ATM germline pathogenic variants affect outcomes in children with ataxia-telangiectasia and hematological malignancies.

Ataxia-telangiectasia (A-T) is an autosomal-recessive disorder caused by pathogenic variants (PVs) of the ATM gene. Children with A-T are predisposed to hematological malignancies. We aimed to investigate their characteristics and outcomes in order to generate data-based treatment recommendations. In this multinational, observational study we report 202 patients aged ≤25 years with A-T and hematological malignancies from 25 countries. Ninety-one patients (45%) presented with mature B-cell lymphomas, 82 (41%) with acute lymphoblastic leukemia/lymphoma, 21(10%) with Hodgkin lymphoma and eight (4%) with other hematological malignancies. Four-year overall survival and event-free survival (EFS) were 50.8% (95% CI 43.6-59.1) and 47.9% (95% CI 40.8-56.2), respectively. Cure rates have not significantly improved over the last four decades (p=.76). The major cause of treatment failure was treatment-related mortality (TRM) with a four-year cumulative incidence of 25.9% (95% CI 19.5-32.4). Germline ATM PVs were categorized as null or hypomorphic and patients with available genetic data (n=110) were classified as having absent (n=81) or residual (n=29) ATM kinase activity. Four-year EFS was 39.4% (95% CI 29-53.3) vs 78.7% (95% CI 63.7-97.2), (p<.001), and TRM rates were 37.6% (95% CI 26.4-48.7) vs 4.0% (95% CI 0-11.8), (p=.017), for those with absent and residual ATM kinase activity, respectively. Absence of ATM kinase activity was independently associated with decreased EFS (HR=0.362, 95% CI 0.16-0.82; p=.009) and increased TRM (HR=14.11, 95% CI 1.36-146.31; p=.029). Patients with A-T and leukemia/lymphoma may benefit from de-escalated therapy for patients with absent ATM kinase activity and near-standard therapy regimens for those with residual kinase activity.

Gaucher Disease Type 2 Manifested as Hemophagocytic Lymphohistiocytosis in a Neonate in the COVID-19 Era.

BACKGROUND: A term neonate presented with persistent severe thrombocytopenia, elevated liver enzymes, conjugated hyperbilirubinemia, hepatosplenomegaly, and mild hypotonia. OBSERVATIONS: A thorough workup for infections, congenital thrombocytopenias, and neonatal malignancies was negative. Because of increased anti-SARS-CoV-2 IgG antibodies after maternal COVID-19, multisystem inflammatory syndrome of neonates was considered and intravenous immunoglobulin was administered. The clinical condition of the neonate deteriorated and due to laboratory evidence of hyperinflammation, hemophagocytic lymphohistiocytosis was suspected, and treatment with etoposide and dexamethasone was initiated with temporary stabilization. Gaucher disease type 2 was eventually diagnosed. CONCLUSION: Gaucher disease can rarely present in neonates as hemophagocytic lymphohistiocytosis.

Long-term outcome, clinical course and treatment approaches of paediatric langerhans cell histiocytosis: A greek reference centre report.

AIM: Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia with diverse clinical behaviour. In this article, we studied the clinical course, management and long-term outcomes of a paediatric cohort treated by our reference centre. METHODS: We retrospectively studied 66 children with LCH, consecutively diagnosed by a Greek reference centre from 1974 to 2020. RESULTS: The patients had a median age of 3.9 (range 0.0-15.9) years, 39 and 6 patients were diagnosed with unifocal or multifocal single system disease and 14 and 7 had multisystem disease with or without risk organ involvement. No late occurrence of clinical neurodegenerative disease or diabetes insipidus were observed at a median follow-up period of 4.1 (range 0.5-27.7) years. The 10-year event-free survival and overall survival were 65.0% and 90.3% and improved significantly over a 45-year period. Survival was superior in single system than multisystem cases. BRAF V600E mutation was found in 8/14 tested patients. Reactivation occurred in 12/66 patients (18.2%); 11 achieved remission and one patient died after a second relapse. CONCLUSION: LCH survival rates significantly increased in our cohort over time. Reactivation occurred in 18.2% patients, but no late neurodegeneration was found. The prognostic value of single system disease status vs. multisystem LCH was confirmed.

