In NG-001, 540 women were vaccinated,

536 (99%) completed the active phase of the study to one month after the last vaccine dose, and 514 (95%) were included in the primary ATP immunogenicity cohort. Reasons for withdrawal from each study and for exclusion from the ATP immunogenicity cohorts are shown in Fig. 1. In both studies, the mean age of participants was 21 years and the majority (≥93%) were of White Caucasian/European ethnic heritage (Table 2). In both studies, all women were seropositive for anti-HPV-16 and -18 antibodies one month after the last vaccine dose, as measured by ELISA, and remained seropositive through the last assessment (Month 48 for TETRA-051 and Month 12 for NG-001). However, there was a consistent trend for lower anti-HPV-16 and -18 GMTs one month after the last vaccine dose Tanespimycin nmr when HPV-31/45 or HPV-33/58 L1 VLPs were added to the HPV-16/18 AS04 vaccine (Fig. 2A and B, respectively). For all vaccines,

antibody titers were well above those associated with natural infection (i.e., 29.8 ELISA units [EU]/mL for anti-HPV-16 and 22.6 EU/mL for anti-HPV-18) [19]. In TETRA-051, there was no statistically selleck chemical significant difference between the 6 treatment groups in the semi-factorial design in terms of anti-HPV-16 GMTs (p = 0.3377) or -18 GMTs (p = 0.8364). In pairwise comparisons, GMTs were significantly lower for group A receiving HPV-16/18/31/45 AS04 (20/20/10/10 μg) compared with control for anti-HPV-16 antibodies (5505 [95% CI: 4386, 6910] versus 8742 [7075, 10,801] EU/mL; p = 0.0148) and anti-HPV-18 antibodies (2963 [2287, 3840] versus 5134 [4229, 6234] EU/mL; p = 0.0010) (Supplementary Table 1). For anti-HPV-16 GMTs, when the amount

of HPV-16 L1 VLP was increased from 20 μg to 30 μg (group E: 30/20/10/10 μg), there was no statistically significant difference versus control (7555 [5818, 9811] EU/mL; p = 0.4032), therefore, no further comparisons were made. For anti-HPV-18 GMTs, when the amount of HPV-18 L1 VLP was increased from 20 μg to 30 μg (group C: 20/30/10/10 μg), Tryptophan synthase the difference versus control was still statistically significant (3406 [2757, 4208] EU/mL; p = 0.0086). When the amount of HPV-31/45 VLPs was increased from 10 μg to 20 μg (group B: 20/20/20/20 μg), anti-HPV-18 GMTs were still lower versus control but not statistically different (3643 [2640, 5027] EU/mL; p = 0.0540). In Study NG-001, in women who were initially seronegative and HPV DNA negative for the corresponding HPV type, significantly lower anti-HPV-16 GMTs were observed for the HPV-16/18/33/58 AS04 vaccine containing 20 μg of each L1 VLP compared with control (6775 [5502, 8342] versus 11,246 [9133, 13,847] EU/mL; p = 0.0017) (Supplementary Table 1). However, anti-HPV-16 GMTs were significantly higher for the 3-dose tetravalent vaccine adjuvanted with AS01 (27,645 [22,713, 33,649] EU/mL; p < 0.0001) or AS02 (17,664 [14,534, 21,468] EU/mL; p = 0.0055) compared with control.