Differences In Pharmacokinetics Research Articles

Sex specific considerations in cardiovascular drug therapy.

Despite major advances in cardiac research over the past three decades, cardiovascular disease (CVD) still remains the leading cause of morbidity and mortality in women and men worldwide. However, a major challenge for health care providers is that the current guidelines for cardiovascular drug therapies do not consider the impact of sex in the development of treatment plan for optimizing therapies for women. Clinical research in recent years suggests significant pharmacological and pharmacokinetic differences between females and males which have been attributed in part to differences in body composition, plasma protein binding capacity, drug metabolism and excretion. Herein, we provide a comprehensive review regarding sex- specific differences and drugs commonly used for cardiovascular diseases in women and men. Understanding how sex related differences influence drug efficacy and cardiovascular disease outcomes is crucial for not only optimizing treatment strategies for women and men but to encourage the implementation of specific guidelines that address sex difference as a consideration for treatment of cardiovascular diseases.

Italian Association of Hospital Cardiologists Position Paper 'Gender discrepancy: time to implement gender-based clinical management'.

It has been well assessed that women have been widely under-represented in cardiovascular clinical trials. Moreover, a significant discrepancy in pharmacological and interventional strategies has been reported. Therefore, poor outcomes and more significant mortality have been shown in many diseases. Pharmacokinetic and pharmacodynamic differences in drug metabolism have also been described so that effectiveness could be different according to sex. However, awareness about the gender gap remains too scarce. Consequently, gender-specific guidelines are lacking, and the need for a sex-specific approach has become more evident in the last few years. This paper aims to evaluate different therapeutic approaches to managing the most common women's diseases.

Fabrication of carrier-free heterodimeric nano-prodrugs with podophyllotoxin and SN-38 for a co-delivery system

Combination therapies are gaining interest, as they are expected to improve the pharmacological effects. However, current drug combination therapies involve the administration of individual drugs together, which results in differences in delivery efficiency to tumor tissues owing to differences in pharmacokinetics. In the present study, we developed heterodimeric nano-prodrugs (NPDs). We designed a heterodimer of podophyllotoxin and SN-38, from which an NPD with a particle size of approximately 50 nm and a high dispersion stability was fabricated. Our findings contribute to the development of next-generation drug delivery systems capable of co-delivering multiple anticancer agents.

Sex and the Kidney Drug-Metabolizing Enzymes and Transporters: Are Preclinical Drug Disposition Data Translatable to Humans?

Cross-species differences in drug transport and metabolism are linked to poor translation of preclinical pharmacokinetic and toxicology data to humans, often resulting in the failure of new chemical entities (NCEs) during clinical drug development. Specifically, inaccurate prediction of renal clearance and renal accumulation of NCEs due to differential abundance of enzymes and transporters in kidneys can lead to differences in pharmacokinetics and toxicity between experimental animals and humans. We carried out liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based protein quantification of 78 membrane drug-metabolizing enzymes and transporters (DMETs) in the kidney membrane fractions of humans, rats, and mice for characterization of cross-species and sex-dependent differences. In general, majority of DMET proteins were higher in rodents than in humans. Significant cross-species differences were observed in 30 out of 33membrane DMET proteins quantified in all three species. Although no significant sex-dependent differences were observed in humans, the abundance of 28 and 46 membrane proteins showed significant sex dependence in rats and mice, respectively. These cross-species and sex-dependent quantitative abundance data are valuable for gaining a mechanistic understanding of drug renal disposition and accumulation. Further, these data can also be integrated into systems pharmacology tools, such as physiologically based pharmacokinetic models, to enhance the interpretation of preclinical pharmacokinetic and toxicological data.

Evaluation of gender differences in the pharmacokinetics of oral zileuton nanocrystalline formulation using a rat model