Interference of bone marrow CD56+ mesenchymal stromal cells in minimal residual disease investigation of neuroblastoma and other CD45- /CD56+ pediatric malignancies using flow cytometry.

BACKGROUND: Bone marrow (BM) samples obtained from minimal residual disease (MRD)-negative children with B-cell acute lymphoblastic leukemia (B-ALL) were used in our laboratory as negative biological controls for the development of a neuroblastoma (NBL) flow-cytometric (FC) protocol. The accidental, but systematic, identification of rare cell populations (RCP) mimicking NBL cells (CD45- /CD56+ ) in these samples indicated the need for their thorough immunophenotypic identification, in order to elucidate their possible interference in NBL-MRD assessment. PROCEDURE: RCP observed in BM samples from 14 children recovering from BM aplasia due to intensive chemotherapy for B-ALL were investigated with the following markers: CD81, CD200, CD24, GD2, CD73, CD13, CD90, CD146, CD9, CD117, CD10, CD99, and NG2. BM samples from six newly diagnosed patients with NBL and an NBL cell line were simultaneously investigated as positive controls. RESULTS: The frequency of RCP in B-ALL BM samples was < 1/1 × 104 cells (bulky lysis), and their immunophenotypic profile was indicative of CD56+ mesenchymal stromal cells (MSCs) (CD45- , CD90+ , CD146+ , CD73+ ). Also, RCP expressed CD81 and CD200, simulating NBL cells. The most useful discriminative markers for CD56+ MSCs were CD13 and CD73. An appropriate protocol consisting of two tubes with seven color combinations was further proposed: SYTO-16, GD2 (first tube) or CD73 (second tube)-PE, CD24-ECD, CD13-PC5.5, CD45-PC7, CD81-APC, and CD56-APC700. CONCLUSIONS: RCP that were immunophenotypically similar to NBL were identified as CD56+ MSCs. As these cells might pose an obstacle to accurate NBL disease assessment by FC, especially MRD, an enhanced NBL-FC protocol is proposed for prospective evaluation.

A prospective study on the epidemiology and clinical significance of viral respiratory infections among pediatric oncology patients.

Respiratory infections in oncology are both common and potentially severe. However, there is still a gap in the literature, regarding the epidemiology of viral respiratory infections in children with cancer. We prospectively enrolled 224 patients, from September 2012 to August 2015. The cohort included children with hematologic or solid malignancies receiving chemotherapy, or undergoing hemopoietic stem cell transplantation, outpatients/inpatients exhibiting signs/symptoms of febrile/afebrile upper/lower respiratory infection. Viral infection was diagnosed by detection of ≥1 viruses from a sample at time of enrollment, using the CLART® PneumoVir kit (GENOMICA, Spain). Α detailed questionnaire including demographics and medical history was also completed. Samples were processed in batches, results were communicated as soon as they became available. Children recruited in whom no virus was detected composed the no virus detected group. Viral prevalence was 38.4% in children presenting with respiratory illness. A single virus was found in 30.4%, with RSV being the most frequent. Viral coinfections were detected in 8%. Children with viral infection were more likely to be febrile upon enrollment and to present with lower respiratory signs/symptoms. They had longer duration of illness and they were more likely to receive antibiotics/antifungals. Only 22% of children with influenza received oseltamivir. Mortality was low (2.7%), however, pediatric intensive care unit (PICU) admission and death were correlated with virus detection. In our study mortality was low and PICU admission was related to virus identification. Further research is needed to clarify whether antibiotics in virus-proven infection are of value and underline the importance of oseltamivir's timely administration in influenza.

Neuroblastoma among children in Southern and Eastern European cancer registries: Variations in incidence and temporal trends compared to US.

