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Background: Caspofungin is an echinocandin antifungal agent commonly used as the first-line therapy for invasive candidiasis, salvage therapy for invasive aspergillosis, and empirical therapy for presumed fungal infections. Pharmacokinetic (PK) variabilities and suboptimal exposure have been reported for caspofungin, increasing the risk of insufficient efficacy. Objective: This work aimed to develop a caspofungin population pharmacokinetic (popPK) library and demonstrate its utility by assessing the probability of target attainment across diverse settings. Methods: We established a caspofungin popPK model library following a rigorous literature review, re-implementing selected models in R with rxode2. Quality control procedures included a comparison of different studies and assessing covariate impacts. Model libraries were primarily used to perform Monte Carlo simulations to estimate target attainment and guide personalized dosing in Candida infections. Results: A total of 13 models, one- or two-compartment models, were included. The most significant covariates were body size (weight and body surface area), liver function, and albumin level. The results show that children and adults showed considerable differences in pharmacokinetics. For C. albicans and C. parapsilosis, none of the populations achieved a PTA of ≥90% at their respective susceptible MIC values. In contrast, for C. glabrata, 70% of the adult studies reached a PTA of ≥90%, while all pediatric studies achieved the same PTA level. Conclusion: At the recommended dosage, adult patients showed notably lower exposure to caspofungin compared to pediatric patients. Considering body size, liver function, and serum albumin is crucial when determining caspofungin dosage regimens. Furthermore, further research is required to comprehensively understand the pharmacokinetics of caspofungin in pediatric patients. [ABSTRACT FROM AUTHOR]

• High-dose individualized ATG with TDM is safe. • Actual exposures of ATG can be well predicted. • The protocol is effective to prevent GvHD and rejection in this high-risk population. Graft-versus-host disease (GvHD) and rejection are main limitations of cord blood transplantation (CBT), more so in patients with severe inflammation or previous rejections. While rigorous T-cell depletion with antithymocyte globulin (ATG) is needed to prevent GvHD and rejection, overexposure to ATG leads to slow T-cell recovery after transplantation, especially in CBT. To evaluate high-dose, upfront ATG with individualized dosing and therapeutic drug monitoring (TDM) in pediatric CBT for patients at high risk for GvHD and rejection. Heavily inflamed patients and patients with a recent history of rejection were eligible for individualized high-dose ATG with real-time TDM. The ATG dosing scheme was adjusted to target a post-CBT exposure of <10 AU*day/mL, while achieving a pre-CBT exposure of 60–120 AU*day/mL; exposure levels previously defined for optimal efficacy and safety in terms of reduced GvHD and rejection, respectively. Main outcomes of interest included efficacy (target exposure attainment) and safety (incidence of GvHD and rejection). Other outcomes of interest included T-cell recovery and survival. Twenty-one patients were included ranging from 2 months to 18 years old, receiving an actual median cumulative dose of ATG of 13.3 mg/kg (range 6–30 mg/kg) starting at a median 15 days (range 12–17) prior to CBT. Dosing was adjusted in 14 patients (increased in 3 and decreased in 11 patients). Eighteen (86%) and 19 (91%) patients reached the target pre-CBT and post-CBT exposure, respectively. Cumulative incidence for acute GvHD was 34% (95% CI 23–45) and 5% (95% CI 0–10%) for grade 2–4 and grade 3–4, respectively; cumulative incidence of rejection was 9% (95% CI 2–16%). Overall survival was 75% (95% CI 65–85%). Individualized high-dose ATG with TDM is feasible and safe for patients with hyperinflammation in a CBT setting. We observe high target ATG exposure attainment, good immune reconstitution (despite very high doses of ATG) and acceptable rates of GvHD and rejection. [ABSTRACT FROM AUTHOR]

Rationale: Understanding mechanisms of drug use decisions will inform the development of treatments for opioid use disorder (OUD). Decision-making experiments using neurobehavioral approaches require many trials or events of interest for statistical analysis, but the pharmacokinetics of most opioids limit dosing in humans. Objectives: This experiment characterized the effects of repeated infusions of the ultra-short acting opioid remifentanil in people with OUD and physical opioid dependence. Methods: An inpatient study using a within-subjects, single-blind, escalating, within-session, pre-post design was conducted. Seven (3 female) subjects were maintained on oral oxycodone (40–60 mg, 4x/day = 160–240 total mg/day) for seven days prior to the dose-ranging session. Subjects received infusions of three ascending remifentanil doses (0.03, 0.1, 0.3 mcg/kg/infusion in 2 subjects; 0.1, 0.3, 1.0 mcg/kg/infusion in 5 subjects) every minute for 40 min per dose, with infusions administered over 5 s to model naturalistic delivery rates. End tidal carbon dioxide, respiration rate, oxygen saturation (SpO2) and heart rate were measured continuously. Blood pressure (BP), pupil diameter and self-reported drug effects were measured every 5 min. Results: Pupil diameter, SpO2 and systolic BP decreased, and ratings on prototypic subjective effects questionnaire items increased, as a function of remifentanil dose. The number of infusions held because of sedation or physiological parameters exceeding predetermined cutoffs also increased with dose. Conclusions: This experiment established doses and procedures for the safe delivery of rapid, repeated remifentanil infusions to individuals with OUD and physical fentanyl dependence, which can be applied to the mechanistic study of opioid use decisions. [ABSTRACT FROM AUTHOR]

Traditional weight-based dosing of rabbit anti-thymocyte globulin (rATG) used in allogeneic hematopoietic cell transplantation (HCT) to prevent graft-versus-host disease (GVHD) and graft rejection leads to variable exposures. High exposures induce delayed CD4+immune reconstitution (CD4+IR) and greater mortality. We sought to determine the impact of rATG exposure in children and young adults receiving various types of EX-VIVO T-cell–depleted (EX-VIVO-TCD) HCT. Patients receiving their first EX-VIVO-TCD HCT (CliniMACS CD34+, Isolex or soybean lectin agglutination), with removal of residual T cells by E-rosette depletion (E-) between 2008 and 2018 at Memorial Sloan Kettering Cancer Center were retrospectively analyzed. rATG exposure post-HCT was estimated (AU*d/L) using a validated population pharmacokinetic model. Previously defined rATG-exposures, <30, 30–55, ≥55 AU*d/L, were related with outcomes of interest. Cox proportional hazard and cause-specific models were used for analyses. In total, 180 patients (median age 11 years; range 0.1–44 years) were included, malignant 124 (69%) and nonmalignant 56 (31%). Median post-HCT rATG exposure was 32 (0–104) AU*d/L. Exposure <30 AU*d/L was associated with a 3-fold greater probability of CD4+IR (P < 0.001); 2- to 4-fold lower risk of death (P = 0.002); and 3- to 4-fold lower risk of non-relapse mortality (NRM) (P = 0.02). Cumulative incidence of NRM was 8-fold lower in patients who attained CD4+IR compared with those who did not (P < 0.0001). There was no relation between rATG exposure and aGVHD (P = 0.33) or relapse (P = 0.23). Effect of rATG exposure on outcomes was similar in three EX-VIVO-TCD methods. Individualizing rATG dosing to target a low rATG exposure post-HCT while maintaining total cumulative exposure may better predict CD4+IR, reduce NRM and increase overall survival, independent of the EX-VIVO-TCD method. [ABSTRACT FROM AUTHOR]

