Adoptive Immunotherapy for B-cell Malignancies Using CD19- Targeted Chimeric Antigen Receptor T-Cells: A Systematic Review of Efficacy and Safety

Therapeutic efficacy and infectious complications of CD19-targeted chimeric antigen receptor-modified T cell immunotherapy

Lymphocyte depletion chemotherapy CD19-targeted chimeric antigen receptor-modified T (CAR-T) cell immunotherapy is an innovative approach for the treatment of refractory or relapsed B-cell malignancies. This method also has the occurrence of infection, and there has been no systematic analysis of infectious complications. In our study, we intend to analyze the infection in patients between day 0 and day 90 by analyzing the data of 40 patients who received CD19 CAR-T cell therapy collected in our hospital. We assessed risk factors for infection before and after treatment using Poisson and Cox regression, respectively. A cohort study was used, including patients with acute lymphocytic leukemia, chronic lymphocytic leukemia and non-Hodgkin's lymphoma. 40 patients were infected for the first time occurred at a median of 6 days after CAR-T cell infusion, and 8 (20%) had 10 infections within 28 days after CAR-T cell infusion, on days 29 and 29. The infection density between 90 days was lower at 0.67. This resulted in an infection density of 1.19 infections per 100 days. Two patients (5%) developed invasive fungal infections and two patients (5%) developed life-threatening or fatal infections. In an adjusted model for baseline characteristics, patients with ALL, ≥4 prior antitumor regimens, and receiving the highest CAR-T cell dose had higher infection densities at 28 days. The incidence of infection was comparable to that observed in clinical trials of salvage associated with infection after CAR-T cell infusion.

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.

The incidence of cytokine release syndrome and neurotoxicity of CD19 chimeric antigen receptor-T cell therapy in the patient with acute lymphoblastic leukemia and lymphoma

Our objective was to summarize the side effect of chimeric antigen receptor (CAR)-T cell therapy in patients with acute lymphocytic leukemia (ALL) and lymphoma. Two independent reviewers extracted relevant data. A total of 35 hematologic malignancy studies with CD19 CAR-T cell were included (1412 participants). Severe cytokine release syndrome (sCRS) proportion was experienced by 18.5% (95% confidence interval [CI], 0.128-0.259; P = 0.000) of 982 patients with the National Cancer Institute/Lee/common terminology criteria for adverse events grading system. The pooled neurotoxicity proportion was 21.7% (95% CI, 0.167-0.287; P = 0.000) of 747 patients with the same grading system. For all of the 25 clinical trials with the same grading system, subgroup analysis was performed. Based on the different disease type, a pooled prevalence of 35.7% was observed with event rate (ER) of 0.358 (95% CI, 0.289-0.434; P = 0.000) for ALL in 12 clinical trials. For lymphoma, a pooled prevalence of 13% was observed with ER of 0.073 (95% CI, 0.028-0.179; P = 0.000) in eight clinical trials. It was demonstrated that the patients who were older than 18 years of age have the lower sCRS incidence of 16.1% (95% CI, 0.110-0.250; P = 0.000) compared with 28.6% of the remaining population who were younger than 18 years of age (95% CI, 0.117-0.462: P = 0.023) in our analysis. Based on the different co-stimulatory domain, the sCRS of 16.5% was observed with ER of 0.175 (95% CI, 0.090-0.312; P = 0.000) for 4-1BB. The sCRS of 22.2% was observed with ER of 0.193 (95% CI, 0.107-0.322; P = 0.000) for CD28. For both the CD28 and 4-1BB, the sCRS of 17.3% was observed with ER of 0.170 (95% CI, 0.067-0.369; P = 0.003). Sub-analysis sCRS of the impact with cell dose and specific disease indication were also demonstrated. Limitations include heterogeneity of study populations, as well as high risk of bias of included studies. These results are helpful for physicians, patients and the other stakeholders to understand the adverse events and to further promote the improvement of CAR-T cell therapy in the future.

Automated Manufacture of Autologous CD19 CAR-T Cells for Treatment of Non-hodgkin Lymphoma

Chimeric antigen receptor T cells (CAR-T cell) targeting CD19 are effective against several subtypes of CD19-expressing hematologic malignancies. Centralized manufacturing has allowed rapid expansion of this cellular therapy, but it may be associated with treatment delays due to the required logistics. We hypothesized that point of care manufacturing of CAR-T cells on the automated CliniMACS Prodigy® device allows reproducible and fast delivery of cells for the treatment of patients with non-Hodgkin lymphoma. Here we describe cell manufacturing results and characterize the phenotype and effector function of CAR-T cells used in a phase I/II study. We utilized a lentiviral vector delivering a second-generation CD19 CAR construct with 4-1BB costimulatory domain and TNFRSF19 transmembrane domain. Our data highlight the successful generation of CAR-T cells at numbers sufficient for all patients treated, a shortened duration of production from 12 to 8 days followed by fresh infusion into patients, and the detection of CAR-T cells in patient circulation up to 1-year post-infusion.

Sequential allogeneic and autologous CAR-T-cell therapy to treat an immune-compromised leukemic patient

CAR-T–cell therapy normally requires the patient’s own healthy T cells. An allogeneic CAR-T bridging therapy could rescue lymphopenic patients.