Neuroblastoma comprises the most common neoplasm during infancy (first year of life). Our study describes incidence of neuroblastoma in Southern-Eastern Europe (SEE), including - for the first time - the Nationwide Registry for Childhood Hematological Malignancies and Solid Tumors (NARECHEM-ST)/Greece, compared to the US population, while controlling for human development index (HDI). Age-adjusted incidence rates (AIR) were calculated for 1,859 childhood (0-14 years) neuroblastoma cases, retrieved from 13 collaborating SEE registries (1990-2016), and were compared to those of SEER/US (N = 3,166; 1990-2012); temporal trends were assessed using Poisson regression and Joinpoint analyses. The overall AIR was significantly lower in SEE (10.1/million) compared to SEER (11.7 per million); the difference was maximum during infancy (43.7 vs. 53.3 per million, respectively), when approximately one-third of cases were diagnosed. Incidence rates of neuroblastoma at ages <1 and 1-4 years were positively associated with HDI, whereas lower median age at diagnosis was correlated with higher overall AIR. Distribution of primary site and histology was similar in SEE and SEER. Neuroblastoma was slightly more common among males compared to females (male-to-female ratio: 1.1), mainly among SEE infants. Incidence trends decreased in infants in Slovenia, Cyprus and SEER and increased in Ukraine and Belarus. The lower incidence in SEE compared to SEER, especially in infants living in low HDI countries possibly indicates a lower level of overdiagnosis in SEE. Hence, increases in incidence rates in infancy noted in some subpopulations should be carefully monitored to avoid the unnecessary costs health impacts of tumors that could potentially spontaneously regress.

Heterogeneous MYCN amplification in neuroblastoma: a SIOP Europe Neuroblastoma Study.

BACKGROUND: In neuroblastoma (NB), the most powerful prognostic marker, the MYCN amplification (MNA), occasionally shows intratumoural heterogeneity (ITH), i.e. coexistence of MYCN-amplified and non-MYCN-amplified tumour cell clones, called heterogeneous MNA (hetMNA). Prognostication and therapy allocation are still unsolved issues. METHODS: The SIOPEN Biology group analysed 99 hetMNA NBs focussing on the prognostic significance of MYCN ITH. RESULTS: Patients <18 months (18 m) showed a better outcome in all stages as compared to older patients (5-year OS in localised stages: <18 m: 0.95 ± 0.04, >18 m: 0.67 ± 0.14, p = 0.011; metastatic: <18 m: 0.76 ± 0.15, >18 m: 0.28 ± 0.09, p = 0.084). The genomic 'background', but not MNA clone sizes, correlated significantly with relapse frequency and OS. No relapses occurred in cases of only numerical chromosomal aberrations. Infiltrated bone marrows and relapse tumour cells mostly displayed no MNA. However, one stage 4s tumour with segmental chromosomal aberrations showed a homogeneous MNA in the relapse. CONCLUSIONS: This study provides a rationale for the necessary distinction between heterogeneous and homogeneous MNA. HetMNA tumours have to be evaluated individually, taking age, stage and, most importantly, genomic background into account to avoid unnecessary upgrading of risk/overtreatment, especially in infants, as well as in order to identify tumours prone to developing homogeneous MNA.

Risk stratification of high-risk metastatic neuroblastoma: A report from the HR-NBL-1/SIOPEN study.

BACKGROUND: Risk stratification is crucial to treatment decision-making in neuroblastoma. This study aimed to explore factors present at diagnosis affecting outcome in patients aged ≥18 months with metastatic neuroblastoma and to develop a simple risk score for prognostication. PROCEDURE: Data were derived from the European high-risk neuroblastoma 1 (HR-NBL1)/International Society for Paediatric Oncology European Neuroblastoma (SIOPEN) trial with analysis restricted to patients aged ≥18 months with metastatic disease and treated prior to the introduction of immunotherapy. Primary endpoint was 5-year event-free survival (EFS). Prognostic factors assessed were sex, age, tumour MYCN amplification (MNA) status, serum lactate dehydrogenase (LDH)/ferritin, primary tumour and metastatic sites. Factors significant in univariate analysis were incorporated into a multi-variable model and an additive scoring system developed based on estimated log-cumulative hazard ratios. RESULTS: The cohort included 1053 patients with median follow-up 5.5 years and EFS 27 ± 1%. In univariate analyses, age; serum LDH and ferritin; involvement of bone marrow, bone, liver or lung; and >1 metastatic system/compartment were associated with worse EFS. Tumour MNA was not associated with worse EFS. A multi-variable model and risk score incorporating age (>5 years, 2 points), serum LDH (>1250 U/L, 1 point) and number of metastatic systems (>1, 2 points) were developed. EFS was significantly correlated with risk score: EFS 52 ± 9% for score = 0 versus 6 ± 3% for score = 5 (P < 0.0001). CONCLUSIONS: A simple score can identify an "ultra-high risk" (UHR) cohort (score = 5) comprising 8% of patients with 5-year EFS <10%. These patients appear not to benefit from induction therapy and could potentially be directed earlier to alternative experimental therapies in future trials.

