Clinical improvement in psoriasis with specific targeting of interleukin-23.

Psoriasis is a chronic inflammatory skin disorder that affects approximately 2-3% of the population worldwide and has severe effects on patients' physical and psychological well-being. The discovery that psoriasis is an immune-mediated disease has led to more targeted, effective therapies; recent advances have focused on the interleukin (IL)-12/23p40 subunit shared by IL-12 and IL-23. Evidence suggests that specific inhibition of IL-23 would result in improvement in psoriasis. Here we evaluate tildrakizumab, a monoclonal antibody that targets the IL-23p19 subunit, in a three-part, randomized, placebo-controlled, sequential, rising multiple-dose phase I study in patients with moderate-to-severe psoriasis to provide clinical proof that specific targeting of IL-23p19 results in symptomatic improvement of disease severity in human subjects. A 75% reduction in the psoriasis area and severity index (PASI) score (PASI75) was achieved by all subjects in parts 1 and 3 (pooled) in the 3 and 10 mg kg(-1) groups by day 196. In part 2, 10 out of 15 subjects in the 3 mg kg(-1) group and 13 out of 14 subjects in the 10 mg kg(-1) group achieved a PASI75 by day 112. Tildrakizumab demonstrated important clinical improvement in moderate-to-severe psoriasis patients as demonstrated by improvements in PASI scores and histological samples.

Food-effect study of nilotinib in chronic myeloid leukaemia (NiFo study): Enabling dose reduction and relief of treatment burden.

OBJECTIVES: Taking advantage of its food-dependent bioavailability, the present study investigated the effect of a reduced dose taken with real-life meals on the pharmacokinetics (PK) of nilotinib in chronic myeloid leukaemia (CML) patients. METHODS: Nilotinib was taken fasted (300 mg BID, days 1-4) or with real-life meals (200 mg BID, days 5-11). Rich sampling (days 1, 3, 8, 11) allowed for non-compartmental PK analysis. Nilotinib exposure (AUC0-12 h  -Cmin -Cmax ) and its intra- and interpatient variability were compared between the two regimens. Adverse events were recorded by means of a patient diary and ECG monitoring. RESULTS: Fifteen patients aged 40-74 years participated. Nilotinib PK following 200 mg BID taken with a meal strongly resembled that of 300 mg BID taken fasted (Cmin percentile (P)10-P90: 665-1404 ng/mL and 557-1743 ng/mL, respectively). Meals delayed nilotinib absorption. Intra- and interpatient variability were not increased by intake with meals. Nilotinib with food was well tolerated. CONCLUSION: With support of therapeutic drug monitoring, the use of a reduced 200 mg nilotinib dose with real-life meals seems feasible and safe. Future (confirmatory) studies should further explore the usefulness of nilotinib dosing together with food, including the relationship with treatment efficacy as well as long-term effects on quality of life. CLINICAL TRIAL REGISTRATION: NTR5000 (Netherlands Trial Register, www.trialregister.nl).

Impact of patient characteristics on the pharmacokinetics of corifollitropin alfa during controlled ovarian stimulation.

AIM: The aim of the present study was to characterize the pharmacokinetic profile of corifollitropin alfa and examine the relationships between dose, intrinsic factors [body weight, body mass index (BMI), age and race] and corifollitropin alfa pharmacokinetics. METHODS: Data from five phase II and III clinical trials of corifollitropin alfa were evaluated. All subjects included in the analysis received 60 - 180 µg corifollitropin alfa for controlled ovarian stimulation in a gonadotrophin-releasing hormone antagonist protocol followed by daily recombinant follicle stimulating hormone (rFSH) from day 8 onwards. Serum corifollitropin alfa levels (across the entire range of treatment) and total follicle stimulating hormone immunoreactivity levels (up to the start of rFSH treatment) were indicators of drug exposure. The analyses were performed using a nonlinear mixed-effects modelling approach. RESULTS: A total of 2630 subjects were treated with corifollitropin alfa, and 2557 subjects were evaluable for analysis. Body weight, BMI and race (Asian and Black vs. Caucasian) were significant determinants of corifollitropin alfa exposure. Dose-normalized corifollitropin alfa exposure was ~89% higher in women with a body weight of 50 kg vs. 90 kg (in subjects with a similar BMI of 24 kg m(-2) ); 14% higher in women with a BMI of 18 kg m(-2) vs. 32 kg m(-2) (provided they were of similar body weight); and ~15.7% lower in Asian subjects and 13% higher in Black subjects vs. Caucasian subjects. CONCLUSIONS: Body weight was the major determinant of corifollitropin alfa exposure; BMI and race (Asian and Black) were also determinants but to a lesser extent and without associated effects on clinical outcomes. Corifollitropin alfa dose adjustment is indicated, based on body weight but not for BMI or race. These recommendations are consistent with the product label.

