Busulfan-induced hepatic sinusoidal endothelial cell injury: Modulatory role of pirfenidone for therapeutic purposes.

Transplantation conditioning using Busulfan has been known to cause hepatotoxicity, which has great individual differences. Some have mild symptoms like the increase of hepatic drug-metabolizing enzyme, while others may have very serious ones, like hepatic sinusoidal obstruction syndrome. However, simply controlling the exposure of Busulfan may not effectively prevent or reduce the occurrence of hepatic sinusoidal obstruction syndrome. The occurrence of hepatic sinusoid obstruction syndrome is closely related to hepatic sinusoidal endothelial cells (HSECs). The objective of this study is to investigate the potential protective effect of Pirfenidone against Busulfan-induced damage to hepatic sinusoidal endothelial cells and to preliminarily explore the mechanisms underlying this protective effect. Our results indicate that Pirfenidone has a great protective effect on the injury induced by Busulfan. In addition, Busulfan increased the relative mRNA expression of transforming growth factor-ß1 (TGF-ß1), collagen and tissue inhibitor of metalloproteinase-1 in HSECs. After pretreatment with Pirfenidone, the expression level of TGF-ß1 was down-regulated. Mechanically, Pirfenidone primarily improves liver fibrosis by inhibiting collagen formation and hepatic stellate cell activation, thereby providing a protective effect on HSECs damaged by Busulfan. Therefore, Pirfenidone may reduce the hepatotoxicity caused by transplantation conditioning regimens based on Busulfan.

Pharmacokinetics, Mass Balance and Metabolism of [14C]HSK21542, a Novel Kappa Opioid Receptor Agonist, in Humans.

BACKGROUND AND OBJECTIVE: HSK21542, a synthetic short-chain polypeptide, is a selective peripheral kappa opioid receptor (KOR) agonist. In this single-centre, non-randomized, open-label study, the pharmacokinetics, mass balance, metabolism and excretion of HSK21542 were investigated. METHODS: A single intravenous dose of 2 µg/0.212 µCi/kg [14C]HSK21542 was administered to six healthy male subjects. Samples of blood, urine and faeces were collected for quantitative determination of total radioactivity and unchanged HSK21542, and identification of metabolites. RESULTS: The mean total recovery was 81.89% of the radiolabelled dose over 240 h post-dose, with 35.60% and 46.30% excreted in faeces and urine, respectively. The mean maximum concentration (Cmax), the half-life (t1/2) and the area under the concentration-time curve (AUC0-t) of total radioactivity (TRA) in plasma were 20.4 ±4.16 ng Eq./g, 1.93 ± 0.322 h and 21.8 ± 2.93 h·ng Eq./g, respectively, while the Cmax, t1/2 and the AUC0-t of unchanged HSK21542 were 18.3 ± 3.36 ng/mL, 1.66 ± 0.185 h and 18.4 ± 2.24 h·ng/mL, respectively. The blood-to-plasma ratios of TRA at several times ranged from 0.46 to 0.54. [14C]HSK21542 was detected as the main circulating substance in plasma, accounting for 92.17% of the AUC of TRA. The unchanged parent compound was the only major radioactive chemical in urine (100.00% of TRA) and faeces (93.53% of TRA). Metabolites were very minor components. CONCLUSIONS: HSK21542 was barely metabolized in vivo and mainly excreted with unchanged HSK21542 as its main circulating component in plasma. It was speculated that renal excretion was the principal excretion pathway, and faecal excretion was the secondary pathway. CLINICAL TRIAL REGISTRATION NUMBER: NCT05835934.

Effect of More Intensive LDL-C-Lowering Therapy on Long-term Cardiovascular Outcomes in Early-Phase Acute Coronary Syndrome: A Systematic Review and Meta-analysis.

PURPOSE: The effect of more intensive LDL-C-lowering therapy (ILLT) on long-term cardiovascular outcomes during the early phase of acute coronary syndromes (ACSs) remains uncertain. We aimed to explore the influence of more intensive LDL-C-lowering therapyduring the early disease phase on long-term cardiovascular events among patients with ACSs. METHODS: Randomized controlled trials that focused on the effect of more ILLT during early-phase ACSs on long-term major adverse cardiac events (MACEs) were searched in electronic databases (MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases) from database inception until November 23, 2019. The end points included the incidence of MACEs, myocardial infarction, stroke, revascularization, heart failure, and death events. Study risk of bias was assessed using the Cochrane Collaboration tools. Fixed- or random-effects models and meta-regression were performed to evaluate the association between baseline/proportional reduction of LDL-C levels during early-phase disease and the risk of end points using risk ratios with 95% CIs. FINDINGS: A total of 53,199 participants were involved from 19 studies. The risk of MACEs decreased by 17% (95% CI, 0.76-0.90; P = 0.0012) for more intensive versus control therapy but varied by baseline and proportional reduction of LDL-C levels during early disease phase. The risk reduction of MACEs for more intensive versus control therapy among different subgroups was 26% (95% CI, 0.57-0.95; P = 0.06) with a baseline level >130 mg/dL, 23% (95% CI, 0.63-0.94; P = 0.02) with a baseline level of 100 to 130 mg/dL, and 10% (95% CI, 0.83-0.99; P = 0.07) with a baseline level <100 mg/dL. A significant difference of risk reduction for MACEs existed between patients treated with statin plus ezetimibe versus statin alone in the subgroup with a baseline level >130 mg/dL and proportional reduction >50%. Patients treated with more intensive therapy benefited from reduced risk of myocardial infarction, stroke, revascularization, and heart failure compared with control therapy. IMPLICATIONS: More ILLT during early disease phase could significantly reduce the risk of long-term cardiovascular outcome in patients with ACSs. This benefit was most pronounced in patients with higher baseline and larger reduction of LDL-C levels in MACEs.

