Search

BACKGROUNDCurrently, no laboratory tests exist to stratify for the risk of developing sinusoidal obstruction syndrome (SOS), an early endothelial complication after hematopoietic cell transplantation (HCT). Risk biomarkers of SOS have not been verified in a prospective cohort accounting for differences between practices across institutions. Herein, we aimed to define risk groups for SOS occurrence using 3 proteins: L-ficolin, hyaluronic acid (HA), and stimulation 2 (ST2). METHODSBetween 2017 and 2021, we prospectively accrued 80 pediatric patients across 4 US centers. Biomarkers were tested by ELISA blind to patient groupings and associated with SOS incidence on day 35 after HCT, and overall survival (OS) on day 100 after HCT. Cutpoints were identified using retrospective cohorts and applied to the prospective cohort.RESULTSCombination of the 3 biomarkers measured on day 3 after HCT in the prospective cohort provided 80% (95% CI 55%-100%) sensitivity and 73% (95% CI 62%-83%) specificity for risk of SOS occurrence. Patients with low L-ficolin were 9 times (95% CI 3-32) more likely to develop SOS, while patients with high HA and ST2 were 6.5 (95% CI 1.9-22.0) and 5.5 (95% CI 2.3-13.1) times more likely to develop SOS. These 3 markers also predicted worse day 100 OS - L-ficolin: HR, 10.0 (95% CI 2.2-45.1), P = 0.0002; HA: HR, 4.1 (95% CI 1.0-16.4), P = 0.031; and ST2: HR, 3.9 (95% CI 0.9-16.4), P = 0.04.CONCLUSIONL-ficolin, HA, and ST2 levels measured as early as 3 days after HCT improved risk stratification for SOS occurrence and OS and may guide risk-adapted preemptive therapy.TRIAL REGISTRATIONClinicalTrials.gov NCT03132337.FUNDINGNIH.

Plasma biomarkers associated with respiratory failure (RF) following hematopoietic cell transplantation (HCT) have not been identified. Therefore, we aimed to validate early (7 and 14 days post-HCT) risk biomarkers for RF. Using tandem mass spectrometry, we compared plasma obtained at day 14 post-HCT from 15 patients with RF and 15 patients without RF. Six candidate proteins, from this discovery cohort or identified in the literature, were measured by enzyme-linked immunosorbent assay in day-7 and day-14 post-HCT samples from the training (n = 213) and validation (n = 119) cohorts. Cox proportional-hazard analyses with biomarkers dichotomized by Youden's index, as well as landmark analyses to determine the association between biomarkers and RF, were performed. Of the 6 markers, Stimulation-2 (ST2), WAP 4-disulfide core domain protein 2 (WFDC2), interleukin-6 (IL-6), and tumor necrosis factor receptor 1 (TNFR1), measured at day 14 post-HCT, had the most significant association with an increased risk for RF in the training cohort (ST2: hazard ratio [HR], 4.5, P = .004; WFDC2: HR, 4.2, P = .010; IL-6: HR, 6.9, P < .001; and TFNR1: HR, 6.1, P < .001) and in the validation cohort (ST2: HR, 23.2, P = .013; WFDC2: HR, 18.2, P = .019; IL-6: HR, 12.2, P = .014; and TFNR1: HR, 16.1, P = .001) after adjusting for the conditioning regimen. Using cause-specific landmark analyses, including days 7 and 14, high plasma levels of ST2, WFDC2, IL-6, and TNFR1 were associated with an increased HR for RF in the training and validation cohorts. These biomarkers were also predictive of mortality from RF. ST2, WFDC2, IL-6 and TNFR1 levels measured early posttransplantation improve risk stratification for RF and its related mortality., (© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Vincristine is a core chemotherapeutic drug administered to pediatric acute lymphoblastic leukemia patients. Despite its efficacy in treating leukemia, it can lead to severe peripheral neuropathy in a subgroup of the patients. Peripheral neuropathy is a debilitating and painful side-effect that can severely impact an individual's quality of life. Currently, there are no established predictors of peripheral neuropathy incidence during the early stage of chemotherapeutic treatment. As a result, patients who are not susceptible to peripheral neuropathy may receive sub-therapeutic treatment due to an empirical upper cap on the dose, while others may experience severe neuropathy at the same dose. Contrary to previous genomics based approaches, we employed a metabolomics approach to identify small sets of metabolites that can be used to predict a patient's susceptibility to peripheral neuropathy at different time points during the treatment. Using those identified metabolites, we developed a novel strategy to predict peripheral neuropathy and subsequently adjust the vincristine dose accordingly. In accordance with this novel strategy, we created a free user-friendly tool, VIPNp, for physicians to easily implement our prediction strategy. Our results showed that focusing on metabolites, which encompasses both genotypic and phenotypic variations, can enable early prediction of peripheral neuropathy in pediatric leukemia patients.

