Polymorphisms in genes related to drug-metabolising enzymes may affect tacrolimus exposure. This study aimed to assess the influence of , , and polymorphisms on tacrolimus pharmacokinetics and outcomes in allogeneic haematopoietic stem cell transplantation (HSCT).Forty-six adult patients receiving oral tacrolimus at an initial dose of 0.03 mg/kg/day for acute graft versus host disease (GVHD) prophylaxis after allogeneic HSCT were enrolled in this retrospective study. Genetic polymorphisms were detected in relation to concentration/dose (C/D) ratios of tacrolimus and the incidence of acute GVHD and acute kidney injury (AKI).The genotype and co-administration of voriconazole were significantly associated with increased C/D ratios of tacrolimus ( < 0.05). 8055CC presents a significantly higher tacrolimus C/D ratio compared with carriers of 8055CT and 8055TT genotypes in allogeneic HSCT recipients with the allele ( = 0.033). Younger age and recipients with the allele were significantly associated with higher incidence of II-IV acute GVHD post-transplantation., 8055C > T, and concomitant use of voriconazole are important determinants affecting tacrolimus pharmacokinetics. Moreover, allele and younger age are independent risk factors for II-IV acute GVHD in HSCT recipients.

A four-compartment model is presented that simulates inorganic mercury [Hg(II)] pharmacokinetics in blood, tissue, and excreta over a 70-day period. Simulations are validated against data collected from five human subjects, and previously analyzed.In the model, two compartments simulate Hg(II) in blood: one for mobile-Hg(II) and the other for immobile-Hg(II). Two corresponding compartments simulate Hg(II) in tissue. Mobile-Hg(II) represents Hg(II) available for transport across cell membranes. Immobile-Hg(II) represents Hg(II) that is not easily transported.Following dosing, blood total-Hg(II) droped rapidly in all subjects. Blood mobile-Hg(II) also droped rapidly with a concomitant rise in blood immobile-Hg(II). For four subjects, immobile-Hg(II) became the dominant Hg(II) species in blood by day 4. For subject five, mobile-Hg(II) remained dominant in blood for the study duration.Tissue mobile-Hg(II) declined rapidly for four of the subjects, with a simultaneous rapid rise in tissue immobile-Hg(II). In subject 5, tissue mobile-Hg(II) declined linearly, and immobile-Hg(II) accumulated slowly in tissue. For all subjects, tissue mobile-Hg(II) is the primary source of fecal Hg(II). The major source for Hg(II) excreted into the urine is immobile-Hg(II) from tissue.

Idiopathic Pulmonary Fibrosis (IPF) is a chronic respiratory disorder for which pirfenidone is the recommended first-line anti-fibrotic treatment. While pirfenidone has demonstrated efficacy in slowing the progression of IPF, its use is associated with several challenges and unresolved issues that impact patient outcomes. Pirfenidone administration can result in gastrointestinal side effects, photosensitivity reactions, and significant drug interactions, particularly in patients with hepatic impairment. For those who experience intolerable side effects, dose reductions or temporary discontinuations are frequently employed. However, there is limited data on the efficacy of reduced doses, creating uncertainty about the balance between tolerability and therapeutic benefit.The aim of this study is to evaluate the currently proposed dosage adjustments and to develop new dosage regimens tailored to the needs of patients. Simulations were conducted to explore pirfenidone pharmacokinetics under various challenging conditions, including dose titration, withdrawal, retitration, moderate and severe hepatic impairment, co-administration of moderate (e.g. omeprazole) and strong (e.g. smoking) inducers of the CYP1A2 enzyme, gastrointestinal adverse events, and photosensitivity reactions.Simulations led to specific recommendations for physicians regarding dosage regimens in each condition. The recommended dosage adjustments are designed to maintain concentrations within acceptable levels, ensuring both safe and effective treatment.

