Targeted Immunotherapy for High-Risk Neuroblastoma—The Role of Monoclonal Antibodies

Mechanisms, Characteristics, and Treatment of Neuropathic Pain and Peripheral Neuropathy Associated with Dinutuximab in Neuroblastoma Patients

Prognosis of metastatic neuroblastoma is very poor. Its treatment includes induction chemotherapy, surgery, high-dose chemotherapy, radiotherapy, and maintenance with retinoic acid, associated with the anti-GD2 monoclonal antibody (ch14.18) dinutuximab. Immunotherapy determined a significant improvement in survival rate and is also utilized in relapsed and resistant neuroblastoma patients. Five courses of dinutuximab 100 mg/m² are usually administered as a 10-day continuous infusion or over 5 consecutive days every 5 weeks. Dinutuximab targets the disialoganglioside GD2, which is highly expressed on neuroblastoma cells and minimally present on the surface of normal human neurons, peripheral pain fibers, and skin melanocytes. Anti GD2 antibodies bind to surface GD2 and determine the lysis of neuroblastoma cells induced by immune response via the antibody-dependent cellular cytotoxicity and the complement-dependent cytotoxicity. Dinutuximab has significant side effects, including neuropathic pain, peripheral neuropathy, hypersensitivity reactions, capillary leak syndrome, photophobia, and hypotension. The most important side effect is neuropathic pain, which is triggered by the same antibody–antigen immune response, but generates ectopic activity in axons, which results in hyperalgesia and spontaneous pain. Pain can be severe especially in the first courses of dinutuximab infusion, and requires the administration of gabapentin and continuous morphine infusion. This paper will focus on the incidence, mechanisms, characteristics, and treatment of neuropathic pain and peripheral neuropathy due to dinutuximab administration in neuroblastoma patients.

Mechanisms of Therapeutic Antitumor Monoclonal Antibodies

Monoclonal antibodies (mAb) are a major component of cancer therapy. In this review, we summarize the different therapeutic mAbs that have been successfully developed against various tumor-expressed antigens and examine our current understanding of their different mechanisms of antitumor action. These mechanisms of action (MOA) largely center on the stimulation of different innate immune effector processes, which appear to be principally responsible for the efficacy of most unconjugated mAb therapies against cancer. This is evident in studies of mAbs targeting antigens for hematologic cancers, with emerging data also demonstrating the critical nature of innate immune-mediated mechanisms in the efficacy of anti-HER2 mAbs against solid HER2+ cancers. Although HER2-targeted mAbs were originally described as inhibitors of HER2-mediated signaling, multiple studies have since demonstrated these mAbs function largely through their engagement with Fc receptors to activate innate immune effector functions as well as complement activity. Next-generation mAbs are capitalizing on these MOAs through improvements to enhance Fc-activity, although regulation of these mechanisms may vary in different tumor microenvironments. In addition, novel antibody-drug conjugates have emerged as an important means to activate different MOAs. Although many unknowns remain, an improved understanding of these immunologic MOAs will be essential for the future of mAb therapy and cancer immunotherapy.

Tolerance of dinutuximab therapy for treatment of high-risk neuroblastoma in two patients with end-stage renal disease on dialysis

Autologous hematopoietic cell transplant (aHCT) has a significant survival advantage in patients with high-risk (HR) neuroblastoma. Transplant-associated thrombotic microangiopathy (TA-TMA) is a serious complication and may result in chronic renal disease leading to delay in subsequent posttransplant therapy and limitations of treatment options. Dinutuximab represents an important therapeutic advance in the treatment of pediatric HR neuroblastoma, but historically has not been administered in patients with GFR < 60 mL/m² /min. Here, we present the safe outcome of dinutuximab administration while on renal replacement therapy in two cases of HR neuroblastoma with end-stage renal disease secondary to TA-TMA.

Frequency of ALK and GD2 Expression in Neuroblastoma

Background: The aim of this study was to elucidate the significance of immunohistochemical staining patterns of ALK and GD2 in peripheral neuroblastic tumors with different stages and favorable/unfavorable features. Materials and methods: 32 neuroblastomas, 7 ganglioneuroblastomas, and 1 ganglioneuroma cases were immunohistochemically stained with ALK and GD2, and the expressions were graded and correlated with differentiation, size, and favorable/unfavorable histology. Results: There was no statistically significant correlation between ALK immunopositivity and tumor differentiation or stage. Although there was no statistically significant correlation between GD2 immunopositivity and stage, the intensity and prevalence of GD2 immunostaining were statistically significantly higher in the well differentiated group and in tumors which were smaller than 10 cm. Conclusion: GD2 immunostaining levels correlated with tumor differentiation and size. ALK immunostaining was not related to tumor differentiation or stage.

