Immune Reconstitution Following Autologous Stem Cell Transplantation in Patients with High-Risk Neuroblastoma at the Time of Immunotherapy

Immune reconstitution after transplantation of autologous peripheral stem cells in children: a comparison between CD34+ selected and nonmanipulated grafts

BACKGROUND AND AIMS

High-dose chemotherapy (HDC) followed by autologous stem cell transplantation (ASCT) improves the prognosis in pediatric patients with several solid tumors and lymphomas. Little is known about the reconstitution of the immune system after ASCT and the influence of CD34+ cell selection on the reconstitution in pediatric patients.

METHODS

Between 1990 and 2001, 94 pediatric patients with solid tumors and lymphomas received autologous CD34+ selected or unmanipulated peripheral stem cells after HDC. CD34+ selection was carried out with magnetic microbeads. The absolute numbers of T cells, B cells and natural killer (NK) cells were measured and compared in both groups at various time points post-transplant.

RESULTS

Recovery of T cells was significantly faster in the unmanipulated group at day 30, with no significant difference later on. Reconstitution of B and NK cells was similar in both groups without significant differences at any time. The CD34+-selected group was divided into patients receiving less or more than 5.385 × 106/kg CD34+ cells. Patients in the CD34+ high-dose group displayed significantly faster reconstitutions of neutrophiles and lymphocyte subsets than the CD34+ low-dose group.

CONCLUSIONS

Engraftment and reconstitution of leukocytes, B cells and NK cells after transplantation of CD34+ selected stem cells were comparable to that in patients receiving unmanipulated grafts. T-cell recovery was faster in the unmanipulated group only within the first month. However, this delay could be compensated by transplantation of >5.385 × 106 CD34+ cells/kg. Especially for patients receiving immunotherapy after HDC large numbers of immune effector cells such as NK and T cells are necessary to mediate antibody-dependent cellular cytotoxicity. Therefore, in patients receiving autologous CD34+-selected grafts, our data emphasize the need to administer high stem cell counts.

Current vaccination status and safety of children with peripheral neuroblastoma in the real-world

Background

peripheral neuroblastic tumors (pNT) have high incidence and mortality, and infants are prone to various infectious diseases. The purpose of this study is to understand the immunization status of children with pNT in the real-world and the incidence of adverse reactions after vaccination, and to evaluate the feasibility of vaccination and the influencing factors of vaccination.

Methods

Children with pNT treated in the Children's Hospital Affiliated to Zhejiang University from January 1, 2011 to December 1, 2021 were included. By referring to medical records, the vaccination history of the national immunization program (NIP) vaccines and the occurrence of adverse events following immunization(AEFI), current status and safety of immunization in children with pNT in the real-world were analyzed.

Results

Among 784 children with pNT, 394 were able to obtain the history of vaccination. The overall vaccination rate of NIP vaccines was 71.49% before chemotherapy and 37.67% after chemotherapy, and the recovery time of vaccination after treatment was 16.00 (6.00,24.00) months. Age, time of tumor diagnosis and disease classification were significantly correlated with vaccination. AEFI reported an incidence of 0.23‰.

Conclusion

The vaccination rate of children with pNT is generally low, especially the vaccination rate after chemotherapy. The vaccination safety is good, children should be encouraged to immunize.

Anti-GD2 Antibody Dinutuximab Beta and Low-Dose Interleukin 2 After Haploidentical Stem-Cell Transplantation in Patients With Relapsed Neuroblastoma: A Multicenter, Phase I/II Trial

PURPOSE

Patients with relapsed high-risk neuroblastoma (rHR-NB) have a poor prognosis. We hypothesized that graft-versus-neuroblastoma effects could be elicited by transplantation of haploidentical stem cells (haplo-SCT) exploiting cytotoxic functions of natural killer cells and their activation by the anti-GD2 antibody dinutuximab beta (DB). This phase I/II trial assessed safety, feasibility, and outcomes of immunotherapy with DB plus subcutaneous interleukin-2 (scIL2) after haplo-SCT in patients with rHR-NB.

