A Need for a Novel Survival Risk Scoring System for Intensive Care Admissions Due to Sepsis in Pediatric Hematology/Oncology Patients.

Background: Children with hemato-oncological diseases or following stem cell transplantation (SCT) are at high risk for life-threatening infections; sepsis in this population constitutes a substantial proportion of pediatric intensive care unit (PICU) admissions. The current pediatric prognostic scoring tools to evaluate illness severity and mortality risk are designed for the general pediatric population and may not be adequate for this vulnerable subpopulation. Methods: Retrospective analysis was performed on all PICU admissions for sepsis in children with hemato-oncological diseases or post-SCT, in a single tertiary pediatric hospital between 2008 and 2021 (n = 233). We collected and analyzed demographic, clinical, and laboratory data and outcomes for all patients, and evaluated the accuracy of two major prognostic scoring tools, the Pediatric Logistic Organ Dysfunction-2 (PELOD-2) and the Pediatric Risk of Mortality III (PRISM III). Furthermore, we created a new risk-assessment model that contains additional parameters uniquely relevant to this population. Results: The survival rate for the cohort was 83%. The predictive accuracies of PELOD-2 and PRISM III, as determined by the area under the curve (AUC), were 83% and 78%, respectively. Nine new parameters were identified as clinically significant: age, SCT, viral infection, fungal infection, central venous line removal, vasoactive inotropic score, bilirubin level, C-reactive protein level, and prolonged neutropenia. Unique scoring systems were established by the integration of these new parameters into the algorithm; the new systems significantly improved their predictive accuracy to 91% (p = 0.01) and 89% (p < 0.001), respectively. Conclusions: The predictive accuracies (AUC) of the PELOD-2 and PRISM III scores are limited in children with hemato-oncological diseases admitted to PICU with sepsis. These results highlight the need to develop a risk-assessment tool adjusted to this special population. Such new scoring should represent their unique characteristics including their degree of immunosuppression and be validated in a large multi-center prospective study.

Pediatric myelodysplastic syndrome with inflammatory manifestations: Diagnosis, genetics, treatment, and outcome.

BACKGROUND: Inflammatory manifestations (IM) are well described in adult patients with myelodysplastic syndrome (MDS), but the presentation is highly variable and no standardized treatment exists. This phenomenon is rarely reported in children. As more pediatric patients are hematopoietic stem cell transplantation (HSCT) candidates, the role of anti-inflammatory treatment in relation to HSCT should be defined. PROCEDURE: Here, we report a series of five children from a tertiary center. We describe the clinical presentation, molecular findings, and treatment options. RESULTS: All patients presented with advanced MDS with blast percentages ranging 10-30%, all had severe IM. One patient had MDS secondary to severe congenital neutropenia, the other four patients had presumably primary MDS. All four were found to harbor a PTPN11 gene driver mutation, which is found in 35% of cases of juvenile myelomonocytic leukemia (JMML). The mutation was present in the myeloid lineage but not in T lymphocytes. Three had symptoms of Behcet's-like disease with trisomy 8 in their bone marrow. All patients were treated with anti-inflammatory medications (mainly systemic steroids) in an attempt to bring them to allogeneic HSCT in a better clinical condition. All demonstrated clinical improvement as well as regression in their MDS status post anti-inflammatory treatment. All have recovered from both MDS and their inflammatory symptoms post HSCT. CONCLUSION: Primary pediatric MDS with IM is driven in some cases by PTPN11 mutations, and might be on the clinical spectrum of JMML. Anti-inflammatory treatment may reverse MDS progression and improve the outcome of subsequent HSCT.

Second Hematopoietic Stem Cell Transplantation for Post-Transplantation Relapsed Acute Leukemia in Children: A Retrospective EBMT-PDWP Study.