Busulfan and melphalan versus carboplatin, etoposide, and melphalan as high-dose chemotherapy for high-risk neuroblastoma (HR-NBL1/SIOPEN): an international, randomised, multi-arm, open-label, phase 3 trial.

BACKGROUND: High-dose chemotherapy with haemopoietic stem-cell rescue improves event-free survival in patients with high-risk neuroblastoma; however, which regimen has the greatest patient benefit has not been established. We aimed to assess event-free survival after high-dose chemotherapy with busulfan and melphalan compared with carboplatin, etoposide, and melphalan. METHODS: We did an international, randomised, multi-arm, open-label, phase 3 cooperative group clinical trial of patients with high-risk neuroblastoma at 128 institutions in 18 countries that included an open-label randomised arm in which high-dose chemotherapy regimens were compared. Patients (age 1-20 years) with neuroblastoma were eligible to be randomly assigned if they had completed a multidrug induction regimen (cisplatin, carboplatin, cyclophosphamide, vincristine, and etoposide with or without topotecan, vincristine, and doxorubicin) and achieved an adequate disease response. Patients were randomly assigned (1:1) to busulfan and melphalan or to carboplatin, etoposide, and melphalan by minimisation, balancing age at diagnosis, stage, MYCN amplification, and national cooperative clinical group between groups. The busulfan and melphalan regimen comprised oral busulfan (150 mg/m2 given on 4 days consecutively in four equal doses); after Nov 8, 2007, intravenous busulfan was given (0·8-1·2 mg/kg per dose for 16 doses according to patient weight). After 24 h, an intravenous melphalan dose (140 mg/m2) was given. Doses of busulfan and melphalan were modified according to bodyweight. The carboplatin, etoposide, and melphalan regimen consisted of carboplatin continuous infusion of area under the plasma concentration-time curve 4·1 mg/mL per min per day for 4 days, etoposide continuous infusion of 338 mg/m2 per day for 4 days, and melphalan 70 mg/m2 per day for 3 days, with doses for all three drugs modified according to bodyweight and glomerular filtration rate. Stem-cell rescue was given after the last dose of high-dose chemotherapy, at least 24 h after melphalan in patients who received busulfan and melphalan and at least 72 h after carboplatin etoposide, and melphalan. All patients received subsequent local radiotherapy to the primary tumour site followed by maintenance therapy. The primary endpoint was 3-year event-free survival, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01704716, and EudraCT, number 2006-001489-17. FINDINGS: Between June 24, 2002, and Oct 8, 2010, 1347 patients were enrolled and 676 were eligible for random allocation, 598 (88%) of whom were randomly assigned: 296 to busulfan and melphalan and 302 to carboplatin, etoposide, and melphalan. Median follow-up was 7·2 years (IQR 5·3-9·2). At 3 years, 146 of 296 patients in the busulfan and melphalan group and 188 of 302 in the carboplatin, etoposide, and melphalan group had an event; 3-year event-free survival was 50% (95% CI 45-56) versus 38% (32-43; p=0·0005). Nine patients in the busulfan and melphalan group and 11 in the carboplatin, etoposide, and melphalan group had died without relapse by 5 years. Severe life-threatening toxicities occurred in 13 (4%) patients who received busulfan and melphalan and 29 (10%) who received carboplatin, etoposide, and melphalan. The most frequent grade 3-4 adverse events were general condition (74 [26%] of 281 in the busulfan and melphalan group vs 103 [38%] of 270 in the carboplatin, etoposide, and melphalan group), infection (55 [19%] of 283 vs 74 [27%] of 271), and stomatitis (138 [49%] of 284 vs 162 [59%] of 273); 60 (22%) of 267 patients in the busulfan and melphalan group had Bearman grades 1-3 veno-occlusive disease versus 21 (9%) of 239 in the carboplatin, etoposide, and melphalan group. INTERPRETATION: Busulfan and melphalan improved event-free survival in children with high-risk neuroblastoma with an adequate response to induction treatment and caused fewer severe adverse events than did carboplatin, etoposide, and melphalan. Busulfan and melphalan should thus be considered standard high-dose chemotherapy and ongoing randomised studies will continue to aim to optimise treatment for high-risk neuroblastoma. FUNDING: European Commission 5th Framework Grant and the St Anna Kinderkrebsforschung.

