HPV-16 oncoprotein vaccination for vulvar intraepithelial neoplasia

[kkmalaysia]

In more than three-quarters of cases, vulvar intraepithelial neoplasia (VIN) is linked to infection with human papillomavirus type 16 (HPV-16). The viral oncoproteins E6 and E7 are important in the development of VIN and progression to invasive cancer. Patients with grade 3 VIN are deficient in T-cells that react against HPV-16 E6 and E7 oncoproteins. Now, researchers in the Netherlands have assessed the use of vaccination against these proteins in the treatment of grade 3 VIN.

The vaccine was a synthetic long-peptide solution containing a mix of long peptides from the HPV-16 viral oncoproteins E6 and E7 in incomplete Freund’s adjuvant. Twenty women with HPV-16positive grade 3 VIN received three or four doses at 3-week intervals. At 3 months after the last dose, 12 women had had a clinical response, with five experiencing complete regression of VIN. Four of these became HPV-16-negative. At 12 months, 15 patients had had a clinical response, and nine had complete regression. The complete responses persisted at 24 months.

All patients had vaccine-induced T-cell responses. A complete response at 3 months was associated with stronger CD4+ and CD8+ T-cell responses. All 20 patients had local swelling at the injection site and 64% developed fever. Spontaneous regression of VIN occurs in <1.5% of patients.

Vaccination may induce cellular immunity and cause regression of VIN.

Kenter GG et al. Vaccination against HPV-16 oncoproteins for vulvar intraepithelial neoplasia. NEJM 2009;361:1838–1847; Finn OJ, Edwards RP. Human papillomavirus vaccine for cancer prevention. Ibid:1899–1901 (editorial).