Daniel A. Morgenstern

Current and Future Strategies for Relapsed Neuroblastoma: Challenges on the Road to Precision Therapy

More than half of the patients with high-risk neuroblastoma (NB) will relapse despite intensive multimodal therapy, with an additional 10% to 20% refractory to induction chemotherapy. Management of these patients is challenging, given disease heterogeneity, resistance, and organ toxicity including poor hematological reserve. This review will discuss the current treatment options and consider novel therapies on the horizon. Cytotoxic chemotherapy regimens for relapse and refractory NB typically center on the use of the camptothecins, topotecan and irinotecan, in combination with agents such as cyclophosphamide and temozolomide, with objective responses but poor long-term survival. 131I-meta-iodobenzylguanidine therapy is also effective for relapsed patients with meta-iodobenzylguanidine-avid disease, with objective responses in a third of cases. Immunotherapy with anti-GD2 has recently been incorporated into upfront therapy, but its role in the relapse setting remains uncertain, especially for patients with bulky disease. Future cell-based immunotherapies and other approaches may be able to overcome this limitation. Finally, many novel molecularly targeted agents are in development, some of which show specific promise for NB. Successful incorporation of these agents will require combinations with conventional cytotoxic chemotherapies, as well as the development of predictive biomarkers, to ultimately personalize approaches to patients with “targetable” molecular abnormalities.

Toxicity and Outcome of Children and Adolescents Participating in Phase I/II Trials of Novel Anticancer Drugs: The Royal Marsden Experience

Early phase trials are crucial in developing new therapies for poor prognosis childhood malignancies. Outcomes and toxicities of children treated on phase I/II trials at the Royal Marsden, one of the largest pediatric oncology early phase trial units in Europe, were examined to provide a baseline dataset and generate hypotheses. All patients recruited over a 10-year period to December 2011 were included. Variables including baseline characteristics, time on study, survival, toxicities, and admissions were collected. Seventy-two patients were recruited to 21 trials (5 phase I, 16 phase II; overall 12 involved molecularly targeted agents). Median age at consent was 12.4 years. Dose-limiting toxicities were rare in phase I trial participants (2 of 15 evaluable patients, 13%); the most common reason for leaving trials was disease progression (76%), rather than drug toxicity (1.7%). Median time on trial was 1.3 months (phase I patients) and 3.3 months (phase II). Early phase trials in children are safe and unexpected toxic side effects are infrequent. Patients and their families are willing to travel to access novel therapies, although the overall prognosis for these individuals is poor. Continued expansion of the portfolio is needed ultimately to improve the outcomes for those with resistant disease.

Phase I Study of Vinblastine and Sirolimus in Pediatric Patients With Recurrent or Refractory Solid Tumors

The combination of vinblastine and mammalian target of rapamycin (mTOR) inhibitor sirolimus inhibits the growth of neuroblastoma xenografts through pro‐apoptotic and anti‐angiogenic mechanisms. This phase I study aimed to explore the safety and toxicity of this combination in pediatric patients with advanced solid tumors.

Metastatic Neuroblastoma Confined to Distant Lymph Nodes (stage 4N) Predicts Outcome in Patients With Stage 4 Disease: A Study From the International Neuroblastoma Risk Group Database

PURPOSEnThe presence of distant metastases is one of the most powerful predictors of outcome in patients with neuroblastoma. However, the pattern of metastatic spread is not incorporated into current risk stratification systems. Small case series have suggested that patients with neuroblastoma who have metastatic disease limited to distant lymph nodes (4N disease) may have improved outcomes.nnnPATIENTS AND METHODSnWe analyzed retrospective data from the International Neuroblastoma Risk Group database for patients diagnosed from 1990 to 2002. 4N patients were compared with the remaining stage 4 patients (non-4N), excluding those with missing metastatic site data.nnnRESULTSnIn all, 2,250 International Neuroblastoma Staging System stage 4 patients with complete data were identified, of whom 146 (6.5%) had 4N disease. For 4N patients, event-free survival (EFS; 5-year, 77% ± 4%) and overall survival (OS; 5-year, 85% ± 3%) were significantly better than EFS (5-year, 35% ± 1%) and OS (5-year, 42% ± 1%) for non-4N stage 4 patients (P < .001). 4N patients were more likely to be younger (P < .001) and have tumors with favorable characteristics, including absence of MYCN amplification (89% v 69%; P < .001). In a multivariable analysis, 4N disease remained a significant predictor of outcome (hazard ratio for non-4N v 4N: 3.40 for EFS and 3.69 for OS). Within subgroups defined by age at diagnosis and tumor MYCN status, 4N disease was significantly associated with improved outcomes.nnnCONCLUSIONn4N represents a subgroup with better outcome than that of other patients with metastatic disease. These findings suggest that the biology and treatment response of 4N tumors differ from other stage 4 tumors, and less intensive therapy should be considered for this cohort. Future exploration of biologic factors determining the pattern of metastatic spread is warranted.

