Circio and Tcelltech announced a collaboration to build next-generation in vivo CAR-T and TCR-T approaches by combining Circio’s circVec circular RNA expression technology with Tcelltech’s non-viral nanoSMAR episomal DNA vector. The staged program will first compare gene expression strength and durability in primary human T cells, followed by functional testing using CD19-directed CAR T cells designed to kill tumor cells. The companies argue the non-viral delivery strategy aims to avoid viral-vector safety concerns and enable scalable, cost-effective manufacturing. If successful, the approach could shift engineered T-cell development toward non-integrating, higher-cargo-capacity delivery systems that may broaden access beyond bespoke ex vivo manufacturing.