the relevance of the as04 adjuvant system to cervical ... · into virus-like particles...
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The relevance of the AS04 adjuvant system to cervical
cancer vaccination
Diane M Harper, MD, MPH, MSDartmouth College
GSK HPV 16/18 Vaccine HPV L1 Virus Like Particles and AS04
Recombinant L1 protein
Resemble intact viruses
Self-assemble into virus-like particles
Non-infectioushollow sphere
Antigen:20 µg L1 HPV-16 protein20 µg L1 HPV-18 protein
AS04 adjuvant system:
50 µg MPL adsorbed onto 500 µg Al(OH)3
ASO4 in HPV Vaccines
• Modern vaccine technology provides new means to control quality and/or quantity of vaccine antigen-specific immune responses
• AS04 represents a new generation of vaccine adjuvants, activating innate immunity to potentiate protective, adaptive immune responses
HPV cannot infect this skin without specific scarification or trauma.
Squamocolumnar junction
Squamous metaplasia
Normal cervix/vagina
• HPV virions rest on the basement membrane for up to 24 hours
• Antigen presenting cell (APC) stimulation can occur
• Lateral basal cell engulfment without APC recognition occurs
Antibody response to genital HPV in natural infections
• Detectable serum neutralizing antibody responses are to L1– Type specific– Antibody response is slow and weak– Evidence of memory since antibody can
persist for up to 10 years post sero-conversion
How do neutralising antibodies work?
The virus binds to its receptor on the cell and enters
Neutralising antibody binds to the virus surface blocking the interaction with the receptor and preventing virus entry
y
YYYYYY
YYY
YYYYYY
YYY
YYYYYY YYY YYY
YYY
YYY YYY
YYY
YYY
YYY
YYY
YYY
L1 protein coat has dissolved prior to entering the cell nucleus
L1 protein coat is no longer available, nor in the correct space• for immune recognition• to stimulate an anamnestic response
Residential/Latent/DormantResidential/Latent/Dormant
Vaccines can do nothing to the already HPV infected basal cell
EpisomalEpisomal
Multiple Multiple HPV HPV
virions virions per cellper cell
E4 importanceE4 importance
Nucleus of the superficial cell where the HPV virion capsule is made
This HPV is detectable by HCII because it is collected with the desquamating cells.
Why are antibody responses so poor in natural HPV infections?
• No viremia• HPV does not kill keratinocytes
– no inflammation– no pro-inflammatory cytokines– poor activation of epithelial antigen presenting cells
• Free virus particles are shed from mucosal surfaces with poor exposure to APC
HPV virions may auto-inoculate traumatized epithelium
New Ano-Genital Cancers Within 10 Yrs After CIN 1 Treatment
• 7,600 women treated for CIN 1 followed for 27 years
Kalliala I, Anttila A, Pukkala E, Nieminen P. BMJ 2005;331:1183–1185.
ReRe--infection by autoinoculation from already infected infection by autoinoculation from already infected basal cells is most probable cause.basal cells is most probable cause.
No lifetime protection from natural HPV infection.No lifetime protection from natural HPV infection.
Standardized Incidence Ratiowithin 10 years of follow up
3.1 (1.5–5.7)Cervix ca
3.7 (0.9–10.7)CIN 2
3.1 (1.4–6.2)CIN 1
New Ano-Genital Cancers After CIN 3 Treatment
• 3.7 million women followed for 37 years• History of CIN 3 treated vs. no CIN 3• Incidence rate ratios (IRR) for cancers of
Vagina Vulva Anus<1 yr 43 6 01-4 yrs 19 2 15-9 yrs 15 2 4≥10 yrs 5 2 5
Edgren G, Sparen P. Lancet Oncol 2007;8:311-16.
