Characteristics and treatment of acute myeloid neoplasms with cutaneous involvement in infants up to 6 months of age: A retrospective study

BACKGROUND

Myeloid neoplasms account for 50% of cases of pediatric leukemias in infants. Approximately 25%-50% of patients with newborn leukemia have cutaneous extramedullary disease (EMD). In less than 10% of patients, aleukemic leukemia cutis or isolated extramedullary disease with cutaneous involvement (cEMD) occurs when skin lesions appear prior to bone marrow involvement and systemic symptoms. Interestingly, in acute myeloid leukemia with cutaneous EMD (AML-cEMD) and cEMD, spontaneous remissions have been reported.

METHOD

This is a multicentric retrospective cohort study aiming to describe characteristics, treatment, and outcome of infants with either cEMD or presence of cutaneous disease with involvement of the bone marrow (AML-cEMD). This study included patients born between 1990 and 2018 from Italy, the Netherlands, Switzerland, and the United States, diagnosed between 0 and 6 months of life with cEMD or AML-cEMD. Descriptive statistics, Fisher's exact test, Kaplan-Meier method, and log rank test were applied.

RESULTS

The cohort consisted of n = 50 patients, including 42 AML-cEMD and eight cEMD patients. The most common genetic mutation found was a KMT2A rearrangement (n = 26, 52%). Overall 5-year event-free survival (EFS) and overall survival (OS) were 66% [confidence interval (CI): 51-78] and 75% [CI: 60-85], respectively. In two patients, complete spontaneous remission occurred without any therapy. Central nervous system (CNS) involvement was found in 25% of cEMD patients. No difference in outcomes was observed between the AML-cEMD and cEMD groups, but none of the latter patients included in the study died. KMT2A rearrangements were not associated with poorer prognosis.

CONCLUSION

In the largest cohort to date, our study describes the characteristics of infants with cutaneous involvement of myeloid neoplasms including cytomolecular findings and survival rates. Further prospective biologic and clinical studies of these infants with myeloid neoplasms will be required to individualize therapy for this rare patient population.

INSPIRED Symposium Part 4B: Chimeric Antigen Receptor T Cell Correlative Studies-Established Findings and Future Priorities

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of B cell malignancies, with multiple CAR T cell products approved for numerous indications by regulatory agencies worldwide. However, significant work remains to be done to enhance these treatments. In March 2023, a group of experts in CAR T cell therapy assembled at the National Institutes of Health in Bethesda, Maryland at the Insights in Pediatric CAR T Cell Immunotherapy: Recent Advances and Future Directions (INSPIRED) Symposium to identify key areas for research for the coming years. In session 4B, correlative studies to be incorporated into future clinical trials and real-world settings were discussed. Active areas of research identified included (1) optimizing CAR T cell product manufacturing; (2) ensuring adequate lymphodepletion prior to CAR T cell administration; (3) overcoming immunoregulatory cells and tumor stroma present in the tumor microenvironment, particularly in solid tumors; (4) understanding tumor intrinsic properties that lead to CAR T cell immunotherapy resistance; and (5) uncovering biomarkers predictive of treatment resistance, treatment durability, or immune-related adverse events. Here we review the results of previously published clinical trials and real-world studies to summarize what is currently known about each of these topics. We then outline priorities for future research that we believe will be important for improving our understanding of CAR T cell therapy and ultimately leading to better outcomes for patients.

Differentiation between rebound thymic hyperplasia and thymic relapse after chemotherapy in pediatric Hodgkin lymphoma

BACKGROUND

Rebound thymic hyperplasia (RTH) is a common phenomenon caused by stress factors such as chemotherapy (CTX) or radiotherapy, with an incidence between 44% and 67.7% in pediatric lymphoma. Misinterpretation of RTH and thymic lymphoma relapse (LR) may lead to unnecessary diagnostic procedures including invasive biopsies or treatment intensification. The aim of this study was to identify parameters that differentiate between RTH and thymic LR in the anterior mediastinum.

METHODS

After completion of CTX, we analyzed computed tomographies (CTs) and magnetic resonance images (MRIs) of 291 patients with classical Hodgkin lymphoma (CHL) and adequate imaging available from the European Network for Pediatric Hodgkin lymphoma C1 trial. In all patients with biopsy-proven LR, an additional fluorodeoxyglucose (FDG)-positron emission tomography (PET)-CT was assessed. Structure and morphologic configuration in addition to calcifications and presence of multiple masses in the thymic region and signs of extrathymic LR were evaluated.

RESULTS

After CTX, a significant volume increase of new or growing masses in the thymic space occurred in 133 of 291 patients. Without biopsy, only 98 patients could be identified as RTH or LR. No single finding related to thymic regrowth allowed differentiation between RTH and LR. However, the vast majority of cases with thymic LR presented with additional increasing tumor masses (33/34). All RTH patients (64/64) presented with isolated thymic growth.

CONCLUSION

Isolated thymic LR is very uncommon. CHL relapse should be suspected when increasing tumor masses are present in distant sites outside of the thymic area. Conversely, if regrowth of lymphoma in other sites can be excluded, isolated thymic mass after CTX likely represents RTH.

How should childhood acute lymphoblastic leukemia relapses in low-income and middle-income countries be managed: The AHOPCA-ALL study group experience

BACKGROUND

Children with relapsed acute lymphoblastic leukemia (ALL) in low-income and middle-income countries rarely survive. The Pediatric Hematology-Oncology Association of Central America (AHOPCA) developed the AHOPCA-ALL REC 2014 protocol to improve outcomes in resource-constrained settings without access to stem cell transplantation.

