Effective response and delayed toxicities of refractory advanced diffuse large B-cell lymphoma treated by CD20-directed chimeric antigen receptor-modified T cells

Alliance between titans: combination strategies of CAR-T cell therapy and oncolytic virus for the treatment of hematological malignancies

There have been several clinical studies using chimeric antigen receptor (CAR)-T cell therapy for different hematological malignancies. It has transformed the therapy landscape for hematologic malignancies dramatically. Nonetheless, in acute myeloid leukemia (AML) and T cell malignancies, it still has a dismal prognosis. Even in the most promising locations, recurrence with CAR-T treatment remains a big concern. Oncolytic viruses (OVs) can directly lyse tumor cells or cause immune responses, and they can be manipulated to create therapeutic proteins, increasing anticancer efficacy. Oncolytic viruses have been proven in a rising number of studies to be beneficial in hematological malignancies. There are limitations that cannot be avoided by using either treatment alone, and the combination of CAR-T cell therapy and oncolytic virus therapy may complement the disadvantages of individual application, enhance the advantages of their respective treatment methods and improve the treatment effect. The alternatives for combining two therapies in hematological malignancies are discussed in this article.

Activated CD4+ T Cell Proportion in the Peripheral Blood Correlates with the Duration of Cytokine Release Syndrome and Predicts Clinical Outcome after Chimeric Antigen Receptor T Cell Therapy

Objective Chimeric antigen receptor (CAR) T cell therapy is an emerging and effective therapy for relapsed or refractory diffuse large B cell lymphoma (R/R DLBCL). The characteristic toxicities of CAR T cell therapy include cytokine release syndrome (CRS) and prolonged cytopenia. We investigated the factors associated with these complications after CAR T cell therapy by analyzing lymphocyte subsets following CAR T cell infusion. Methods We retrospectively analyzed peripheral blood samples on days 7, 14, and 28 after tisagenlecleucel (tisa-cel) infusion by flow cytometry at our institution between June 2020 and September 2022. Patients Thirty-five patients with R/R DLBCL who received tisa-cel therapy were included. Results A flow cytometry-based analysis of blood samples from these patients revealed that the proportion of CD4+CD25+CD127+ T cells (hereafter referred to as "activated CD4+ T cells" ) among the total CD4+ T cells on day 7 after tisa-cel infusion correlated with the duration of CRS (r=0.79, p<0.01). In addition, a prognostic analysis of the overall survival (OS) using time-dependent receiver operating characteristic curves indicated a significantly more favorable OS and progression-free survival of patients with a proportion of activated CD4+ T cells among the total CD4+ T cells <0.73 (p=0.01, and p<0.01, respectively). Conclusion These results suggest that the proportion of activated CD4+ T cells on day 7 after tisa-cel infusion correlates with the CRS duration and predicts clinical outcomes after CAR T cell therapy. Further studies with a larger number of patients are required to validate these observations.

Rituximab potentially improves clinical outcomes of CAR-T therapy for r/r B-ALL via sensitizing leukemia cells to CAR-T-mediated cytotoxicity and reducing CAR-T exhaustion

PURPOSE

Despite chimeric antigen receptor (CAR) T-cell therapy has achieved great advances in recent year, approximately 50% of relapsed/refractory B cell acute lymphoblastic leukemia (r/r B-ALL) patients treated with CAR-T experience relapse 6 months post CAR-T treatment. CD20 express on 30 to 50% of B-ALL, which makes CD20 Monoclonal Antibody as one of the potential therapy strategies to decrease the tumor burden and improve the efficacy of CAR-T therapy. Adding Rituximab to chemotherapy protocol had been demonstrated to improve the outcome for CD20-positive ALL. However, rare study explored the influence of Rituximab combined with CAR-T therapy.

METHODS

We retrospectively analyzed 20 r/r B-ALL patients who received CAR-T therapy, all of whom had failed multiple lines of therapy. Before CAR-T infusion, we administered Rituximab to 10 patients with high CD20 expression at a dose of 375 mg/m2 for 1 day. Meanwhile, we selected 10 patients with the comparable features who underwent CAR-T treatment without Rituximab in the same period as the control group. In vitro, the surface molecule expression and killing of CAR-T post Rituximab-treated B-ALL cells co-incubated with CAR-T cells were detected by flow cytometry.

RESULTS

The median follow-up of Rituximab and Control groups were 29.27 and 9.83 months. We found that adding Rituximab may confer a favorable prognosis compared with Control group. The 2-year overall survival (OS) and leukemia-free survival (LFS) rates both were longer in the Rituximab group (90% vs. 26.7%, p = 0.0342; 41.7% vs. 25%, p = 0.308). In vitro, we observed that Rituximab-treated tumour cells are more sensitive to CAR-T killing and a broad range of cytokines and chemokines were produced when Rituximab-treated Nalm-6 cells co-cultured with 19-22CAR-T cells, such as interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α) and interleukin-2 (IL-2). To investigate whether Rituximab has an effect on CAR-T persistence, we stimulated CAR-T cells repeatedly in vitro with Rituximab-treated Nalm-6 to evaluate the changes in CAR-T surface exhaustion molecules at different times. We found that the expression of exhaustion molecules (LAG-3, PD-1, TIM-3) on CAR-T cells were significantly lower in the Rituximab group than in the Control group.

CONCLUSION

Rituximab combined with CAR-T therapy is effective for improving the long-term prognosis of B-ALL patients who have failed multiple lines of therapy. In vitro, we observed that rituximab potentially improves CAR-T efficacy by sensitizing ALL to CART-mediated cytotoxicity and reducing CAR-T exhaustion.

Redefining the battle against colorectal cancer: a comprehensive review of emerging immunotherapies and their clinical efficacy

Colorectal cancer (CRC) is the third most common cancer globally and presents a significant challenge owing to its high mortality rate and the limitations of traditional treatment options such as surgery, radiotherapy, and chemotherapy. While these treatments are foundational, they are often poorly effective owing to tumor resistance. Immunotherapy is a groundbreaking alternative that has recently emerged and offers new hope for success by exploiting the body's own immune system. This article aims to provide an extensive review of clinical trials evaluating the efficacy of various immunotherapies, including CRC vaccines, chimeric antigen receptor T-cell therapies, and immune checkpoint inhibitors. We also discuss combining CRC vaccines with monoclonal antibodies, delve into preclinical studies of novel cancer vaccines, and assess the impact of these treatment methods on patient outcomes. This review seeks to provide a deeper understanding of the current state of CRC treatment by evaluating innovative treatments and their potential to redefine the prognosis of patients with CRC.

CAR-T cell therapy in hematological malignancies: Where are we now and where are we heading for?

Chimeric antigen receptor T (CAR-T) therapy has emerged as a revolutionary new pillar in cancer care, particularly in relapsed/refractory (r/r) B-cell malignancies. Following impressive clinical outcomes in hematological malignancies, the FDA-approved six CAR-T cell products for indications such as lymphoma, leukemia, and myeloma. Despite the numerous advantages of CAR-T cell treatment, several challenges exist that interfere with its therapeutic efficacy. Serious adverse effects connected with the treatment continue to be a major concern. In addition, poor persistence of therapeutics and antigen escape frequently result in tumor relapse. Exorbitant treatment cost further remains a significant barrier to its effective implementation, limiting its accessibility. This review presents progress of CAR-T research, the key obstacles that hamper promising outcomes for patients with hematological malignancies, and a few strategies to overcome them.

