Adoptive Cell Therapy in Treating Pediatric Solid Tumors

Ex vivo-expanded and activated haploidentical natural killer cells infusion before autologous stem cell transplantation in high-risk neuroblastoma: a phase I/II pilot study

Given that natural killer (NK; CD3 - CD56 +) cells-mediated antibody-dependent cell cytotoxicity (ADCC) plays an important role in targeting neuroblastoma (NB) cells, adoptive cell therapy (ACT) utilizing expanded and activated haploidentical NK cells has emerged as a promising immunotherapeutic approach in pediatric patients with high-risk NB. In this pilot study, five pediatric patients with high-risk NB were enrolled. After harvesting hematopoietic progenitor cells (HPCs), patients received an intravenous infusion of high-activity iodine-131 (131I)-meta-iodobenzylguanidine (131I-MIBG). Seven days after the 131I-MIBG infusion and before the delivery of a single infusion of haploidentical purified NK cells, patients were administered a preparative regimen to establish a lymphodepleted host environment conducive to improved donor NK cell survival. Four days after the NK cell infusion, patients underwent the conditioning regimen, then received autologous hematopoietic stem cell transplantation (AHSCT). All patients achieved successful neutrophil and platelet engraftment. No adverse reactions were noted during or after the infusion of NK cells. Our study shows that incorporating NK cell infusion before AHSCT as a component of the conditioning regimen for consolidative therapy in pediatric patients with high-risk NB can be safe and well tolerated. IRCT Registration Number: IRCT20140818018842N32.

Expansion of tumor-infiltrating and marrow-infiltrating lymphocytes from pediatric malignant solid tumors

INTRODUCTION

The expansion of tumor-infiltrating lymphocytes (TIL) for adoptive cellular therapy is under investigation in many solid tumors of adulthood. Marrow-infiltrating lymphocytes (MIL) have demonstrated antitumor reactivity preclinically. Successful expansion of TIL/MIL has not been reported across pediatric solid tumor histologies. The objective of this study was to demonstrate successful expansion of TIL from pediatric solid tumors for translation in an adoptive cell therapy (ACT) treatment strategy.

METHODS

A prospective study of TIL/MIL expansion was performed on solid tumors of pediatric patients undergoing standard-of-care procedures. TIL/MIL expansions were performed in the presence of high-dose interleukin 2. To demonstrate a full-scale expansion to clinically-relevant cell doses for TIL therapy, initial TIL culture was followed by a rapid expansion protocol for select patients. Expanded specimens were analyzed for phenotype by flow cytometry and for anti-tumor reactivity by the interferon-gamma release assay.

RESULTS

Eighteen tumor samples were obtained. Initial TIL cultures were successfully generated from 14/18 samples (77.7%). A median of 5.52 × 107 (range: 2.5 × 106-3.23 × 108) cells were produced from initial cultures, with 46.9% expressing a CD3 phenotype (46.9%). Eight samples underwent rapid expansion, demonstrating a median 458-fold expansion and a CD3 phenotype of 98%. Initial MIL cultures were successfully generated from five samples, with a predominantly CD3 phenotype (45.2%). Sufficient tumor tissue was only available for seven TIL samples to be tested for reactivity; none demonstrated responsiveness to autologous tumor.

CONCLUSIONS

TIL and MIL expansion from pediatric solid tumors was successful, including the full-scale expansion process. This data supports translation to an ACT-TIL treatment strategy in the pediatric population and thus a Phase I trial of ACT-TIL in pediatric high-risk solid tumors is planned.

Engineering the next generation of cell-based therapeutics

Cell-based therapeutics are an emerging modality with the potential to treat many currently intractable diseases through uniquely powerful modes of action. Despite notable recent clinical and commercial successes, cell-based therapies continue to face numerous challenges that limit their widespread translation and commercialization, including identification of the appropriate cell source, generation of a sufficiently viable, potent and safe product that meets patient- and disease-specific needs, and the development of scalable manufacturing processes. These hurdles are being addressed through the use of cutting-edge basic research driven by next-generation engineering approaches, including genome and epigenome editing, synthetic biology and the use of biomaterials.