METHODS

The AHOPCA-ALL REC 2014 protocol was based on a modified frontline induction phase 1A, a consolidation therapy with six modified R-blocks derived from the ALL-Berlin-Frankfurt-Munster REZ 2002 protocol and intermittent maintenance therapy. Children with B-lineage ALL were eligible after a late medullary relapse, an early or late combined relapse, or any extramedullary relapses. Those with T-lineage ALL were eligible after early and late extramedullary relapses, as were those with both B-lineage and T-lineage relapses occurring at least 3 months after therapy abandonment.

RESULTS

The study population included 190 patients with T-lineage (n = 3) and B-lineage (n = 187) ALL. Of those with B-lineage ALL, 25 patients had a very early extramedullary relapse, 40 had an early relapse (32 extramedullary and 8 combined), and 125 had a late relapse (34 extramedullary, 19 combined, and 72 medullary). The main cause of treatment failure was second relapse (52.1%). The 3-year event-free survival rate (± standard error) was 25.9% ± 3.5%, and the 3-year overall survival rate was 36.7% ± 3.8%. The 3-year event-free survival rate was 47.2% ± 4.7% for late relapses. The most frequently reported toxicity was grade 3 or 4 infection. Mortality during treatment occurred in 17 patients (8.9%), in most cases because of infectious complications.

CONCLUSIONS

Selected children with relapsed ALL in Central America can be cured with second-line regimens even without access to consolidation with stem cell transplantation. Children in low-income and middle-income countries who have lower risk relapses of ALL should be treated with curative intent.

Response-adapted omission of radiotherapy in children and adolescents with early-stage classical Hodgkin lymphoma and an adequate response to vincristine, etoposide, prednisone, and doxorubicin (EuroNet-PHL-C1): a titration study

BACKGROUND

Children and adolescents with early-stage classical Hodgkin lymphoma have a 5-year event-free survival of 90% or more with vincristine, etoposide, prednisone, and doxorubicin (OEPA) plus radiotherapy, but late complications of treatment affect survival and quality of life. We investigated whether radiotherapy can be omitted in patients with adequate morphological and metabolic responses to OEPA.

METHODS

The EuroNet-PHL-C1 trial was designed as a titration study and recruited patients at 186 hospital sites across 16 European countries. Children and adolescents with newly diagnosed stage IA, IB, and IIA classical Hodgkin lymphoma younger than 18 years of age were assigned to treatment group 1 to be treated with two cycles of OEPA (vincristine 1·5 mg/m2 intravenously, capped at 2 mg, on days 1, 8, and 15; etoposide 125 mg/m2 intravenously, on days 1-5; prednisone 60 mg/m2 orally on days 1-15; and doxorubicin 40 mg/m2 intravenously on days 1 and 15). If no adequate response (a partial morphological remission or greater and PET negativity) had been achieved after two cycles of OEPA, involved-field radiotherapy was administered at a total dose of 19·8 Gy (usually in 11 fractions of 1·8 Gy per day). The primary endpoint was event-free survival. The primary objective was maintaining a 5-year event-free survival rate of 90% in patients with an adequate response to OEPA without radiotherapy. We performed intention-to-treat and per-protocol analyses. The trial was registered at ClinicalTrials.gov (NCT00433459) and with EUDRACT, (2006-000995-33) and is completed.

FINDINGS

Between Jan 31, 2007, and Jan 30, 2013, 2131 patients were registered and 2102 patients were enrolled onto EuroNet-PHL-C1. Of these 2102 patients, 738 with early-stage disease were allocated to treatment group 1. Median follow-up was 63·3 months (IQR 60·1-69·8). We report on 714 patients assigned to and treated on treatment group 1; the intention-to-treat population comprised 713 patients with 323 (45%) male and 390 (55%) female patients. In 440 of 713 patients in the intention-to-treat group who had an adequate response and did not receive radiotherapy, 5-year event-free survival was 86·5% (95% CI 83·3-89·8), which was less than the 90% target rate. In 273 patients with an inadequate response who received radiotherapy, 5-year event-free survival was 88·6% (95% CI 84·8-92·5), for which the 95% CI included the 90% target rate. The most common grade 3-4 adverse events were neutropenia (in 597 [88%] of 680 patients) and leukopenia (437 [61%] of 712). There were no treatment-related deaths.

INTERPRETATION

On the basis of all the evidence, radiotherapy could be omitted in patients with early-stage classical Hodgkin lymphoma and an adequate response to OEPA, but patients with risk factors might need more intensive treatment.

FUNDING

Deutsche Krebshilfe, Elternverein für Krebs-und leukämiekranke Kinder, Gießen, Kinderkrebsstiftung Mainz of the Journal Oldtimer Markt, Tour der Hoffnung, Menschen für Kinder, Mitteldeutsche Kinderkrebsforschung, Programme Hospitalier de Recherche Clinique, and Cancer Research UK.

[Precision medicine in the treatment of pediatric cancers]

Despite the progress in cure rates for pediatric cancers, several challenges remain, such as the management of diseases with poor prognosis. The efficacy of intensified chemotherapies is also accompanied by increased risks of severe acute and chronic toxicities. Thus, therapies specifically targeting tumor cells, or inhibiting oncogenic molecular aberrations, could provide more effective and less toxic treatments for pediatric cancers. Personalization of chemotherapies through pharmacogenetics and precision dosing could also improve the efficacy and toxicity of chemotherapies. In this review, we describe precision medicine strategies implemented or undergoing clinical evaluation in the treatment of pediatric cancers.