Harnessing immunotherapy for brain metastases: insights into tumor-brain microenvironment interactions and emerging treatment modalities

Brain metastases signify a deleterious milestone in the progression of several advanced cancers, predominantly originating from lung, breast and melanoma malignancies, with a median survival timeframe nearing six months. Existing therapeutic regimens yield suboptimal outcomes; however, burgeoning insights into the tumor microenvironment, particularly the immunosuppressive milieu engendered by tumor-brain interplay, posit immunotherapy as a promising avenue for ameliorating brain metastases. In this review, we meticulously delineate the research advancements concerning the microenvironment of brain metastases, striving to elucidate the panorama of their onset and evolution. We encapsulate three emergent immunotherapeutic strategies, namely immune checkpoint inhibition, chimeric antigen receptor (CAR) T cell transplantation and glial cell-targeted immunoenhancement. We underscore the imperative of aligning immunotherapy development with in-depth understanding of the tumor microenvironment and engendering innovative delivery platforms. Moreover, the integration with established or avant-garde physical methodologies and localized applications warrants consideration in the prevailing therapeutic schema.

CAR-T cell therapy for hematological malignancies: History, status and promise

For many years, the methods of cancer treatment are usually surgery, chemotherapy and radiation therapy. Although these methods help to improve the condition, most tumors still have a poor prognosis. In recent years, immunotherapy has great potential in tumor treatment. Chimeric antigen receptor T-cell immunotherapy (CAR-T) uses the patient's own T cells to express chimeric antigen receptors. Chimeric antigen receptor (CAR) recognizes tumor-associated antigens and kills tumor cells. CAR-T has achieved good results in the treatment of hematological tumors. In 2017, the FDA approved the first CAR-T for the treatment of B-cell acute lymphoblastic leukemia (ALL). In October of the same year, the FDA approved CAR-T to treat B-cell lymphoma. In order to improve and enhance the therapeutic effect, CAR-T has become a research focus in recent years. The structure of CAR, the targets of CAR-T treatment, adverse reactions and improvement measures during the treatment process are summarized. This review is an attempt to highlight recent and possibly forgotten findings of advances in chimeric antigen receptor T cell for treatment of hematological tumors.

Characteristics of premanufacture CD8+T cells determine CAR-T efficacy in patients with diffuse large B-cell lymphoma

Although chimeric antigen receptor (CAR) T cells have become an important treatment option for patients with relapsed/refractory B-cell malignancies, more than 60% of patients with diffuse large B-cell lymphoma (DLBCL) treated with CAR-T cell therapies fail to achieve a durable response. To reveal changes in CAR-T cell therapy and identify response biomarkers, we conducted a retrospective analysis of pre-manufacture source T cells and CAR-T cell products and their association with outcome in 58 patients with r/rDLBCL who received tandem CD19/CD20 CAR-T cell therapy. We performed bulk RNA-Seq, single-cell RNA-Seq, and paired T cell receptor sequencing on CAR-T cell products and pre-manufacture T cells from DLBCL patients. We note that a CD8+ stem cell-like memory T cell population with a higher proportion and enhanced activating capacity of the CAR-T cell products was key to achieving durable clinical response. By analysing autologously-derived, pre-manufacture T cells, our data suggest that heterogeneity in the cellular and molecular features of pre-manufacture T cells contribute to the variation in efficacy after CAR-T cell therapy in DLBCL. The differences in anti-tumour efficacy of CAR-T cells among patients with different clinical outcomes appear to be due to the loss of CCR7 gene expression, coupled with increased expression of activation- and inhibitor-related genes in the CD8+ naïve-T cell populations among the apheresis T cells from patients with a poor molecular response. These findings significantly advance our understanding of the underlying molecular determinants of pre-manufacture T cell function.

Recent advances in CAR T-cell therapy for lymphoma in China

Lymphoma is a hematologic malignancy which mainly consists of Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). Although systemic chemotherapy, radiotherapy, and other advanced therapeutics, including rituximab or immune checkpoint inhibitors, have improved the prognosis in recent decades, there are still a number of patients with relapsed or refractory (R/R) lymphoma with a poor prognosis. Chimeric antigen receptor (CAR) T-cell therapy has provided a curative option for patients with relapsed or refractory lymphoma. Numerous clinical trials have been conducted worldwide and presented inspiring results that give insight into this breakthrough therapy. The development of cancer cell therapy in China has been rapid in the past years and dominates the field with the USA. This review aims to summarize the published results of CAR T-cell therapy alone or in combination with other therapies in mainland China, both in R/R NHL and R/R HL.

Exploring CAR-T Cell Therapy Side Effects: Mechanisms and Management Strategies

Chimeric antigen receptor (CAR) T cell therapy has revolutionized the treatment of malignancies, especially hematological tumors, but toxicities have tempered its success. The main impediments to the development of CAR-T cell therapies are the following: cytokine release syndrome (CRS), immune-effector-cell-associated neurotoxicity syndrome (ICANS), tumor lysis syndrome (TLS), and on-target/off-tumor toxicity (OTOT). This review summarizes these side effects' underlying mechanisms and manifestations over time. It provides potential prevention and treatment according to the consensus grading, stressing the significance of establishing strategies that anticipate, reduce, and navigate the beginning of these side effects. It is essential to fully comprehend the mechanisms underlying these toxicities to create efficient treatment and preventive approaches.

Nanobody-derived bispecific CAR-T cell therapy enhances the anti-tumor efficacy of T cell lymphoma treatment

T cell lymphoma (TCL) is a highly heterogeneous group of diseases with a poor prognosis and low 5-year overall survival rate. The current therapeutic regimens have relatively low efficacy rates. Clinical studies of single-target chimeric antigen receptor T cell (CAR-T cell) therapy in T lymphocytes require large and multiple infusions, increasing the risks and cost of treatment; therefore, optimizing targeted therapy is a way to improve overall prognosis. Despite significant advances in bispecific CAR-T cell therapy to avoid antigen escape in treatment of B cell lymphoma, applying this strategy to TCL requires further investigation. Here, we constructed an alpaca nanobody (Nb) phage library and generated high-affinity and -specificity Nbs targeting CD30 and CD5, respectively. Based on multiple rounds of screening, bispecific NbCD30-CD5-CAR T cells were constructed, and their superior anti-tumor effect against TCL was validated in vitro and in vivo. Our findings demonstrated that Nb-derived bispecific CAR-T cells significantly improved anti-tumor efficacy in TCL treatment compared with single-target CAR-T cells and bispecific single chain variable fragment (scFv)-derived CAR-T cells. Because Nbs are smaller and less immunogenic, the synergistic effect of Nb-based bispecific CAR-T cells may improve their safety and efficacy in future clinical applications.

The role of bone marrow microenvironment on CAR-T efficacy in haematologic malignancies

In recent years, chimeric antigen receptor-T (CAR-T) cell therapy has emerged as a novel immunotherapy method. It has shown significant therapeutic efficacy in the treatment of haematological B cell malignancies. In particular, the CAR-T therapy targeting CD19 has yielded unprecedented efficacy for acute B-lymphocytic leukaemia (B-ALL) and non-Hodgkin's lymphoma (NHL). In haematologic malignancies, tumour stem cells are more prone to stay in the regulatory bone marrow (BM) microenvironment (called niches), which provides a protective environment against immune attack. However, how the BM microenvironment affects the anti-tumour efficacy of CAR-T cells and its underlying mechanism is worthy of attention. In this review, we discuss the role of the BM microenvironment on the efficacy of CAR-T in haematological malignancies and propose corresponding strategies to enhance the anti-tumour activity of CAR-T therapy.

