Taking T-Cell Oncotherapy Off-the-Shelf

Expanding the horizon of transient CAR T therapeutics using virus-free technology

The extraordinary success that chimeric antigen receptor (CAR) T cell therapies have shown over the years on fighting hematological malignancies is evidenced by the six FDA-approved products present on the market. CAR T treatments have forever changed the way we understand cellular immunotherapies, as current research in the topic is expanding even outside the field of cancer with very promising results. Until now, virus-based strategies have been used for CAR T cell manufacturing. However, this methodology presents relevant limitations that need to be addressed prior to wide spreading this technology to other pathologies and in order to optimize current cancer treatments. Several approaches are being explored to overcome these challenges such as virus-free alternatives that additionally offer the possibility of developing transient CAR expression or in vivo T cell modification. In this review, we aim to spotlight a pivotal juncture in the history of medicine where a significant change in perspective is occurring. We review the current progress made on viral-based CAR T therapies as well as their limitations and we discuss the future outlook of virus-free CAR T strategies to overcome current challenges and achieve affordable immunotherapies for a wide variety of pathologies, including cancer.

Lymphatic vessel: origin, heterogeneity, biological functions, and therapeutic targets

Lymphatic vessels, comprising the secondary circulatory system in human body, play a multifaceted role in maintaining homeostasis among various tissues and organs. They are tasked with a serious of responsibilities, including the regulation of lymph absorption and transport, the orchestration of immune surveillance and responses. Lymphatic vessel development undergoes a series of sophisticated regulatory signaling pathways governing heterogeneous-origin cell populations stepwise to assemble into the highly specialized lymphatic vessel networks. Lymphangiogenesis, as defined by new lymphatic vessels sprouting from preexisting lymphatic vessels/embryonic veins, is the main developmental mechanism underlying the formation and expansion of lymphatic vessel networks in an embryo. However, abnormal lymphangiogenesis could be observed in many pathological conditions and has a close relationship with the development and progression of various diseases. Mechanistic studies have revealed a set of lymphangiogenic factors and cascades that may serve as the potential targets for regulating abnormal lymphangiogenesis, to further modulate the progression of diseases. Actually, an increasing number of clinical trials have demonstrated the promising interventions and showed the feasibility of currently available treatments for future clinical translation. Targeting lymphangiogenic promoters or inhibitors not only directly regulates abnormal lymphangiogenesis, but improves the efficacy of diverse treatments. In conclusion, we present a comprehensive overview of lymphatic vessel development and physiological functions, and describe the critical involvement of abnormal lymphangiogenesis in multiple diseases. Moreover, we summarize the targeting therapeutic values of abnormal lymphangiogenesis, providing novel perspectives for treatment strategy of multiple human diseases.

CAR T cell therapy in multiple myeloma, where are we now and where are we heading for?

The introduction of chimeric antigen receptor (CAR) T cells revolutionized treatment of relapsed and refractory multiple myeloma (RRMM) in recent years. Currently, two CAR T cell products-idecabtagene vicleucel and ciltacabtagene autoleucel-are approved in the United States and the European Union to treat patients with three prior lines of therapy, including a proteasome inhibitor, an immunomodulatory drug, and an anti-CD38 antibody. Moreover, seminal phase III trials of both agents in earlier lines of therapy have been published recently. Despite unprecedented rates of deep and lasting remissions in RRMM, there are still areas of uncertainty regarding the optimal use and distribution of CAR T cells in multiple myeloma. In the current review, we discuss the available data on approved CAR T cell products as well as unmet clinical needs and ongoing developments to optimize usage of this promising treatment modality in multiple myeloma.

