Abstract 2801: The use of induced pluripotent stem (iPS) cells for the safety testing of enhanced affinity TCR-transduced T cells

Abstract

Abstract Engineering T cells with enhanced affinity T cell receptors (TCRs) is a promising therapeutic strategy for treating cancer. Engineered TCRs overcome the limitations of naturally occurring cancer-antigen specific TCRs which are typically of extremely low affinity and fail to efficiently recognize tumor cells. However, the use TCRs with enhanced affinity for adoptive therapy carries with it the risk that they might recognize normal tissue, either as on-target or off-target reactivity. Two fatalities in a clinical trial of an affinity-enhanced MAGE-A3-specific TCR have highlighted the need for more biologically relevant cellular testing systems to minimize cross-reactivity-related toxicity in future adoptive immunotherapy trials. Cellular Dynamics International Inc. supply a range of iCell products that are highly pure induced pluripotent stem (iPS) cell-derived cells that reproduce normal human biology in an in vitro setting. The advantage of iCell cultures over standard cultures of primary cells is that they better represent human organs with respect to their antigen presentation by HLA. In this study, a panel of iCell sub-types, representing major organs of the human body, were used to test the reactivity of T cells transduced with an enhanced affinity TCR for HLA-A2-restricted peptide antigen NY-ESO-1/LAGE-1157-165. IncuCyte FLR technology, which enables direct visualization of caspase-3/7-dependent apoptosis at 37°C in real time, was used to assess the killing of the iCells by NY-ESO TCR-transduced T cells over a 4 day time course. While potent killing by the NY-ESO TCR-transduced T cells was observed against an HLA-A2+, NY-ESO-1+/LAGE-1+ tumor cell line, A375, no reactivity was observed against any of the tested iCells sub-types unless the iCells were pulsed with 1 µM NY-ESO peptide. The screening of TCR-transduced T cells against biologically appropriate cell cultures, such as iCells, further advances preclinical safety testing of new TCRs for use in adoptive immunotherapy. Citation Format: Katherine J. Adams, Andrew B. Gerry, Joanna E. Brewer, Nicholas J. Pumphrey, Alan D. Bennett, Bent K. Jakobsen. The use of induced pluripotent stem (iPS) cells for the safety testing of enhanced affinity TCR-transduced T cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2801. doi:10.1158/1538-7445.AM2014-2801