The safety of dinutuximab for the treatment of pediatric patients with high-risk neuroblastoma

INTRODUCTION

Dinutuximab, an anti-GD2 antibody, specifically targets the high-expression of GD2 on neuroblastoma cells, and its incorporation into maintenance high-risk neuroblastoma therapy has increased event-free survival for this devastating disease. Efficacy of dinutuximab during other phases of therapy or in relapsed and refractory patients remains under investigation. Areas covered: This review looked at available publications (via PubMed search and online abstract catalogs of recent scientific meetings) on pre-clinical safety studies of dinutuximab as well as results and current impressions of pending trials including dinutuximab and other anti-GD2 antibodies. While dinutuximab has become the standard of care for maintenance therapy in many cooperative trials, long-term follow-ups as well as ongoing assessment about timing of antibody use and co-administration of other pharmacologic or immune-modulatory agents remains under study. Expert opinion: Results of these and ongoing trials demonstrate prolonged time to first relapse and potentially overall survival benefit when dinutuximab is used during maintenance therapy. The role cytokines administered in conjunction with dinutuximab remains unclear and may increase toxicity without additional benefit. Current also investigations demonstrate promising efficacy in relapsed and refractory neuroblastoma. Further study is warranted in order to appropriately incorporate dinutuximab into current treatment strategies.

Expression of Disialoganglioside (GD2) in Neuroblastic Tumors: A Prognostic Value for Patients Treated With Anti-GD2 Immunotherapy

Neuroblastoma, a malignant neoplasm of the sympathetic nervous system, is one of the most aggressive pediatric cancers. Patients with stage IV high-risk neuroblastoma receive an intensive multimodal therapy ending with an immunotherapy based on a chimeric monoclonal antibody ch14.18. Although the use of ch14.18 monoclonal antibody has significantly increased the survival rate of high-risk neuroblastoma patients, about 33% of these patients still relapse and die from their disease. Ch14.18 targets the disialoganglioside, GD2, expressed on neuroblastic tumor (NT) cells. To better understand the causes of tumor relapse following ch14.18 immunotherapy, we have analyzed the expression of GD2 in 152 tumor samples from patients with NTs using immunohistochemical stainings. We observed GD2 expression in 146 of 152 samples (96%); however, the proportion of GD2-positive cells varied among samples. Interestingly, low percentage of GD2-positive cells before immunotherapy was associated with relapse in patients receiving ch14.18 immunotherapy. In addition, we demonstrated in vitro that the sensitivity of neuroblastoma cell lines to natural killer-mediated lysis was dependent on the proportion of GD2-positive cells, in the presence of ch14.18 antibody. In conclusion, our results indicate that the proportion of tumor cells expressing GD2 in NTs should be taken in consideration, as a prognostic marker, for high-risk neuroblastoma patients receiving anti-GD2 immunotherapy.

High Serum Level of Soluble Programmed Death Ligand 1 is Associated With a Poor Prognosis in Hodgkin Lymphoma

Blockade of the programmed cell death 1-programmed cell death ligand 1 pathway is a new and promising therapeutic approach in Hodgkin lymphoma (HL). To our knowledge, the impact of soluble programmed cell death ligand 1 (sPD-L1) serum levels on HL patient prognosis has not yet been investigated. In this study, the prognostic value of sPD-L1 was assessed in patients with HL. We measured serum sPD-L1 levels and identified their prognostic value in 108 newly diagnosed HL patients using an enzyme-linked immunosorbent assay (ELISA). We found higher serum sPD-L1 concentrations in HL patients than in healthy controls. The best sPD-L1 cutoff value for predicting disease progression risk was 25.1674 ng/ml. The 4-year progression-free survival (PFS) rates for the high-sPD-L1 and low-sPD-L1 groups were 78.8% and 93.3%, respectively. Multivariate survival analysis showed that advanced stage and higher sPD-L1 levels (>25.1674 ng/ml) were independent prognostic factors for shorter PFS. In addition, higher sPD-L1 levels were positively correlated with advanced stage and negatively correlated with peripheral blood monocyte number. The serum sPD-L1 level is an independent prognostic factor for PFS in HL patients and may allow identification of a subgroup of patients who require more intensive therapy and who may benefit from anti-PD-1 agents.