Assessment of prognostic biomarkers of nonrelapse mortality (NRM) after allogeneic hematopoietic cell transplantation (HCT) in the pediatric age group is lacking. To address this need, we conducted a prospective cohort study with 415 patients at 6 centers: 170 were children age 10 years or younger and 245 were patients older than age 10 years (both children and adults were accrued from 2013 to 2018). The following 4 plasma biomarkers were assessed pre-HCT and at days +7, +14, and +21 post-HCT: stimulation-2 (ST2), tumor necrosis factor receptor 1 (TNFR1), regenerating islet-derived protein 3α (REG3α), and interleukin-6 (IL-6). We performed landmark analyses for NRM, dichotomizing the cohort at age 10 years or younger and using each biomarker median as a cutoff for high- and low-risk groups. Post-HCT biomarker analysis showed that ST2 (>26 ng/mL), TNFR1 (>3441 pg/mL), and REG3α (>25 ng/mL) are associated with NRM in children age 10 years or younger (ST2: hazard ratio [HR], 9.13; 95% confidence interval [CI], 2.74-30.38; P = .0003; TNFR1: HR, 4.29; 95% CI, 1.48-12.48; P = .0073; REG3α: HR, 7.28; 95% CI, 2.05-25.93; P = .0022); and in children and adults older than age 10 years (ST2: HR, 2.60; 95% CI, 1.15-5.86; P = .021; TNFR1: HR, 2.09; 95% CI, 0.96-4.58; P = .06; and REG3α: HR, 2.57; 95% CI, 1.19-5.55; P = .016). When pre-HCT biomarkers were included, only ST2 remained significant in both cohorts. After adjustment for significant covariates (race/ethnicity, malignant disease, graft, and graft-versus-host-disease prophylaxis), ST2 remained associated with NRM only in recipients age 10 years or younger (HR, 4.82; 95% CI, 1.89-14.66; P = .0056). Assays of ST2, TNFR1, and REG3α in the first 3 weeks after HCT have prognostic value for NRM in both children and adults. The presence of ST2 before HCT is a prognostic biomarker for NRM in children age 10 years or younger allowing for additional stratification. This trial was registered at www.clinicaltrials.gov as #NCT02194439., (© 2020 by The American Society of Hematology.)

Rationale: Pulmonary complications after hematopoietic stem cell transplant (SCT) are associated with increased mortality. Genetic markers for those at risk for pulmonary impairment post-SCT have not been widely investigated., Methods: Forty-nine patients were retrospectively selected from a single institution's biorepository with linked clinical data. All subjects performed pre-SCT PFTs. Genotyping was conducted using the Infinium Exome-24 BeadChip. Four single nucleotide polymorphisms (SNPs) were selected (rs1800871, rs1695, rs1800629, rs12477314) and evaluated for association with PFT parameters as change over time from baseline. Associations between SNPs and PFT parameters were assessed and adjusted for the following confounding variables: age, gender, and race., Results: Using the recessive genetic model, patients with one or two minor alleles for the glutathione S-transferase P1 (GSTP1) SNP rs1695 had a lower decline in FEV 1 and FEF 25-75 at 1-year post-SCT compared to patients who were homozygous for the ancestral allele (adjusted P-values <0.01 and 0.02, respectively). No other SNPs were significantly associated with other PFT parameters., Conclusions: Our findings suggest that GSTP1 genotype may be associated with lung function during the first year post-SCT. Identifying and investigating genes that predispose patients to pulmonary complications after SCT may allow for more personalized patient management based on pre-emptive genetic testing. The glutathione S-transferase gene merits further investigation., (© 2017 Wiley Periodicals, Inc.)

Airway epithelial CD55 down-regulation occurs in several hypoxia-associated pulmonary diseases, but the mechanism is unknown. Using in vivo and in vitro assays of pharmacologic inhibition and gene silencing, the current study investigated the role of hypoxia-inducible factor (HIF)-1α in regulating airway epithelial CD55 expression. Hypoxia down-regulated CD55 expression on small-airway epithelial cells in vitro, and in murine lungs in vivo; the latter was associated with local complement activation. Treatment with pharmacologic inhibition or silencing of HIF-1α during hypoxia-recovered CD55 expression in small-airway epithelial cells. HIF-1α overexpression or blockade, in vitro or in vivo, down-regulated CD55 expression. Collectively, these data show a key role for HIF-1α in regulating the expression of CD55 on airway epithelium.