Adoptive Cellular Therapy for Pediatric Solid Tumors: Beyond Chimeric Antigen Receptor-T Cell Therapy

ABSTRACT

Children and adolescents with high-risk (metastatic and relapsed) solid tumors have poor outcomes despite intensive multimodal therapy, and there is a pressing need for novel therapeutic strategies. Adoptive cellular therapy (ACT) has demonstrated activity in multiple adult cancer types, and opportunity exists to expand the use of this therapy in children. Employment of immunotherapy in the pediatric population has realized only modest overall clinical trial results, with success thus far restricted mainly to antibody-based therapies and chimeric antigen receptor T-cell therapies for lymphoid malignancy. As we improve our understanding of the orchestrated cellular and molecular mechanisms involved in ACT, this will provide biologic insight and improved ACT strategies for pediatric malignancies. This review focuses on ACT strategies outside of chimeric antigen receptor T-cell therapy, including completed and ongoing clinical trials, and highlights promising preclinical data in tumor-infiltrating lymphocytes that enhance the clinical efficacy of ACT for high-risk pediatric solid tumors.

Liquid Biopsy as a Prognostic and Theranostic Tool for the Management of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinomas (PDAC) represent one of the deadliest cancers worldwide. Survival is still low due to diagnosis at an advanced stage and resistance to treatment. Herein, we review the main types of liquid biopsy able to help in both prognosis and adaptation of treatments.

Chimeric Antigen Receptor T cell Therapy and the Immunosuppressive Tumor Microenvironment in Pediatric Sarcoma

Simple Summary

This review explores the current trials using cellular immunotherapies in pediatric sarcoma and describes examples of promising new CAR T targets in sarcoma that are in preclinical development. We provide insights into the ways in which the immunosuppressive tumor immune microenvironment can impact on CAR T cell therapy, highlighting specific mechanisms by which the tumor microenvironment may limit CAR T efficacy. Appreciation of these mechanisms may lead to rational combinations of immunotherapies, for example, the combination of CAR T cells with checkpoint inhibitor drugs. We also describe innovations in CAR T cell generation and combination therapies that may pave the way to better clinical outcomes for these patients.

Abstract

Sarcomas are a diverse group of bone and soft tissue tumors that account for over 10% of childhood cancers. Outcomes are particularly poor for children with refractory, relapsed, or metastatic disease. Chimeric antigen receptor T (CAR T) cells are an exciting form of adoptive cell therapy that potentially offers new hope for these children. In early trials, promising outcomes have been achieved in some pediatric patients with sarcoma. However, many children do not derive benefit despite significant expression of the targeted tumor antigen. The success of CAR T cell therapy in sarcomas and other solid tumors is limited by the immunosuppressive tumor microenvironment (TME). In this review, we provide an update of the CAR T cell therapies that are currently being tested in pediatric sarcoma clinical trials, including those targeting tumors that express HER2, NY-ESO, GD2, EGFR, GPC3, B7-H3, and MAGE-A4. We also outline promising new CAR T cells that are in pre-clinical development. Finally, we discuss strategies that are being used to overcome tumor-mediated immunosuppression in solid tumors; these strategies have the potential to improve clinical outcomes of CAR T cell therapy for children with sarcoma.

