Phase 1 study of HPV16-specific immunotherapy with E6E7 fusion protein and ISCOMATRIX adjuvant in women with cervical intraepithelial neoplasia

Abstract

Purpose: Persistent infection of cervical epithelium with "high risk" human papillomavirus (HPV) results in cervical intraepithelial neoplasia (CIN) from which squamous cancer of the cervix can arise. A study was undertaken to evaluate the safety and immunogenicity of an HPV16 immunotherapeutic consisting of a mixture of HPV16 E6E7 fusion protein and ISCOMATRIX adjuvant (HPV16 Immunotherapeutic) for patients with CIN.

Experimental design: Patients with CIN (n = 31) were recruited to a randomised blinded placebo controlled dose ranging study of immunotherapy.

Results: Immunotherapy was well tolerated. Immunised subjects developed HPV16 E6E7 specific immunity. Antibody, delayed type hypersensitivity, in vitro cytokine release, and CD8 T cell responses to E6 and E7 proteins were each significantly greater in the immunised subjects than in placebo recipients. Loss of HPV16 DNA from the cervix was observed in some vaccine and placebo recipients.

Conclusions: The HPV16 Immunotherapeutic comprising HPV16E6E7 fusion protein and ISCOMATRIX adjuvant is safe and induces vaccine antigen specific cell mediated immunity.