anti-GD2 Immunotherapy Research Articles

Treatment-Related Toxicities During Anti-GD2 Immunotherapy in High-Risk Neuroblastoma Patients.

The introduction of immunotherapy using an anti-GD2 antibody (dinutuximab, ch14.18) has significantly improved survival rates for high-risk neuroblastoma patients. However, this improvement in survival is accompanied by a substantial immunotherapy-related toxicity burden. The primary objective of this study was to describe treatment-related toxicities during immunotherapy with dinutuximab, IL-2, GM-CSF, and isotretinoin. A retrospective, single center analysis of immunotherapy-related toxicities was performed in twenty-six consecutive high-risk neuroblastoma patients who received immunotherapy as maintenance therapy in the Princess Máxima Center (Utrecht, Netherlands). Toxicities were recorded and graded according to the CTCAE. Particular attention was drawn to pain and fever management and toxicities leading to dose modifications of dinutuximab and IL-2. Twenty-three patients (88%) completed all six courses of immunotherapy. Disease progression, isotretinoin-associated liver toxicity, and catheter-related infection in combination with peripheral neuropathy were reasons for immunotherapy discontinuation. The most common grade ≥3 toxicities for courses 1–5, respectively, were pain, catheter-related infections, and fever. In total, 310 grade ≥3 toxicities were recorded in 124 courses. Thirty-three grade 4 toxicities in 19/26 patients and no grade 5 toxicities (death) were seen. Fifty-nine percent of grade ≥3 toxicities were recorded in the two courses with IL-2. Catheter-related bloodstream infections were identified in 81% of patients. Four of these episodes led to intensive care admission followed by full recovery (grade 4).

Intratumoral immunosuppression profiles in 11q-deleted neuroblastomas provide new potential therapeutic targets.

High-risk neuroblastoma (NB) patients with 11q deletion frequently undergo late but consecutive relapse cycles with fatal outcome. To date, no actionable targets to improve current multimodal treatment have been identified. We analyzed immune microenvironment and genetic profiles of high-risk NB correlating with 11q immune status. We show in two independent cohorts that 11q-deleted NB exhibits various immune inhibitory mechanisms, including increased CD4+ resting T cells and M2 macrophages, higher expression of programmed death-ligand 1, interleukin-10, transforming growth factor-beta-1, and indoleamine 2,3-dioxygenase 1 (P<0.05), and also higher chromosomal breakages (P≤0.02) and hemizygosity of immunosuppressive miRNAs than MYCN-amplified and other 11q-nondeleted high-risk NB. We also analyzed benefits of maintenance treatment in 83 high-risk stage M NB patients focusing on 11q status, either with standard anti-GD2 immunotherapy (n=50) or previous retinoic acid-based therapy alone (n=33). Immunotherapy associated with higher EFS (50 vs. 30, P=0.028) and OS (72 vs. 52, P=0.047) at 3years in the overall population. Despite benefits from standard anti-GD2 immunotherapy in high-risk NB patients, those with 11q deletion still face poor outcome. This NB subgroup displays intratumoral immune suppression profiles, revealing a potential therapeutic strategy with combination immunotherapy to circumvent this immune checkpoint blockade.

The glycosphingolipid GD2 as an effective but enigmatic target of passive immunotherapy in children with aggressive neuroblastoma (HR-NBL).

Neuroblastoma (NBL), the most frequent and lethal pediatric cancer of children in pre-school age, is considered enigmatic in view of its extreme heterogeneity, from spontaneous regression in the IV-S form to incurable disease in approx. 40% of cases (High Risk, HR-NBL). It has an embryonal origin and a very heterogeneous genomic landscape, hampering the success of targeted strategies. The glycosphingolipid GD2 was shown to be expressed on NBL cells and utilized as target for passive immunotherapy with anti-GD2 antibodies (GD2-IMT). An international protocol was established with GD2-IMT, which increases remission length and survival in HR-NBL. By reviewing the different biological and molecular aspects of NBL and GD2-IMT, this mini-review questions the present lack of association between GD2-IMT and the underlying molecular landscape. The alternative model of Micro-Foci inducing virus (MFV) is presented, since MFV infection can induce extensive genomic aberrations (100X NMYC DNA-amplification). Since this family of viruses uses molecules for cell penetration similar to GD2 (i.e., GM2), it is hypothesized that GD2 is the port-of-entry for MFV and that success of anti-GD2 therapies is also associated to inhibition of this clastogenic virus in HR-NBL.