Cancer medicines on the WHO Model List of Essential Medicines: processes, challenges, and a way forward

The selection of cancer medicines for national procurement requires deliberate evaluation of population benefit, budget impact, sustainability, and health system capacity. However, this process is complicated by numerous challenges, including the large volume and rapid pace of newly developed therapies offering marginal gains at prohibitively high prices. The WHO Model List of Essential Medicines (EML) and Model List of Essential Medicines for Children (EMLc) have undergone a series of evidence-based updates to ensure recommended cancer medicines offer meaningful clinical benefit. This Health Policy paper describes how cancer medicines are listed on the EML and EMLc, including two updated WHO processes: (1) the formation of the Cancer Medicines Working Group, and (2) additional selection principles for recommending cancer medicines, including a minimum overall survival benefit of 4-6 months with improvement to quality of life compared with standard treatment. These updates, along with proposals to include formal price considerations, additional selection criteria, and multisectoral collaboration (eg, voluntary licensing) promote procurement of high-value essential cancer medicines on national formularies in the context of supporting sustainable health systems to achieve universal health coverage.

Near-tetraploid T-cell acute lymphoblastic leukaemia in childhood: Results of the AIEOP-BFM ALL studies

BACKGROUND

Near-tetraploidy-defined by DNA index 1.79-2.28 or 81-103 chromosomes-is a rare cytogenetic abnormality observed both in children and adults with T-cell acute lymphoblastic leukaemia (T-ALL) and its prognostic value is not yet determined.

PATIENTS AND METHODS

We report a retrospective study conducted in paediatric patients with newly diagnosed T-ALL treated in AIEOP-BFM ALL 2000 and 2009 studies. 31 near-tetraploid T-ALL patients (1.4%) are compared to T-ALL patients without near-tetraploidy.

RESULTS

Near-tetraploid karyotype was associated with lower frequency of high-risk features: white blood cells count at diagnosis ≥100,000/μL (19.3% versus 41.0%, p-value < 0.001), PPR (13.3% versus 35.8%, p-value = 0.01) and minimal residual disease high-risk at the end of consolidation phase Induction B (4.03% versus 14.6%, p-value = 0.001). Complete remission was achieved at the end of induction phase (day 33) in 100% near-tetraploid T-ALL patients, compared to 93.2% T-ALL without near-tetraploidy.

CONCLUSION

Overall, we found that near-tetraploid T-ALL in newly diagnosed paediatric patients is associated with low-risk presenting features, with favourable treatment response and outcome.

Modified Manufacturing Process Modulates CD19CAR T-cell Engraftment Fitness and Leukemia-Free Survival in Pediatric and Young Adult Subjects

T cells modified to express a chimeric antigen receptor (CAR) targeting CD19 can induce potent and sustained responses in children with relapsed/refractory acute lymphoblastic leukemia (ALL). The durability of remission is related to the length of time the CAR T cells persist. Efforts to understand differences in persistence have focused on the CAR construct, in particular the costimulatory signaling module of the chimeric receptor. We previously reported a robust intent-to-treat product manufacturing success rate and remission induction rate in children and young adults with recurrent/refractory B-ALL using the SCRI-CAR19v1 product, a second-generation CD19-specific CAR with 4-1BB costimulation coexpressed with the EGFRt cell-surface tag (NCT02028455). Following completion of the phase I study, two changes to CAR T-cell manufacturing were introduced: switching the T-cell activation reagent and omitting midculture EGFRt immunomagnetic selection. We tested the modified manufacturing process and resulting product, designated SCRI-CAR19v2, in a cohort of 21 subjects on the phase II arm of the trial. Here, we describe the unanticipated enhancement in product performance resulting in prolonged persistence and B-cell aplasia and improved leukemia-free survival with SCRI-CAR19v2 as compared with SCRI-CAR19v1.

Utilizing the prognostic impact of minimal residual disease in treatment decisions for pediatric acute lymphoblastic leukemia

INTRODUCTION

Acute lymphoblastic leukemia (ALL) is the first pediatric cancer where the assessment of early response to therapy by minimal residual disease (MRD) monitoring has demonstrated its importance to improve risk-based treatment approaches. The most standardized tools to study MRD in ALL are multiparametric flow cytometry and realtime-quantitative polymerase chain reaction amplification-based methods. In recent years, MRD measurement has reached greater levels of sensitivity and standardization through international laboratory networks collaboration.

AREAS COVERED

We herewith describe how to assess and apply the prognostic impact of MRD in treatment decisions, with specific focus on pediatric ALL. We also highlight the role of MRD monitoring in the context of genetically homogeneous subgroups of pediatric ALL. However, some queries remain to be addressed and emerging technologies hold the promise of improving MRD detection in ALL patients.

EXPERT OPINION

Emerging technologies, like next generation flow cytometry, droplet digital PCR, and next generation sequencing appear to be important methods for assessing MRD in pediatric ALL. These more specific and/or sensitive MRD monitoring methods may help to predict relapse with greater accuracy, and are currently being used in clinical trials to improve pediatric ALL outcome by optimizing patient stratification and earlier MRD-based interventional therapy.

Are clinical pharmacology studies still needed in childhood acute lymphoblastic leukemia?

Not available.

Assessment of Waldeyer's ring in pediatric and adolescent Hodgkin lymphoma patients-Importance of multimodality imaging: Results from the EuroNet-PHL-C1 trial

BACKGROUND

In the EuroNet Pediatric Hodgkin Lymphoma (EuroNet-PHL) trials, decision on Waldeyer's ring (WR) involvement is usually based on clinical assessment, that is, physical examination and/or nasopharyngoscopy. However, clinical assessment only evaluates mucosal surface and is prone to interobserver variability. Modern cross-sectional imaging technology may provide valuable information beyond mucosal surface, which may lead to a more accurate WR staging.

PATIENTS, MATERIALS, AND METHODS

The EuroNet-PHL-C1 trial recruited 2102 patients, of which 1752 underwent central review including reference reading of their cross-sectional imaging data. In 14 of 1752 patients, WR was considered involved according to clinical assessment. In these 14 patients, the WR was re-assessed by applying an imaging-based algorithm considering information from ¹⁸ F-fluorodeoxyglucose positron emission tomography, contrast-enhanced computed tomography, and/or magnetic resonance imaging. For verification purposes, the imaging-based algorithm was applied to 100 consecutive patients whose WR was inconspicuous on clinical assessment.