Single therapeutic and supratherapeutic doses of corifollitropin alfa, a sustained follicle stimulant, do not prolong the QTcF-interval in healthy postmenopausal volunteers.

OBJECTIVE: Corifollitropin alfa (Elonva®) is the first hybrid follicle-stimulating hormone molecule with demonstrated sustained follicle-stimulating activity after a single subcutaneous injection. This trial evaluated if corifollitropin alfa is associated with QT/QTc prolongation and/ or proarrhythmic potential as compared to placebo in healthy post-menopausal women. MATERIALS: Participants were healthy, postmenopausal women. Study treatments were corifollitropin alfa 150 µg, corifollitropin alfa 240 µg, and moxifloxacin 400 mg with placebo. METHODS: This randomized, double blind, double-dummy, 4-period crossover trial compared single doses of corifollitropin alfa 150 µg (therapeutic dose), corifollitropin alfa 240 µg (supratherapeutic dose), and moxifloxacin 400 mg (positive control) with placebo. Corifollitropin alfa was administered on day 1 and moxifloxacin on day 2. RESULTS: The largest time-matched mean QTcF difference versus placebo for the therapeutic dose of corifollitropin alfa was 1.4 ms (upper limit of 1-sided 95% confidence interval (UL 95% CI) = 3.4 ms), and for the supratherapeutic dose was 1.2 ms (UL 95% CI = 3.6 ms). CONCLUSIONS: For both the therapeutic and the supratherapeutic dose of corifollitropin alfa and at all time points, the UL 95% CI for the time matched QTcF differences compared with placebo was below 10 ms, the threshold of relevance defined by the ICH E14 guideline. Single therapeutic and supratherapeutic doses of corifollitropin alfa are not associated with clinically relevant QT/QTc-interval prolongation in healthy post-menopausal women.

Tildrakizumab, a novel anti-IL-23 monoclonal antibody, is unaffected by ethnic variability in Caucasian, Chinese, and Japanese subjects.

OBJECTIVE: To evaluate the effect of ethnicity on the pharmacokinetics (PK) of tildrakizumab, a novel anti-IL-23 monoclonal antibody for the treatment of psoriasis. MATERIALS AND METHODS: This was an open-label, 2-part study in healthy adult subjects. In part 1, Japanese subjects and matched Caucasian and Chinese subjects (to Japanese) were assigned to 1 of 3 cohorts and administered tildrakizumab 50, 200, or 400 mg subcutaneously (SC). In part 2, Japanese subjects received tildrakizumab 10 mg/kg IV. Pre- and post-treatment antidrug antibodies were assessed. Safety and tolerability were assessed throughout the study. RESULTS: 59 subjects were enrolled; 53 in part 1 and 6 in part 2. Overall geometric mean AUC∞ was 6.15, 6.05, and 6.32 day×µg/mL/mg in Japanese, Caucasian, and Chinese subjects, respectively, after administration of a single SC dose. Bioavailability was ~92%. Six out of 58 evaluable subjects were positive for post-treatment ADA; 2 of these positive subjects had reduced tildrakizumab exposure. Most AEs were mild in intensity and the most frequent treatment-related AEs were injection site hematoma (15%), injection site pain (10%), and injection site erythema (8%). CONCLUSIONS: The pharmacokinetics of tildrakizumab were similar in Japanese, Caucasian, and Chinese subjects. Tildrakizumab exposure increased proportionally with dose in the range of 50-400 mg. A single SC dose of 50, 200, and 400 mg or a single IV dose of 10 mg/kg was generally well tolerated.

