Immunogenicity and safety of two novel human papillomavirus 4- and 9-valent vaccines in Chinese women aged 20-45 years: A randomized, blinded, controlled with Gardasil (type 6/11/16/18), phase III non-inferiority clinical trial.

BACKGROUND

Human papillomavirus (HPV) infections were the main cause of anogenital cancers and warts. HPV 6/11/16/18 vaccines provide protection against the high-risk types of HPV responsible for 70% of cervical cancers and 90% of genital warts. This randomized, blinded, non-inferiority phase III trial was to determine whether immunogenicity and tolerability would be non-inferior among women after receiving two novel 4- and 9-valent HPV vaccines (4vHPV, HPV 6/11/16/18; 9vHPV, HPV 6/11/16/18/31/33/45/52/58) compared with those receiving Gardasil 4 (4-valent).

METHODS

1680 females between 20 and 45 years were randomized in a 2:1:1 ratio to 20-26, 27-35, or 36-45 y groups. Subjects then equally assigned to receive 4vHPV, 9vHPV or Gardasil 4 (control) vaccine at months 0, 2, and 6. End points included non-inferiority of HPV-6/11/16/18 antibodies for 4vHPV versus control, and 9vHPV versus control and safety. The immunogenicity non-inferiority was pre-defined as the lower bound of 95% confidence interval (CI) of seroconversion rate (SCR) difference > -10% and the lower bound of 95% CI of geometric mean antibody titer (GMT) ratio > 0.5.

RESULTS

Among the three vaccine groups, more than 99% of the participants seroconverted to all 4 HPV types. The pre-specified statistical non-inferiority criterion for the immunogenicity hypothesis was met: all the lower bounds of 95% CIs on SCR differences exceeded -10% for each vaccine HPV type and the corresponding lower bounds of 95% CIs for GMT ratios > 0.5. Across vaccination groups, the most common vaccination reaction were injection-site adverse events (AEs), including pain, swelling, and redness. General and serious AEs were similar in the three groups. There were no deaths.

CONCLUSIONS

This study demonstrated that the novel 4- and 9-valent HPV vaccination was highly immunogenic and generally well tolerated, both of which were non-inferior to Gardasil 4 in immunogenicity and safety.