Mavacamten is the first and only cardiac myosin inhibitor approved in 5 continents for the treatment of adults with symptomatic New York Heart Association class II and III obstructive hypertrophic cardiomyopathy. An evidence‐based rationale was used to develop individualized mavacamten dosing, guided by commonly used clinical parameters. Echocardiography is recommended as part of routine clinical assessment of patients with hypertrophic cardiomyopathy, and left ventricular (LV) outflow tract gradient and LV ejection fraction are parameters that can be readily assessed and monitored by echocardiography. Therefore, an echocardiography‐based, clinically guided dose‐titration strategy was developed to optimize patient benefit from mavacamten for the treatment of symptomatic obstructive hypertrophic cardiomyopathy while minimizing the risk of LV ejection fraction reduction. Results from clinical trials paired with extensive modeling and simulation analyses support a dose‐titration and monitoring strategy based on serial echocardiographic measures of Valsalva LV outflow tract gradient and LV ejection fraction. This dosing approach allows for the identification of the lowest individualized mavacamten dose and exposure required to provide improvements in LV outflow tract obstruction, functional capacity, and symptoms. Mavacamten is primarily metabolized by CYP2C19 (cytochrome P450 2C19), and CYP2C19 metabolizer phenotype has an effect on mavacamten exposure. Therefore, this approach has also been demonstrated to provide a favorable safety profile irrespective of patients' CYP2C19 metabolizer status. The dose‐titration strategy includes additional considerations for the potential onset of systolic dysfunction in the context of intercurrent illness, and for the potential of drug–drug interactions with inhibitors and substrates of cytochrome P450 enzymes. This posology is reflected in the mavacamten US prescribing information.

Background: Due to the heterogeneity of critically ill patients, the pharmacokinetics of tigecycline are unclear, and the optimal dosing strategy is controversial. Methods: A single-center prospective clinical study that included critically ill patients who received tigecycline was performed. Blood samples were intensively sampled (eight samples each), and plasma drug concentrations were determined. A population pharmacokinetic (PPK) model was developed and evaluated by goodness-of-fit plots, bootstrap analysis and visual predictive checks. Monte Carlo simulation was conducted to optimize the dosage regimen. Results: Overall, 751 observations from 98 patients were included. The final PPK model was a two-compartment model incorporating covariates of creatinine clearance on clearance (CL), body weight on both central and peripheral volumes of distribution (V1 and V2), γ-glutamyl transferase and total bilirubin on intercompartment clearance (Q), and albumin on V2. The typical values of CL, Q, V1 and V2 were 3.09 L/h, 39.7 L/h, 32.1 L and 113 L, respectively. A dosage regimen of 50 mg/12 h was suitable for complicated intra-abdominal infections, but 100 mg/12 h was needed for community-acquired pneumonia, skin and skin structure infections and infections caused by less-susceptive bacteria. Conclusion: The Tigecycline PPK model was successfully developed and validated. Individualized dosing of tigecycline could be beneficial for critically ill patients. [ABSTRACT FROM AUTHOR]

Topical drug delivery is widely used in various diseases because of the advantages of not passing through the gastrointestinal tract, avoiding gastrointestinal irritation and hepatic first-pass effect, and reaching the lesion directly to reduce unnecessary adverse reactions. The skin helps the organism to defend itself against a huge majority of external aggressions and is one of the most important lines of defense of the body. However, the skin's strong barrier ability is also a huge obstacle to the effectiveness of topical medications. Allowing the bioactive, composition in a drug to pass through the stratum corneum barrier as needed to reach the target site is the most essential need for the bioactive, composition to exert its therapeutic effect. The state of the skin barrier, the choice of delivery system for the bioactive, composition, and individualized disease detection and dosing planning influence the effectiveness of topical medications. Nowadays, enhancing transdermal absorption of topically applied drugs is the hottest research area. However, enhancing transdermal absorption of drugs is not the first choice to improve the effectiveness of all drugs. Excessive transdermal absorption enhances topical drug accumulation at non-target sites and the occurrence of adverse reactions. This paper introduces topical drug delivery strategies to improve drug effectiveness from three perspectives: skin barrier, drug delivery system and individualized drug delivery, describes the current status and shortcomings of topical drug research, and provides new directions and ideas for topical drug research. [ABSTRACT FROM AUTHOR]

Abstract Purpose To explore the efficacy and safety of individualized follitropin delta dosing, based on serum anti-Müllerian hormone (AMH) concentration and bodyweight, in a long gonadotropin-releasing hormone (GnRH) agonist protocol. Methods Clinical outcomes after one treatment cycle are reported in women with AMH: 5–35 pmol/L. Oocytes were inseminated by intracytoplasmic sperm injection, blastocyst transfer was on Day 5 and remaining blastocysts were cryopreserved. Data collection included live births and neonatal health follow-up for all fresh/frozen transfers performed within one year after treatment allocation. Results In total, 104 women started stimulation, of whom 101 had oocyte recovery and 92 had blastocyst transfer. The average daily dose of follitropin delta was 11.0 ± 1.6 µg and the duration of stimulation was 10.3 ± 1.6 days. The mean number of oocytes was 12.5 ± 6.4, the mean number of blastocysts was 5.1 ± 3.4, and 85% had at least one good-quality blastocyst. Following mostly single blastocyst transfer (95%), the ongoing pregnancy rate was 43%, the live-birth rate was 43%, and the cumulative live-birth rate was 58% per started stimulation. There were 6 cases of early OHSS (5.8%) graded as mild (n = 3) and moderate (n = 3) and 6 cases of late OHSS (5.8%) graded as moderate (n = 3) and severe (n = 3). Conclusion In this first evaluation of the individualized follitropin delta dosing in a long GnRH agonist protocol, the cumulative live-birth rate was high. A randomized trial comparing follitropin delta in a long GnRH agonist protocol versus in a GnRH antagonist protocol should provide further insight into the efficacy and safety of this treatment option. Trial registration number NCT03564509; June 21, 2018.

Background: Caspofungin is an echinocandin antifungal agent commonly used as the first-line therapy for invasive candidiasis, salvage therapy for invasive aspergillosis, and empirical therapy for presumed fungal infections. Pharmacokinetic (PK) variabilities and suboptimal exposure have been reported for caspofungin, increasing the risk of insufficient efficacy. Objective: This work aimed to develop a caspofungin population pharmacokinetic (popPK) library and demonstrate its utility by assessing the probability of target attainment across diverse settings. Methods: We established a caspofungin popPK model library following a rigorous literature review, re-implementing selected models in R with rxode2. Quality control procedures included a comparison of different studies and assessing covariate impacts. Model libraries were primarily used to perform Monte Carlo simulations to estimate target attainment and guide personalized dosing in Candida infections. Results: A total of 13 models, one- or two-compartment models, were included. The most significant covariates were body size (weight and body surface area), liver function, and albumin level. The results show that children and adults showed considerable differences in pharmacokinetics. For C. albicans and C. parapsilosis, none of the populations achieved a PTA of ≥90% at their respective susceptible MIC values. In contrast, for C. glabrata, 70% of the adult studies reached a PTA of ≥90%, while all pediatric studies achieved the same PTA level. Conclusion: At the recommended dosage, adult patients showed notably lower exposure to caspofungin compared to pediatric patients. Considering body size, liver function, and serum albumin is crucial when determining caspofungin dosage regimens. Furthermore, further research is required to comprehensively understand the pharmacokinetics of caspofungin in pediatric patients.