• Epithelial denudation will result in serous exudation and rapid access of serum IgGs to the new virus particles
Roberts J et al. IPV Prague 2006
Where HPV Vaccines may act within the Natural History of Infection
Where HPV Vaccines may act within the Natural History of Infection
Regression
Invasive Invasive CarcinomaCarcinoma
ProgressionProgression
HSIL
Progression
IntegratedIntegrated
CIN2CIN3
EpisomalEpisomalINFECTIOUS, TRANSMISSABLEINFECTIOUS, TRANSMISSABLE
CIN1
ASCUSLSIL
HR HPV Infection
Antibodies transudate
1 2Initial infectionAutoinoculation from persistent infection
Repeat HPV type specific natural infections occur equally in women after 5-7 years FU regardless of type specific serostatus
00.30.60.91.21.51.82.12.42.7
3
HPV 16 HPV 18 HPV 31
Seronegative Seropositive
Rat
e of
type
spe
cific
H
PV in
fect
ions
(%)
Antibody levels from natural infection are insufficientinsufficient to protect against new HPV
infections of the same type
Viscidi RP et al. CEBP. 2004; 13:324-327
10,049 women Guanacaste, Costa Rica NCI Study
92/
5360
19/
1492
37/
5384
16/
156543/
545911/
1490
Adjuvant Studies
• A given antibody response occurs to the L1 protein antigen
• Can the quantity of antibody response be increased by the AS04 adjuvant system?
AS04 vs. Alum
HPV 16/18 VLPs formulatedwith AS04
versus
HPV 16/18 VLPs formulated withaluminium hydroxide
Anti-V5 (HPV 16)**
**
**
** ** **
GM
T (
EU
/m
l) Anti-J4 (HPV 18)
* Statistically significantTime (months)
Giannini SL et al. Vaccine 2006
Neutralising antibody
AS04 adjuvant effect
Enhanced and sustained immunogenicity is maintained over 4 years
Al(OH)3AS04
0 8 16 24 32 40 480
100
200
300
400
8001000
****
** ** **
**
Al(OH)3AS04
0 8 16 24 32 40 480
100
200
300
400
8001000
Increased B-memory responseRelative frequency of HPV 16 and HPV 18 specific
B-memory cells in humans with 2 vaccine formulations
Giannini SL et al. Vaccine 2006
Phase II trial
• Long term efficacy and immunogenicity follow up study of Cervarix
Total follow-up time (months)0 7 12 18 [25–32] [33–38] [39–44] [45–50] [51–56] [57–62] [63–64]
10000
1000
100
10
1
≥11-fold
higherNatural infection Antibody level
Seropositivity ≥98%
log (ELU/ml)
High and Sustained HPV-16 Antibody Levels and Seropositivity up to 5.5 Years
AntiAnti--HPVHPV--16 IgG16 IgG
Harper D et al. Lancet 2006; 367: 1247-55; Presentation Gall S, AACR, Los Angeles, April 14-18, 2007
10000
1000
100
10
Total follow-up time (months)
≥11 fold
higher
Natural infection
1
0 7 12 18 [25-32] [33-38] [39-44] [45-50] [51-56] [57-62] [63-64]
Seropositivity ≥98%
log (ELU/ml)
High and Sustained HPV-18 Antibody Levels and Seropositivity up to 5.5 Years
AntiAnti--HPVHPV--18 IgG18 IgG
Harper D et al. Lancet 2006; 367: 1247-55; Presentation Gall S, AACR, Los Angeles, April 14-18, 2007
7 12 18 63-64
10
100
1000
10000
month
HP
V-1
6 G
MC
E
U/m
l (lo
g)
0 51-5639-44
Natural Infection
46–55 years36–45 years26–35 years15–25 years
Efficacy study15 to 25 years
at least 9-fold higher
HPV-16 Antibody Levels in 15-55 Year Olds Comparable
to those Observed in Efficacy Study
assay cut-off: 8 EU/mlHarper DM, et al. Lancet 2006; TF Schwarz ASCO 2006; S Gall AACR 2007
Natural Infection
7 12 18 63-64
10
100
1000
10000
month
HP
V-1
8 G
MC
E
U/m
l (lo
g)
0 51-5639-44
at least 9-fold higher
HPV-18 Antibody Levels in 15-55 Year Olds Comparable
to those Observed in Efficacy Study
46–55 years36–45 years26–35 years15–25 years
Efficacy study15 to 25 years
assay cut-off: 7 EU/mlHarper DM, et al. Lancet 2006; TF Schwarz ASCO 2006; S Gall AACR 2007
VLP vaccines generate high levels of antibody to HPV L1 –
Why are they so immunogenic?
• Delivered intramuscularly– Rapid access of VLPs to blood vessels and
local lymph nodes– Potent activators of APC induce good T
helper responses for B cells
Immune Response at the Mucosal Level
• Serum antibody responses against anti-HPV-16 and anti-HPV-18 elicited by the HPV-16/18 candidate vaccine are likely to represent an important, if not essential, aspect of providing protection against HPV-16 and/or HPV-18 cervical infections.
• One additional aspect of protection may be the detection of an effective immune response at disease-relevant sites, namely the genital mucosa.