Zileuton is a leukotriene inhibitor used to treat asthma. As a BCS class II drug it exhibits challenges with solubility which likely impact its absorption. As patient gender significantly impacts the pharmacokinetics of many drugs, this study aimed to investigate potential gender-based pharmacokinetic differences after oral zileuton administration in rats. Male and female Sprague Dawley rats received single oral gavage doses of pure zileuton as an active pharmaceutical ingredient (30 mg/kg body weight (bw)), physical mixture (PM; at 30 mg/kg bw of the formulation contains zileuton, kollidon VA64 fine, dowfax2A1 and trehalose), and nanocrystalline formulation of zileuton (NfZ; at 30 mg/kg bw of the formulation). Plasma, tissue, and urine concentrations were quantified using high performance liquid chromatography (HPLC). Noncompartmental pharmacokinetic analysis showed higher zileuton levels in the plasma of female versus male rats across all evaluated forms of zileuton (API, PM, and NfZ). Female rats demonstrated higher peak plasma concentrations (Cmax) and increased area under the plasma concentration-time curve (AUC) relative to males, regardless of formulation. These findings reveal substantial gender disparities in the pharmacokinetics of zileuton in the rat model. This study emphasizes the critical need to evaluate gender differences during preclinical drug development to enable gender-based precision dosing strategies for equivalent efficacy/safety outcomes in male and female patients. Additional studies are warranted to investigate underlying mechanisms of such pharmacokinetic gender divergences.

Sex differences in the prognostic role of achieving target doses of heart failure medications: Data from the Swedish Heart Failure Registry.

Guidelines recommend target doses (TD) of heart failure (HF) with reduced ejection fraction (HFrEF) medications regardless of sex. Differences in pharmacokinetics and pharmacodynamics may explain heterogeneity in treatment response, adverse reactions, and tolerability issues across sexes. The aim of this study was to explore sex-based differences in the association between TD achievement and mortality/morbidity in HFrEF. Patients with HFrEF and HF duration ≥6 months registered in the Swedish HF Registry between May 2000 and December 2020 (follow-up until December 2021) were analysed. Treatments of interest were renin-angiotensin system inhibitors (RASI) or angiotensin receptor-neprilysin inhibitors (ARNI), and beta-blockers. Multivariable Cox regression models were performed to explore the risk of cardiovascular mortality or hospitalization for HF across dose categories in females versus males. A total of 17 912 patients were analysed (median age 77.0 years, interquartile range [IQR] 70.0-83.0), 29% were female. Over a median follow-up of 1.33 years (IQR 0.29-3.22), for RASI/ARNI there was no significant difference in outcome for females achieving 50-99% versus 100% of TD (hazard ratio 0.92, 95% confidence interval 0.83-1.03), whereas males showed a gradual lowering in risk together with the achievement of higher % of TD (p-interaction = 0.030). For beta-blockers the achievement of TD was associated with the lowest risk of outcome regardless of sex. Our findings suggest that females and males might differently benefit from the same dose of RASI/ARNI, and do represent a general call for randomized controlled trials to consider sex-specific up-titration schemes when testing HFrEF treatments in need of up-titration.

Abstract PO3-29-04: Patient selection for high RSK2 expression is key for achieving improved PFS in metastatic breast cancer in the PMD-026 Phase 1/1b study