Problem: To add to diversity in our state biobank, we explored the feasibility of collecting genetic material from adolescents with oppositional defiant disorder (ODD) and/or conduct disorder (CD) and their family members. We also preliminarily explored genetic factors associated with ODD and/or CD by comparing participant data to 1000 Genome Project data on minor allele frequencies., Methods: Adolescents with ODD and/or CD and family members provided saliva samples for genetic testing. We evaluated five single-nucleotide polymorphisms (SNPs), respectively, in the dopamine receptor subtype D2, dopamine receptor subtype D3, dopamine beta-hydroxylase, dopamine transporter gene SLC6A3, and alpha-2-adrenergic receptor genes. Fisher's exact tests were used to examine differences in minor allele frequencies for each SNP., Findings: Thirty-one viable samples were genotyped from 15 affected adolescents and 16 unaffected family members; the 60% consent rate reflected high feasibility. Compared with the 1000 Genome Project frequencies, affected adolescents had higher frequencies of the genetic variant in the dopamine receptor subtype D2 (p = .05) and dopamine beta-hydroxylase (p = 0.03), but not of the other three SNPs examined., Conclusions: Collecting genetic materials from an ethnically diverse sample of affected adolescents and their families is feasible. We offer practical suggestions to strengthen the integrity of future research studies., (© 2016 Wiley Periodicals, Inc.)

Purpose: The Precision Medicine Initiative (PMI) goal of ushering in a new and more effective era of health care that benefits all Americans requires two critical and interdependent components: a cohort assembly of 1 million or more Americans who reflect the diversity of the United States of America and an interdisciplinary workforce that includes nursing. The purpose of this article is to provide an example of nursing involvement in PM, specifically as related to gathering biospecimens (saliva) from vulnerable, understudied adolescents with disruptive behavior disorders and their family members., Source(s): First, we provide a brief description of important concepts related to PM as well as current roles of nurses in PM. Then, we share lessons learned from our feasibility study aimed at increasing the diversity of our statewide cohort assembly that has provided biospecimens for the Indiana Biobank., Conclusion: Nurses can definitely contribute to biobanks in support of the PMI. This article is a call to action for nurses to take their rightful place in PM., (© 2016 Wiley Periodicals, Inc.)

Reliable, noninvasive methods for diagnosing and prognosing sinusoidal obstruction syndrome (SOS) early after hematopoietic cell transplantation (HCT) are needed. We used a quantitative mass spectrometry-based proteomics approach to identify candidate biomarkers of SOS by comparing plasma pooled from 20 patients with and 20 patients without SOS. Of 494 proteins quantified, we selected 6 proteins (L-Ficolin, vascular cell adhesion molecule-1 [VCAM1], tissue inhibitor of metalloproteinase-1, von Willebrand factor, intercellular adhesion molecule-1, and CD97) based on a differential heavy/light isotope ratio of at least 2 fold, information from the literature, and immunoassay availability. Next, we evaluated the diagnostic potential of these 6 proteins and 5 selected from the literature (suppression of tumorigenicity-2 [ST2], angiopoietin-2 (ANG2), hyaluronic acid [HA], thrombomodulin, and plasminogen activator inhibitor-1) in samples from 80 patients. The results demonstrate that together ST2, ANG2, L-Ficolin, HA, and VCAM1 compose a biomarker panel for diagnosis of SOS. L-Ficolin, HA, and VCAM1 also stratified patients at risk for SOS as early as the day of HCT. Prognostic Bayesian modeling for SOS onset based on L-Ficolin, HA, and VCAM1 levels on the day of HCT and clinical characteristics showed >80% correct prognosis of SOS onset. These biomarkers may provide opportunities for preemptive intervention to minimize SOS incidence and/or severity., (Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Radiation during childhood cancer treatment increases the propensity to atherosclerotic cardiovascular disease among adult survivors of childhood cancer. This is thought to be mediated through the damage to the underlying vascular endothelium. Endothelial progenitor cells (EPCs) involved in vascular endothelial repair after its damage may be affected by radiation therapy but have never been investigated in adult survivors of childhood cancer. In this pilot study, utilizing multi-parametric flowcytometry, endothelial colony forming cells (ECFCs), which are the bonafide EPCs, and circulating endothelial cells (CECs), which are not EPCs, were compared between adult survivors of childhood cancer with or without radiation exposure. In addition, their associations with blood-pressure, physical activity and diet were examined. Survivors who received radiotherapy had lower ECFCs and CECs (p<0.05) compared to those without it. Significant positive correlations included physical activity with ECFCs and diet with CECs, while blood-pressure negatively correlated with ECFCs. Further evaluation is needed to examine the effect of radiation and modifiable risk factors on ECFCs and CECs. The preliminary findings from this study suggest evidence of the role of ECFCs as biomarkers of vascular injury following treatment for childhood cancer that may help in early identification of survivors at risk for cardiovascular disease.

