Human papillomavirus 16/18 AS04-adjuvanted cervical cancer vaccine: immunogenicity and safety in 15-25 years old healthy Korean women.

Abstract

The study assessed the immunogenicity and safety of human papillomavirus (HPV)-16/18 AS04-adjuvanted cervical cancer vaccine in healthy Korean women aged 15-25 years.
Phase IIIB, double-blind, randomised (2:1), multi-centre trial was conducted in Korea from June 2007 to March 2008. The study enrolled 225 women in the HPV (N=149) and placebo (N=76) groups who received three doses of HPV-16/18 AS04-adjuvanted vaccine or placebo (aluminium hydroxide) administered intramuscularly at 0, 1, and 6 months and were followed until one month post-dose 3. Serum samples were collected pre-vaccination and one month post-dose 3. Safety and reactogenicity data were collected throughout.
In this trial, 208 women completed the study (141 in HPV group; 67 in placebo group). At month 7, all initially seronegative women had seroconverted for HPV-16 and HPV-18 antibodies with anti-HPV-16 and anti-HPV-18 geometric mean titres of 9,351.4 El.U/mL (95% CI, 8,145.5 to 10,735.8) and 4204.1 El.U/mL (95% CI, 3,626.5 to 4,873.6), respectively. Initially seropositive women showed similar increase in geometric mean titre levels. Compliance to the three dose vaccination course was 95.3% in HPV and 89.5% in placebo group. Solicited local (pain) and general (fatigue, myalgia or headache) symptoms were commonly reported in both groups. Three serious adverse events were reported (two in HPV group; one in placebo group), all unrelated to vaccination by the investigator; all recovered.
The HPV-16/18 AS04-adjuvanted vaccine was highly immunogenic with a clinically acceptable safety profile in Korean women. This study was in line with previous global studies in Europe, North America, and Brazil. (ClinicalTrials.gov number, NCT 00485732.).

Full text

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Objective: The study assessed the immunogenicity and safety of human papillomavirus (HPV)-16/18 AS04-adjuvanted cervical
cancer vaccine in healthy Korean women aged 15-25 years.
Methods: Phase IIIB, double-blind, randomised (2:1), multi-centre trial was conducted in Korea from June 2007 to March 2008.
The study enrolled 225 women in the HPV (N=149) and placebo (N=76) groups who received three doses of HPV-16/18 AS04-adju-
vanted vaccine or placebo (aluminium hydroxide) administered intramuscularly at 0, 1, and 6 months and were followed until
one month post-dose 3. Serum samples were collected pre-vaccination and one month post-dose 3. Safety and reactogenicity
data were collected throughout.
Results: In this trial, 208 women completed the study (141 in HPV group; 67 in placebo group). At month 7, all initially seronega-
tive women had seroconverted for HPV-16 and HPV-18 antibodies with anti-HPV-16 and anti-HPV-18 geometric mean titres of
9,351.4 El.U/mL (95% CI, 8,145.5 to 10,735.8) and 4204.1 El.U/mL (95% CI, 3,626.5 to 4,873.6), respectively. Initially seropositive
women showed similar increase in geometric mean titre levels. Compliance to the three dose vaccination course was 95.3% in
HPV and 89.5% in placebo group. Solicited local (pain) and general (fatigue, myalgia or headache) symptoms were commonly
reported in both groups. Three serious adverse events were reported (two in HPV group; one in placebo group), all unrelated to
vaccination by the investigator; all recovered.
Conclusion: The HPV-16/18 AS04-adjuvanted vaccine was highly immunogenic with a clinically acceptable safety profile in Korean
women. This study was in line with previous global studies in Europe, North America, and Brazil. (ClinicalTrials.gov number, NCT
00485732.)
Keywords: AS04-adjuvanted, Cervical cancer, Geometric mean titres, Human papillomavirus-16/18, Immunogenicity,
Sero con version
Original Article
Human papillomavirus 16/18 AS04-adjuvanted cervical
cancer vaccine: immunogenicity and safety in 15-25
years old healthy Korean women
Seung Cheol Kim1, Yong Sang Song2, Young-Tae Kim3, Young Tak Kim4, Ki-Sung Ryu5, Bhavyashree Gunapalaiah6,
Dan Bi6, Hans L Bock6, Jong-Sup Park7
Department of Obstetrics and Gynecology, 1Ewha Womans University Mokdong Hospital, 2WCU Biomodulation in Major, Cancer
Research Institute, Seoul National University Hospital, 3Severance Hospital, Yonsei University College of Medicine, 4Asan Medical
Center, University of Ulsan College of Medicine, 5St. Mary’s Hospital, The Catholic University of Korea School of Medicine, Seoul,
Korea, 6GlaxoSmithKline Biologicals, Wavre, Belgium, 7Department of Obstetrics and Gynecology, Seoul St. Mary’s Hospital, The
Catholic University of Korea School of Medicine, Seoul, Korea
Received Mar. 2, 2011, Revised Apr. 5, 2011, Accepted Apr. 12, 2011
Correspondence to Jong-Sup Park
Department of Obstetrics and Gynecology, The Catholic University of Korea School of Medicine, 505 Banpo-dong, Seocho-gu, Seoul 137-040, Korea. Tel:
82-2-590-2596, Fax: 82-2-595-8774, E-mail: jspark@catholic.ac.kr
pISSN 2005-0380
eISSN 2005-0399
Copyright © 2011. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology and Colposcopy
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License
(http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and
reproduction in any medium, provided the original work is properly cited.
www.ejgo.org
J Gynecol Oncol Vol. 22, No. 2:67-75
DOI:10.3802/jgo.2011.22.2.67

