Therapeutic Vaccine p16 – VicOryx
The human cyclin-dependent kinase inhibitor p16INK4a is a tumor antigen expressed in various cancers, including lung and breast cancer. In normal cells, p16INK4a is rarely expressed and leads to immediate senescence. In all cancers associated with high risk human papilloma virus (HR-HPV), p16INK4a is constantly expressed as an early consequence of HR-HPV-mediated cell transformation.
About 5% of all cancers are associated with HR-HPV including virtually all cervical cancers, 85-95% of anal and vulvar cancers, 20-40% of vaginal and penile cancers and 30-60% of head and neck cancers. Currently, two prophylactic vaccines are on the market that induce HPV-type specific protective immunity but do not have a therapeutic effect on HPV infections.
In patients with HR-HPV-associated cancers, humoral and cellular immune responses against p16INK4a occur spontaneously. In healthy people, such immune responses have not been observed.
Mode of Action
The observation that p16INK4a expression triggers specific immune reactions in patients is the basis of the vaccination approach with therapeutic vaccine p16 using a synthetic p16INK4a peptide to prevent outgrowth or to destroy HR-HPV-associated cancers.