Transverse myelitis as an unexpected complication following treatment with dinutuximab in pediatric patients with high-risk neuroblastoma: A case series

Immunotherapy with the anti-GD2 monoclonal antibody ch14.18, or dinutuximab, represents an important therapeutic advance in the treatment of pediatric high-risk neuroblastoma and is now considered part of standard of care in this patient population. To date, transverse myelitis as a result of dinutuximab therapy has not been reported in clinical trials or in the published literature. We describe three patients with clinical symptoms of transverse myelitis, confirmed via magnetic resonance imaging, shortly following initiation of dinutuximab. All patients were discontinued from dinutuximab treatment and received urgent treatment, with rapid improvement in symptoms and resultant functional recovery.

New Strategies Using Antibody Combinations to Increase Cancer Treatment Effectiveness

Antibodies have proven their high value in antitumor therapy over the last two decades. They are currently being used as the first-choice to treat some of the most frequent metastatic cancers, like HER2⁺ breast cancers or colorectal cancers, currently treated with trastuzumab (Herceptin) and bevacizumab (Avastin), respectively. The impressive therapeutic success of antibodies inhibiting immune checkpoints has extended the use of therapeutic antibodies to previously unanticipated tumor types. These anti-immune checkpoint antibodies allowed the cure of patients devoid of other therapeutic options, through the recovery of the patient’s own immune response against the tumor. In this review, we describe how the antibody-based therapies will evolve, including the use of antibodies in combinations, their main characteristics, advantages, and how they could contribute to significantly increase the chances of success in cancer therapy. Indeed, novel combinations will consist of mixtures of antibodies against either different epitopes of the same molecule or different targets on the same tumor cell; bispecific or multispecific antibodies able of simultaneously binding tumor cells, immune cells or extracellular molecules; immunomodulatory antibodies; antibody-based molecules, including fusion proteins between a ligand or a receptor domain and the IgG Fab or Fc fragments; autologous or heterologous cells; and different formats of vaccines. Through complementary mechanisms of action, these combinations could contribute to elude the current limitations of a single antibody which recognizes only one particular epitope. These combinations may allow the simultaneous attack of the cancer cells by using the help of the own immune cells and exerting wider therapeutic effects, based on a more specific, fast, and robust response, trying to mimic the action of the immune system.

Chemoimmunotherapeutic effect of combined treatment with ex vivo generated antigen-presenting immune cells and conventional antitumor agents in a mouse neuroblastoma model

PURPOSE

Combining antitumor immunotherapy with conventional intensive multimodal therapy may be considered for advanced neuroblastoma. We investigated combination therapy with ex vivo generated immunostimulatory cells and intraperitoneal doxorubicin.

METHODS

Immunogenic death of neuro-2a neuroblastoma cells was induced by doxorubicin or cisplatin (negative control). Mouse bone marrow cells were cultured with granulocyte-macrophage colony-stimulating factor, followed by addition of doxorubicin-killed neuro-2a cells with or without interleukin-4 and/or CpG-oligodeoxynucleotide to induce immunostimulatory cells. CD8α⁺ lymphocytes were cocultured with killed neuro-2a cells and immunostimulatory cells, and interferon-γ was measured in the supernatant. Furthermore, female A/J mice were injected with viable neuro-2a cells, followed by immunostimulatory cells and doxorubicin. Then intraabdominal tumor nodules were evaluated.

RESULTS

Bone marrow-derived immunostimulatory cells only promoted interferon-γ production by CD8α⁺ lymphocytes after first being stimulated by doxorubicin-killed neuro-2a cells and interleukin-4, followed by CpG-oligodeoxynucleotide. These cells had a surface antigen expression profile compatible with activated dendritic cells and suppressed tumors in mice intravenously injected with neuro-2a cells. Despite a similar surface antigen profile, the in vivo antitumor effect was stronger after injection of immunostimulatory cells induced by doxorubicin-killed neuro-2a cells compared with cells induced by cisplatin-killed neuro-2a cells. Moreover, interferon-γ production was greater when CD8α⁺ lymphocytes were cocultured with doxorubicin-killed neuro-2a cells and immunostimulatory cells rather than with cisplatin-killed cells.