Dolutegravir (DTG) is a key drug used to treat human immunodeficiency virus type-1 (HIV-1) infections. Adverse events (AEs) of DTG treatment, including headache, anxiety, depression, insomnia, and abnormal dreams, are influenced by sex, body weight, age, and serum bilirubin levels. DTG is mainly metabolised by members of the uridine diphosphate glucuronosyltransferase 1A subfamilies (UGT1As), especially UGT1A1.Some studies suggest a relationship between variants and AEs. The aim of this study was to identify UGT1A isoforms that exhibit DTG glucuronidation activity and determine the relationship between variants and DTG glucuronidation .UGT1A1, UGT1A3, UGT1A9, and UGT1A10 exhibited DTG glucuronidation activity, of which UGT1A1 was the most active. Furthermore, variants of these isoforms showed decreased DTG glucuronidation activity. The different variants of s, such as UGT1A1.6, UGT1A1.7, UGT1A1.35, UGT1A1.63, UGT1A3.5, UGT1A9.2, UGT1A10M59I, and UGT1A10T202I, showed reduced glucuronidation activity towards DTG in comparison with the wild-type s.This study elucidates the relationship between variants and the levels of glucuronidation associated with each variant.Checking for s may be helpful in predicting potential toxicities and adverse effects related to DTG treatment.

The aim of this study was to investigate the effects of renal function and polymorphism on the drug interaction between venetoclax and fluconazole in thirty acute myeloid leukaemia patients.The area under the plasma concentration-time curve (AUC) and trough concentration (C) of venetoclax and the fluconazole C were obtained from plasma samples on day 7 later after initiation of venetoclax 200 mg/day combined with fluconazole.The fluconazole C values in patients with moderate and severe renal impairment were significantly higher than those in patients with normal or mild impairment (median values 7037, 6234, and 4813 ng/mL, respectively,  = 0.026).In patients with genotype, the AUC and C of venetoclax were not associated with fluconazole C; however, in patients with a allele, a significant positive correlation was observed between venetoclax C and fluconazole C ( = 0.782,  = 0.004).The metabolism of venetoclax by CYP3A4 is inhibited even at low fluconazole C. In patients with a allele, CYP3A5 is inhibited when high fluconazole C is induced by renal impairment.The dose of fluconazole for prophylaxis may be 100 mg in patients with severe renal impairment receiving venetoclax therapy.

Drug products meeting the dissolution specifications is crucial in order to ensure consistent clinical performance. However, in certain cases, wider dissolution specifications may be required based on product behaviour. While the justification of such wider specifications may be challenging from a regulatory context, approaches such as physiological-based biopharmaceutics modeling (PBBM) can be utilised for this purpose.Product DRL is a fixed-dose combination product consisting of immediate release (IR) and extended-release (ER) portions. For the ER portion, the dissolution specifications consisted of four time points, and a proposal was made to relax the specification at the 2h time point (from 50-70% to 45-67%) to reduce the batch failures at the commercial scale.To support the wider specification, a PBBM was developed and extensively validated with literature & in-house studies. Virtual bioequivalence was performed using the pivotal clinical study data.Virtual dissolution profiles for proposed wider specifications were generated using three different approaches. The incorporation of lower and upper dissolution profiles into the model indicated the absence of impact on performance thereby justifying the specifications.Regulatory acceptance of proposed specifications with PBBM indicated the significance of using modeling approaches to reduce repeated testing thereby facilitating faster approvals.

