In November 2015, David Weiner and colleagues at the University of Pennsylvania became the first to show evidence for a therapeutic vaccine against human papillomavirus (HPV)-induced cervical neoplasia (Trimble CL, Morrow MP, Kraynyak KA, et al. “Safety, efficacy, and immunogenicity of VGX-3100, a therapeutic synthetic DNA vaccine targeting human papillomavirus 16 and 18 E6 and E7 proteins for cervical intraepithelial neoplasia 2/3: a randomized, double-blind, placebo-controlled phase 2b trial,” The Lancet. 2015 Nov 21;386(10008): 2078-88).
The authors constructed DNA plasmids representing HPV genes E6 and E6, the protein products of which cause cells to develop cancerous changes. Then they selected a group of 167 women for their study, all of whom had cervical changes from a previous HPV infection classified as cervical intraepithelial neoplasia 2/3, a requisite step in the development of cervical cancer. The patients were divided into two groups: 125 women received 6 milligrams of the HPV DNA E6 and E7 constructs by electroporation of the skin to assure adequate delivery of the plasmids; the remaining 42 patients received a placebo. After 36 weeks both groups were assessed to determine whether the CIN2/3 lesions had regressed. The authors found that in the treatment group, 53 (49%) of recipients had regressed to CIN1 or CIN0, whereas 11 (30.6%) of placebo recipients had experienced regression. These differences were statistically significant (p=0.034).
This study supports the further evaluation of HPV DNA E6 and E7 as a possible non-surgical option for the treatment of CIN2/3.