The Human Papillomavirus (HPV) is the aetiological cause of many different tumours including cervical, ano-genital and head/neck cancers. No specific therapies exist for the treatment of these tumours able to avoid recurrence of lesions. Targeting the HPV-associated antigens (i.e. the E7 and E6 oncoproteins) offers the possibility to tailor intervention and produce specific anti-HPV tumour therapies.
The technology is the field of immunotherapy (therapeutic vaccines) for HPV-associated tumours. It is based, in particular, on a genetic vaccine where a 'disarmed' version of the gene encoding the E7 oncoprotein of HPV 16 is fused to a plant gene coding for a mutated plant protein ('saporin' of Saponaria officinalis). Given the plant origin, our approach should ensure fewer problems in clinical use with respect to other strategies considered for the same class of drugs (where a tumour-specific antigen is potentiated by fusion with human-derived sequences such as HSPs, calreticulin or cytokines). The effect is the regression of cancerous lesions in two different mouse models (including an orthotopic model for head and neck tumours), in particular after intra-tumour administration. The 'know-how' already developed can be implemented and adapted to other cancers where the associated tumour-specific antigens are known
Genetic vaccination is a promising tool due to tailorability, ease of preparation, inexpensiveness and stability. The technology, related to immunotherapy of HPV-associated cancers (about 5% of all cancers), can be applied to all tumours whose tumour antigens are known.
We have shown that the gene encoding a variant of the plant protein 'saporin' from Saponaria officinalis is an innovative immune-stimulator able to elicit a cell-mediated immune response against the specific tumour antigen to which it is fused, crucial to block cancer growth or induce regression. This has been verified in two different mouse models (one of which is an orthotopic model for head/neck tumours). Unlike most therapeutic strategies currently being tested for genetic vaccines, the proposed approach is based on innovative molecules with minor implications for clinical use (induction of tolerance or autoimmunity). The anti-tumour immunotherapy (associated with 'classical treatments') is collecting amazing results in the clinical field. The clinical trial of our molecules would be the natural consequence of our studies.
The technology has been patented: Franconi R, Spanò L, Venuti A, Massa S. ‘Vaccines based on genetic chimera of viral and/or tumoral antigens and plant proteins’. European patent EP2456785. Notified in Italy, France and Germany. Date of filing: 21.07.2010