1. Small molecule inhibitors of the PI3K pathway have been extensively investigated as potential anticancer agents. Among the effectors in this pathway, PI3Kα is the kinase most frequently associated with the development of tumours, through mutations and amplifications of the gene encoding the p110α catalytic subunit.2. Inavolisib (GDC-0077) is a potent and PI3Kα-selective inhibitor that also specifically triggers the degradation of the mutant p110α protein.3. We characterised inavolisib ADME properties in preclinical and studies, assessed its efficacy in the mutant KPL-4 breast cancer xenograft model, and predicted its pharmacokinetics and efficacious dose in humans.4. Inavolisib had a moderate permeability (1.9•10cm/s) in MDCK cells and was a P-gp and Bcrp1 substrate. It appeared metabolically stable in hepatocytes incubations from human and preclinical species. The systemic clearance was low in mouse, monkey and dog and high in rat. Oral bioavailability ranged from 57.5% to 100%. Inavolisib was efficacious in the KPL-4 sub-cutaneous xenograft model.5. The PK/PD model parameters estimated from the efficacy study, combined with PBPK model-predicted human PK profiles, projected that a dose of 3 mg could lead to clinical response. Inavolisib is currently being tested in phase 3 trials.

GFH009 is a potent and highly selective cyclin-dependent kinase 9 (CDK9) inhibitor currently under phase II clinical trials. In this study, we investigated the metabolism and disposition of GFH009 in Sprague-Dawley (SD) rats, as well as metabolism of CD-1 mouse, SD rat, beagle dog, cynomolgus monkey, and human.A radiolabelled study indicated that [C]GFH009 was quickly and widely distributed throughout the body, but presented low levels in brain, testis, and epididymis after a single intravenous dose of 6 mg (100 µCi)/kg to SD rats.GFH009 undergoes systemic metabolic changes, primarily through O-demethylation, oxidation to carboxylic acid and N-dealkylation, cleavage off the methoxyisopropyl moiety being a minor pathway. These metabolic pathways were found to be mainly consistent both and .In SD rats, GFH009 was rapidly and completely eliminated, with faeces serving as the major excretion pathway and urine serving as the minor one. Besides, the major clearance pathway for GFH009 was excretion and the minor one was metabolism.GFH009 exhibits favourable drug metabolism and pharmacokinetics (DMPK) properties, which provides valuable insights into the disposition of GFH009 and can be used to guide future clinical studies.

Benzophenone-3 (BP-3), commonly known as oxybenzone, is an organic compound that acts as a sunscreen, protecting the skin from UVA and UVB rays. Thus, the objective of this study was to investigate the effects of BP-3 on the liver and thyroid using morphological and biochemical approaches.Adult male zebrafish were randomly assigned to three groups, each with three repetitions ( = 10 per group) water control, solvent control (0.01% ethanol), and 1 μg/L of BP-3, using a static exposure system for 96 h. After the experiment, histopathological analyses of the liver and thyroid were performed, along with histochemical analyses (glycogen) and biochemical evaluations of the antioxidant enzymes superoxide dismutase (SOD) and Catalase (CAT).Exposure to BP-3 resulted in significant histopathological changes in the liver of , increasing the frequency of circulatory disturbances, progressive changes, inflammatory responses, and regressive changes. On the other hand, the thyroid gland did not show any morphological changes during exposure to BP-3, maintaining its typical structure with follicles. There was a significant increase in SOD activity, while CAT showed no changes after 96 h of exposure.The results obtained demonstrate that exposure to BP-3 causes significant morphophysiological changes in the liver of , highlighting not only the negative impacts on the health of these organisms but also the ecotoxicological potential of the substance and its consequences for aquatic biota in contaminated environments.

The study aimed to investigate the influence of interleukin (IL)-6 -174 G/C gene polymorphism on graft function (defined as estimated glomerular filtration rate, eGFR), as well as on the tacrolimus (Tac) pharmacokinetics during the five years after kidney transplantation.

