Lack of benefit from premedication for pegylated asparaginase during pediatric acute lymphoblastic leukemia/lymphoma therapy: A side-by-side comparison

BACKGROUND

Pegylated l-asparaginase (PEG) is integral to treatment regimens for acute lymphoblastic leukemia (ALL) and lymphoma. Hypersensitivity reactions (HSRs) to PEG are common and can preclude continued administration. Data supporting recommendations for universal premedication (UPM) prior to PEG infusion to reduce incidence of HSRs are limited; UPM has become common practice.

PROCEDURES

Two free-standing children's hospitals independently implemented UPM prior to PEG infusions in 2016 and 2019, respectively. In a side-by-side retrospective analysis, incidence and severity of HSRs were analyzed pre- and postimplementation of UPM in youth ≥1 years old treated with frontline PEG-containing ALL regimens (2015-2018, 2016-2020). All HSRs were centrally reviewed within each institution to confirm and grade the HSR (Common Terminology Criteria for Adverse Events, v5). Planned analyses of subsets at potentially greater risk for HSRs included intensive PEG regimens (≥5 doses), adolescent and young adults (AYA), Hispanic/Latinx ethnicity, and obesity.

RESULTS

In 410 patients (by institution, n = 282 and n = 128), the overall incidence of Grade ≥ 3 HSRs was 20% (56 out of 282) and 18% (23 out of 128), respectively. No difference in incidence of Grade ≥ 3 HSRs in patients with versus without UPM was found at either institution (23 vs. 19%, p = .487 and 19 vs. 17%, p = .845). UPM also did not reduce the severity of HSRs, nor influence HSR risk within any patient subset.

CONCLUSIONS

UPM prior to PEG infusion did not alter incidence or severity of HSRs at either institution. HSR remains a common complication of PEG therapy, impacting the patient experience. Alternative strategies to reduce HSRs are urgently required.

Intravenous N-Acetylcysteine to Prevent Cisplatin-Induced Hearing Loss in Children: A Nonrandomized Controlled Phase I Trial

PURPOSE

Cisplatin-induced hearing loss (CIHL) is common and permanent. As compared with earlier otoprotectants, we hypothesized N-acetylcysteine (NAC) offers potential for stronger otoprotection through stimulation of glutathione (GSH) production. This study tested the optimal dose, safety, and efficacy of NAC to prevent CIHL.

PATIENTS AND METHODS

In this nonrandomized, controlled phase Ia/Ib trial, children and adolescents newly diagnosed with nonmetastatic, cisplatin-treated tumors received NAC intravenously 4 hours post-cisplatin. The trial performed dose-escalation across three dose levels to establish a safe dose that exceeded the targeted peak serum NAC concentration of 1.5 mmol/L (as identified from preclinical models). Patients with metastatic disease or who were otherwise ineligible were enrolled in an observation-only/control arm. To evaluate efficacy, serial age-appropriate audiology assessments were performed. Integrated biology examined genes involved in GSH metabolism and post-NAC GSH concentrations.

RESULTS

Of 52 patients enrolled, 24 received NAC and 28 were in the control arm. The maximum tolerated dose was not reached; analysis of peak NAC concentration identified 450 mg/kg as the recommended phase II dose (RP2D). Infusion-related reactions were common. No severe adverse events occurred. Compared with the control arm, NAC decreased likelihood of CIHL at the end of cisplatin therapy [OR, 0.13; 95% confidence interval (CI), 0.021-0.847; P = 0.033] and recommendations for hearing intervention at end of study (OR, 0.082; 95% CI, 0.011-0.60; P = 0.014). NAC increased GSH; GSTP1 influenced risk for CIHL and NAC otoprotection.

CONCLUSIONS

NAC was safe at the RP2D, with strong evidence for efficacy to prevent CIHL, warranting further development as a next-generation otoprotectant.