RESULTS

The imaging-based algorithm confirmed WR involvement only in four of the 14 patients. Of the remaining 10 patients, four had retropharyngeal lymph node involvement and six an inconspicuous WR. Applying the imaging-based algorithm to 100 consecutive patients with physiological appearance of their WR on clinical assessment, absence of WR involvement could be confirmed in 99. However, suspicion of WR involvement was raised in one patient.

CONCLUSIONS

The imaging-based algorithm was feasible and easily applicable at initial staging of young patients with Hodgkin lymphoma. It increased the accuracy of WR staging, which may contribute to a more individualized treatment in the future.

Second malignant neoplasms after treatment of non-Hodgkin's lymphoma-a retrospective multinational study of 189 children and adolescents

Data on the spectrum of second malignant neoplasms (SMNs) after primary childhood non-Hodgkin's lymphoma (NHL) are scarce. One-hundred-and-eighty-nine NHL patients diagnosed in a 30 years period of 1980-2010 developing an SMN were retrieved from 19 members of the European Intergroup for Childhood NHL and/or the international Berlin-Frankfurt-Münster Study Group. Five subgroups of SMNs were identified: (1) myeloid neoplasms (n = 43; 23%), (2) lymphoid neoplasms (n = 51; 27%), (3) carcinomas (n = 48; 25%), (4) central nervous system (CNS) tumors (n = 19; 10%), and (5) "other" SMNs (n = 28; 15%). In 37 patients (20%) preexisting disorders were reported with 90% having any kind of cancer predisposition syndrome (CPS). For the 189 primary NHL patients, 5-year overall survival (OS) after diagnosis of an SMN was 56 ± 4%, being worst for patients with preexisting disorders at 28 ± 8%. Five-year OS rates were 38 ± 8%, 59 ± 7%, 79 ± 8%, 34 ± 12%, and 62 ± 11%, respectively, for patients with myeloid and lymphoid neoplasms, carcinomas, CNS tumors, and "other" SMNs (p < 0.0001). Patients with SMNs after childhood NHL having a reported CPS, mostly mismatch repair disorders, carried a very poor prognosis. Moreover, although outcome was favorable in some subtypes of SMNs after childhood NHL (carcinomas, lymphoid neoplasms), other SMNs such as myeloid neoplasms and CNS tumors had a dismal prognosis.

Comparison of Interim PET Response to Second-Line Versus First-Line Treatment in Classic Hodgkin Lymphoma: Contribution to the Development of Response Criteria for Relapsed or Progressive Disease

In first-line treatment of Hodgkin lymphoma (HL), Deauville scores 1-3 define complete metabolic remission. Interim ¹⁸F-FDG PET is also used for relapse-treatment adaptation; however, PET response criteria are not validated for relapse treatment. Methods: We performed a pairwise comparative analysis of early response to first- and second-line treatments in 127 patients with classic HL who experienced relapse. The patients participated in the prospective, multicenter EuroNet-PHL-C1 study. Residual uptake was measured retrospectively using the qPET method, a validated semiautomatic quantitative extension of the Deauville score. Empiric cumulative distribution functions of the qPET values were used to systematically analyze the response to first- and second-line treatments. Results: Individual patients responded variably to first- and second-line treatments. However, the empiric cumulative distribution functions of the qPET values from all patients were nearly superimposable. Conclusion: The findings support that first- and second-line treatments in HL do not require different response criteria.

Preemptive mitigation of CD19 CAR T-cell cytokine release syndrome without attenuation of antileukemic efficacy

Immunotherapy with the adoptive transfer of T cells redirected with CD19-specific chimeric antigen receptors (CARs) for B-lineage acute lymphoblastic leukemia (ALL) can salvage >80% of patients having relapsed/refractory disease. The therapeutic index of this emerging modality is attenuated by the occurrence of immunologic toxicity syndromes that occur upon CAR T-cell engraftment. Here, we report on the low incidence of severe cytokine release syndrome (CRS) in a subject treated with a CAR T-cell product composed of a defined ratio CD4:CD8 T-cell composition with a 4-1BB:zeta CAR targeting CD19 who also recieved early intervention treatment. We report that early intervention with tocilizumab and/or corticosteroids may reduce the frequency at which subjects transition from mild CRS to severe CRS. Although early intervention doubled the numbers of subjects dosed with tocilizumab and/or corticosteroids, there was no apparent detrimental effect on minimal residual disease-negative complete remission rates or subsequent persistence of functional CAR T cells compared with subjects who did not receive intervention. Moreover, early intervention therapy did not increase the proportion of subjects who experience neurotoxicity or place subjects at risk for infectious sequelae. These data support the contention that early intervention with tocilizumab and/or corticosteroids in subjects with early signs of CRS is without negative impact on the antitumor potency of CD19 CAR T cells. This intervention serves to enhance the therapeutic index in relapsed/refractory patients and provides the rationale to apply CAR T-cell therapy more broadly in ALL therapy. This trial was registered at www.clinicaltrials.gov as #NCT020284.

[Recent advances and future directions in CAR-T cell therapy in pediatric oncology]

Fighting leukemia using the immune system (antibodies, lymphocytes) is an old idea, which has already been fulfilled in allogeneic bone marrow transplantation. Indeed, the effectiveness of the transplant depends on the action of the donor lymphocytes. To limit the adverse effects on bystander organs (graft-versus-host disease), autologous T cells can be engineered to express synthetic chimeric antigen receptors (CARs) with artificially redirected antigen specificity. Autologous T cells engineered to express a CAR targeting CD19 have shown unprecedented efficacy in clinical trials for relapsed/refractory B-cell leukemias and lymphomas. In this review article, we describe the therapeutic strategies, clinical trial results, side effects and future direction of CAR T cell therapy in B cell acute lymphoblastic leukemia and other pediatric cancers and its future role in the Swiss setting.