Recent Advances in Molecular Mechanisms of Cancer Immunotherapy

Cancer is among the current leading causes of death worldwide, despite the novel advances that have been made toward its treatment, it is still considered a major public health concern. Considering both the serious impact of cancer on public health and the significant side effects and complications of conventional therapeutic options, the current strategies towards targeted cancer therapy must be enhanced to avoid undesired toxicity. Cancer immunotherapy has become preferable among researchers in recent years compared to conventional therapeutic options, such as chemotherapy, surgery, and radiotherapy. The understanding of how to control immune checkpoints, develop therapeutic cancer vaccines, genetically modify immune cells as well as enhance the activation of antitumor immune response led to the development of novel cancer treatments. In this review, we address recent advances in cancer immunotherapy molecular mechanisms. Different immunotherapeutic approaches are critically discussed, focusing on the challenges, potential risks, and prospects involving their use.

Rational Protein Design Yields a CD20 CAR with Superior Antitumor Efficacy Compared with CD19 CAR

Chimeric antigen receptors (CAR) are fusion proteins whose functional domains are often connected in a plug-and-play manner to generate multiple CAR variants. However, CARs with highly similar sequences can exhibit dramatic differences in function. Thus, approaches to rationally optimize CAR proteins are critical to the development of effective CAR T-cell therapies. Here, we report that as few as two amino-acid changes in nonsignaling domains of a CAR were able to significantly enhance in vivo antitumor efficacy. We demonstrate juxtamembrane alanine insertion and single-chain variable fragment sequence hybridization as two strategies that could be combined to maximize CAR functionality, and describe a CD20 CAR that outperformed the CD19 CAR in antitumor efficacy in preclinical in vitro and in vivo assays. Precise changes in the CAR sequence drove dramatically different transcriptomic profiles upon antigen stimulation, with the most efficacious CAR inducing an enrichment in highly functional memory T cells upon antigen stimulation. These findings underscore the importance of sequence-level optimization to CAR T-cell function, and the protein-engineering strategy described here may be applied to the development of additional CARs against diverse antigens. See related Spotlight by Scheller and Hudecek, p. 142.

Combating challenges in CAR-T cells with engineering immunology

Chimeric antigen receptors (CAR) T cells (CAR-T) mark a significant step towards producing safe and effective personal anticancer treatments. CAR-T strategies engineers the T cells from the patients to allow specific binding to a tumour-specific antigen. CAR-Ts are a second-wave offensive strategy to clear out remaining chemotherapy-resistant tumour cells. Though showing practical antitumor abilities in multiple haematological malignancies and solid tumour cancers, the issues of antigen escape, tumour infiltration/penetration, and toxicity side effects limit the usage of prolonged CAR-T therapies. However, engineering immunology has exploited human stem cell-based CAR-T therapies and the development of CAR-M (macrophage) therapies to combat the disadvantages of conventional CAR-T therapies. In this review, we will highlight the challenges of CAR-T therapies and combat them with engineering immunology for cancer immunotherapy.

Recent findings on chimeric antigen receptor (CAR)-engineered immune cell therapy in solid tumors and hematological malignancies

Advancements in adoptive cell therapy over the last four decades have revealed various new therapeutic strategies, such as chimeric antigen receptors (CARs), which are dedicated immune cells that are engineered and administered to eliminate cancer cells. In this context, CAR T-cells have shown significant promise in the treatment of hematological malignancies. However, many obstacles limit the efficacy of CAR T-cell therapy in both solid tumors and hematological malignancies. Consequently, CAR-NK and CAR-M cell therapies have recently emerged as novel therapeutic options for addressing the challenges associated with CAR T-cell therapies. Currently, many CAR immune cell trials are underway in various human malignancies around the world to improve antitumor activity and reduce the toxicity of CAR immune cell therapy. This review will describe the comprehensive literature of recent findings on CAR immune cell therapy in a wide range of human malignancies, as well as the challenges that have emerged in recent years.

CAR T-Cell-Based gene therapy for cancers: new perspectives, challenges, and clinical developments

Chimeric antigen receptor (CAR)-T cell therapy is a progressive new pillar in immune cell therapy for cancer. It has yielded remarkable clinical responses in patients with B-cell leukemia or lymphoma. Unfortunately, many challenges remain to be addressed to overcome its ineffectiveness in the treatment of other hematological and solidtumor malignancies. The major hurdles of CAR T-cell therapy are the associated severe life-threatening toxicities such as cytokine release syndrome and limited anti-tumor efficacy. In this review, we briefly discuss cancer immunotherapy and the genetic engineering of T cells and, In detail, the current innovations in CAR T-cell strategies to improve efficacy in treating solid tumors and hematologic malignancies. Furthermore, we also discuss the current challenges in CAR T-cell therapy and new CAR T-cell-derived nanovesicle therapy. Finally, strategies to overcome the current clinical challenges associated with CAR T-cell therapy are included as well.

CAR-T Cell Therapy in Hematological Malignancies: Current Opportunities and Challenges

Chimeric antigen receptor T (CAR-T) cell therapy represents a major breakthrough in cancer treatment, and it has achieved unprecedented success in hematological malignancies, especially in relapsed/refractory (R/R) B cell malignancies. At present, CD19 and BCMA are the most common targets in CAR-T cell therapy, and numerous novel therapeutic targets are being explored. However, the adverse events related to CAR-T cell therapy might be serious or even life-threatening, such as cytokine release syndrome (CRS), CAR-T-cell-related encephalopathy syndrome (CRES), infections, cytopenia, and CRS-related coagulopathy. In addition, due to antigen escape, the limited CAR-T cell persistence, and immunosuppressive tumor microenvironment, a considerable proportion of patients relapse after CAR-T cell therapy. Thus, in this review, we focus on the progress and challenges of CAR-T cell therapy in hematological malignancies, such as attractive therapeutic targets, CAR-T related toxicities, and resistance to CAR-T cell therapy, and provide some practical recommendations.

CD20-specific chimeric antigen receptor-expressing T cells as salvage therapy in rituximab-refractory/relapsed B-cell non-Hodgkin lymphoma

BACKGROUND AIMS

The infusion of chimeric antigen receptor (CAR) T cells that target specific tumor-associated antigens is a promising strategy that has exhibited encouraging results in clinical trials. However, few studies have focused on the effectiveness and safety of CD20 CAR T cells in rituximab-refractory/relapsed (R/R) B-cell non-Hodgkin lymphoma (B-NHL) patients, particularly those treated with rituximab for a short time. This prospective study aimed to assess the effectiveness and toxicity of CD20 CAR T cells in R/R B-NHL patients previously treated with rituximab.

METHODS

The authors conducted a prospective, single-center phase I study on the effectiveness and toxicity of CD20 CAR T cells in rituximab-treated R/R B-NHL patients (no. ChiCTR2000036350). A total of 15 patients with R/R B-NHL were enrolled between November 21, 2017, and December 1, 2021.

RESULTS

An overall response rate of 100% was shown in enrolled patients, with 12 (80%) achieving complete remission and three (20%) achieving partial remission for the best response. The median follow-up time was 12.4 months. Progression-free survival and overall survival were not yet reached by the data cutoff day. No patient developed grade 4 cytokine release syndrome, and only one patient had immune effector cell-associated neurotoxicity syndrome.

