Efficacy of HPV-16/18 AS04-adjuvanted vaccine against cervical infection and precancer in young women: final event-driven analysis of the randomised, double-blind PATRICIA trial

We report final event-driven analysis data on the immunogenicity and efficacy of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine in young women aged 15-25 years from the PApilloma TRIal against Cancer In young Adults (PATRICIA; NCT001226810). The total vaccinated cohort (TVC) included all randomised participants who received at least one vaccine dose (vaccine, n=9319; control, n=9325) at months 0, 1 and/or 6. The TVC-naïve (vaccine, n=5822; control, n=5819) had no evidence of high-risk HPV infection at baseline approximating adolescent girls targeted by most HPV vaccination programmes. Mean follow-up was approximately 39 months after the first vaccine dose in each cohort. At baseline, 26% of women in the TVC had evidence of past and/or current HPV-16/18 infection. HPV-16 and HPV-18 antibody titres post-vaccination tended to be higher among 15-17 year-olds than 18-25 year-olds. In the TVC, vaccine efficacy (VE) against cervical intraepithelial neoplasia grade 1 or greater (CIN1+), CIN2+ and CIN3+ associated with HPV-16/18 was 55.5% (96.1% CI: 43.2, 65.3), 52.8% (37.5, 64.7) and 33.6% (-1.1, 56.9). VE against CIN1+, CIN2+ and CIN3+ irrespective of HPV DNA was 21.7% (10.7, 31.4), 30.4% (16.4, 42.1) and 33.4% (9.1, 51.5) and consistently significant only in 15-17 year-old women (27.4% [10.8, 40.9], 41.8% [22.3, 56.7] and 55.8% [19.2, 76.9]). In the TVC-naïve, VE against CIN1+, CIN2+ and CIN3+ associated with HPV-16/18 was 96.5% (89.0, 99.4), 98.4% (90.4, 100) and 100% (64.7, 100); and irrespective of HPV DNA was 50.1% (35.9, 61.4), 70.2% (54.7, 80.9) and 87.0% (54.9, 97.7). VE against 12-month persistent infection with HPV-16/18 was 89.9% (84.0, 94.0) and against HPV-31/33/45/51 was 49.0% (34.7, 60.3). In conclusion, vaccinating adolescents before sexual debut has a substantial impact on the overall incidence of high-grade cervical abnormalities, and catch-up vaccination up to 18 years of age is most likely effective.status: publishe