Evaluation of Type Replacement Following HPV16/18 Vaccination: Pooled Analysis of Two Randomized Trials.

Background: Current HPV vaccines do not protect against all oncogenic HPV types. Following vaccination, type replacement may occur, especially if different HPV types competitively interact during natural infection. Because of their common route of transmission, it is difficult to assess type interactions in observational studies. Our aim was to evaluate type replacement in the setting of HPV vaccine randomized controlled trials (RCTs). Methods: Data were pooled from the Costa Rica Vaccine Trial (CVT; NCT00128661) and PATRICIA trial (NCT001226810)-two large-scale, double-blind RCTs of the HPV-16/18 AS04-adjuvanted vaccine-to compare cumulative incidence of nonprotected HPV infections across trial arms after four years. Negative rate difference estimates (rate in control minus vaccine arm) were interpreted as evidence of replacement if the associated 95% confidence interval excluded zero. All statistical tests were two-sided. Results: After applying relevant exclusion criteria, 21 596 women were included in our analysis (HPV arm = 10 750; control arm = 10 846). Incidence rates (per 1000 infection-years) were lower in the HPV arm than in the control arm for grouped nonprotected oncogenic types (rate difference = 1.6, 95% confidence interval [CI] = 0.9 to 2.3) and oncogenic/nononcogenic types (rate difference = 0.2, 95% CI = -0.3 to 0.7). Focusing on individual HPV types separately, no deleterious effect was observed. In contrast, a statistically significant protective effect (positive rate difference and 95% CI excluded zero) was observed against oncogenic HPV types 35, 52, 58, and 68/73, as well as nononcogenic types 6 and 70. Conclusion: HPV type replacement does not occur among vaccinated individuals within four years and is unlikely to occur in vaccinated populations.

Efficacy of fewer than three doses of an HPV-16/18 AS04-adjuvanted vaccine: combined analysis of data from the Costa Rica Vaccine and PATRICIA Trials.

BACKGROUND: There is some evidence to suggest that one or two doses of the HPV vaccine provides similar protection to the three-dose regimen. The main aim of the study was to ascertain HPV-16/18 vaccine efficacy in both full and naive cohorts and to explore protection conferred against non-vaccine HPV types, by number of doses received. METHODS: Summary data from the Costa Rica Vaccine Trial (CVT; NCT00128661) and ~the PATRICIA trial (NCT001226810), two phase 3, double-blind, randomised controlled clinical trials of the HPV-16/18 AS04-adjuvanted vaccine in young women, were combined in a post-hoc analysis (GlaxoSmithKline [GSK] e-track number 202142) to investigate the efficacy of fewer than three doses of the HPV-16/18 vaccine after 4 years of follow-up. Women were randomly assigned to receive three doses of the HPV-16/18 vaccine or to a control vaccine; yet, some received fewer doses. After exclusion of women with less than 12 months of follow-up or those who were HPV-16/18 DNA-positive at enrolment (for the HPV-16/18 endpoint), we calculated vaccine efficacy against one-time detection of incident HPV infections after three, two, and one dose(s). The primary study endpoint was one-time detection of first incident HPV-16/18 infections accumulated during the follow-up phase. FINDINGS: We assessed vaccine efficacy against incident HPV-16/18 infection in the modified total vaccinated cohort (22 327 received three doses, 1185 two doses, 543 one dose). Vaccine efficacy against incident HPV-16/18 infections for three doses was 77·0% (95% CI 74·7-79·1), two doses was 76·0% (62·0-85·3), and one dose was 85·7% (70·7-93·7). Vaccine efficacy against incident HPV-31/33/45 infections for three doses was 59·7% (56·0-63·0), two doses was 37·7% (12·4-55·9), and one dose was 36·6% (-5·4 to 62·2). Vaccine efficacy against incident HPV-16/18 infection for two-dose women who received their second dose at 1 month was 75·3% (54·2-87·5) and 82·6% (42·3-96·1) for those who received the second dose at 6 months (CVT data only). Vaccine efficacy against HPV-31/33/45 for two-dose women who received their second dose at 6 months (68·1%, 27·0-87·0; CVT data only), but not those receiving it at one month (10·1%, -42·0 to 43·3), was similar to the three-dose group. INTERPRETATION: 4 years after vaccination of women aged 15-25 years, one and two doses of the HPV-16/18 vaccine seem to protect against cervical HPV-16/18 infections, similar to the protection provided by the three-dose schedule. Two doses separated by 6 months additionally provided some cross-protection. These data argue for a direct assessment of one-dose efficacy of the HPV-16/18 vaccine. FUNDING: US National Cancer Institute, National Institutes of Health Office of Research on Women's Health, and Ministry of Health of Costa Rica (CVT); GlaxoSmithKline Biologicals SA (PATRICIA).