Abstract Background: PMD-026 is a first in class, reversible, oral small molecule inhibitor of p90 ribosomal S6 kinase (RSK), a kinase family activated by the MAPK and PDK-1 pathways, which regulate substrates involved in cancer cell proliferation and drug resistance. Both pathways are implicated in HR+ and triple negative breast cancer (TNBC). RSK2 can modulate the growth of breast cancer (BC) by promoting cell cycle progression through G2/M, specifically through pYB-1S102 which nucleates spindle pole formation in M-phase of cancer cells. This mechanism of action (MOA) for PMD-026 can be monitored by measuring the loss of pYB-1S102 and pCDK2Y15, a marker for G2/M arrest. Therefore, PMD-026 presents a novel mechanism to inhibit resistance at G1/S which is common for CDK4/6 inhibitors as well as ADCs such as those that contain Topoisomerase 1 conjugates. Here in, we show for the first time that PMD-026 inhibits P-YB-1S102 and pCDK2y15 in a dose-dependent manner in TNBC cells and address whether this could be translated as a pharmacodynamic marker of PMD-026 activity in patients. To guide patient selection, we are co-developing a unique and simple IHC based companion diagnostic (CDx) with Roche based on the principle that activated RSK2 translocates from the cytoplasm into the nucleus. In mBC, RSK2 was found to be highly expressed in ~70% of patients using a staining algorithm. An H-score was developed and ultimately H-score >180 (75% nuclear staining with staining intensity of 2+ or 3+ by IHC) was used as the cut-off in our Phase 1/1b trial retrospective study. This IHC assay will be used to select patients in the upcoming Phase II, as PFS in the PMD-026 Phase I/1b study showed remarkable differences when comparing patients with high and low RSK2. Results: In this Phase 1/1b study, PMD-026 was evaluated in an ethnically diverse population of women across all breast cancer subtypes. Patients had a median of 5 prior lines of therapy and PMD-026 achieved stable disease in 44% (11/25) of the subjects. Consistent with the MOA, PMD-026 inhibited pCDK2Y15 in PBMCs from patients at C1D15. Corresponding plasma concentrations were ~ 1µM, which correlates with the IC90 of PMD-026 in preclinical models. To guide patient selection in the future, the RSK2 IHC with an H:Score >180 was used to evaluate patient outcomes. Using this criterion, PFS was significantly longer in RSK2 high vs low patients (3.6 months vs 1.3 month, HR = 0.27, p = 0.031, N=20 patients representing de novo TNBC and HR+/CDK4/6 refractory subtypes). Upon further analysis, patients who had 5 lines of therapy or less benefited the most. PFS in these less heavily pretreated RSK2 high patients was 4.8 months vs 1.3 months for RSK2 low patients (HR = 0.07, p = 0.001 N=14 representing the same subtypes above). It was clear that the time on study was longer for patients with high RSK2 vs low, and this was specifically noted in de novo TNBC and HR+ patients that previously failed CDK4/6 inhibitors as well as endocrine therapies. A key observation in this study was that the PFS benefit was based on the RSK2 levels and not on any pharmacokinetic differences between patients, as the AUC (p=0.53), Cmax (p=0.73) and plasma levels (p=0.76) did not differ between RSK2 high and RSK2 low groups. These data strongly support the activity of this first in class RSK inhibitor, PMD-026, in RSK2 high breast cancers. Our integrated IHC based CDx strategy plans to prospectively enroll RSK2 high patients for our Phase 2 trials will be described. Conclusions/Translational Significance: CDx guided breast cancer therapeutics are often lacking for the treatment of TNBC, as well as HR+ breast cancers that have failed CDK4/6 inhibitors. The ability to identify patients who could potentially benefit most from RSK-targeted agents such as PMD-026 is an important step forward in delivering practice changing therapies for patients. Citation Format: Sandra Dunn, Judy Wang, Hyo Han, Robert Wesolowski, Amita Patnaik, Shakeela Bahadur, Nicolaos Palaskas, My-my Huynh, Aarthi Jayanthan, Gerrit Los, Andrew Dorr. Patient selection for high RSK2 expression is key for achieving improved PFS in metastatic breast cancer in the PMD-026 Phase 1/1b study [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-29-04.

Abstract PO3-18-05: Pharmacokinetics (PK) of lasofoxifene (LAS) monotherapy and combined with abemaciclib (Abema)

