Dosing Regimens In Patients Research Articles

Pharmacokinetics of Vancomycin in Healthy Korean Volunteers and Monte Carlo Simulations to Explore Optimal Dosage Regimens in Patients with Normal Renal Function.

Background/Objectives: To date, population pharmacokinetic (PK) studies of vancomycin on healthy Korean adults have not been conducted. This study aimed to investigate the PK properties of vancomycin in healthy volunteers and to identify optimal dosing regimens based on the area under the concentration-time curve (AUC) in adult patients with normal renal function. Methods: We conducted a prospective clinical study, analysing PK samples from 12 healthy participants using noncompartmental analysis and non-linear mixed-effects modelling. The population PK parameters derived were employed in Monte Carlo simulations to evaluate the adequacy of the current dosing regimen and to formulate dosing recommendations. Results: The PK profiles were optimally described by a two-compartment model, with body weight and age as significant covariates affecting total clearance. The simulations indicated that to achieve a therapeutic target-defined as an AUC at steady-state over 24 h of 400-600 mg·h/L-daily doses ranging from 60 to 70 mg/kg are necessary in adults with normal renal function. Conclusions: This study underscores the need to actively adjust dosage and administration based on a vancomycin PK model that adequately reflects the demographic characteristics of patients to meet both safety and efficacy standards.

A loading dose of clofazimine to rapidly achieve steady-state-like concentrations in patients with nontuberculous mycobacterial disease.

Clofazimine is a promising drug for the treatment of nontuberculous mycobacterial (NTM) diseases. Accumulation of clofazimine to reach steady-state plasma concentrations takes months. A loading dose may reduce the time to steady-state-like concentrations. We evaluated the pharmacokinetics (PK), safety and tolerability of a loading dose regimen in patients with NTM disease. Adult participants received a 4-week loading dose regimen of 300 mg clofazimine once daily, followed by a maintenance dose of 100 mg once daily (combined with other antimycobacterial drugs). Blood samples for PK analysis were collected on three occasions. A population PK model for clofazimine was developed and simulations were performed to assess the time to reach steady-state-like (target) concentrations for different dosing regimens. Twelve participants were included. The geometric mean peak and trough clofazimine concentrations after the 4-week loading phase were 0.87 and 0.50 mg/L, respectively. Adverse events were common, but mostly mild and none led to discontinuation of clofazimine. Our loading dose regimen reduced the predicted median time to target concentrations by 1.5 months compared to no loading dose (3.8 versus 5.3 months). Further time benefit was predicted with a 6-week loading dose regimen (1.4 versus 5.3 months). A 4-week loading dose regimen of 300 mg once daily reduced the time to target clofazimine concentrations and was safe and well-tolerated. Extending the loading phase to 6 weeks could further decrease the time to target concentrations. Using a loading dose of clofazimine is a feasible strategy to optimize treatment of NTM disease. NCT05294146.

A Randomized Controlled Trial to Evaluate the Efficacy of Roxadustat Dosing Regimens in Patients with CKD and Anemia on Dialysis

A Randomized Controlled Trial to Evaluate the Efficacy of Roxadustat Dosing Regimens in Patients with CKD and Anemia on Dialysis

Comparing Two Vancomycin Loading Dose Regimens in Patients With Obesity: A Single-Center Prospective Clinical Trial.

Obesity can significantly influence the pharmacokinetics of several medications, including vancomycin. Consequently, specialized dosing strategies may be required to ensure efficacy and safety in patients with obesity(PwO) requiring treatment with vancomycin. This single-center, prospective study evaluated two vancomycin loading dose regimens in PwO, comparing serum vancomycin concentrations, adverse events, and the impact on renal function. Adult patients weighing over 100 kg were randomized into two study groups. A 20 mg/kg loading dose of vancomycin was administered to both groups, with one group restricted to a maximum dose of 2000 mg (n=33) and the other group receiving up to 4000 mg (n=34). Patients receiving the 4000 mg maximal dose achieved significantly higher median vancomycin concentrations at the initial trough (9.1 mg/L vs. 11.3 mg/L, p=0.0497), mean concentrations at the 7.5-hour interval trough (14.4 mg/L vs. 17.1 mg/L, p=0.0151), and mean concentrations at the post-load peak (23.9 mg/L vs. 30.9 mg/L, p=0.0023), without a corresponding increase in adverse renal outcomes, hospital length of stay, or mortality as compared with the 2000 mg maximum dose group. The study's findings demonstrate that higher vancomycin doses in PwO are safely tolerated and do not result in short-term adverse effects on renal function. This study helps us better understand vancomycin pharmacotherapy in PwO, supporting the need for further research to refine dosing guidelines for these patients.

