Efficacy and safety of universal (TCRKO) ARI-0001 CAR-T cells for the treatment of B-cell lymphoma Maldonado Pérez, Noelia Tristán Manzano, María Justicia Lirio, Pedro Martínez Planes, Elena Muñoz, Pilar Pavlovic, Kristina Cortijo Gutiérrez, Marina Blanco Benítez, Carlos Molina Estévez, Francisco Javier Marañón, Concepción Benabdellah, Karim Martín Molina, Francisco CAR-T cells Lymphoma TCRKO CRISPR/Cas9 Off-the-shelf Safety Large deletions Autologous T cells expressing the Chimeric Antigen Receptor (CAR) have been approved as advanced therapy medicinal products (ATMPs) against several hematological malignancies. However, the generation of patient-specific CART products delays treatment and precludes standardization. Allogeneic off-theshelf CAR-T cells are an alternative to simplify this complex and timeconsuming process. Here we investigated safety and efficacy of knocking out the TCR molecule in ARI-0001 CAR-T cells, a second generation aCD19 CAR approved by the Spanish Agency of Medicines and Medical Devices (AEMPS) under the Hospital Exemption for treatment of patients older than 25 years with Relapsed/Refractory acute B cell lymphoblastic leukemia (B-ALL). We first analyzed the efficacy and safety issues that arise during disruption of the TCR gene using CRISPR/Cas9. We have shown that edition of TRAC locus in T cells using CRISPR as ribonuleorproteins allows a highly efficient TCR disruption (over 80%) without significant alterations on T cells phenotype and with an increased percentage of energetic mitochondria. However, we also found that efficient TCRKO can lead to on-target large and medium size deletions, indicating a potential safety risk of this procedure that needs monitoring. Importantly, TCR edition of ARI-0001 efficiently prevented allogeneic responses and did not detectably alter their phenotype, while maintaining a similar anti-tumor activity ex vivo and in vivo compared to unedited ARI-0001 CAR-T cells. In summary, we showed here that, although there are still some risks of genotoxicity due to genome editing, disruption of the TCR is a feasible strategy for the generation of functional allogeneic ARI-0001 CAR-T cells. We propose to further validate this protocol for the treatment of patients that do not fit the requirements for standard autologous CAR-T cells administration. 2022-11-28T09:21:29Z 2022-11-28T09:21:29Z 2022-10-06 journal article Maldonado-Pérez N... [et al.] (2022) Efficacy and safety of universal (TCRKO) ARI-0001 CAR-T cells for the treatment of B-cell lymphoma. Front. Immunol. 13:1011858. doi: [10.3389/fimmu.2022.1011858] https://hdl.handle.net/10481/78149 10.3389/fimmu.2022.1011858 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional Frontiers