The Role of Autologous Stem-Cell Transplantation in High-Risk Neuroblastoma Consolidated by anti-GD2 Immunotherapy. Results of Two Consecutive Studies.

Background: Treatment of HR-NB comprise induction, consolidation with autologous stem cell transplant (ASCT) followed by anti-GD2 immunotherapy and isotretinoin. Childrens Oncology Group and SIOPEN studies used dinutuximab and cytokines to treat patients in complete remission or refractory Bone/Bone marrow (B/BM) disease after ASCT. Methods: HR-NB patients referred to Hospital Sant Joan de Déu for anti-GD2 immunotherapy were eligible for two consecutive studies (dinutuximab for EudraCT 2013–004864–69 and naxitamab for 017–001829–40) and naxitamab/Sargramostim CU with or without prior ASCT. Patients enrolled in first complete remission or with primary refractory B/BM disease. We accrued a study population of two groups whose therapy, aside from ASCT, was similar. This is a retrospective analysis of their outcome calculated from study entry. Results: From December 2014–2019, 67 patients were treated with dinutuximab and cytokines (n = 21) in the Hospital Sant Joan de Déu-HRNB-Ch14.18 study or with naxitamab and Sargramostim either in the Ymabs study 201 (n = 12) or CU (n = 34). 23 patients were treated with primary refractory disease in the B/BM (11 with dinutuximab and 12 with naxitamab), and 44 in first CR (10 with dinutuximab and 34 with naxitamab). Study patients included 13 (19.4%) treated following single ASCT and 54 following conventional chemotherapy. Median follow-up for all patients is 16.2 months. Two-year rates for ASCT and non-ASCT patients were, respectively, EFS 64.1% vs. 54.2% (p = 0.28), and OS 66.7% vs. 84.1% (p = 0.81). For the 44 pts in first CR, 2-years rates for ASCT and non-ASCT patients were, respectively, EFS 65.5% vs. 58.7% (p = 0.48), and OS 71.4% vs. 85.4% (p = 0.63). Conclusions: In this retrospective, single center study, ASCT did not provide survival benefit when anti-GD2 immunotherapy was used after induction chemotherapy.

Anti-GD2-IRDye800CW as a targeted probe for fluorescence-guided surgery in neuroblastoma

Neuroblastoma resection represents a major challenge in pediatric surgery, because of the high risk of complications. Fluorescence-guided surgery (FGS) could lower this risk by facilitating discrimination of tumor from normal tissue and is gaining momentum in adult oncology. Here, we provide the first molecular-targeted fluorescent agent for FGS in pediatric oncology, by developing and preclinically evaluating a GD2-specific tracer consisting of the immunotherapeutic antibody dinutuximab-beta, recently approved for neuroblastoma treatment, conjugated to near-infrared (NIR) fluorescent dye IRDye800CW. We demonstrated specific binding of anti-GD2-IRDye800CW to human neuroblastoma cells in vitro and in vivo using xenograft mouse models. Furthermore, we defined an optimal dose of 1 nmol, an imaging time window of 4 days after administration and show that neoadjuvant treatment with anti-GD2 immunotherapy does not interfere with fluorescence imaging. Importantly, as we observed universal, yet heterogeneous expression of GD2 on neuroblastoma tissue of a wide range of patients, we implemented a xenograft model of patient-derived neuroblastoma organoids with differential GD2 expression and show that even low GD2 expressing tumors still provide an adequate real-time fluorescence signal. Hence, the imaging advancement presented in this study offers an opportunity for improving surgery and potentially survival of a broad group of children with neuroblastoma.

Anti-GD2 immunotherapy with the chimeric antibody ch14.18 for high-risk neuroblastoma

Neuroblastoma is the most common extracranial solid tumor in children 0–14 years old. Current risk-adapted treatment programs are based on stratification of patient into three risk groups. 40–50% of patients are stratified into the high-risk group. The prognosis in high-risk patients remains poor (the probability of long-term survival is less than 50%), despite the use of aggressive multimodal therapy, including high-dose chemotherapy and autologous hematopoietic stem cell transplantation. In most cases tumor cells in neuroblastoma express disialoganglioside GD2, which is a possible target for immunotherapy. Over the past 30 years, GD2-directed chimeric monoclonal antibodies ch14.18 have been introduced into clinical practice. A number of clinical studies have shown an improvement in the prognosis in patients with high-risk neuroblastoma, when using monoclonal antibodies ch14.18, primarily due to the eradication of the minimal residual population of tumor cells resistant to standard chemotherapy. This literature review summarizes the international experience in the use of monoclonal antibodies ch14.18 from early phases of clinical trials to large randomized trials, which allowed immunotherapy to be considered as an important component of multimodal therapy for high-risk neuroblastoma. Future prospects for the use and place of immunotherapy in first-line therapy of high-risk neuroblastoma and in relapsed setting are considered.