Population pharmacokinetic analyses of pozelimab in patients with CD55-deficient protein-losing enteropathy (CHAPLE disease).

Pozelimab, a monoclonal antibody directed against C5, is the first and only treatment for adult and pediatric patients (≥ 1 year) with CD55-deficient protein-losing enteropathy (CHAPLE) disease. A target-mediated drug disposition (TMDD) population pharmacokinetic (PopPK) model was developed using pooled data from four phase 1-3 studies to characterize the pharmacokinetics (PK) of total pozelimab and total C5, and to simulate free pozelimab and free C5 to support the dose regimen in patients with CHAPLE disease. A TMDD PopPK model was developed using total pozelimab and total C5 concentration-time data from 106 participants (82 healthy volunteers; 24 patients with paroxysmal nocturnal hemoglobinuria [PNH]). This model was refined and updated to include PK data from 10 patients with CHAPLE disease from a phase 2/3 study. Stochastic simulations predicted concentration-time profiles for total pozelimab, free pozelimab, and free C5, to obtain pozelimab exposure metrics for patients with CHAPLE disease. A two-compartment TMDD model with two binding sites based on the quasi-equilibrium approximation adequately described the concentration-time profiles of total pozelimab and total C5. Body weight was identified as the most important source of pozelimab PK variability; therefore, the dose was adjusted based on body weight for the predominantly pediatric patients with CHAPLE disease. A robust TMDD PopPK model was developed to describe the PK of total pozelimab and total C5 following pozelimab administration. Reliable predictions for individual exposures of total pozelimab and free C5 were possible and supported the 10mg/kg weight-based dose regimen in patients with CHAPLE disease.

Evaluation and application of population pharmacokinetic models for optimising linezolid treatment in non-adherence multidrug-resistant tuberculosis patients

BackgroundPopulation pharmacokinetic (popPK) models can optimise linezolid dosage regimens in patients with multidrug-resistant tuberculosis (MDR-TB); however, unknown cross-centre precision and poor adherence remain problematic. This study aimed to assess the predictive ability of published models and use the most suitable model to optimise dosage regimens and manage compliance. MethodsOne hundred fifty-eight linezolid plasma concentrations from 27 patients with MDR-TB were used to assess the predictive performance of published models. Prediction-based metrics and simulation-based visual predictive checks were conducted to evaluate predictive ability. Individualised remedial dosing regimens for various delayed scenarios were optimised using the most suitable model and Monte Carlo simulations. The influence of covariates, scheduled dosing intervals, and patient compliance were assessed. ResultsSeven popPK models were identified. Body weight and creatinine clearance were the most frequently identified covariates influencing linezolid clearance. The model with the best performance had a median prediction error (PE%) of -1.62 %, median absolute PE of 29.50 %, and percentages of PE within 20 % (F20, 36.97 %) and 30 % (F30, 51.26 %). Monte Carlo simulations indicated that a twice-daily 300 mg linezolid dose may be more efficient than 600 mg once daily. For the ‘typical’ patient treated with 300 mg twice daily, half the dosage should be taken after a delay of ≥ 3 h. ConclusionsMonte Carlo simulations based on popPK models can propose remedial regimens for delayed doses of linezolid in patients with MDR-TB. Model-based compliance management patterns are useful for balancing efficacy, adverse reactions, and resistance suppression.

Pharmacogenetics of warfarin: A literature review

Warfarin is an oral indirect anticoagulant that is widely used for the prevention of thromboembolic events. Pharmacogenetic testing is the most promising approach to personalizing warfarin treatment. In this review, we aimed to summarize how the patients’ genetic predispositions affect the pharmacokinetics of warfarin, which determines the different dosing regimens for patients. To correctly interpret data in clinical settings, algorithms for selecting the optimal dosing regimen need to be developed that consider the patient’s age, sex, weight, height, health status, and genetic characteristics. These algorithms could help determine the optimal dose, enhance patient adherence to treatment, and increase the physician’s confidence in the treatment safety. Furthermore, although algorithms that consider SNPs in the CYP2C9, VKORC1, and CYP4F2 genes are more effective in predicting warfarin doses, their effectiveness varies according to race.

