Non-Viral Engineering of Primary Human T Cells <em>via</em> Homology-Mediated End-Joining Targeted Integration of Large DNA Templates

Many current adoptive cellular therapies rely on lenti- or retroviral vectors to engineer T cells for the expression of a chimeric antigen receptor (CAR) or exogenous T cell receptor (TCR) to target a specific tumor-associated antigen. Reliance on viral vectors for the production of therapeutic T cells significantly increases the timeline, cost, and complexity of manufacturing while limiting the translation of new therapies, particularly in the academic setting. A process is presented for efficient non-viral engineering of T cells using CRISPR/Cas9 and homology-mediated end joining to achieve targeted integration of large, multicistronic DNA cargo. This approach has achieved integration frequencies comparable to those of viral vectors while yielding highly functional T cells capable of potent anti-tumor efficacy both in vitro and in vivo. Notably, this method is rapidly adaptable to current good manufacturing practices (cGMP) and clinical scale-up, providing a near-term option for the manufacturing of therapeutic T cells for use in clinical trials.