T-Cell Engineering For “off-The-shelf” Adoptive Immunotherapy

Abstract

Adoptive T-cell therapies, where exogenous expression of a chimeric antigen receptor (CAR) confers cancer recognition, have shown significant promise in initial clinical trials. However, present adoptive immunotherapy Methods are limited by the need for manipulation of autologous patient T-cells. To permit such an approach in an allogeneic context, Transcription Activator-Like Effector Nucleases (TALENTM) have been used to simultaneously inactivate the endogenous T cell receptor and CD52, a cellular target for a lymphodepleting treatment. This approach reduces the risk of GVHD while permitting proliferation and activity of the introduced T lymphocytes in the presence of the immunosuppressive drug alemtuzumab. Electroporation of primary T cells with mRNA coding for the appropriate TALENTM result in double knock-out (dKO) frequencies of up to 70%. Furthermore, functional characterization demonstrates that the dKO cells are resistant to complement dependent lysis or in vivo depletion by alemtuzumab, and show no apparent potential for TCR-mediated activation. Finally, endowing the dKO cells with a CD19 CAR supports their capacity to kill CD19+ tumor targets as efficiently as unedited T-cells both in vitro and in vivo. Disclosures: Poirot: CELLECTIS THERAPEUTICS: Employment. Schiffer-Mannioui:CELLECTIS THERAPEUTICS: Employment. Philip:UCL Cancer Institute, London, United Kingdom: Employment. Derniame:CELLECTIS THERAPEUTICS: Employment. Gouble:CELLECTIS THERAPEUTICS: Employment. Chion-Sotinel:CELLECTIS THERAPEUTICS: Employment. Le Clerre:CELLECTIS THERAPEUTICS: Employment. Lemaire:CELLECTIS THERAPEUTICS: Employment. Grosse:CELLECTIS THERAPEUTICS: Employment. Cheung:UCL Cancer Institute, London, United Kingdom: Employment. Arnould:CELLECTIS THERAPEUTICS: Employment. Smith:CELLECTIS THERAPEUTICS: Employment. Pule:UCL Cancer Institute, London, United Kingdom: Employment. Scharenberg:CELLECTIS THERAPEUTICS: Employment.

Clinical Pharmacology and Determinants of Response to UCART19, an Allogeneic Anti-CD19 CAR-T Cell Product, in Adult B-cell Acute Lymphoblastic Leukemia

“…Elimination of TRAC prevents GvHD, while the CD52 gene knock-out protects donor cells from early rejection through alemtuzumab, a powerful anti-CD52 peripheral lymphodepleting agent (13). We recently demonstrated the feasibility of administering UCART19 to adult and pediatric patients diagnosed with R/R B-ALL (14,15).…”

The current landscape of CAR T-cell therapy for solid tumors: Mechanisms, research progress, challenges, and counterstrategies

“…However, increasing the complexity of CAR designs and editing the genes on T-cells may increase the risks associated with CAR T-cell therapy. For instance, the use of gene-editing tools and viral transduction both carry the risk of off-target disruption of genes (299). Indeed, a well-anticipated theoretical danger of any gene therapy is the transformation of T-cells into malignant clones due to insertional mutagenesis involving either activation of endogenous protooncogenes by viral promoters or loss of tumor-suppressor genes (244).…”

Genetic engineering strategies to enhance antitumor reactivity and reduce alloreactivity for allogeneic cell-based cancer therapy

“…Lymphodepletion is a crucial step in cell therapies to reduce suppressive immune cells and decrease immunogenicity of the host immune system prior to cell transfer. One method for temporary lymphodepletion is to use alemtuzumab, a monoclonal antibody that targets CD52 and induces ADCC against mature lymphocytes but not naïve lymphocyte progenitors (165); however, this method cannot be used for adoptive transfer due to indiscriminate targeting of healthy and cancerous lymphocytes (165). One genetic engineering approach to address this challenge is the disruption of CD52 expression with TALEN mRNA to eliminate the binding cite of alemtuzumab in order to maintain antitumor efficacy.…”