Neo-antigen Targeted Cancer Immunotherapy

Peptide-based cancer vaccines activate cancer specific T - cell immune-responses

Mutant RAS proteins are neo-antigens and drivers for development of cancer. RAS mutations are exclusively found in cancer cells and are therefore cancer specific targets for attacking cancer immunologically.

Targovax’s mutant RAS targeting immunotherapy is designed to activate T cells of the patient’s own immune system to attack the cancer cells. The immunotherapy is designed with mutant RAS mimicking peptides (antigens) that are long enough to be complexed with MHC class II molecules for stimulation of CD4+ T helper cells, and to allow antigen processing to shorter peptides that can be complexed with MHC class I molecules for stimulation of CD8+ cytotoxic T cells. The therapy is therefore able to activate both types of T cells necessary for achieving efficient anti-cancer immune activity.

Peptides are not immunogenic by themselves and need an adjuvant that can trigger the peptide immunization process resulting in activation of the desired anti-cancer specific T cells. The quality of the immune reaction to peptides is completely dependent on the adjuvant.

Targovax has selected the immune stimulator GM-CSF (granulocyte-macrophage colony-stimulating factor) as adjuvant - one of the most potent adjuvants used for peptide vaccinations since the early 1990s, producing a very convincing track record of potency and effectiveness. Targovax avoids the side effects associated with systemic administration of GM-CSF by only injecting minute quantities intra-dermally for local activation of the immune cells.

By targeting the central cancer neo-antigen mutant RAS and using the right type of adjuvant Targovax hope to succeed in developing a clinically efficient immunotherapy - which will benefit all patients with RAS mutated cancers.

Targovax’s RAS peptides are small proteins which can be produced chemically in quantities of many kilograms. They are also very stable and can be stored for several years.

Berit Iversen
VP, Head of CMC

T-cells are cells of the immune system that defend the host against intracellular changes and infections. By using peptides mimicking special intracellular changes, like RAS mutations, a subset of T-cells can be induced that recognizes cells with such mutations and triggers immunological eradication of these cells. T-cells also provide immunological memory and are rapidly retriggered upon reappearance of cells with the specific intracellular changes.

Read more about T-cells and the immune system.