Population pharmacokinetic analysis of zastaprazan (JP-1366), a novel potassium-competitive acid blocker, in patients and healthy volunteers.

Zastaprazan (JP-1366) is a novel potassium-competitive acid blocker for the treatment of acid-related disorders. We aimed to establish a population pharmacokinetic (PK) model of zastaprazan, thereby characterizing the PK of zastaprazan in patients with gastroesophageal reflux disease (GERD) as well as evaluating the impact of various covariates, including CYP2C19 phenotypes, on zastaprazan PK. This population PK analysis included zastaprazan plasma concentration-time data from 92 patients with erosive GERD and 68 healthy volunteers without any gastrointestinal disorders and was performed using nonlinear mixed-effect modeling. Simulations were conducted to predict zastaprazan PK under various dosing regimens in patients with GERD. The plasma PK of zastaprazan was adequately described by a two-compartment model with Erlang-type absorption (six sequential compartments) and first-order elimination. CYP2C19 phenotypes had no significant effect on zastaprazan PK. The disease status was identified as a significant covariate on apparent clearance of zastaprazan, showing lower values in patients with GERD compared to healthy volunteers. However, the model-based simulation indicated that the impact of disease status on zastaprazan exposure was not clinically meaningful. Overall, the current population PK model successfully characterized the observed zastaprazan PK in both patients with GERD and healthy volunteers.

Concentration-QTc modeling of sitravatinib in patients with advanced solid malignancies.

Sitravatinib (MGCD516) is an orally available, small molecule, tyrosine kinase inhibitor that has been evaluated in patients with advanced solid tumors. Concentration-corrected QT interval (QTc; C-QTc) modeling was undertaken, using 767 matched concentration-ECG observations from 187 patients across two clinical studies in patients with advanced solid malignancies, across a dose range of 10-200 mg, via a linear mixed-effects (LME) model. The effect on heart rate (HR)-corrected QT interval via Fridericia's correction method (QTcF) at the steady-state maximum concentration (Cmax,ss) for the sitravatinib proposed therapeutic dosing regimen (100 mg malate once daily [q.d.]) without and with relevant intrinsic and extrinsic factors were predicted. No significant changes in HR from baseline were observed. Hysteresis between sitravatinib plasma concentration and change in QTcF from baseline (ΔQTcF) was not observed. There was no significant relationship between sitravatinib plasma concentration and ΔQTcF. The final C-QTc model predicted a mean (90% confidence interval [CI]) ΔQTcF of 3.92 (1.95-5.89) ms and 2.94 (0.23-6.10) ms at the proposed therapeutic dosing regimen in patients with normal organ function (best case scenario) and patients with hepatic impairment (worst-case scenario), respectively. The upper bounds of the 90% CIs were below the regulatory threshold of concern of 10 ms. The results of the described C-QTc analysis, along with corroborating results from nonclinical safety pharmacology studies, indicate that sitravatinib has a low risk of QTc interval prolongation at the proposed therapeutic dose of 100 mg malate q.d.

Pharmacokinetics of long-acting lenacapavir in participants with hepatic or renal impairment.

Lenacapavir is a novel, first-in-class, multistage inhibitor of HIV-1 capsid function approved for the treatment of multidrug-resistant HIV-1 infection in combination with other antiretrovirals for heavily treatment-experienced people with HIV. Two Phase 1, open-label, parallel-group, single-dose studies assessed the pharmacokinetics (PK) of lenacapavir in participants with moderate hepatic impairment [Child-Pugh-Turcotte (CPT) Class B: score 7-9] or severe renal impairment [15 ≤ creatinine clearance (CLcr) ≤29 mL/min] to inform lenacapavir dosing in HIV-1-infected individuals with organ impairment. In both studies, a single oral dose of 300 mg lenacapavir was administered to participants with normal (n = 10) or impaired (n = 10) hepatic/renal function who were matched for age (±10 years), sex, and body mass index (±20%). Lenacapavir exposures [area under the plasma concentration-time curve from time 0 to infinity (AUCinf) and maximum concentration (Cmax)] were approximately 1.47- and 2.61-fold higher, respectively, in participants with moderate hepatic impairment compared to those with normal hepatic function, whereas lenacapavir AUCinf and Cmax were approximately 1.84- and 2.62-fold higher, respectively, in participants with severe renal impairment compared to those with normal renal function. Increased lenacapavir exposures with moderate hepatic or severe renal impairment were not considered clinically meaningful. Lenacapavir was considered generally safe and well tolerated in both studies. These results support the use of approved lenacapavir dosing regimen in patients with mild (CPT Class A: score 5-6) or moderate hepatic impairment as well as in patients with mild (60 ≤ CLcr ≤ 89 mL/min), moderate (30 ≤ CLcr ≤ 59 mL/min), and severe renal impairment.

