efficacy and avoids toxicity.