Genetic risk factors for VIPN in childhood acute lymphoblastic leukemia patients identified using whole-exome sequencing

AIM

To identify genetic markers associated with vincristine-induced peripheral neuropathy (VIPN) in childhood acute lymphoblastic leukemia.

PATIENTS & METHODS

Whole-exome sequencing data were combined with exome-wide association study to identify predicted-functional germline variants associated with high-grade VIPN. Genotyping was then performed for top-ranked signals (n = 237), followed by validation in independent replication group (n = 405).

RESULTS

Minor alleles of rs2781377/SYNE2 (p = 0.01) and rs10513762/MRPL47 (p = 0.01) showed increased risk, whereas that of rs3803357/BAHD1 had a protective effect (p = 0.007). Using a genetic model based on weighted genetic risk scores, an additive effect of combining these loci was observed (p = 0.003). The addition of rs1135989/ACTG1 further enhanced model performance (p = 0.0001).

CONCLUSION

Variants in SYNE2, MRPL47 and BAHD1 genes are putative new risk factors for VIPN in childhood acute lymphoblastic leukemia.

Whole-exome sequencing identified genetic risk factors for asparaginase-related complications in childhood ALL patients

Allergy, pancreatitis and thrombosis are common side-effects of childhood acute lymphoblastic leukemia (ALL) treatment that are associated with the use of asparaginase (ASNase), a key component in most ALL treatment protocols. Starting with predicted functional germline variants obtained through whole-exome sequencing (WES) data of the Quebec childhood ALL cohort we performed exome-wide association studies with ASNase-related toxicities. A subset of top-ranking variants was further confirmed by genotyping (N=302) followed by validation in an independent replication group (N=282); except for thrombosis which was not available for that dataset. SNPs in 12 genes were associated with ASNase complications in discovery cohort including 3 that were associated with allergy, 3 with pancreatitis and 6 with thrombosis. The risk was further increased through combined SNPs effect (p≤0.002), suggesting synergistic interactions between the SNPs identified in each of the studied toxicities. Interestingly, rs3809849 in the MYBBP1A gene was associated with allergy (p= 0.0006), pancreatitis (p=0.002), thrombosis (p=0.02), event-free survival (p=0.02) and overall survival (p=0.003). Furthermore, rs11556218 in IL16 and rs34708521 in SPEF2 were both associated with thrombosis (p=0.01 and p=0.03, respectively) and pancreatitis (p=0.02). The association of SNPs in MYBBP1A, SPEF2 and IL16 geneswith pancreatitis was replicated in the validation cohort (p ≤0.05) as well as in combined cohort (p=0.0003, p=0.008 and p=0.02, respectively). The synergistic effect of combining risk loci had the highest power to predict the development of pancreatitis in both cohorts and was further potentiated in the combined cohort (p=1×10^-8). The present work demonstrates that using WES data is a successful “hypothesis-free” strategy for identifying significant genetic markers modulating the effect of the treatment in childhood ALL.

Lymphocyte apheresis for chimeric antigen receptor T-cell manufacturing in children and young adults with leukemia and neuroblastoma

BACKGROUND

The first step in the production of chimeric antigen receptor T cells is the collection of autologous T cells using apheresis technology. The procedure is technically challenging, because patients often have low leukocyte counts and are heavily pretreated with multiple lines of chemotherapy, marrow transplantation, and/or radiotherapy. Here, we report our experience of collecting T lymphocytes for chimeric antigen receptor T-cell manufacturing in pediatric and young adult patients with leukemia, non-Hodgkin lymphoma, or neuroblastoma.

STUDY DESIGN AND METHODS

Apheresis procedures were performed on a COBE Spectra machine using the mononuclear cell program, with a collection target of 1 × 10⁹ total mononuclear cells per kilogram. Data were collected regarding preapheresis and postapheresis blood counts, apheresis parameters, products, and adverse events.

RESULTS

Ninety-nine patients (ages 1.3-25.7 years) and 102 apheresis events were available for analysis. Patients underwent apheresis at a variety of absolute lymphocyte cell counts, with a median absolute lymphocyte count of 944 cells/μL (range, 142-6944 cells/μL). Twenty-two patients (21.6%) had absolute lymphocyte counts less than 500 cells/μL. The mononuclear cell target was obtained in 100% of all apheresis harvests, and chimeric antigen receptor T-cell production was possible from the majority of collections (94%). Mononuclear cell collection efficiency was 65.4%, and T-lymphocyte collection efficiency was 83.4%. Ten patients (9.8%) presented with minor adverse events during the 102 apheresis procedures, with one exception of a severe allergy.

CONCLUSIONS

Mononuclear cell apheresis for chimeric antigen receptor T-cell therapy is well tolerated and safe, and it is possible to obtain an adequate quantity of CD3+ lymphocytes for chimeric antigen receptor T-cell manufacturing in heavily pretreated patients who have low lymphocyte counts.

The Evolution and Future of CAR T Cells for B-Cell Acute Lymphoblastic Leukemia

Several CAR T designs with CD19 specificity have been associated with consistent responses in clinical trials with complete remission (CR) rates ranging from 70-90%. Relevant challenges remain to be addressed, such as production time, early loss of CAR T cells, relapse due to loss of the target antigen, and prevention of severe cytokine release syndrome and neurotoxicity. This review describes constructs, clinical trial results, side effects, and future direction of CAR T-cell therapy in B-ALL.