Population PK and Semimechanistic PK/PD Modeling and Simulation of Relugolix Effects on Testosterone Suppression in Men with Prostate Cancer.

Relugolix, the first orally active, nonpeptide gonadotropin-releasing hormone receptor antagonist, is approved in the United States and the European Union for the treatment of adult patients with advanced prostate cancer. The recommended dosing regimen is a 360-mg loading dose followed by a 120-mg daily dose. Relugolix and testosterone concentration data and clinical information from two phase I studies, two phase II studies, and the phase III safety and efficacy study (HERO) were used to develop a population pharmacokinetic (PopPK) model and a semimechanistic population pharmacokinetic/pharmacodynamic (PopPK/PD) model that characterized relugolix exposure and its relationship to testosterone concentrations. Age, body weight, and Black/African American race had at most minimal effects on relugolix exposure or testosterone concentrations with no clinical relevance. Simulations using the PopPK/PD model confirmed the recommended dosing regimen of relugolix, with the median simulated testosterone concentrations predicted to achieve castration levels (< 50 ng/dL) and profound castration levels (< 20 ng/dL) by day 2 and day 9, respectively, and demonstrated that 97.3% and 85.5% of the patients remained at castration levels (< 50 ng/dL) upon temporary interruption of treatment for 7 days and 14 days, respectively. Collectively, simulations based on the PopPK and PopPK/PD models were consistent with actual data from clinical studies, reflecting the high predictiveness of the models and supporting the reliability of model-based simulations. These models can be used to provide guidance regarding dosing recommendations under various circumstances (e.g., temporary interruption of treatment, if needed) for relugolix.

Two-stage model-based design of cancer phase I dose escalation trials: evaluation using the phase I program of barasertib (AZD1152).

INTRODUCTION: Modeling and simulation of pharmacokinetics and pharmacodynamics has previously been shown to be potentially useful in designing Phase I programs of novel anti-cancer agents that show hematological toxicity. In this analysis, a two-stage model-based trial design was evaluated retrospectively using data from the Phase I program with the aurora kinase inhibitor barasertib. METHODS: Data from two Phase I trials and four regimens were used (n = 79). Using barasertib-hydroxy QPA plasma concentrations and neutrophil count data from only study 1A, a PKPD model was developed and subsequently used to predict the MTD and a safe starting dose for the other trials. RESULTS: The PKPD model based on data from the first study adequately described the time course of neutrophil count fluctuation. The two-stage model-based design provided safe starting doses for subsequent phase I trials for barasertib. Predicted safe starting dose levels were higher than those used in two subsequent trials, but lower than used in the other trial. DISCUSSION: The two-stage approach could have been applied safely to define starting doses for alternative dosing strategies with barasertib. The limited improvement in efficiency for the phase I program of barasertib may have been due to the fact that starting doses for the studied phase I trials were already nearly optimal. CONCLUSION: Application of the two-stage model-based trial design in Phase I programs with novel anti-cancer drugs that cause haematological toxicity is feasible, safe, and may lead to a reduction in the number of patient treated at sub-therapeutic dose-levels.

Corifollitropin alfa doses based on body weight: clinical overview of drug exposure and ovarian response.