Innate Immune Regulation Under Magnetic Fields With Possible Mechanisms and Therapeutic Applications

With the wide applications of magnetic fields (MFs) in medicine, researchers from different disciplines have gained interest in understanding the effect of various types of MFs on living cells and organisms. In this paper, we mainly focus on the immunological and physical aspects of the immune responses and their mechanisms under different types of MFs. Immune cells were slightly affected by low-frequency alternating MFs but were strongly influenced by moderate-intensity MFs and high-gradient MFs (HGMFs). Larger immune cells, such as macrophages, were more sensitive to HGMFs, which biased the cell polarization into the anti-inflammatory M2 phenotype. Subject to the gradient forces of varying directions and strength, the elongated M2 macrophage also remodeled the cytoskeleton with actin polymerization and changed the membrane receptors and ion channel gating. These alterations were very similar to changes caused by the small GTPase RhoA interference in macrophage. Regulation of iron metabolism may also contribute to the MF effects in macrophages. High MFs were found to regulate the iron content in monocyte-/macrophage-derived osteoclasts by affecting the expression of iron-regulation genes. On the other hand, paramagnetic nanoparticles (NPs) combined with external MFs play an important role in T-cell immunity. Paramagnetic NP-coated T-cells can cluster their T-cell receptors (TCRs) by using an external MF, thus increasing the cell–cell contact and communication followed by enhanced tumor killing capacity. The external MF can also guide the adoptively transferred magnetic NP-coated T-cells to their target sites in vivo, thus dramatically increasing the efficiency of cell therapy. Additionally, iron oxide NPs for ferroptosis-based cancer therapy and other MF-related therapeutic applications with obstacles were also addressed. Furthermore, for a profound understanding of the effect of MFs on immune cells, multidisciplinary research involving both experimental research and theoretical modeling is essential.

Advances in the Management of Pediatric Sarcomas

PURPOSE OF REVIEW

The prognosis of pediatric patients who present with metastatic or recurrent sarcomas remains poor. In this review, we summarize the advances in the management of metastatic and relapsed pediatric sarcoma by highlighting recent and future clinical trials.

RECENT FINDINGS

Research into the identification of novel therapies for refractory pediatric sarcomas continues to advance. Outcomes have not improved in several decades underlying a need for improved understanding of the biology behind these tumors and the identification of novel therapeutic molecular targets that can be exploited pharmacologically. Multiple challenges remain for novel therapy in sarcomas such as the selection of effective targets, management of toxicities, and the tumor microenvironment. Many unique challenges remain in the treatment of patients with refractory pediatric sarcomas. Multiple strategies and targets are under investigation that hold promise.

Emerging vistas in CAR T-cell therapy: challenges and opportunities in solid tumors

INTRODUCTION

Despite advances in modern evidence-based medicine, cancer remains a major cause of global disease-associated mortality. CAR T-cell therapy is a major histocompatibility complex (MHC)-independent immunotherapy involving adoptive cell transfer. Cancer immunotherapy witnessed a major breakthrough with the US FDA approval of the first chimeric antigen receptor (CAR) T-cell therapy Kymriah^TM (tisagenlecleucel) for relapsed or refractory (R/R) acute lymphoblastic leukemia (ALL) in August 2017 followed by approval of Yescarta® (axicabtagene ciloleucel) for R/R non-Hodgkin's lymphoma (NHL) in October 2017.

AREAS COVERED

We review the potential of CAR T-cell therapy which, despite showing great promise in hematological malignancies, faces significant challenges in targeting solid tumors. We address these challenges and discuss proposed strategies to overcome them in solid tumors. We highlight the potential of CAR T-cell therapy as cancer precision medicine and briefly discuss the 'financial toxicity' of CAR T-cell therapy.

EXPERT OPINION

Taken together, we discuss various strategies to circumvent the limitations of CAR T-cell therapy in solid tumors. Despite the rapid advances in CAR NK-cell therapies, there is immense scope for CAR T-cell therapy in solid tumors. We provide a synthetic review of CAR T-cell therapy that will drive future research and harness its full potential in cancer precision medicine for solid tumors.