Outcome data were collected from the European Society for Blood and Marrow Transplantation registry on 373 children from 120 centers with relapsed leukemia (214 with acute lymphoblastic leukemia [ALL] and 159 with acute myelogenous leukemia [AML]) who underwent second allogeneic hematopoietic stem cell transplantation (HSCT) between 2004 and 2013. Overall survival (OS) was 38% at 2 years and 29% at 5 years, and leukemia-free survival (LFS) was 30% at 2 years and 25% at 5 years. Median follow-up after second HSCT was 36.4 months in the ALL group and 50.2 months in the AML group. In the ALL group, OS was 43% at 2 years and 33% at 5 years, and LFS was 34% at 2 years and 31% at 5 years. In the AML group, OS was 32% at 2 years and 24% at 5 years, and LFS was 24% at 2 years and 17% at 5 years. The 2-year nonrelapse mortality (NRM) rate was 22% in the ALL group and 18% in the AML group. Favorable prognostic factors (P < .05) for OS and LFS included >12 months between transplantations and chronic graft-versus-host disease after the first HSCT (in both groups), complete response before the second HSCT (ALL group only), and age >12 years (AML group only). Findings were more consistent over time in the ALL group, with no significant differences between 2-year and 5-year rates of relapse, NRM, and LFS. Children with relapsed acute leukemias have a substantial likelihood of long-term survival following second HSCT. Given the many novel targeted and immunomodulation therapies currently under development, it is important to identify specific patient subpopulations that may benefit from a second HSCT compared with those better suited to new approaches.

Calcineurin inhibitor-free strategies for prophylaxis and treatment of GVHD in children with posterior reversible encephalopathy syndrome after stem cell transplantation.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is a distinct clinico-radiologic entity that can occur following allogeneic hematopoietic stem cell transplantation, often in the context of treatment with calcineurin inhibitors (CNIs). PROCEDURE: We describe the results of CNI-free management of 14 children with PRES and review the clinical and radiologic manifestations of their presentation. RESULTS: Discontinuation of CNIs usually resulted in remission of PRES, but patients with established graft versus host disease (GVHD) at the time when treatment was changed often experienced progressive GVHD despite administration of immune suppressive and modulating treatments. All but three patients experienced full neurologic recovery. Nine children died as a result of either GVHD, disease relapse, or severe infection. CONCLUSIONS: Discontinuation of CNIs results in neurologic improvement in most cases, but superior alternative immune modulatory treatment is needed to prevent progression of established GVHD.

Bone marrow transplantation for non-malignant diseases using treosulfan-based conditioning.

BACKGROUND: Treosulfan (treo) is an alkylating agent with a low acute toxicity profile that is increasingly used in hematopoietic stem cell transplantation, predominantly in non-malignant diseases. Treosulfan is usually combined with additional agents, but there is scant evidence to allow comparison between different conditioning protocols using treosulfan. We present the experience of three pediatric transplantation centers in Israel using different treosulfan-based conditioning regimens. PROCEDURE: Data were collected retrospectively on 44 children who underwent 45 hematopoietic stem cell transplantations using treosulfan in combination with either fludarabine (flu) and thiotepa (tt) (n = 20), cyclophosphamide (cy) (n = 6) or fludarabine alone (n = 19). RESULTS: Overall survival (OS) was 70.5%. Disease free survival (DFS) was 54.6%. There was no statistically significant difference between treatment groups in either OS or DFS. Overall survival in patients younger than one year was higher (88.2%). There were significantly more patients with 100% donor chimerism transplanted with flu/treo/tt compared with flu/treo or treo/cy (94.7% compared to 66.7% and 16.7%, respectively). Further prospective studies are required to determine the optimal treosulfan-based preparative regimen for children with non-malignant diseases. Pediatr Blood Cancer 2015;62:299-304. © 2014 Wiley Periodicals, Inc.

Peripheral blood stem-cell harvest using percutaneous arterial lines in children.