METHODS

Patients age 1-21 years underwent T-/B-cell-depleted haplo-SCT followed by DB and scIL2. The primary end point 'success of treatment' encompassed patients receiving six cycles, being alive 180 days after end of trial treatment without progressive disease, unacceptable toxicity, acute graft-versus-host-disease (GvHD) ≥grade 3, or extensive chronic GvHD.

RESULTS

Seventy patients were screened, and 68 were eligible for immunotherapy. Median number of DB cycles was 6 (range, 1-9). Median number of scIL2 cycles was 3 (1-6). The primary end point was met by 37 patients (54.4%). Median observation time was 7.8 years. Five-year event-free survival (EFS) and overall survival from start of trial treatment were 43% (95% CI, 31 to 55) and 53% (95% CI, 41 to 65), respectively. Five-year EFS among patients in complete remission (CR; 52%; 95% CI, 31 to 69) or partial remission (44%; 95% CI, 27 to 60) before immunotherapy were significantly better compared with patients with nonresponse/mixed response/progressive disease (13%; 95% CI, 1 to 42; P = .026). Overall response rate in 43 patients with evidence of disease after haplo-SCT was 51% (22 patients), with 15 achieving CR (35%). Two patients developed GvHD grade 2 and 3 each. No unexpected adverse events occurred.

CONCLUSION

DB therapy after haplo-SCT in patients with rHR-NB is feasible, with low risk of inducing GvHD, and results in long-term remissions likely attributable to increased antineuroblastoma activity by donor-derived effector cells.

Outcomes Following GD2-Directed Postconsolidation Therapy for Neuroblastoma After Cessation of Random Assignment on ANBL0032: A Report From the Children's Oncology Group

PURPOSE

Postconsolidation immunotherapy including dinutuximab, granulocyte-macrophage colony-stimulating factor, and interleukin-2 improved outcomes for patients with high-risk neuroblastoma enrolled on the randomized portion of Children's Oncology Group study ANBL0032. After random assignment ended, all patients were assigned to immunotherapy. Survival and toxicities were assessed.

PATIENTS AND METHODS

Patients with a pre-autologous stem cell transplant (ASCT) response (excluding bone marrow) of partial response or better were eligible. Demographics, stage, tumor biology, pre-ASCT response, and adverse events were summarized using descriptive statistics. Event-free survival (EFS) and overall survival (OS) from time of enrollment (up to day +200 from last ASCT) were evaluated.

RESULTS

From 2009 to 2015, 1,183 patients were treated. Five-year EFS and OS for the entire cohort were 61.1 ± 1.9% and 71.9 ± 1.7%, respectively. For patients ≥ 18 months old at diagnosis with International Neuroblastoma Staging System stage 4 disease (n = 662) 5-year EFS and OS were 57.0 ± 2.4% and 70.9 ± 2.2%, respectively. EFS was superior for patients with complete response/very good partial response pre-ASCT compared with those with PR (5-year EFS: 64.2 ± 2.2% v 55.4 ± 3.2%, P = .0133); however, OS was not significantly different. Allergic reactions, capillary leak, fever, and hypotension were more frequent during interleukin-2-containing cycles than granulocyte-macrophage colony-stimulating factor-containing cycles (P < .0001). EFS was superior in patients with higher peak dinutuximab levels during cycle 1 (P = .034) and those with a high affinity FCGR3A genotype (P = .0418). Human antichimeric antibody status did not correlate with survival.

CONCLUSION

Analysis of a cohort assigned to immunotherapy after cessation of random assignment on ANBL0032 confirmed previously described survival and toxicity outcomes. EFS was highest among patients with end-induction complete response/very good partial response. Among patients with available data, higher dinutuximab levels and FCGR3A genotype were associated with superior EFS. These may be predictive biomarkers for dinutuximab therapy.

