Chimeric antigen receptor (CAR)-redirected T-cells have given rise to long-term durable remissions and remarkable objective response rates in patients with refractory leukemia, raising hopes that a wider application of CAR technology may lead to a new paradigm in cancer treatment. Similarly, transcription activator-like effector nuclease (TALEN™)-mediated gene editing has emerged as powerful strategy to introduce targeted mutations and holds great promise in therapeutics and offers multiple opportunities to improve CAR T-cell therapies. The knockout of the TCR alpha gene eliminates TCR expression and abrogates the donor T-cell's potential for graft-versus-host disease (GvHD) while maintaining a potent anti-tumoral activity. Thus it is possible to manufacture T-cells from third-party healthy donors to generate allogeneic “off-the-shelf” engineered CAR T-cells. Disruption of CD52 or deoxycytidine kinase genes may be a useful approach to makes T-cells compatible with concurrent oncology treatments such as alemtuzumab or Fludarabine while the bypass of key immune checkpoint regulators such PD1/PDL1 by inactivation of T-cells receptors would potentiate the antitumor T-cell response by impairing the interaction of the inhibitory receptor PD-1 on T cells with PD-L1 expressed on tumor cells. Here, we will present in vitro and in vivo proof of concepts demonstrating the potential of TALEN™-mediated gene editing for adoptive T-cell therapy.

Citation Format: Julien Valton, Anne-Sophie Gautron, Alexandre Juillerat, Philippe Duchateau, Laurent Poirot. Targeted genome modifications for improved adoptive immunotherapy. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A080.