Anti-CD 19 and anti-CD 20 CAR-modified T cells for B-cell malignancies: a systematic review and meta-analysis

CAR T-Cells in Acute Lymphoblastic Leukemia: Current Status and Future Prospects

The currently available treatment for acute lymphoblastic leukemia (ALL) is mainly dependent on the combination of chemotherapy, steroids, and allogeneic stem cell transplantation. However, refractoriness and relapse (R/R) after initial complete remission may reach up to 20% in pediatrics. This percentage may even reach 60% in adults. To overcome R/R, a new therapeutic approach was developed using what is called chimeric antigen receptor-modified (CAR) T-cell therapy. The Food and Drug Administration (FDA) in the United States has so far approved four CAR T-cells for the treatment of ALL. Using this new therapeutic strategy has shown a remarkable success in treating R/R ALL. However, the use of CAR T-cells is expensive, has many imitations, and is associated with some adverse effects. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are two common examples of these adverse effects. Moreover, R/R to CAR T-cell therapy can take place during treatment. Continuous development of this therapeutic strategy is ongoing to overcome these limitations and adverse effects. The present article overviews the use of CAR T-cell in the treatment of ALL, summarizing the results of relevant clinical trials and discussing future prospects intended to improve the efficacy of this therapeutic strategy and overcome its limitations.

Effectiveness and safety of CD22 and CD19 dual-targeting chimeric antigen receptor T-cell therapy in patients with relapsed or refractory B-cell malignancies: A meta-analysis

BACKGROUND

The efficacy of CD22 or CD19 chimeric antigen receptor T (CAR-T) cells in the management of acute lymphoblastic leukemia (ALL) and non-Hodgkin lymphoma (NHL) was observed. Because antigen loss and lack of CAR-T-cell persistence are the leading causes of progressive disease following single-antigen targeting, we evaluated CD22/CD19 dual-targeting CAR-T-cell therapy efficacy and safety in relapsed/refractory B-cell malignancies.

METHODS

The Web of Science, PubMed, Cochrane, and Embase databases were searched until July 2022. Patients confirmed with any relapsed/refractory B-cell hematological malignancies were included regardless of age, gender, or ethnicity, receiving CD22 and CD19-dual-targeting CAR-T-cell therapy. The studies conducted on patients with coexisting other cancer were excluded. We used random-effect models to explore the outcome, and heterogeneity was investigated by subgroup analysis.

RESULTS

Fourteen studies (405 patients) were included. The pooled overall response (OR) and complete remission (CR) were 97% and 93%, respectively, for ALL patients. The 1-year proportions of overall survival (OS) and progression-free survival (PFS) were 70% and 49%, respectively. For NHL, OR occurred in 85% of patients, and 57% experienced CR. The results illustrated that the 1-year OS and 1-year PFS were 77% and 65%, respectively. The subgroup analysis showed that the dual-targeting modality achieved higher CR in the following cases: coadministration of CD22/CD19-CAR-T cells and third-generation CAR-T cells combined with ASCT and BEAM pretreatment. The ALL and NHL groups seemed similar in treatment-related toxicity: all grade cytokine release syndrome (CRS), severe CRS, and neurotoxicity occurred in 86%, 7%, and 12% of patients, respectively.

CONCLUSIONS

Our meta-analysis demonstrated that the CD22/CD19 dual-targeting CAR-T-cell strategy has high efficiency with tolerable adverse effects in B-cell malignancies.

Chimeric antigen receptor T (CAR-T) cells: Novel cell therapy for hematological malignancies

Over the last decade, the emergence of several novel therapeutic approaches has changed the therapeutic perspective of human malignancies. Adoptive immunotherapy through chimeric antigen receptor T cell (CAR-T), which includes the engineering of T cells to recognize tumor-specific membrane antigens and, as a result, death of cancer cells, has created various clinical benefits for the treatment of several human malignancies. In particular, CAR-T-cell-based immunotherapy is known as a critical approach for the treatment of patients with hematological malignancies such as acute lymphoblastic leukemia (ALL), multiple myeloma (MM), chronic lymphocytic leukemia (CLL), acute myeloid leukemia (AML), Hodgkin lymphoma (HL), and non-Hodgkin's lymphoma (NHL). However, CAR-T-cell therapy of hematological malignancies is associated with various side effects. There are still extensive challenges in association with further progress of this therapeutic approach, from manufacturing and engineering issues to limitations of applications and serious toxicities. Therefore, further studies are required to enhance efficacy and minimize adverse events. In the current review, we summarize the development of CAR-T-cell-based immunotherapy and current clinical antitumor applications to treat hematological malignancies. Furthermore, we will mention the current advantages, disadvantages, challenges, and therapeutic limitations of CAR-T-cell therapy.