Prognostic significance of pattern and burden of metastatic disease in patients with stage 4 neuroblastoma: A study from the International Neuroblastoma Risk Group database

Neuroblastoma is a childhood cancer with remarkably divergent tumour behaviour and the presence of metastatic disease is a powerful predictor of adverse outcome. However, the importance of the involvement of specific metastatic sites or overall metastatic burden in determining outcome has not been fully explored. We analysed data from the International Neuroblastoma Risk Group database for 2250 patients with stage 4 disease treated from 1990 to 2002. Metastatic burden was assessed using a metastatic site index (MSI), a score based on the number of metastatic systems involved. Overall, involvement of bone marrow, bone, lung, central nervous system, or other sites was associated with worse outcome. For patients aged ≥18 months, involvement of liver had the greatest impact on outcome and was associated with tumour MYCN amplification and adrenal primary and lung metastases. Increased MSI was associated with worse outcome and higher baseline ferritin/lactate dehydrogenase. We explored the impact of initial treatment approach on these associations. Limiting the analysis to patients allocated to protocols including stem cell transplant (SCT), there was no longer an association of outcome with metastatic involvement of any individual system or increasing MSI. Thus, treatment escalation with SCT (and the addition of differentiating agents to maintenance therapy) appears to have provided maximal benefit to patients with greatest metastatic disease burden. These findings underscore the importance of examining prognostic factors in the context of specific treatments since the addition of new therapies may change or even negate the predictive impact of a particular variable.

Adaptive dosing of anticancer drugs in neonates: facilitating evidence-based dosing regimens

PurposeSelection of the most appropriate chemotherapy dosing regimens for neonates treated within the first weeks of life represents a significant clinical dilemma. Due to a lack of information relating to the clinical pharmacology of anticancer drugs in these challenging patients, current dosing guidelines are based on limited scientific rationale. In the current study, we investigate the utilisation of therapeutic drug monitoring approaches in neonates with localised hepatoblastoma, Wilms’ tumour and stage 4S neuroblastoma, being treated with widely used anticancer drugs.MethodsPlasma concentrations of cisplatin, vincristine, etoposide and carboplatin were quantified in two neonates being treated within the first 3xa0weeks of life and in a 32-week preterm infant treated at a gestational age of 40xa0weeks. Therapeutic drug monitoring was carried out where appropriate, based on the pharmacokinetic data obtained in conjunction with clinical response and toxicity.ResultsTreatment of a child aged 2xa0weeks with a recommended cisplatin dose reduction for weight to 1.8xa0mg/kg resulted in achievement of unbound cisplatin plasma concentrations of 0.01–0.08xa0µg/mL, markedly lower than exposures previously reported in infants and older children. A dose increase to 2.7xa0mg/kg was implemented, leading to the achievement of levels more in-line with those previously reported. This increased dose level was well tolerated over six courses of treatment, resulting in a good response to cisplatin monotherapy and the patient remains in remission at 3.5xa0years. In contrast, a 50xa0% vincristine dose reduction for weight in a 3-week-old neonate resulted in plasma concentrations comparable to levels observed in older children, leading to successful treatment and continued remission at 2xa0years. In a third patient, etoposide and carboplatin clearance values normalised to body weight were comparable to those reported in older children, resulting in comparatively lower exposures following reduced dosing.ConclusionsThe current report provides unique data on the pharmacokinetics of several widely used anticancer drugs in neonates treated within the first few weeks of life. The provision of these data acts as a useful reference point to support future dosing decisions to be made by clinicians in the treatment of these challenging patients.