COVID-19 outcomes in children, adolescents and young adults with cancer

Pediatric oncology patients are at risk for poor outcomes with respiratory viral infections. Outcome data for COVID‐19 in children and young adults with cancer are needed; data are sparse for obese/overweight and adolescent and young adult subgroups. We conducted a single center cohort study of COVID‐19 outcomes in patients younger than 25 years with cancer. Candidate hospitalization risk factors were analyzed via univariable and multivariable analyses. Eighty‐seven patients with cancer and COVID‐19 were identified. Most were Hispanic/Latinx (n = 63, 72%). Forty‐two (48%) were overweight/obese. Anticancer therapy included chemotherapy only (n = 64, 74%), chimeric antigen receptor T‐cells (CAR‐T, n = 7), hematopoietic stem cell transplantation (HSCT, n = 12), or CAR‐T and HSCT (n = 4). There was no COVID‐19 related mortality. Twenty‐six patients (30%) required COVID‐19 related hospitalization; 4 required multiple hospitalizations. Nine (10%) had severe/critical infection; 6 needed intensive care. COVID‐19 resulted in anticancer therapy delays in 22 (34%) of 64 patients on active therapy (median delay = 14 days). Factors associated with hospitalization included steroids within 2 weeks prior to infection, lymphopenia, previous significant non‐COVID infection, and low COVID‐19 PCR cycle threshold value. CAR‐T recipients with B‐cell aplasia tended to have severe/critical infection (3 of 7 patients). A COVID‐19 antibody response was detected in 14 of 32 patients (44%). A substantial proportion of COVID‐19 infected children and young adults with cancer require inpatient management; morbidity may be high in B‐cell immunodeficiency. However, a majority of patients can be taken through chemotherapy without prolonged therapy delays. Viral load is a potential outcome predictor in COVID‐19 in pediatric cancer.

Association of body mass index with toxicity and survival in pediatric patients treated with cisplatin-containing regimens

Malnutrition is associated with treatment-related toxicities (TRT) in adults with solid tumors and in children with leukemia. Few studies have assessed whether malnutrition in pediatric patients treated for solid tumors impacts risk for TRT, relapse, and/or survival. To address this knowledge gap, this retrospective study evaluated the association between body mass index (BMI) at diagnosis, and imputed BMI during therapy, on the prevalence of TRT, specific toxicities, relapse, and survival in pediatric patients with solid tumors treated with cisplatin-containing regimens. Kaplan-Meier curves and regression models evaluated the association between patient-specific characteristics (including BMI) and TRT, relapse, and survival. The cohort included 221 patients, of whom 22% were malnourished at diagnosis (10% were underweight and 12% were obese). Most patients (60%) experienced at least one severe TRT, and 30% developed more than one severe TRT. Most patients with obesity at diagnosis remained obese during therapy (62%). In multivariable analysis, obesity at diagnosis was significantly associated with a more than threefold greater risk for developing severe TRT (p = 0.037), specifically for acute or chronic kidney injury (p = 0.014). Obesity at diagnosis and adolescent and young adult age (≥15 years at diagnosis) were associated with worse event-free survival (hazard ratio [HR] 2.32, p = 0.024 and HR 2.28, p = 0.010, respectively) and overall survival (HR 3.69, p = 0.006 and HR 2.6, p = 0.012, respectively). Obese and older patients therefore constitute populations at risk for poorer outcomes. Prospective studies are warranted to gain further insight into the mechanism and role of obesity and adolescence in developing TRT and/or treatment failure.

Prevalence and risk factors for cisplatin-induced hearing loss in children, adolescents, and young adults: a multi-institutional North American cohort study

BACKGROUND

Cisplatin is used to treat a wide range of childhood cancers and cisplatin-induced hearing loss (CIHL) is a common and debilitating toxicity. We aimed to address persistent knowledge gaps in CIHL by establishing benchmarks for the prevalence of and risk factors for CIHL.