Abstract Introduction: LAS is a selective estrogen receptor modulator (SERM)/tissue-selective estrogen agonist/antagonist studied in women with osteoporosis and vulvar-vaginal atrophy, and most recently, metastatic breast cancer (mBC) with ESR1 mutations. LAS data in healthy postmenopausal women and young men show linear PK and no differences by age or race (Gardner. J Clin Pharmacol 2006;46:52-58; Prakash. Drug Metab Dispos 2008;26:1218-26; Data on file). Also, no PK differences were found between Caucasian and Japanese patients (Jhee. AACR-JCA 2022, abstract A83; Fountaine. J Clin Pharmacol 2006;46:693-99). Here we report select PK data of LAS (5 mg/day) from women with mBC in the ELAINE 1 and ELAINE 2 oncology trials to indirectly investigate possible drug-drug interactions between LAS and Abema. Methods: Patients with mBC and ESR1 mutations who progressed on endocrine therapy and CDK4/6 inhibitors received LAS 5 mg/day as monotherapy (ELAINE 1) or combined with Abema (provided by Eli Lilly and Co) 150 mg BID (ELAINE 2). Blood was collected prior to daily dosing at weeks 2, 4, 8, and every 4 weeks up to the final visit in ELAINE 1, and visits during the first 8 weeks in ELAINE 2, to determine the plasma trough steady-state concentrations (Css) of LAS, Abema, and two active Abema metabolites (M2 and M20). LAS was assayed using validated high-performance liquid chromatography/tandem mass spectrometry (LC/MS/MS; detection 0.025 to 25.0 ng/mL); levels below the lower limit of quantification (LLOQ) were reported as 0 ng/mL. Abema and its M2 and M20 metabolites were measured by validated Turbo Ion Spray LC/MS/MS (detection 1.00 to 500 ng/mL); values below the LLOQ were reported as < LLOQ ng/mL. Mean trough Css at each visit were calculated for LAS (ELAINE 1 and 2), and Abema and its M2 and M20 metabolites (ELAINE 2). LAS levels from ELAINE 1 and 2 were compared, while Abema, M2 and M20 plasma levels in ELAINE 2 were compared with previously reported levels. Such indirect comparisons may help determine if Abema altered the metabolism of LAS, or if LAS altered that of Abema, M2, or M20. The relationships of LAS and Abema levels with progression-free survival (PFS) were also explored. Results: Across all time points for subjects who had PK samples assessed, the LAS mean trough Css was 33.6 ng/mL (CV%, 39.8) in ELAINE 1 (n=40) and 30.9 ng/mL (CV 50.5%) in ELAINE 2 (n=29); in both studies, LAS concentrations were consistent across visits. LAS levels in ELAINE 2 were similar to those in ELAINE 1 with no evidence of accumulation. Mean (CV%) Abema plasma concentrations at weeks 2, 4, 6 and 8 were 199 (102%), 107 (130%), 82 (271%), and 94.3 (223%) ng/mL, respectively. Minimum and maximums of the mean trough Css for LAS, Abema, M2, and M20 are shown in Table 1. No relationships between LAS or Abema levels and antitumor activity measured by PFS were seen (data to be presented). Conclusion: The steady-state PK of 5 mg LAS in the ELAINE 1 and 2 studies suggest that the addition of abemaciclib to LAS did not result in an obvious or significant LAS-Abema, drug-drug interaction. Abema PK data from ELAINE 2 were consistent with published data (European Medicines Agency, Verzenio). These results support the continued development of LAS alone and combined with Abema for treating ER+/HER2-, ESR1-mutated mBC that progressed on endocrine therapy and CDK4/6 inhibitors. Table. Mean trough, steady-state concentrations of lasofoxifene and abemaciclib. XX- XX aData from patients who received oral LAS (5 mg/day) plus Abema (150 mg BID). Abema, abemaciclib; LAS, lasofoxifene; M2 and M20 are Abema metabolites. Citation Format: Senthil Damodaran, Paul V. Plourde, Simon Jenkins, Phil Mayer, David J Portman, Matthew Goetz. Pharmacokinetics (PK) of lasofoxifene (LAS) monotherapy and combined with abemaciclib (Abema) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-18-05.

Biomarkers predicting the effect of anti-TNF treatment in paediatric and adult inflammatory bowel disease.

Paediatric and adult inflammatory bowel disease (pIBD, aIBD) patients may lose response to anti-TNF treatment within the first year. Adult-extrapolated weight-based dosing is incorrect in children, due to age-related pharmacokinetic differences. We investigated biomarkers for initial and maintenance of response to infliximab (IFX) or adalimumab (ADA), comparing pIBD and aIBD patients. In this prospective, observational study, pIBD (n = 24) and aIBD (n = 21) patients were included when initiating anti-TNF. Escalation from standard dosing and continued anti-TNF at 12 and 18 months were assessed. Biomarkers included clinical laboratory parameters, faecal calprotectin (FCP) and IFX trough levels (TLs). Plasma proteomics was performed in pIBD. During our study, treatment escalation (in clinical loss of response) occurred more common in pIBD versus aIBD (p = 0.02). We established that IFX therapy escalation in pIBD patients was not due to low infliximab levels. We identified 9 pro-inflammatory proteins that were elevated in patients losing response. Anti-TNF exposure-response relationship may be different in pIBD versus aIBD. No biomarkers for maintained response were identified, but 9 inflammatory proteins were of interest as potential predictors for loss of response in pIBD.

Comparative Bleeding Risk of Brand Vs Generic Rivaroxaban in Elderly Inpatients with Atrial Fibrillation.

Atrial fibrillation (AF) is the most common abnormal heart rhythm in elderly patients. Rivaroxaban has been widely used for stroke prevention. The anticoagulant response to rivaroxaban increases with age, which may make elderly patients susceptible to adverse outcomes resulting from small differences in bioavailability between generic and brand products. We designed a cohort study of ≥65-year-old inpatients with AF. Sociodemographic and laboratory measures of qualified patients who received brand or generic rivaroxaban for at least 72 hours at the study hospital from January 2021 to June 2023 were collected retrospectively. The primary outcome was the incidence of bleeding. A total of 1008 qualifying patients were included for analysis, with 626 (62.1%) receiving brand rivaroxaban and 382 (37.9%) receiving generic rivaroxaban. After propensity score matching and weighting to account for confounders, the odds ratios comparing brand vs generic rivaroxaban (95% confidence intervals) for the bleeding was 1.15 (0.72-1.82). Results from subgroup analyses of patients with age ≥85, HAS-BLED score ≥3, containment of antiplatelet drugs, and female patients were consistent with the primary analysis. It provides evidence regarding the clinical safety outcome of generic rivaroxaban in the elderly AF population that may be particularly susceptible to adverse outcomes resulting from small allowable differences in pharmacokinetics.