BACKGROUND: Autologous peripheral blood stem-cell collection (PBSCC) in children has become an integral part of contemporary treatment protocols, but the procedure is often complicated due to technical issues related to vascular access. Central line placement is often implemented to surmount this problem, but is associated with complications such as bleeding, thrombosis and pneumothorax. As an alternative we have introduced the use of radial arterial lines for PBSCC in children. PROCEDURE: Data from autologous stem cell collections performed from October 2002 to December 2011 using a radial arterial line were collected. RESULTS: A total of 372 PBSCC procedures were performed during the study period; an arterial line was used in 311 PBSCC's in 208 children. The average patient age and weight were 7.9 years (SD 5.4) and 28.3 kg (SD 20.4), respectively. The smallest patient was 9 months old and weighed 7 kg. The mean total volume processed was 8,593 cm(3) (SD 4,854), and the mean number of blood volumes processed was 4.3. Mean collection time for a single blood volume was 55 minutes (SD 15.5). The mean number of CD34+ cells collected per donation was 5.8 × 10(6) /kg. Ninety-seven patients (46%) required more than one collection to meet the requested CD34+ cell target. No serious adverse effects associated with vascular access occurred in this cohort. CONCLUSION: Percutaneous placement of radial artery catheters can be rapidly and safely performed in very small infants and in children with difficult venous access. This technique provides a reliable platform for efficient PBSCC.

Impact of conditioning on outcome of hematopoietic stem cell transplantation for wiskott-Aldrich syndrome.

Hematopoietic stem cell transplantation (HSCT) is the treatment of choice for Wiskott-Aldrich syndrome (WAS). The aim of this retrospective study is to report the effect of the conditioning regimen and donor source on disease-free survival (DFS) in children undergoing HSCT for WAS. Fourteen children who underwent HSCT at 4 Israeli centers from 1996 to 2011 were included in this study. Five children were transplanted from matched related donors (4/5 siblings, 1/5 fully matched uncle) and other donors were used in 9 children. Six patients were conditioned with full dose busulfan/cyclophosphamide (Bu/Cy) whereas 8 patients were conditioned with other regimens. Thirteen of 14 patients (92.8%) are alive with a median follow-up of 3.4 years (range, 5 mo to 12.5 y). Nine patients (64.3%) survive with complete clinical, immunologic, and hematologic recovery. Children conditioned with full dose Bu/Cy had a 100% DFS, compared with children conditioned with other regimens, 25%±19% (P=0.022). Donor source was not associated with DFS. Graft failure was related to the use of conditioning regimens other than full dose Bu/Cy and not to the donor source. Further studies are required to determine the best conditioning regimen and optimal donor source for children with WAS.

Pharmacologic modulation of niche accessibility via tyrosine kinase inhibition enhances marrow and thymic engraftment after hematopoietic stem cell transplantation.

Essential survival signals within hematopoietic stem cell (HSC) and thymic niches are mediated by receptor tyrosine kinases, which can be reversibly inhibited using clinically available drugs. We studied whether sunitinib, a multityrosine kinase inhibitor that inhibits KIT, enhances engraftment after bone marrow transplantation (BMT) in mice. Sunitinib diminished hematopoietic progenitor cell numbers, and sunitinib enhanced marrow, peripheral myeloid, and lymphoid engraftment after BMT in Rag1(-/-) mice. Sunitinib augmented HSC engraftment because recipients displayed increased myeloid and lymphoid engraftment and because sunitinib-treated recipients of purified HSCs showed enhanced engraftment of secondary hosts. However, sunitinib preferentially augmented T-cell engraftment with lesser effects on myeloid and HSC engraftment. Consistent with this, sunitinib preferentially depleted the early thymic progenitor subset in the thymus. Sunitinib did not increase engraftment in mice with deficient KIT signaling, and the pattern of more potent effects on T cell compared with HSC engraftment observed in sunitinib-treated hosts was also observed after BMT into KIT(W/Wv) mice. These results implicate KIT as a critical modulator of thymic niches. We conclude that transient, pharmacologic inhibition of KIT enhances accessibility of marrow and thymic niches, and provides a novel, noncytotoxic approach to accomplish engraftment after stem cell transplantation.

Bispecific Antibodies and Other Non-CAR Targeted Therapies and HSCT: Decreased Toxicity for Better Transplant Outcome in Paediatric ALL?

