Real-time transfer of lentiviral particles by producer cells using an engineered coculture system

Manufacturing Cell and Gene Therapies: Challenges in Clinical Translation

The safety and efficacy of both cell and gene therapies have been demonstrated in numerous preclinical and clinical trials. Chimeric antigen receptor T (CAR-T) cell therapy, which leverages the technologies of both cell and gene therapies, has also shown great promise for treating various cancers. Advancements in pertinent fields have also highlighted challenges faced while manufacturing cell and gene therapy products. Potential problems and obstacles must be addressed to ease the clinical translation of individual therapies. Literature reviews of representative cell-based, gene-based, and cell-based gene therapies with regard to their general manufacturing processes, the challenges faced during manufacturing, and QC specifications are limited. We review the general manufacturing processes of cell and gene therapies, including those involving mesenchymal stem cells, viral vectors, and CAR-T cells. The complexities associated with the manufacturing processes and subsequent QC/validation processes may present challenges that could impede the clinical progression of the products. This article addresses these potential challenges. Further, we discuss the use of the manufacturing model and its impact on cell and gene therapy.

Recent advances in the production, reprogramming, and application of CAR-T cells for treating hematological malignancies

As genetically engineered cells, chimeric antigen receptor (CAR)-T cells express specific receptors on their surface to target and eliminate malignant cells. CAR proteins are equipped with elements that enhance the activity and survival of T cells. Once injected, CAR-T cells act as a "living drug" against tumor cells in the body. Up to now, CAR-T cell therapy has been demonstrated as a robust adoptive cell transfer (ACT) immunotherapeutic modality for eliminating tumor cells in refractory hematological malignancies. CAR-T cell therapy modality involves several steps, including the collecting of the blood from patients, the isolation of peripheral blood mononuclear cells (PBMCs), the enrichment of CD4⁺/CD8⁺ T cell, the genetic reprogramming, the expansion of modified T cells, and the injection of genetically engineered T cells. The production of CAR-T cells is a multi-step procedure, which needs precise and safety management systems, including good manufacturing practice (GMP), and in-line quality control and assurance. The current study describes the structure of CARs and concentrates on the next generations of CARs that are engaged in enhancing the anti-tumor responses and safety of the engineered T cells. This paper also highlights the important concerns in quality control and nonclinical research of CAR-T cells, as well as general insights into the manufacture, reprogramming, and application of CAR-T cells based on new and enhanced techniques for treating hematological malignancies. Besides, the application of the CRISPR-Cas9 genome editing technology and nanocarrier-based delivery systems containing CAR coding sequences to overcome the limitations of CAR-T cell therapy has also been explained.

CD19/CD22 Dual-Targeted CAR T-cell Therapy for Relapsed/Refractory Aggressive B-cell Lymphoma: A Safety and Efficacy Study

Chimeric antigen receptor (CAR) T-cell therapies that target either CD19 or CD22 alone have potent antilymphoma effects. However, antigen escape-mediated relapse often occurs. CAR T cells targeting both CD19 and CD22 may overcome this limitation. In this study, we developed bispecific CAR T cells simultaneously recognizing CD19- and CD22-expressing targets and assessed their safety and efficacy profiles in patients with relapsed/refractory aggressive B-cell lymphoma. Twenty-four patients were screened, and 16 were found eligible for the study. CAR T-cell-associated toxicities were recorded. Responses, overall survival (OS), and progression-free survival (PFS) were assessed. Of the 16 eligible patients, 14 (87.5%) achieved objective response and 10 (62.5%) achieved complete response (CR). The 2-year OS and PFS rates were 77.3% and 40.2%, respectively. Achieving CR (P = 0.046) and the number of prior chemotherapy lines (n = 2; P = 0.047) were independent prognostic factors associated with favorable PFS. The 2-year OS and PFS among patients who achieved CR were higher than among those who did not (P = 0.015 and P < 0.001, respectively). The 2-year PFS among patients who received two prior lines of chemotherapy was higher than that among patients who received more than two lines of chemotherapy (P = 0.049); OS did not differ between the groups. Severe grade 4 cytokine-release syndrome (CRS) was observed in 1 patient; 4 and 11 patients had grades 1 and 2 CRS, respectively. No patients developed neurotoxicity. CD19/CD22 dual-targeted CAR T cells may be a safe, potent antilymphoma cell-based targeted immunotherapy.