METHODS

In this multi-institutional cohort study, children (age 0-14 years), adolescents, and young adults (age 15-39 years) diagnosed with a cisplatin-treated tumour from paediatric cancer centres, who had available cisplatin dosing information, and primary audiology data for central review from consortia located in Canada and the USA were eligible for inclusion. Audiology was centrally reviewed and CIHL graded using the consensus International Society of Pediatric Oncology (SIOP) Boston Ototoxicity Scale. We assessed the prevalence of moderate or severe CIHL (SIOP grade ≥2) at latest follow-up and end of therapy, in each demographic, diagnosis, and treatment group and their relative contributions to risk for CIHL. Secondary endpoints explored associations of cisplatin dose reductions and CIHL with survival. We also examined whether cisplatin dose reductions and CIHL were associated with survival outcomes.

FINDINGS

We included 1481 patients who received cisplatin. Of the 1414 (95·5%) participants who had audiometry at latest follow-up (mean 3·9 years [SD 4·2] since diagnosis), 620 (43·8%) patients developed moderate or severe CIHL. The highest prevalence of CIHL was seen in the youngest patients (aged <5 years; 360 [59·4%] of 606 patients) and those with a CNS tumour (221 [50·9%] of 434 patients), hepatoblastoma (110 [65·9%] of 167 patients), or neuroblastoma (154 [62·1%] of 248 patients). After accounting for cumulative cisplatin dose, higher fractionated doses were associated with risk for CIHL (for each 10mg/m2 increase per day, adjusted odds ratio [aOR] 1·15 [95% CI 1·07-1·25]; for each 50 mg/m2 increase per cycle aOR 2·16 [1·37-3·51]). Vincristine exposure was newly identified as a risk factor for CIHL (aOR 3·55 [2·19-5·84]). Dose reductions and moderate or severe CIHL were not significantly associated with survival differences.

INTERPRETATION

Using this large, multicentre cohort, benchmarks were established for the prevalence of CIHL in patients treated with cisplatin. Variations in cisplatin dosing confer additive risk for developing CIHL and warrant investigation as a potential approach to decrease the burden of therapy.

FUNDING

US National Institutes of Health and National Institute on Deafness and Other Communication Disorders, US National Institutes of Health and National Cancer institute, St Baldrick's Foundation, Genome Canada, Genome British Columbia, Canadian Institutes of Health Research, the Canada Foundation for Innovation, University of British Columbia, British Columbia Children's Hospital Research Institute, British Columbia Provincial Health Services Authority, Health Canada, and C17 Research Network.

Intra-individual Pharmacokinetic Variability of Intravenous Busulfan in Hematopoietic Stem Cell-Transplanted Children

BACKGROUND

Busulfan therapeutic drug monitoring (TDM) is necessary to better achieve the target exposure in children before hematopoietic stem cell transplantation (HSCT). However, TDM-based dosing may be challenging if intra-individual pharmacokinetic variability (also denoted inter-occasion variability [IOV]) occurs during therapy.

OBJECTIVES

The objectives of this study were to describe and quantify busulfan IOV in children, and to investigate its potential determinants.

METHODS

We performed a new analysis of published data from children who received intravenous busulfan over 4 days before HSCT. We calculated individual pharmacokinetic parameters on each day of therapy using a published population pharmacokinetic model of busulfan and analyzed their changes. Population estimation of IOV was also performed with non-linear mixed effects (NLME) modeling. Potential predictors of significant decrease in busulfan clearance (CL) were assessed by using machine learning approaches.

RESULTS

IOV could be assessed in 136 children. Between day (D) 1 and D2, most patients (80%) experienced a decrease in busulfan CL, with a median change of - 7.9%. However, both large decreases (minimum, -  48.5%) and increases in CL (maximum, + 44%) were observed. Over D1-D3 of therapy, mean CL significantly decreased (-  15%), with a decrease of ≥ 20% in 22% of patients. Some patients also showed unstable CL from day to day. NLME modeling of IOV provided a coefficient of variation of 10.6% and 13.1% for volume of distribution (V_d) and CL, respectively. Some determinants of significant decreases in busulfan CL were identified, but predictive performance of the models was limited.

