ABSTRACT
This phase II/III, double-blind, randomized trial assessed the efficacy, immunogenicity and safety of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine in young Chinese women (ClinicalTrials.gov registration NCT00779766). Women aged 18-25 years from Jiangsu province were randomized (1:1) to receive HPV vaccine (n = 3,026) or Al(OH)3 control (n = 3,025) at months 0, 1 and 6. The primary objective was vaccine efficacy (VE) against HPV-16/18 associated 6-month persistent infection (PI) and/or cervical intraepithelial neoplasia (CIN) 1+. Secondary objectives were VE against virological and clinical endpoints associated with HPV-16/18 and with high-risk HPV types, immunogenicity and safety. Mean follow-up for the according-to-protocol cohort for efficacy (ATP-E) was â¼15 months after the third dose. In the ATP-E (vaccine = 2,889; control = 2,894), for initially HPV DNA negative and seronegative subjects, HPV-16/18 related VE (95% CI) was 94.2% (62.7, 99.9) against 6-month PI and/or CIN1+ and 93.8% (60.2, 99.9) against cytological abnormalities. VE against HPV-16/18 associated CIN1+ and CIN2+ was 100% (-50.4, 100) and 100% (-140.2, 100), respectively (no cases in the vaccine group and 4 CIN1+ and 3 CIN2+ cases in the control group). At Month 7, at least 99.7% of initially seronegative vaccine recipients had seroconverted for HPV-16/18; geometric mean antibody titres (95% CI) were 6,996 (6,212 to 7,880) EU/mL for anti-HPV-16 and 3,309 (2,942 to 3,723) EU/mL for anti-HPV-18. Safety outcomes between groups were generally similar. The HPV-16/18 AS04-adjuvanted vaccine is effective, immunogenic and has a clinically acceptable safety profile in young Chinese women. Prophylactic HPV vaccination has the potential to substantially reduce the burden of cervical cancer in China.
Subject(s)
Human papillomavirus 16/isolation & purification , Human papillomavirus 18/isolation & purification , Papillomavirus Infections/prevention & control , Papillomavirus Vaccines/therapeutic use , Uterine Cervical Dysplasia/prevention & control , Uterine Cervical Neoplasms/prevention & control , Adolescent , Adult , China , DNA, Viral/genetics , Double-Blind Method , Female , Follow-Up Studies , Humans , Neoplasm Grading , Papillomavirus Infections/immunology , Papillomavirus Infections/virology , Polymerase Chain Reaction , Treatment Outcome , Uterine Cervical Dysplasia/immunology , Uterine Cervical Dysplasia/virology , Uterine Cervical Neoplasms/immunology , Uterine Cervical Neoplasms/virology , Young AdultABSTRACT
BACKGROUND: Cervical cancer is a major public health problem for women in sub-Saharan Africa. Availability of a human papillomavirus (HPV) vaccine could have an important public health impact. METHODS: In this phase IIIb, double-blind, randomized, placebo-controlled, multicenter trial (NCT00481767), healthy African girls and young women seronegative for human immunodeficiency virus (HIV) were stratified by age (10-14 or 15-25 years) and randomized (2:1) to receive either HPV-16/18 AS04-adjuvanted vaccine (n = 450) or placebo (n = 226) at 0, 1, and 6 months. The primary objective was to evaluate HPV-16/18 antibody responses at month 7. Seropositivity rates and corresponding geometric mean titers (GMTs) were measured by enzyme-linked immunosorbent assay. RESULTS: In the according-to-protocol analysis at month 7, 100% of initially seronegative participants in the vaccine group were seropositive for both anti-HPV-16 and anti-HPV-18 antibodies (n = 130 and n = 128 for 10-14-year-olds, respectively; n = 190 and n = 212 for 15-25-year-olds). GMTs for HPV-16 and HPV-18 were higher in 10-14-year-olds (18 423 [95% confidence interval, 16 185-20 970] and 6487 [5590-7529] enzyme-linked immunosorbent assay units (EU)/mL, respectively) than in 15-25-year-olds (10 683 [9567-11 930] and 3743 [3400-4120] EU/mL, respectively). Seropositivity was maintained at month 12. No participant withdrew owing to adverse events. No vaccine-related serious adverse events were reported. CONCLUSIONS: The HPV-16/18 AS04-adjuvanted vaccine was highly immunogenic and had a clinically acceptable safety profile when administered to healthy HIV-seronegative African girls and young women.
Subject(s)
Adjuvants, Immunologic/administration & dosage , Aluminum Hydroxide/administration & dosage , Human papillomavirus 16/immunology , Human papillomavirus 18/immunology , Lipid A/analogs & derivatives , Papillomavirus Infections/prevention & control , Papillomavirus Vaccines/administration & dosage , Adjuvants, Immunologic/adverse effects , Adolescent , Adult , Africa South of the Sahara , Aluminum Hydroxide/adverse effects , Antibodies, Viral/blood , Child , Double-Blind Method , Drug-Related Side Effects and Adverse Reactions/epidemiology , Enzyme-Linked Immunosorbent Assay , Female , Humans , Lipid A/administration & dosage , Lipid A/adverse effects , Papillomavirus Infections/complications , Papillomavirus Infections/virology , Papillomavirus Vaccines/adverse effects , Placebos/administration & dosage , Uterine Cervical Neoplasms/prevention & control , Uterine Cervical Neoplasms/virology , Young AdultABSTRACT
Protection against oncogenic non-vaccine types (cross-protection) offered by human papillomavirus (HPV) vaccines may provide a significant medical benefit. Available clinical efficacy data suggest the two licensed vaccines (HPV-16/18 vaccine, GlaxoSmithKline Biologicals (GSK), and HPV-6/11/16/18 vaccine, Merck & Co., Inc.) differ in terms of protection against oncogenic non-vaccine HPV types -31/45. The immune responses induced by the two vaccines against these two non-vaccine HPV types (cross-reactivity) was compared in an observer-blind study up to Month 24 (18 mo post-vaccination), in women HPV DNA-negative and seronegative prior to vaccination for the HPV type analyzed (HPV-010 [NCT00423046]). Geometric mean antibody titers (GMTs) measured by pseudovirion-based neutralization assay (PBNA) and enzyme-linked immunosorbent assay (ELISA) were similar between vaccines for HPV-31/45. Seropositivity rates for HPV-31 were also similar between vaccines; however, there was a trend for higher seropositivity with the HPV-16/18 vaccine (13.0-16.7%) versus the HPV-6/11/16/18 vaccine (0.0-5.0%) for HPV-45 with PBNA, but not ELISA. HPV-31/45 cross-reactive memory B-cell responses were comparable between vaccines. Circulating antigen-specific CD4+ T-cell frequencies were higher for the HPV-16/18 vaccine than the HPV-6/11/16/18 vaccine (HPV-31 [geometric mean ratio [GMR] =2.0; p=0.0002] and HPV-45 [GMR=2.6; p=0.0092]), as were the proportion of T-cell responders (HPV-31, p=0.0009; HPV-45, p=0.0793). In conclusion, immune response to oncogenic non-vaccine HPV types -31/45 was generally similar for both vaccines with the exception of T-cell response which was higher with the HPV-16/18 vaccine. Considering the differences in cross-protective efficacy between the two vaccines, the results might provide insights into the underlying mechanism(s) of protection.