Anti-GD2 antibodies immunotherapy in patients with high risk neuroblastoma

Anti-GD2 antibodies immunotherapy in patients with high risk neuroblastoma

In Vivo Validation of Trogocytosis in Neuroblastoma: A Potential Novel Mechanism of Resistance to Anti-GD2 Immunotherapy

In Vivo Validation of Trogocytosis in Neuroblastoma: A Potential Novel Mechanism of Resistance to Anti-GD2 Immunotherapy

Abstract 1293: MYC transcription activation mediated by OCT4 as a mechanism of resistance to 13-cisRA-mediated differentiation in neuroblastoma

Abstract MYCN genomic amplification is one of the risk factors in neuroblastoma. 13-cis retinoic acid (13-cisRA), a differentiating agent, down-regulates MYCN protein and is part of neuroblastoma maintenance therapy. Despite the improvement in clinical outcome with 13-cisRA, anti-GD2 monoclonal antibody plus cytokine immunotherapy given in first response ~40% of high-risk neuroblastoma patients still die of recurrent disease. Although MYC genomic amplification is rare in neuroblastoma (~1%), 11% of neuroblastoma primary tumors collected at diagnosis (Dx) have high c-MYC protein suggesting that MYC transcriptional activation rather than its gene amplification drives such tumors. Here, we sought to investigate the role of MYC oncogene in progressive disease (PD) and to molecularly characterize mechanisms of MYC expression in neuroblastoma. We report transcriptional activation of MYC medicated by the OCT4 (encoded by POU5F1), functionally replacing MYCN in 13-cisRA-resistant progressive disease neuroblastoma. In large panels of neuroblastoma patient-derived cell lines (19 Dx and 16 PD) and patient-derived xenograft PDX models (8 Dx and 9 PD), we confirmed that c-MYC expression levels were higher in PD relative to Dx lines (P = 0.0005). We identified OCT4 and TCF3 as transcription factors highly expressed in neuroblastoma cells with high c-MYC. Subsequently, we confirmed two novel OCT4-binding sites (including OBS1 and OBS2) located in the MYC promoter/enhancer region: -1209 to -1140 and found that OCT4 NH2-terminal domain (NTD) and POU specific domain (POUs) are critical for MYC transcriptional activation. To identify kinases that is associated with OCT4-induced c-MYC activation, we used mass spectrometry and PhosphoMotif Finder® and identified MAPKAPK2 (MK2) as one of the upstream kinases that can bind to and directly regulate the OCT4 biological function by phosphorylation at its amino acid Ser111 residue to transcriptionally activate MYC expression. The data in 175 MYCN non-amplified high-risk primary tumors (TARGET database) showed that MAPKAPK2 positively correlated with MYC expression (P &amp;lt; 0.001) and overall survival was lower (P &amp;lt; 0.001) for patients with high MAPKAPK2. Also, OCT4, MK2, and c-MYC were higher in PD relative to Dx neuroblastomas models. Functional studies by gene knockdown of the POU5F1 or MAPKAPK2 using shRNAs showed decreased c-MYC expression, inhibition of cell proliferation, and restoring neurite outgrowth in response to 13-cisRA. In conclusion, high c-MYC independent of genomic amplification, not MYCN amplification, is associated with disease progression in neuroblastoma. The MK2-mediated OCT4 transcriptional activation is a novel mechanism for MYC activation in PD neuroblastoma and provides a potential novel therapeutic target. Citation Format: Sung Jen Wei, Thinh H. Nguyen, Dustin G. Mook, Monish R. Makena, Dattesh Verlekar, Ashly Hindle, Gloria Martinez, Shengping Yang, Hiroyuki Shimada, C. Patrick Reynolds, Min H. Kang. MYC transcription activation mediated by OCT4 as a mechanism of resistance to 13-cisRA-mediated differentiation in neuroblastoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1293.