Vincristine, a critical component of combination chemotherapy treatment for pediatric acute lymphoblastic leukemia (ALL), can lead to vincristine-induced peripheral neuropathy (VIPN). Longitudinal VIPN assessments were obtained over 12 months from newly diagnosed children with ALL (N = 128) aged 1-18 years who received vincristine at one of four academic children's hospitals. VIPN assessments were obtained using the Total Neuropathy Score-Pediatric Vincristine (TNS©-PV), National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE©), Balis© grading scale, and Pediatric Neuropathic Pain Scale©-Five (PNPS©-5). Of children who provided a full TNS©-PV score, 85/109 (78%) developed VIPN (TNS©-PV ≥4). Mean TNS©-PV, grading scale, and pain scores were low. CTCAE©-derived grades 3 and 4 sensory and motor VIPN occurred in 1.6%/0%, and 1.9%/0% of subjects, respectively. VIPN did not resolve in months 8-12 despite decreasing dose density. VIPN was worse in older children. Partition cluster analysis revealed 2-3 patient clusters; one cluster (n = 14) experienced severe VIPN. In this population, VIPN occurs more commonly than previous research suggests, persists throughout the first year of treatment, and can be severe., (© 2015 Peripheral Nerve Society.)

Biomarkers have the potential to improve diagnosis and prognosis, facilitate-targeted treatment, and reduce health care costs. Thus, there is great hope that biomarkers will be integrated in all clinical decisions in the near future. A decade ago, the biomarker field was launched with great enthusiasm because MS revealed that blood contains a rich library of candidate biomarkers. However, biomarker research has not yet delivered on its promise due to several limitations: (i) improper sample handling and tracking as well as limited sample availability in the pediatric population, (ii) omission of appropriate controls in original study designs, (iii) lability and low abundance of interesting biomarkers in blood, and (iv) the inability to mechanistically tie biomarker presence to disease biology. These limitations as well as successful strategies to overcome them are discussed in this review. Several advances in biomarker discovery and validation have been made in hematopoietic stem cell transplantation, the current most effective tumor immunotherapy, and these could serve as examples for other conditions. This review provides fresh optimism that biomarkers clinically relevant in pediatrics are closer to being realized based on: (i) a uniform protocol for low-volume blood collection and preservation, (ii) inclusion of well-controlled independent cohorts, (iii) novel technologies and instrumentation with low analytical sensitivity, and (iv) integrated animal models for exploring potential biomarkers and targeted therapies., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: Vincristine-induced peripheral neuropathy (VIPN) is difficult to quantify in children., Objective: The study objective was to examine the reliability, validity, and clinical feasibility of several VIPN measures for use in children with acute lymphoblastic leukemia., Interventions/methods: Children (n = 65) aged 1 to 18 years receiving vincristine at 4 academic centers participated in the study. Baseline and pre-vincristine administration VIPN assessments were obtained using the Total Neuropathy Score-Pediatric Vincristine (TNS©-PV), the National Cancer Institute Common Terminology Criteria for Adverse Events, the Balis grading scale, and the FACES Pain Scale. The TNS-PV scores (n = 806) were obtained over 15 weeks. Blood was obtained at several time points to quantify pharmacokinetic parameters., Results: Cronbach's α for a reduced TNS-PV scale was .84. The TNS-PV scores correlated with cumulative vincristine dosage (r = 0.53, P = 0.01), pharmacokinetic parameters (r = 0.41, P = 0.05), and grading scale scores (r range = 0.46-0.52, P = .01). FACES scores correlated with the TNS-PV neuropathic pain item (r = 0.48; P = .01) and were attainable in all ages. A 2-item V-Rex score (vibration and reflex items) was the most responsive to change (effect size = 0.65, P < 0.001). The TNS-PV scores were attainable in 95% of children 6 years or older., Conclusions: The TNS-PV is reliable and valid for measuring VIPN. It is sensitive to change over time (15 weeks) and feasible for use in children 6 years or older., Implications for Practice: The TNS-PV may be a useful tool for assessing vincristine toxicity in children with acute lymphoblastic leukemia.