Overall efficacy of HPV-16/18 AS04-adjuvanted vaccine against grade 3 or greater cervical intraepithelial neoplasia: 4-year end-of-study analysis of the randomised, double-blind PATRICIA trial.

BACKGROUND: Cervical intraepithelial neoplasia grade 2 or greater (CIN2+) is the surrogate endpoint used in licensure trials of human papillomavirus (HPV) vaccines. Vaccine efficacy against CIN3+, the immediate precursor to invasive cervical cancer, is more difficult to measure because of its lower incidence, but provides the most stringent evidence of potential cancer prevention. We report vaccine efficacy against CIN3+ and adenocarcinoma in situ (AIS) in the end-of-study analysis of PATRICIA (PApilloma TRIal against Cancer In young Adults). METHODS: Healthy women aged 15-25 years with no more than six lifetime sexual partners were included in PATRICIA, irrespective of their baseline HPV DNA status, HPV-16 or HPV-18 serostatus, or cytology. Women were randomly assigned (1:1) to receive an HPV-16/18 AS04-adjuvanted vaccine or a control hepatitis A vaccine via an internet-based central randomisation system using a minimisation algorithm to account for age ranges and study sites. The patients and study investigators were masked to allocated vaccine. The primary endpoint of PATRICIA has been reported previously. In the present end-of-study analysis, we focus on CIN3+ and AIS in the populations of most clinical interest, the total vaccinated cohort (TVC) and the TVC-naive. The TVC comprised all women who received at least one vaccine dose, approximating catch-up populations and including sexually active women (vaccine n=9319; control=9325). The TVC-naive comprised women with no evidence of oncogenic HPV infection at baseline, approximating early adolescent HPV exposure (vaccine n=5824; control=5820). This study is registered with ClinicalTrials.gov, number NCT00122681. FINDINGS: Vaccine efficacy against CIN3+ associated with HPV-16/18 was 100% (95% CI 85·5-100) in the TVC-naive and 45·7% (22·9-62·2) in the TVC. Vaccine efficacy against all CIN3+ (irrespective of HPV type in the lesion and including lesions with no HPV DNA detected) was 93·2% (78·9-98·7) in the TVC-naive and 45·6% (28·8-58·7) in the TVC. In the TVC-naive, vaccine efficacy against all CIN3+ was higher than 90% in all age groups. In the TVC, vaccine efficacy against all CIN3+ and CIN3+ associated with HPV-16/18 was highest in the 15-17 year age group and progressively decreased in the 18-20 year and 21-25 year age groups. Vaccine efficacy against all AIS was 100% (31·0-100) and 76·9% (16·0-95·8) in the TVC-naive and TVC, respectively. Serious adverse events occurred in 835 (9·0%) and 829 (8·9%) women in the vaccine and control groups, respectively; only ten events (0·1%) and five events (0·1%), respectively, were considered to be related to vaccination. INTERPRETATION: PATRICIA end-of-study results show excellent vaccine efficacy against CIN3+ and AIS irrespective of HPV DNA in the lesion. Population-based vaccination that incorporates the HPV-16/18 vaccine and high coverage of early adolescents might have the potential to substantially reduce the incidence of cervical cancer. FUNDING: GlaxoSmithKline Biologicals.