• One possible mechanism of protection of the cervix is transudation of serum IgG into cervical secretions.
Cervico-Vaginal Secretion Collection
Collection of CVS and antibodies extraction protocols–Protocols described by Castle et al, 2004–Validation in collaboration with NCI
Collection of CVS–Merocel® Ophthalmic Sponges–30 seconds contact in the cervix–2 sponges per subject
– (2nd sponge = back-up sample)
Presentation TF Schwarz, ACOG 2007
Log ratio (anti-HPV-16/total IgG) in serum Log ratio (anti-HPV-18/total IgG) in serum
Log
ratio
(ant
i-HP
V-1
6/to
tal I
gG) i
n C
VS Anti-HPV-16
Log
ratio
(ant
i-HP
V-1
8/to
tal I
gG) i
n C
VS
n = 62 R = 0.895
0.2
0.4
0.6
0.8
1
1.2
1.4
0 0.2 0.4 0.6 0.8 1 1.2 1.4
Anti-HPV-18n = 51
R = 0.879
0.2
0.4
0.6
0.8
1
1.2
1.4
0 0.2 0.4 0.6 0.8 1 1.2
Correlation between CVS and serum antibodies in combined age groups 15-55 years
Presentation TF Schwarz, ACOG 2007
High Correlation between CVS and serum antibodies according to age group
Log ratio (anti-HPV-16/total IgG) in serum
Log
ratio
(ant
i-HP
V-1
6/to
tal I
gG) i
n C
VS
Age groups
Anti-HPV-16
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2
15-25 years26-45 years46-55 years
Presentation TF Schwarz, ACOG 2007
Age groups
Anti-HPV-18
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2
15-25 years26-45 years46-55 years
Log ratio (anti-HPV-18/total IgG) in serum
Log
ratio
(ant
i-HP
V-1
8/to
tal I
gG) i
n C
VS
High Correlation between CVS and serum antibodies according to age group
Presentation TF Schwarz, ACOG 2007
The Value of Vaccinating Mature Women
• Continued risk regardless of age or lifestyle• Continued prevalence of disease• Infections continue to occur• Persistent infections which progress to
CIN 3+ more likely• Time to see reduction in cancers is
accelerated by vaccinating all ages of women
Continued Risk• Lifetime number of sexual partners of the
woman and her partner is stronglyassociated with HPV acquisition.
• Women continue to have new partners.
• Her partner continues to have new partners.
Burk et al.JID 1996 Kjaer et al. Int J Cancer 1991; Bergman et al. J Reprod Med 1992Bosch et al. J Natl Cancer Inst 1996; Castellsagué et al. JID 1997Beral et al, Lancet 1974; Skegg et al. Lancet 1982Tarkowski et al. JID 2004; Wang SS et al. Br J Cancer 2003Wheeler et al. Sex Transm Dis 1993; Johnson et al.Lancet 2006; Barrasso et al. NEJM 1987
Prevalence
Age (yrs) n % Prevalence 95% CI
14-19 652 33.9 24.5 19.6-30.5
20-24 189 9.8 44.8 36.3-55.3
25-29 174 9.1 27.4 21.9-34.2
30-39 328 17.1 27.5 20.8-36.4
40-49 324 16.9 25.2 19.7-32.2
50-59 254 13.2 19.6 14.3-26.8
All ages 1921 100 26.8 23.3-30.9Dunne et al . JAMA. 2007;297:813-819
Anogenital HPV DNA Prevalence in US Women between 14-59 years
All ages are infected with LR and HR HPV
Infection with HPV is a lifetime risk, not restricted to one age group
% H
R H
PV +
AgeCubie J Med Virol 1998; Schiffman and Krüger Kjaer, JNCI 2003;
Rintala MAM, CID 2005; Smith E, STD 2004, Int J Ob Gyn 2004;
Bandyopadhyay S As Pac J Ca Res 2003; Stone 2005, Dunne 2005
Prevalence Of Oncogenic Anogenital HPV Varies Through Lifetime
0
5
10
1520
25
30
35
40
Birth - 10
11 - 15
16 - 20
21 - 25
26 - 30
31 - 35
36 - 40
41 - 45
46 - 50
51 - 55
56 - 60
61 - 65
66 - 70
71 - 75
76+
Pattern of HPV prevalence in N and S America
Pattern of HPV prevalence in Europe/Africa/Asia
Infections Continue to Occur
Repeat HPV type specific natural infections occur equally in women after 5-7 years FU regardless of type specific serostatus
00.30.60.91.21.51.82.12.42.7
3
HPV 16 HPV 18 HPV 31
Seronegative Seropositive
Rat
e of
type
spe
cific
H
PV in
fect
ions
(%)
Antibody levels from natural infection are insufficientinsufficient to protect against new HPV
infections of the same type
Viscidi RP et al. CEBP. 2004; 13:324-327
10,049 women Guanacaste, Costa Rica NCI Study
92/
5360
19/
1492
37/
5384
16/
156543/
545911/
1490
Women initially HPV-
Women initially HPV+
HPV- HPV+ HPV- HPV+
21 79 3 3 1 3.7 (1.3–10.2)
31 94 3 1 0 3.1 (1.1–8.7)
41 94 3 3 0 3.1 (1.1–8.7)
51 360 11 1 0 3.0 (1.7–5.2)
Total 627 20 8 1 3.1 (2.0–4.7)
3-yearAcquisition rate
(%)
Age(baseline)
Grainge MJ et al. Emerg Infect Dis 2005;11:1680–5.