This review will address the place of innovative, non-chemotherapy, non-CAR-T targeted therapies in the treatment of Acute Lymphoblastic Leukaemia (ALL), focusing on their use in the hematopoietic stem cell transplant (HSCT) context. The focus will be on the agent with the most experience to date, namely the bispecific T-cell engater (BiTE) blinatumomab, but references to antibody-drug conjugates (ADCs) such as inotuzumab ozogamicin and monoclonal antibodies such as daratumamab will be made as well. Specific issues to be addressed include: (1) The use of these agents to reduce measurable residual disease (MRD) prior to HSCT and their potential for improved transplant outcomes due to reduced toxicity compared to traditional chemotherapy salvage, as well as potentially increased toxicity with HSCT with particular agents; (2) the appropriate sequencing of innovative therapies, i.e., when to use BiTEs or antibodies versus CARs pre- and/or post-HSCT; this will include also the potential for impact on response of one group of agents on response to the other; (3) the role of these agents particularly in the post-HSCT relapse setting, or as maintenance to prevent relapse in this setting; (4) special populations in which these agents may substitute for traditional chemotherapy during induction or consolidation in patients with predisposing factors for toxicity with traditional therapy (e.g., Trisomy 21, infants), or those who develop infectious complications precluding delivery of full standard-of-care (SOC) chemotherapy during induction/consolidation (e.g., fungal infections); (5) the evidence we have to date regarding the potential for substitution of blinatumomab for some of the standard chemotherapy agents used pre-HSCT in patients without the above risk factors for toxicity, but with high risk disease going into transplant, in an attempt to decrease current rates of transplant-related mortality as well as morbidity; (6) the unique toxicity profile of these agents and concerns regarding particular side effects in the HSCT context. The manuscript will include both the data we have to date regarding the above issues, ongoing studies that are trying to explore them, and suggestions for future studies to further refine our knowledge base.

FDA Approval Summary: (Daunorubicin and Cytarabine) Liposome for Injection for the Treatment of Adults with High-Risk Acute Myeloid Leukemia.

On August 3, 2017, the FDA granted regular approval to Vyxeos (also known as CPX-351; Jazz Pharmaceuticals), a liposomal formulation of daunorubicin and cytarabine in a fixed combination, for the treatment of adults with newly diagnosed therapy-related acute myeloid leukemia (t-AML) or acute myeloid leukemia (AML) with myelodysplasia-related changes (AML-MRC). Approval was based on data from Study CLTR0310-301, a randomized, multicenter, open-label, active-controlled trial comparing Vyxeos with a standard combination of daunorubicin and cytarabine ("7+3") in 309 patients 60-75 years of age with newly diagnosed t-AML or AML-MRC. Because of elemental copper concerns with the Vyxeos formulation, patients with Wilson disease were excluded from the study. Vyxeos demonstrated an improvement in overall survival (HR 0.69; 95% confidence interval, 0.52-0.90; P = 0.005) with an estimated median overall survival of 9.6 months compared with 5.9 months for the "7+3" control arm. The toxicity profile of Vyxeos was similar to that seen with standard "7+3" with the exception of more prolonged neutropenia and thrombocytopenia on the Vyxeos arm. Because the pharmacology of Vyxeos differs from that of other formulations of daunorubicin and cytarabine, labeling includes a warning against interchanging formulations during treatment. This is the first FDA-approved treatment specifically for patients with t-AML or AML-MRC.

Beyond maximum grade: modernising the assessment and reporting of adverse events in haematological malignancies.

Tremendous progress in treatment and outcomes has been achieved across the whole range of haematological malignancies in the past two decades. Although cure rates for aggressive malignancies have increased, nowhere has progress been more impactful than in the management of typically incurable forms of haematological cancer. Population-based data have shown that 5-year survival for patients with chronic myelogenous and chronic lymphocytic leukaemia, indolent B-cell lymphomas, and multiple myeloma has improved markedly. This improvement is a result of substantial changes in disease management strategies in these malignancies. Several haematological malignancies are now chronic diseases that are treated with continuously administered therapies that have unique side-effects over time. In this Commission, an international panel of clinicians, clinical investigators, methodologists, regulators, and patient advocates representing a broad range of academic and clinical cancer expertise examine adverse events in haematological malignancies. The issues pertaining to assessment of adverse events examined here are relevant to a range of malignancies and have been, to date, underexplored in the context of haematology. The aim of this Commission is to improve toxicity assessment in clinical trials in haematological malignancies by critically examining the current process of adverse event assessment, highlighting the need to incorporate patient-reported outcomes, addressing issues unique to stem-cell transplantation and survivorship, appraising challenges in regulatory approval, and evaluating toxicity in real-world patients. We have identified a range of priority issues in these areas and defined potential solutions to challenges associated with adverse event assessment in the current treatment landscape of haematological malignancies.