DNA variants in DHFR gene and response to treatment in children with childhood B ALL: revisited in AIEOP-BFM protocol

AIM

We have previously reported an association of dihydrofolate reductase promoter polymorphisms with reduced event-free survival in childhood acute lymphoblastic leukemia (ALL) patients treated with Dana Farber Cancer Institute protocol. Here, we assessed whether these associations are applicable to other protocol, based on different methotrexate doses.

METHODS

Genotypes for six tag polymorphisms and resulting haplotypes were analyzed for an association with ALL outcome.

RESULTS

The association was found with the polymorphisms A-680C, A-317G and C-35T in high-risk group patients. Carriers of haplotype *1 had a remarkably higher risk of events compared with noncarriers and a lower probability of event-free survival (21.4 vs 81.3%).

CONCLUSION

The role of DHFR variants in predicting the outcome of childhood ALL extends beyond single-treatment protocol and can be useful biomarker in personalizing treatment.

Opportunities and challenges in the immunological therapy of pediatric malignancy: a concise snapshot

Over the last 50 years, collaborative clinical trials have reduced the number of children dying from pediatric cancer significantly. Unfortunately, certain tumor types have remained resistant to conventional surgical, radiotherapy and chemotherapy combinations, and relapsing and/or refractory disease remains associated with dismal outcomes. Recently, renewed attention has been given to the role for immunotherapies in pediatric oncology. In fact, these combine several attractive features, including (but possibly not limited to) the specificity for cancer cells, potentially in vivo persistence and longevity, and potency against refractory disease. In this narrative review designed for the academic pediatrician, we will concisely review the biological underpinnings behind the immunological therapy of pediatric neoplasms and illustrate the current humoral, cellular approaches, and novel drugs targeting the immune checkpoint, oncolytic viruses, and tumor vaccines. We will also comment on the future directions, challenges, and open questions faced by the field. What is Known: • Cancer immunotherapy drives immune cells and its humoral weaponry to eliminate tumor cells. • This occurs by recognizing antigens ideally expressed only on tumoral, but not normal/healthy, cells. What is New: • Clinical immunotherapy trials have shown responses in children with relapsing/refractory neoplasms. • Novel humoral/cellular immunotherapies, immune checkpoint inhibitors, oncolytic viruses, and tumor vaccines are currently being investigated in pediatric oncology.

Primary Cutaneous Lymphomas in Children and Adolescents

Primary cutaneous lymphomas are rare in children and mostly represented by mycosis fungoides and CD30(+) lymphoproliferative disorders. Most pediatric cutaneous lymphomas have similar clinical/pathological features as their adult counterparts, particularly the T-cell subtypes. With regard to outcome, adult cutaneous mature T-cell lymphomas have a tendency to progression, while this appears to be relatively infrequent in children. The outcome of cutaneous B-cell lymphomas depends on subtype, with the B-lymphoblastic entity being associated with similar outcomes to precursor B acute lymphoblastic leukemia, while there are insufficient data on other entities. The diagnosis and treatment of these patients require a close collaboration between experienced pediatric pathologists, dermatologists, and oncologists. Prospective collection of longitudinal clinical and biological data from children with these rare lymphomas is needed to better understand their biological and clinical behavior and to ultimately discover the best therapeutic strategies.

Clinical presentation and risk factors of serious infections in children with Down syndrome treated for acute lymphoblastic leukemia

BACKGROUND

Treatment of acute lymphoblastic leukemia (ALL) in children with Down syndrome (DS) is associated with a higher incidence of life-threatening infections compared to the overall pediatric population. The objective of this study was to describe infections and identify risk factors of microbiologically documented infections at a sterile site in children with DS during chemotherapy for ALL.

PROCEDURE

We conducted a single-institution retrospective review of infectious episodes encountered by patients with DS during primary treatment for ALL. Correlations between features of clinical presentation and severity of microbiologically proven infections were investigated.

RESULTS

Among 237 suspected infectious episodes encountered by 35 patients with DS and ALL (DS-ALL), a total of 40 episodes (16.9%) had the clinical presentation of a severe infection (SI). Seventeen patients had 33 (13.9%) microbiologically proven infections from a sterile site. Fever was not part of the clinical presentation in 27% of microbiologically documented infectious episodes. The odds ratio of a microbiologically proven infection at a sterile site was significantly increased during a 7-day interval after treatment with glucocorticoids (2.18; 95% CI: 1.02-4.66; P = 0.04). Neither administration of anthracyclines in the preceding 14 days nor neutropenia correlated with infections.

CONCLUSIONS

Serious infections in DS-ALL may present without typical signs such as fever. The immediate time period following administration of glucocorticoids is particularly associated with the risk of SIs.

Improvement of the Outcome of Relapsed or Refractory Acute Lymphoblastic Leukemia in Children Using a Risk-Based Treatment Strategy

Relapsed/refractory acute lymphoblastic leukemia (ALL) is a leading cause of death by cancer in children. Our institution has switched relapse treatment strategy to improve survival. We reviewed records of first relapse/refractory childhood ALL between 1996 and 2012. Based on length of first remission, relapse site and immunophenotype, patients were classified into two groups: standard-risk relapse (SRR) and high-risk relapse and refractory (HRRR). Before 2007, all patients were uniformly treated with the same induction as at presentation, followed by hematopoietic stem cell transplantation (HSCT). Since 2007, treatment was given according to risk of failure: SRR were mostly treated with chemotherapy; HRRR patients underwent HSCT after intensive chemotherapy, aiming reduction of pre-transplant disease burden. Sixty-four patients were included. Thirty (47%) were SRR and 34 (53%) HRRR, including 11 with refractory ALL. Five-years overall survival (OS) and event-free survival (EFS) were similar for SRR, but were significantly higher with new risk-based strategy for HRRR: 56% versus 17% (P = 0.03) for OS, and 56% vs 11% for EFS (P = 0.008), respectively. In multivariate analysis, treatment strategy was significantly associated with survival. In conclusion, change for a risk-based strategy in our institution increased survival of high-risk patients to levels similar of those of standard-risk patients.