Anti-GD2 induced allodynia in rats can be reduced by pretreatment with DFMO.

Anti-GD2 therapy with dinutuximab is effective in improving the survival of high-risk neuroblastoma patients in remission and after relapse. However, allodynia is the major dose-limiting side effect, hindering its use for neuroblastoma patients at higher doses and for other GD2-expressing malignancies. As polyamines can enhance neuronal sensitization, including development of allodynia and other forms of pathological pain, we hypothesized that polyamine depletion might prove an effective strategy for relief of anti-GD2 induced allodynia. Sprague-Dawley rats were allowed to drink water containing various concentrations of difluoromethylornithine (DFMO) for several days prior to behavioral testing. Anti-GD2 (14G2a) was injected into the tail vein of lightly sedated animals and basal mechanical hindpaw withdrawal threshold assessed by von Frey filaments. Endpoint serum DFMO and polyamines, assessed 24h after 14G2a injection, were measured by HPLC and mass spectrometry. An i.v. injection of 14G2a causes increased paw sensitivity to light touch in this model, a response that closely mimics patient allodynia. Animals allowed to drink water containing 1% DFMO exhibited a significant reduction of 14G2a-induced pain sensitivity (allodynia). Increasing the dosage of the immunotherapeutic increased the magnitude (intensity and duration) of the pain behavior. Administration of DFMO attenuated the enhanced sensitivity. Consistent with the known actions of DFMO on ornithine decarboxylase (ODC), serum putrescene and spermidine levels were significantly reduced by DFMO, though the decrease in endpoint polyamine levels did not directly correlate with the behavioral changes. Our results demonstrate that DFMO is an effective agent for reducing anti-GD2 -induced allodynia. Using DFMO in conjunction with dinutuximab may allow for dose escalation in neuroblastoma patients. The reduction in pain may be sufficient to allow new patient populations to utilize this therapy given the more acceptable side effect profile. Thus, DFMO may be an important adjunct to anti-GD2 immunotherapy in addition to a role as a potential anti-cancer therapeutic.

Abstract IA10: Activating innate and adaptive immunity to improve outcome for “cold” tumors

Abstract Unlike some adult cancers, most pediatric cancers are considered immunologically cold and generally less responsive to immunotherapy. Anti-GD2 mAb plus cytokine-based immunotherapy has already been incorporated into standard-of-care treatment for pediatric patients with high-risk neuroblastoma achieving remission. However, overall survival remains poor. We are pursuing clinical and preclinical studies to engage innate and adaptive immune responses against immunologically cold tumors. In a recent trial of adjuvant/neoadjuvant anti-GD2 mAb + IL2 (in the form of the hu14.18-IL2 immunocytokine) for advanced resectable melanoma, we evaluated whole-genome transcriptomics (using RNAseq determined immunologic signatures found to be predictive of outcome for patients with neuroblastoma) on resected tumors. The immunologic signatures were highly correlated with overall survival and relapse-free survival for tumors obtained 2 weeks after starting hu14.18-IL2, but not for tumors obtained 2 weeks before starting hu14.18-IL2. In a “functionally cold” mouse melanoma model, we found that radiation and hu14.18-IL2 immunocytokine generate an in situ vaccination-induced adaptive immune response in syngeneic mice bearing large tumors. In contrast, this same approach was not effective in mice bearing a very cold, low-tumor-mutation burden, MYCN driven syngeneic neuroblastoma (9464D-GD2). The addition of checkpoint blockade (IgG2a anti-CTLA-4) was not able to induce tumor eradication. However, the further addition of CpG (as a “danger signal”) and agonist anti-CD40 mAb (as an activator of effector macrophages and of dendritic cells) resulted in tumor-free mice with immune memory. These results suggest that immune activation, with “off the shelf” reagents, may be applicable to the treatment of cold cancers, via innate/adaptive immune engagement. They also suggest that monitoring of intratumoral immune activation could potentially become a useful predictor of which patients will respond to their therapy and which will require additional or alternate therapy. Citation Format: Paul M. Sondel. Activating innate and adaptive immunity to improve outcome for “cold” tumors [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr IA10.

The role of autologous stem-cell transplantation in high-risk neuroblastoma consolidated by anti-GD2 immunotherapy: Results of 2 consecutive studies in a single referral institution.