CONCLUSIONS

All enrolled B-NHL patients who were previously R/R to rituximab achieved different degrees of clinical response with tolerable toxicities. Notably, patients who had received rituximab within 3 months had a poorer prognosis.

Progress on CAR-T cell therapy for hematological malignancies

Chimeric antigen receptor (CAR) T cell therapy is an effective treatment for hematological malignancies, which have experienced the development of CD19 CAR-T cells for B lymphoblastic leukemia and lymphoma, B cell maturation antigen (BCMA) CAR-T cells for multiple myeloid, and more recently, the development of CD7 CAR-T cells for T cell malignancies. There are more obstacles for myeloid malignancies compared to other hematological malignancies in this field, thus concerning researches are in more diverse ways. In order to obtain more effective clinical CAR-T cells with lower side effects, scientists have developed multi-target CAR-T cells, universal CAR-T cells, as well as CAR-T cells, CAR-NK cells, CAR-iMac cells derived from induced pluripotent stem cells (iPSC) by genetic engineering. Chinese scientists have made significant contribution to the invention and manufacture of origin CAR-T cells and the establishment of an intact clinical research system. This review introduces the latest progress involving CAR-T cell therapy for hematological malignancies including B lymphoblastic malignancies, T lymphoblastic malignancies and myeloid malignancies, and also discuss the future developments including multi-target, universal and iPSC-derived CAR-related cell therapy.

Reprogramming the tumor microenvironment by genome editing for precision cancer therapy

The tumor microenvironment (TME) is essential for immune escape by tumor cells. It plays essential roles in tumor development and metastasis. The clinical outcomes of tumors are often closely related to individual differences in the patient TME. Therefore, reprogramming TME cells and their intercellular communication is an attractive and promising strategy for cancer therapy. TME cells consist of immune and nonimmune cells. These cells need to be manipulated precisely and safely to improve cancer therapy. Furthermore, it is encouraging that this field has rapidly developed in recent years with the advent and development of gene editing technologies. In this review, we briefly introduce gene editing technologies and systematically summarize their applications in the TME for precision cancer therapy, including the reprogramming of TME cells and their intercellular communication. TME cell reprogramming can regulate cell differentiation, proliferation, and function. Moreover, reprogramming the intercellular communication of TME cells can optimize immune infiltration and the specific recognition of tumor cells by immune cells. Thus, gene editing will pave the way for further breakthroughs in precision cancer therapy.

Recent Advances in CAR T-Cell Therapy for Patients with Chronic Lymphocytic Leukemia

Simple Summary

Outcomes for patients with chronic lymphocytic leukemia (CLL) have significantly improved over the past decade with the introduction of targeted therapies. These medications have improved survival, with good tolerability. However, for patients in need of treatment who are refractory or intolerant to targeted therapies treatment options are limited and survival is poor. Chimeric antigen receptor T cell therapy (CAR T cell) holds great promise as a potential treatment for patients with high-risk CLL who fail conventional treatment; however, its use to date has been limited. Here we summarize the literature and treatment considerations of CAR T cell therapy for patients with CLL.

Abstract

Chimeric antigen receptor T cells (CAR T cells) have resulted in dramatic treatment responses for patients with hematologic malignancies, resulting in improved survival for patients with intractable disease. The first patient treated with CD19 directed CAR T cell therapy had chronic lymphocytic leukemia (CLL) and achieved a complete remission. Subsequent clinical trials have focused largely on patients with other B-cell hematologic malignancies, owing to the fact that CAR T cell therapy for patients with CLL has met with challenges. More recent clinical trials have demonstrated CAR T cell therapy can be well tolerated and effective for patients with CLL, making it a potential treatment option for patients with this disease. In this article we review the background on CAR T cells for the treatment of patients with CLL, focusing on the unique obstacles that patients with CLL present for the development of adoptive T cell therapy, and the novel approaches currently under development to overcome these hurdles.

When Onco-Immunotherapy Meets Cold Atmospheric Plasma: Implications on CAR-T Therapies

T cells engineered with chimeric antigen receptors (CAR) have demonstrated its widespread efficacy as a targeted immunotherapeutic modality. Yet, concerns on its specificity, efficacy and generalization prevented it from being established into a first-line approach against cancers. By reviewing challenges limiting its clinical application, ongoing efforts trying to resolve them, and opportunities that emerging oncotherapeutic modalities may bring to temper these challenges, we conclude that careful CAR design should be done to avoid the off-tumor effect, enhance the efficacy of solid tumor treatment, improve product comparability, and resolve problems such as differential efficacies of co-stimulatory molecules, cytokine storm, tumor lysis syndrome, myelosuppression and severe hepatotoxicity. As a promising solution, we propose potential synergies between CAR-T therapies and cold atmospheric plasma, an emerging onco-therapeutic strategy relying on reactive species, towards improved therapeutic efficacies and enhanced safety that deserve extensive investigations.

Beyond CD19 CAR-T cells in lymphoma

Adoptive transfer of CD19-specific chimeric antigen receptor T-cells (CAR-T cells) has transformed the treatment paradigm of relapsed/refractory (R/R) CD19 B-cell malignancies, dramatically improving remission rates and cures in patients with chemo-refractory disease. However, the applicability of CD19 CAR-T cells is limited to B cell malignancies and antigen loss can result in treatment failure, prompting the exploration of alternative targets to overcome tumor escape via CD19 antigen loss, as well as extend the CAR-T cell platform to treat Hodgkin and T cell lymphomas. This review highlights recent clinical trials testing CAR-T cell targets beyond CD19.

Novel In Vivo and In Vitro Pharmacokinetic/Pharmacodynamic-Based Human Starting Dose Selection for Glofitamab

We present a novel approach for first-in-human (FIH) dose selection of the CD20xCD3 bispecific antibody, glofitamab, based on pharmacokinetic/pharmacodynamic (PKPD) assessment in cynomolgus monkeys to select a high, safe starting dose, with cytokine release (CR) as the PD endpoint. Glofitamab pharmacokinetics were studied in mice and cynomolgus monkeys; PKPD of IL-6, TNF-α and interferon-γ release following glofitamab, with/without obinutuzumab pretreatment (Gpt) was studied in cynomolgus monkeys. Potency differences for CR between cynomolgus monkeys and humans were determined by glofitamab incubation in whole blood of both species. The PKPD model for CR was translated to humans to project a starting dose that did not induce CR exceeding a clinically-predefined threshold. In cynomolgus monkeys, glofitamab showed a species-specific atypical high clearance, with and without B-cell debulking by Gpt. CR was related to glofitamab serum levels and B-cell counts. B-cell reduction by Gpt led to a marked decrease in CR. FIH starting dose (5 µg) was selected based on IL-6 release considering the markedly higher glofitamab in vitro potency in human vs monkey blood. This is a novel PKPD-based approach for selection of FIH starting dose for a CD20xCD3 bispecific antibody in B-cell lymphoma, evidenced in the glofitamab study, NP30179 (NCT03075696).

Genetic Modification of Cytokine Signaling to Enhance Efficacy of CAR T Cell Therapy in Solid Tumors

Chimeric antigen receptor (CAR) T cell therapy has shown unprecedented success in treating advanced hematological malignancies. Its effectiveness in solid tumors has been limited due to heterogeneous antigen expression, a suppressive tumor microenvironment, suboptimal trafficking to the tumor site and poor CAR T cell persistence. Several approaches have been developed to overcome these obstacles through various strategies including the genetic engineering of CAR T cells to blunt the signaling of immune inhibitory receptors as well as to modulate signaling of cytokine/chemokine molecules and their receptors. In this review we offer our perspective on how genetically modifying cytokine/chemokine molecules and their receptors can improve CAR T cell qualities such as functionality, persistence (e.g. resistance to pro-apoptotic signals) and infiltration into tumor sites. Understanding how such modifications can overcome barriers to CAR T cell effectiveness will undoubtedly enhance the potential of CAR T cells against solid tumors.