Intramuscular (250 mg once weekly) or subcutaneous (275 mg once weekly) injections of 17-hydroxyprogesterone caproate (17-OHPC) has been utilised to prevent recurent spontaneous preterm birth in pregnant women with a short cervix or those with a prior preterm birth but its efficacy in these conditions has been questioned. It is unclear whether adequate concentrations of 17-OHPC reach the suspected target organs such as the cervix and uterus following either IM or SC administration.The objective of this study was to determine feasibility and safety of vaginal administration of 17-OHPC in adult female Sprague Dawley rats and female New Zealand rabbits.Gels containing 17-OHPC were administered intravaginally to rats and rabbits for 10 consecutive days. After the last dose, serial blood samples and terminal uterine and adipose tissue samples were collected. 17-OHPC concentrations were measured by LC-MS-MS.Tissue histology showed that intravaginal administration of 17-OHPC was safe. There was no renal or hepatic toxicity as measured by liver function and kidney function tests.Intravaginal administration of 17-OHPC resulted in low systemic plasma concentrations but substantially higher uterus and adipose tissue concentrations of 17-OHPC. Composition of the formulation affected the tissue distribution of 17-OHPC.Future studies warrant further evaluation of the effect and safety of daily intravaginal administration of 17-OHPC gel in pregnant animals.

The metabolism and disposition of zamicastat, a reversible dopamine β-hydroxylase (DβH) inhibitor, developed for treatment of Pulmonary Arterial Hypertension (PAH), were investigated in rats after oral and intravenous administration of [C]-zamicastat.Zamicastat was rapidly absorbed and widely distributed to peripheral tissues, with total radioactivity almost completely recovered 168 h post-dose. Its main route of excretion was via faeces, whilst urine and expired air had minor roles.Maximum plasma concentration of zamicastat-related radioactivity occurred in the first hours, remaining quantifiable up to 144 h. The unchanged zamicastat plasma peak was 2 h post-dose and declined to low levels over 24 h.Zamicastat metabolism occurs largely during the first 8 h with only one metabolite identified in the latest time-point (96 h), the isothiocyanic acid/thiocyanic acid (tautomeric forms). Zamicastat metabolic pathway involved multiple reactions comprising desulphurisation, oxidative desulphurisation, N-debenzylation followed by further oxidation or N-acetylation, and the unexpected multistep metabolic pathway leading to isothiocyanic acid/thiocyanic acid.

The drug-drug interaction (DDI) and CYP2C19 genetic variation can lead to a high blood concentration of voriconazole. CYP2C19 is a highly genetically polymorphic enzyme, and CYP2C19*2 is more frequent among Asians associated with reduced metabolism of drugs. Clinical study found that co-administration with omeprazole significantly increased voriconazole concentrations and there was an additive effect in CYP2C19*2 allele.CYP2C19 rs4244285 (681G>A) is the key polymorphism of CYP2C19*2 allele. This study aims to describe the effects of omeprazole on CYP2C19*1 and *2 (681G>A), and determine how CYP2C19 polymorphisms influence the DDI between omeprazole and voriconazole.Using the lentiviral expression system, we successfully generated HepG2-derived cell lines stably expressing CYP2C19*1 and *2 (681G>A). The results showed that the CYP2C19 mRNA level, protein level, and enzymatic activity were lower in HepG2-CYP2C19*2 (681G>A) than HepG2-CYP2C19*1 cells. Our study also showed that the inhibition rates of omeprazole on voriconazole had no significantly differences between CYP2C19*1 and *2 (681G>A). But the IC of omeprazole on CYP2C19*1 slightly lower than CYP2C19*2 (681G>A).Moreover, omeprazole inhibited CYP2C19 protein level in cells carrying CYP2C19*1 and CYP2C19*2 (681G>A). Our study demonstrated that omeprazole could inhibit voriconazole metabolism in both CYP2C19*1 and CYP2C19*2 (681G>A).