Development of a target concentration intervention to individualize paroxysmal nocturnal hemoglobinuria treatment with pegcetacoplan

Pegcetacoplan (Aspaveli®/Empaveli™) is a factor C3 inhibitor that is approved for the treatment of paroxysmal nocturnal hemoglobinuria. An individualized dosing strategy might be useful to improve patient-friendliness and cost-effectiveness of this very expensive drug. Therefore, the aim of this study was to develop an individualized treatment regimen for pegcetacoplan based on the pharmacokinetic-pharmacodynamic data of the manufacturer. We conducted a clinical trial simulation with the approved dosing regimen of 1080 mg twice-weekly and a target concentration intervention-based dosing regimen in patients with and without prior eculizumab use. For eculizumab-naïve patients, the target concentration intervention-based dosing regimen resulted in a comparable fraction of patients with LDH normalization (LDH < 226 U/L) and hemoglobulin normalization (> 12 g/dL) compared to the approved regimen (LDH 50.2% and 50.0% respectively and hemoglobulin 45.6% and 44.4%). A modest dose reduction of ~ 5% was possible with target concentration intervention-based dosing. An intensified dosing interval was necessary in 2.3% of the patients however an interval prolongation was possible in 28.2% of the patients. Similar results were obtained for patients prior treated with eculizumab. In this study we show the potential of an individualized dosing regimen of pegcetacoplan with can improve patient friendliness in approximately 30% of the patients and improve therapy in approximately 2% of the patients at slightly reduced costs.

Effectiveness of omalizumab across different dosing regimens in patients with moderate-to-severe allergic asthma

For patients with moderate-to-severe persistent allergic asthma, omalizumab is approved for subcutaneous administration according to a recommended dosing table based on weight and total immunoglobulin E (IgE) level. The aim of this analysis was to assess asthma outcomes including quality of life in patients with allergic asthma initiated on omalizumab in the PROSPERO trial; patients were stratified by where their IgE and body weight fell on the approved dosing table. Patient groups were defined as Inside Dosing Table: patients whose IgE and weight fell within the approved dosing table (n = 506); Insufficient Data to Recommend a Dose: patients who fell into the section of the approved dosing table where not enough clinical data were available to make dosing recommendations (n = 72); and Outside Dosing Table: patients who fell outside the approved dosing table due to baseline IgE and/or weight (n = 209). Overall, asthma and quality of life outcomes were improved after omalizumab initiation for both patients who fall within the recommended dosing table or those who fall outside the recommended dosing table. Our results suggest that omalizumab treatment may be effective in a wide range of patients with moderate-to-severe allergic asthma.ClinicalTrials.gov identifier NCT01922037.

Abstract 16208: Population Pharmacokinetics of Intravenously and Orally Administered Sotalol in Patients With Cardiac Arrhythmias

Introduction: Recently, an intravenous (IV) formulation of sotalol was approved to provide a loading dose before initiating oral sotalol therapy to reduce hospitalization days. However, the population pharmacokinetics (PK) of sotalol after administration of an IV loading dose regimen in patients with atrial fibrillation were not characterized. Understanding the PK of IV sotalol loading dose in patients with atrial fibrillation is required to ensure safety and optimal therapeutic outcomes. Hypothesis: The population PK model of IV and orally administered sotalol can be developed using data from two clinical PK studies with reasonable empirical Bayes estimates (EBEs) of PK parameters absorption rate constant (Ka), clearance (CL), and volume of distribution (Vd). Methods: The PK dataset of sotalol was from: 1) Relative bioavailability study with IV and oral sotalol PK data by sponsor AltaThera Inc., 2) Prospective Evaluation Analysis and Kinetics of IV Sotalol (PEAKS) registry study. Population PK was evaluated using NONMEM® 7.5, Perl-speaks-NONMEM (PsN®) version 5.3.0. Results: 545 sotalol concentrations in 25 patients were analyzed. A one-compartment model with a first-order elimination rate best described the data (Figure 1). The data correlated QTc interval levels within the observed sotalol concentration range (1.2 to 1900 ng/mL) were below 500 ms. In the final model, the EBE’s of sotalol PK parameters were, Ka - 1.44 hr -1 , CL 0.46 - L/h/kg, and the Vd -5.6 L/kg. Further PK/PD studies are needed to establish the correlation between sotalol PK and safety in this population. Conclusions: The PK of sotalol after IV and oral doses were adequately described using a population PK modeling approach. The QTc levels correlated to the plasma concentrations in this study were within the safety limit of 500 ms. This population PK model could be used to correlate the PK with safety (QTc interval prolongation) further to optimize the sotalol IV and oral dosing regimen.