Introduction: Fine-tuning of injectable gonadotropin doses during ovulation induction (OI) or ovarian stimulation (OS) treatment cycles with the aim of using doses low enough to minimize the risk of excessive ovarian response while maintaining optimal efficacy may be facilitated by using an adjustable-dose pen injector. We examined the incidence and magnitude of individualized gonadotropin dose adjustments made during cycles of OI or OS, followed by either timed intercourse or intrauterine insemination, with or without oral medications, and assessed the relationship between patient characteristics and dosing changes using real-world evidence. Methods: This was an observational, retrospective cohort study using electronic medical records from a large US database of fertility centers. Data from patients who had undergone a first recombinant human follicle stimulating hormone alfa (r-hFSH-alfa/follitropin alfa) treated OI/OS cycle followed by timed intercourse or intrauterine insemination between 2015 and 2016 were included. Percentages of OI/OS cycles involving r-hFSH-alfa dose adjustments (in increments of ±12.5 IU or greater) with or without oral medications (clomiphene citrate or letrozole) were analyzed. Results: Of 2,832 OI/OS cycles involving r-hFSH-alfa administration, 74.6% included combination treatment with orals; 25.4% involved r-hFSH-alfa alone. As expected, the starting dose of r-hFSH-alfa was lower for cycles that used r-hFSH-alfa with orals than r-hFSH-alfa only cycles (mean [SD]: 74.2 [39.31] vs 139.3 [115.10] IU). Dose changes occurred in 13.7% of r-hFSH-alfa with orals versus 43.9% of r-hFSH-alfa only cycles. Dose adjustment magnitudes ranged from ±12.5 IU to ±450 IU. The smallest adjustment magnitudes (±12.5 IU and ±25 IU) were used frequently and more often for dose increases than for dose decreases. For r-hFSH-alfa with orals and r-hFSH-alfa only cycles, the smallest adjustments were used in 53.5% and 64.5% of cycles with dose increases and in 35.7% and 46.8% of cycles with dose decreases, respectively. Discussion: In OI/OS cycles followed by timed intercourse or intrauterine insemination, r-hFSH-alfa dose adjustments were frequent. In cycles that included orals, r-hFSH-alfa starting doses were lower and dose changes were fewer than with r-hFSH-alfa alone. Smaller dose adjustments facilitate individualized treatment with the goal of reducing the risks of multiple gestation, cycle cancellation, and ovarian hyperstimulation syndrome. [ABSTRACT FROM AUTHOR]

Background: Treatment-resistant depression (TRD) is a substantial public health burden, but current treatments have limited effectiveness. The aim was to investigate the safety and potential antidepressant effects of the serotonergic psychedelic drug 5-MeO-DMT in a vaporized formulation (GH001) in adult patients with TRD. Methods: The Phase 1 part (n = 8) of the trial investigated two single dose levels of GH001 (12 mg, 18 mg) with a primary endpoint of safety, and the Phase 2 part (n = 8) investigated an individualized dosing regimen (IDR) with up to three increasing doses of GH001 (6 mg, 12 mg, and 18 mg) within a single day, with a primary endpoint of efficacy, as assessed by the proportion of patients in remission (MADRS = 10) on day 7. Results: Administration of GH001 via inhalation was well tolerated. The proportion of patients in remission (MADRS = 10) at day 7 was 2/4 (50%) and 1/4 (25%) in the 12 mg and 18 mg groups of Phase 1, respectively, and 7/8 (87.5%) in the IDR group of Phase 2, meeting its primary endpoint (p < 0.0001). All remissions were observed from day 1, with 6/10 remissions observed from 2 h. The mean MADRS change from baseline to day 7 was -21.0 (-65%) and - 12.5 (-40%) for the 12 and 18 mg groups, respectively, and - 24.4 (-76%) for the IDR. Conclusion: Administration of GH001 to a cohort of 16 patients with TRD was well tolerated and provided potent and ultra-rapid antidepressant effects. Individualized dosing with up to three doses of GH001 on a single day was superior to single dose administration. [ABSTRACT FROM AUTHOR]

Abstract Background To compare the efficacy and safety of follitropin delta in its individualized fixed-dose regimen with follitropin alfa in a conventional adjustable dosing regimen in Chinese women. Methods This was a subgroup analysis of the randomized, multi-center, assessor-blind, non-inferiority trial (GRAPE) including 759 Chinese women (aged 20–40 years) recruited in 16 reproductive medicine clinics in China. Women were randomized in a 1:1 ratio to be treated with either follitropin delta dose based on anti-Müllerian hormone (AMH) and body weight or conventional dosing with follitropin alfa following a gonadotropin-releasing hormone (GnRH) antagonist protocol. The primary outcome was ongoing pregnancy rate assessed 10–11 weeks after embryo transfer in the fresh cycle (non-inferiority margin -10.0%). Results 378 in the follitropin delta group and 381 in the follitropin alfa group were randomized and exposed. Non-inferiority was confirmed with respect to ongoing pregnancy with rates of 31.0% vs. 25.7% for follitropin delta compared to follitropin alfa, estimated mean difference of 5.1% (95% confidence interval (CI) -1.3% to 11.5%). The clinical pregnancy rate (35.4% vs. 31.5%, P = 0.239) and live birth rate (31.0% vs. 25.5%, P = 0.101) were comparable between the follitropin delta group and the follitropin alfa group. Overall, the individualized follitropin delta treatment resulted in fewer oocytes retrieved compared to follitropin alfa treatment (10.3 ± 6.2 vs. 12.5 ± 7.5, P

Purpose: To explore the efficacy and safety of individualized follitropin delta dosing, based on serum anti-Müllerian hormone (AMH) concentration and bodyweight, in a long gonadotropin-releasing hormone (GnRH) agonist protocol. Methods: Clinical outcomes after one treatment cycle are reported in women with AMH: 5–35 pmol/L. Oocytes were inseminated by intracytoplasmic sperm injection, blastocyst transfer was on Day 5 and remaining blastocysts were cryopreserved. Data collection included live births and neonatal health follow-up for all fresh/frozen transfers performed within one year after treatment allocation. Results: In total, 104 women started stimulation, of whom 101 had oocyte recovery and 92 had blastocyst transfer. The average daily dose of follitropin delta was 11.0 ± 1.6 µg and the duration of stimulation was 10.3 ± 1.6 days. The mean number of oocytes was 12.5 ± 6.4, the mean number of blastocysts was 5.1 ± 3.4, and 85% had at least one good-quality blastocyst. Following mostly single blastocyst transfer (95%), the ongoing pregnancy rate was 43%, the live-birth rate was 43%, and the cumulative live-birth rate was 58% per started stimulation. There were 6 cases of early OHSS (5.8%) graded as mild (n = 3) and moderate (n = 3) and 6 cases of late OHSS (5.8%) graded as moderate (n = 3) and severe (n = 3). Conclusion: In this first evaluation of the individualized follitropin delta dosing in a long GnRH agonist protocol, the cumulative live-birth rate was high. A randomized trial comparing follitropin delta in a long GnRH agonist protocol versus in a GnRH antagonist protocol should provide further insight into the efficacy and safety of this treatment option. Trial registration number: NCT03564509; June 21, 2018. [ABSTRACT FROM AUTHOR]

