the relevance of the as04 adjuvant system to cervical ... · into virus-like particles...

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