Chimeric antigen receptor (CAR) T-cell therapy for people with relapsed or refractory diffuse large B-cell lymphoma

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is an aggressive cancer of the lymphatic system. About 30% to 40% of people with DLBCL experience relapse and 10% are refractory to first-line treatment usually consisting of R-CHOP chemotherapy. Of those eligible for second-line treatment, commonly consisting of salvage chemotherapy followed by autologous stem-cell transplantation (ASCT), around 50% experience relapse. With a median overall survival of less than six to 12 months, the prognosis of individuals who relapse or are refractory (r/r) to advanced lines of treatment or of those who are ineligible for ASCT, is very poor. With the introduction of chimeric antigen receptor (CAR) T-cell therapy, a novel treatment option for these people is available.

OBJECTIVES

To assess the benefits and harms of chimeric antigen receptor (CAR) T-cell therapy for people with relapsed or refractory (r/r) DLBCL.

SEARCH METHODS

An experienced information specialist performed a systematic database search for relevant articles on CENTRAL, MEDLINE and Embase until September 11th, 2020. We also searched trial registries and reference lists of identified studies up to this date. All search results were screened by two authors independently and a third author was involved in case of discrepancies.

SELECTION CRITERIA

We included prospectively planned trials evaluating CAR T-cell therapy for people with r/r DLBCL. We had planned to include randomised controlled trials (RCTs) and we flexibly adapted eligibility criteria to the most reliable study designs available. We excluded studies involving fewer than 10 participants with r/r DLBCL and studies with a proportion of participants with r/r DLBCL below 70%, unless data were reported separately for this subgroup.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data and performed risk of bias ratings independently. A third author was involved in case of disagreements. As our search did not yield any completed RCTs, prospective controlled non-randomised studies of interventions (NRSIs) or prospective observational studies with a control group, we did not meta-analyse data and reported all results narratively. We adopted the GRADE approach to assess the certainty of the evidence for prioritised outcomes.

MAIN RESULTS

We identified 13 eligible uncontrolled studies evaluating a single or multiple arms of CAR T-cell therapies. We also identified 38 ongoing studies, including three RCTs. Ten studies are awaiting classification due to completion with no retrievable results data or insufficient data to justify inclusion. The mean number of participants enrolled, treated with CAR T-cell therapy and evaluated in the included studies were 79 (range 12 to 344; data unavailable for two studies), 61 (range 12 to 294; data unavailable for one study) and 52 (range 11 to 256), respectively. Most studies included people with r/r DLBCL among people with other haematological B-cell malignancies. Participants had received at least a median of three prior treatment lines (data unavailable for four studies), 5% to 50% had undergone ASCT (data unavailable for five studies) and, except for two studies, 3% to 18% had undergone allogenic stem-cell transplantation (data unavailable for eight studies). The overall risk of bias was high for all studies, in particular, due to incomplete follow-up and the absence of blinding. None of the included studies had a control group so that no adequate comparative effect measures could be calculated. The duration of follow-up varied substantially between studies, in particular, for harms. Our certainty in the evidence is very low for all outcomes. Overall survival was reported by eight studies (567 participants). Four studies reported survival rates at 12 months which ranged between 48% and 59%, and one study reported an overall survival rate of 50.5% at 24 months. The evidence is very uncertain about the effect of CAR T-cell therapy on overall survival. Two studies including 294 participants at baseline and 59 participants at the longest follow-up (12 months or 18 months) described improvements of quality of life measured with the EuroQol 5-Dimension 5-Level visual analogue scale (EQ-5D-5L VAS) or Function Assessment of Cancer Therapy-Lymphoma (FACT-Lym). The evidence is very uncertain about the effect of CAR T-cell therapy on quality of life. None of the studies reported treatment-related mortality. Five studies (550 participants) reported the occurrence of adverse events among participants, ranging between 99% and 100% for any grade adverse events and 68% to 98% for adverse events grade ≥ 3. In three studies (253 participants), 56% to 68% of participants experienced serious adverse events, while in one study (28 participants), no serious adverse events occurred. CAR T-cell therapy may increase the risk of adverse events and serious adverse events but the evidence is very uncertain about the exact risk. The occurrence of cytokine release syndrome (CRS) was reported in 11 studies (675 participants) under use of various grading criteria. Five studies reported between 42% and 100% of participants experiencing CRS according to criteria described in Lee 2014. CAR T-cell therapy may increase the risk of CRS but the evidence is very uncertain about the exact risk. Nine studies (575 participants) reported results on progression-free survival, disease-free survival or relapse-free survival. Twelve-month progression-free survival rates were reported by four studies and ranged between 44% and 75%. In one study, relapse-free survival remained at a rate of 64% at both 12 and 18 months. The evidence is very uncertain about the effect of CAR T-cell therapy on progression-free survival. Thirteen studies (620 participants) provided data on complete response rates. At six months, three studies reported complete response rates between 40% and 45%. The evidence is very uncertain about the effect of CAR T-cell therapy on complete response rates.

AUTHORS' CONCLUSIONS

The available evidence on the benefits and harms of CAR T-cell therapy for people with r/r DLBCL is limited, mainly because of the absence of comparative clinical trials. The results we present should be regarded in light of this limitation and conclusions should be drawn very carefully. Due to the uncertainty in the current evidence, a large number of ongoing investigations and a risk of substantial and potentially life-threatening complications requiring supplementary treatment, it is critical to continue evaluating the evidence on this new therapy.

CAR T-Cell Therapy in Hematological Malignancies

Chimeric antigen receptor (CAR) T-cells (CAR T-cells) are a promising therapeutic approach in treating hematological malignancies. CAR T-cells represent engineered autologous T-cells, expressing a synthetic CAR, targeting tumor-associated antigens (TAAs) independent of major histocompatibility complex (MHC) presentation. The most common target is CD19 on B-cells, predominantly used for the treatment of lymphoma and acute lymphocytic leukemia (ALL), leading to approval of five different CAR T-cell therapies for clinical application. Despite encouraging clinical results, treatment of other hematological malignancies such as acute myeloid leukemia (AML) remains difficult. In this review, we focus especially on CAR T-cell application in different hematological malignancies as well as strategies for overcoming CAR T-cell dysfunction and increasing their efficacy.

Chimeric antigen receptor T-cells (CARs) in cancer treatment

BACKGROUND

Cancer is one of the leading causes of death worldwide. Chemotherapy, radiation therapy, and stem cell transplantation were the main cancer treatment approaches for several years but due to their limited effectiveness, there was a constant search for new therapeutic approaches. Cancer immunotherapy that utilizes and enhances the normal capacity of the patient's immune system was used to fight against cancer. Genetically engineered T-cells that express chimeric antigen receptors (CARs) showed remarkable anti-tumor activity against hematologic malignancies and is now being investigated in a variety of solid tumors. The use of this therapy in the last few years has been successful, achieving a great success in improving the quality of life and prolonging the survival time of patients with a reduction in remission rates. However, many challenges still need to be resolved in order for this technology to gain widespread adoption. <P> Objective: This review summarizes various experimental approaches towards the use of CAR T-cells in hematologic malignancies and solid tumors. <P> Conclusion: Finally, we address the challenges posed by CAR T-cells and discuss strategies for improving the performance of these T cells in fighting cancers.