IntroductionFine-tuning of injectable gonadotropin doses during ovulation induction (OI) or ovarian stimulation (OS) treatment cycles with the aim of using doses low enough to minimize the risk of excessive ovarian response while maintaining optimal efficacy may be facilitated by using an adjustable-dose pen injector. We examined the incidence and magnitude of individualized gonadotropin dose adjustments made during cycles of OI or OS, followed by either timed intercourse or intrauterine insemination, with or without oral medications, and assessed the relationship between patient characteristics and dosing changes using real-world evidence.MethodsThis was an observational, retrospective cohort study using electronic medical records from a large US database of fertility centers. Data from patients who had undergone a first recombinant human follicle stimulating hormone alfa (r-hFSH-alfa/follitropin alfa) treated OI/OS cycle followed by timed intercourse or intrauterine insemination between 2015 and 2016 were included. Percentages of OI/OS cycles involving r-hFSH-alfa dose adjustments (in increments of ±12.5 IU or greater) with or without oral medications (clomiphene citrate or letrozole) were analyzed.ResultsOf 2,832 OI/OS cycles involving r-hFSH-alfa administration, 74.6% included combination treatment with orals; 25.4% involved r-hFSH-alfa alone. As expected, the starting dose of r-hFSH-alfa was lower for cycles that used r-hFSH-alfa with orals than r-hFSH-alfa only cycles (mean [SD]: 74.2 [39.31] vs 139.3 [115.10] IU). Dose changes occurred in 13.7% of r-hFSH-alfa with orals versus 43.9% of r-hFSH-alfa only cycles. Dose adjustment magnitudes ranged from ±12.5 IU to ±450 IU. The smallest adjustment magnitudes (±12.5 IU and ±25 IU) were used frequently and more often for dose increases than for dose decreases. For r-hFSH-alfa with orals and r-hFSH-alfa only cycles, the smallest adjustments were used in 53.5% and 64.5% of cycles with dose increases and in 35.7% and 46.8% of cycles with dose decreases, respectively.DiscussionIn OI/OS cycles followed by timed intercourse or intrauterine insemination, r-hFSH-alfa dose adjustments were frequent. In cycles that included orals, r-hFSH-alfa starting doses were lower and dose changes were fewer than with r-hFSH-alfa alone. Smaller dose adjustments facilitate individualized treatment with the goal of reducing the risks of multiple gestation, cycle cancellation, and ovarian hyperstimulation syndrome.

BackgroundTreatment-resistant depression (TRD) is a substantial public health burden, but current treatments have limited effectiveness. The aim was to investigate the safety and potential antidepressant effects of the serotonergic psychedelic drug 5-MeO-DMT in a vaporized formulation (GH001) in adult patients with TRD.MethodsThe Phase 1 part (n = 8) of the trial investigated two single dose levels of GH001 (12 mg, 18 mg) with a primary endpoint of safety, and the Phase 2 part (n = 8) investigated an individualized dosing regimen (IDR) with up to three increasing doses of GH001 (6 mg, 12 mg, and 18 mg) within a single day, with a primary endpoint of efficacy, as assessed by the proportion of patients in remission (MADRS ≤ 10) on day 7.ResultsAdministration of GH001 via inhalation was well tolerated. The proportion of patients in remission (MADRS ≤ 10) at day 7 was 2/4 (50%) and 1/4 (25%) in the 12 mg and 18 mg groups of Phase 1, respectively, and 7/8 (87.5%) in the IDR group of Phase 2, meeting its primary endpoint (p

Study Objective: Few studies have been conducted to quantify the exposure target of vancomycin in intensive care unit (ICU) patients undergoing continuous renal replacement therapy (CRRT) and provide optimized dosage regimens. We aimed to determine vancomycin exposure target and dosing recommendations using data from an open database in critically ill patients undergoing CRRT. Design: A retrospective observational cohort study. Data Source: A large public database. Patients: The adult patients who received intravenous vancomycin and CRRT treatment in the database between 2017 and 2019 were reviewed to determine eligibility. A total of 180 patients with 1186 observations were included in the population pharmacokinetic (PPK) model development. The clinical efficacy of vancomycin was analyzed in 159 eligible patients. Methods: A PPK model was developed to estimate individual pharmacokinetic (PK) parameters. The area under the concentration‐time curve (AUC) was estimated by a Bayesian approach based on individual vancomycin concentrations. Multivariate logistic regression analyses were performed to identify the factors of clinical outcomes. Threshold of vancomycin exposure in predicting efficacy was identified via receiver operating characteristic (ROC) curve. Dosing recommendations were designed using Monte Carlo Simulations (MCS) based on the optimized exposure target. Measurements and Main Results: On covariate analysis, CRRT intensity significantly affected vancomycin PK. The AUC above 427 mg*h/L was the only significant predictor of clinical efficacy (adjusted odds ratio (aOR): 1.008, 95% confidence interval (CI): 1.004–1.011, p = 0.000). MCS indicated that vancomycin dosage regimens of 5 mg/kg q12h or 7.5 mg/kg q12h were recommended for patients with CRRT intensities of 20–25 mL/kg/h or 25.1–45 mL/kg/h, respectively. Conclusions: An AUC threshold of 427 mg*h/L (assuming the minimal inhibitory concentration (MIC) = 1 mg/L) was a recommended efficacy exposure target of vancomycin for critically ill patients undergoing CRRT. Vancomycin 5–7.5 mg/kg q12h is recommended as the initial dosage regimens for ICU patients undergoing CRRT. [ABSTRACT FROM AUTHOR]

Individualization of patient drug dosing to maximize efficacy and minimize toxicity is the goal of clinical pharmacology. Here we review the history of drug dosing individualization from early predictions for renally eliminated drugs based on kidney function through the introduction of clearance concepts for metabolic processes, the differentiation of volume of distribution between pharmacokinetics and chemistry, the role of transporters, the unique pharmacokinetic aspects of oral dosing, and the relevance of protein binding to the emergence of pharmacogenomics. The Food and Drug Administration listing of pharmacogenomic markers in approved drug labeling is analyzed with respect to the promise of genomics in terms of picking the right drug for the patient based on genetic information vs selecting or adjusting the dosage regimen based on genetic information: the former resulting in a great advance, whereas the latter has shown less convincing evidence of clinical relevance. Finally, new information on individualized predictive methodologies based on marker drugs for enzymes and transporters is reviewed. We conclude that although individualization of drug dosing will work for most drugs primarily excreted unchanged in the urine, individualization of dosing regimens is not critical for wide-therapeutic-index drugs, whereas for narrow-therapeutic-index drugs predictions are most often more hype than reality, with therapeutic drug monitoring required. However, continuing advances in discovering and validating biomarkers will lead to predictions of pharmacokinetics/pharmacodynamics in the individualized patient that should result in shifting the hype to reality with time.

Purpose: Although metastatic breast cancer (MBC) is treatable, it is not curable and most patients remain on treatment indefinitely. While oncologists commonly prescribe the recommended starting dose (RSD) from the FDA-approved label, patient tolerance may differ from that seen in clinical trials. We report on a survey of medical oncologists' perspectives about treatment-related toxicity and willingness to discuss flexible dosing with patients. Methods: We disseminated a confidential survey via social media/email in Spring 2021. Eligible respondents needed to be US-based medical oncologists with experience treating patients with MBC. Results: Of 131 responses, 119 were eligible. Physicians estimated that 47% of their patients reported distressing treatment-related side effects; of these, 15% visited the Emergency Room/hospital and 37% missed treatment. 74% (n = 87) of doctors reported improvement of patient symptoms after dose reduction. 87% (n = 104) indicated that they had ever, if appropriate, initiated treatment at lower doses. Most (85%, n = 101) respondents did not believe that the RSD is always more effective than a lower dose and 97% (n = 115) were willing to discuss individualized dosing with patients. Conclusion: Treatment-related side effects are prevalent among patients with MBC, resulting in missed treatments and acute care visits. To help patients tolerate treatment, oncologists may decrease initial and/or subsequent doses. The majority of oncologists reject the premise that a higher dose is always superior and are willing to discuss individualized dosing with patients. Given potential improvements regarding quality of life and clinical care, dose modifications should be part of routine shared decision-making between patients and oncologists. [ABSTRACT FROM AUTHOR]