CONCLUSION

Cells with antitumor activity can be induced from bone marrow cells. Combining such cells with doxorubicin may activate antitumor immunity in tumor-bearing mice. Interactions between induced immunostimulatory cells and conventional chemotherapy might be important for antitumor immunity.

Dinutuximab: A Review in High-Risk Neuroblastoma

Dinutuximab (ch14.18; Unituxin™) is a chimeric human-mouse monoclonal antibody that binds to the glycolipid antigen disialoganglioside, which is highly expressed on the surface of neuroblastoma cells. This intravenous drug is approved in the EU and USA as combination therapy with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-2 and isotretinoin for the postconsolidation treatment of patients with high-risk neuroblastoma. In a multinational, phase III study in this patient population, event-free survival (EFS) benefits with the dinutuximab-containing regimen versus isotretinoin alone were observed at the time of the primary (p = 0.0115) and confirmatory (p = 0.0330) efficacy analyses, although the observed p-value for the between-group difference in EFS for the primary efficacy analysis did not cross the prespecified boundary for statistical significance (p < 0.0108). Significant and sustained (5 years) overall survival benefits were seen with the dinutuximab-containing regimen versus isotretinoin alone. Despite pretreatment with analgesics, antihistamines and antipyretics, serious adverse reactions have been reported with the dinutuximab-containing regimen, with infusion reactions and neuropathy prompting the US FDA to issue boxed warnings. Dinutuximab administered in combination with GM-CSF, IL-2 and isotretinoin represents an important advance in the postconsolidation treatment of patients with high-risk neuroblastoma, with its benefits outweighing its risks in a patient population with a poor prognosis and limited therapeutic options.

The Role of Nursing Professionals in the Management of Patients With High-Risk Neuroblastoma Receiving Dinutuximab Therapy

Neuroblastoma, an embryonic cancer of the sympathetic nervous system, is the most common extracranial solid tumor in childhood. Dinutuximab (formerly called ch14.18), a monoclonal antibody targeting the disialoganglioside GD2, has been shown to significantly improve survival rates in patients with high-risk neuroblastoma. However, the safe and effective use of dinutuximab therapy in these high-risk patients requires medical expertise in patient selection, treatment administration, and the monitoring and management of adverse events. Findings of the randomized phase III study (ANBL0032) led to the approval of dinutuximab for the treatment of children with high-risk neuroblastoma. Multi-institutional nursing approaches to implementing standard protocols ensure the effective management of high-risk neuroblastoma patients receiving dinutuximab immunotherapy. Understanding and implementing recommendations for the management of the clinically important and most common adverse events are essential to ensuring patient continuation of therapy and improving patient outcomes.

In vivo expansion and activation of γδ T cells as immunotherapy for refractory neuroblastoma: A phase 1 study

INTRODUCTION

CD3+ γδ+ T cells comprise 2% to 5% of circulating T cells with Vγ9Vδ2+ cells the dominant circulating subtype. Vγ9Vδ2+ cells recognize non-peptide phosphoantigens and stress-associated NKG2D ligands expressed on malignant cells. Strategies that incorporate the tumoricidal properties of γδ T cells represent a promising immunotherapeutic strategy for treatment of solid malignancies including neuroblastoma (NB). In this prospective, non-randomized Phase I trial, we assessed whether circulating Vγ9Vδ2+ cells could be safely expanded using intravenous ZOL (Zoledronate [Zometa]) and subcutaneous Interleukin-2 (IL-2) in patients with refractory NB.

METHODS

Patients 2 to 21 years of age with refractory neuroblastoma with no known curative therapeutic options received ZOL on day 1, and IL-2 on days 1 to 5 and 15 to 19 of each 28-day cycle (n = 4). Lymphocyte immunophenotyping was assessed weekly. Immunophenotyping studies from the treatment group were compared with healthy pediatric controls (n = 16; range, 5y-15y) and of untreated NB disease controls (n = 9; range, 4m-18y).