Corifollitropin alfa is a new recombinant gonadotrophin with a different pharmacokinetic profile but similar pharmacodynamic properties to conventional recombinant FSH. A single dose of corifollitropin alfa sustains multiple follicular development during the first 7 days of ovarian stimulation. This review is based on results of phase II and III trials testing the selected dose of 150 µg corifollitropin alfa in subjects >60 kg and 100 µg in subjects ≤60 kg. Exposure to corifollitropin alfa is inversely related to bodyweight. The selected doses of 100 and 150 µg in subjects weighing ≤60 and >60 kg, respectively, provide, on average, equal drug exposure producing similar ovarian responses in terms of the number of growing follicles, serum oestradiol, inhibin B and number of oocytes retrieved. Clinicians treating IVF patients with corifollitropin alfa should alter their treatment paradigm as a lower or higher dose than recommended according to body weight does not affect the ovarian response, which depends mainly on the ovarian reserve. After decades of daily dosing with FSH preparations, corifollitropin alfa allows a simpler IVF treatment regime with fewer injections. Successful use of corifollitropin alfa requires assessment of patient suitability and dosing before the start of stimulation.

Pharmacokinetics and follicular dynamics of corifollitropin alfa versus recombinant FSH during ovarian stimulation for IVF.

A single injection of corifollitropin alfa can replace seven daily injections of recombinant FSH (rFSH) using a gonadotrophin-releasing hormone antagonist protocol in ovarian stimulation prior to IVF or intracytoplasmic sperm injection. This double-blind randomized controlled trial assessed the pharmacokinetics and pharmacodynamics of 150 µg corifollitropin alfa versus daily 200 IU rFSH in 1509 patients. Comparative analyses were performed on serum concentrations of FSH immunoreactivity (pharmacokinetics), and the number and size of growing follicles, and inhibin B and oestradiol concentrations as biomarkers of ovarian response (pharmacodynamics). The rate of follicular development was similar in both treatment groups. By stimulation day 8, 33% of patients treated with corifollitropin alfa reached the criterion for human chorionic gonadotrophin (HCG) injection. The number of follicles ≥11 mm was slightly higher after corifollitropin alfa compared with daily rFSH at stimulation day 8 (difference, 1.2; 95% confidence interval (Cl) 0.5-1.8; P < 0.01) and on the day of HCG injection (difference, 2.1; 95% Cl 1.4-2.8; P < 0.01). The rise of inhibin B and oestradiol concentrations was similar in both treatment groups. Although the pharmacokinetics of corifollitropin alfa and rFSH are quite different their pharmacodynamic profiles at the dosages used are similar.

Two-stage model-based clinical trial design to optimize phase I development of novel anticancer agents.

BACKGROUND: The phase I program of anticancer agents usually consists of multiple dose escalation studies to select a safe dose for various administration schedules. We hypothesized that pharmacokinetic and pharmacodynamic (PK-PD) modeling of an initial phase I study (stage 1) can be used for selection of an optimal starting dose for subsequent studies (stage 2) and that a post-hoc PK-PD analysis enhances the selection of a recommended dose for phase II evaluation. The aim of this analysis was to demonstrate that this two-stage model-based design, which does not interfere in the conduct of trials, is safe, efficient and effective. METHODS: PK and PD data of dose escalation studies were simulated for nine compounds and for five administration regimens (stage 1) for drugs with neutropenia as dose-limiting toxicity. PK-PD models were developed for each simulated study and were used to determine a starting dose for additional phase I studies (stage 2). The model-based design was compared to a conventional study design regarding safety (number of dose-limiting toxicities (DLTs)), efficiency (number of patients treated with a dose below the recommended dose) and effectiveness (precision of dose selection). Retrospective data of the investigational anticancer drug indisulam were used to show the applicability of the model-based design. RESULTS: The model-based design was as safe as the conventional design (median number of DLTs = 3) and resulted in a reduction of the number of patients who were treated with a dose below the recommended dose (-27%, power 89%). A post-hoc model-based determination of the recommended dose for future phase II studies was more precise than the conventional selection of the recommended dose (root mean squared error 8.3% versus 30%). CONCLUSIONS: A two-stage model-based phase I design is safe for anticancer agents with dose-limiting myelosuppression and may enhance the efficiency of dose escalation studies by reducing the number of patients treated with a dose below the recommended dose and by increasing the precision of dose selection for phase II evaluation.

Pharmacokinetics and follicular dynamics of corifollitropin alfa versus recombinant FSH during ovarian stimulation for IVF.

