Incorporation of high-dose 131 I-metaiodobenzylguanidine treatment into killer immunoglobulin-like receptor/HLA-ligand mismatched haploidentical stem cell transplantation for children with neuroblastoma who failed tandem autologous stem cell transplantation

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.

KSNM60 in Non-thyroidal Radionuclide Therapy: Leaping into the Future

This year, the Korean Society of Nuclear Medicine (KSNM) is celebrating its 60th anniversary. Treatment, as well as diagnosis, has played a very important role in the development of nuclear medicine. Since I-131 was used for thyroid therapy in 1959, other radionuclide therapy is still being used, and attempts to use new radionuclide are increasing. In this review, we briefly summarize and introduce the therapies such as radioimmunotherapy, transarterial radioembolization, radionuclide therapy for neuroendocrine tumors, peptide receptor radionuclide therapy, control of metastatic bone pain, radiation synovectomy, radionuclide brachytherapy, alpha particle therapy, and boron neutron capture therapy, which has been being attempted so far in the field of nuclear medicine.

Safety and immune cell kinetics after donor natural killer cell infusion following haploidentical stem cell transplantation in children with recurrent neuroblastoma

INTRODUCTION

Under the hypothesis that early natural killer cell infusion (NKI) following haploidentical stem cell transplantation (haplo-SCT) will reduce relapse in the early post-transplant period, we conducted a pilot study to evaluate the safety and feasibility of NKI following haplo-SCT in children with recurrent neuroblastoma who failed previous tandem high-dose chemotherapy and autologous SCT.

METHODS

We used the high-dose 131I-metaiodobenzylguanidine and cyclophosphamide/fludarabine/anti-thymocyte globulin regimen for conditioning and infused 3 × 107/kg of ex-vivo expanded NK cells derived from a haploidentical parent donor on days 2, 9, and 16 post-transplant. Interleukin-2 was administered (1 × 106 IU/m2/day) subcutaneously to activate infused donor NK cells on days 2, 4, 6, 9, 11, 13, 16, 18, and 20 post-transplant.

RESULTS

Seven children received a total of 19 NKIs, and NKI-related acute toxicities were fever (n = 4) followed by chills (n = 3) and hypertension (n = 3); all toxicities were tolerable. Grade ≥II acute GVHD and chronic GVHD developed in two and five patients, respectively. Higher amount of NK cell population was detected in peripheral blood until 60 days post-transplant than that in the reference cohort. Cytomegalovirus and BK virus reactivation occurred in all patients and Epstein-Barr virus in six patients. Six patients died of relapse/progression (n = 5) or treatment-related mortality (n = 1), and one patient remained alive.

CONCLUSION

NKI following haplo-SCT was relatively safe and feasible in patients with recurrent neuroblastoma. Further studies to enhance the graft-versus-tumor effect without increasing GVHD are needed.

Treatment Outcomes in Children and Adolescents with Relapsed or Progressed Solid Tumors: a 20-year, Single-Center Study

BACKGROUND

By estimating the survival rates and exploring prognostic factors in pediatric patients with relapsed or progressed solid tumors, our purpose was to generate background data for future studies.

METHODS

We reviewed the medical records of 258 patients with solid tumors who experienced relapse/progression and received subsequent salvage treatment between 1996 and 2016.

RESULTS

A total of 60 patients remained progression-free during first-line salvage treatment, while the remaining 198 patients experienced relapse/progression again; 149 underwent second-line salvage treatment. A total of 76 patients underwent high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT), and 44 patients received allogeneic SCT. The 10-year progression-free survival (PFS) and overall survival (OS) from relapse/progression were 18.4% ± 2.7% and 24.5% ± 3.0%, respectively. Survival rates were relatively higher in patients with anaplastic ependymoma, initially non-high-risk neuroblastoma, osteosarcoma, Wilms tumor and retinoblastoma. A multivariate analysis showed that relapse/progression during initial treatment, metastatic relapse/progression, and impossible debulking surgery were independent poor prognostic factors for both PFS and OS. Patients who exhibited a complete response or partial response during conventional salvage treatment showed significantly higher survival after SCT than those with stable disease or progressive disease (10-year OS: 54.8% ± 7.0% vs. 7.0% ± 3.5%, P < 0.001).

CONCLUSION

The prognosis of relapsed/progressed pediatric solid tumors still remains unsatisfactory. New, effective treatment strategies are needed to overcome limitations of current approaches. Hopefully, the background data generated herein will be used in future clinical trials involving patients with relapsed/progressed solid tumors.