Background: To compare the efficacy and safety of follitropin delta in its individualized fixed-dose regimen with follitropin alfa in a conventional adjustable dosing regimen in Chinese women. Methods: This was a subgroup analysis of the randomized, multi-center, assessor-blind, non-inferiority trial (GRAPE) including 759 Chinese women (aged 20–40 years) recruited in 16 reproductive medicine clinics in China. Women were randomized in a 1:1 ratio to be treated with either follitropin delta dose based on anti-Müllerian hormone (AMH) and body weight or conventional dosing with follitropin alfa following a gonadotropin-releasing hormone (GnRH) antagonist protocol. The primary outcome was ongoing pregnancy rate assessed 10–11 weeks after embryo transfer in the fresh cycle (non-inferiority margin -10.0%). Results: 378 in the follitropin delta group and 381 in the follitropin alfa group were randomized and exposed. Non-inferiority was confirmed with respect to ongoing pregnancy with rates of 31.0% vs. 25.7% for follitropin delta compared to follitropin alfa, estimated mean difference of 5.1% (95% confidence interval (CI) -1.3% to 11.5%). The clinical pregnancy rate (35.4% vs. 31.5%, P = 0.239) and live birth rate (31.0% vs. 25.5%, P = 0.101) were comparable between the follitropin delta group and the follitropin alfa group. Overall, the individualized follitropin delta treatment resulted in fewer oocytes retrieved compared to follitropin alfa treatment (10.3 ± 6.2 vs. 12.5 ± 7.5, P < 0.001), which was mainly due to fewer oocytes (10.5 ± 6.4 vs. 13.9 ± 7.8) in women with AMH ≥ 15 pmol/L. Accordingly there was a lower incidence of early ovarian hyper-stimulation syndrome (OHSS) and/or preventive interventions (6.1% vs. 11.0%, P = 0.013). A daily follitropin delta dose of 10.2 µg (95% CI: 9.3—11.2 µg) was estimated to provide the same number of oocytes retrieved as a starting dose of 150 IU/d of follitropin alfa. Conclusion: Follitropin delta in its individualized fixed-dose regimen showed similar efficacy and improved safety compared with follitropin alfa in a conventional adjustable dosing regimen in Chinese women. Clinical trial registration number: NCT03296527. [ABSTRACT FROM AUTHOR]

Background: Unique amongst brain stimulation tools, transcranial direct current stimulation (tDCS) currently lacks an easy or widely implemented method for individualizing dosage. Objective: We developed a method of reverse-calculating electric-field (E-field) models based on Magnetic Resonance Imaging (MRI) scans that can estimate individualized tDCS dose. We also evaluated an MRI-free method of individualizing tDCS dose by measuring transcranial magnetic stimulation (TMS) motor threshold (MT) and single pulse, suprathreshold transcranial electrical stimulation (TES) MT and regressing it against E-field modeling. Key assumptions of reverse-calculation E-field modeling, including the size of region of interest (ROI) analysis and the linearity of multiple E-field models were also tested. Methods: In 29 healthy adults, we acquired TMS MT, TES MT, and anatomical T1-weighted MPRAGE MRI scans with a fiducial marking the motor hotspot. We then computed a “reverse-calculated tDCS dose” of tDCS applied at the scalp needed to cause a 1.00 V/m E-field at the cortex. Finally, we examined whether the predicted E-field values correlated with each participant’s measured TMS MT or TES MT. Results: We were able to determine a reverse-calculated tDCS dose for each participant using a 5 × 5 x 5 voxel grid region of interest (ROI) approach (average = 6.03 mA, SD = 1.44 mA, range = 3.75–9.74 mA). The Transcranial Electrical Stimulation MT, but not the Transcranial Magnetic Stimulation MT, significantly correlated with the ROI-based reverse-calculated tDCS dose determined by E-field modeling (R2 = 0.45, p

Mavacamten is the first and only cardiac myosin inhibitor approved in 5 continents for the treatment of adults with symptomatic New York Heart Association class II and III obstructive hypertrophic cardiomyopathy. An evidence-based rationale was used to develop individualized mavacamten dosing, guided by commonly used clinical parameters. Echocardiography is recommended as part of routine clinical assessment of patients with hypertrophic cardiomyopathy, and left ventricular (LV) outflow tract gradient and LV ejection fraction are parameters that can be readily assessed and monitored by echocardiography. Therefore, an echocardiography-based, clinically guided dose-titration strategy was developed to optimize patient benefit from mavacamten for the treatment of symptomatic obstructive hypertrophic cardiomyopathy while minimizing the risk of LV ejection fraction reduction. Results from clinical trials paired with extensive modeling and simulation analyses support a dose-titration and monitoring strategy based on serial echocardiographic measures of Valsalva LV outflow tract gradient and LV ejection fraction. This dosing approach allows for the identification of the lowest individualized mavacamten dose and exposure required to provide improvements in LV outflow tract obstruction, functional capacity, and symptoms. Mavacamten is primarily metabolized by CYP2C19 (cytochrome P450 2C19), and CYP2C19 metabolizer phenotype has an effect on mavacamten exposure. Therefore, this approach has also been demonstrated to provide a favorable safety profile irrespective of patients' CYP2C19 metabolizer status. The dose-titration strategy includes additional considerations for the potential onset of systolic dysfunction in the context of intercurrent illness, and for the potential of drug-drug interactions with inhibitors and substrates of cytochrome P450 enzymes. This posology is reflected in the mavacamten US prescribing information.

The low incidence of vincristine-induced peripheral neuropathy (VIPN) in Kenyan children may result from low vincristine exposure. We studied vincristine exposure in Kenyan children and dose-escalated in case of low vincristine exposure (NCT05844670). Average vincristine exposure was high. Individual vincristine exposure was assessed with a previously developed nomogram. A 20% dose increase was recommended for participants with low exposure and no VIPN, hyperbilirubinemia, or malnutrition. None of the 15 participants developed VIPN. Low vincristine exposure was seen in one participant: a dose increase was implemented without side effects. In conclusion, the participants did not develop VIPN despite having high vincristine exposure., (© 2024 The Author(s). Pediatric Blood & Cancer published by Wiley Periodicals LLC.)

[Display omitted] Recently, APV organized in collaboration with Fette Compacting GmbH a course on current use and future opportunities of minitablets. The course including a workshop was attended by 30 participants and focused on the manufacturing, packaging, characterization and medical use of minitablets. It took place at the Headquarter of Fette Compacting GmbH in Schwarzenbek. This article provides an overview on the topics presented and discussed during the course. [ABSTRACT FROM AUTHOR]

• Follitropin delta was individualized based on anti-Müllerian hormone concentration and body weight in Japanese women. • Non-inferiority was shown between follitropin delta and beta in terms of number of oocytes. • Individualized dosing significantly reduced rates of ovarian hyperstimulation syndrome. • Individualized dosing showed a favourable benefit–risk profile in fresh cycles. This study aimed to establish the efficacy and safety of ovarian stimulation with a follitropin delta individualized fixed-dose regimen based on serum anti-Müllerian hormone (AMH) concentration and body weight versus conventional follitropin beta dosing in Japanese women. This randomized, controlled, assessor-blind, multicentre, non-inferiority trial was conducted in 347 Japanese IVF/intracytoplasmic sperm injection patients. They were randomized to individualized follitropin delta (AMH <15 pmol/l: 12 µg/day; AMH ≥15 pmol/l: 0.10–0.19 µg/kg/day; minimum 6 µg/day; maximum 12 µg/day) or conventional follitropin beta (150 IU/day for the first 5 days, with potential subsequent dose adjustments). The primary end-point was the number of oocytes retrieved with a pre-specified non-inferiority margin (−3.0 oocytes). The primary trial objective was met, as non-inferiority was established for number of oocytes retrieved for individualized follitropin delta dosing compared with conventional follitropin beta dosing (9.3 versus 10.5; lower boundary of 95% confidence interval −2.3). The occurrence of ovarian hyperstimulation syndrome (OHSS) was reduced to approximately half with individualized compared with conventional dosing, with an incidence of 11.2% versus 19.8% (P = 0.021) for OHSS of any grade and 7.1% versus 14.1% (P = 0.027) for moderate/severe OHSS. The live birth rate per started cycle was 23.5% for individualized dosing and 18.6% for conventional dosing. Dosing with individualized follitropin delta in Japanese women is non-inferior to conventional dosing with follitropin beta for number of oocytes retrieved. The individualized approach shows a favourable benefit–risk profile, providing a statistically significant and clinically relevant reduction in the incidence of OHSS, without compromising live birth rates. [Display omitted] [ABSTRACT FROM AUTHOR]