RESULTS

Treatment was well tolerated with no unexpected grade 3 and 4 toxicities. Lymphocyte subset counts did not differ significantly between volunteers and disease controls with the exception of γδ+ T cell counts that were significantly higher in healthy volunteers (212 + 93 vs. 89 + 42, P = 0.05). Study patients showed increases in circulating γδ+ T cell count (3-10 fold) after the first week, increasing into the range seen in healthy volunteers (125 + 37, P = 0.1940). Interestingly, all ZOL + IL-2 treated patients showed significant increases in CD3+CD4+CD27CD127 T cells that rose weekly in 2 patients throughout the 4 weeks of observation (maximum 41% and 24% of total CD3+CD4+ T cells, respectively).

CONCLUSIONS

In summary, combined ZOL and IL-2 is well tolerated and restored γδ+ T cell counts to the normal range with a moderate expansion of Natural Killer cells. Progressive increases in circulating CD4+ T cells with a regulatory phenotype cells may offset beneficial effects of this therapy.

Charge heterogeneity: Basic antibody charge variants with increased binding to Fc receptors

We identified active isoforms of the chimeric anti-GD2 antibody, ch14.18, a recombinant antibody produced in Chinese hamster ovary cells, which is already used in clinical trials.^1,2,3 We separated the antibody by high resolution ion-exchange chromatography with linear pH gradient elution into acidic, main and basic charge variants on a preparative scale yielding enough material for an in-depth study of the sources and the effects of microheterogeneity. The binding affinity of the charge variants toward the antigen and various cell surface receptors was studied by Biacore. Effector functions were evaluated using cellular assays for antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. Basic charge variants showed increased binding to cell surface receptor FcγRIIIa, which plays a major role in regulating effector functions. Furthermore, increased binding of the basic fractions to the neonatal receptor was observed. As this receptor mediates the prolonged half-life of IgG in human serum, this data may well hint at an increased serum half-life of these basic variants compared to their more acidic counterparts. Different glycoform patterns, C-terminal lysine clipping and N-terminal pyroglutamate formation were identified as the main structural sources for the observed isoform pattern. Potential differences in structural stability between individual charge variant fractions by nano differential scanning calorimetry could not been detected. Our in-vitro data suggests that the connection between microheterogeneity and the biological activity of recombinant antibody therapeutics deserves more attention than commonly accepted.

Dinutuximab

Therapy combining dinutuximab with granulocyte macrophage colony stimulating factor, interleukin 2, and isotretinoin has significant side effects; however, these complications are generally predictable and can be managed proactively.

Dinutuximab: first global approval

United Therapeutics Corporation and the National Cancer Institute are developing dinutuximab (Unituxin™; ch14.18), a monoclonal antibody targeting GD2, for the treatment of neuroblastoma. GD2 is a glycolipid found on the surface of tumour cells, which is overexpressed in neuroblastoma. Dinutuximab, an IgG1 human/mouse chimeric switch variant of murine monoclonal antibody 14G2a, binds to GD2 and induces antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. The US FDA has recently approved the use of dinutuximab combination therapy for the treatment of high-risk neuroblastoma in paediatric patients. The marketing authorization application for dinutuximab is under regulatory review in the EU, and phase I-III development is underway in several other countries. This article summarizes the milestones in the development of dinutuximab leading to this first approval for use (in combination with granulocyte macrophage colony-stimulating factor, interleukin-2 and 13-cis retinoic acid) in the treatment of paediatric patients with high-risk neuroblastoma who achieve at least partial response to prior first-line multiagent, multimodality therapy.

Dysregulated Expression of Glycolipids in Tumor Cells: From Negative Modulator of Anti-tumor Immunity to Promising Targets for Developing Therapeutic Agents

Glycolipids are complex molecules consisting of a ceramide lipid moiety linked to a glycan chain of variable length and structure. Among these are found the gangliosides, which are sialylated glycolipids ubiquitously distributed on the outer layer of vertebrate plasma membranes. Changes in the expression of certain species of gangliosides have been described to occur during cell proliferation, differentiation, and ontogenesis. However, the aberrant and elevated expression of gangliosides has been also observed in different types of cancer cells, thereby promoting tumor survival. Moreover, gangliosides are actively released from the membrane of tumor cells, having a strong impact on impairing anti-tumor immunity. Beyond the undesirable effects of gangliosides in cancer cells, a substantial number of cancer immunotherapies have been developed in recent years that have used gangliosides as the main target. This has resulted in successful immune cell- or antibody-responses against glycolipids, with promising results having been obtained in clinical trials. In this review, we provide a general overview on the metabolism of glycolipids, both in normal and tumor cells, as well as examining glycolipid-mediated immune modulation and the main successes achieved in immunotherapies using gangliosides as molecular targets.