Left-Right Difference in Brain Pharmacokinetics Following Nasal Administration Via One-Site Nostrils

The olfactory and trigeminal pathways are direct delivery pathways between the nose and brain. To determine the effect of direct delivery on drug distribution in the brain, two model drugs with different physical properties, antipyrine (ANP), with high membrane permeability, and ranitidine (RNT), with low membrane permeability, were selected. For ANP, direct delivery from the nose to the brain was observed only in the olfactory bulb beside the nasal cavity, with a direct transport percentage (DTP) of approximately 45 %, whereas in the frontal and occipital brains, the contribution from the systemic circulation to the brain was observed as the primary route of brain distribution. No significant variations were observed in the pharmacokinetics of ANP in the left and right brain, whereas RNT was distributed in all brain regions with a DTP of > 95 %. The closer the brain region is to the nasal cavity, the higher the DTP. Furthermore, the left brain, the same nostril site (left nostril) of administration, had a larger level of drug delivery than the right brain. These findings imply that the influence of the administered nostril site differs based on the physicochemical properties and amount of the drug.

A high performance liquid chromatography-tandem mass spectrometry assay for therapeutic drug monitoring of 10 drug compounds commonly used for antimicrobial therapy in plasma and serum of critically ill patients: Method optimization, validation, cross-validation and clinical application

Background and aimsIntensive care antibiotic treatment faces challenges due to substantial pharmacokinetic differences in critically ill patients. Individualized antibiotic dosing guided by therapeutic drug monitoring (TDM) is considered to minimize the risk of treatment failure and toxicity. This study aimed to develop a valid method for simultaneous LC-MS/MS quantification of 10 drugs frequently used in intensive care antibiotic therapy for which TDM-guided dosing is recommended: piperacillin, meropenem, flucloxacillin, cefuroxime, vancomycin, colistin A and B, linezolid, ciprofloxacin and tazobactam. Methods and ResultsThorough optimization of sample preparation and chromatography resulted in a fast and simple method based on protein precipitation of 50 µL plasma or serum and gradient elution using an Acquity UPLC HSS-T3 column. Electrospray ionization-triple quadrupole mass spectrometry in dynamic multiple reaction monitoring was used for quantification, covering the therapeutic range of each drug compound. Validation following EMA and FDA recommendations, including inter-platform validation and inter-laboratory comparison, demonstrated high accuracy, precision and robustness of the new method. The assay was successfully used to monitor plasma antibiotic levels of critically ill patients (n = 35). ConclusionThe established multiplex method covers major drug classes with documented dosing challenges, provides a reliable basis for the implementation of high-throughput TDM, and its application confirmed the clinical impact of TDM in a real-world setting.

Impact of Viloxazine Extended-Release Capsules (Qelbree®) on Select Cytochrome P450 Enzyme Activity and Evaluation of CYP2D6 Genetic Polymorphisms on Viloxazine Pharmacokinetics.