Post-thaw viability of cryopreserved peripheral blood stem cells (PBSC) does not guarantee functional activity: important implications for quality assurance of stem cell transplant programmes

Standard quality assurance (QA) of cryopreserved peripheral blood stem cells (PBSC) uses post‐thaw viable CD34+ cell counts. In 2013, concerns arose at Great Ormond Street Hospital (GOSH) about 8 patients with delayed engraftment following myeloablative chemotherapy with cryopreserved cell rescue, despite adequate post‐thaw viable cell counts in all cases. Root cause analysis was undertaken; investigations suggested the freeze process itself was a contributing factor to suboptimal engraftment. Experiments were undertaken in which a single PBSC product was divided into three and cryopreserved in parallel using a control‐rate freezer (CRF) or passive freezing method (−80°C freezer) at GOSH, or the same passive freezing at another laboratory. Viable CD34+ counts were equivalent and adequate in each. Granulocyte‐monocyte colony‐forming unit assays demonstrated colonies from the products cryopreserved using passive freezing (both laboratories), but no colonies from products cryopreserved using the CRF. The CRF was shown to be operating within manufacturers specifications with freeze‐profile within acceptable limits. This experience has important implications for quality assurance for all transplant programmes, particularly those using cryopreserved products. The failure of post‐thaw viable CD34+ counts, the most widely used routine QA test available, to ensure PBSC function is of great concern and should prompt reassessment of protocols and QA procedures.

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

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.

Accelerating drug development in pediatric cancer: a novel Phase I study design of venetoclax in relapsed/refractory malignancies

Venetoclax is a highly selective, potent BCL-2 inhibitor that is approved for some patients previously treated for chronic lymphocytic leukemia, and has shown promising activity in adult studies across several hematologic malignancies. Preclinical studies have demonstrated venetoclax activity in pediatric patient-derived xenograft models and cell lines; however, clinical studies in pediatric patients have yet to be conducted. The prognosis is poor for children with most relapsed/refractory malignancies, and limited treatment options result in unmet clinical need. Herein, we describe the rationale and design of the first study of venetoclax in pediatric patients with relapsed/refractory malignancies: a Phase I trial investigating the safety and pharmacokinetics of venetoclax monotherapy followed by the addition of chemotherapy (Trial registration: EudraCT 2017-000439-14; NCT03236857).

Persisting inequalities in survival patterns of childhood neuroblastoma in Southern and Eastern Europe and the effect of socio-economic development compared with those of the US

AIMnNeuroblastoma outcomes vary with disease characteristics, healthcare delivery and socio-economic indicators. We assessed survival patterns and prognostic factors for patients with neuroblastoma in 11 Southern and Eastern European (SEE) countries versusxa0those in the US, including-for the first time-the Nationwide Registry for Childhood Hematological Malignancies and Solid Tumours (NARECHEM-ST)/Greece.nnnMETHODSnOverall survival (OS) was calculated in 13 collaborating SEE childhood cancer registries (1829 cases, ∼1990-2016) and Surveillance, Epidemiology, and End Results (SEER), US (3072 cases, 1990-2012); Kaplan-Meier curves were used along with multivariable Cox regression models assessing the effect of age, gender, primary tumour site, histology, Human Development Index (HDI) and place of residence (urban/rural) on survival.nnnRESULTSnThe 5-year OS rates varied widely among the SEE countries (Ukraine: 45%, Poland: 81%) with the overall SEE rate (59%) being significantly lower than in SEER (77%; pxa0<xa00.001). In the common registration period within SEE (2000-2008), no temporal trend was noted as opposed to a significant increase in SEER. Age >12 months (hazard ratio [HR]: 2.8-4.7 in subsequent age groups), male gender (HR: 1.1), residence in rural areas (HR: 1.3), living in high (HR: 2.2) or medium (HR: 2.4) HDI countries and specific primary tumour location were associated with worse outcome; conversely, ganglioneuroblastoma subtype (HR: 0.28)xa0was associated with higher survival rate.nnnCONCLUSIONSnAllowing for the disease profile, children with neuroblastoma in SEE, especially those in rural areas and lower HDI countries, fare worse than patients in the US, mainly during the early years after diagnosis; this may be attributed to presumably modifiable socio-economic and healthcare system performance differentials warranting further research.