Ex vivo induction of antitumor DEC-205+ CD11c+ cells in a murine neuroblastoma model by co-stimulation with doxorubicin, lipopolysaccharide and interleukin-4

The antigen-presenting capacity of specific cells and tumor immunogenicity involved in innate cellular immunity are important for initiating an antitumor response to advanced neuroblastoma. The present study was performed to establish a method of producing antigen-presenting cells that induced an immune response to murine neuroblastoma cells through culture with neuroblastoma cells that had undergone immunogenic cell death. Immunogenic death of neuro-2a murine neuroblastoma cells was induced by exposure to doxorubicin. Mouse bone marrow cells were cultured in medium containing granulocyte-macrophage colony-stimulating factor, followed by the addition of doxorubicin-treated neuro-2a cells to the culture with or without lipopolysaccharide (LPS) and/or interleukin-4. Subsequently, cluster of differentiation (CD) 8α⁺ lymphocytes were co-cultured with neuro-2a cells and the adherent bone marrow cells obtained by the above procedure to evaluate CD8α⁺ lymphocyte proliferation and interferon-γ production. Furthermore, the surface antigen profile of adherent bone marrow cells was analyzed by flow cytometry. When adherent bone marrow cells were treated with LPS and/or interleukin-4, followed by co-culture with CD8α⁺ lymphocytes and neuro-2a cells, interferon-γ production by the CD8α⁺ cells increased in response to anti-CD3/CD28 antibody stimulation. CD11c major histocompatibility complex II (MHC II) double-positive cells were increased among adherent cells derived from cultured bone marrow cells. These cells were positive for DEC-205, but not CD8α. These findings suggest that co-culture of bone marrow-derived cells with tumor cells (that have undergone immunogenic death by exposure to doxorubicin) plus stimulation by LPS and interleukin-4 induces antigen-presenting cells that can evoke an immune response to neuroblastoma. Bone marrow-derived DEC-205⁺ CD11c⁺ MHC II⁺ dendritic cells are key antigen-presenting cells in the induction of an immune response following phagocytosis of doxorubicin-treated neuroblastoma cells.

Retinoids and rexinoids in cancer prevention: from laboratory to clinic

Early in the age of modern medicine the consequences of vitamin A deficiency drew attention to the fundamental link between retinoid-dependent homeostatic regulation and malignant hyperproliferative diseases. The term "retinoid" includes a handful of endogenous and a large group of synthetic derivatives of vitamin A. These multifunctional lipid-soluble compounds directly regulate target genes of specific biological functions and critical signaling pathways to orchestrate complex functions from vision to development, metabolism, and inflammation. Many of the retinoid activities on the cellular level have been well characterized and translated to the regulation of processes like differentiation and cell death, which play critical roles in the outcome of malignant transformation of tissues. In fact, retinoid-based differentiation therapy of acute promyelocytic leukemia was one of the first successful examples of molecularly targeted treatment strategies. The selectivity, high receptor binding affinity and the ability of retinoids to directly modulate gene expression programs present a distinct pharmacological opportunity for cancer treatment and prevention. However, to fully exploit their potential, the adverse effects of retinoids must be averted. In this review we provide an overview of the biology of retinoid (activated by nuclear retinoic acid receptors [RARs]) and rexinoid (engaged by nuclear retinoid X receptors [RXRs]) action concluded from a long line of preclinical studies, in relation to normal and transformed states of cells. We will also discuss the past and current uses of retinoids in the treatment of malignancies, the potential of rexinoids in the cancer prevention setting, both as single agents and in combinations.