Mitosis is controlled by a network of kinases and phosphatases. We screened a library of small interfering RNAs against a genome-wide set of phosphatases to comprehensively evaluate the role of human phosphatases in mitosis. We found four candidate spindle checkpoint phosphatases, including the tumor suppressor CDKN3. We show that CDKN3 is essential for normal mitosis and G1/S transition. We demonstrate that subcellular localization of CDKN3 changes throughout the cell cycle. We show that CDKN3 dephosphorylates threonine-161 of CDC2 during mitotic exit and we visualize CDC2(pThr-161) at kinetochores and centrosomes in early mitosis. We performed a phosphokinome-wide mass spectrometry screen to find effectors of the CDKN3-CDC2 signaling axis. We found that one of the identified downstream phosphotargets, CKβ phosphorylated at serine 209, localizes to mitotic centrosomes and controls the spindle checkpoint. Finally, we show that CDKN3 protein is down-regulated in brain tumors. Our findings indicate that CDKN3 controls mitosis through the CDC2 signaling axis. These results have implications for targeted anticancer therapeutics.

Background: Cisplatin is an effective chemotherapy agent against several pediatric malignancies. One of its side effects is irreversible sensorineural hearing damage that is highly variable with a reported incidence of 22-70%. The aim of this study was to evaluate the incidence and identify clinical predictors of cisplatin-related ototoxicity., Procedures: We performed a retrospective chart review of 102 pediatric patients who had completed cisplatin therapy for osteosarcoma, neuroblastoma, hepatoblastoma, or germ cell tumor. Patients were diagnosed at Riley Hospital for Children between January 1995 and June 2008, were less than 18 years old at diagnosis, and had normal hearing prior to therapy. Audiograms were scored using the Brock scale (0-4), a validated grading system for cisplatin-related hearing loss., Results: Forty-two percent of the patients experienced hearing loss and 28% had moderate to severe ototoxicity (Brock score ≥2). Males were at significantly greater risk for developing hearing loss than were females (P = 0.005, OR 4.812). Age at cancer diagnosis was inversely related to severity of ototoxicity. Patients who suffered Brock grade 3 ototoxicity had a mean age of 4.5 years versus 11.5 years and 7.2 years for grades 1 and 2, respectively (P = 0.02). Cumulative cisplatin dose was also identified as a risk factor for development of ototoxicity (P = 0.03)., Conclusions: Gender and cumulative dose are important clinical biomarkers of cisplatin ototoxicity. Severity of ototoxicity may be inversely related to age at time of exposure, with very young patients exhibiting higher grades of hearing loss following cisplatin therapy., (Copyright © 2012 Wiley Periodicals, Inc.)

Background: Dactinomycin (AMD) and vincristine (VCR) have been used for the treatment of childhood cancer over the past 40 years but evidence-based dosing guidance is lacking., Methods: Patient AMD and VCR dose and drug-related adverse event (AE) information from four rhabdomyosarcoma (RMS) and two Wilms tumor (WT) studies were assembled. Statistical modeling was used to account for differences in AE data collection across studies, develop rate models for grade 3/4 CTCAE v3 hepatic- (AMD) and neuro- (VCR) toxicity, assess variation in toxicity rates over age and other factors, and predict toxicity risk under current dosing guidelines., Results: For the same dose/body size, AMD toxicity rates were higher in patients <1 year than older patients and VCR toxicity rates increased with age. The statistical model provided estimates for AMD and VCR toxicity risk under current dosing schedules and indicated that patients of smaller body size were at lower risk of VCR toxicity than larger patients of the same age. The rate of AMD toxicity was highest early in treatment and was lower in patients who tolerated initial AMD without toxicity., Conclusion: The observed decrease in AMD toxicity rate with cumulative dose may indicate sensitivity in a subgroup of patients while the observed increase in VCR toxicity risk with age may indicate changing sensitivity to VCR. Current dosing practices result in a fairly uniform toxicity profile within age group. However, PK/PD studies should be done to provide further provide further information on best dosing guidelines., (Copyright © 2010 Wiley-Liss, Inc.)