Genetically modified CD7-targeting allogeneic CAR-T cell therapy with enhanced efficacy for relapsed/refractory CD7-positive hematological malignancies: a phase I clinical study

Chimeric antigen receptor (CAR)-T cell therapy against T cell malignancies faces major challenges including fratricide between CAR-T cells and product contamination from the blasts. Allogeneic CAR-T cells, generated from healthy donor T cells, can provide ready-to-use, blast-free therapeutic products, but their application could be complicated by graft-versus-host disease (GvHD) and host rejection. Here we developed healthy donor-derived, CD7-targeting CAR-T cells (RD13-01) with genetic modifications to resist fratricide, GvHD and allogeneic rejection, as well as to potentiate antitumor function. A phase I clinical trial (NCT04538599) was conducted with twelve patients recruited (eleven with T cell leukemia/lymphoma, and one with CD7-expressing acute myeloid leukemia). All patients achieved pre-set end points and eleven proceeded to efficacy evaluation. No dose-limiting toxicity, GvHD, immune effector cell-associated neurotoxicity or severe cytokine release syndrome (grade ≥ 3) were observed. 28 days post infusion, 81.8% of patients (9/11) showed objective responses and the complete response rate was 63.6% (7/11, including the patient with AML). 3 of the responding patients were bridged to allogeneic hematopoietic stem cell transplantation. With a median follow-up of 10.5 months, 4 patients remained in complete remission. Cytomegalovirus (CMV) and/or Epstein-Barr virus (EBV) reactivation was observed in several patients, and one died from EBV-associated diffuse large B-cell lymphoma (DLBCL). Expansion of CD7-negative normal T cells was detected post infusion. In summary, we present the first report of a Phase I clinical trial using healthy donor-derived CD7-targeting allogeneic CAR-T cells to treat CD7+ hematological malignancies. Our results demonstrated the encouraging safety and efficacy profiles of the RD13-01 allogeneic CAR-T cells for CD7+ tumors.

Oncogenic transcription factors and neogenes: New opportunities for cancer immunotherapy?

Vibert et al. (2022) demonstrate that oncogenic transcription factor fusion proteins bind otherwise silent genomic regions, producing RNAs that can be spliced, exported, and translated. These "neogenes" represent possible targets for immunotherapy and may even be universal byproducts of altered transcription in cancer.

Targeting Immunosuppressive Tumor-Associated Macrophages Using Innate T Cells for Enhanced Antitumor Reactivity

The field of T cell-based and chimeric antigen receptor (CAR)-engineered T (CAR-T) cell-based antitumor immunotherapy has seen substantial developments in the past decade; however, considerable issues, such as graft-versus-host disease (GvHD) and tumor-associated immunosuppression, have proven to be substantial roadblocks to widespread adoption and implementation. Recent developments in innate immune cell-based CAR therapy have opened several doors for the expansion of this therapy, especially as it relates to allogeneic cell sources and solid tumor infiltration. This study establishes in vitro killing assays to examine the TAM-targeting efficacy of MAIT, iNKT, and γδT cells. This study also assesses the antitumor ability of CAR-engineered innate T cells, evaluating their potential adoption for clinical therapies. The in vitro trials presented in this study demonstrate the considerable TAM-killing abilities of all three innate T cell types, and confirm the enhanced antitumor abilities of CAR-engineered innate T cells. The tumor- and TAM-targeting capacity of these innate T cells suggest their potential for antitumor therapy that supplements cytotoxicity with remediation of tumor microenvironment (TME)-immunosuppression.

Antiviral Cell Products against COVID-19: Learning Lessons from Previous Research in Anti-Infective Cell-Based Agents

COVID-19 is a real challenge for the protective immunity. Some people do not respond to vaccination by acquiring an appropriate immunological memory. The risk groups for this particular infection such as the elderly and people with compromised immunity (cancer patients, pregnant women, etc.) have the most serious problems in developing an adequate immune response. Therefore, dendritic cell (DC) vaccines that are loaded ex vivo with SARS-CoV-2 antigens in the optimal conditions are promising for immunization. Lymphocyte effector cells with chimeric antigen receptor (CAR lymphocytes) are currently used mainly as anti-tumor treatment. Before 2020, few studies on the antiviral CAR lymphocytes were reported, but since the outbreak of SARS-CoV-2 the number of such studies has increased. The basis for CARs against SARS-CoV-2 were several virus-specific neutralizing monoclonal antibodies. We propose a similar, but basically novel and more universal approach. The extracellular domain of the immunoglobulin G receptors will be used as the CAR receptor domain. The specificity of the CAR will be determined by the antibodies, which it has bound. Therefore, such CAR lymphocytes are highly universal and have functional activity against any infectious agents that have protective antibodies binding to a foreign surface antigen on the infected cells.