Viloxazine extended-release (ER) [Qelbree®] is a nonstimulant attention-deficit/hyperactivity disorder (ADHD) treatment. In vitro studies suggested potential for viloxazine to inhibit cytochrome450 (CYP) enzymes 1A2, 2B6, 2D6 and 3A4. This clinical study therefore evaluated viloxazine ER effects on index substrates for CYP1A2, 2D6, and 3A4, and secondarily evaluated the impact of CYP2D6 polymorphisms on viloxazine pharmacokinetics. Thirty-seven healthy subjects received a modified Cooperstown cocktail (MCC; caffeine 200mg, dextromethorphan 30mg, midazolam 0.025 mg/kg) on Day 1, viloxazine ER 900 mg/day on Days 3-5, and a combination of viloxazine ER 900 mg and MCC on Day 6. Viloxazine ER effects on MCC substrates were evaluated using analysis of variance. The impact of CYP2D6 genetic polymorphisms on steady-state viloxazine plasma concentrations was evaluated using Student's t test assessing pharmacokinetic parameter differences between poor versus extensive metabolizers. The least squares geometric mean ratio [GMR%] (90% CI) of MCC substrate + viloxazine ER/MCC substrate alone for caffeine maximum concentration (Cmax), area under the plasma concentration-time curve from time 0 to the last quantifiable concentration (AUCt), and area under the plasma concentration-time curve from time 0 extrapolated to infinity (AUC∞) was 99.11 (95.84-102.49), 436.15 (398.87-476.92), and 583.35 (262.41-1296.80), respectively; 150.76 (126.03-180.35), 185.76 (155.01-222.61), and 189.71 (160.37-224.42) for dextromethorphan Cmax, AUCt, and AUC∞, respectively; and 112.81 (104.71-121.54), 167.56 (153.05-183.45), and 168.91 (154.38-184.80) for midazolam Cmax, AUCt, and AUC∞, respectively. At steady state, viloxazine least squares GMR (90% CI) for poor/extensive CYP2D6 metabolizers were Cmax 120.70 (102.33-142.37) and area under the plasme concentration-time curve from time 0 to 24 hours (AUC0-24 125.66 (105.36-149.87)). Viloxazine ER is a strong CYP1A2 inhibitor and a weak CYP2D6 and CYP3A4 inhibitor. CYP2D6 polymorphisms did not meaningfully alter the viloxazine ER pharmacokinetic profile.

Iodine-induced synthetic method and pharmacokinetic study of cis- and trans-crocetin.

This experiment aimed to obtain the relatively rare cis-crocetin isomer from natural plants, which predominantly exist in the more stable all-trans configuration. This was achieved through iodine-induced isomerization, followed by purification and structural identification. The study also aimed to compare the pharmacokinetic differences between cis- and trans-crocetin in vivo. Trans-crocetin of high purity was extracted by hydrolysis from gardenia yellow pigment. Cis-crocetin was then synthesized through an optimized electrophilic addition reaction induced by elemental iodine, and subsequently separated and purified via silica gel column chromatography. Structural identification of cis-crocetin was determined using IR, UV, and NMR techniques. In vivo pharmacokinetic studies were conducted for both cis- and trans-crocetin. In addition to this, we have conducted a comparative study on the in vivo anti-hypoxic activity of trans- and cis-crocetin. Under the selected reaction conditions using DMF as the solvent, with a concentration of 2.5mg/mL for both trans-crocetin and the iodine solution, and adjusting the illumination time according to the amount of trans-crocetin, the rate of iodine-induced isomerization was the fastest. Cis-crocetin was successfully obtained and, after purification, its structure was identified and found to be consistent with reported data. Cis-crocetin exhibited a faster absorption rate and higher bioavailability, and despite its shorter half-life, it could partially convert to trans-crocetin in the body, thereby extending the duration of the drug's action within the body to some extent. This study accomplished the successful preparation and structural identification of cis-crocetin. Additionally, through pharmacokinetic studies, it uncovered notable variations in bioavailability between cis- and trans-crocetin. These findings serve as a solid scientific foundation for future functional research and practical applications in this field.

Diagnosis and therapy of patients with asthma in Germany. Results of the care study RELEVANT

Diagnostic and therapeutic options for asthma have improved with asthma control and remission being of central importance. The RELEVANT study aimed for a nationwide snapshot of current asthma diagnosis and treatment in general practice and specialty care for identification of further aspects for optimization. RELEVANT is a nationwide cross-sectional study using a structured questionnaire. This comprised 14 questions on asthma-related topics covering diagnostics and therapy. Participants were general practitioners/internal medicine specialists and pulmonologists. A total of 1,558 persons took part in the survey. Regarding relevant specific diagnostic procedures for asthma, GPs/internists almost exclusively mentioned pulse oximetry. Among the pulmonologists, fractional exhaled nitric oxide (FeNO) measurement was mentioned, among others. FeNO and blood eosinophils were only mentioned by the pulmonologists as diagnostic and treatment-relevant markers. A total of more than 60% of the GPs/internists surveyed stated that only around 25% or fewer of their patients would voluntarily report restrictions in their everyday lives. Regarding drug treatment, the majority stated that they recognized differences between various ICS/LABA combination therapies. The results indicate a need for optimization, particularly regarding asthma control. This involves both a better assessment by patients' everyday life restrictions and modern ways of assessing asthma control in cooperation between GPs/internal medicine specialists and pulmonologists. One fifth of respondents do not see any differences between various ICS/LABA combinations in daily practice, although there are pharmacodynamic and pharmacokinetic differences.