CONCLUSIONS

Significant busulfan intra-individual variability may occur in children who receive a HSCT and is hardly predictable. The main risk is busulfan overexposure. Performing TDM repeatedly over therapy appears to be the best way to accurately estimate busulfan exposure and perform precision dosing.

Improving the Timeliness of Chemotherapy Administration in the Bone Marrow Transplant Unit

Patients undergoing hematopoietic stem cell transplantation (HSCT) are often admitted to the hospital the day they are due to begin their conditioning regimen. Timely initiation of chemotherapy during regular work hours is important for patient safety, because during the night shift fewer physicians and pharmacists are available for urgent or unexpected matters. A review of the data at our institution from October 2017 to August 2018 showed that approximately one-third of our chemotherapy was started during the night shift (after 19:00), and the average time from admission to start of chemotherapy was over 8 hours. There are currently no well-defined benchmarks for timeliness of chemotherapy initiation. The aim of this quality improvement initiative was to increase the percentage of patients who start chemotherapy in the bone marrow transplant unit before 19:00 from 65% to >80% by March 31, 2019. We identified barriers to timely initiation of chemotherapy through process mapping and analysis of failures. The primary barriers were late admissions (after 12:00 pm) and time from admission to preparation of chemotherapy. We addressed mechanisms to mitigate these barriers through Plan-Do-Study-Act testing. Interventions included providing families specific admission times and their rationales and process for notifying pharmacy of admissions immediately on arrival. We used standardized control charts to measure the impact of the interventions on change. We also monitored medication errors before and during the intervention. From September 2018 to March 2019 the percentage of patients who started preparative chemotherapy before 19:00 increased from 65% to 85%, the percentage of patients who were admitted after 12:00 remained similar before (31%) and after the interventions (33%), and the average time from admission to start of chemotherapy decreased from 8.6 hours (513 minutes) to 6.4 hours (382 minutes). Medication errors were similar before (n = 50) and after the interventions (n = 43). Using standardized processes, we demonstrated a substantial decrease in the percentage of HSCT patients starting their preparative regimen after 19:00 without a concurrent increase in errors. We believe these interventions and measurements can be used in all transplant centers and have the potential to influence patient safety and outcomes.

Repurposing Cytarabine for Treating Primary Effusion Lymphoma by Targeting Kaposi's Sarcoma-Associated Herpesvirus Latent and Lytic Replications

Oncogenic Kaposi's sarcoma-associated herpesvirus (KSHV) is etiologically linked to primary effusion lymphoma (PEL), an aggressive and nontreatable malignancy commonly found in AIDS patients. In this study, we performed a high-throughput screening of 3,731 characterized compounds and identified cytarabine, approved by the FDA for treating numerous types of cancer, as a potent inhibitor of KSHV-induced PEL. We showed the high efficacy of cytarabine in the growth inhibition of various PEL cells by inducing cell cycle arrest and apoptosis. Cytarabine inhibited host DNA and RNA syntheses and therefore induced cellular cytotoxicity. Furthermore, cytarabine inhibited viral DNA and RNA syntheses and induced the rapid degradation of KSHV major latent protein LANA (latency-associated nuclear antigen), leading to the suppression of KSHV latent replication. Importantly, cytarabine effectively inhibited active KSHV replication and virion production in PEL cells. Finally, cytarabine treatments not only effectively inhibited the initiation and progression of PEL tumors but also induced regression of grown PEL tumors in a xenograft mouse model. Altogether, our study has identified cytarabine as a novel therapeutic agent for treating PEL as well as eliminating KSHV persistent infection.IMPORTANCE Primary effusion lymphoma is an aggressive malignancy caused by Kaposi's sarcoma-associated herpesvirus. The outcome of primary effusion lymphoma is dismal without specific treatment. Through a high-throughput screening of characterized compounds, we identified an FDA-approved compound, cytarabine, as a potent inhibitor of primary effusion lymphoma. We showed that cytarabine induced regression of PEL tumors in a xenograft mouse model. Cytarabine inhibited host and viral DNA and RNA syntheses, resulting in the induction of cytotoxicity. Of interest, cytarabine induced the degradation of KSHV major latent protein LANA, hence suppressing KSHV latent replication, which is required for PEL cell survival. Furthermore, cytarabine inhibited KSHV lytic replication program, preventing virion production. Our findings identified cytarabine as a novel therapeutic agent for treating PEL as well as for eliminating KSHV persistent infection. Since cytarabine is already approved by the FDA, it might be an ideal candidate for repurposing for PEL therapy and for further evaluation in advanced clinical trials.