Heightened metabolic responses in NK cells from patients with neuroblastoma suggests increased potential for immunotherapy

High risk neuroblastoma is responsible for 15% of deaths in pediatric cancer patients. The introduction of anti-GD2 immunotherapy has significantly improved outcomes but there is still only approximately a 50% 5 year event-free-survival for these children and improvements in treatments are urgently required. Anti-GD2 immunotherapy uses the patients’ own immune system to kill cancer cells. In particular, Natural Killer (NK) cells kill antibody coated tumor cells by a process called antibody dependent cellular cytotoxicity (ADCC). However, our previous work has highlighted metabolic exhaustion of NK cells in circulating blood of adult cancer patients, identifying this as a potential therapeutic target. In this study, we investigated circulating NK cells in patients newly diagnosed with neuroblastoma. We found evidence of activation of NK cells in vivo by the cancer itself. While some evidence of NK cell dysfunction was observed in terms of IFNγ production, most results indicated that the NK cell compartment remained relatively intact. In fact, some aspects of metabolic and functional activities were actually increased in patients compared to controls. Glycolytic responses, which we show are crucial for ADCC, were actually enhanced in patients and CD16, the NK cell receptor that mediates ADCC, was also expressed at high levels in some patients. Overall, the data suggest that patient NK cells could be harvested at diagnosis for subsequent beneficial autologous use during immunotherapy. Enhancing glycolytic capacity of cell therapies could also be a strategic goal of future cell therapies for patients with neuroblastoma and indeed other cancers.

Strategies for Potentiating NK-Mediated Neuroblastoma Surveillance in Autologous or HLA-Haploidentical Hematopoietic Stem Cell Transplants

Simple Summary

High-risk neuroblastomas (HR-NB) are malignant tumors of childhood that are treated with a very aggressive and life-threatening approach; this includes autologous hemopoietic stem cell transplantation (HSCT) and the infusion of a mAb targeting the GD2 tumor-associated antigen. Although the current treatment provided benefits, the 5-year overall survival remains below 50% due to relapses and refractoriness to therapy. Thus, there is an urgent need to ameliorate the standard therapeutic protocol, particularly improving the immune-mediated anti-tumor responses. Our review aims at summarizing and critically discussing novel immunotherapeutic strategies in HR-NB, including NK cell-based therapies and HLA-haploidentical HSCT from patients’ family.

Abstract

High-risk neuroblastomas (HR-NB) still have an unacceptable 5-year overall survival despite the aggressive therapy. This includes standardized immunotherapy combining autologous hemopoietic stem cell transplantation (HSCT) and the anti-GD2 mAb. The treatment did not significantly change for more than one decade, apart from the abandonment of IL-2, which demonstrated unacceptable toxicity. Of note, immunotherapy is a promising therapeutic option in cancer and could be optimized by several strategies. These include the HLA-haploidentical αβT/B-depleted HSCT, and the antibody targeting of novel NB-associated antigens such as B7-H3, and PD1. Other approaches could limit the immunoregulatory role of tumor-derived exosomes and potentiate the low antibody-dependent cell cytotoxicity of CD16 dim/neg NK cells, abundant in the early phase post-transplant. The latter effect could be obtained using multi-specific tools engaging activating NK receptors and tumor antigens, and possibly holding immunostimulatory cytokines in their construct. Finally, treatments also consider the infusion of novel engineered cytokines with scarce side effects, and cell effectors engineered with chimeric antigen receptors (CARs). Our review aims to discuss several promising strategies that could be successfully exploited to potentiate the NK-mediated surveillance of neuroblastoma, particularly in the HSCT setting. Many of these approaches are safe, feasible, and effective at pre-clinical and clinical levels.

Anti-GD2 IgA kills tumors by neutrophils without antibody-associated pain in the preclinical treatment of high-risk neuroblastoma

Background

The addition of monoclonal antibody therapy against GD2 to the treatment of high-risk neuroblastoma led to improved responses in patients. Nevertheless, administration of GD2 antibodies against neuroblastoma is associated with therapy-limiting neuropathic pain. This severe pain is evoked at least partially through complement activation on GD2-expressing sensory neurons.

Methods

To reduce pain while maintaining antitumor activity, we have reformatted the approved GD2 antibody ch14.18 into the IgA1 isotype. This novel reformatted IgA is unable to activate the complement system but efficiently activates leukocytes through the FcαRI (CD89).