10539 Background: Treatment of high-risk NB within the major international cooperative groups (COG and SIOP) comprise intensive induction, consolidation with high dose chemotherapy and autologous stem cell rescue (ASCR) followed by anti-GD2 immunotherapy and isotretinoin as maintenance therapy. In the COG studies dinutuximab and cytokines (GM-CSF and IL-2) were used to treat patients in complete remission (CR) after ASCR whereas SIOPEN studies used dinutuximab-beta plus/minus IL-2 and included patients with responsive (no progression 109 days after ASCR) but refractory (skeletal metaiodobenzylguanidine positivity with three or fewer areas of abnormal uptake). Methods: Since December 2014, HR-NB patients referred to HSJD were eligible for consolidation with anti-GD2/GM-CSF immunotherapy in 2 consecutive studies (dinutuximab for EudraCT 2013-004864-69 and naxitamab for 017-001829-40) and naxitamab/GM-CSF compassionate use (CU) with or without prior ASCR. Patients were enrolled in 1st CR or with primary refractory bone/bone marrow (B/BM) disease. We accrued a study population of two groups whose consolidative therapy, aside from ASCR, was similar: anti-GD2 (dinutuximab or naxitamab) antibodies + GM-CSF and local radiotherapy. This is a retrospective analysis of their event-free survival (EFS) and overall survival (OS) calculated from study entry. Results: From Dec 14 til Dec 19, 67 study patients were treated with the COG (dinutuximab + GM-CSF+ IL-2 + RA) regimen (n = 21) in the HSJD-HRNB-Ch14.18 study or with Naxitamab and GM-CSF in the Ymabs study 201 (n = 12) or CU (n = 34). 23 patients were treated with primary refractory disease in the B/BM, and 44 in 1st CR. The 67 study patients included 13 (19%) treated following single ASCR and 54 following induction chemotherapy and surgery. Median follow-up for all surviving patients is 16.2 months. Two-year rates for ASCR and non-ASCR patients were, respectively: EFS 64% vs. 54% (p = 0.28), and OS 66.7% vs. 84% (p = 0.8). For the 44 pts in 1st CR, 2-year rates for ASCR and non-ASCR patients were, respectively: EFS 65% vs. 58% (p = 0.48), and OS 71% vs. 85% (p = 0.63). Conclusions: In this retrospective, single center study, ASCR did not provide survival benefit when anti-GD2 + GM-CSF based immunotherapy was used for consolidation after dose-intensive conventional chemotherapy.

Passive immunotherapy experience in patients with high-risk neuroblastoma

Introduction. Despite great achievements in treatment of neuroblastoma (NB) for the last decades, the outcome for high-risk patients remains adverse: 5-year overall survival does not exceed 30 %. The purpose of the study. Demonstration of anti-GD2 monoclonal antibodies immunotherapy and assessment of its toxicity in patients treated at the N.N. Petrov National Medical Research Center of Oncology. Material and methods . Anti-GD2 antibodies have been used as post consolidation in 8 high-risk NB patients aged from 1.8 to 10 years old since 2018 to present. After completion of induction chemotherapy according to NB-2004protocol, all patients underwent local tumor control with surgery and additional local radiotherapy in 3 cases. Four patients were received a single high-dose chemotherapy with autologous bone marrow transplant; one patient was received high-dose chemotherapy with haploidentical stem cell transplantation. Tree patients were received the tandem high-dose chemotherapy with autologous stem-cell transplantation. Two (25 %) patients had a primary resistant NB, and remission was achieved only after three lines of chemotherapy. One (12.5 %) child was diagnosed with a recurrence of NB of a solitary lesion in the right frontal lobe of the brain 8 months after the completion of the treatment according to the NB-2004protocol. Thus, 3 people from the study group received anti-GD2 antibodies after applying several lines of chemotherapy. All children at the start ofanti-GD2 antibody therapy were no progressive disease. Results. A total of 21 courses of immunotherapy were conducted. No progressive disease was the main condition of anti-GD2 antibodies immunotherapy, such patients were excluded from the research. The antibodies were administered as a continuous infusion during 10 days (240 hours) in a daily dose of 10 mg/m2. When using the antibodies, the following adverse events were noted: hematotoxicity in 90.4 % cases, fever in 71.4 %, diarrhea in 23.8 %, capillary leak syndrome in 19 % patients, neuropathy and cytokine release syndrome were detected in 14.9 % cases, pain — in 9.5 % patients. All complications were tolerable and cured, dose reduction was not required. Now 7patients are in remission, in one patient after the first cycle of immunotherapy progressive disease was revealed. Conclusions. The immunotherapy monoclonal anti-GD2 antibodies are well tolerable and safe procedure with adequate maintenance therapy. According to international experience the efficiency does not raise her doubts.

