While in vivo CAR-T therapies eliminate complex ex vivo manufacturing, they introduce a new critical variable: the patient's own immune system. The therapy's efficacy relies on modifying T-cells within the body, but each patient's immune status is different, especially after prior treatments. This makes optimizing and standardizing the dose a significant challenge compared to engineered cell therapies.

The drug exhibits a multimodal mechanism. It not only reverses chemoresistance and halts tumor growth but also 'turns cold tumors hot' by forcing cancer cells to display markers that make them visible to the immune system. This dual action of direct attack and immune activation creates a powerful synergistic effect.

The industry's focus on antibodies, which are easy to generate, may be a case of technology dictating the science. Dr. Radvanyi argues that natural ligand-receptor interactions, which often rely on lower affinity and higher avidity, could offer a more nuanced and effective way to modulate immune pathways than high-affinity agonist antibodies.

Create's strategy is not limited to a single cell type. They view success in solid tumors as requiring the programming of all immune cells. Their platform can specifically engineer myeloid cells, T-cells, and NK cells in vivo, orchestrating a coordinated, multi-pronged attack on cancer.

Instead of focusing solely on T-cells, Create's platform first targets myeloid cells, which constitute up to 60% of some solid tumors. Programming these cells transforms the tumor microenvironment, enabling a 5-10x influx of CD8 T-cells. This overcomes a key barrier for T-cell therapies in solid tumors.

While personalized cancer vaccines require extracting and processing a patient's tumor, Create Medicines' in vivo approach is entirely off-the-shelf. By delivering the programming directly into the body, they enable the patient's own immune system to do the complex, personalized work of attacking the cancer itself.

While complex gene editing may be challenging in vivo, Colonia's platform presents a novel opportunity: targeting different immune cell types (e.g., T-cells and NK cells) with distinct payloads in a single treatment. This could create synergistic, multi-pronged attacks on tumors, a paradigm distinct from current ex vivo methods which focus on engineering a single cell type.

Unlike broad delivery systems like LNPs, Sana's Fusagen technology uses a modified viral component as a "logic gate." It is engineered to bind to a specific cell target, which then triggers a conformational change that fuses the payload directly into the cell's cytoplasm. This two-step mechanism aims for higher specificity and lasting effect.

Unlike many cell therapies, Rion's platelet-derived exosomes are devoid of the self/non-self surface markers that trigger immune rejection. This "immune privilege" is a critical biological advantage, allowing the product to be used as a universal, off-the-shelf therapy for any patient without needing donor matching.