Our Take
This is a partnership announcement framed as a technical advance, but the actual work is still in proof-of-concept phase with no published benchmarks or independent validation.
Why it matters
In vivo CAR-T manufacturing could reduce complexity and cost compared to ex vivo approaches, but the field still relies on viral vectors due to safety and efficacy trade-offs. Non-viral alternatives remain unproven at scale.
Do this week
Cell therapy engineers: monitor Circio and Tcelltech's CD19 CAR-T functional phase results when published, but do not plan production changes until durability data matches or exceeds viral-vector baselines.
Circio and Tcelltech start staged collaboration
Norway-based Circio and Germany-based Tcelltech announced a research partnership to combine two delivery technologies for engineered T-cell therapies. Circio brings circVec, a circular RNA expression platform. Tcelltech contributes nanoSMAR, a non-viral, episomal DNA vector with high cargo capacity (company-reported). The goal is to engineer CAR-T and TCR-T cells using non-viral delivery for in vivo applications.
The collaboration follows two phases. An initial proof-of-concept stage will measure how strongly and durably the combined technologies drive gene expression in primary human T cells. A second functional phase will generate CD19-directed CAR-T cells and test their tumor-killing capacity in vitro.
The catch is manufacturing reality
Ex vivo CAR-T manufacturing is complex and costly. The field is shifting toward in vivo approaches, which would engineer T cells directly in the patient and reduce manufacturing burden. However, current in vivo therapies rely on viral vectors, which carry integration and immune-response risks (per Richard Harbottle, Tcelltech's head of vector technology).
Non-viral alternatives promise lower safety risk and larger payload capacity than viral systems. The nanoSMAR platform can carry more genetic material than viral vectors allow, enabling multi-gene constructs and complex regulatory elements. But non-viral approaches have not yet matched viral-vector durability or expression levels in published, independent benchmarks. This partnership is testing whether the combination of episomal DNA and circular RNA can close that gap.
The research is early. Neither company has published comparative data. No independent lab has reproduced these results. The field will wait for the functional-phase results on CAR-T killing capacity and transgene persistence before reassessing whether non-viral in vivo approaches are viable at clinical scale.
Watch the second-phase data
Cell and gene therapy teams should monitor the CD19 CAR-T functional phase when results appear. Ask for three specifics: durability of circVec and nanoSMAR-driven CAR expression over time, comparison against a viral-vector control arm, and whether expression levels sustain long enough to kill target tumors in vitro. Until those results are published and independently reviewed, treat this as an exploratory collaboration, not a validated alternative to current manufacturing pathways.