NCMP-03. AN UNUSUAL CASE OF NEUROBLASTOMA ASSOCIATED OMS: HIGH RISK DISEASE REQUIRING IMMUNOTHERAPY

Abstract INTRODUCTION Opsoclonus-myoclonus-ataxia syndrome (OMS) is a rare paraneoplastic syndrome (PNS) typically associated with low-risk pediatric neuroblastoma (NB). Overall survival is excellent but patients are at risk for long-term neurologic sequelae. As with many PNS, the etiology of NB-associated OMS is thought to be immune mediated and patients are managed with immunosuppressive therapy. The use of other immunotherapy such as checkpoint inhibitors for advanced stage cancers has been associated with sporadic reports of the development of PNS. We report a case of a child with NB-associated OMS who received anti-GD2 antibody immunotherapy for advanced relapsed NB without exacerbation of OMS. While the mechanism of action of anti-GD2 is unique, this case demonstrates that further study is required to understand which patients are at risk for PNS development/flare during therapy for advanced stage cancers. CASE: Our patient presented at 16 months of age with acute onset of tremors, irritability and ataxia and was diagnosed with OMS; at that time, evaluation revealed intermediate risk stage 4 neuroblastoma which was treated with 4 cycles of chemotherapy with complete response. His OMS was managed initially with high dose dexamethasone, followed by monthly IVIG, ACTH and rituximab with improvement in neurologic symptoms. The patient developed NB relapse (stage 4) 18 months after completion of initial chemotherapy and received chemotherapy and anti-GD2 antibody immunotherapy. Through this second course of therapy he continued to wean his immunosuppressive anti-OMS therapy without flare of his neurologic symptoms. DISCUSSION We present an unusual case of a child with NB-associated OMS whose OMS symptoms did not flare despite the use of immunotherapy to treat relapsed stage 4 disease. CONCLUSION While immunosuppression is used to treat OMS and other paraneoplastic syndromes, the use of immunotherapy to treat the underlying malignancy may be tolerated. Further study is needed.

Treatment-Resistant Neuroblastoma Populations after Anti-GD2 Immunotherapy

Zamora, Abigail K. MD; Zobel, Michael J. MD; Sun, Jianping MD; Sheard, Michael A. PhD; Seeger, Robert C. MD, MS; Kim, Eugene S. MD, FACS, FAAP Author Information

Anti-CD105 Antibody Eliminates Tumor Microenvironment Cells and Enhances Anti-GD2 Antibody Immunotherapy of Neuroblastoma with Activated Natural Killer Cells.

We determined whether elimination of CD105+ cells in the tumor microenvironment (TME) with anti-CD105 antibodies enhanced anti-disialoganglioside (GD2) antibody dinutuximab therapy of neuroblastoma when combined with activated natural killer (aNK) cells. The effect of MSCs and monocytes on antibody-dependent cellular cytotoxicity (ADCC) mediated by dinutuximab with aNK cells against neuroblastoma cells was determined in vitro. ADCC with anti-CD105 mAb TRC105 and aNK cells against MSCs, monocytes, and endothelial cells, which express CD105, was evaluated. Anti-neuroblastoma activity in immunodeficient NSG mice of dinutuximab with aNK cells without or with anti-CD105 mAbs was determined using neuroblastoma cell lines and a patient-derived xenograft. ADCC mediated by dinutuximab with aNK cells against neuroblastoma cells in vitro was suppressed by addition of MSCs and monocytes, and dinutuximab with aNK cells was less effective against neuroblastomas formed with coinjected MSCs and monocytes in NSG mice than against those formed by tumor cells alone. Anti-CD105 antibody TRC105 with aNK cells mediated ADCC against MSCs, monocytes, and endothelial cells. Neuroblastomas formed in NSG mice by two neuroblastoma cell lines or a patient-derived xenograft coinjected with MSCs and monocytes were most effectively treated with dinutuximab and aNK cells when anti-human (TRC105) and anti-mouse (M1043) CD105 antibodies were added, which depleted human MSCs and murine endothelial cells and macrophages from the TME. Immunotherapy of neuroblastoma with anti-GD2 antibody dinutuximab and aNK cells is suppressed by CD105+ cells in the TME, but suppression is overcome by adding anti-CD105 antibodies to eliminate CD105+ cells.