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INTRODUCTION
Cervical cancer is the second most common form of cancer
in women worldwide, with approximately 555,100 new cases
and 309,800 deaths reported in 2007; 83% of these cervical
cancer deaths occur in developing countries [1]. The pattern
of cervical cancer incidence and mortality in Korea is similar to
that seen in a developing country setting [2].
In Korea, cervical cancer is the fifth most common malignant
cancer reported with over 3,000 women developing this
disease annually [3], and accounting for 9.8% of new cancer
cases in Korean women [4]. The age-standardised rate (ASR)
for cervical cancer has shown a decline from 19 per 100,000
women in 1993-1995 to 15 per 100,000 women in 1999-2002
in Korea [2]. According to Cancer Incidence in Five Continents
(Volume IX), the ASR for cervical cancer in Korea has shown to
be intermediate at 15.4 per 100,000 women [5].
Amongst the various risk factors associated with cervical
cancer [6], persistent infection with oncogenic human
papillomavirus (HPV) types is established as an essential
precursor to the development of cervical cancer [7,8]. Of
the 15 oncogenic HPV types identified, HPV-16 and HPV-
18 together account for approximately 70% of all invasive
cervical cancer (ICC) cases worldwide, with HPV-45, -33, and
-31 accounting for additional approximately 10% of reported
cases [9]. In Korea, HPV-16, -18, -58, -33, and -52 accounts for
80.8% of all ICC cases, while 65.1% of ICC are caused by HPV-
16 and -18 alone. The prevalence of HPV-58, -33, and -52 is
high in high-grade cervical intraepithelial neoplasia (CIN) and
invasive cancer in Korean women when compared to many
other countries [10].
The World Health Organisation (WHO) has recognised cervical
cancer and other HPV-related diseases as a global public health
problem and recommends the inclusion of routine HPV vacci-
nation in national immunisation programmes worldwide
[11]. The HPV-16/18 AS04-adjuvanted cervical cancer vaccine
(CervarixⓇ, GlaxoSmithKline [GSK] Biologicals, Rixensart, Belgi-
um) has been developed and licensed in more than 100 coun-
tries worldwide, including US, Europe, Japan, and Korea. In
addi tion, a pre-qualification has been awarded to CervarixⓇ
by the WHO to ensure access of the vaccine and help combat
cervical cancer in developing countries [12]. The vaccine has
been shown to be immunogenic and having a clinically
acceptable safety profile in global clinical studies [13-18],
and high efficacy against persistent HPV-16/18 infection and
CIN2+ up to 6.4 years after vaccination [13,19].
Over 58,000 girls and women are currently enrolled in/
have participated in clinical trials for the HPV-16/18 AS04-
adjuvanted cervical cancer vaccine. The vaccine is already in
use as part of routine immunisation programmes in countries
such as the Netherlands and the UK to protect women against
cervical cancer [20,21].
This phase IIIB study was conducted in healthy Korean
women aged 15-25 years to evaluate the immunogenicity,
safety and reactogenicity of the vaccine.
MATERIALS AND METHODS
　　
1. Study design and participants
Healthy Korean women aged 15-25 years at the time of first
vaccination were recruited for this phase IIIB, double-blind,
placebo-controlled, multi-centre trial conducted from June
2007 to March 2008 in six Korean centres (Study ID:107291).
Women were ran do mised (2:1, vaccine:placebo) to receive
three doses of either the HPV-16/18 AS04-adjuvanted vaccine
(HPV group), or Al(OH)3 placebo (ALU group); administered
intramuscularly according to a 0, 1, and 6 months schedule.
Study participants were to have a negative urine pregnancy
test before each vaccination and agree to use adequate con-
tra ceptive precautions over the vaccination period. Women
were excluded from participating in the study if they had
used any investigational or non-regi stered drug or vaccine,
were pregnant or lactating or plan ning/ likely to conceive du-
ring the study. Additionally, subjects with a history of HPV
vaccination, monophosphoryl lipid A (MPL) or AS04-adjuvant
administration, and those with a history of chronic diseases
such as autoimmune diseases or cancer were also excluded
from study participation.
The study was conducted in accordance with Good Clinical
Practice guidelines and adhered to all applicable regulatory
re quirements, including the Declaration of Helsinki. The study pro-
tocol and informed consent documentation were approved
by the Independent Ethics Committee or Institutional Review
Board of each study centre. All participants and/or parents/
guardians of the participants provided written informed con-
sent/assent prior to conduct and performance of any study-
related procedures.
　　
2. Vaccine composition
Each dose of the HPV-16/18 vaccine contained 20 mg each of
HPV-16 and -18 L1 (structural protein of HPV) virus like particle
and adjuvanted with the proprietary immunostimulatory AS04
adjuvant system (comprising 3-O desacyl-4’-MPL [50 mg] ad-
sorbed on aluminium hydroxide [Al(OH)3, 500 mg]) [18]. The
placebo contained 500 mg of aluminium as Al(OH)3 without
any viral antigen.
The HPV-16/18 AS04-adjuvanted cervical cancer vaccine was