Phase I/II Study of Reduced Dosing of Post-Transplantation Cyclophosphamide (PTCy) after HLA-Identical Peripheral Blood Hematopoietic Stem Cell Transplantation

Introduction Post-transplant cyclophosphamide (PTCy)-based prophylaxis for acute graft versus host disease (aGvHD) has become a standard protocol in HLA haploidentical bone marrow transplantation. Preliminary evidence indicates that compared to the standard dosage (50 mg/kg on days +3 and +4 post-transplantation), a regimen of half the typical cyclophosphamide dosage is both feasible and effective. However, the optimal dosage and timing of PTCy for aGvHD prophylaxis in a HLA identical setting, using peripheral stem cells as the graft, remain unknown. This study aims to investigate the efficacy and safety of a reduced PTCy dosage regimen in patients undergoing peripheral blood stem cell transplants (PBSCT) with HLA indentical donors. Methods This prospective, single-center phase I/II study enrolled patients scheduled for PBSCT with HLA identical donors. The aGVHD prophylaxis regimen comprised PTCy on days +3 and +4, followed by cyclosporine initiation from day 5 post-transplant. In the phase I stage, an initial cohort of five patients received PTCy at a dosage of 50 mg/kg/day on days +3 and +4 (designated as dose level 1, DL1). This was followed by a 3+3 dose de-escalation design with subsequent dose levels as follows: DL2, 50 mg/kg on day +3 and 25 mg/kg on day +4; and DL3, 25 mg/kg on both day +3 and +4. The dose-limiting toxicity for this de-escalation was defined as the occurrence of grade III-IV aGVHD within the first 100 days post-transplantation. The phase II stage comprised an expansion cohort, which was based on the optimal dose identified during phase I. aGvHD classification was established using the Mount Sinai Acute GVHD International Consortium (MAGIC) criteria, while chronic GvHD (cGvHD) was assessed per the latest National Institutes of Health Consensus on cGvHD. Patients were closely followed-up at +1, +2, +3, +4, +6, +9, +12, +18, and +24 months post-transplant. Results In the first stage, a total of 11 patients (5 in DL1, 3 in DL2, and 3 in DL3) were included, and no patient developed grade III-IV aGVHD. Based on this, DL3 was selected as the PTCy dose for phase II, which comprised 18 patients. Overall, 29 patients (17 females, 12 males) with a median age of 39 years (range 17-65) were included, and the median follow-up duration was 12.7 months (range 2.2-22.1). Patient and disease characteristics are summarized in Table 1. By day +30 post-ASCT, all patients achieved complete remission (CR) and minimal residual disease (MRD) clearance. No patient developed grade III-IV aGVHD within 100 days post-transplantation. There was no significant difference in the neutrophil and platelet engraftment interval among the three groups (Figure 1A, B). Among the 21 patients who received the DL3 dose of PTCy, the estimated cumulative incidence of grade II to IV aGVHD at day +100 was recorded at 28.6%, and the incidence of aGVHD at day +100 presented no difference among the three DL groups (Figure 1C). In addition, 1 patient in DL3 developed grade IV intestinal aGVHD on day +141 and died one month later. The estimated 1-year cumulative incidence of hemorrhagic cystitis (HC) and cytomegalovirus (CMV) reactivation was 19.3% and 19%, respectively (Figure 1D). Five patients (all in DL3) experienced relapse, with a median interval of 6.7 months and an estimated 1-year cumulative incidence of 10.6%. A total of 5 fatalities occurred during our study (1 in DL1, and 4 in DL3), 1 due to relapse, 2 from COVID-19-associated pulmonary aspergillosis, 1 from severe septicemia and 1 due to grade IV aGVHD as mentioned above. The estimated 6-month cumulative incidence of NRM was 9.5%, presenting no difference among the three DL groups (Figure 1E). Among the 20 evaluable patients, the estimated 1-year cumulative incidence of chronic GVHD (cGVHD) and moderate cGVHD was 37.3% and 16% (Figure 1F), respectively, with no severe cGVHD observed. No cases of patient relapse were reported. The estimated 1-year progression-free survival (PFS) and overall survival (OS) were 61.2% and 80.4%, respectively (Figure 1G). Conclusion The findings of this study substantiate that a two-day regimen of PTCy at 25 mg/kg/day serves as an effective and safe prophylactic measure against aGVHD, comparable to the standard dosing protocol. However, to definitively establish whether the de-escalated PTCy dosage provides superior outcomes to the standard regimen, longer-term follow-up and comparative studies are warranted.