Positron Emission Tomography Detects In Vivo Expression of Disialoganglioside GD2 in Mouse Models of Primary and Metastatic Osteosarcoma.

The cell membrane glycolipid GD2 is expressed by multiple solid tumors, including 88% of osteosarcomas and 98% of neuroblastomas. However, osteosarcomas are highly heterogeneous, with many tumors exhibiting GD2 expression on <50% of the individual cells, while some tumors are essentially GD2-negative. Anti-GD2 immunotherapy is the current standard of care for high-risk neuroblastoma, but its application to recurrent osteosarcomas, for which no effective therapies exist, has been extremely limited. This is, in part, because the standard assays to measure GD2 expression in these heterogeneous tumors are not quantitative and are subject to tissue availability and sampling bias. To address these limitations, we evaluated a novel, sensitive radiotracer [64Cu]Cu-Bn-NOTA-hu14.18K322A to detect GD2 expression in osteosarcomas (six patient-derived xenografts and one cell line) in vivo using positron emission tomography (PET). Tumor uptake of the radiolabeled, humanized anti-GD2 antibody [64Cu]Cu-Bn-NOTA-hu14.18K322A was 7-fold higher in modestly GD2-expressing osteosarcomas (32% GD2-positive cells) than in a GD2-negative tumor (9.8% vs. 1.3% of the injected dose per cc, respectively). This radiotracer also identified lesions as small as 29 mm3 in a 34% GD2-positive model of metastatic osteosarcoma of the lung. Radiolabeled antibody accumulation in patient-derived xenografts correlated with GD2 expression as measured by flow cytometry (Pearson r = 0.88, P = 0.01), distinguishing moderately GD2-expressing osteosarcomas (32%-69% GD2-positive cells) from high GD2 expressors (>99%, P < 0.05). These results support the utility of GD2 imaging with PET to measure GD2 expression in osteosarcoma and thus maximize the clinical impact of anti-GD2 immunotherapy. SIGNIFICANCE: In situ assessment of all GD2-positive osteosarcoma sites with a novel PET radiotracer could significantly impact anti-GD2 immunotherapy patient selection and enable noninvasive probing of correlations between target expression and therapeutic response.

Anti-GD2 antibody-containing immunotherapy postconsolidation therapy for people with high-risk neuroblastoma treated with autologous haematopoietic stem cell transplantation.

Neuroblastoma is a rare malignant disease that primarily affects children. The tumours mainly develop in the adrenal medullary tissue, and an abdominal mass is the most common presentation. High-risk disease is characterised by metastasis and other primary tumour characteristics resulting in increased risk for an adverse outcome. The GD2 carbohydrate antigen is expressed on the cell surface of neuroblastoma tumour cells and is thus a promising target for anti-GD2 antibody-containing immunotherapy. To assess the efficacy of anti-GD2 antibody-containing postconsolidation immunotherapy after high-dose chemotherapy (HDCT) and autologous haematopoietic stem cell transplantation (HSCT) compared to standard therapy after HDCT and autologous HSCT in people with high-risk neuroblastoma. Our primary outcomes were overall survival and treatment-related mortality. Our secondary outcomes were progression-free survival, event-free survival, early toxicity, late non-haematological toxicity, and health-related quality of life. We searched the electronic databases CENTRAL (2018, Issue 9), MEDLINE (PubMed), and Embase (Ovid) on 20 September 2018. We searched trial registries and conference proceedings on 28 October 2018. Further searches included reference lists of recent reviews and relevant articles as well as contacting experts in the field. There were no limits on publication year or language. Randomised controlled trials evaluating anti-GD2 antibody-containing immunotherapy after HDCT and autologous HSCT in people with high-risk neuroblastoma. Two review authors independently performed study selection, abstracted data on study and participant characteristics, and assessed risk of bias and GRADE. Any differences were resolved by discussion, with third-party arbitration unnecessary. We performed analyses according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions. We used the five GRADE considerations, that is study limitations, consistency of effect, imprecision, indirectness, and publication bias, to judge the quality of the evidence. We identified one randomised controlled trial that included 226 people with high-risk neuroblastoma who were pre-treated with autologous HSCT. The study randomised 113 participants to receive immunotherapy including isotretinoin, granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-2, and ch14.18, a type of anti-GD2 antibody also known as dinutuximab. The study randomised another 113 participants to receive standard therapy including isotretinoin.The results on overall survival favoured the dinutuximab-containing immunotherapy group (hazard ratio (HR) 0.50, 95% confidence interval (CI) 0.31 to 0.80; P = 0.004). The results on event-free survival also favoured the dinutuximab-containing immunotherapy group (HR 0.61, 95% CI 0.41 to 0.92; P = 0.020). Randomised data on adverse events were not reported separately. The study did not report progression-free survival, late non-haematological toxicity, and health-related quality of life as separate endpoints. We graded the quality of the evidence as moderate. The evidence base favours dinutuximab-containing immunotherapy compared to standard therapy concerning overall survival and event-free survival in people with high-risk neuroblastoma pre-treated with autologous HSCT. Randomised data on adverse events are lacking, therefore more research is needed before definitive conclusions can be made regarding this outcome.