Clinical Pharmacology of the Antibody-Drug Conjugate Enfortumab Vedotin in Advanced Urothelial Carcinoma and Other Malignant Solid Tumors.

Enfortumab vedotin is an antibody-drug conjugate comprised of a human monoclonal antibody directed to Nectin-4 and monomethyl auristatin E (MMAE), a microtubule-disrupting agent. The objectives of this review are to summarize the clinical pharmacology of enfortumab vedotin monotherapy and demonstrate that the appropriate dose has been selected for clinical use. Pharmacokinetics (PK) of enfortumab vedotin (antibody-drug conjugate and total antibody) and free MMAE were evaluated in five clinical trials of patients with locally advanced or metastatic urothelial carcinoma (n=748). Intravenous enfortumab vedotin 0.5-1.25 mg/kg on days 1, 8, and 15 of a 28-day cycle showed linear, dose-proportional PK. No significant differences in exposure or safety of enfortumab vedotin and free MMAE were observed in mild, moderate, or severe renal impairment versus normal renal function. Patients with mildly impaired versus normal hepatic function had a 37% increase in area under the concentration-time curve (0-28 days), a 31% increase in maximum concentration of free MMAE, and a similar adverse event profile. No clinically significant PK differences were observed based on race/ethnicity with weight-based dosing, and no clinically meaningful QT prolongation was observed. Concomitant use with dual P-glycoprotein and strong cytochrome P450 3A4 inhibitors may increase MMAE exposure and the risk of adverse events. Approximately 3% of patients developed antitherapeutic antibodies against enfortumab vedotin 1.25 mg/kg. These findings support enfortumab vedotin 1.25 mg/kg monotherapy on days 1, 8, and 15 of a 28-day cycle. No dose adjustments are required for patients with renal impairment or mild hepatic impairment, or by race/ethnicity.

Age-related pharmacokinetics differences were observed between young and elderly populations of a novel PDE5 inhibitor, youkenafil, and its metabolite M459

PurposeYoukenafil is a novel oral selective PDE5 inhibitor for treating Erectile Dysfunction. This investigation assessed pharmacokinetics (PK), safety, and tolerability of youkenafil and its main metabolite (M459) after taking 100 mg youkenafil hydrochloride tablets in elderly and young subjects. MethodsThis Phase I, single-center, open-label, parallel-group, single-dose study was conducted on 24 individuals (12 elders and 12 youngsters). Each subject received a single oral 100 mg youkenafil hydrochloride tablets. Blood samples were collected before medication and up to 48 h after medication for PK analysis. Safety and tolerability were also assessed, including treatment-emergent adverse events (TEAEs), laboratory tests, 12-lead ECG, vital sign inspections, color vision examinations, and physical examinations. ResultsPlasma concentrations of youkenafil and M459 were quantified. PK parameters were determined by non-compartmental analysis. Median Tmax of elderly and young groups were both 0.733 h. However, Cmax, AUC0-t, and AUC0-∞ of youkenafil were separately 16.8 %, 37.2 %, and 37.5 % higher in elders and t1/2 of youkenafil was 2.1 h longer in elders. More great differences were observed for M459. T1/2 values were 4.05 h longer in elders, with Cmax, AUC0-t and AUC0-∞ 73.7 %, 81.1 %, and 81.4 % higher in elders. Two (8.3 %) elderly subjects reported TEAEs (all grade Ⅰ in severity) and both recovered without any treatment. No serious adverse reactions (SAEs) or serious unexpected suspected adverse reactions (SUSARs) occurred in this study. ConclusionsThis was the first PK research of youkenafil and M459 in elderly men. PK parameters differences between youkenafil and M459 were comparable between elderly and young groups. Moreover, safety and tolerability of youkenafil were favorable in both groups.

Kinetic modeling of the plasma pharmacokinetic profiles of ADAMTS13 fragment and its Fc-fusion counterpart in mice.