A single injection of corifollitropin alfa can replace seven daily injections of recombinant FSH (rFSH) using a gonadotrophin-releasing hormone antagonist protocol in ovarian stimulation prior to IVF or intracytoplasmic sperm injection. This double-blind randomized controlled trial assessed the pharmacokinetics and pharmacodynamics of 150µg corifollitropin alfa versus daily 200IU rFSH in 1509 patients. Comparative analyses were performed on serum concentrations of FSH immunoreactivity (pharmacokinetics), and the number and size of growing follicles, and inhibin B and oestradiol concentrations as biomarkers of ovarian response (pharmacodynamics). The rate of follicular development was similar in both treatment groups. By stimulation day 8, 33% of patients treated with corifollitropin alfa reached the criterion for human chorionic gonadotrophin (HCG) injection. The number of follicles ⩾11mm was slightly higher after corifollitropin alfa compared with daily rFSH at stimulation day 8 (difference, 1.2; 95% confidence interval (CI) 0.5-1.8; P<0.01) and on the day of HCG injection (difference, 2.1; 95% CI 1.4-2.8; P<0.01). The rise of inhibin B and oestradiol concentrations was similar in both treatment groups. Although the pharmacokinetics of corifollitropin alfa and rFSH are quite different their pharmacodynamic profiles at the dosages used are similar. A single injection of corifollitropin alfa can replace seven daily injections of recombinant FSH (rFSH) using a gonadotrophin-releasing hormone antagonist protocol in ovarian stimulation prior to IVF or intracytoplasmic sperm injection. The objective of this study was to compare the pharmacokinetics and pharmacodynamics of corifollitropin alfa versus daily rFSH. A total of 1509 patients were randomized in a double-blind, controlled trial to either a single injection of 150µg corifollitropin alfa or to daily injections of 200IU rFSH for the first 7 days of ovarian stimulation. Serum levels of FSH immunoreactivity were analysed (pharmacokinetic analysis), together with the number and size of growing follicles and serum inhibin B and oestradiol concentrations as biomarkers of the ovarian response (pharmacodynamic analysis). Serum FSH immunoreactivity levels were higher up to stimulation day 5 for corifollitropin alfa compared with the daily rFSH regimen but were similar from day 8 onwards, when patients started rFSH if the criteria for human chorionic gonadotrophin were not yet reached. Corifollitropin alfa treatment resulted in a similar growth rate of follicles though a slightly higher number of follicles were recruited compared with daily rFSH. It is concluded that the pharmacokinetics of corifollitropin alfa and rFSH are quite different but their induced pharmacodynamic effects at the dosages used are similar.

Artificial Intelligence and Machine Learning Applied at the Point of Care.

INTRODUCTION: The increasing availability of healthcare data and rapid development of big data analytic methods has opened new avenues for use of Artificial Intelligence (AI)- and Machine Learning (ML)-based technology in medical practice. However, applications at the point of care are still scarce. OBJECTIVE: Review and discuss case studies to understand current capabilities for applying AI/ML in the healthcare setting, and regulatory requirements in the US, Europe and China. METHODS: A targeted narrative literature review of AI/ML based digital tools was performed. Scientific publications (identified in PubMed) and grey literature (identified on the websites of regulatory agencies) were reviewed and analyzed. RESULTS: From the regulatory perspective, AI/ML-based solutions can be considered medical devices (i.e., Software as Medical Device, SaMD). A case series of SaMD is presented. First, tools for monitoring and remote management of chronic diseases are presented. Second, imaging applications for diagnostic support are discussed. Finally, clinical decision support tools to facilitate the choice of treatment and precision dosing are reviewed. While tested and validated algorithms for precision dosing exist, their implementation at the point of care is limited, and their regulatory and commercialization pathway is not clear. Regulatory requirements depend on the level of risk associated with the use of the device in medical practice, and can be classified into administrative (manufacturing and quality control), software-related (design, specification, hazard analysis, architecture, traceability, software risk analysis, cybersecurity, etc.), clinical evidence (including patient perspectives in some cases), non-clinical evidence (dosing validation and biocompatibility/toxicology) and other, such as e.g. benefit-to-risk determination, risk assessment and mitigation. There generally is an alignment between the US and Europe. China additionally requires that the clinical evidence is applicable to the Chinese population and recommends that a third-party central laboratory evaluates the clinical trial results. CONCLUSIONS: The number of promising AI/ML-based technologies is increasing, but few have been implemented widely at the point of care. The need for external validation, implementation logistics, and data exchange and privacy remain the main obstacles.