Use of Sodium Thiosulfate as an Otoprotectant in Patients With Cancer Treated With Platinum Compounds: A Review of the Literature.

PURPOSE: Hearing loss occurs in 50%-70% of children treated with cisplatin. Scientific efforts have led to the recent approval of a pediatric formula of intravenous sodium thiosulfate (STS) for otoprotection by the US Food and Drug Administration, the European Medicines Agency, and the Medicines and Health Regulatory Authority in the United Kingdom. To inform stakeholders regarding the clinical utility of STS, the current review summarizes available literature on the efficacy, pharmacokinetics (PK), and safety of systemic STS to minimize cisplatin-induced hearing loss (CIHL). DESIGN: A comprehensive narrative review is presented. RESULTS: Thirty-one articles were summarized. Overall, systemic STS effectively reduces CIHL in the preclinical and controlled clinical study settings, in both adults and children with cancer. The extent of CIHL reduction depends on the timing and dosing of STS in relation to cisplatin. Both preclinical and clinical data suggest that systemic STS may affect plasma platinum levels, but studies are inconclusive. Delayed systemic administration of STS, at 6 hours after the cisplatin infusion, does not affect cisplatin-induced inhibition of tumor growth or cellular cytotoxicity in the preclinical setting, nor affect cisplatin efficacy and survival in children with localized disease in the clinical setting. CONCLUSION: Systemic administration of STS effectively reduces the development and degree of CIHL in both the preclinical and clinical settings. More studies are needed on the PK of STS and cisplatin drug combinations, the efficacy and safety of STS in patients with disseminated disease, and the ability of STS to prevent further deterioration of pre-established hearing loss.

The Prognostic Effect of CDKN2A/2B Gene Deletions in Pediatric Acute Lymphoblastic Leukemia (ALL): Independent Prognostic Significance in BFM-Based Protocols.

One of the most frequent genes affected in pediatric ALL is the CDKN2A/2B gene, acting as a secondary cooperating event and playing an important role in cell-cycle regulation and chemosensitivity. Despite its inclusion in combined CNA (copy-number alterations) classifiers, like the IKZF1plus entity and the UKALL CNA profile, the prognostic impact of the individual gene deletions outside the context of a combined CNA evaluation remains controversial. Addressing the CDKN2A/2B deletions' additive prognostic effect in current risk-stratification algorithms, we present a retrospective study of a Greek pediatric ALL cohort comprising 247 patients studied over a 24-year period (2000-2023). Herein, we provide insight regarding the correlation with disease features, MRD clearance, and independent prognostic significance for this ALL cohort treated with contemporary BFM-based treatment protocols. Within an extended follow-up time of 135 months, the presence of the CDKN2A/2B deletions (biallelic or monoallelic) was associated with inferior EFS rates (65.1% compared to 91.8% for the gene non-deleted subgroup, p < 0.001), with the relapse rate accounting for 22.2% and 5.9%, respectively (p < 0.001). The presence of the biallelic deletion was associated with the worst outcomes (EFS 57.2% vs. 89.6% in the case of any other status, monoallelic or non-deleted, p < 0.001). Survival differences were demonstrated for B-ALL cases (EFS 65.3% vs. 93.6% for the non-deleted B-ALL subgroup, p < 0.001), but the prognostic effect was not statistically significant within the T-ALL cohort (EFS 64.3 vs. 69.2, p = 0.947). The presence of the CDKN2A/2B deletions clearly correlated with inferior outcomes within all protocol-defined risk groups (standard risk (SR): EFS 66.7% vs. 100%, p < 0.001, intermediate risk (IR): EFS 77.1% vs. 97.9%, p < 0.001, high risk (HR): EFS 42.1% vs. 70.5% p < 0.001 for deleted vs non-deleted cases in each patient risk group); additionally, in this study, the presence of the deletion differentiated prognosis within both MRD-positive and -negative subgroups on days 15 and 33 of induction. In multivariate analysis, the presence of the CDKN2A/2B deletions was the most important prognostic factor for relapse and overall survival, yielding a hazard ratio of 5.2 (95% confidence interval: 2.59-10.41, p < 0.001) and 5.96 (95% confidence interval: 2.97-11.95, p < 0.001), respectively, designating the alteration's independent prognostic significance in the context of modern risk stratification. The results of our study demonstrate that the presence of the CDKN2A/2B deletions can further stratify all existing risk groups, identifying patient subgroups with different outcomes. The above biallelic deletions could be incorporated into future risk-stratification algorithms, refining MRD-based stratification. In the era of targeted therapies, future prospective controlled clinical trials will further explore the possible use of cyclin-dependent kinase inhibitors (CDKIs) in CDKN2A/2B-affected ALL pediatric subgroups.