N-linked glycan profiling in neuroblastoma cell lines

Although MYCN amplification has been associated with aggressive neuroblastoma, the molecular mechanisms that differentiate low-risk, MYCN-nonamplified neuroblastoma from high-risk, MYCN-amplified disease are largely unknown. Genomic and proteomic studies have been limited in discerning differences in signaling pathways that account for this heterogeneity. N-Linked glycosylation is a common protein modification resulting from the attachment of sugars to protein residues and is important in cell signaling and immune response. Aberrant N-linked glycosylation has been routinely linked to various cancers. In particular, glycomic markers have often proven to be useful in distinguishing cancers from precancerous conditions. Here, we perform a systematic comparison of N-linked glycomic variation between MYCN-nonamplified SY5Y and MYCN-amplified NLF cell lines with the aim of identifying changes in sugar abundance linked to high-risk neuroblastoma. Through a combination of liquid chromatography-mass spectrometry and bioinformatics analysis, we identified 16 glycans that show a statistically significant change in abundance between NLF and SY5Y samples. Closer examination revealed the preference for larger (in terms of total monosaccharide count) and more sialylated glycan structures in the MYCN-amplified samples in comparison to smaller, nonsialylated glycans that are more dominant in the MYCN-nonamplified samples. These results offer clues for deriving marker candidates for accurate neuroblastoma risk diagnosis.

Adult neuroblastoma complicated by increased intracranial pressure: a case report and review of the literature

Neuroblastoma is the third most commonly occurring malignancy of the pediatric population, although it is extremely rare in the adult population. In adults, neuroblastoma is often metastatic and portends an extremely poor overall survival. Our case report documents metastatic neuroblastoma occurring in a healthy 29-year-old woman whose course was complicated by an unusual presentation of elevated intracranial pressures. The patient was treated with systemic chemotherapy, I¹³¹ metaiodobenzylguanidine (MIBG) radiotherapy, and autologous stem cell transplant (SCT). Unfortunately the patient's response to therapy was limited and she subsequently died. We aim to review neuroblastoma in the context of increased intracranial pressure and the limited data of neuroblastoma occurring in the adult population, along with proposed treatment options.

Molecular profiling of childhood cancer: Biomarkers and novel therapies

BACKGROUND

Technological advances including high-throughput sequencing have identified numerous tumor-specific genetic changes in pediatric and adolescent cancers that can be exploited as targets for novel therapies.

SCOPE OF REVIEW

This review provides a detailed overview of recent advances in the application of target-specific therapies for childhood cancers, either as single agents or in combination with other therapies. The review summarizes preclinical evidence on which clinical trials are based, early phase clinical trial results, and the incorporation of predictive biomarkers into clinical practice, according to cancer type.

MAJOR CONCLUSIONS

There is growing evidence that molecularly targeted therapies can valuably add to the arsenal available for treating childhood cancers, particularly when used in combination with other therapies. Nonetheless the introduction of molecularly targeted agents into practice remains challenging, due to the use of unselected populations in some clinical trials, inadequate methods to evaluate efficacy, and the need for improved preclinical models to both evaluate dosing and safety of combination therapies.

GENERAL SIGNIFICANCE

The increasing recognition of the heterogeneity of molecular causes of cancer favors the continued development of molecularly targeted agents, and their transfer to pediatric and adolescent populations.

Glycobiology of neuroblastoma: impact on tumor behavior, prognosis, and therapeutic strategies

Neuroblastoma (NB), accounting for 10% of childhood cancers, exhibits aberrant cell-surface glycosylation patterns. There is evidence that changes in glycolipids and protein glycosylation pathways are associated to NB biological behavior. Polysialic acid (PSA) interferes with cellular adhesion, and correlates with NB progression and poor prognosis, as well as the expression of sialyltransferase STX, the key enzyme responsible for PSA synthesis. Galectin-1 and gangliosides, overexpressed and actively shedded by tumor cells, can modulate normal cells present in the tumor microenvironment, favoring angiogenesis and immunological escape. Different glycosyltransferases are emerging as tumor markers and potential molecular targets. Immunotherapy targeting disialoganglioside GD2 rises as an important treatment option. One anti-GD2 antibody (ch14.18), combined with IL-2 and GM-CSF, significantly improves survival for high-risk NB patients. This review summarizes our current knowledge on NB glycobiology, highlighting the molecular basis by which carbohydrates and protein–carbohydrate interactions impact on biological behavior and patient clinical outcome.

