Hematopoietic Cell Transplant Patients Research Articles

Clinical use of measurable residual disease in adult ALL: recommendations from a panel of U.S. experts.

Measurable residual disease (MRD) is a powerful predictor of clinical outcomes in acute lymphoblastic leukemia (ALL). In addition to its clear prognostic importance, MRD information is increasingly used in clinical decision algorithms to guide therapeutic interventions. While it is well-established that achievement of MRD-negative remission is an important endpoint of ALL therapy, the prognostic and therapeutic implications of MRD in an individual patient are influenced by both disease-related factors (e.g. cytomolecular risk) and assay-related factors (e.g. sensitivity, specimen source, and timing of assessment), which add complexity to MRD-guided treatment decisions. In this review, we discuss the data supporting the use of MRD assessment in adult ALL and how this information can rationally inform clinical decisions, including selection of patients for MRD-directed therapies or allogeneic hematopoietic stem cell transplantation. We also discuss important interpretative challenges related to novel high sensitivity next-generation sequencing-based MRD assays, which are becoming increasingly used in clinical practice.

Testing the feasibility of a digital storytelling intervention combined with heart rate variability biofeedback in hematopoietic cell transplant patients

Testing the feasibility of a digital storytelling intervention combined with heart rate variability biofeedback in hematopoietic cell transplant patients

Current status and perspectives of hematopoietic cell transplantation in patients with paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare complement-driven acquired hemolytic anemia with specific presentations of hemoglobinuria, abdominal pain, fatigue, and thrombosis. To review the current therapeutic strategies for PNH, including anti-complement therapy and allogeneic hematopoietic cell transplantation (alloHCT), focusing on the tailoring of the approach to the disease subtype. The outcome of alloHCT varies depending on disease severity, thrombotic history, and response to prior therapies. Non-transplant PNH therapies include anti-C5 monoclonal antibodies that reduce terminal complement activation (eculizumab, ravulizumab, and crovalimab) and proximal complement pathway inhibitors such as pegcetacoplan (C3 inhibitor), iptacopan (complement factor B inhibitor), and danicopan (complement factor D inhibitor). Although complement inhibitors have revolutionized treatment, alloHCT remains the only curative therapy, particularly for patients who are refractory to medical management or have severe cytopenia. This review outlines the conditioning regimens used in alloHCT and summarizes recent studies showing that overall survival rates improve with less toxic conditioning protocols. AlloHCT can be used to manage PNH, particularly in patients who are resistant to or without access to complement-targeted therapies. Any potential cure offered by alloHCT must be counterbalanced by the significant procedure risks, including graft-versus-host disease and transplant-related mortality, particularly in patients with comorbidities. In the case of severe aplastic anemia with an associated PNH clone, immunoablative protocols based on anti-thymocyte globulin serotherapy with fludarabine and cyclophosphamide are recommended. The use of reduced toxicity protocols with fludarabine has been well-documented in patients with classic PNH. A treosulfan/fludarabine-based regimen is recommended; however, there is no consensus on optimal drug selection.

The epidemiology of pediatric oncology and hematopoietic cell transplant admissions to U.S. intensive care units from 2001-2019.

Children with cancer or hematopoietic cell transplant (HCT) frequently require ICU care. We conducted a retrospective cohort study using Healthcare Cost and Utilization Project's State Inpatient Databases from 21 U.S. states from 2001-2019. We included children <18 years with oncologic or HCT diagnosis and used ICD-9-CM and ICD-10-CM codes to identify diagnoses, comorbidities, and organ failures. We used generalized linear Poisson regression and Cuzick's test of trend to evaluate changes from 2001-2019. Among 2,157,991 total pediatric inpatient admissions, 3.9% (n=82,988) were among oncology patients and 0.3% (n=7,381) were among HCT patients. ICU admission prevalence rose from 13.6% in 2001 to 14.4% in 2019 for oncology admissions and declined from 23.9% to 19.5%, for HCT admissions. Between 2001-2019, the prevalence of chronic non-oncologic comorbidities among ICU patients rose from 44.3% to 69.1% for oncology patients (RR 1.60 [95% CI 1.46-1.66]) and from 41.4% to 81.5% (RR 1.94 [95% CI 1.61-2.34]) for HCT patients. The risk of Multiple Organ Dysfunction Syndrome more than tripled for oncology (9.5% to 33.3%; RR 3.52 [95% CI 2.97-4.18]) and HCT (12.4% to 39.7%; RR 3.20 [95% CI 2.09-4.89]) patients. Mortality decreased most for ICU patients with acute myeloid leukemia (AML) (14.6% to 8.5%) and oncology-related HCTs (15.5% to 9.2%). Critically ill pediatric oncology and HCT patients are increasingly medically complex with greater prevalence of chronic comorbidities and organ failure, but mortality did not increase. Pediatric ICUs may require increased financial and staffing support to care for these patients in the future.