Phase I trial of dasatinib, lenalidomide, and temozolomide in children with relapsed or refractory central nervous system tumors

Single agent studies targeting the tumor microenvironment in central nervous system (CNS) tumors have largely been disappointing. Combination therapies targeting various pathways and cell types may be a more effective strategy. In this phase I study, we evaluated the combination of dasatinib, lenalidomide, and temozolomide in children with relapsed or refractory primary CNS tumors. Patients 1-21 years old with relapsed or refractory CNS tumors were eligible. Starting doses of dasatinib and lenalidomide were 65 mg/m²/dose twice daily and 55 mg/m² once daily, respectively, while temozolomide was constant at 75 mg/m² daily. The study followed a 3 + 3 phase I design, with a 4-week dose-limiting toxicity (DLT) evaluation period. Serial peripheral blood lymphocyte subsets were evaluated in consenting patients. Fifteen patients were enrolled and thirteen were DLT-evaluable. DLTs occurred in 5 patients, including somnolence and confusion (1 patient), hypokalemia (1 patient) and thrombocytopenia (3 patients). The maximum tolerated dose for the combination was dasatinib 65 mg/m² twice daily, lenalidomide 40 mg/m² daily, and temozolomide 75 mg/m² daily, for 21 days followed by 7 days rest in repeating 28-day cycles. Transient increases in natural killer effector cells and cytotoxic T-cells were seen after 1 week of treatment. One out of six response-evaluable patients showed a partial response. The combination was feasible and relatively well tolerated in this heavily pre-treated population. The most common toxicities were hematologic. Preliminary evidence of clinical benefit was seen.

Accurately Achieving Target Busulfan Exposure in Children and Adolescents With Very Limited Sampling and the BestDose Software

BACKGROUND

Busulfan dose adjustment is routinely guided by plasma concentration monitoring using 4-9 blood samples per dose adjustment, but a pharmacometric Bayesian approach could reduce this sample burden.

METHODS

The authors developed a nonparametric population model with Pmetrics. They used it to simulate optimal initial busulfan dosages, and in a blinded manner, they compared dosage adjustments using the model in the BestDose software to dosage adjustments calculated by noncompartmental estimation of area under the time-concentration curve at a national reference laboratory in a cohort of patients not included in model building.

RESULTS

Mean (range) age of the 53 model-building subjects was 7.8 years (0.2-19.0 years) and weight was 26.5 kg (5.6-78.0 kg), similar to nearly 120 validation subjects. There were 16.7 samples (6-26 samples) per subject to build the model. The BestDose cohort was also diverse: 10.2 years (0.25-18 years) and 46.4 kg (5.2-110.9 kg). Mean bias and imprecision of the 1-compartment model-predicted busulfan concentrations were 0.42% and 9.2%, and were similar in the validation cohorts. Initial dosages to achieve average concentrations of 600-900 ng/mL were 1.1 mg/kg (≤12 kg, 67% in the target range) and 1.0 mg/kg (>12 kg, 76% in the target range). Using all 9 concentrations after dose 1 in the Bayesian estimation of dose requirements, the mean (95% confidence interval) bias of BestDose calculations for the third dose was 0.2% (-2.4% to 2.9%, P = 0.85), compared with the standard noncompartmental method based on 9 concentrations. With 1 optimally timed concentration 15 minutes after the infusion (calculated with the authors' novel MMopt algorithm) bias was -9.2% (-16.7% to -1.5%, P = 0.02). With 2 concentrations at 15 minutes and 4 hours bias was only 1.9% (-0.3% to 4.2%, P = 0.08).