Central Nervous System Distribution of Panobinostat in Preclinical Models to Guide Dosing for Pediatric Brain Tumors.

Achieving adequate exposure of the free therapeutic agent at the target is a critical determinant of efficacious chemotherapy. With this in mind, a major challenge in developing therapies for central nervous system (CNS) tumors is to overcome barriers to delivery, including the blood-brain barrier (BBB). Panobinostat is a nonselective pan-histone deacetylase inhibitor that is being tested in preclinical and clinical studies, including for the treatment of pediatric medulloblastoma, which has a propensity for leptomeningeal spread and diffuse midline glioma, which can infiltrate into supratentorial brain regions. In this study, we examined the rate, extent, and spatial heterogeneity of panobinostat CNS distribution in mice. Transporter-deficient mouse studies show that panobinostat is a dual substrate of P-glycoprotein (P-gp) and breast cancer resistant protein (Bcrp), which are major efflux transporters expressed at the BBB. The CNS delivery of panobinostat was moderately limited by P-gp and Bcrp, and the unbound tissue-to-plasma partition coefficient of panobinostat was 0.32 and 0.21 in the brain and spinal cord in wild-type mice. In addition, following intravenous administration, panobinostat demonstrated heterogeneous distribution among brain regions, indicating that its efficacy would be influenced by tumor location or the presence and extent of leptomeningeal spread. Simulation using a compartmental BBB model suggests inadequate exposure of free panobinostat in the brain following a recommended oral dosing regimen in patients. Therefore, alternative approaches to CNS delivery may be necessary to have adequate exposure of free panobinostat for the treatment of a broad range of pediatric brain tumors. SIGNIFICANCE STATEMENT: This study shows that the central nervous system (CNS) penetration of panobinostat is limited by P-gp and Bcrp, and its efficacy may be limited by inadequate distribution to the tumor. Panobinostat has heterogeneous distribution into various brain regions, indicating that its efficacy might depend on the anatomical location of the tumors. These distributional parameters in the mouse CNS can inform both preclinical and clinical trial study design and may guide treatment for these devastating brain tumors in children.

Optimization of secukinumab dose regimens in patients with moderate-to-severe plaque psoriasis via exposure-response modeling

ABSTRACT Background Further dose optimization is required for patients with moderate-to-severe plaque psoriasis who do not benefit from the approved secukinumab dose regimen. This study aimed to develop an exposure-response model for secukinumab to recommend dose regimens for patients of different body weights. Methods We searched the PubMed and Cochrane Library databases for randomized controlled trials using PASI 75 and PASI 90 response rates as primary outcomes. A model-based meta-analysis was developed to quantitatively analyze the distribution of six secukinumab dose regimens in patients weighing 50–120 kg. Results Sixteen trials involving 6,197 subjects were included in the analysis. The established model accurately described the time-course characteristics of PASI 75 and PASI 90 response rates over 52 weeks. Simulations indicated that maintenance doses could be reduced to 150 mg every 4 weeks and to 150 mg every 3 weeks for patients weighing 50 and 60 kg, respectively. In contrast, maintenance doses of 300 mg every 3 weeks should be selected for patients weighing 120 kg. Patients weighing 70–110 kg remained on approved maintenance doses of 300 mg every 4 weeks. Conclusions Based on patient body weights, the exposure-response model recommends efficacious and economical dose regimens for patients with moderate-to-severe plaque psoriasis.

Quantitative Assessment of Ribociclib Exposure-Response Relationship to Justify Dose Regimen in Patients with Advanced Breast Cancer.