Mature women continue to acquire new HPV-16 infections at 1% per year
Women initially HPV-
Women initially HPV+
HPV- HPV+ HPV- HPV+
21 77 2 6 1 2.5 (0.7–8.8) –
31 89 5 3 1 5.3 (2.3–11.9) –
41 95 3 2 0 3.1 (1.0–8.6) –
51 352 14 5 0 3.8 (2.3–6.3) –
Total 613 24 16 2 3.8 (2.5–5.5) 88.9 (67.1–96.9)
3-yearAcquisition rate
(%)
3-yearClearance rate
(%)
Age(baseline)
Grainge MJ et al. Emerg Infect Dis 2005;11:1680–5.
Mature women continue to acquire new HPV-18 infections at 1% per year
Persistent Infections Likely to Progress to CIN 3 and Cancer
HPV 16+
HPV 18+Non HPV 16/18 oncogenic HPV+
Oncogenic HPV-
Khan MJ et al. J Natl Cancer Inst 2005;97:1072–9.
Total study population = 20,514Study population >30 yrs old =13,229
Persistence of HPV 16/18 infections leads to
CIN 3+ in women ≥ 30 years
Khan MJ et al. J Natl Cancer Inst 2005;97:1072–9.
Total study population = 20,514Study population >30 yrs old =13,229
Persistence of HPV 16/18 infections leads to
CIN 3+ within 10 years in women ≥ 30 years
For all ages of women:
17% of persistent HPV 16 infections progress to CIN 3+14% of persistent HPV 18 infections progress to CIN 3+
For women
20% of persistent HPV 16 infections progress to CIN 3+15% of persistent HPV 18 infections progress to CIN 3+
≥ 30 years:
Time to Reduce Cervical Cancer
Impact on HPV 16/18-related CERVICAL CANCER INCIDENCE
with 16/18 vaccine and continued lifetime boosters starting at age 12
0
1
2
3
4
5
0 10 20 30 40
Years Since Vaccination
Inci
denc
e pe
r 10
0,00
0
No Vaccination
12-yo females
12-yo females + femalescatch up
Elbasha EH, Dasbach EJ, Insinga RP. Emerg Infect Dis. 2007 Jan;13(1):28-41.
Impact on HPV 16/18-related CIN 2/3 INCIDENCE with 16/18 vaccine
and continued lifetime boosters starting at age 12
Elbasha EH, Dasbach EJ, Insinga RP. Emerg Infect Dis. 2007 Jan;13(1):28-41.
0
20
40
60
80
100
0 10 20 30 40
Years Since Vaccination
Inci
denc
e pe
r 10
0,00
0
No Vaccination
12-yo females
12-yo females+females catch up
The Value of Vaccinating Mature Women
• Continued risk regardless of age or lifestyle• Continued prevalence of disease• Infections continue to occur• Persistent infections which progress to
CIN 3+ more likely• Time to see reduction in cancers is
accelerated by vaccinating all ages of women
Conclusions• HPV 16 and 18 L1 VLPs with the AS04 adjuvant
system induce – higher antibody titers than with an alum adjuvant
alone– long term B cell memory – robust antibody titers well above natural infection
titers for at least 5.5 years– robust antibody titers for all ages of women
• Cervical cancer prevention will be most effective when mature women are also vaccinated