Lessons to cancer from studies of leukemia and hematopoiesis

The starting point to describing the origin and nature of any cancer must be knowledge about how the normal counterpart tissue develops. New principles to the nature of hematopoietic stem cells have arisen in recent years. In particular, hematopoietic stem cells can “choose” a cell lineage directly from a spectrum of the end-cell options, and are, therefore, a heterogeneous population of lineage affiliated/biased cells. These cells remain versatile because the developmental trajectories of hematopoietic stem and progenitor cells are broad. From studies of human acute myeloid leukemia, leukemia is also a hierarchy of maturing or partially maturing cells that are sustained by leukemia stem cells at the apex. This cellular hierarchy model has been extended to a wide variety of human solid tumors, by the identification of cancer stem cells, and is termed the cancer stem cell model. At least, two genomic insults are needed for cancer, as seen from studies of human childhood acute lymphoblastic leukemia. There are signature mutations for some leukemia’s and some relate to a transcription factor that guides the cell lineage of developing hematopoietic stem/progenitor cells. Similarly, some oncogenes restrict the fate of leukemia stem cells and their offspring to a single maturation pathway. In this case, a loss of intrinsic stem cell versatility seems to be a property of leukemia stem cells. To provide more effective cures for leukemia, there is the need to find ways to eliminate leukemia stem cells.

Adoptive cell therapies in thoracic malignancies

Immunotherapy has gained great interest in thoracic malignancies in the last decade, first in non-small cell lung cancer (NSCLC), but also more recently in small-cell lung cancer (SCLC) and malignant pleural mesothelioma (MPM). However, while 15-20% of patients will greatly benefit from immune checkpoint blockers (ICBs), a vast majority will rapidly exhibit resistance. Reasons for this are multiple: non-immunogenic tumors, immunosuppressive tumor microenvironment or defects in immune cells trafficking to the tumor sites being some of the most frequent. Current progress in adoptive cell therapies could offer a way to overcome these hurdles and bring effective immune cells to the tumor site. In this review, we discuss advantages, limits and future perspectives of adoptive cell therapy (ACT) in thoracic malignancies from lymphokine-activated killer cells (LAK), cytokine-induced killer cells (CIK), natural killer cells (NK), dendritic cells (DC) vaccines and tumor-infiltrating lymphocytes (TILs) to TCR engineering and CARs. Trials are still in their early phases, and while there may still be many limitations to overcome, a combination of these different approaches with ICBs, chemotherapy and/or radiotherapy could vastly improve the way we treat thoracic cancers.

Use of CAR T-cell for acute lymphoblastic leukemia (ALL) treatment: a review study

Acute lymphoblastic leukemia (ALL) is a cancer-specific lymphoid cell. Induction and consolidation chemotherapy alone or in combination with different therapeutic approaches remain the main treatment. Although complete or partial remission of the disease can be achieved, the risk of relapse or refractory leukemia is still high. More effective and safe therapy options are yet unmet needs. In recent years' new therapeutic approaches have been widely used. Hematopoietic Stem Cell Transplantation (HSCT) presents significant limitations and the outcome of the consolidation treatment is patient dependent. Side effects such as Graft versus Host Disease (GvHD) in allogeneic hematopoietic stem cell transplantation are extremely common, therefore, using alternative methods to address these challenges for treatment seems crucial. In the last decade, T cells genetically engineered with Chimeric Antigen Receptor (CAR) treatment for the ALL are largely studied and represent the new era of strategy. According to the Phase I/II clinical trials, this technology results seem very promising and can be used in the next future as an effective and safe treatment for ALL treatment. In this review different generations, challenges, and clinical studies related to chimeric antigen receptor (CAR) T-cells for ALL treatment are discussed.

Efficacy and safety of CD22 chimeric antigen receptor (CAR) T cell therapy in patients with B cell malignancies: a protocol for a systematic review and meta-analysis

BACKGROUND

Chimeric antigen receptor (CAR) T cell therapy has had great success in treating patients with relapsed or refractory B cell malignancies, with CD19-targeting therapies now approved in many countries. However, a subset of patients fails to respond or relapse after CD19 CAR T cell therapy, in part due to antigen loss, which has prompted the search for alternative antigen targets. CD22 is another antigen found on the surface of B cells. CARs targeting CD22 alone or in combination with other antigens have been investigated in several pre-clinical and clinical trials. Given the heterogeneity and small size of CAR T cell therapy clinical trials, systematic reviews are needed to evaluate their efficacy and safety. Here, we propose a systematic review of CAR T cell therapies targeting CD22, alone or in combination with other antigen targets, in B cell malignancies.