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developed and manufactured by GSK Biologicals, Belgium. The
vaccine was supplied in 0.5 mL pre-filled individual syringes.
　　
3. Randomisation sequence and treatment allocation
The randomisation of the study vaccine/placebo was
performed at GSK Biologicals, using a standard statistical
analysis system programme. Random allocation of participants
was done with a 2:1 blocking scheme using an internet based
randomisation system (SBIR) at the investigator site. The
randomisation algorithm used a minimisation procedure.
The blocking system was used to ascertain that balance was
maintained between the treatment arms. A single treatment
number was utilised in the entire study to identify the vaccine
doses to be administered to the participant.
All participants and study personnel directly involved in the
study conduct were blinded throughout the study until the
last subject and last visit and the database was frozen.
4. Immunogenicity assessment
Blood samples (5 mL) were collected before vaccination and
one month post-dose 3 to evaluate the antibody response
against HPV-16 and HPV-18 using ELISA [22]. The assay cut-
off for anti-HPV-16 and anti-HPV-18 antibodies was ≥8 ELISA
units/millilitre (EL.U/mL) and ≥7 EL.U/mL, respectively [23].
5. Reactogenicity and safety assessment
Diary cards were given to participants or parents/guardians of
the participants on the day of vaccination to record solicited
and unsolicited (local/general) symptoms during the 7-day
and 30-day post-vaccination follow-up period, respectively.
Solicited local symptoms (pain, redness and swelling at
the injection site) and solicited general symptoms (fever,
headache, fatigue, gastrointestinal symptoms, myalgia,
arthralgia, rash, and urticaria) were recorded during the
7-day follow-up period after each vaccine/placebo dose.
The intensity of solicited symptoms was graded on a scale
of 0-3 based on the extent of discomfort experienced by the
participants. Grade 3 (severe) symptoms were defined as:
pain that prevented normal day-to-day activity, redness or
swelling with an injection site diameter greater than 50 mm,
temperature higher than 39oC as fever, urticaria distributed
on at least four body areas, or an adverse event (AE) that
prevented normal activities. Post-vaccination reactions
(urticaria or rash that appeared within 30 minutes of each
vaccine dose) were also documented immediately by the
investigator. Each solicited AEs and unsolicited AEs were
tabulated with exact 95% confidence intervals (CIs) for all
vaccine doses and overall.
Serious adverse events (SAEs), new onset chronic diseases
(NOCDs) such as autoimmune diseases, asthma, type I
diabetes and allergies, other medically significant conditions
(MSCs) and pregnancy/pregnancy outcomes were recorded
throughout the study period. An event was considered to be
an NOCD if it had not been recorded in the previous medical
history of the participants’ vaccination (i.e., new onset);
MSCs were defined as prompting an emergency room, or
a physician visit that is unrelated to common diseases or
routine visits for physical examination or vaccination, or SAEs
unrelated to common diseases.