CONCLUSIONS

BestDose accurately calculates busulfan intravenous dosage requirements to achieve target plasma exposures in children up to 18 years of age and 110 kg using only 2 blood samples per adjustment compared with 6-9 samples for standard noncompartmental dose calculations.

Efficacy and tolerability of intravenous pentamidine isethionate for Pneumocystis jiroveci prophylaxis in a pediatric oncology population

Cancer therapy routinely requires Pneumocystis jiroveci prophylaxis. In those intolerant of trimethoprim/sulfamethoxazole, aerosolized pentamidine is convenient and effective. Intravenous pentamidine is often substituted in young children but its efficacy remains controversial. In this retrospective study of a large pediatric oncology cohort, we confirm intravenous pentamidine to be effective and well-tolerated as second-line prophylaxis across all ages.

Assessment of knowledge of vincristine toxicities in outpatient pediatric hematology/oncology nurses: An educational intervention

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Background: Vincristine (VCR) is a chemotherapeutic agent with a unique neurological side effect profile and is integral to the treatment of many pediatric hematological and solid malignancies. Side effects requiring VCR dose modification include peripheral neuropathies, intestinal ileus, cranial nerve abnormalities, hyponatremia and seizures. In our institution, orders for weekly VCR are written in advance by oncologists and administered by outpatient nurses independent of a provider physical examination. We sought to increase knowledge of VCR toxicities and improve pre-chemotherapy evaluation skills among outpatient Hematology/Oncology (Hem/Onc) nurses. Methods: A 23-question written quiz was given as a pre-test to 14 outpatient Hem/Onc nurses to assess their fund of knowledge regarding VCR toxicities. An educational intervention was then provided to the cohort as a lecture by a Hem/Onc fellow physician. The lecture was followed by the same quiz given as post-test to the nurses. Individual participant and group scores were tabulated comparing pre and post-test responses to assess improvement in identification and recognition of VCR toxicities. Results: 12/14 nurses demonstrated improvement in their fund of knowledge regarding VCR side effects (mean change in individual scores + 4.7). As a group, mean scores increased from 15.2 to 18/23 (the two-sample paired t-test was significant with a two-tailed p<0.005). Conclusions: An educational intervention significantly improved outpatient Hem/Onc nurses fund of knowledge regarding identification and evaluation of VCR toxicities. Future objectives include follow-up evaluation of retention of knowledge of VCR side effects and incorporating a VCR toxicity checklist into the electronic medical record outpatient nursing note.