METHODS

We will perform a systematic search of EMBASE, MEDLINE, Web of Science, Cochrane Register of Controlled Trials, clinicaltrials.gov, and the International Clinical Trials Registry Platform. Ongoing and completed clinical trials will be identified and cataloged. Interventional studies investigating CD22 CAR T cells, including various multi-antigen targeting approaches, in patients with relapsed or refractory B cell malignancies will be eligible for inclusion. Only full-text articles, conference abstracts, letters, and case reports will be considered. Our primary outcome will be a complete response, defined as absence of detectable cancer. Secondary outcomes will include adverse events, overall response, minimal residual disease, and relapse, among others. Quality assessment will be performed using a modified Institute of Health Economics tool designed for interventional single-arm studies. We will report a narrative synthesis of clinical studies, presented in tabular format. If appropriate, a meta-analysis will be performed using a random effects model to synthesize results.

DISCUSSION

The results of the proposed review will help inform clinicians, patients, and other stakeholders of the risks and benefits of CD22 CAR T cell therapies. It will identify gaps or inconsistencies in outcome reporting and help to guide future clinical trials investigating CAR T cells.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42020193027.

Mesothelin-targeted CAR-T cells for adoptive cell therapy of solid tumors

Significant progresses have been made in adoptive cell therapy with CAR-T cells for cancers, especially for hematological malignancies. However, the treatment of solid tumors still poses a tremendous challenge and remains an unmet medical need. Several factors are held responsible for the inadequate responses: tumor heterogeneity, inefficient homing of T cells to tumor tissues, immunosuppressive microenvironment and the shortage of specific antigens shortage. Mesothelin is a cell-surface glycoprotein highly expressed in many types of solid tumors. As such, it has attracted much attention as a molecular target in cancer immunotherapy. Here, we delineate the barriers imposed by solid tumors on CARs, outline the rationale of mesothelin as a target for immunotherapy, summarize the preclinical and clinical results of mesothelin-targeted therapies, and extrapolate the expected results of CAR-T cells directed against mesothelin for solid tumors.

Skin-Associated B Cells in the Pathogenesis of Cutaneous Autoimmune Diseases-Implications for Therapeutic Approaches

B lymphocytes are crucial mediators of systemic immune responses and are known to be substantial in the pathogenesis of autoimmune diseases with cutaneous manifestations. Amongst them are lupus erythematosus, dermatomyositis, systemic sclerosis and psoriasis, and particularly those driven by autoantibodies such as pemphigus and pemphigoid. However, the concept of autoreactive skin-associated B cells, which may reside in the skin and locally contribute to chronic inflammation, is gradually evolving. These cells are believed to differ from B cells of primary and secondary lymphoid organs and may provide additional features besides autoantibody production, including cytokine expression and crosstalk to autoreactive T cells in an antigen-presenting manner. In chronically inflamed skin, B cells may appear in tertiary lymphoid structures. Those abnormal lymph node-like structures comprise a network of immune and stromal cells possibly enriched by vascular structures and thus constitute an ideal niche for local autoimmune responses. In this review, we describe current considerations of different B cell subsets and their assumed role in skin autoimmunity. Moreover, we discuss traditional and B cell-associated approaches for the treatment of autoimmune skin diseases, including drugs targeting B cells (e.g., CD19- and CD20-antibodies), plasma cells (e.g., proteasome inhibitors, CXCR4 antagonists), activated pathways (such as BTK- and PI3K-inhibitors) and associated activator molecules (BLyS, APRIL).

Uncovering the Exosomes Diversity: A Window of Opportunity for Tumor Progression Monitoring

Cells can communicate through special “messages in the bottle”, which are recorded in the bloodstream inside vesicles, namely exosomes. The exosomes are nanovesicles of 30–100 nm in diameter that carry functionally active biological material, such as proteins, messanger RNA (mRNAs), and micro RNA (miRNAs). Therefore, they are able to transfer specific signals from a parental cell of origin to the surrounding cells in the microenvironment and to distant organs through the circulatory and lymphatic stream. More and more interest is rising for the pathological role of exosomes produced by cancer cells and for their potential use in tumor monitoring and patient follow up. In particular, the exosomes could be an appropriate index of proliferation and cancer cell communication for monitoring the minimal residual disease, which cannot be easily detectable by common diagnostic and monitoring techniques. The lack of unequivocal markers for tumor-derived exosomes calls for new strategies for exosomes profile characterization aimed at the adoption of exosomes as an official tumor biomarker for tumor progression monitoring.