Clinical impact of clonal hematopoiesis in hematopoietic cell transplantation: a review, meta-analysis, and call to action.

Hematopoietic cell transplantation (HCT) is the only potentially curative treatment option for many patients with hematologic malignancies. While HCT outcomes have improved drastically over the years, patients and clinicians continue to face numerous survivorship challenges, such as relapse, graft-versus-host disease, and secondary malignancies. Recent literature suggests that clonal hematopoiesis (CH), the presence of a recurrent somatic mutation in hematopoietic cells, in HCT patients or donors may be associated with outcomes in autologous and allogeneic HCT. Herein, we perform a review of the literature and summarize reported associations between CH and clinical outcomes in HCT. For commonly reported outcomes, we used meta-analysis methods to provide estimates of effect sizes when combining results. A total of 32 articles with relevant and independent contributions were included, covering both autologous (N=19) and allogeneic (N=13) HCT. The articles report variable risk for developing outcomes according to CH characteristics, patient disease status, and method of HCT. Using meta-analysis of available results, HCT outcomes with statistically significant effects by CH status include therapy-related myeloid neoplasms (odds ratio =3.65; 95% confidence interval [CI]: 2.18-6.10) and overall survival (hazard ratio [HR]=1.38; 95% CI: 1.20-1.58) in autologous HCT and relapse (HR=0.80; 95% CI: 0.68-0.94) in allogeneic HCT. However, heterogeneity, biases, and limitations in the literature provide challenges for informing the translation of CH to clinical decision- making. We conclude with a call to action and discussion of next steps to build upon the current literature and provide granularity to the true clinical impact of CH in the setting of HCT.

Prognostic Factors Associated With Increased Mortality in Pediatric Veno-Occlusive Disease Following Hematopoietic Cell Transplantation.

Hepatic veno-occlusive disease (VOD) is a life-threatening complication of hematopoietic cell transplantation (HCT) and is categorized as a transplant-related, systemic endothelial disease. Severe VOD can lead to multi-organ dysfunction (MOF) and is associated with a high mortality rate. To evaluate the incidence of VOD in children after HCT and analyze the outcomes and risk factors associated with increased mortality. A retrospective cohort study of 1243 children with malignant and non-malignant diseases who underwent HCT at two large pediatric centers over 20 years. One hundred one patients (8%) developed VOD post HCT. Most patients developed VOD post allogeneic HCT (76%) versus autologous (24%). The incidence of VOD was twice as high in children with malignant diseases compared to non-malignant (68%vs. 32%). A much higher incidence of VOD occurred in patients after a busulfan-based regimen versus total body irradiation-based and treosulfan-based, 73%, 18%, and 1%, respectively. The 100-day survival rate of HCT patients with VOD was 69%. The overall survival rate of the entire group was 50%, showing improvement over the span of the study years, from 40% between 2000 and 2009 to 63% between 2010 and 2021 (p = 0.022). Factors associated with increased mortality included infections before transplant (p = 0.013), conditioning regimen (p = 0.01), abnormal liver function (p = 0.019), presence of ascites (p = 0.008), MOF (p < 0.001), and the need for admission to a pediatric intensive care unit (p < 0.001). There was no significant difference in survival rates between children treated with defibrotide alone or with those treated with defibrotide and steroids (61% and 65%, respectively; p = 0.685). Severe VOD in pediatric patients following HCT remains a life-threatening complication with a high mortality rate. Early diagnosis and treatment with defibrotide are critical for managing this condition. In our cohort, the addition of steroids to defibrotide was not associated with improved outcomes.

Not Just an Oxymoron: The Utilitarian's Guide to Antimicrobial Stewardship in Transplant Infectious Diseases.

