A 9-valent HPV (6/11/16/18/31/33/45/52/58) (9vHPV) vaccine was developed to provide protection against the HPV types already covered by the quadrivalent HPV (6/11/16/18) (qHPV) vaccine and the five HPV types most commonly associated with cervical cancer worldwide after HPV 16/18. Antibody response to prophylactic HPV vaccines is the basis for their effectiveness in preventing infection and disease related to vaccine HPV types. Here, we present the combined results of an analysis of 9vHPV vaccine immunogenicity in men age 16-26 years in clinical trials.
Immunogenicity analyses of two clinical trials of the 9vHPV vaccine (protocols 003 [NCT01651949] and 020 [NCT02114385]) were conducted by competitive Luminex immunoassay in males age 16-26 years in a per-protocol immunogenicity population (PPI) consisting of subjects seronegative at Day 1 for the tested HPV type. Immunogenicity was summarized in populations defined by age at vaccination (≤21 or >21 years of age), sexual orientation (heterosexual men [HM], men having sex with men [MSM]), race, and region of residence. Immunogenicity in a historic clinical trial of the qHPV vaccine in men age 16-26 years was also considered.
Of the randomized subjects, 1665 (99.8%) received at least one injection of 9vHPV vaccine. More than 99% of subjects who received 9vHPV vaccine and were in the PPI population were seropositive to the respective vaccine HPV type at 4 weeks post-Dose 3. For all subjects, geometric mean titers (GMT) for all nine HPV types were robust across age, sexual orientation, race, or region of residence. The magnitude of anti-HPV response to 9vHPV vaccine tended to decrease with increase in enrollment age. It was lower in MSM compared with HM with GMT ratios (MSM/HM) at 4 weeks post-Dose 3 ranging from 0.58 to 0.74, depending on the HPV type in the 9vHPV vaccine trials. GMTs were also lower in MSM versus HM in the historic qHPV vaccine trial, with GMT ratios ranging from 0.49 to 0.66. GMTs remained lower in MSM compared with HM after adjusting for age and region of residence in both vaccine clinical programs.
The 9vHPV vaccine was strongly immunogenic, as shown by high seroconversion rates (>99%) for all vaccine HPV types and robust HPV antibody responses regardless of race, geographic region, age, or sexual orientation. The lower immunogenicity in MSM compared with HM was not due to differences in baseline characteristics of age or region of residence and does not appear to have a meaningful clinical significance, as the qHPV vaccine was previously shown to be highly efficacious to prevent HPV infection and disease in MSM.