Survival patterns of childhood neuroblastoma: an analysis of clinical data from Southern-Eastern European countries.

The prognosis of children with neuroblastoma (NBL) can be dismal with significant variations depending on the stage and biology of the tumor. We assessed the event-free (EFS) and overall (OS) survival using harmonized data from three Southern-Eastern European (SEE) countries. Data for 520 incident NBL cases (2009-2018) were collected from Greece, Slovenia and Russia. Kaplan-Meier curves were fitted, and EFS/OS were derived from Cox proportional models by study variables including the protocol-based risk-group (low/observation, intermediate, high). Over one-third of cases were coded in the high-risk group, of which 23 children (4.4%) received treatment with anti-ganglioside 2 (GD2) mAb. Survival rates were inferior in older (OS 5-year; 1.5-4.9 years: 61%; EFS 5-year; 1.5-4.9 years: 48%) compared to children younger than 1.5 years (OS 5-year; <1.5 years: 91%; EFS 5-year; <1.5 years: 78%). Predictors of poor OS included stage 4 (hazard ratio, HR OS : 18.12, 95% confidence intervals, CI: 3.47-94.54), N-myc amplification (HR OS : 2.16, 95% CI: 1.40-3.34), no surgical excision (HR OS : 3.27, 95% CI: 1.91-5.61) and relapse/progression (HR OS : 5.46, 95% CI: 3.23-9.24). Similar unfavorable EFS was found for the same subsets of patients. By contrast, treatment with anti-GD2 antibody in high-risk patients was associated with decreased risk of death or unfavorable events (HR OS : 0.11, 95% CI: 0.02-0.79; HR EFS : 0.19, 95% CI: 0.07-0.52). Our results confirm the outstanding prognosis of the early NBL stages, especially in children <1.5 years, and the improved outcomes of the anti-GD2 treatment in high-risk patients. Ongoing high-quality clinical cancer registration is needed to ensure comparability of survival across Europe and refine our understanding of the NBL biology.

A rare case of neonatal systemic xanthogranulomatosis with severe hepatic disease and metachronous skin involvement.

Juvenile xanthogranuloma (JXG) is a rare benign disorder of unknown pathogenesis, usually a self-limited condition. Extracutaneous systematic involvement is infrequent. We report one of the few documented cases of congenital systemic JXG, presenting with fever, jaundice, hepatosplenomegaly, ascites, pancytopenia, and delayed skin involvement. Liver biopsy established the diagnosis and JXG was not demonstrated in the bone marrow. Rapid deterioration of liver disease and pancytopenia, prompted us to administer immunosuppressive treatment (Langerhans cell histiocytosis-II Protocol). The patient's clinical condition improved and visceral and skin lesions showed gradual involution. The patient is still free of disease 4 years after the initial presentation.

Chronic myeloid leukemia (CML) in children: classical and newer therapeutic approaches.

Chronic myeloid leukemia (CML) represents a rare myeloproliferative disease among children where allogeneic stem cell transplantation (SCT) remains the curative gold standard. However, the impressive early cytogenetic and molecular responses achieved by tyrosine kinase inhibitors [TKIs (imatinib, nilotinib, and dasatinib)] as first-line or even sole treatment in adults, has led to their increasing use also among children. Due to limited data regarding long-term results of TKIs and especially those of second generation in pediatric cohorts, we would like to add clinical information in this rare series of patients by reporting on four children with CML over a 10-year period, focusing on TKIs, dose escalations and clinical responses.

Clinical Phenotype and Management of Severe Neurotoxicity Observed in Patients with Neuroblastoma Treated with Dinutuximab Beta in Clinical Trials.