Safety and efficacy of intrathecal rituximab in children with B cell lymphoid CD20+ malignancies: An international retrospective study

Central nervous system (CNS) involvement in patients with mature B non-Hodgkin lymphoma, post-transplantation proliferative disorder and acute lymphoblastic leukemia confers a significantly inferior prognosis as compared to patients without CNS disease. Intrathecal (IT) or intraventricular administration of rituximab is an option for this group of patients. We report 25 children with CNS involvement of CD20+ B lymphoid malignancies who received in total 163 IT/intraventricular rituximab doses. The median number of doses received by each patient was 6, with a median dose of 25 mg. The most common adverse events were Grades 1 and 2 peripheral neuropathies in five patients (20%), allergy in two patients, and headache in two patients. These events were self-limited, occurring in the 48 hours after treatment and resolving within 24 hr. Three patients presented with more severe though transient side effects, one with a Grade III neuropathy and two with seizure. Eighteen patients (72%) of those treated with IT/intraventricular rituximab, with or without other CNS directed treatment, achieved a CNS remission. This case series suggests that IT/intraventricular rituximab has therapeutic efficacy and relatively limited toxicity. Prospective trials of IT/intraventricular rituximab for patients with CNS involvement of CD20 + B lymphoid malignancies are warranted.

Anaplastic Large Cell Lymphoma in Central America: A Report From the Central American Association of Pediatric Hematology Oncology (AHOPCA)

BACKGROUND

Although anaplastic large cell lymphoma (ALCL) is curable in high-income countries (HIC), data from low- and middle-income countries (LMIC) are lacking. We therefore conducted a retrospective study of the Central American Association of Pediatric Hematology Oncology (AHOPCA) experience in treating ALCL.

PROCEDURE

We included all patients age <18 years newly diagnosed with ALCL treated between 2000 and 2013 in seven AHOPCA institutions. Retrospective data were extracted from the Pediatric Oncology Network Database.

RESULTS

Thirty-one patients met inclusion criteria. Twenty-five (81%) had advanced disease (stages III and IV), six (19%) were treated on the APO (doxorubicin, prednisone, vincristine) regimen, 15 (49%) on multi-agent chemotherapy designed for T-cell lineage malignancies (GuatALCL protocol), and 10 (32%) on BFM-based treatment regimens. Five-year overall event-free survival and overall survival were, respectively, 67.1 ± 8.6% and 66.7 ± 8.7%. All 10 events occurred in patients treated on BFM-based treatment regimens or the GuatALCL protocol, none on APO treatment: two patients experienced relapse, six treatment related mortality (TRM), and two abandonment.

CONCLUSIONS

Treatment of ALCL in countries with limited resources is feasible with similar outcomes as in HIC, though the causes of treatment failure differ. Less intensive regimens may be preferable in order to decrease TRM and improve outcomes. Prospective clinical trials determining the ideal treatment for LMIC children with ALCL are necessary.

Infectious complications in children with acute lymphoblastic leukemia treated in low-middle-income countries

Infections are the most important cause of morbidity and mortality in children treated for acute lymphoblastic leukemia (ALL). The rates of infection-associated mortality are up to 10-times higher in low- and middle-income countries (LMIC) than in high-income countries. The prevention, early recognition and management of infectious complications is especially challenging in LMIC because of disease and poverty-related factors, as well as the shortage of trained personnel, supplies, diagnostic tools and adequate organizational infrastructure. Children in LMIC with ALL, who are frequently underweight, are at increased risk of community-acquired pathogens, nosocomial multidrug-resistant pathogens and opportunistic microorganisms. This review summarizes the challenges of managing the major categories of infections in children receiving treatment for ALL and provides updated practical recommendations for preventing and managing these infections in LMIC.

Polymorphisms of the vincristine pathway and response to treatment in children with childhood acute lymphoblastic leukemia

BACKGROUND

Vincristine (VCR) is a standard component in the treatment of childhood acute lymphoblastic leukemia (ALL). VCR cytotoxicity is primarily due to its ability to disrupt the formation of microtubules of the mitotic spindle.

PATIENTS & METHODS

Seventeen polymorphisms in regulatory and coding regions of genes controlling VCR targets (TUBB1, MAP4, ACTG1 and CAPG) or potentially influencing VCR levels (ABCB1 and CYP3A5) were investigated for an association with peripheral neuropathy and outcome in childhood ALL patients.

RESULTS

High-grade neurotoxicity was more frequent in carriers of the A allele of synonymous (Ala310) G to A (rs1135989) variation in the ACTG1 gene. Substitution (rs4728709) in the promoter of the ABCB1 gene had a protective effect against lower grade neurotoxicity and C to A variation (rs3770102) located 17 nucleotides upstream from the transcription start site had a protective effect against high-grade neurotoxicity. Patients with the ABCB1 3435TT genotype had lower event-free survival; the association with event-free survival was not supported by the analysis in the replication patient set.

CONCLUSION

The polymorphisms in the ACTG1, CAPG and ABCB1 genes may modulate VCR-related neurotoxicity, whereas the risk of relapse seems not to be affected by the genes of the VCR pathway.

Risk factors for relapse in childhood acute lymphoblastic leukemia: prediction and prevention

With current treatment regimens, survival rates for acute lymphoblastic leukemia (ALL) have improved dramatically since the 1980s, with current 5-year overall survival rates estimated at greater than 85%. This success was achieved, in part, through the implementation of risk-stratified therapy. Nevertheless, for a subgroup of patients (15-20%) with newly diagnosed ALL who will ultimately relapse, traditional risk assessment remains inadequate. The risk of relapse may be estimated on the basis of diagnostic features or early treatment response findings. Further progress in this field may thus come from refinement of predictive factors for relapse and treatment adaptation and from the identification of biological subsets of ALL patients who could benefit from specific target therapies. This article summarizes the aspects associated with the identification of predictive factors for relapse in childhood ALL and options available for prevention of disease recurrence.