Solid organ transplant and hematopoietic cell transplant patients face an increased risk of infectious diseases, greater exposure to antibiotics, and heightened risk of multidrug-resistant organisms (MDROs) due to their immunosuppressed state. Antimicrobial stewardship programs (ASP) are essential in reducing the incidence of MDRO by conserving antimicrobial use, minimizing treatment durations, and improving the appropriate use of diagnostic testing. However, the role of ASP in transplant infectious diseases (TID) is still evolving, necessitating greater collaboration between ASP and transplant programs. This collaboration will mitigate infection risks, reduce infection-associated costs, and improve outcomes. This article reviews the key components for implementing ASP in TID, especially for those that are establishing or growing their ASP to include TID, including specific goals, structure and funding, ASP initiatives (including antibiotic allergy delabeling, diagnostic stewardship, and antiviral/antifungal stewardship), metrics, and educational opportunities.

Outcomes within 100 days of hematopoietic cell transplantation in pediatric patients: insights from an intensive care unit in Colombia.

Hematopoietic cell transplantation (HCT) has become an essential therapeutic modality for pediatric patients with malignant and non-malignant conditions. Despite its effectiveness, many patients experience post-transplant complications often leading into life-threatening conditions requiring specialized care in a Pediatric Intensive Care Unit (PICU). This study aims to describe clinical characteristics associated with mortality in pediatric HCT patients who needed PICU care within 100 days post-transplant in a resource-limited country. A retrospective cohort study was conducted involving pediatric HCT patients (<18 years old) admitted to our PICU from January 2012 to December 2021. Variables were characterized according to their nature, employing appropriate measures of central tendency and dispersion. The relationship between mortality and patient clinical characteristics was assessed using the Chi-square test or the Mann-Whitney U test, as applicable. A p-value of <0.05 was considered statistically significant. A Kaplan Meier survival curve was performed considering the days from HCT to death during PICU admission and a Cox regression analysis was conducted to analyze the association between PRISM III score and risk of death. Data analysis was executed utilizing the STATA SE v18 statistical software package. Of 316 HCTs, 69 patients required admission to the PICU. Haploidentical transplants from related donors were performed in 72.5% of these patients. The primary cause of PICU admission was infection, accounting for 68.1% (n = 47) of cases. Factors significantly associated with mortality included a PRISM III score > 20 (p < 0.002), mechanical ventilation (p < 0.007), renal replacement therapy (p < 0.002) and vasoactive support (p < 0.001). A total of 27 patients succumbed during their PICU stay. Kaplan Meier curve showed a survival rate of 51.6% at100-days post-transplant. A PRISM III score higher than 20 points was related with mortality (Hazard ratio 5.71 CI 95% 2.09-15.5). This study examines critical factors associated with mortality in pediatric HCT recipients who required admission to our PICU within the first 100 days post-transplant. Our findings indicate that infectious complications, alongside the need for advanced cardiovascular, respiratory, and renal support are strongly correlated with mortality. These results underscore the importance of early risk factor identification and targeted interventions to optimize patient outcomes.

Incidence of venous thromboembolic disease and risk of bleeding in critically ill patients with hematologic malignancies: A retrospective study

ObjectiveOur objectives were to describe the use of thromboprophylaxis and the incidence of VTE/bleeding in critically ill patients with hematologic malignancies (HM). DesignRetrospective cohort study (2014–2022). SettingMedic-Surgical Intensive Care Unit (ICU) in a tertiary care academic center. PatientsAdult patients admitted to ICU with a concomitant diagnosis of a hematological malignancy. InterventionsNone. Main variables of interestWe analyzed demographic data, use of thromboprophylaxis and secondary outcomes that included incidence of VTE (venous thromboembolism), bleeding, mortality, severity scores and organ support. We applied a multivariable logistic regression model to examine the risk of thrombosis in the ICU. ResultsWe included 862 ICU admissions (813 unique patients). Thromboprophylaxis was given during 65% of admissions (LMWH 14%, UFH 8%, and SCDs 43%); in 21% it was contraindicated due to thrombocytopenia; 14% of cases lacked documentation on prophylaxis. There were 38 unique incident cases of VTE (27 DVT, 11 PE), constituting 4.4% of ICU episodes. Most of VTE cases happened in patients with various degrees of thrombocytopenia. In the multivariable analysis, SOFA score on the first ICU day was independently associated (OR 0.85, 95% CI 0.76−0.96) with the risk of VTE. Bleeding occurred in 7.2% (minor) and 14.4% (major) of episodes; most frequent sites being CNS, abdomen/GI and pulmonary. ConclusionsIn this cohort of critically ill patients with HM, there was considerable variability in the utilization of DVT prophylaxis, with predominant use of SCDs. The incidence of VTE was 4.4% and major bleeding 14%. Clinical Trial RegistrationNCT05396157. Venous Thromboembolism in Hematologic Malignancy and Hematopoietic Cell Transplant Patients: a Retrospective Study (https://clinicaltrials.gov/).

