Colonia Therapeutics' CEO argues that lentiviral delivery is ideal for oncology's required long-term persistence, while LNP delivery is better suited for autoimmune indications needing transient, multi-dose responses. This frames them as complementary technologies for different therapeutic "swim lanes" rather than as direct rivals in a zero-sum game.

While redosing may be an option for RNA-based in vivo CAR-Ts, viral vector-based platforms face a significant challenge. The potential for an immune response against the vector, a well-known issue in AAV gene therapy, could prevent subsequent doses and limit the long-term treatment strategy for these therapies.

Eli Lilly’s acquisition of in-vivo CAR-T company Colonia Therapeutics signals a deliberate strategy to bypass the crowded and still unproven allogeneic cell therapy space. By investing directly in technology that modifies T-cells inside the body, Lilly is betting it can leapfrog the current generation of cell therapies toward a more scalable platform.

Despite exciting early efficacy data for in vivo CAR-T therapies, the modality's future hinges on the critical unanswered question of durability. How long the therapeutic effects last, for which there is little data, will ultimately determine its clinical viability and applications in cancer versus autoimmune diseases.

Despite initial hype in oncology where business models struggled, cell therapy is finding a major new application in treating autoimmune diseases. By resetting the immune system, it can offer functional cures for debilitating conditions—a powerful and unexpected pivot for the technology platform.

The industry is on the cusp of a seismic therapeutic shift. Major Phase 3 readouts for siRNA/ASO in common diseases are expected in the next year. Simultaneously, in vivo CAR-T for autoimmunity represents a move from treating symptoms to potentially curing diseases, a true revolutionary step.

By acquiring both Kelonia (lentivirus) and Orna (RNA-based), Eli Lilly is strategically hedging its bets. This portfolio approach anticipates that different in vivo CAR-T delivery mechanisms will be optimal for different applications, such as durable lentivirus for cancer versus faster-acting RNA for autoimmune diseases.

Current cell therapies like CAR-T involve permanent genetic modifications, a risk acceptable only for last-resort cases. By using transient RNAs that disappear after a few days, this new approach eliminates long-term genetic risk, making cell therapies safe enough to be considered for first-line treatment.

Create Medicines chose LNP-delivered RNA for its in vivo platform to give physicians control. Unlike permanent lentiviral approaches, repeatable dosing allows for adapting to tumor antigen escape and managing durability and safety over time. This flexibility is a core strategic advantage for complex diseases like solid tumors.