Isolated perfused rat liver (IPRL) experiments have been used to answer clearance-related questions, including evaluating the impact of pathological and physiological processes on hepatic clearance (). However, to date, IPRL data has not been evaluated for prediction accuracy.In addition to a detailed overview of available IPRL literature, we present an in-depth analysis of the performance of IPRL in prediction.While the entire dataset poorly predicted (GAFE = 3.2; 64% within 3-fold), IPRL conducted under optimal experimental conditions, such as in the presence of plasma proteins and with a perfusion rate within 2-fold of physiological liver blood flow and corrected for unbound fraction in the presence of red blood cells, can accurately predict rat (GAFE = 2.0; 78% within 3-fold). Careful consideration of experimental conditions is needed to allow proper data analysis.Further, isolated perfused liver experiments in other species, including human livers, may allow us to address the current - disconnects of hepatic metabolic clearance and improve our methodology for predictions.

Various pharmacokinetic changes have been reported in experimental hyperlipidemic (HL) animal models. To evaluate whether P-glycoprotein (P-gp) activity was affected in HL rats, we assessed the pharmacokinetics of dabigatran after oral administration of dabigatran etexilate (DABE); this is a dabigatran prodrug and a well-known P-gp substrate.HL and control rats exhibited similar area under the plasma concentration-time curve (AUC), total body clearance (CL), and steady state volume of distribution (V) values following intravenous administration of dabigatran (1 mg/kg). This suggested that the distribution and elimination of dabigatran were similar in control and HL rats.The hepatic and intestinal P-gp protein levels did not differ significantly between control and HL rats. The dabigatran AUC and extent of absolute oral bioavailability (F) values were similar in control and HL rats following oral administration of DABE (10 mg/kg as dabigatran). Therefore, there was no apparent change in intestinal P-gp activity in HL rats compared to control rats.This study revealed no significant change in P-gp expression or activity in the intestine or liver of HL rats, and similar pharmacokinetics of dabigatran. Hyperlipidaemia may not directly affect the oral absorption of P-gp substrate drugs.

LD14b is an amyloid-β (Aβ) 17β-hydroxysteroid dehydrogenase type 10 (Aβ-17β-HSD10) protein-protein interaction modulator that shows promising and activity to rescue Aβ-induced mitochondrial dysfunction, Aβ-induced toxicity, and Aβ-mediated inhibition of estradiol synthesis.The current study investigated human S9 fractions metabolic stability, apparent permeability, human and mouse plasma protein binding, pharmacokinetics, and tissue distribution in Balb/cJ mice. A fast (8-min), sensitive, reliable, and reproducible LC-MS/MS method was developed and validated over the dynamic range of 1-1000 ng/mL for the quantification of LD14b in different biological matrices (plasma, liver, kidney, brain, lungs, heart).LD14b was metabolically stable in human liver S9 fractions with 70% remaining after 90 minutes of incubation, showed intermediate apparent permeability of 3.55 × 10 cm/s and 6.16 × 10 cm/s for apical-to-basolateral (A-to-B) and basolateral-to-apical (B-to-A), respectively across the Caco-2 monolayer, and was medium/highly bound to human plasma proteins (84.1%), mouse plasma proteins (85.7%), and mouse brain homogenate (95.4%).LD14b showed an predicted % absorption of 52% in Balb/cJ mice and was well-distributed to the peripheral tissues (liver, kidney, lungs, and heart) including the brain.

Stable isotope labelling by amino acids in cell culture (SILAC) is an established technique used in quantitative mass spectrometry (MS)-based proteomics. SILAC is also used to generate stable isotope labelled (SIL) antibodies for internal standards (IS) used in LC-MS/MS bioassays to improve quantitative robustness.Total antibody (TAb) is measured to evaluate pharmacokinetics (PK) of antibody drug conjugate (ADC) candidates measured by either ligand binding (LBA) or LC-MS/MS. Herein, we describe an application of SILAC, where multiple SIL combinations of an antibody are used for cassette dosing and PK evaluation.Our preclinical studies demonstrate SILAC-labelled ADC therapeutics did not alter antibody PK. Furthermore, with cassette dosing SIL antibodies exhibited comparable exposure to discretely administered unlabelled test articles in rats.In addition, SIL antibodies were conjugated to cytotoxic payloads to create SIL ADCs and cassette dosed in a cynomolgus monkey PK study and SIL ADCs yielded comparable PK results to discrete dosed unlabelled ADCs.In conclusion, SIL antibodies used with a cassette dosing strategy increases PK screening throughput of ADC candidates in preclinical species. Additionally, cassette dosing strategy further facilitates the responsible use of laboratory animals to achieve the three-Rs (Replacement, Reduction, and Refinement).