Is It Possible to Separate the Graft-Versus-Leukemia (GVL) Effect Against B Cell Acute Lymphoblastic Leukemia From Graft-Versus-Host Disease (GVHD) After Hematopoietic Cell Transplant?

Hematopoietic cell transplant is a curative therapy for many pediatric patients with high risk acute lymphoblastic leukemia. Its therapeutic mechanism is primarily based on the generation of an alloreactive graft-versus-leukemia effect that can eliminate residual leukemia cells thus preventing relapse. However its efficacy is diminished by the concurrent emergence of harmful graft-versus-host disease disease which affects healthly tissue leading to significant morbidity and mortality. The purpose of this review is to describe the interventions that have been trialed in order to augment the beneficial graft-versus leukemia effect post-hematopoietic cell transplant while limiting the harmful consequences of graft-versus-host disease. This includes many emerging and promising strategies such as ex vivo and in vivo graft manipulation, targeted cell therapies, T-cell engagers and multiple pharmacologic interventions that stimulate specific donor effector cells.

Towards regulatory cellular therapies in solid organ transplantation

Organ transplantation is a modern medical success story. However, since its inception it has been limited by the need for pharmacological immunosuppression. Regulatory cellular therapies offer an attractive solution to these challenges by controlling transplant alloresponses through multiple parallel suppressive mechanisms. A number of cell types have seen an accelerated development into human trials and are now on the threshold of a long-awaited breakthrough in personalized transplant therapeutics. Here we assess recent developments with a focus on the most likely candidates, some of which have already facilitated successful immunosuppression withdrawal in early clinical trials. We propose that this may constitute a promising approach in clinical transplantation but also evaluate outstanding issues in the field, providing cause for cautious optimism.

Challenges and Prospects for Designer T and NK Cells in Glioblastoma Immunotherapy

Glioblastoma (GBM) is the most prevalent, aggressive primary brain tumour with a dismal prognosis. Treatment at diagnosis has limited efficacy and there is no standardised treatment at recurrence. New, personalised treatment options are under investigation, although challenges persist for heterogenous tumours such as GBM. Gene editing technologies are a game changer, enabling design of novel molecular-immunological treatments to be used in combination with chemoradiation, to achieve long lasting survival benefits for patients. Here, we review the literature on how cutting-edge molecular gene editing technologies can be applied to known and emerging tumour-associated antigens to enhance chimeric antigen receptor T and NK cell therapies for GBM. A tight balance of limiting neurotoxicity, avoiding tumour antigen loss and therapy resistance, while simultaneously promoting long-term persistence of the adoptively transferred cells must be maintained to significantly improve patient survival. We discuss the opportunities and challenges posed by the brain contexture to the administration of the treatments and achieving sustained clinical responses.

An Alternative Cell Therapy for Cancers: Induced Pluripotent Stem Cell (iPSC)-Derived Natural Killer Cells

Cell therapy is usually defined as the treatment or prevention of human disease by supplementation with cells that have been selected, manipulated, and pharmacologically treated or altered outside the body (ex vivo). Induced pluripotent stem cells (iPSCs), with their unique characteristics of indefinite expansion in cultures and genetic modifications, represent an ideal cell source for differentiation into specialized cell types. Cell therapy has recently become one of the most promising therapeutic approaches for cancers, and different immune cell types are selected as therapeutic platforms. Natural killer (NK) cells are shown to be effective tumor cell killers and do not cause graft-vs-host disease (GVHD), making them excellent candidates for, and facilitating the development of, "off-the-shelf" cell therapies. In this review, we summarize the progress in the past decade in the advent of iPSC technology and review recent developments in gene-modified iPSC-NK cells as readily available "off-the-shelf" cellular therapies.