Use of T2Bacteria Panel in Pediatric Hematopoietic Stem Cell Transplant Patients: A Single Center Experience

Abstract Background Bloodstream infection is a common complication following hematopoietic cell transplant (HCT), occurring in 10-40% of patients (1,2). Rapid identification of causative bacteria is imperative to provide proper empiric therapy and ensure optimal patient outcomes. The T2Bacteria Panel detects five bacterial pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli) using T2 magnetic resonance (T2MR, T2Biosystems, Lexington MA, USA) directly from blood specimens. Previous studies have reported per-patient sensitivity, specificity, and negative predictive value (NPV) of 84-90%, 85.9-90%, and 99.7%, respectively, as well as 100% positive agreement and 98.4% negative agreement when compared to blood culture (3-5). To date, there have been no studies on the use of this test in pediatric HCT recipients. Methods We reviewed all pediatric HCT patients at St. Jude Children’s Research Hospital who had a T2Bacteria Panel performed for fever and suspected infection between January 2019 and September 2022. A total of 706 T2Bacteria Panel results and concurrent blood culture results from 251 unique patients were analyzed to determine assay performance for detection of the 5 targeted pathogens. Results T2Bacteria PCR and blood culture showed concordant results in 97% of cases. Overall, our study revealed 65% positive percent agreement with blood culture and 95% negative percent agreement for bacteremia caused by any of the target pathogens. PPV, NPV, sensitivity and specificity for each organism detected by the panel, and the panel overall, are presented in Table 1. Positive predictive value ranged from 28-73%. Negative predictive value was high for all organisms (98-100%). Sensitivity was highest for Pseudomonas aeruginosa (88%), and lowest for Escherichia coli (44%). Specificity was high for all organisms (97-99%). Conclusion In pediatric HSCT patients, the T2Bacteria Panel was most useful for rapidly ruling out the presence of target pathogens, with high negative percent agreement, NPV, and specificity. Positive percent agreement was lower than noted in previous studies. Positive predictive value and sensitivity varied per pathogen.

CAR T-cell therapy combined with autologous hematopoietic cell transplantation in patients with refractory/relapsed Burkitt Lymphoma

Burkitt lymphoma (BL) is a highly aggressive type of non-Hodgkin lymphomas that have a high likelihood of relapse and are highly refractory to initial treatment. While high-intensity chemotherapy has improved the outcomes, many adult patients still experience treatment failure, and effective salvage therapies are limited. This study retrospectively analyzed the outcomes of 21 relapsed or refractory (R/R) adult BL patients treated with chimeric antigen receptor T-cell (CAR-T) therapy, combined or not with hematopoietic cell transplantation (HCT), across four Chinese hospitals. Patients were grouped based on treatment strategies: autologous HCT followed by CAR T-cell therapy (auto-HCT+CART group, n = 8), and CAR T-cell therapy alone (CART group, n = 13). The auto-HCT+CART group demonstrated superior outcomes, with an overall response rate (ORR) of 87.5 % and significantly higher 1-year overall survival (OS) and progression-free survival (PFS) rates compared to the CART group (p = 0.014 and p = 0.045, respectively). These findings suggest that combining auto-HCT with CAR-T therapy may enhance long-term disease control in R/R BL patients. These encouraging results highlight the need for further prospective studies to validate our data.

Frailty and pre-frailty associated with long-term diminished physical performance and quality of life in breast cancer and hematopoietic cell transplant survivors.