Neurotoxicity is an off-tumour, on-target side effect of GD2-directed immunotherapy with monoclonal antibodies. Here, we report the frequency, management and outcome of patients enrolled in two prospective clinical trials who experienced severe neurotoxicity during immunotherapy with the anti-GD2 antibody dinutuximab beta (DB) administered as short-term infusion (HR-NBL1/SIOPEN study, randomisation R2, EudraCT 2006-001489-17) or as long-term infusion (HR-NBL1/SIOPEN study, randomisation R4, EudraCT 2006-001489-17 and LTI/SIOPEN study, EudraCT 2009-018077-31), either alone or with subcutaneous interleukin-2 (scIL-2). The total number of patients included in this analysis was 1102. Overall, 44/1102 patients (4.0%) experienced Grade 3/4 neurotoxicities (HR-NBL1 R2, 21/406; HR-NBL1 R4, 8/408; LTI study, 15/288), including 27 patients with severe neurotoxicities (2.5%). Events occurred predominantly in patients receiving combined treatment with DB and scIL-2. Neurotoxicity was treated using dexamethasone, prednisolone, intravenous immunoglobulins and, in two patients, plasmapheresis, which was highly effective. While neurological recovery was observed in 16 of 21 patients with severe neurotoxicities, 5/1102 (0.45%) patients experienced persistent and severe neurological deficits. In conclusion, severe neurotoxicity is most commonly observed in patients receiving DB with scIL-2. Considering the lack of clinical benefit for IL-2 in clinical trials so far, the administration of IL-2 alongside DB is not recommended.

Neuroblastoma survivors at risk for developing subsequent neoplasms: A systematic review.

Neuroblastoma survivors have an increased risk of unfavorable long-term health outcomes, of which developing subsequent neoplasms is one of the most serious. We aimed to provide an overview of the current knowledge on the risk of subsequent neoplasms in neuroblastoma survivors. We conducted a systematic literature search in Medline/Pubmed (01-01-1945-13-01-2022) to identify studies that reported on ≥ 100 neuroblastoma survivors and assessed subsequent neoplasms as an outcome. We identified 410 potentially eligible articles, of which we eventually included 13 reports. All articles described retrospective cohorts with sizes varying from 145 to 5,987 neuroblastoma survivors. Within these cohorts 0.7% - 17.2% of the survivors developed a subsequent neoplasm. A wide variety of types of subsequent malignant and non-malignant neoplasms were observed, of which thyroid carcinoma and acute myeloid leukemia were most frequently reported. The risk of developing a subsequent neoplasm was 2.8 to 10.4 times higher in neuroblastoma survivors than in the general population. Although no statistically significant risk factors for subsequent neoplasms were observed in multivariable analyses, high-risk group survivors, women and those treated with radiotherapy seemed to have a higher risk. In conclusion, the studies in this systematic review consistently show that neuroblastoma survivors are at elevated risk of developing subsequent neoplasms. Future research should further explore risk factors for subsequent neoplasms in neuroblastoma survivors, so future treatment protocols and follow-up care can be improved.

Suprarenal Masses in Very Young Infants: Is It Safe to Watch and Wait? Report of a SIOPEN Observational Study Results.

Background: To assess whether expectant observation of infants ≤ 90 days old with small suprarenal masses (sSRMs) could avoid unnecessary surgery without impacting outcome. Methods: Infants ≤ 90 days with a ≤ 5 cm mass, without midline extension or lymph node or distant spread were registered (ClinicalTrials.org:NCT01728155). Once staging was completed, they were followed with ultrasound, MRI and urinary catecholamines. Surgical resection was only planned if there was a ≥40% mass volume increase or for a mass persisting after 48 weeks of the planned observation. Results: Over a 5-year period, 128 infants were registered. No infant had detectable MYCN amplification in the peripheral blood. Surgery was performed in 39 (30.5%) patients, in 18 during and in 21 after the planned 48-week observation, and 74% were confirmed to be neuroblastomas. Non-life-threatening surgical complications occurred in two cases. The 3-year overall survival and event-free survival were 100% and 87.1%, respectively. The 16 events observed were volume increase (N = 11) and progression to neuroblastoma stage MS (N = 5). Patients with solid masses or MIBG-positive masses had lower EFS. Conclusions: Expectant observation for infants with sSRMs with clinical follow-up and timely imaging (including MRI scan) is safe and effective, allowing surgery to be avoided in the majority of them.