It remains unclear whether therapeutic drug monitoring (TDM) of pazopanib improves treatment outcomes in routine clinical practice. We did a prospective cohort study to evaluate the benefits of TDM for pazopanib therapy in real‐world practice. Among 25 patients with pharmacokinetically guided dosing, only 5 (20%, 95% confidence interval 6.8–40.7%) discontinued treatment because of adverse events. However, 5 (41.7%, 95% confidence interval 15.2–72.3%) of historical controls including 12 patients not receiving such a strategy experienced adverse events leading to early termination. PK‐guided dosing significantly increased median time‐to‐treatment discontinuation (252 vs 74 days, P =.012) with reduced toxicity and improved overall survival (not reached vs 313 days, P =.002) relative to conventional dosing in the control group. In conclusion, PK‐guided dose adaptation through the use of TDM has the potential to improve treatment outcomes of pazopanib in routine clinical practice, warranting larger, randomized studies. [ABSTRACT FROM AUTHOR]

Model-informed precision dosing (MIPD) has become synonymous with modern approaches for individualizing drug therapy, in which the characteristics of each patient are considered as opposed to applying a one-size-fits-all alternative. This review provides a brief account of the current knowledge, practices, and opinions on MIPD while defining an achievable vision for MIPD in clinical care based on available evidence. We begin with a historical perspective on variability in dose requirements and then discuss technical aspects of MIPD, including the need for clinical decision support tools, practical validation, and implementation of MIPD in health care. We also discuss novel ways to characterize patient variability beyond the common perceptions of genetic control. Finally, we address current debates on MIPD from the perspectives of the new drug development, health economics, and drug regulations. [ABSTRACT FROM AUTHOR]

The administered dose of a drug modulates whether patients will experience optimal effectiveness, toxicity including death, or no effect at all. Dosing is particularly important for diseases and/or drugs where the drug can decrease severe morbidity or prolong life. Likewise, dosing is important where the drug can cause death or severe morbidity. Since we believe there are many examples where more precise dosing could benefit patients, it is worthwhile to consider how to prioritize drug–disease targets. One key consideration is the quality of information available from which more precise dosing recommendations can be constructed. When a new more precise dosing scheme is created and differs significantly from the approved label, it is important to consider the level of proof necessary to either change the label and/or change clinical practice. The cost and effort needed to provide this proof should also be considered in prioritizing drug–disease precision dosing targets. Although precision dosing is being promoted and has great promise, it is underutilized in many drugs and disease states. Therefore, we believe it is important to consider how more precise dosing is going to be delivered to high priority patients in a timely manner. If better dosing schemes do not change clinical practice resulting in better patient outcomes, then what is the use? This review paper discusses variables to consider when prioritizing precision dosing candidates while highlighting key examples of precision dosing that have been successfully used to improve patient care.

IntroductionAt tamoxifen standard dosing, ∼20% of breast cancer patients do not reach proposed target endoxifen concentrations >5.97 ng/mL. Thus, better understanding the large interindividual variability in tamoxifen pharmacokinetics (PK) is crucial. By applying non-linear mixed-effects (NLME) modeling to a pooled ‘real-world’ clinical PK database, we aimed to (i) dissect several levels of variability and identify factors predictive for endoxifen exposure and (ii) assess different tamoxifen dosing strategies for their potential to increase the number of patients reaching target endoxifen concentrations.MethodsTamoxifen and endoxifen concentrations with genetic and demographic data of 468 breast cancer patients from six reported studies were used to develop a NLME parent-metabolite PK model. Different levels of variability on model parameters or measurements were investigated and the impact of covariates thereupon explored. The model was subsequently applied in a simulation-based comparison of three dosing strategies with increasing degree of dose individualization for a large virtual breast cancer population. Interindividual variability of endoxifen concentrations and the fraction of patients at risk for not reaching target concentrations were assessed for each dosing strategy.Results and ConclusionsThe integrated NLME model enabled to differentiate and quantify four levels of variability (interstudy, interindividual, interoccasion, and intraindividual). Strong influential factors, i.e., CYP2D6 activity score, drug–drug interactions with CYP3A and CYP2D6 inducers/inhibitors and age, were reliably identified, reducing interoccasion variability to

Unique amongst brain stimulation tools, transcranial direct current stimulation (tDCS) currently lacks an easy or widely implemented method for individualizing dosage. We developed a method of reverse-calculating electric-field (E-field) models based on Magnetic Resonance Imaging (MRI) scans that can estimate individualized tDCS dose. We also evaluated an MRI-free method of individualizing tDCS dose by measuring transcranial magnetic stimulation (TMS) motor threshold (MT) and single pulse, suprathreshold transcranial electrical stimulation (TES) MT and regressing it against E-field modeling. Key assumptions of reverse-calculation E-field modeling, including the size of region of interest (ROI) analysis and the linearity of multiple E-field models were also tested. In 29 healthy adults, we acquired TMS MT, TES MT, and anatomical T1-weighted MPRAGE MRI scans with a fiducial marking the motor hotspot. We then computed a "reverse-calculated tDCS dose" of tDCS applied at the scalp needed to cause a 1.00 V/m E-field at the cortex. Finally, we examined whether the predicted E-field values correlated with each participant's measured TMS MT or TES MT. We were able to determine a reverse-calculated tDCS dose for each participant using a 5 × 5 x 5 voxel grid region of interest (ROI) approach (average = 6.03 mA, SD = 1.44 mA, range = 3.75–9.74 mA). The Transcranial Electrical Stimulation MT, but not the Transcranial Magnetic Stimulation MT, significantly correlated with the ROI-based reverse-calculated tDCS dose determined by E-field modeling (R2 = 0.45, p < 0.001). Reverse-calculation E-field modeling, alone or regressed against TES MT, shows promise as a method to individualize tDCS dose. The large range of the reverse-calculated tDCS doses between subjects underscores the likely need to individualize tDCS dose. Future research should further examine the use of TES MT to individually dose tDCS as an MRI-free method of dosing tDCS. • Reverse-calculation electric-field modeling can estimate individualized tDCS doses. • Individualized tDCS doses widely vary (range: 3.75–9.74 mA to produce 1 V/m). • TDCS applied at a uniform 1–2 mA dose may underdose some individuals. • Transcranial electrical stimulation (TES) motor thresholds (MTs) correlate with reverse-calculation tDCS doses (p < 0.001). • TES MT or reverse-calculation modeling could become methods to individually dose tDCS and warrant further investigation. [ABSTRACT FROM AUTHOR]