Treatment-Related Adverse Events of Chimeric Antigen Receptor T-Cell (CAR T) in Clinical Trials: A Systematic Review and Meta-Analysis

Simple Summary

Successful treatment of hematological malignancies with chimeric antigen receptors T (CAR-T) cells has led to much enthusiasm for the wide clinical usage and development of novel CAR-T therapies. However, it also challenges physicians and investigators to recognize and deal with treatment-associated toxicities. We conducted a systematic review and meta-analysis from 84 eligible study and a total of 2592 patients to identify the comprehensive incidences and severity of CRS and neurological symptoms (NS) as well as the potential differences in AEs across a variety of cancer types, CAR-T targets, and other factors, thereby offering a significant implication on its future application and research.

Abstract

Chimeric antigen receptors T (CAR-T) cell therapy of cancer is a rapidly evolving field. It has been shown to be remarkably effective in cases of hematological malignancies, and its approval by the FDA has significantly increased the enthusiasm for wide clinical usage and development of novel CAR-T therapies. However, it has also challenged physicians and investigators to recognize and deal with treatment-associated toxicities. A total of 2592 patients were included from 84 eligible studies that were systematically searched and reviewed from the databases of PubMed, de, the American Society of Hematology and the Cochrane Library. The meta-analysis and subgroup analysis by a Bayesian logistic regression model were used to evaluate the incidences of therapy-related toxicities such as cytokine release syndrome (CRS) and neurological symptoms (NS), and the differences between different targets and cancer types were analyzed. The pooled all-grade CRS rate and grade ≥ 3 CRS rate was 77% and 29%, respectively, with a significantly higher incidence in the hematologic malignancies (all-grade: 81%; grade ≥ 3: 29%) than in solid tumors (all-grade: 37%; grade ≥ 3: 19%). The pooled estimate NS rate from the individual studies were 40% for all-grade and 28% for grade ≥ 3. It was also higher in the hematologic subgroup than in the solid tumors group. The subgroup analysis by cancer type showed that higher incidences of grade ≥ 3 CRS were observed in anti-CD19 CAR-T therapy for ALL and NHL, anti-BCMA CAR-T for MM, and anti-CEA CAR-T for solid tumors, which were between 24–36%, while higher incidences of grade ≥ 3 NS were mainly observed in CD19-ALL/NHL (23–37%) and BCMA-MM (12%). Importantly, subgroup analysis on anti-CD19 CAR-T studies showed that young patients (vs. adult patients), allologous T cell origin (vs. autologous origin), gamma retrovirus vector, and higher doses of CAR-T cells were associated with high-grade CRS. On the other hand, the patients with NHL (vs ALL), administered with higher dose of CAR-T, and adult patients (vs. young patients) had an increased incidence of grade ≥ 3 NS events. This study offers a comprehensive summary of treatment-related toxicity and will guide future clinical trials and therapeutic designs investigating CAR T cell therapy.

[Analysis of local reactions and efficacy of CD19 chimeric antigen receptor-modified T cells therapy in recurrent/refractory B-cell lymphoma with >7.5 cm lesions]

目的

观察病灶>7.5 cm的复发/难治B细胞非霍奇金淋巴瘤（R/R NHL）患者CD19嵌合抗原受体T细胞（CAR-T细胞）治疗的肿瘤局部反应及疗效。

方法

以2018年8月至2020年5月接受CD19 CAR-T细胞治疗的病灶>7.5 cm的32例R/R NHL患者为研究对象，流式细胞仪检测CD19CAR-T细胞的体内扩增情况；酶联免疫吸附测定法检测患者外周血中细胞因子水平；观察全身不良反应及肿瘤局部反应，分析总有效率（ORR）及总生存（OS）情况。

结果

① 32例患者CAR-T细胞治疗后，13例获得完全缓解（CR）（40.63％），10例获得部分缓解（PR）（31.25％），ORR为71.88％。② 23例有效患者均发生细胞因子释放综合征（CRS），其中1～2级13例，3～4级10例；而疾病稳定+疾病进展（SD+PD）组9例患者CRS均为1～2级（P＝0.030）。③共15例（46.9％）患者发生肿瘤局部反应，其中CR 9例、PR 5例、SD 1例，肿瘤局部反应包括：浅表肿物直径增大且伴红肿热痛；深部肿物表现为腹痛、腹胀、憋气以及肿瘤局部疼痛、烧灼，瘤体增大或伴局部水肿；肿瘤局部出现渗出性病变，可见于腹腔、胸膜腔等。④有效组CD19 CAR-T细胞峰值高于SD+PD组［16.8％（5.3％～48.2％）对2.9％（1.5％～5.7％），z＝−4.297，P<0.001］，有效组中出现肿瘤局部反应患者CD19 CAR-T细胞峰值高于未出现肿瘤局部反应患者［22.2％（10.5％～48.2％）对12.6％（5.3％～21.6％），z＝−3.213，P＝0.001］，多发肿块组CD19 CAR-T细胞峰值高于单发肿块组［35.8％（1.5％～48.2％）对16.8％（10.5％～18.5％），z＝−2.023，P＝0.040］。⑤肿瘤局部反应出现和瘤体缩小时间，均较全身不良反应时间延迟。⑥有效患者中出现肿瘤局部反应者OS率高于未出现肿瘤局部反应者，但差异无统计学意义（75.0％对34.6％，P＝0.169）。

结论

病灶>7.5 cm的R/R NHL患者CD19 CAR-T细胞治疗，近一半出现肿瘤局部反应，发生时间迟于全身不良反应开始的时间。临床试验注册：中国临床试验注册中心（ChiCTR1800018059）

Advances in chimeric antigen receptor T-cell therapy for B-cell non-Hodgkin lymphoma

B-cell non-Hodgkin lymphoma (B-NHL) is a group of heterogeneous disease which remains incurable despite developments of standard chemotherapy regimens and new therapeutic agents in decades. Some individuals could have promising response to standard therapy while others are unresponsive to standard chemotherapy or relapse after autologous hematopoietic stem-cell transplantation (ASCT), which indicates the necessity to develop novel therapies for refractory or relapsed B-NHLs. In recent years, a novel cell therapy, chimeric antigen receptor T-cell therapy (CAR-T), was invented to overcome the limitation of traditional treatments. Patients with aggressive B-NHL are considered for CAR-T cell therapy when they have progressive lymphoma after second-line chemotherapy, relapse after ASCT, or require a third-line therapy. Clinical trials of anti-CD19 CAR-T cell therapy have manifested encouraging efficacy in refractory or relapsed B-NHL. However, adverse effects of this cellular therapy including cytokine release syndrome, neurotoxicity, tumor lysis syndrome and on-target, off-tumor toxicities should attract our enough attention despite the great anti-tumor effects of CAR-T cell therapy. Although CAR-T cell therapy has shown remarkable results in patients with B-NHL, the outcomes of patients with B-NHL were inferior to patients with acute lymphoblastic leukemia. The inferior response rate may be associated with physical barrier of lymphoma, tumor microenvironment and low quality of CAR-T cells manufactured from B-NHL patients. Besides, some patients relapsed after anti-CD19 CAR-T cell therapy, which possibly were due to limited CAR-T cells persistence, CD19 antigen escape or antigen down-regulation. Quite a few new antigen-targeted CAR-T products and new-generation CAR-T, for example, CD20-targeted CAR-T, CD79b-targeted CAR-T, CD37-targeted CAR-T, multi-antigen-targeted CAR-T, armored CAR-T and four-generation CAR-T are developing rapidly to figure out these deficiencies.