Optimization of Busulfan Dosing Regimen in Pediatric Patients Using a Population Pharmacokinetic Model Incorporating GST Mutations.

PURPOSE: The aim of this study was to develop a novel busulfan dosing regimen, based on a population pharmacokinetic (PPK) model in Chinese children, and to achieve better area under the concentration-time curve (AUC) targeting. PATIENTS AND METHODS: We collected busulfan concentration-time samples from 69 children who received intravenous busulfan prior to allogeneic hematopoietic stem cell transplantation (allo-HSCT). A population pharmacokinetic model for busulfan was developed by nonlinear mixed effect modelling and was validated by an external dataset (n=14). A novel busulfan dosing regimen was developed through simulated patients, and has been verified on real patients. Limited sampling strategy (LSS) was established by Bayesian forecasting. Mean absolute prediction error (MAPE) and relative root mean Squared error (rRMSE) were calculated to evaluate predictive accuracy. RESULTS: A one-compartment model with first-order elimination best described the data. GSTA1 genotypes, body surface area (BSA) and aspartate aminotransferase (AST) were found to be significant covariates of Bu clearance, and BSA had significant impact of the volume of distribution. Moreover, two equations were obtained for recommended dose regimens: dose (mg)=34.14×BSA (m2)+3.75 (for GSTA1 *A/*A), Dose (mg)=30.99×BSA (m2)+3.21 (for GSTA1 *A/*B). We also presented a piecewise dosage based on BSA categories for each GSTA1 mutation. A two-point LSS, two hours and four hours after dosing, behaved well with acceptable prediction precision (rRMSE=1.026%, MAPE=6.55%). CONCLUSION: We recommend a GSTA1-BSA and BSA-based dosing (Q6 h) based on a PPK model for personalizing busulfan therapy in pediatric population. Additionally, an optimal LSS (C2h and C4h) provides convenience for therapeutic drug monitoring (TDM) in the future.

Preparation, Characterization, Pharmacokinetic, and Therapeutic Potential of Novel 6-Mercaptopurine-Loaded Oral Nanomedicines for Acute Lymphoblastic Leukemia.

BACKGROUND: Acute lymphoblastic leukemia (ALL) is the most common hematologic malignancy in children. It requires a long and rigorous course of chemotherapy treatments. 6-Mercaptopurine (6-MP) is one of the primary drugs used in chemotherapy. Unfortunately, its efficacy has been limited due to its insolubility, poor bioavailability and serious adverse effects. To overcome these drawbacks, we constructed 6-mercaptopurine (6-MP)-loaded nanomedicines (6-MPNs) with biodegradable poly(lactide-co-glycolide) (PLGA) to enhance the anticancer efficacy of 6-MP. METHODS: We prepared the 6-MPNs using a double-emulsion solvent evaporation method, characterizing them for the physicochemical properties. We then investigated the plasma, intestinal region and other organs in Sprague Dawley (SD) rats for pharmacokinetics. Additionally, we evaluated its anticancer efficacy in vitro on the human T leukemia cell line Jurkat and in vivo on the ALL model mice. RESULTS: The 6-MPNs were spherical in shape with uniform particle size and high encapsulation efficiency. The in vitro release profile showed that 6-MPNs exhibited a burst release that a sustained release phase then followed. The apoptosis assay demonstrated that 6-MPNs could improve the in vitro cytotoxicity in Jurkat cells. Pharmacokinetics profiles revealed that 6-MPNs had improved oral bioavailability. Tissue distribution experiments indicated that 6-MPNs increased the duodenum absorption of 6-MP, at the same time having a low accumulation of the toxic metabolites of 6-MP. The in vivo pharmacodynamics study revealed that 6-MPNs could prolong the survival time of the ALL model mice. The prepared 6-MPNs, therefore, have superior properties in terms of anticancer efficacy against ALL with reduced systemic toxicity. CONCLUSION: Our nanomedicines provide a promising delivery strategy for 6-MP; they offer a simple preparation method and high significance for clinical translation.

Systemic Evaluation on the Pharmacokinetics of Platinum-Based Anticancer Drugs From Animal to Cell Level: Based on Total Platinum and Intact Drugs.

Cisplatin, carboplatin, and oxaliplatin are the common platinum-based anticancer drugs widely used in the chemotherapeutic treatment of solid tumors in clinic. However, the comprehensive pharmacokinetics of platinum-based anticancer drugs has not been fully understood yet. This leads to many limitations for the further studies on their pharmacology and toxicology. In this study, we conduct a systemic evaluation on the pharmacokinetics of three platinum analogues at animal and cell levels, with quantification of both total platinum and intact drugs. A detailed animal study to address and compare the different pharmacokinetic behaviors of three platinum analogues has been conducted in three biological matrices: blood, plasma, and ultrafiltrate plasma. Carboplatin showed an obviously different pharmacokinetic characteristic from cisplatin and oxaliplatin. On the one hand, carboplatin has the highest proportion of Pt distribution in ultrafiltrate plasma. On the other hand, carboplatin has the highest intact drug exposure and longest intact drug elimination time in blood, plasma, and ultrafiltrate plasma, which may explain its high hematotoxicity. Additionally, the cellular and subcellular pharmacokinetics of oxaliplatin in two colon cancer HCT-116/LOVO cell lines has been elucidated for the first time. The biotransformation of intact oxaliplatin in cells was rapid with a fast elimination, however, the generated platinum-containing metabolites still exist within cells. The distribution of total platinum in the cytosol is higher than in the mitochondria, followed by the nucleus. Enrichment of platinum in mitochondria may affect the respiratory chain or energy metabolism, and further lead to cell apoptosis, which may indicate mitochondria as another potential target for efficacy and toxicity of oxaliplatin.