The administered dose of a drug modulates whether patients will experience optimal effectiveness, toxicity including death, or no effect at all. Dosing is particularly important for diseases and/or drugs where the drug can decrease severe morbidity or prolong life. Likewise, dosing is important where the drug can cause death or severe morbidity. Since we believe there are many examples where more precise dosing could benefit patients, it is worthwhile to consider how to prioritize drug–disease targets. One key consideration is the quality of information available from which more precise dosing recommendations can be constructed. When a new more precise dosing scheme is created and differs significantly from the approved label, it is important to consider the level of proof necessary to either change the label and/or change clinical practice. The cost and effort needed to provide this proof should also be considered in prioritizing drug–disease precision dosing targets. Although precision dosing is being promoted and has great promise, it is underutilized in many drugs and disease states. Therefore, we believe it is important to consider how more precise dosing is going to be delivered to high priority patients in a timely manner. If better dosing schemes do not change clinical practice resulting in better patient outcomes, then what is the use? This review paper discusses variables to consider when prioritizing precision dosing candidates while highlighting key examples of precision dosing that have been successfully used to improve patient care. [ABSTRACT FROM AUTHOR]

Background: Various pharmacokinetic (PK) equations and software have been developed to individualize vancomycin dosing. However, the benefit of using any PK information to guide vancomycin dosing has not been fully elucidated. Objective: To appraise available evidence on the effectiveness and safety of individualized vancomycin dosing via PK tools. Methods: PubMed, EMBASE, the Cochrane Library, and 2 Chinese literature databases were searched through August 1, 2019. Randomized controlled trials (RCTs) and cohort studies that reported the PK and clinical outcomes of individualized vancomycin dosing versus empirical dosing were included. Pooled risk ratios (RRs) and mean differences were calculated for dichotomous and continuous outcomes, respectively. Results: A total of 21 studies involving 4346 patients were finally included, of which 3 were RCTs and 18 were cohort studies. Meta-analysis revealed that PK-guided vancomycin dosing significantly increased the attainment of target trough concentration (RR = 1.59; 95% CI = 1.49-1.70) and decreased the incidence of nephrotoxicity (RR = 0.57; 95% CI = 0.46-0.71). Additionally, the available evidence showed that target area under the curve/minimum inhibitory concentration attainment rate and time to target concentration could improve. However, the evidence on clinical outcomes was scarce, and no significant differences were detected in clinical response rate, microbiological eradication rate, mortality, and length of hospital stay between PK-guided vancomycin dosing and empirical dosing strategies. Conclusion and Relevance: Individualized vancomycin dosing via PK tools significantly increases the attainment of target trough concentration and decreases the incidence of nephrotoxicity. Evidence on clinical effectiveness was limited and showed no significant benefit. Further well-designed studies are warranted to assess its clinical effectiveness and inform routine care. [ABSTRACT FROM AUTHOR]

Introduction: At tamoxifen standard dosing, ∼20% of breast cancer patients do not reach proposed target endoxifen concentrations >5.97 ng/mL. Thus, better understanding the large interindividual variability in tamoxifen pharmacokinetics (PK) is crucial. By applying non-linear mixed-effects (NLME) modeling to a pooled 'real-world' clinical PK database, we aimed to (i) dissect several levels of variability and identify factors predictive for endoxifen exposure and (ii) assess different tamoxifen dosing strategies for their potential to increase the number of patients reaching target endoxifen concentrations. Methods: Tamoxifen and endoxifen concentrations with genetic and demographic data of 468 breast cancer patients from six reported studies were used to develop a NLME parent-metabolite PK model. Different levels of variability on model parameters or measurements were investigated and the impact of covariates thereupon explored. The model was subsequently applied in a simulation-based comparison of three dosing strategies with increasing degree of dose individualization for a large virtual breast cancer population. Interindividual variability of endoxifen concentrations and the fraction of patients at risk for not reaching target concentrations were assessed for each dosing strategy. Results and Conclusions: The integrated NLME model enabled to differentiate and quantify four levels of variability (interstudy, interindividual, interoccasion, and intraindividual). Strong influential factors, i.e., CYP2D6 activity score, drug–drug interactions with CYP3A and CYP2D6 inducers/inhibitors and age, were reliably identified, reducing interoccasion variability to <20% CV. Yet, unexplained interindividual variability in endoxifen formation remained large (47.2% CV). Hence, therapeutic drug monitoring seems promising for achieving endoxifen target concentrations. Three tamoxifen dosing strategies [standard dosing (20 mg QD), CYP2D6-guided dosing (20, 40, and 60 mg QD) and individual model-informed precision dosing (MIPD)] using three therapeutic drug monitoring samples (5–120 mg QD) were compared, leveraging the model. The proportion of patients at risk for not reaching target concentrations was 22.2% in standard dosing, 16.0% in CYP2D6-guided dosing and 7.19% in MIPD. While in CYP2D6-guided- and standard dosing interindividual variability in endoxifen concentrations was high (64.0% CV and 68.1% CV, respectively), it was considerably reduced in MIPD (24.0% CV). Hence, MIPD demonstrated to be the most promising strategy for achieving target endoxifen concentrations. [ABSTRACT FROM AUTHOR]

Optimizing drug dosages is essential for effective treatment. Clinical protocols may not suit all types of patients evenly, due to many drug trials not being designed to account for all comorbities or clinically relevant outcomes. Methodologies to optimize drug policies with observational data exist, but struggle due to limited data completeness in clinical settings. Computational methods can help overcome these challenges by leveraging field knowledge. This paper proposes an Individualized Doser (IDoser), a core dosing model that links drug dose to relevant covariates via a set of coefficients and includes a loss function to code needed assumptions and requirements. Coordinate descent is used to obtain a fitted model with minimal loss. The loss function also measures performance when validating the model with unseen data. We validated the proposed approach using the case of follicle-stimulating hormone (FSH) dosing for controlled ovarian stimulation (COS). When compared to clinical practice, IDoser achieved a net improvement of up to 31.97% in the validation cases. We present a simple but effective method to bridge the gap between current clinical dosing policies and gold policies based on the true underlying and often unknown dose–response functions. [Display omitted] • IDoser allows to incorporate domain knowledge in the dosing model. • The search for policy solutions is customizable depending on the dosing problem. • For FSH dosing, up to 31.97% improvement was observed against a clinical practice. • Its flexible capabilities indicate potential applicability for similar problems. [ABSTRACT FROM AUTHOR]

Background: Due to the heterogeneity of critically ill patients, the pharmacokinetics of tigecycline are unclear, and the optimal dosing strategy is controversial. Methods: A single-center prospective clinical study that included critically ill patients who received tigecycline was performed. Blood samples were intensively sampled (eight samples each), and plasma drug concentrations were determined. A population pharmacokinetic (PPK) model was developed and evaluated by goodness-of-fit plots, bootstrap analysis and visual predictive checks. Monte Carlo simulation was conducted to optimize the dosage regimen. Results: Overall, 751 observations from 98 patients were included. The final PPK model was a two-compartment model incorporating covariates of creatinine clearance on clearance (CL), body weight on both central and peripheral volumes of distribution (V1 and V2), γ-glutamyl transferase and total bilirubin on intercompartment clearance (Q), and albumin on V2. The typical values of CL, Q, V1 and V2 were 3.09 L/h, 39.7 L/h, 32.1 L and 113 L, respectively. A dosage regimen of 50 mg/12 h was suitable for complicated intra-abdominal infections, but 100 mg/12 h was needed for community-acquired pneumonia, skin and skin structure infections and infections caused by less-susceptive bacteria. Conclusion: The Tigecycline PPK model was successfully developed and validated. Individualized dosing of tigecycline could be beneficial for critically ill patients., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Su, Song, Liu, Yu, Feng, Wu, Guo and Yu.)