Covariate-based dose individualization of the cytotoxic drug indisulam to reduce the risk of severe myelosuppression.

AIM: Chemotherapy with indisulam causes myelosuppression. This study aimed to evaluate the influence of patient-related covariates on pharmacokinetics and pharmacodynamics, to identify patients at risk for severe myelosuppression and to develop a dosing algorithm for treatment optimization. METHODS: Pharmacokinetic and pharmacodynamic data of 412 patients were available. Non-linear mixed effects modeling was used to determine the relative risk of dose-limiting myelosuppression for various covariates (demographics, physical condition, prior treatment, comedication, CYP2C genotype and biochemistry). RESULTS: Body surface area (BSA), race and CYP2C genotype had a significant impact on indisulam elimination (P < 0.001). Low BSA, Japanese race, variant CYP2C genotype, low baseline neutrophil and thrombocyte counts and female sex were clinically relevant risk factors of dose-limiting myelosuppression (RR > 1.1). A dosing strategy was developed to optimize treatment for patient subgroups. CONCLUSIONS: This study has identified covariates related to an increased risk of myelosuppression after indisulam therapy. Dose individualization may contribute to treatment optimization.

Bevacizumab for Intravitreal Injection: Impact of Sub-Visible Particles on the Shelf-Life of Repackaged Bevacizumab.

Purpose: Bevacizumab (Avastin) is a humanized monoclonal antibody approved by the European Medicines Agency for the intravenous treatment of cancer. However, it is often used as an intravitreal injection for the treatment of macular degeneration or edema. For this purpose, bevacizumab is repackaged from glass vials into plastic syringes. The formation of particles during this compounding process as well as during storage is a source of concern. The aim of this study was to test the sub-visible particulate contamination in bevacizumab material, both in the glass vial and after repackaging into polycarbonate BD Luer-Lok™ syringes. Methods: Syringes with repackaged bevacizumab from 3 different compounding hospital pharmacies were tested for sub-visible particles at different time points during storage at 2-8°C. Results: The batches of bevacizumab starting product complied with the European Pharmacopoeia (Ph. Eur.) for small-volume parenterals. Repackaging into syringes led to an immediate increase in small particles. The number of particles ≥25 µm increased 1.3-fold, and the number of particles ≥10 µm increased 5-fold, respectively. Storage of up to 37 days did not lead to an additional increase in particle counts. All batches complied with the national criteria for particles in intravitreal solutions. Conclusions: Particle count increased due to the repackaging process, but no substantial increase was observed during storage. Formation of sub-visible particles does not impact the shelf-life of bevacizumab repackaged into BD Luer-Lok syringes.

Population pharmacokinetics and pharmacodynamics for treatment optimization in clinical oncology.

Population pharmacokinetic and pharmacodynamic analysis is an important tool to support optimal treatment in clinical oncology. The population approach is suitable to explain variability between patients and to establish relationships between drug exposure and a relevant pharmacodynamic parameter. This can facilitate the selection of dosing schedules, the development of strategies for dose individualization and the application of therapeutic drug monitoring of anticancer agents. This review discusses the role of population pharmacokinetics and pharmacodynamics in clinical oncology to enhance the efficiency of drug development and to support the development of safe and effective dosing regimens for optimal treatment of cancer patients. An overview of published population studies of investigational anticancer agents and established treatment regimens is presented.

Population pharmacokinetic and pharmacodynamic analysis to support treatment optimization of combination chemotherapy with indisulam and carboplatin.