The "Magic Bullet" Is Here? Cell-Based Immunotherapies for Hematological Malignancies in the Twilight of the Chemotherapy Era

Despite the introduction of a plethora of different anti-neoplastic approaches including standard chemotherapy, molecularly targeted small-molecule inhibitors, monoclonal antibodies, and finally hematopoietic stem cell transplantation (HSCT), there is still a need for novel therapeutic options with the potential to cure hematological malignancies. Although nowadays HSCT already offers a curative effect, its implementation is largely limited by the age and frailty of the patient. Moreover, its efficacy in combating the malignancy with graft-versus-tumor effect frequently coexists with undesirable graft-versus-host disease (GvHD). Therefore, it seems that cell-based adoptive immunotherapies may constitute optimal strategies to be successfully incorporated into the standard therapeutic protocols. Thus, modern cell-based immunotherapy may finally represent the long-awaited "magic bullet" against cancer. However, enhancing the safety and efficacy of this treatment regimen still presents many challenges. In this review, we summarize the up-to-date state of the art concerning the use of CAR-T cells and NK-cell-based immunotherapies in hemato-oncology, identify possible obstacles, and delineate further perspectives.

Radiation Priming Chimeric Antigen Receptor T-Cell Therapy in Relapsed/Refractory Diffuse Large B-Cell Lymphoma With High Tumor Burden

Chimeric antigen receptor T-cell (CAR-T) therapy demonstrates impressive efficacy in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). However, CAR-T therapy-related severe cytokine release syndrome and neurological toxicity limit its clinical application in R/R DLBCL patients with high tumor burden. Here, we conducted a phase II clinical trial testing the efficacy and toxicities of CAR-T therapy in R/R non-Hodgkin lymphoma patients (NCT03196830). Among the enrolled patients, 10 R/R DLBCL patients with high tumor burden were analyzed. Before CAR-T therapy, 4 were treated with intensive combined chemotherapy (C-CAR-cohort), and 6 were exposed to radiotherapy (R-CAR-cohort). Patients in the R-CAR-T-cohort showed a higher overall response rate (100% vs. 25%, P=0.033) and less severe cytokine release syndrome (0% vs. 100%, P=0.0048) and neurotoxicity (0% vs. 75%, P=0.033) incidences than patients in the C-CAR-T-cohort. Furthermore, one case who responded to CAR-T therapy initially and who suffered a relapse shortly was exposed to radiation and achieved complete remission, with an increase in the number of CAR-T copies detected. This study demonstrates that radiotherapy is an optimal debulking regimen to managing R/R DLBCL patients before CAR-T therapy and a promising alternative salvage therapy for patients who suffer a relapse after CAR-T therapy by fuelling CAR-T copies.

Reactions Related to CAR-T Cell Therapy

The application of chimeric antigen receptor (CAR) T-cell therapy as a tumor immunotherapy has received great interest in recent years. This therapeutic approach has been used to treat hematological malignancies solid tumors. However, it is associated with adverse reactions such as, cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), off-target effects, anaphylaxis, infections associated with CAR-T-cell infusion (CTI), tumor lysis syndrome (TLS), B-cell dysplasia, hemophagocytic lymphohistiocytosis (HLH)/macrophage activation syndrome (MAS) and coagulation disorders. These adverse reactions can be life-threatening, and thus they should be identified early and treated effectively. In this paper, we review the adverse reactions associated with CAR-T cells, the mechanisms driving such adverse reactions, and strategies to subvert them. This review will provide important reference data to guide clinical application of CAR-T cell therapy.

The regulation and function of CD20: an "enigma" of B-cell biology and targeted therapy

The introduction of anti-CD20 monoclonal antibodies such as rituximab, ofatumumab, or obinutuzumab improved the therapy of B-cell malignancies even though the precise physiological role and regulation of CD20 remains unclear. Furthermore, CD20 expression is highly variable between different B-cell malignancies, patients with the same malignancy, and even between intraclonal subpopulations in an individual patient. Several epigenetic (EZH2, HDAC1/2, HDAC1/4, HDAC6, complex Sin3A-HDAC1) and transcription factors (USF, OCT1/2, PU.1, PiP, ELK1, ETS1, SP1, NFκB, FOXO1, CREM, SMAD2/3) regulating CD20 expression (encoded by MS4A1) have been characterized. CD20 is induced in the context of microenvironmental interactions by CXCR4/SDF1 (CXCL12) chemokine signaling and the molecular function of CD20 has been linked to the signaling propensity of B-cell receptor (BCR). CD20 has also been shown to interact with multiple other surface proteins on B cells (such as CD40, MHCII, CD53, CD81, CD82, and CBP). Current efforts to combine anti-CD20 monoclonal antibodies with BCR signaling inhibitors targeting BTK or PI3K (ibrutinib, acalabrutinib, idelalisib, duvelisib) or BH3-mimetics (venetoclax) lead to the necessity to better understand both the mechanisms of regulation and the biological functions of CD20. This is underscored by the observation that CD20 is decreased in response to the "BCR inhibitor" ibrutinib which largely prevents its successful combination with rituximab. Several small molecules (such as histone deacetylase inhibitors, DNA methyl-transferase inhibitors, aurora kinase A/B inhibitors, farnesyltransferase inhibitors, FOXO1 inhibitors, and bryostatin-1) are being tested to upregulate cell-surface CD20 levels and increase the efficacy of anti-CD20 monoclonal antibodies. Herein, we review the current understanding of CD20 function, and the mechanisms of its regulation in normal and malignant B cells, highlighting the therapeutic implications.

Clinical development of CAR T cell therapy in China: 2020 update

Chimeric antigen receptor (CAR) T-cell therapy has achieved significant success in the treatment of hematological malignancies. In recent years, fast-growing CAR T clinical trials have actively explored their potential application scenarios. According to the data from the clinicaltrials.gov website, China became the country with the most registered CAR T trials in September 2017. As of June 30, 2020, the number of registered CAR T trials in China has reached 357. In addition, as many as 150 other CAR T trials have been registered on ChiCTR. Although CAR T therapy is flourishing in China, there are still some problems that cannot be ignored. In this review, we aim to systematically summarize the clinical practice of CAR T-cell therapy in China. This review will provide an informative reference for colleagues in the field, and a better understanding of the history and current situation will help us more reasonably conduct research and promote cooperation.

Immune checkpoint inhibitors and cellular treatment for lymphoma immunotherapy

Malignant lymphoma (ML) is a common hematological malignancy with many subtypes. Patients with ML usually undergo traditional treatment failure and become relapsed or refractory (R/R) cases. Recently, immunotherapy, such as immune checkpoint inhibitors (ICIs) and cellular treatment, has gradually emerged and used in clinical trials with encouraging achievements for ML treatment, which exerts anti-tumor activity by blocking the immune evasion of tumor cells and enhancing the attack ability of immune cells. Targets of immune checkpoints include programmed cell death-1 (PD-1), programmed cell death-ligand 1 (PD-L1), cytotoxic T lymphocyte-associated protein 4 (CTLA-4), T cell immunoglobulin and ITIM domain (TIGIT), T cell immunoglobulin-3 (TIM-3) and lymphocyte activation gene 3 (LAG-3). Examples of cellular treatment are chimeric antigen receptor (CAR) T cells, cytokine-induced killer (CIK) cells and natural killer (NK) cells. This review aimed to present the current progress and future prospects of immunotherapy in lymphoma, with the focus upon ICIs and cellular treatment.