Efficacy and safety of humanized anti-CD19-CAR-T therapy following intensive lymphodepleting chemotherapy for refractory/relapsed B acute lymphoblastic leukaemia

We studied the efficacy and safety of humanized CAR-T therapy following intensive chemotherapy for refractory/relapsed (R/R) acute lymphoblastic leukaemia (B-ALL). Twenty-three patients with R/R B-ALL were pretreated with intensive chemotherapy (fludarabine combined with medium-dose cytarabine) 12 days before CAR-T therapy. Adverse events (AEs), curative effects, infection indicators and cytokine release syndrome (CRS) were monitored. Each of the 23 patients received a dose of 1·0 × 10⁶ cells/kg CAR-T cell infusion on day 0. After 14 days, 19 patients (82·61%) achieved complete response (CR) or CR with incomplete count recovery. No survival benefit was achieved with consolidative haematopoietic stem-cell transplantation (HSCT), with a median follow-up of 14·0 months (range, 1·5-21·0 months). The notable AEs were grade 1-2 CRS in 18 patients, while the other five patients were grade 3 CRS. No patients died of CRS. Only one patient died of respiratory failure due to cytomegalovirus infection 24 days after infusion. The proportion of leukaemic cells in bone marrow on infusion day and the peaks of IL-6, TNF-α and IL-8 levels were correlated with CRS levels. A lower disease burden was achieved by intensive lymphodepleting chemotherapy, and the subsequent CAR-T therapy had a high response and manageable toxicity. Trial registration: The patients were enrolled in a clinical trial of ChiCTR-ONN-16009862, and ChiCTR1800019622.

Efficacy and safety of chimeric antigen receptor-T cells in the treatment of B cell lymphoma: a systematic review and meta-analysis

BACKGROUND

Conventional treatment has limited efficacy in relapsed/refractory B-cell lymphoma. Since chimeric antigen receptor T-cell (CAR-T) technology has shown high safety and results in high remission rates, we investigated its efficacy and safety in B-cell lymphoma treatment and analyzed potential affecting factors to provide evidence for therapeutic strategies and applications.

METHODS

We searched databases including PubMed, Embase, and Cochrane up to July 2019. Meta-analysis 1 was conducted to study the efficacy of CAR-T cell for treating B-cell lymphoma, measuring the response rate and complete remission rate as outcomes. Sub-group analysis was performed for age, pathological type, target antigen, co-stimulatory molecule, and conditioning chemotherapy. Meta-analysis 2 was undertaken on the safety of the treatment with the incidence rate of toxicity (cytokine-releasing syndrome [CRS], neurotoxicity) as an outcome.

RESULTS

Seventeen studies were included in the systematic review and meta-analysis. It was found that CAR-T cells had good therapeutic effects in the following cases: B-cell lymphoma (patients ≥65 years old); diffuse large B-cell lymphoma pathological type; patients with treatment target antigen other than CD19; patients treated with co-stimulatory molecules other than CD28, including 4-1BB+CD28 or 4-1BB; and patients treated with cyclophosphamide/fludarabine pre-treatment protocol conditioning chemotherapy. Although the CRS and neurotoxicity incidences were high, most were reversible with minimal risk of death.

CONCLUSION

CAR-T cell treatment is safe for clinical application; however, toxicity effects should be monitored.

Diagnosis and Management of Immune Related Adverse Events (irAEs) in Cancer Immunotherapy

Immune checkpoint inhibitors (ICPIs) and chimeric antigen receptor (CAR) T-cell therapy are two main promising methods of immunotherapy, which have become increasingly important in cancer treatment. After the wider application of these medicine in clinic, a range of immune related adverse events (irAEs) covering almost any system arouse the concern for being randomness and unpredictability. Even if most adverse events are mild and controllable after thoughtful management, the occurrence of life-threatening toxicities should not be ignored because of the insidious and atypical symptoms, which makes the early diagnosis even more challenging. In this review, a brief introduction of immunotherapy and mechanisms underlying irAEs is involved. We mainly focus on the early diagnostic method and recommended management of toxicities of different systems separately, and consequently maximized effectiveness of immunotherapy can be achieved.

Efficiency and safety of autologous chimeric antigen receptor T-cells therapy used for patients with lymphoma: A systematic review and meta-analysis

BACKGROUND

Chimeric antigen receptor (CAR) T-cell therapy has produced promising response rates in patients with B cell malignancies. However, previous meta-analyses have demonstrated that CAR T-cell efficacy is unsatisfactory in patients with lymphoma unlike in patient with other hematological malignancies, but these studies included insufficient numbers of studies and patients with lymphoma. Furthermore, clinicians are interested in the effects of infusion dose, CAR structure, interleukin-2 (IL-2), and conditioning therapy regimen.