Physical frailty as a sign of accelerated aging is not well characterized in breast cancer (BC) and hematopoietic cell transplant (HCT) survivors and its correlation with outcomes and quality of life (QOL) is not defined. We conducted a prospective study to determine the prevalence of frailty in adult BC and HCT survivors, examine its impact on QOL, and determine its association with p16INK4a, a molecular biomarker for biological aging. The study included 59 BC and 65 HCT survivors. Median age was 60 years (range 27-81), 68.5% were female and 49.2% were 18-59 vs. 51.8% ≥60 years old. A total of 71 (57.3%) were "fit" (frailty score 0) vs. 53 (42.7%) were pre-frailty/frail (frailty scores ≥1), and of the latter 17 (32.1%) were BC and 36 (67.9%) HCT patients. On multivariate analysis, patients >60 years were twice as likely to be frail (OR 2.04, 95% CI, 0.96-4.33; p=0.07), HCT were more likely to be frail compared to BC patients, and female HCT had 2.43 (95% CI, 0.92-6.40) and male HCT patients had 3.25 (95% CI, 1.37-7.72) times higher risk of frail; p=0.02. Frailty was associated with significant decline in QOL, measured by Medical Outcomes Study (MOS) Short Form 36 (SF-36) Physical Component Summary (PCS) and Mental Component Summary (MCS), and FACT (Functional Assessment of Cancer Therapy) scores. p16INK4a expression was higher in those who were frail, older than 60, and with higher expression in frail vs. fit patients who are 18-59 years. Our study highlights the high prevalence of frailty in survivors with detrimental effects on physical and overall wellbeing, and supports an association between frailty and the senescence marker p16INK4a.

Successful Allogeneic Hematopoietic Cell Transplantation for Patients with IL10RA Deficiency in Japan.

IL10RA (IL10 receptor subunit alpha) deficiency is an autosomal recessive disease that causes inflammatory bowel disease during early infancy. Its clinical course is often fatal and the only curative treatment is allogeneic hematopoietic cell transplantation (HCT). In Japan, only case reports are available, and there are no comprehensive reports of treatment outcomes. We retrospectively analyzed patients with IL10RA deficiency in Japan. Two newly identified and five previously reported patients were included in this study. Five patients underwent HCT; one untransplanted patient survived to age 14, and one died of influenza encephalopathy before transplantation. All five HCT recipients underwent HCT at the age before 2 years. They all were conditioned with fludarabine/busulfan- or fludarabine /melphalan-based regimens. The donor source was human leukocyte antigen haploidentical donor bone marrow (BM) for two patients and unrelated umbilical cord blood (CB) for two patients. One patient experienced graft failure with unrelated CB and required a second transplant with unrelated BM. All patients who underwent HCT survived and demonstrated an improved performance status. In cases of IL10RA deficiency, the need for transplantation should be promptly assessed, and early transplantation should be considered. (190/250).

Abstract 8: Facilitating Hematopoietic Cell Transplant for Patients with Infantile Krabbe Disease Identified by Newborn Screening

Abstract 8: Facilitating Hematopoietic Cell Transplant for Patients with Infantile Krabbe Disease Identified by Newborn Screening

Predictors of fluid overload in allogeneic hematopoietic cell transplant patients receiving post-transplant cyclophosphamide.

Fluid overload (FO) commonly occurs during hospitalization for allogeneic hematopoietic cell transplantation (HCT). Grade 2-4 FO is associated with day +100 non-relapse mortality.1 Post-transplant cyclophosphamide (PTCY) for graft-versus-host disease prevention requires aggressive IV hydration to prevent hemorrhagic cystitis. This is a single-center, retrospective, observational study conducted at an academic medical center via electronic chart review. Included patients received allogeneic HCT followed by PTCY on days +3 and +4. Patients were excluded for age < 18 years or incarceration. Primary endpoints are incidence of Grade 2-4 FO and associated risk factors. Descriptive and inferential statistics (i.e., Fisher's exact test, multivariable regression analysis) were used. Of 97 patients screened, 95 were included and 2 were excluded due to absence of weight measurements needed to grade FO. Median age was 60 years, 66.3% were male, 91.6% received reduced-intensity conditioning, 72.6% received haploidentical HCT, 44.2% were ECOG 0, and 11.6% had diastolic dysfunction. Incidence of grade 2-4 FO was 33.7% (n = 32). Univariate analyses found age (continuous; p = 0.04) and BSA < 1.7 m2 (p = 0.006) as independent factors associated with grade 2-4 FO. Multivariable regression analysis found 3.3% higher risk with every 1-year increase in age ranging from f 20 to 78 years (OR 1.033, 95% CI 1.001, 1.006; p = 0.0453) and 82.8% lower risk with BSA ≥ 1.7 m2 (OR 0.172, 95% CI 0.051, 0.588; p = 0.005) after adjusting for co-variates. Increasing age and BSA < 1.7 m2 are risk factors associated with grade 2-4 FO during hospitalization for allogeneic HCT with PTCY.