Antibody-drug conjugates (ADCs) are a class of biopharmaceuticals that combine the specificity of monoclonal antibodies (mAbs) with the cytotoxicity of small molecule drugs. 15 ADCs have been approved by regulatory authorities up to now, mainly for indications in oncology, however, this review paper will only focus on the 13 ADCs that have been approved by either the FDA or EMA.ADME (Absorption, Distribution, Metabolism, and Excretion) studies are essential for the development of small molecule drugs to evaluate their disposition properties. These studies help to select drug candidates, determine the optimal dosing regimen and help to identify potential safety concerns for the drug of interest in human. Tissue distribution studies are also important as they facilitate the understanding of the efficacy and safety for parent drug and its metabolites in preclinical and clinical studies.For biologics, ADME studies are usually not required. In this paper, we review the existing approval packages and literature for approved ADCs to determine the extent of ADME studies performed as part of ADC registration packages.We conclude that ADME studies are recommended for the development of ADCs if new linkers and payloads are used that have never been used in humans before as these studies provide valuable information on the pharmacokinetic properties, optimal dosing regimen, and potential safety concerns. However, for the development of ADCs with established linker payload combinations, radiolabelled ADME studies may not be necessary if the distribution, metabolism and excretion properties have been described before. Clinical radiolabelled ADME studies are not recommended where patients are treated for life threating diseases like for indications in oncology.

Native liquid chromatography mass spectrometry (LC-MS) is a commonly used approach for intact analysis of inter-chain cysteine conjugated antibody-drug conjugates (ADCs). Coupling native LC-MS with affinity capture provides a platform for intact ADC analysis from samples and characterisation of individual drug load species, specifically the impact of drug linker deconjugation, hydrolysis, and differential clearance in a biological system.This manuscript describes data generated from native LC-MS analysis of ADCs from human plasma, both incubations and clinical samples. It also details the pharmacokinetic (PK) model built to specifically characterise the disposition of individual drug load species from MMAE and MMAF interchain cysteine conjugated ADCs. deconjugation and hydrolysis rates were similar across both ADCs. Differential clearance of higher loaded species was pronounced for the MMAE conjugated ADC, while systemic elimination after accounting for deconjugation was similar across drug loads for the MMAF conjugated ADC. This is the first report of affinity capture native LC-MS analysis, and subsequent modelling of deconjugation, hydrolysis and clearance rates of individual drug load species using clinical data from cysteine conjugated ADCs.

Antibody drug conjugates are an exciting therapeutic modality that combines the targeting specificity of antibodies with potent cytotoxins to selectively kill cancer cells. The targeting component improves efficacy and protects non-target cells from the harmful effects of the payload. To date 15 ADCs have been approved by regulatory agencies for commercial use and shown to be valuable tools in the treatment of cancer.The assembly of an ADC requires the chemical ligation of a linker-payload to an antibody. Conventional conjugation methods targeting accessible lysines and cysteines have produced all the ADCs currently on the market. While successful, technologies aiming to improve the homogeneity and stability of ADCs are being developed and tested.Here we provide a review of developing methods for ADC construction. These include enzymatic methods, oligosaccharide remodelling, and technologies using genetic code expansion techniques. The virtues and limitations of each technology are discussed.Emerging conjugation technologies are being applied to produce new formats of ADCs with enhanced functionality including bispecific ADCs, dual-payload ADCs, and nanoparticles for targeted drug delivery. The benefits of these novel formats are highlighted.