METHODS

All clinical trials administering autologous CAR T-cell therapy in lymphoma patients were searched in medical databases. A traditional meta-analysis was performed to assess the safety and efficacy of CAR T-cells in lymphoma treatment. Subgroup analysis was performed to determine the relationships between potential factors and efficacy. The best overall response rate (ORR), 6 month ORR (6m ORR), and severe cytokine release syndrome (sCRS) rate were calculated by Stata 14.0.

RESULTS

A total of 411 patients across all the studies were included. Our analysis showed a best ORR of 0.71, a 6m ORR of 0.63, and an overall CRS (grade ≥ 3) rate of 0.18. The subgroup analysis showed that increased response rates and reduced CRS (grade ≥ 3) rates were associated with a low dose of CAR T-cells. No IL-2 administration and the use of a fludarabine-containing lymphodepletion regimen led to improved efficacy, while anti-CD19 CAR T cells led to a more successful outcome than anti-CD20 CAR T cells. In addition, 2nd- and 3rd-generation CAR T cells exhibited increased effectiveness in clinical studies, and no significant effect diversity was found between the 2nd- and 3rd-generation CAR T cells. sCRS was associated with a high dose of infused CAR T cells when IL-2 and fludarabine were excluded from the positive factors for sCRS.

CONCLUSION

CAR T cells are promising in the treatment of relapsed or refractory lymphoma. Doses lower than 10/m, no IL-2 administration, fludarabine administration, and anti-CD19 CAR T cells were related to improved efficacy and safety.

Histopathologic Analysis of Conjunctival Lymphoproliferative Disease After Topical Brimonidine Use

Purpose: To describe of histopathological findings of conjunctival lymphoproliferative disease (CLD) after topical brimonidine use. Methods: This is a retrospective medical record review study, including histopathologic description. We reviewed the medical records of 208 patients (415 eyes) who were diagnosed with glaucoma and who were treated with topical brimonidine only for a minimum of 6 months. Of these, the medical records of 19 patients with suspected CLD clinical features were reviewed in detail. When CLD was suspected due to administration of brimonidine, histopathological analysis was performed by biopsy of these lesions. In addition, immunohistochemical staining was performed to analyze lymphocyte markers in some pathological tissues. Results: Nineteen patients had suspected CLD without definite irritative symptoms. Diffuse elevated (11 patients) or follicular lesion (8 patients) of salmon pink appearance was observed in inferior palpebral conjunctiva. Among these patients, 5 patients who agreed to conjunctival biopsy had histopathological findings of CLD such as reactive lymphoid hyperplasia (LH) (2 cases) or atypical LH (2 cases). The mean duration of brimonidine use was 29.00 ± 20.25 months (6-76 months). And follow-up period after discontinuation of brimonidine was 27.93 ± 11.87 months (12-58 months). At the last visit, complete resolution of the lesion was seen in 13 patients, and partial improvement was observed in 6 patients. Conclusions: We found 4 cases of CLD following long-term administration of brimonidine. However, large-scale additional studies should be performed to establish causality, to determine whether these novel side effects were caused by long-term brimonidine treatment.

Current status and future prospects of the strategy of combining CAR‑T with PD‑1 blockade for antitumor therapy (Review)

The immune system serves an important role in controlling and eradicating malignant cells. Immunotherapy for treating tumors has received much attention in recent years due to its marked effect. There are two approaches which currently lead this field: Chimeric antigen receptor‑modified T‑cell immunotherapy (CAR‑T) and programmed cell death protein-1 blockade (PD‑1 blockade). CAR‑T has emerged as a promising regimen for the treatment of a range of types of cancer, including chronic lymphoid leukemia and neuroblastoma, with studies of long term remission in certain patients. PD‑1 blockade has been reported to exert marked clinical responses in patients against a range of types of solid cancer, including advanced melanoma, non‑small‑cell lung cancer and renal cell carcinoma, in addition to hematological malignancies. While increasing the power of the immune system to fight cancer has been a long‑standing goal in oncology, a number of studies have demonstrated the synergistic antitumor effects of combination therapies under the umbrella of immunotherapy. The present review focused on a novel combination approach involving CAR‑T and PD‑1 blockade. The present reviews aimed to discuss the following four aspects of such an approach: i) Current monotherapy status; ii) rationale for the combination of CAR‑T and PD‑1 blockade; iii) current status of the combination of CAR‑T and PD‑1 blockade; and iv) conclusions and future perspectives.