Advances in Anti-GD2 Immunotherapy for Treatment of High-risk Neuroblastoma.

Neuroblastoma (NBL) is the most common extracranial solid tumor in pediatrics, yet overall survival is poor for high-risk cases. Immunotherapy regimens using a tumor-selective antidisialoganglioside (anti-GD2) monoclonal antibody (mAb) have been studied for several decades now, but have only recently been incorporated into standard of care treatment for patients with high-risk NBL with clear benefit. Here we review a brief history of anti-GD2-based immunotherapy, current areas of neuroblastoma research targeting GD2, and potential diagnostic and therapeutic uses targeting GD2.

Abstract 3831: Development of near-infrared photoimmunotherapy targeting GD2-positive neuroblastoma

Abstract Background: Neuroblastoma (NB) is a primary malignant tumor of the peripheral sympathetic nervous system. Despite the recent advances in the treatment of NB, patients with high-risk NB still have poor prognosis. Immunotherapy using anti-GD2 monoclonal antibody (mAb), which binds to disialoganglioside GD2 on the surface of NB cells, has recently become a standard treatment for high-risk NB. However, the therapeutic efficacy of anti-GD2 mAb is insufficient in many clinical trials. Therefore, the enhancement of therapeutic potential of anti-GD2 mAb is needed to improve the clinical outcome of patients with high-risk NB. Near-infrared photoimmunotherapy (NIR-PIT) is a promising antitumor strategy to enhance the therapeutic potential of immunotherapy using an antibody-photoabsorber conjugate (APC). In this study, we investigated the therapeutic efficacy of anti-GD2-based NIR-PIT using anti-GD2 mAb conjugated to the photoabsorber IR700 (anti-GD2-IR700) in human NB cells. Methods: We used 3 human NB cell lines, including IMR-32, CHP-134 and SK-N-SH. The expression of GD2 on the cell surface of NB cells was analyzed by flow cytometric analysis. Anti-GD2-IR700 was synthesized by incubating anti-GD2 mAb and IR700. The mixture was purified with a Sephadex G50 column. The antitumor effect of anti-GD2-IR700 was evaluated using XTT assay. NB cells were incubated with anti-GD2-IR700, anti-GD2 mAb or PBS and NIR light was irradiated at 2.0J/cm2. Results: IMR-32 and CHP-134 cells, but not SK-N-SH cells, expressed GD2 protein on the cell surface. In GD2-positive IMR-32 and CHP-134 cells, administration of anti-GD2-IR700 significantly suppressed the cell viability compared to anti-GD2 mAb or PBS when combined with NIR light irradiation. In contrast, in GD2-negative SK-N-SH cells, anti-GD2-IR700 showed no significant inhibition of cell viability in combination with NIR light irradiation. Conclusion: These results suggest that NIR-PIT using an anti-GD2-IR700 is a promising antitumor strategy to promote the therapeutic efficacy of anti-GD2 immunotherapy for high-risk NB. Citation Format: Hiroshi Nouso, Hiroshi Tazawa, Terutaka Tanimoto, Morimichi Tani, Takanori Oyama, Hiroaki Sato, Kazuhiro Noma, Shunsuke Kagawa, Hisataka Kobayashi, Takuo Noda, Toshiyoshi Fujiwara. Development of near-infrared photoimmunotherapy targeting GD2-positive neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3831.