Purpose: We studied the relationship between doxorubicin pharmacokinetics and body composition in children with cancer., Patients and Methods: Children between 1 and 21 years of age, receiving doxorubicin as an infusion of any duration <24 h on either a 1-day or 2-day schedule were eligible if they had no significant abnormality of liver function tests, their dose of doxorubicin was not based on ideal body weight or otherwise "capped," and they weighed > or =12 kg. Body composition was measured by dual-energy X-ray absorptiometry. Doxorubicin and doxorubicinol concentration in plasma were measured by high pressure liquid chromatography. NONMEM was used to perform pharmacokinetic model fitting and S-PLUS was used to perform a post hoc analysis to examine the effect of body composition on pharmacokinetic parameters., Results: Twenty-two subjects (16 male; 10 Hispanic, 10 Caucasian, 2 Asian) completed the study. The median age was 15.0 years (range 3.3-21.5), median weight was 51.5 kg (range 12.4-80), median BMI was 19.7 (range 13.2-30.0), and median body fat was 25% (range 15-36). The population mean clearance of doxorubicin was 420 ml/min/m(2). Doxorubicinol but not doxorubicin clearance was lower in patients with body fat greater than 30%., Conclusions: Doxorubicinol clearance is decreased in children with >30% body fat. This finding is potentially important clinically, because doxorubicinol may contribute significantly to cardiac toxicity after doxorubicin administration. Further study of the body composition on doxorubicin and doxorubicinol pharmacokinetics and on clinical outcomes is warranted.

Purpose: A phase I study of intrathecal (IT) gemcitabine was performed to define a safe dose and characterize the toxicity profile and CSF pharmacokinetics of gemcitabine and its major metabolite 2',2'-difluoro-deoxyuridine (dFdU) in patients 3 years of age and older with neoplastic meningitis., Experimental Design: Gemcitabine was administered via Ommaya reservoir or lumbar puncture at three dose levels: 5 mg weekly, 5 mg twice-weekly, and 10 mg twice-weekly using a standard phase I dose escalation design. Serial CSF samples were obtained for pharmacokinetic studies in seven patients with Ommaya reservoirs. Serial blood samples for pharmacokinetic studies were also obtained from three patients., Results: Ten patients were enrolled in this study. Significant neurological toxicities occurred in two patients including myelitis in a patient at the 5 mg twice-weekly dose level and somnolence in a patient at the 10 mg twice-weekly dose level. No complete responses were seen; however, three patients had stable disease. Gemcitabine was rapidly eliminated from the CSF with a terminal half-life of 61 +/- 50 min. No gemcitabine or dFdU was detected in plasma., Conclusions: IT gemcitabine was associated with significant neurotoxicity; therefore, its further development for IT use is not recommended.

Purpose: SU5416 is a small, lipophilic synthetic molecule that selectively inhibits the tyrosine kinase activity of the VEGF receptor Flk-1/KDR. The role of this agent in brain tumors is currently being investigated. Pharmacokinetic studies of SU5416 have been performed in humans; however, there have been no studies of its penetration in the cerebrospinal fluid (CSF). We studied the pharmacokinetics of SU5416 in plasma and CSF after intravenous (i.v.) administration using a nonhuman primate model that is highly predictive of the CSF penetration in humans., Experimental Design: SU5416 (85 mg/m(2), about 3.8 mg/kg) was administered i.v. over 20 min to four nonhuman primates. Serial plasma and CSF samples were obtained prior to, during, and after completion of the infusion for determination of SU5416 concentrations. SU5416 was measured in plasma and CSF using high-performance liquid chromatography (HPLC). Concentration-versus-time data were modeled using model-independent and model-dependent methods., Results: Peak plasma concentrations ranged from 6.3 to 14.5 microM and the mean plasma AUC was 620+/-180 microM.min. Disappearance of SU5416 from the plasma was best described by a one-compartment model with a half-life of 39+/-2.9 min. The volume of distribution was 36+/-11 l/m(2) and the clearance was 0.62+/-0.2 l/min per m(2). SU4516 was not quantifiable in the CSF., Conclusions: There is minimal penetration of SU5416 into the CSF after i.v. administration. The very low CNS exposure to SU5416 after i.v. dosing suggests that this agent is not optimal for the treatment of leptomeningeal tumors.

Infectious complications including pneumonia remain a major obstacle to survival in children with cancer. Pulmonary infections usually arise from aspiration of pathogens from the upper airways or from hematogenous spread. Pathogens include bacteria, Pneumocystis carinii, viruses, and fungi. In this article, we review in detail the pathogenic basis, evaluation, and management of pneumonia in the immunocompromised pediatric cancer patient.