Effectiveness of long-term routine pulmonary function surveillance following pediatric hematopoietic stem cell transplantation.

INTRODUCTION: Pulmonary complications following hematopoietic stem cell transplantation (HSCT) are common and often subclinical. Thus, periodic pulmonary function testing (PFT) is mandatory. This study sought to evaluate the effectiveness of long-term PFT surveillance for children undergoing HSCT and identify potential risk factors. METHODS: We reviewed long-term PFT for HSCT patients at a tertiary pediatric center. Inclusion criteria were PFT prior to and at least once following HSCT. RESULTS: Fifty-seven patients performed 202 spirometry and 193 plethysmographic maneuvers; 41 were tested during the first year after HSCT, but only 29 were evaluated consistently long term (2-12 years). FVC and FEV(1) decreased gradually suggesting a restrictive ventilatory defect: FVC % predicted [mean ± SD] dropped from 91 ± 14% to 85 ± 17% after 0-24 months and 80 ± 19% beyond 2 years (P = 0.01) whereas FEV(1) dropped from 95 ± 16% to 88 ± 19% and 82 ± 20%, respectively (P = 0.002). A slight reduction in TLC was observed. Those undergoing allogeneic HSCT had a greater decline in FVC (P = 0.025) and FEV(1) (P = 0.025) as did those conditioned with radiation, regarding both FVC (P = 0.003) and FEV(1) (P = 0.002). Decline occurred earlier (≤2 years) after chemotherapy compared with radiation. Seven children had severe irreversible obstruction at >2 years despite therapeutic intervention. CONCLUSIONS: Most survivors of childhood HSCT maintain almost normal pulmonary function although mild restrictive lung disease may develop, particularly following allogeneic HSCT and conditioning with radiation. Severe airways obstruction developed in a small minority. The surveillance protocol for PFT needs to be followed more stringently to enable intervention possibly before early subclinical changes progress and become irreversible.

Val-boroPro accelerates T cell priming via modulation of dendritic cell trafficking resulting in complete regression of established murine tumors.

Although tumors naturally prime adaptive immune responses, tolerance may limit the capacity to control progression and can compromise effectiveness of immune-based therapies for cancer. Post-proline cleaving enzymes (PPCE) modulate protein function through N-terminal dipeptide cleavage and inhibition of these enzymes has been shown to have anti-tumor activity. We investigated the mechanism by which Val-boroPro, a boronic dipeptide that inhibits post-proline cleaving enzymes, mediates tumor regression and tested whether this agent could serve as a novel immune adjuvant to dendritic cell vaccines in two different murine syngeneic murine tumors. In mice challenged with MB49, which expresses the HY antigen complex, T cell responses primed by the tumor with and without Val-boroPro were measured using interferon gamma ELISPOT. Antibody depletion and gene-deficient mice were used to establish the immune cell subsets required for tumor regression. We demonstrate that Val-boroPro mediates tumor eradication by accelerating the expansion of tumor-specific T cells. Interestingly, T cells primed by tumor during Val-boroPro treatment demonstrate increased capacity to reject tumors following adoptive transfer without further treatment of the recipient. Val-boroPro -mediated tumor regression requires dendritic cells and is associated with enhanced trafficking of dendritic cells to tumor draining lymph nodes. Finally, dendritic cell vaccination combined with Val-boroPro treatment results in complete regression of established tumors. Our findings demonstrate that Val-boroPro has antitumor activity and a novel mechanism of action that involves more robust DC trafficking with earlier priming of T cells. Finally, we show that Val-boroPro has potent adjuvant properties resulting in an effective therapeutic vaccine.