Efficacy, immunogenicity and safety of the HPV-16/18 AS04-adjuvanted vaccine in healthy Chinese women aged 18-25 years: Results from a randomized controlled trial

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 similar to 15 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 CIN11 and 93.8% (60.2, 99.9) against cytological abnormalities. VE against HPV-16/18 associated CIN11 and CIN21 was 100% (-50.4, 100) and 100% (-140.2, 100), respectively (no cases in the vaccine group and 4 CIN11 and 3 CIN21 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.