Early Toxicity and Efficacy of Four Different Conditioning Regimens for Autologous Hematopoietic Cell Transplantation in Patients With Lymphoma: Impact of Drug Shortages in a Resource-Constrained Country

High-dose therapy followed by autologous hematopoietic cell transplant (AHCT) remains a viable consolidation strategy for a subset of patients with relapsed or refractory (R/R) lymphomas. BEAM (carmustine, etoposide, cytarabine, and melphalan) is widely recognized as the predominant conditioning regimen due to its satisfactory efficacy and tolerability. Nevertheless, shortages of carmustine and melphalan have compelled clinicians to explore alternative conditioning regimens. The aim of this study was to compare the toxicity and transplant outcomes following BEAM, CBV (carmustine, etoposide, cyclophosphamide), BuMel (busulfan, melphalan), and BendaEAM (bendamustine, etoposide, cytarabine, melphalan). We retrospectively analyzed data from 213 patients (CBV 65, BuMel 42, BEAM 68, BendaEAM 38) with R/R lymphomas undergoing AHCT between 2014 and 2020. Multivariate models were employed to evaluate toxicity and transplant outcomes based on conditioning type. Among grade III to IV toxicities, oral mucositis was more frequently observed with BuMel (45%) and BendaEAM (24%) compared to BEAM (15%) and CVB (6%, P ≤ .001). Diarrhea was more common with BendaEAM (42%) and less frequent with BuMel (7%, P = .01). Acute kidney injury was only found after BendaEAM (11%). Febrile neutropenia and infectious complications were more frequent following BendaEAM. Frequencies of other treatment-related toxicities did not significantly differ according to conditioning type. BendaEAM (odds ratio [OR] 3.07, P = .014) and BuMel (OR 4.27, P = .002) were independently associated with higher grade III to IV toxicity up to D+100. However, there were no significant differences in relapse/progression, nonrelapse mortality, progression-free survival, or overall survival among the four regimens. BuMel and BendaEAM were associated with a higher rate of grade III to IV toxicity. Carmustine-based regimens appeared to be less toxic and safer; however, there were no significant differences in transplant outcomes. The utilization of alternative preparative regimens due to drug shortages may potentially lead to increased toxicity after AHCT for lymphoma.

Challenges with sirolimus experimental data to inform QSP model of post-transplantation cyclophosphamide regimens.

Dose optimization of sirolimus may further improve outcomes in allogeneic hematopoietic cell transplant (HCT) patients receiving post-transplantation cyclophosphamide (PTCy) to prevent graft-versus-host disease (GVHD). Sirolimus exposure-response association studies in HCT patients (i.e., the association of trough concentration with clinical outcomes) have been conflicting. Sirolimus has important effects on T-cells, including conventional (Tcons) and regulatory T-cells (Tregs), both of which have been implicated in the mechanisms by which PTCy prevents GVHD, but there is an absence of validated biomarkers of sirolimus effects on these cell subsets. Considering the paucity of existing biomarkers and the complexities of the immune system, we conducted a literature review to inform a quantitative systems pharmacology (QSP) model of GVHD. The published literature presented multiple challenges. The sirolimus pharmacokinetic models insufficiently describe sirolimus distribution to relevant physiological compartments. Despite multiple publications describing sirolimus effects on Tcons and Tregs in preclinical and human exvivo models, consistent parameters relating sirolimus concentrations to circulating Tcons and Tregs could not be found. Each aspect presents a challenge in building a QSP model of sirolimus and its temporal effects on T-cell subsets and GVHD prevention. To optimize GVHD prevention regimens, phase I studies and systematic studies of immunosuppressant concentration-effect association are needed for QSP modeling.

Impact of dexamethasone on transplant-related mortality in pediatric patients: a multi-site, propensity score-weighted, retrospective assessment.

