Final Efficacy Analysis of 9-Valent Human Papillomavirus Vaccine Trial
The final efficacy analysis of a trial of 9-valent human papillomavirus (HPV) vaccine has shown a high preventive effect against disease due to the additional HPV pathogenic strains covered compared with the quadrivalent vaccine at up to 6 years. These findings were reported by Huh et al in The Lancet.
Study Details
In the double-blind trial, 14,215 women aged 16 to 26 years were randomized between September 2007 and December 2009 to receive the 9-valent vaccine (HPV 6, 11, 16, 18, 31, 33, 45, 52, and 58; n = 7,106) or the quadrivalent vaccine (HPV 6, 11, 16, and 18; n = 7,109). The primary outcomes were the incidence of high-grade cervical disease (cervical intraepithelial neoplasia grade 2 or 3, adenocarcinoma in situ, invasive cervical carcinoma), vulvar disease (vulvar intraepithelial neoplasia grade 2/3, vulvar cancer), and vaginal disease (vaginal intraepithelial neoplasia grade 2/3, vaginal cancer) related to HPV 31, 33, 45, 52, and 58 and noninferiority (excluding a decrease of 1.5 times) of anti-HPV 6, 11, 16, and 18 antibody geometric mean titers.
Vaccine Efficacy
In the per-protocol population, the incidence of high-grade cervical, vulvar, and vaginal disease related to HPV 31, 33, 45, 52, and 58 was 0.5 cases per 10,000 person-years in the 9-valent group and 19.0 cases/10,000 person-years in the quadrivalent group, representing efficacy of 97.4%. Geometric mean titers for HPV 6, 11, 16, and 18 in the 9-valent group were noninferior to those in the quadrivalent group from 1 month to 3 years after vaccination. There were no clinically meaningful differences in serious adverse events between the two groups.
The investigators concluded: “The [9-valent] HPV vaccine prevents infection, cytological abnormalities, high-grade lesions, and cervical procedures related to HPV 31, 33, 45, 52, and 58. Both the [9-valent] HPV vaccine and [quadrivalent] HPV vaccine had a similar immunogenicity profile with respect to HPV 6, 11, 16, and 18. Vaccine efficacy was sustained for up to 6 years. The [9-valent] HPV vaccine could potentially provide broader coverage and prevent 90% of cervical cancer cases worldwide.”
The study was funded by Merck & Co, Inc.
Warner K. Huh, MD, of the University of Alabama at Birmingham, is the corresponding author of The Lancet article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
