First-Ever Therapeutic HPV Vaccine Promising Against Cervical Cancer

A therapeutic vaccine developed by Inovio Pharmaceuticals has shown the potential to impact precancerous lesions in the cervix of women infected with the human papillomavirus (HPV). Results of a phase 2b trial funded by the company, published in The Lancet, displayed efficacy against cervical intraepithelial neoplasias (CIN) in women treated with the vaccine.

Inovio is in the business of developing DNA-based immunotherapies against cancers and infectious diseases. The company developed a synthetic plasmid, VGX-3100, directed against HPV-16, HPV-18 E6 and E7 proteins. The phase 2b double-blind study described in the current paper recruited 167 patients (between October 19, 2011 and July 30, 2013) with CIN2/3 from 36 academic, across 36 academic and private gynecology practices in 7 countries. Patients were randomized to receive 6 mg VGX-3100 (125 patients) or placebo (42 patients), administered at 0, 4, and 12 weeks. Patients who received at least 1 dose were included in the safety study.

The primary efficacy endpoint of the trial was regression to CIN1 or normal pathology at 36 weeks following the first dose.

The researchers analyzed the data 2 ways; in the per-protocol analysis, 49.5% of VGX-3100-treated patients and 30.6% of placebo-treated patients had histopathologic regression. In the modified intention-to-treat analysis, 48.2% of vaccine recipients and 30.0% of placebo recipients had histopathologic regression. Erythema was more commonly observed in the vaccine-treated group compared with the placebo, in addition to injection-site reactions, which were see in most patients.

Based on their data, the authors claim that VGX-3100 could present a non-surgical therapeutic option for CIN2/3.

The rights to further develop this potential cure for cervical cancer have now been acquired by MedImmune Inc. Inovio modified the vaccine to include a DNA-based immune activator for IL-12 (INO-3112), and MedImmune has plans to evaluate INO-3112 in combination with immuno-oncology agents.