Ribociclib in combination with endocrine therapy (ET) is a globally approved treatment option for patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor2-negative (HER2-) advanced breast cancer (ABC) and has demonstrated significantly improved overall survival (OS) in 3 phase3 clinical trials. To justify the dose regimen and dose modification scheme for patients with ABC, the pharmacokinetic (PK), safety, and efficacy data of ribociclib were analyzed. The data of several phase1-3 clinical studies were pooled and analyzed to characterize the relationship between exposure (dose or PK) and efficacy (progression-free survival (PFS), time to response, and OS) or safety (neutropenia and QT interval prolongation). The exposure-efficacy analysis showed no apparent relationship between ribociclib exposure and efficacy (PFS and OS), and efficacy analysis by dose reduction showed that patients with ABC continued to benefit from the treatment following dose reduction, supporting the starting dose of 600mg as well as dose reductions to 400 and 200mg. The exposure-safety analysis showed that neutropenia and QT prolongation are related to ribociclib exposure that can be effectively managed by individualized dose modification (dose reduction/interruption). Collective evidence from the exposure-response analyses for efficacy and safety support the use of ribociclib in combination with ET partners at the starting dose of 600mg, and also the effectiveness of individualized dose reductions in managing safety, while maintaining efficacy, in patients with HR+/HER2- ABC. This analysis illustrates the utility of quantitative assessment in justifying dose selection and dose modification for oncology medicines.

Anti-inflammatory effects of dexamethasone in COVID-19 patients: Translational population PK/PD modeling and simulation.

Dexamethasone (DEX) given at a dose of 6 mg once-daily for 10 days is a recommended dosing regimen in patients with coronavirus disease 2019 (COVID-19) requiring oxygen therapy. We developed a population pharmacokinetic and pharmacodynamic (PopPK/PD) model of DEX anti-inflammatory effects in COVID-19 and provide simulations comparing the expected efficacy of four dosing regimens of DEX. Nonlinear mixed-effects modeling and simulations were performed using Monolix Suite version 2021R1 (Lixoft, France). Published data for DEX PK in patients with COVID-19 exhibited moderate variability with a clearance of about half that in healthy adults. No accumulation of the drug was expected even with daily oral doses of 12 mg. Indirect effect models of DEX inhibition of TNFα, IL-6, and CRP plasma concentrations were enacted and simulations performed for DEX given at 1.5, 3, 6, and 12 mg daily for 10 days. The numbers of individuals that achieved specified reductions in inflammatory biomarkers were compared among the treatment groups. The simulations indicate the need for 6 or 12 mg daily doses of DEX for 10 days for simultaneous reductions in TNFα, IL-6, and CRP. Possibly beneficial is DEX given at a dose of 12 mg compared to 6 mg. The PopPK/PD model may be useful in the assessment of other anti-inflammatory compounds as well as drug combinations in the treatment of cytokine storms.

Therapeutic potential of sodium selenite in patients with non-alcoholic fatty liver disease and hypertension disease