6. Statistical analysis
Primary analysis of immunogenicity was performed on
the according-to-protocol (ATP) cohort, which included
all evaluable participants (those meeting all eligibility
criteria, complying with protocol defined procedures,
without elimination criteria during the study) for whom
immunogenicity data were available. The primary analysis of
safety was done on the total vaccinated cohort that included
all participants with at least one vaccine/placebo dose
administered.
A sample size of 120 evaluable participants in the HPV group
was required to demonstrate, with at least 92% power, that
seroconversion rates for HPV-16 and -18 one month post-dose
3 were not less than 90%. The power calculation was based
on a one-sided exact test for one binomial population, type
I error of 2.5% with the Bonferroni adjustment of beta using
PASS2005 (NCSS, Kaysville, UT, USA).
Seroconversion/seropositivity rates for anti-HPV-16 and
anti-HPV-18 antibodies were calculated with their 95% CI.
Seroconversion was defined as the appearance of antibodies
(i.e., titre ≥cut-off value) in the serum of subjects who are
seronegative before vaccination. A seropositive subject was
one whose serum antibody titres were ≥cut-off value prior to
vaccination. Geometric mean titres (GMTs) with 95% CI and
antibody titres range were also tabulated. GMT calculations
were performed by taking the anti-log of the mean of the log
antibody titres transformations. Antibody titres below the
assay cut-off were given an arbitrary value of half the cut-off
for GMT calculation.
All statistical analysis was performed using SAS ver. 9.1 (SAS
Inc., Cary, NC, USA) programme and Proc StatXact ver. 7.0 (Cytel
Inc., Cam bridge, MA, USA) software.
RESULTS

1. Study population
The study groups are outlined in (Fig. 1). A total of 225 women

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Table 1. Baseline serological status (ELISA) (total vaccinated cohort)
HPV-16
Seropositive
Seropositive
Seronegative
Seronegative
HPV-18
Seropositive
Seronegative
Seropositive
Seronegative
HPV group (N=149)
3 (2.1)
8 (5.5)
10 (6.8)
125 (85.6)
3 (-)
ALU group (N=76)
1 (1.3)
5 (6.6)
7 (9.2)
63 (82.9)
0 (-)
ALL (N=225)
4 (1.8)
13 (5.9)
17 (7.7)
188 (84.7)
3 (-)Serology not available for at least one vaccine antigen
HPV group, subjects who received the HPV-16/18 L1 VLP AS04-adjuvanted vaccine; ALU group, subjects who received Al(OH)3; N, number of
subjects in each group; n (%), number/percentage of subjects in the considered category.
Fig. 1. Study participants flowchart. N, total number of subjects; n, number of subjects with elimination code assigned excluding ones who
have been assigned a lower elimination code number.