AIMS: Indisulam and carboplatin have shown synergistic activity in preclinical studies. In a dose escalation study of the combination, a treatment delay was frequently required in a 3-weekly regimen to allow recovery from myelosuppression from previous cycles. A 4-weekly regimen was better tolerated, but had a decreased dose-intensity which may compromise efficacy. The aims of this study were (i) to develop a pharmacokinetic-pharmacodynamic (PK-PD) model to describe the myelosuppressive effect of the combination, and (ii) to use this model to select a dosing regimen for Phase II evaluation. METHODS: Sixteen patients were treated at four different dose levels of indisulam (1-h infusion on day 1) and carboplatin (30-min infusion on day 2). Pharmacokinetic data were analysed with nonlinear mixed effects modelling. A semiphysiological model describing chemotherapy-induced myelosuppression characterized the relationship between the pharmacokinetics and the haematological toxicity of indisulam and carboplatin. A simulation study was performed to evaluate the tolerability and dose-intensity for 3-weekly and 4-weekly treatment regimens. RESULTS: The PK-PD model described the pharmacokinetics and the myelosuppressive effect of indisulam and carboplatin. The risk of a treatment delay at cycle 2 due to myelosuppression was unacceptably high (34-65%) in a 3-weekly regimen for various dose levels (350-600 mg m(-2) indisulam in combination with carboplatin to achieve an AUC of 4-6 mg min(-1) ml(-1)). This risk was acceptable for a 4-weekly regimen (9-24%), which is in line with the clinical study results. CONCLUSIONS: This PK-PD study supports the selection of indisulam 500 mg m(-2) and a dose of carboplatin to achieve an AUC of 6 mg min(-1) ml(-1) in a 4-weekly regimen as the recommended dose for future studies.

CYP2C9 and CYP2C19 polymorphic forms are related to increased indisulam exposure and higher risk of severe hematologic toxicity.

PURPOSE: The anticancer agent indisulam is metabolized by the cytochrome P450 of enzymes CYP2C9 and CYP2C19. Polymorphisms of these enzymes may affect the elimination rate of indisulam. Consequently, variant genotypes may be clinically relevant predictors for the risk of developing severe hematologic toxicity. The purposes of this study were to evaluate the effect of genetic variants of CYP2C9 and CYP2C19 on the pharmacokinetics of indisulam and on clinical outcome and to assess the need for pharmacogenetically guided dose adaptation. EXPERIMENTAL DESIGN: Pharmacogenetic screening of CYP2C polymorphisms was done in 67 patients treated with indisulam. Pharmacokinetic data were analyzed with a population pharmacokinetic model, in which drug elimination was described by a linear and a Michaelis-Menten pathway. The relationships between allelic variants and the elimination pharmacokinetic parameters (CL, V(max), K(m)) were tested using nonlinear mixed-effects modeling. Polymorphisms causing a high risk of dose-limiting neutropenia were identified in a simulation study. RESULTS: The Michaelis-Menten elimination rate (V(max)) was decreased by 27% (P<0.0001) for heterozygous CYP2C9*3 mutants. Heterozygous CYP2C19*2 and CYP2C19*3 mutations reduced the linear elimination rate (CL) by 38% (P < 0.0001). The risk of severe neutropenia was significantly increased by these mutations and dose reductions of 50 to 100 mg/m(2) per mutated allele may be required to normalize this risk. CONCLUSIONS: CYP2C9*3, CYP2C19*2, and CYP2C19*3 polymorphisms resulted in a reduced elimination rate of indisulam. Screening for these CYP2C polymorphisms and subsequent pharmacogenetically guided dose adaptation may assist in the selection of an optimized initial indisulam dosage.

A randomized phase II pharmacokinetic and pharmacodynamic study of indisulam as second-line therapy in patients with advanced non-small cell lung cancer.