Dexamethasone use during hematopoietic cell transplant (HCT) conditioning varies between pediatric centers. This study aimed to estimate the difference in 1-year treatment-related mortality (TRM) between patients who did or did not receive dexamethasone during HCT conditioning. Secondary objectives were to estimate the difference between dexamethasone-exposed and dexamethasone-unexposed groups in 1-year event-free survival (EFS), time to neutrophil engraftment, acute graft-versus-host disease (aGVHD), and invasive fungal disease (IFD) at day + 100. This was a seven-site, international, retrospective cohort study. Patients < 18years old undergoing their first allogeneic or autologous myeloablative HCT for hematologic malignancy or aplastic anemia between January 1, 2012, and July 31, 2017, were included. To control for potential confounders, propensity score weighting was used to calculate the standardized mean difference for all endpoints. Among 242 patients, 140 received dexamethasone during HCT conditioning and 102 did not. TRM was unaffected by dexamethasone exposure (1.7%; 95% CI - 7.4, 10.2%). Between-group differences in secondary outcomes were small. However, dexamethasone exposure significantly increased possible, probable, and proven IFD incidence (9.0%, 95% CI 0.8, 17.3%). TRM is not increased in pediatric patients who receive dexamethasone during HCT conditioning. Clinicians should consider potential IFD risk when selecting chemotherapy-induced vomiting prophylaxis for pediatric HCT patients.

Pediatric Hematology and Oncology Patients on Extracorporeal Membrane Oxygenation: Outcomes in a Multicenter, Retrospective Cohort, 2009-2021.

To describe characteristics associated with survival for pediatric patients with an oncologic diagnosis or hematopoietic cell transplant (HCT) supported with extracorporeal membrane oxygenation (ECMO). Multicenter, retrospective study. Sixteen PICUs in the United States and Israel. We included patients aged younger than 19 years with an oncologic diagnosis or HCT who required ECMO support between 2009 and 2021. None. A total of 149 patients were included in the study cohort. There were 118 patients with an oncologic diagnosis and 31 that received HCT. The indications for ECMO were respiratory failure (46%), combined respiratory and cardiac failure (28%), and cardiac failure (25%). Venovenous (V-V) ECMO was used in 45% of patients, with 53% of patients being placed on venoarterial (V-A) ECMO. For oncologic and HCT groups, survival to ECMO decannulation was 52% (62/118) and 64% (20/31), and survival to hospital discharge was 36% (43/118) and 42% (13/31), respectively. After adjusting for other factors, requiring cardiopulmonary resuscitation was associated with greater odds ratio of mortality (3.0 [95% CI, 1.2-7.7]). Survival to ECMO decannulation of pediatric oncologic and HCT patients in this study was 52-64%, depending upon diagnosis. However, survival to hospital discharge remains poor. Future research should prioritize understanding factors contributing to this survival gap within these patient populations.

Clinical Pharmacokinetics and Pharmacodynamics of Letermovir in Allogenic Hematopoietic Cell Transplantation.

Letermovir is a newly developed antiviral agent used for the prophylaxis of human cytomegalovirus infections in patients undergoing allogeneic hematopoietic cell transplantation. This novel anti-cytomegalovirus drug, used for the prophylaxis of cytomegalovirus reactivation until approximately 200 days after transplantation, effectively reduces the risk of clinically significant cytomegalovirus infection. No human counterpart exists for the terminase complex; letermovir is virus specific and lacks some toxicities previously observed with other anti-cytomegalovirus drugs, such as cytopenia and nephrotoxicity. The absolute bioavailability of letermovir in healthy individuals is estimated to be 94% based on a population-pharmacokinetic analysis. In contrast, oral administration of letermovir to patients undergoing hematopoietic cell transplantation results in lower exposure than that in healthy individuals. Renal or hepatic impairment does not influence the intrinsic clearance of letermovir. Co-administration of letermovir may alter the plasma concentrations of other drugs, including itself, as it acts as a substrate and inhibitor/inducer of several drug-metabolizing enzymes and transporters. In particular, attention should be paid to the drug-drug interactions between letermovir and calcineurin inhibitors or azole antifungal agents, which are commonly used in patients undergoing hematopoietic cell transplantation. This article reviews and summarizes the clinical pharmacokinetics and pharmacodynamics of letermovir, focusing on patients undergoing hematopoietic cell transplantation, healthy individuals, and specific patient subsets.