The Possibilities of Immunotherapy for Children with Primary Immunodeficiencies Associated with Cancers

Many primary immunodeficiencies (PIDs) are recognised as being associated with malignancies, particularly lymphoid malignancies, which represent the highest proportion of cancers occurring in conjunction with this underlying condition. When patients present with genetic errors of immunity, clinicians must often reflect on whether to manage antitumoral treatment conventionally or to take a more personalised approach, considering possible existing comorbidities and the underlying status of immunodeficiency. Recent advances in antitumoral immunotherapies, such as monoclonal antibodies, antigen-specific adoptive cell therapies or compounds with targeted effects, potentially offer significant opportunities for optimising treatment for those patients, especially with lymphoid malignancies. In cases involving PIDs, variable oncogenic mechanisms exist, and opportunities for antitumoral immunotherapies can be considered accordingly. In cases involving a DNA repair defect or genetic instability, monoclonal antibodies can be proposed instead of chemotherapy to avoid severe toxicity. Malignancies secondary to uncontrolled virus-driven proliferation or the loss of antitumoral immunosurveillance may benefit from antivirus cell therapies or allogeneic stem cell transplantation in order to restore the immune antitumoral caretaker function. A subset of PIDs is caused by gene defects affecting targetable signalling pathways directly involved in the oncogenic process, such as the constitutive activation of phosphoinositol 3-kinase/protein kinase B (PI3K/AKT) in activated phosphoinositide 3-kinase delta syndrome (APDS), which can be settled with PI3K/AKT inhibitors. Therefore, immunotherapy provides clinicians with interesting antitumoral therapeutic weapons to treat malignancies when there is an underlying PID.

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.

Cytokine-induced killer cells/natural killer cells combined with anti-GD2 monoclonal antibody increase cell death rate in neuroblastoma SK-N-SH cells

Neuroblastoma (NB) is one of the most common extracranial, solid, pediatric malignancies. Despite improvements in conventional therapies, including surgery, chemotherapy and radiation therapy, the prognosis of stage IV NB remains poor, indicating that novel treatment strategies are required. Immunotherapies, such as anti-GD2 monoclonal antibodies, used alone or in combination with cytokines, and peripheral blood mononuclear cells or cord blood mononuclear cells (CBMNCs), have been indicated to cause NB cell death and to prolong patient survival in high-risk NB; however, they remain limited by severe cytotoxicity and side effects. In the present study, it was determined that anti-GD2 monoclonal antibody alone or CBMNC-isolated cytokine-induced killer (CIK)/natural killer (NK) cells alone significantly induced cell death of NB SK-N-SH cells, and the combination of anti-GD2 antibody and CIK/NK cells could significantly increase the cell death rate compared with either treatment alone. In addition, based on a method referred to our previous study, it was identified that a two-cytokine culture system, using interleukin IL-2 and IL-7, effectively stimulated the proliferation of CIK/NK cells. These results serve to suggest a novel treatment strategy for relapsed/refractory NB with high efficiency and few side effects.

Therapeutic Opportunities in Neuroblastoma Using Nanotechnology

Neuroblastoma (NB) is the most common extracranial solid tumor preferentially occurring in preschoolers. Its characteristic aggressiveness and heterogeneous clinical behavior are especially visible in relapsed or refractory cases and hamper therapeutic success. Although the introduction of novel antitumor agents, such as dinutuximab, isotretinoin, irinotecan, or I-131- metaiodobenzylguanidine, has increased survival rates, the situation in high-risk NB remains dismal. Moreover, treatment is particularly aggressive in these patients, leading to short- and long-term toxicities. The extensive research performed using nanotechnology in recent decades has prompted its application as a therapeutic alternative to overcome some of the common limitations of conventional chemotherapy. Nevertheless, the therapeutic role of nanomedicine in pediatric tumors like NB is not fully elucidated, and to date, only albumin-bound paclitaxel nanoparticles have reached clinic stages. In this review, we summarize the current therapeutic strategies for NB with special attention to the use of nanomedicine. We also highlight the preclinical studies on passive and active targeting nanodelivery of therapeutics in experimental NB models.