PURPOSE: The primary aim of this study was to measure the objective tumor response rate following treatment with indisulam [E7070; N-(3-chloro-7-indolyl)-1,4-benzenedisulfonamide] as second-line therapy in patients with advanced non-small cell lung cancer. The secondary aims were to determine progression-free survival, to assess the safety and tolerability of indisulam, and to study its pharmacokinetic and pharmacodynamic profile. EXPERIMENTAL DESIGN: Patients were randomized to receive indisulam every 3 weeks either as a single i.v. dose of 700 mg/m(2) on day one (dx1) or 130 mg/m(2) given on days 1 to 5 inclusive as a daily infusion (dx5). All patients had previously received platinum-based chemotherapy. RESULTS: Forty-four patients were randomized. Only minor responses were seen. Myelosuppression, gastrointestinal symptoms, and lethargy were the most common toxicities and were more frequent in the dx1 arm. The pharmacokinetics of indisulam in each treatment schedule were adequately described using a previously developed population pharmacokinetic model and were mostly consistent with the results of the phase I program. Flow cytometric analysis of endobronchial and metastatic disease revealed a reduction in the fraction of cycling cells and an increase in apoptosis following indisulam compared with pretreatment levels. CONCLUSIONS: We conclude that, despite evidence of tumor-specific indisulam-induced apoptosis, neither of these treatment schedules has single-agent activity as second-line treatment of non-small cell lung cancer.

Vitamin C Pharmacokinetics in Critically Ill Patients: A Randomized Trial of Four IV Regimens.

BACKGROUND: Early high-dose IV vitamin C is being investigated as adjuvant therapy in patients who are critically ill, but the optimal dose and infusion method are unclear. The primary aim of this study was to describe the dose-plasma concentration relationship and safety of four different dosing regimens. METHODS: This was a four-group randomized pharmacokinetic trial. Patients who were critically ill with multiple organ dysfunction were randomized to receive 2 or 10 g/d vitamin C as a twice daily bolus infusion or continuous infusion for 48 h. End points were plasma vitamin C concentrations during 96 h, 12-h urine excretion of vitamin C, and oxalate excretion and base excess. A population pharmacokinetic model was developed using NONMEM. RESULTS: Twenty patients were included. A two-compartment pharmacokinetic model with creatinine clearance and weight as independent covariates described all four regimens best. With 2 g/d bolus, plasma vitamin C concentrations at 1 h were 29 to 50 mg/L and trough concentrations were 5.6 to 16 mg/L. With 2 g/d continuous, steady-state concentrations were 7 to 37 mg/L at 48 h. With 10 g/d bolus, 1-h concentrations were 186 to 244 mg/L and trough concentrations were 14 to 55 mg/L. With 10 g/d continuous, steady-state concentrations were 40 to 295 mg/L at 48 h. Oxalate excretion and base excess were increased in the 10 g/d dose. Forty-eight hours after discontinuation, plasma concentrations declined to hypovitaminosis levels in 15% of patients. CONCLUSIONS: The 2 g/d dose was associated with normal plasma concentrations, and the 10 g/d dose was associated with supranormal plasma concentrations, increased oxalate excretion, and metabolic alkalosis. Sustained therapy is needed to prevent hypovitaminosis. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT02455180; URL: www.clinicaltrials.gov.

Optimization of anti-infective dosing regimens during online haemodiafiltration.

Online haemodiafiltration (HDF) is increasingly used in clinical practice as a routine intermittent dialysis modality. It is well known that renal impairment and renal replacement therapy can substantially affect the pharmacokinetic behaviour of several drugs. However, surprisingly few data are available on the need for specific dose adjustments during HDF. Due to convection, drug clearance may be increased during HDF as compared with standard haemodialysis. This may be of particular interest in patients undergoing anti-infective therapy, since under-dosing may compromise patient outcomes and promote the emergence of bacterial resistance. Drug clearance during HDF is determined by (i) dialysis characteristics, (ii) drug characteristics and (iii) patient characteristics. In this review, we will discuss these different determinants of drug clearance during HDF and advise on how to adjust the dose of antibacterial, antimycotic and antiviral agents in patients undergoing HDF. In addition, the possible added value of therapeutic drug monitoring is discussed. The review provides guidance for optimization of anti-infective dosing regimens in HDF patients.