Topical drug delivery is widely used in various diseases because of the advantages of not passing through the gastrointestinal tract, avoiding gastrointestinal irritation and hepatic first-pass effect, and reaching the lesion directly to reduce unnecessary adverse reactions. The skin helps the organism to defend itself against a huge majority of external aggressions and is one of the most important lines of defense of the body. However, the skin's strong barrier ability is also a huge obstacle to the effectiveness of topical medications. Allowing the bioactive, composition in a drug to pass through the stratum corneum barrier as needed to reach the target site is the most essential need for the bioactive, composition to exert its therapeutic effect. The state of the skin barrier, the choice of delivery system for the bioactive, composition, and individualized disease detection and dosing planning influence the effectiveness of topical medications. Nowadays, enhancing transdermal absorption of topically applied drugs is the hottest research area. However, enhancing transdermal absorption of drugs is not the first choice to improve the effectiveness of all drugs. Excessive transdermal absorption enhances topical drug accumulation at non-target sites and the occurrence of adverse reactions. This paper introduces topical drug delivery strategies to improve drug effectiveness from three perspectives: skin barrier, drug delivery system and individualized drug delivery, describes the current status and shortcomings of topical drug research, and provides new directions and ideas for topical drug research., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhao, Chen, Bai, Song, Zhang, Yu, Huang, Wang and Lu.)

Background: The MeroRisk-calculator, an easy-to-use tool to determine the risk of meropenem target non-attainment after standard dosing (1000 mg; q8h), uses a patient’s creatinine clearance and the minimum inhibitory concentration (MIC) of the pathogen. In clinical practice, however, the MIC is rarely available. The objectives were to evaluate the MeroRisk-calculator and to extend risk assessment by including general pathogen sensitivity data. Methods: Using a clinical routine dataset (155 patients, 891 samples), a direct data-based evaluation was not feasible. Thus, in step 1, the performance of a pharmacokinetic model was determined for predicting the measured concentrations. In step 2, the PK model was used for a model-based evaluation of the MeroRisk-calculator: risk of target non-attainment was calculated using the PK model and agreement with the MeroRisk-calculator was determined by a visual and statistical (Lin’s concordance correlation coefficient (CCC)) analysis for MIC values 0.125–16 mg/L. The MeroRisk-calculator was extended to include risk assessment based on EUCAST-MIC distributions and cumulative-fraction-of-response analysis. Results: Step 1 showed a negligible bias of the PK model to underpredict concentrations (−0.84 mg/L). Step 2 revealed a high level of agreement between risk of target non-attainment predictions for creatinine clearances >50 mL/min (CCC = 0.990), but considerable deviations for patients

Purpose: While in the era of precision medicine, the right drug for each patient is selected based on molecular tumor characteristics, most novel oral targeted anticancer agents are still being administered using a one-size-fits-all fixed dosing approach. In this review, we discuss the scientific evidence for dose individualization of oral targeted therapies in oncology, based on therapeutic drug monitoring (TDM). Methods: Based on literature search and our own experiences, seven criteria for drugs to be suitable candidates for TDM will be addressed: (1) absence of an easily measurable biomarker for drug effect; (2) long-term therapy; (3) availability of a validated sensitive bioanalytical method; (4) significant variability in pharmacokinetic exposure; (5) narrow therapeutic range; (6) defined and consistent exposure-response relationships; (7) feasible dose-adaptation strategies. Results: All of these requirements are met for most oral targeted therapies in oncology. Also, prospective studies have already shown TDM to be feasible for imatinib, pazopanib, sunitinib, everolimus, and endoxifen. Conclusions: In order to realize the full potential of personalized medicine in oncology, patients should not only be treated with the right drug, but also at the right dose. TDM could be a suitable tool to achieve this. [ABSTRACT FROM AUTHOR]

Summary: Objective: The stability of anti‐Müllerian hormone (AMH) across and between menstrual cycles has been the subject of debate. The objective of this analysis was to study the inter‐ and intracycle variability in repeated measurements and assess the impact on an individualized gonadotropin dosing algorithm and predicted oocyte yield. Design: Retrospective analysis of repeat AMH measures from a randomized controlled trial. Patients: A total of 1326 women aged 18‐40 years. Measurements: Serum AMH levels at screening and at cycle day 2‐3 in up to three ovarian stimulation cycles. AMH variability and its impact on gonadotropin dose and the predicted number of oocytes. Results: Repeat serum AMH measurements were strongly correlated within individual women (correlation coefficient 0.92). AMH exhibited limited within‐subject variation (coefficient of variation 23%), a small time‐related decline (mean 6% decrease/y), but no systematic variation across the menstrual cycle. Irrespective of whether the AMH screening value or the AMH at the initiation of ovarian stimulation was used, for women with an AMH level <15 pmol/L, 93% would receive the same gonadotropin dose and attain an identical number of oocytes in 97% of cases. For women with an AMH level ≥15 pmol/L, 80% would receive an individualized dose within ±1.5 μg and 90% would attain ±1 oocyte. Conclusion: AMH variability had limited impact on individualized gonadotropin dosing, with 95% of women predicted to obtain an oocyte yield that does not vary beyond 1 oocyte count, irrespective of whether a random or early follicular AMH measurement was used to determine the individualized gonadotropin dose. [ABSTRACT FROM AUTHOR]

Because of increasing antimicrobial resistance and the shortage of new antibiotics, there is a growing need to optimize the use of old and new antibiotics. Modelling of the pharmacokinetic/pharmacodynamic (PK/PD) characteristics of antibiotics can support the optimization of dosing regimens. Antimicrobial efficacy is determined by susceptibility of the drug to the microorganism and exposure to the drug, which relies on the PK and the dose. Population PK models describe relationships between patients characteristics and drug exposure. This article highlights three clinical applications of these models applied to antibiotics: 1) dosing evaluation of old antibiotics, 2) setting clinical breakpoints and 3) dosing individualization using therapeutic drug monitoring (TDM). For each clinical application, challenges regarding interpretation are discussed. An important challenge is to improve the understanding of the interpretation of modelling results for good implementation of the dosing recommendations, clinical breakpoints and TDM advices. Therefore, also background information on PK/PD principles and approaches to analyse PK/PD data are provided. [ABSTRACT FROM AUTHOR]

Aim Fixed dose oral tyrosine kinase inhibitors imatinib, sunitinib and pazopanib show a high interpatient variability in plasma exposure. A relationship between plasma exposure and treatment outcome has been established, which supports the rationale for dose optimization of these drugs. The aim of this study was to monitor how many patients reached adequate trough levels after therapeutic drug monitoring-based dose optimization in daily practice. Methods A cohort study was performed in patients treated with imatinib, sunitinib or pazopanib of whom follow-up drug levels were measured between August 2012 and April 2016. Patients' characteristics were collected by reviewing electronic patient records. Drug levels were measured using high-performance liquid chromatography coupled with tandem mass spectrometry and trough levels were estimated using a predefined algorithm. Dose interventions were proposed based on trough levels. Results In total, 396 trough levels were determined in 109 patients. Median sample frequency per patient was 3. During the first measurement only 38% of patients showed trough levels within the predefined target ranges despite standard dosing; 52% of the patients showed drug levels below and 10% above the target range. In 35 out of 41 patients (85%) dose interventions led to adequate trough levels. Eventually, 64% of the total cohort reached adequate trough levels. Conclusions Dose optimization proved an effective tool to reach adequate trough levels in patients treated with imatinib, sunitinib and pazopanib. The percentage of patients with adequate trough levels increased from 38 to 64%. Therapeutic drug monitoring may add to the improvement of efficacy and reduction of toxicity and costs of these treatments. [ABSTRACT FROM AUTHOR]