Validated detection of human anti-chimeric immune responses in serum of neuroblastoma patients treated with ch14.18/CHO

Human/mouse chimeric monoclonal antibody (mAb) ch14.18/CHO is directed against disialoganglioside GD2. Activity and efficacy of this mAb are currently determined in ongoing clinical Phase II and -III studies in high-risk neuroblastoma (NB). Based on the chimeric nature of this mAb, some patients may develop a human anti-chimeric immune response (Mirick et al., 2004) which impacts on pharmacokinetics and may induce anti-anti-idiotype (Id) mAb with a potential survival benefit. Therefore, a validated method of quantitative detection of human anti-chimeric antibodies (HACA) in serum samples of NB patients treated with ch14.18/CHO is an important tool for monitoring of clinical trials. Here, we report a validated sandwich enzyme-linked immunosorbent assay (ELISA) according to the one arm binding principle using ch14.18/CHO as a capture mAb and biotinylated ch14.18/CHO mAb for detection. Ganglidiomab, a monoclonal anti-Id Ab to ch14.18/CHO (Lode et al., 2013), was used as a standard for assay validation and HACA quantification. Systematic evaluation of the established ELISA procedure revealed an optimal serum sample dilution factor of 1:160. Assay validation was accomplished with a set of tailored quality controls (QC) containing distinct concentrations of ganglidiomab (3 and 15μg/ml). The coefficients of variation (CV) for all within-assay and inter-assay measurements using QCs were under 20% and the limit of detection (LOD) was 1.1μg/ml. Three patients (P1, P2, P3) treated with a 10day continuous infusion of 100mg/m(2) of ch14.18/CHO were selected for analysis with this assay. Selection was based on ch14.18/CHO drug level on day 8 in cycle 2 of >10μg/ml (expected) (P1) and of <2μg/ml (unexpected) (P2 and P3). Both patients with unexpected low ch14.18/CHO levels revealed a strong signal in the HACA ELISA. Interestingly, ch14.18/CHO-mediated complement-dependent cytotoxicity (CDC) could not be detected in P2 in contrast to P3 suggesting anti-NB activity even in the presence of HACA. We showed that neither eight freeze-thaw cycles nor storage at room temperature for up to 168h affected HACA stability in serum. In summary, we describe a validated ELISA method suitable for the assessment of HACA in NB patients treated with ch14.18/CHO.

Posterior reversible encephalopathy syndrome in neuroblastoma patients receiving anti-GD2 3F8 monoclonal antibody

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) comprises clinical and radiologic findings with rapid onset and potentially dire consequences. Patients experience hypertension, seizures, headache, visual disturbance, and/or altered mentation. Magnetic resonance imaging reveals edematous changes in the brain (especially in the parietal and occipital lobes). In this report, the authors describe PRES associated with antidisialoganglioside (anti-GD2 ) monoclonal antibody (MoAb) immunotherapy, which is now standard for high-risk neuroblastoma but has not previously been implicated in PRES.

METHODS

Successive clinical trials using the anti-GD2 MoAb 3F8 (a murine immunoglobulin 3 MoAb specific for GD2) for patients with neuroblastoma involved multiple cycles of standard-dose 3F8 (SD-3F8) (20 mg/m2 daily for 5 days per cycle) or 2 cycles of high-dose 3F8 (HD-3F8) (80 mg/m2 daily for 5 days per cycle) followed by cycles of SD-3F8.

RESULTS

PRES was diagnosed in 5 of 215 patients (2.3%), including 3 of 160 (1.9%) who received SD-3F8 and 2 of 55 (3.6%) who received HD-3F8 (P = .6). All 5 patients had a rapid return to clinical-radiologic baseline. PRES occurred in 3 of 26 patients (11.5%) whose prior treatment included external-beam radiotherapy to the brain (2 of 6 patients status-post total body irradiation and 1 of 20 patients status-post craniospinal irradiation) compared with 2 of 189 patients (1.1%) who had not received prior brain irradiation (P = .01). Hypertension, which is strongly linked to PRES, reached grade 3 toxicity in 12 of 215 patients (5.6%), including the 5 patients with PRES and 7 patients without PRES.

CONCLUSIONS

Patients who receive anti-GD2 MoAb immunotherapy should be closely monitored for, and undergo urgent treatment or evaluation of, symptoms that may herald PRES (eg, hypertension or headaches). Prior brain irradiation may be a predisposing factor for PRES with this immunotherapy.