Liver parenchyma damage is associated with significant activation of oxidative stress. Correction of oxidative stress can be a promising direction in the treatment of arterial hypertension. It has been established that in patients with hepatopathies, lower concentrations of selenium are found in blood and erythrocytes, which gives reason to consider selenium as a potential therapeutic agent in patients with liver pathology.&#x0D; Objective — to determine the therapeutic potential of sodium selenite in patients with non‑alcoholic fatty liver disease in combination with hypertension.&#x0D; Materials and methods. 100 patients with nonalcoholic fatty liver disease (NAFLD) were included in the study: the main group — 49 patients (67.3% women, median age is 51.0 years) with concomitant NAFLD and arterial hypertension (HTN), the comparison group — 51 patients (58.8% women, median age is 52.0 years) with NAFLD isolated course. The control group included 20 practically healthy people (55.0% women, median age is 51.0 years). Among the patients of the main group, the first degree of HTN was diagnosed in 28.6% of patients (14 people), the second degree — 71.4% (35 people). Among these patients, 32.7% (16 people) had the first stage of HTN, 67.3% (33 people) had the second stage. In the main group, 55.1% of patients had steatosis, 44.9% had steatohepatitis. In the comparison group, 58.8% had steatosis, 41.2% had steatohepatitis (χ2=0.141, p=0.707). The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured according to the standard method (kinetic method). Gamma‑glutamine transpeptidase (GGTP) was measured by the enzymatic colorimetric method, alkaline phosphatase (AP) by the colorimetric method. Selenium and selenoprotein P (Sel P) levels were determined using the immunofluorescence method. Ultrasound examination of the liver was performed according to the standard method on an empty stomach.&#x0D; Results. Body mass index corresponded to normal or increased body weight: in the main group — 27.8 [26.6; 28.5] kg/ m2 and 27.3 [24.2; 28.3] kg/ m2 in the comparison group, in the control group — 24.3 [21.9; 26.0] kg/ m2. In patients of the main group was determined a significant (p &lt;0.001) predominance of ALT levels (45 [43.0; 47.5] U/ L), AST levels (53 [51.0; 56.0] U/ L), AP levels (285.7 [217.6; 321.1] U/ L) and GGTP levels (96.2 [75.0; 108.9] U/ L) opposite to comparison group (respectively 36 [34.0; 39.0] U/ L, 41 [40.0; 45.0] U/ L, 215.5 [183.2; 246.7] U/ L and 65.5 [51.5; 76.8] U/ L) and control group levels (respectively 25.5 [24.0; 30.8] U/ L, 23 [19.3; 26.0] U/ L, 129.2 [116.9; 140.6] U/ L and 22.6 [16.1; 31.7] U/ L). A two‑fold decrease in selenoprotein P levels was obtained in patients with NAFLD and HTN compared to patients with NAFLD (19.7 [8.0; 26.7] ng/ mL and 43.1 [41.3; 45.4] ng/ mL respectively, p &lt;0.001), and selenium in one and a half times compared to patients with NAFLD (43.5 [39.9; 49.1] g/ L and 67.2 [61.5; 77.4] g/ L respectively, p &lt;0.001). The highest Sel P median levels (71.0 [54.3; 76.1] ng/ ml and selenium levels (108.0 [96.9; 118.8] g/ L) registered in the control group (p &lt;0.001). Evaluating the data on selenium metabolism and liver tests depending on the intake of sodium selenite, a significant increase in the levels of Sel P (53.6 [43.1; 60.4] ng/ ml, p &lt;0.001) and selenium (89.1 [63, 4; 99.5] g/ L, p &lt;0.009), as well as a decrease in AST levels (41.7 [32.6; 43.2] U/ l, p &lt;0.001) in the group with isolated NAFLD, while in the group with NAFLD and HTN comorbid course, no significant changes in the studied parameters were detected.&#x0D; Conclusions. The obtained results provide a basis for sodium selenite use in the therapy of patients with NAFLD. Further research on the duration of such therapy and sodium selenite dosing regimen in patients with a comorbid course of NAFLD and HTN is a promising and relevant direction.&#x0D;

Population Pharmacokinetics and Exposure-Response Analysis of Tremelimumab 300mg Single Dose Combined with Durvalumab 1500mg Q4W (STRIDE) in Patients with Unresectable Hepatocellular Carcinoma.

A novel single-dose regimen of 300mg tremelimumab in combination with durvalumab (STRIDE) has demonstrated a favorable benefit-risk profile in the phase1/2 Study22 trial (in patients with unresectable hepatocellular carcinoma, uHCC) and in the phase3 HIMALAYA study. The current analysis evaluated the population pharmacokinetics (PopPK) of tremelimumab and durvalumab, and the exposure-response (ER) relationship for efficacy and safety of STRIDE in patients with uHCC. Previous PopPK models for tremelimumab and durvalumab were updated using data from previous studies in various cancers combined with data from Study22 and HIMALAYA. Typical population mean parameters and associated inter- and intra-individual variability were assessed, as was the influence of covariates. Individual exposure metrics were derived from the individual empirical Bayes estimates as drivers for ER analysis related to efficacy and safety from HIMALAYA. The observed pharmacokinetics of tremelimumab in uHCC were well described by a 2-compartment model with both linear and time-dependent clearance. All identified covariates changed tremelimumab PK parameters by <25%, and thus had minimal clinical relevance; similar results were obtained from durvalumab PopPK analysis. None of tremelimumab or durvalumab exposure metrics were significantly associated with overall survival (OS), progression-free survival (PFS), or adverse events. Baseline aspartate aminotransferase and neutrophil-to-lymphocyte ratio (NLR) were associated with OS (P<.001) by the Cox proportional hazards model. No covariate was identified as a significant factor for PFS. No dose adjustment for tremelimumab or durvalumab is needed based on PopPK covariate analyses or ER analyses. Our findings support the novel STRIDE dosing regimen in patients with uHCC.