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were enrolled of whom 208 completed the study (141 in the
HPV group and 67 in the ALU group). The ATP safety cohort
consisted of 208 women (140 in the HPV group and 68 in the
ALU group). The ATP cohort for immunogenicity included
204 women (137 in the HPV group and 67 in the ALU group)
(Fig. 1). The mean age of women was 22±2.37 years (total
vaccinated cohort). All of them were Asian with East Asian He-
ritage.
2. Immunogenicity
Seropositivity status at baseline was similar in the two groups.
Of the women in the total vaccinated cohort, 85.6% in the
HPV group and 82.9% in the ALU group were seronegative for
both HPV-16 and -18 antibodies before vaccination (Table 1).
In the ATP immunogenicity cohort, initially seronegative
women in the HPV-16/18 group showed 100% seroconversion
for anti-HPV-16 and anti-HPV-18 antibodies at one month
Table 3. Immune response to HPV-18 (according-to-protocol cohort for immunogenicity)
GroupPre-vaccination statusTimingNo.
≥7 EL.U/mL
% (95% CI)
0 (0.0-3.0)
100 (97.0-100)
100 (75.3-100)
100 (75.3-100)
9.6 (5.2-15.9)
100 (97.3-100)
0 (0.0-5.9)
5.0 (1.0-13.9)
100 (54.1-100)
83.3 (35.9-99.6)
9.0 (3.4-18.5)
12.1 (5.4-22.5)
GMT (95% CI)
HPV Seronegative Pre-vaccination
One month post-dose 3
Pre-vaccination
One month post-dose 3
Pre-vaccination
One month post-dose 3
Pre-vaccination
One month post-dose 3
Pre-vaccination
One month post-dose 3
Pre-vaccination
One month post-dose 3
122
122
13
13
135
135
61
60
3.5 (3.5-3.5)
4,204.1 (3,626.5-4,873.6)
16.3 (9.5-27.8)
4,595.0 (2,970.2-7,108.5)
4.1 (3.7-4.4)
4,240.2 (3,692.1-4,869.7)
3.5 (3.5-3.5)
3.8 (3.4-4.3)
15.6 (5.6-43.1)
14.1 (5.1-38.6)
4 (3.5-4.5)
4.3 (3.7-5.0)
Seropositive
Total
ALUSeronegative
Seropositive 6
6
Total67
66
HPV, subjects who received the HPV-16/18 L1 VLP AS04-adjuvanted vaccine; ALU, subjects who received Al(OH)3; Seronegative, subjects with
antibody titre <7 ELISA unit (EL.U)/mL prior to vaccination; Seropositive, subjects with antibody titre ≥7 EL.U/mL prior to vaccination; N, number
of subjects with pre-vaccination results available in each group; % (95%CI), percentage of subjects with concentration ≥ specified cut-off with
exact 95% confidence interval.
Table 2. Immune response to HPV-16 (according-to-protocol cohort for immunogenicity)
GroupPre-vaccination statusTiming No.
≥8 EL.U/mL
% (95% CI)
0 (0.0-2.9)
100 (97.1-100)
100 (71.5-100)
100 (71.5-100)
8.1 (4.1-14.0)
100 (97.3-100)
0 (0.0-5.9)
3.3 (0.4-11.3)
100 (54.1-100)
83.3 (35.9-99.6)
9.0 (3.4-18.5)
10.4 (4.3-20.3)
GMT (95% CI)
HPVSeronegativePre-vaccination
One month post-dose 3
Pre-vaccination
One month post-dose 3
Pre-vaccination
One month post-dose 3
Pre-vaccination
One month post-dose 3
Pre-vaccination
One month post-dose 3
Pre-vaccination
One month post-dose 3
125
125
11
11
136
136
61
61
4 (4.0-4.0)
9,351.4 (8,145.5-1,0735.8)
23 (12.2-43.3)
7,918.1 (4,683.5-13,386.7)
4.6 (4.2-5.1)
9,226.4 (8,085.4-10,528.4)
4 (4.0-4.0)
4.1 (3.9-4.3)
33.2 (14.9-73.8)
28.8 (9.2-89.6)
4.8 (4.1-5.7)
4.9 (4.2-5.8)
Seropositive
Total
ALUSeronegative
Seropositive6
6
Total67
67
HPV, subjects who received the HPV-16/18 L1 VLP AS04-adjuvanted vaccine; ALU, subjects who received Al(OH)3; Seronegative, subjects with
antibody titre <8 ELISA unit (EL.U)/mL prior to vaccination; Seropositive, subjects with antibody titre ≥8 EL.U/mL prior to vaccination; N, number
of subjects with pre-vaccination results available in each group; % (95%CI), percentage of subjects with concentration ≥ specified cut-off with
exact 95% confidence interval.