A study published in The Lancet showed that the human papillomavirus (HPV) vaccine, 9vHPV (Garadisil 9), is highly effective at preventing HPV infection and disease. The vaccine protects against HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58; HPV 16 and 18 are estimated to cause 70% of all cervical cancers. The researchers found that the vaccine is also highly effective at reducing the risk of having HPV 31/33/45/52/58-associated cervical cell abnormalities.
The phase 3 study was conducted by researchers from 18 countries and 105 study sites and randomized 14125 women between 16 and 26 years old to receive either 9vHPV (n=7106) or qHPV (Garadasil) (n=7109), an existing HPV vaccine that protects against HPV 16 and 18 as well as genital warts caused by HPV 6 and 11. The primary outcomes of the study were incidence of high-grade cervical disease, vulvar disease, and vaginal disease related to HPV 31, 33, 45, 52, and 58. The primary evaluation of efficacy was a superiority analysis in the per-protocol efficacy population. Supportive efficacy was analyzed in the modified intention-to-treat population and the primary evaluation of immunogenicity was a non-inferiority analysis.
The researchers found that the 9vHPV vaccine reduced the risk of developing HPV 31/33/45/52/58-related cervical, vaginal, and vulvar disease by 97.7% when compared to qHPV. It was noted that both vaccines were similar at preventing HPV 6/11/16/19-associated disease. Participants in the study were followed medically for 6 years after vaccination. No clinically meaningful differences in serious adverse events were noted in the study groups.
9vHPV became available in 2015 to protect both females and males against HPV-associated cancers and genital warts. The published study was funded by Merck & Co, Inc.