Introduction: Fusion of the fragment crystallizable (Fc) to protein therapeutics is commonly used to extend the circulation time by enhancing neonatal Fc-receptor (FcRn)-mediated endosomal recycling and slowing renal clearance. This study applied kinetic modeling to gain insights into the cellular processing contributing to the observed pharmacokinetic (PK) differences between the novel recombinant ADAMTS13 fragment (MDTCS) and its Fc-fusion protein (MDTCS-Fc). Methods: For MDTCS and MDTCS-Fc, their plasma PK profiles were obtained at two dose levels following intravenous administration of the respective proteins to mice. The plasma PK profiles of MDTCS were fitted to a kinetic model with three unknown protein-dependent parameters representing the fraction recycled (FR) and the rate constants for endocytosis (kup, for the uptake into the endosomes) and for the transfer from the plasma to the interstitial fluid (kpi). For MDTCS-Fc, the model was modified to include an additional parameter for binding to FcRn. Parameter optimization was done using the Cluster Gauss-Newton Method (CGNM), an algorithm that identifies multiple sets of approximate solutions ("accepted" parameter sets) to nonlinear least-squares problems. Results: As expected, the kinetic modeling results yielded the FR of MDTCS-Fc to be 2.8-fold greater than that of MDTCS (0.8497 and 0.3061, respectively). In addition, MDTCS-Fc was predicted to undergo endocytosis (the uptake into the endosomes) at a slower rate than MDTCS. Sensitivity analyses identified the association rate constant (kon) between MDTCS-Fc and FcRn as a potentially important factor influencing the plasma half-life in vivo. Discussion: Our analyses suggested that Fc fusion to MDTCS leads to changes in not only the FR but also the uptake into the endosomes, impacting the systemic plasma PK profiles. These findings may be used to develop recombinant protein therapeutics with extended circulation time.

Clinical outcomes of colistin methanesulfonate sodium in correlation with pharmacokinetic parameters in critically ill patients with multi-drug resistant bacteria-mediated infection: A systematic review and meta-analysis

BackgroundColistin is a viable option for multidrug resistant gram-negative bacteria emerged from inappropriate antibiotic use. Nonetheless, suboptimal colistin concentrations and nephrotoxicity risks hinder its clinical use. Thus, the aim of this study is to investigate clinical outcomes in correlation with pharmacokinetic differences and infection types in critically ill patients on intravenous colistin methanesulfornate sodium (CMS). MethodsA systematic literature search of Embase, Google Scholars, and PubMed was performed to identify clinical trials evaluating pharmacokinetic parameters along with clinical outcomes of CMS treatment from inception to July 2023. The pooled analyses of clinical impact of CMS on nephrotoxicity, mortality, clinical cure, and colistin concentration at steady state (Css,avg) were performed. This study was registered in the PROSPERO (CRD 42023456120). ResultsTotal of 695 critically ill patients from 17 studies were included. The mortality was substantially lower in clinically cured patients (OR 0.05; 95% CI 0.02 – 0.14), whereas the mortality rate was statistically insignificant between nephrotoxic and non-nephrotoxic patients. Inter-patient variability of pharmacokinetic parameters of CMS and colistin was observed in critically ill patients. The standard mean differences of Css,avg were statistically insignificant between clinically cure and clinically failure groups (standard mean difference (SMD) −0.25; 95% CI −0.69 – 0.19) and between nephrotoxic and non-nephrotoxic groups (SMD 0.67; 95% CI −0.27–1.61). The clinical cure rate is substantially lower in pneumonia patients (OR 0.09; 95% CI 0.01 – 0.56), and pharmacokinetic parameters pertaining to microbiological cure were different among strains. ConclusionThe mortality rate was substantially lower in clinically cured patients with CMS. However, no significant differences in Css,avg of colistin were examined to determine the impact of pharmacokinetic differences on clinical outcomes including mortality rate and nephrotoxicity risk. Nevertheless, the clinical cure rate is substantially lower in patients with respiratory infection than patients with urinary tract infection.

The effect of liver dysfunction on the pharmacokinetic disposition of belinostat and its five metabolites in patients with advanced cancers.

Belinostat was approved in 2014 for the treatment of relapsed or refractory peripheral T-cell lymphoma, however, there was insufficient data to recommend a dose in patients with moderate to severe hepatic impairment. The purpose of this analysis was to characterize the pharmacokinetic disposition of belinostat and its five metabolites in patients with advanced cancers and varying degrees of liver dysfunction. A population pharmacokinetic model was therefore developed to describe the parent-metabolite system. The final model was then implemented to assess the effect of liver impairment on each metabolic pathway of belinostat. It was determined that significant pharmacokinetic differences could only be demonstrated in patients with severe hepatic impairment. The final model estimated a 35%-47% reduction in metabolic clearance attributed to UGT1A1/2B7 glucuronidation, CYP2A6/3A4/2C9 metabolism, and β-oxidation. These hepatic impairment effects reduced between-subject variability by only 5%-8% for their respective parameter, with a large amount of remaining unexplained variability. With further validation, this model can be leveraged to assess the need for dose adjustments in this patient population.