Polymorphisms of asparaginase pathway and asparaginase-related complications in children with acute lymphoblastic leukemia

PURPOSE

Asparaginase (ASNase) is a standard and critical component in the therapy of childhood acute lymphoblastic leukemia (ALL), but it is also associated with several toxicities.

EXPERIMENTAL DESIGN

We recently reported the results of an association study between ASNase pathway genes and event-free survival (EFS) in childhood patients with ALL. The same polymorphisms were interrogated here in relation to allergies, pancreatitis, and thrombotic events following treatment with E. coli ASNase.

RESULTS

Among patients of the discovery group, allergies, and pancreatitis were more frequent in individuals who are homozygous for the triple-repeat allele (3R) of the asparagine synthetase (ASNS) gene, resulting in remarkably higher risk of these toxicities associated with 3R3R genotype [OR for allergies, 14.6; 95% confidence interval (CI), 3.6-58.7; P < 0.0005 and OR for pancreatitis, 8.6; 95% CI, 2.0-37.3; P = 0.01]. In contrast, the ASNS haplotype *1 harboring double-repeat (2R) allele had protective effect against these adverse reactions (P ≤ 0.01). The same haplotype was previously reported to confer reduction in EFS. The risk effect of 3R3R genotype was not replicated in the validation cohort, whereas the protective effect of haplotype *1 against allergies was maintained (P ≤ 0.002). Analysis with additional polymorphisms in ASNS locus in lymphoblastoid cell lines showed that haplotype *1 is diversified in several subtypes of which one was associated with reduced in vitro sensitivity to ASNase (rs10486009, P = 0.01) possibly explaining an association seen in clinical setting.

CONCLUSIONS

This finding might have implication for treatment individualization in ALL and other cancers using asparagine depletion strategies. Clin Cancer Res; 21(2); 329-34. ©2014 AACR. See related commentary by Avramis, p. 230.

Bim polymorphisms: influence on function and response to treatment in children with acute lymphoblastic leukemia

PURPOSE

Corticosteroids induce apoptosis in the malignant lymphoid cells and are critical component of combination therapy for acute lymphoblastic leukemia (ALL). Several genome-wide microarray studies showed major implication of proapoptotic Bim in mediating corticosteroid-related resistance in leukemia cells.

EXPERIMENTAL DESIGN

We investigated Bim gene polymorphisms and their association with childhood ALL outcome, and the mechanism underlying the observed finding.

RESULTS

Lower overall survival (OS) was associated with Bim C29201T located in Bcl-2 homology 3 (BH3) domain (P = 0.01). An association remained significant in multivariate model (P = 0.007), was more apparent in high-risk patients (P = 0.004) and patients treated with dexamethasone (P = 0.009), and was subsequently confirmed in the replication patient cohort (P = 0.03). RNA analysis revealed that C29201T affects generation of γ isoforms (γ1) that lack proapoptotic BH3 domain. The phenotypic effect was minor suggesting the influence of additional factors that may act in conjunction with Bim genotype. Combined analysis with Mcl gene polymorphism (G-486T) revealed profound reduction in OS in individuals with both risk genotypes (P < 0.0005 in discovery and P = 0.002 in replication cohort) and particularly in high-risk patients (P ≤ 0.008).

CONCLUSIONS

Increased expression of prosurvival Mcl1 and presence of Bim isoforms lacking proapoptotic function might explain marked reduction of OS in a disease and dose-dependent manner in ALL patients carrying Bim- and Mcl1-risk genotypes.

Cytogenetic characterization of childhood acute lymphoblastic leukemia in Nicaragua

BACKGROUND

Within the frame of a twinning programme with Nicaragua, The La Mascota project, we evaluated in our study the contribution of cytogenetic characterization of acute lymphoblastic leukemia (ALL) as prognostic factor compared to clinical, morphological, and immunohistochemical parameters.

METHODS

All patients with ALL treated at the only cancer pediatric hospital in Nicaragua during 2006 were studied prospectively. Diagnostic immunophenotyping was performed locally and bone marrow or blood samples were sent to the cytogenetic laboratory of Zurich for fluorescence in situ hybridization (FISH) analysis and G-banding.

RESULTS

Sixty-six patients with ALL were evaluated. Their mean age at diagnosis was 7.3 years, 31.8% were >or=10 years. Thirty-four patients (51.5%) presented with hyperleucocytosis >or=50 x 10(9)/L, 45 (68.2%) had hepatosplenomegaly. Immunophenotypically 63/66 patients (95%) had a B-precursor, 2 (3%) a T- and 1 (1.5%) a B-mature ALL. FISH analysis demonstrated a TEL/AML1 fusion in 9/66 (14%), BCR/ABL fusion in 1 (1.5%), MLL rearrangement in 2 (3.1%), iAMP21 in 2 (3.1%), MYC rearrangement in 1 (1.5%), and high-hyperdiploidy in 16 (24%). All patients but two with TEL/AML1 fusion and high-hyperdiploidy were clinically and hematologically in the standard risk group whereas those with poor cytogenetic factors had clinical high-risk features and were treated intensively.

CONCLUSIONS

Compared to Europe, the ALL population in Nicaragua is older, has a higher proportion of poor prognostic clinical and hematological features and receives more intensive treatment, while patients with TEL/AML1 translocations and high-hyperdiploidy are clinically in the standard risk group. Cytogenetics did not contribute as an additional prognostic factor in this setting.