Therapeutic HPV Vaccination for Preventing Progression of Vulvar Intraepithelial Neoplasia

Human papillomavirus (HPV)-associated grade 3 vulvar intraepithelial neoplasia (VIN) often progresses to carcinoma. HPV-16 is the most common cause of VIN. In a phase II trial, investigators tested a vaccine against HPV-16 viral oncoproteins E6 and E7 in 22 women with HPV-16 grade 3 VIN (20 of whom received 3 or 4 doses).

All patients reported local reactions, and most reported fever (especially after the second dose); no adverse events exceeded grade 2. After 3 months of follow-up, 11 women reported symptomatic improvements, 5 achieved complete clinical and biopsy-documented responses (4 of which included loss of HPV-16), and 7 experienced partial responses. At 12 months, 9 women achieved complete responses and 6 had partial responses. Women with complete responses had smaller lesions at study entry than did those with partial or no responses. Vaccination was associated with HPV-specific CD4⁺ and CD8⁺ T cell responses; the magnitude of these cellular responses was higher among women who responded clinically than among those who did not.