Feasibility of High-dose Iodine-131-metaiodobenzylguanidine Therapy for High-risk Neuroblastoma Preceding Myeloablative Chemotherapy and Hematopoietic Stem Cell Transplantation: a Study Protocol

Objective(s):

High-risk neuroblastoma is a childhood cancer with poor prognosis despite modern multimodality therapy. Internal radiotherapy using ¹³¹I-metaiodobenzylguanidine (MIBG) is effective for treating the disease even if it is resistant to chemotherapy. The aim of this study is to evaluate the safety and efficacy of ¹³¹I-MIBG radiotherapy combined with myeloablative high-dose chemotherapy and hematopoietic stem cell transplantation.

Methods:

Patients with high-risk neuroblastoma will be enrolled in this study. A total of 8 patients will be registered. Patients will receive 666 MBq/kg of ¹³¹I-MIBG and after safety evaluation will undergo high-dose chemotherapy and hematopoietic stem cell transplantation. Autologous and allogeneic stem cell sources will be accepted. After engraftment or 28 days after hematopoietic stem cell transplantation, the safety and response will be evaluated.

Conclusion:

This is the first prospective study of ¹³¹I-MIBG with high-dose chemotherapy and hematopoietic stem cell transplantation in Japan. The results will be the basis of a future nationwide clinical trial.

Selective T cell-depleted haploidentical hematopoietic stem cell transplantation for relapsed/refractory neuroblastoma

Relapsed/refractory NB carries a bleak outcome, warranting novel treatment options. HaploHSCT induces a graft-versus-NB effect via natural killer cell alloreactivity. Review of patients with relapsed/refractory NB who underwent haploHSCT with ex vivo T-cell depletion in our unit from 2013 through 2018. Ten patients were identified (male=5; median age at haploHSCT=6.45 y, range: 3.49-11.02 y). Indications were relapsed in 7 and refractoriness in 3; disease status at haploHSCT was CR in 2, PR in 6, and PD in 2. All patients received peripheral blood stem cell grafts after ex vivo T-cell depletion (CD3/CD19-depletion=1; TCR-αβ/CD19-depletion=4; CD3/CD45RA-depletion=4; and TCR-αβ/CD45RA-depletion=1). Conditioning regimens were fludarabine-based. Neutrophils engrafted on median D + 10 (range: D + 9 to +13), and platelets engrafted (≥20 × 109 /L) on median D + 8 (range: D + 5 to D + 14). Early T- and NK-cell recovery were evident. Of the 10 patients, acute rejection developed in 1 (who died of PD despite rescue HSCT), and 1 died of sepsis before engraftment; 8 experienced full donor-chimerism post-HSCT. Among the 8, 6 experienced CR, 1 died of PD, and 1 died of pulmonary hypertensive crisis before evaluation. At publication, 4 were in remission (2.8, 7.4, 28.5, and 58.9 months). No significant GvHD occurred. HaploHSCT with selective ex vivo T-cell depletion may be a safe and useful salvage strategy for relapsed/refractory NB.

Reduced-Intensity Haploidentical Bone Marrow Transplantation with Post-Transplant Cyclophosphamide for Solid Tumors in Pediatric and Young Adult Patients

High-risk, recurrent, or refractory solid tumors in pediatric, adolescent, and young adult (AYA) patients have an extremely poor prognosis despite current intensive treatment regimens. We piloted an allogeneic bone marrow transplant platform using reduced-intensity conditioning (RIC) and partially HLA-mismatched (haploidentical) related donors for this population of pediatric and AYA solid tumor patients. Sixteen patients received fludarabine, cyclophosphamide, melphalan, and low-dose total body irradiation RIC haploidentical BMT (haploBMT) followed by post-transplantation cyclophosphamide (PTCy), mycophenolate mofetil, and sirolimus. All assessable patients were full donor chimeras on day 30 with a median neutrophil recovery of 19 days and platelet recovery of 21 days. One patient (7%) exhibited secondary graft failure associated with concomitant infection. The median follow-up time was 15 months. Overall survival was 88%, 56%, and 21% at 6, 12, and 24 months, respectively. Median survival from transplant date was 14 months with a median progression-free survival 7 months. We observed limited graft-versus-host disease in 3 patients and nonrelapse mortality in 1 patient. We demonstrated that RIC haploBMT with PTCy is feasible and has acceptable toxicities in patients with incurable pediatric and AYA solid tumors; thus, this approach serves as a platform for post-transplant strategies to prevent relapse and optimize progression-free survival.