Influenza vaccine immunization in a pediatric oncology ambulatory practice

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Backround: Complications from Influenza infection remain an important cause of morbidity and mortality among immunosuppressed children and adolescents. Seasonal Influenza vaccine has been shown to be both safe and effective in pediatric and adolescent patients on chemotherapy treatment although at the Childrens Center for Cancer and Blood Diseases (CCCBD), immunization rates remain suboptimal. We initiated a comprehensive campaign for the 2012-13 flu season with these objectives: 1) evaluate provider attitudes regarding Influenza vaccine, 2) provide a data capture form in the patient medical record to improve vaccine compliance and 3) retrieve electronic medical record (EMR) data on immunization incidence. Methods: The study period was October 1, 2012 through January 31, 2013; a hybrid hard copy/EMR was in use. A Survey Monkey questionnaire was given to CCCBD oncology providers to assess individual influenza vaccine practices. Information was provided how to document vaccination in the EMR. A reminder/data capture form was attached to the hard copy medical record and collected following each patient visit. Forms were tracked to ensure completion for each active oncology patient seen during the campaign period. Patient medical record numbers were cross-referenced with EMR data to determine immunization incidence and the success of the campaign. Results: 100% of providers (46/46) responded to the survey. All respondents believed that the flu vaccine was both safe and efficacious; many reported that the priority of oncology care pre-empted ordering vaccine (27%). Total vaccine doses dispensed increased by 28 % over the previous season (502 doses in 2012-13 vs. 361 doses in 2011-12). 61% of eligible patients with Acute Lymphoblastic Leukemia (ALL) were immunized in 2012-13 compared to 40% of ALL patients in 2011-12. EMR documentation of vaccination also improved during the campaign. Conclusions: A comprehensive campaign to promote Influenza immunization during the most recent flu season was overwhelmingly successful. In-progress improvement in the institutional EMR will further advance our ability to document and retrieve influenza vaccine data for this at-risk population of children and adolescents.

Pediatric patients with intravascular devices: polymicrobial bloodstream infections and risk factors

A retrospective study was conducted, including 61 patients with long-term intravascular devices (IVDs) admitted to the Childrens Hospital Los Angeles with diverse underlying diseases, different types of catheters, and culture-proven catheter-related bloodstream infections (BSIs). Within these patients, 125 catheter-related BSIs occurred, and the incidence of monomicrobial and polymicrobial BSIs was evaluated. Risk factors for polymicrobial BSIs were determined. Forty-two BSIs contained more than one pathogen. These polymicrobial BSIs were observed more often in younger patients (<4.1 years versus ≥4.1 years) and less in patients using venous implanted ports. No other associations were found between the occurrences of polymicrobial BSIs and underlying diseases, other types of catheters, host defense status, parenteral nutrition, recurrences, or catheter removal. Patients with long-term IVDs at a younger age have a higher risk of developing a polymicrobial BSI. Future prospective studies should address the issue of polymicrobial infection in IVDs in more detail.

Voriconazole pharmacokinetics and pharmacodynamics in children

BACKGROUND

Voriconazole pharmacokinetic and pharmacodynamic data are lacking in children.

METHODS

Records at the Childrens Hospital Los Angeles were reviewed for children with > or =1 serum voriconazole concentration measured from 1 May 2006 through 1 June 2007. Information on demographic characteristics, dosing histories, serum concentrations, toxicity and survival, and outcomes was obtained.

RESULTS

A total of 207 voriconazole measurements were obtained from 46 patients (age, 0.8-20.5 years). A 2-compartment Michaelis-Menten pharmacokinetic model fit the data best but explained only 80% of the observed variability. The crude mortality rate was 28%, and each trough serum voriconazole concentration <1000 ng/mL was associated with a 2.6-fold increased odds of death (95% confidence interval, 1.6-4.8; P=.002). Serum voriconazole concentrations were not associated with hepatotoxicity. Simulations predicted an intravenous dose of 7 mg/kg or an oral dose of 200 mg twice daily would achieve a trough >1000 ng/mL in most patients, but with a wide range of possible concentrations.

CONCLUSIONS

We found a pharmacodynamic association between a voriconazole trough >1000 ng/mL and survival and marked pharmacokinetic variability, particularly after enteral dosing, justifying the measurement of serum concentrations.