Efficacy and safety of chimeric antigen receptor T cell immunotherapy in B-cell non-Hodgkin lymphoma: a systematic review and meta-analysis

Aim: The aim was to evaluate the efficacy and safety of chimeric antigen receptor T (CAR-T) cell in B-cell non-Hodgkin lymphoma (B-NHL). Materials & methods: A meta-analysis was conducted using eligible clinical trials, which were obtained from electronic medical literature databases. Results: A total of 24 clinical trials with 590 patients were included. The best overall response rate was 66% and complete remission rate was 46%. The incidence rates of cytokine-release syndrome and neurotoxicity (grade ≥ 3) were 9 and 5%, respectively. The various clinical factors were analyzed. Autogenic CAR-T cell may lead to improved efficacy than allogeneic CAR-T cell. CD20 CAR-T cell may show increased efficacy than CD19 CAR-T cell. Conclusion: CAR-T immunotherapy has remarkable efficacy and low toxicity in relapsed/refractory B-NHL.

Current Progress in CAR-T Cell Therapy for Hematological Malignancies

Immunotherapies, such as monoclonal antibody therapy and checkpoint inhibitor therapy, have shown inspiring clinical effects for the treatment of cancer. Chimeric antigen receptor T (CAR-T) cells therapy was an efficacious therapeutic approach treating hematological malignancies and encouraging results have been achieved. Three kinds of CAR-T cell therapies, Kymriah (tisagenlecleucel), Yescarta (axicabtagene ciloleucel), were approved for clinical application in 2017 and Tecartus (brexucabtagene autoleucel) was approved in 2020. Despite some progress have been made in treating multiple hematologic tumors, threats still remain for the application of CAR-T cell therapy considering its toxicities and gaps in knowledge. To further comprehend present research status and trends, the review concentrates on CAR-T technologies, applications, adverse effects and safety measures about CAR-T cell therapy in hematological neoplasms. We believe that CAR-T cell therapy will exhibit superior safety and efficacy in the future and have potential to be a mainstream therapeutic choice for the elimination of hematologic tumor.

Immunotherapy of lymphomas

Lymphoid malignancies typically promote an infiltrate of immune cells at sites involved by the disease. While some of the immune cells present in lymphoma have effector function, the immune system is unable to eradicate the malignant clone. Therapies that optimize immune function therefore have the potential to improve the outcome of lymphoma patients. In this Review, we discuss immunologic approaches that directly target the malignant cell as well as approaches to optimize both the innate and adaptive immune response to the tumor. While many of these therapies have shown single-agent activity, the future will clearly require thoughtful combinations of these approaches.

Chimeric antigen receptor T cells for mature B-cell lymphoma and Burkitt lymphoma

Chimeric antigen receptor (CAR) T-cell therapy has changed the landscape of immunotherapy for B-cell malignancies, including mature B-cell lymphomas. Although two CD19 CAR T-cell products have been commercially approved to treat relapsed/refractory B-cell lymphomas, outcomes in these patients remain inferior to those of patients with B-cell leukemia, regardless of therapy. Recent clinical studies and preclinical reports suggest that certain characteristics, such as the suppressive lymphoma tumor microenvironment and inferior endogenous T-cell fitness, may contribute to discrepant responses in these patients. In addition, these studies revealed that limited CAR T-cell persistence and tumor antigen escape, which also impact B-cell acute lymphoblastic leukemia, may play a more prominent role in lymphoma. Multiple promising strategies to overcome these barriers have advanced to clinical trials. In this review, we assess CAR T-cell therapies for pediatric relapsed/refractory mature B-cell lymphomas, potential obstacles diminishing antitumor activity and limiting CAR T-cell persistence, and current strategies to overcome these obstacles.

PET/CT imaging for tumour response assessment to immunotherapy: current status and future directions

Recent immunotherapeutic approaches have evolved as powerful treatment options with high anti-tumour responses involving the patient's own immune system. Passive immunotherapy applies agents that enhance existing anti-tumour responses, such as antibodies against immune checkpoints. Active immunotherapy uses agents that direct the immune system to attack tumour cells by targeting tumour antigens. Active cellular-based therapies are on the rise, most notably chimeric antigen receptor T cell therapy, which redirects patient-derived T cells against tumour antigens. Approved treatments are available for a variety of solid malignancies including melanoma, lung cancer and haematologic diseases. These novel immune-related therapeutic approaches can be accompanied by new patterns of response and progression and immune-related side-effects that challenge established imaging-based response assessment criteria, such as Response Evaluation Criteria in Solid tumours (RECIST) 1.1. Hence, new criteria have been developed. Beyond morphological information of computed tomography (CT) and magnetic resonance imaging, positron emission tomography (PET) emerges as a comprehensive imaging modality by assessing (patho-)physiological processes such as glucose metabolism, which enables more comprehensive response assessment in oncological patients. We review the current concepts of response assessment to immunotherapy with particular emphasis on hybrid imaging with 18F-FDG-PET/CT and aims at describing future trends of immunotherapy and additional aspects of molecular imaging within the field of immunotherapy.

Efficacy and safety of second-generation CAR T-cell therapy in diffuse large B-cell lymphoma: A meta-analysis

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin's lymphoma (NHL), representing 30% of all lymphoma cases. Within the first 2-3 years following immunochemotherapy, 30-40% of patients will experience a relapse or a refractory disease, thereby exhibiting a poor prognosis. High-dose immunotherapy followed by autologous stem cell transplantation is the standard care for relapsed/refractory (RR) patients with DLBCL. However, >60% of patients are ineligible for a transplant, presenting a therapeutic challenge. Chimeric antigen receptor (CAR) T-cell therapy has shown promising efficacy in patients with DLBCL, including those with R/R disease. The present study conducted a meta-analysis that showed highly favorable outcomes [objective response rate (ORR): 69%; complete remission (CR): 49%] in B-cell NHL patients (n=419) who were treated with second-generation CAR T cells. The response rate varied in different types of B-cell NHL. In 306 patients with R/R DLBCL eligible for rate evaluation, the ORR and CR rate mean estimates were 68% [95% confidence interval (CI), 55-79%] and 46% (95% CI, 38-54%), respectively. Thus, the findings indicated that immunotherapy with CAR T cells has improved outcomes for patients with R/R DLBCL and other subtypes of B-cell NHL compared with standard chemotherapy regimens. The study revealed that grade ≥3 anemia (34%) and thrombocytopenia (30%) were the most common adverse effects of CAR T-cell therapy. Incidence of grade ≥3 cytokine release syndrome and neurotoxicity associated with CAR T-cell therapy was effectively managed.

Chimeric antigen receptor T-cell therapy beyond cancer: current practice and future prospects

Adoptive cell therapy with chimeric antigen receptor T (CAR-T) cells has achieved remarkable efficacy in the treatment of hematological malignancies, which has inspired researchers to expand the application of CAR-T-cell therapy to other medical conditions. Here, we review the current understanding and development of CAR-T-cell therapy for infectious diseases, autoimmune diseases and allotransplantation. The limitations and challenges of CAR-T-cell therapy in the treatment of these diseases and potential solutions to overcome these shortcomings are also discussed. With the development of novel designs of CARs and preclinical/clinical investigations, CAR-T-cell therapy is expected to be a potential cure option in a wide array of disease settings in the future.