Results

IgA GD2 did not activate the complement system in vitro nor induced pain in mice. Importantly, neutrophil-mediated killing of neuroblastoma cells is enhanced with IgA in comparison to IgG, resulting in efficient tumoricidal capacity of the antibody in vitro and in vivo.

Conclusions

Our results indicate that employing IgA GD2 as a novel isotype has two major benefits: it halts antibody-induced excruciating pain and improves neutrophil-mediated lysis of neuroblastoma. Thus, we postulate that patients with high-risk neuroblastoma would strongly benefit from IgA GD2 therapy.

Immune Monitoring during Therapy Reveals Activitory and Regulatory Immune Responses in High-Risk Neuroblastoma

Simple Summary

Neuroblastoma is a type of childhood cancer accounting for approximately 15% of childhood cancer deaths. Despite intensive treatment, including immunotherapy, prognosis of high-risk neuroblastoma is poor. Increasing amounts of research show that the fighting capacity of the immune system is very important for the outcome of neuroblastoma patients. Therefore, we investigated the fighting capacity of immune cells in blood at diagnosis and during the different phases of therapy. In this study, we observed both processes that stimulate and processes that decrease fighting capacity of immune cells in neuroblastoma patients during therapy. Despite this, we show that overall fighting capacity of the immune system of neuroblastoma patients is impaired at diagnosis as well as during therapy. In addition, we observed a lot of variation between patients, which might explain differences in therapy efficacy between patients. This study provides insight for improvement of therapy timing as well as new therapy strategies enhancing immune cell fighting capacity.

Abstract

Despite intensive treatment, including consolidation immunotherapy (IT), prognosis of high-risk neuroblastoma (HR-NBL) is poor. Immune status of patients over the course of treatment, and thus immunological features potentially explaining therapy efficacy, are largely unknown. In this study, the dynamics of immune cell subsets and their function were explored in 25 HR-NBL patients at diagnosis, during induction chemotherapy, before high-dose chemotherapy, and during IT. The dynamics of immune cells varied largely between patients. IL-2- and GM-CSF-containing IT cycles resulted in significant expansion of effector cells (NK-cells in IL-2 cycles, neutrophils and monocytes in GM-CSF cycles). Nonetheless, the cytotoxic phenotype of NK-cells was majorly disturbed at the start of IT, and both IL-2 and GM-CSF IT cycles induced preferential expansion of suppressive regulatory T-cells. Interestingly, proliferative capacity of purified patient T-cells was impaired at diagnosis as well as during therapy. This study indicates the presence of both immune-enhancing as well as regulatory responses in HR-NBL patients during (immuno)therapy. Especially the double-edged effects observed in IL-2-containing IT cycles are interesting, as this potentially explains the absence of clinical benefit of IL-2 addition to IT cycles. This suggests that there is a need to combine anti-GD2 with more specific immune-enhancing strategies to improve IT outcome in HR-NBL.

Monitoring Immune Responses in Neuroblastoma Patients during Therapy

Neuroblastoma (NBL) is the most common extracranial solid tumor in childhood. Despite intense treatment, children with this high-risk disease have a poor prognosis. Immunotherapy showed a significant improvement in event-free survival in high-risk NBL patients receiving chimeric anti-GD2 in combination with cytokines and isotretinoin after myeloablative consolidation therapy. However, response to immunotherapy varies widely, and often therapy is stopped due to severe toxicities. Objective markers that help to predict which patients will respond or develop toxicity to a certain treatment are lacking. Immunotherapy guided via immune monitoring protocols will help to identify responders as early as possible, to decipher the immune response at play, and to adjust or develop new treatment strategies. In this review, we summarize recent studies investigating frequency and phenotype of immune cells in NBL patients prior and during current treatment protocols and highlight how these findings are related to clinical outcome. In addition, we discuss potential targets to improve immunogenicity and strategies that may help to improve therapy efficacy. We conclude that immune monitoring during therapy of NBL patients is essential to identify predictive biomarkers to guide patients towards effective treatment, with limited toxicities and optimal quality of life.