The Effects of Campath 1H upon Graft-Versus-Host Disease, Infection, Relapse, and Immune Reconstitution in Recipients of Pediatric Unrelated Transplants

Graft-versus-host disease (GVHD) is a cause of serious morbidity and mortality in >50% of recipients of unrelated hematopoietic stem cell transplantation (HSCT). We performed a trial using Campath 1 H pre- and post-HSCT in an attempt to decrease the incidence of GVHD without increasing the risk of infection or relapse. Patients were retrospectively compared to a population of patients who received antithymocyte globulin (ATG) pre- and post-HSCT. Twenty-seven patients were evaluated for this study. Fourteen patients received Campath 1H and 13 patients received ATG. Demographics of patients who received Campath 1H consisted of 9 males and 5 females, with a median age of 13 years (3-17.8 years). Thirteen patients received unrelated bone marrow and 1 patient received unrelated PBSC. Demographics of patients receiving ATG consisted of 9 males, 4 females with a median age of 7.4 years (21 months-19 years). Twelve patients received unrelated bone marrow and 1 patient received unrelated PBSC. Diagnoses were similar between the 2 groups. Patients who received Campath1H received a total dose of 52 mg/m(2) pre-HSCT and 20 mg/m(2) post-HSCT. Patients who received ATG received a total dose of 60 mg/kg pre-HSCT and 100 mg/kg post-HSCT. GVHD prophylaxis and supportive care measures were similar in both groups, including aggressive antimicrobial therapy. There was a significant difference in the incidence of severe (grade III and grade IV) GVHD between the 2 groups (Campath [0 of 14] versus ATG [6 of 13], P = .006). Among the patients who were transplanted for leukemia, there was no significant difference between the 2 groups in terms of relapse (Campath [2 of 14] versus ATG [4 of 9], P = 0.16). The 100-day survival between the 2 groups was not significantly different. Patients receiving Campath 1H had the presence of CD3(+) T cells (>30 cells/mL) in their peripheral blood later than in those who received ATG (64.5 days [Campath 1H] versus 27days [ATG], P = .001). The median time to the development of a normal PHA response occurred later in the Campath 1H arm (283 days[(Campath 1H] versus 88 days [ATG], P = .0001). The median time to an antigen specific response also occurred later in those receiving Campath 1H (365 days [Campath 1H] versus 150 days [ATG], P = .004). There was no significant difference between the 2 groups in terms of fungal or viral infections. Campath 1H is effective in decreasing the incidence of GVHD without increasing the risk of relapse. Although there is a significant delay in immune reconstitution, there was no increase in infectious complications or relapse in recipients of Campath 1H. Further studies are warranted to assess if a lack of difference in infection rates are still demonstrated in larger cohorts.

Ethanol-lock technique for persistent bacteremia of long-term intravascular devices in pediatric patients

OBJECTIVES

To use the ethanol-lock technique (in conjunction with systemic antibiotics) to salvage central lines from removal and to prevent persistence of catheter-related infections among pediatric patients with long-term intravascular devices.

DESIGN

Medical records of patients treated with ethanol locks were retrospectively reviewed from June 1, 2004, through June 22, 2005.

SETTING

Childrens Hospital Los Angeles, Los Angeles, Calif, a tertiary care pediatric hospital. Patients Forty children with diverse underlying disorders were treated for 51 catheter-related infections using the Childrens Hospital Los Angeles ethanol-lock technique.

INTERVENTIONS

Eligible infected central lines were instilled with a dose volume of 0.8 to 1.4 mL of 70% ethanol into the catheter lumen during 12 to 24 hours and then withdrawn. The volume of ethanol used was based on the type of intravascular device.

MAIN OUTCOME MEASURES

Clearance of infection and incidence of recurrence.

RESULTS

Of the 51 ethanol-lock treatments in 40 children, no catheters were removed because of persistent infection. Eighty-eight percent (45/51) of the treated episodes cleared without recurrence (defined as a relapse within 30 days with the same pathogen). Twelve (75%) of 16 polymicrobial isolates and 33 (94%) of 35 monomicrobial isolates were successfully treated. There were no adverse reactions or adverse effects reported.

CONCLUSION

This retrospective study supports the use of the ethanol-lock technique in conjunction with systemic antibiotics as an effective and safe method to retain the use of a previously infected central venous catheter, decrease the need for line removal, and eradicate persistent pathogens in catheter-related infections.