Prophylactic HPV Vaccines Margaret Stanley Department of Pathology Cambridge
8kb double stranded DNA viruses, absolutely host and tissue specific, Can t grow virus in tissue culture Classified by genotype not serotype
Benign Mucosal HPV-Associated Disease Laryngeal papillomas Condylomata acuminata HPV 6, 11 HPV 6, 11
Anogenital cancer and AIN Neoplastic HPV-Associated Genital Disease Invasive cervical cancer and CIN VIN (Vulval intra-epithelial neoplasia) and Vulval cancer HPV 16, 18 HPV 16, 31, 33, 35, 52, 58, HPV 18, 39, 45, 59 HPV 56, 66. HPV 51 HPV 16,31, 33
ALL WORLD REGIONS COMBINED 16 53.5 18 17.2 45 6.7 31 2.9 33 2.6 52 2.3 58 2.2 35 1.4 59 1.3 WOMEN > 15: 2,013,133,000 N CASES per year: 469,723 56 1.2 51 1.0 39 0.7 68 0.6 73 0.5 82 0.3 Other 1.2 X 4.4 0 20 40 60 80 100 53.5% 70.7% 77.4% 80.3% 82.9% 85.2% 87.4% 88.8% 251,199 80,859 31,549 13,678 12,134 10,929 10,242 6,570 6,137 5,769 4,641 3,211 2,714 2,339 1,350 5,632 20,769
Infection with one of the high risk genital HPVs is the major risk factor for cervical cancer HrHPV DNA sequences are detected in 90-100% of cancers HrHPV DNA sequences are detected in 90% of high grade CIN or SIL Case control studies OR s > 100 Prospective studies - HrHPV infection causes CIN HrHPVs immortalise primary genital keratinocytes
cervical intra-epithelial neoplasia-cin Normal CIN 1 CIN 3 Transient genital HPV infections very common in young sexually active women Most are subclinical and resolve Most lesions are low grade CIN 1 and most resolve A minority of women develop persistent infections with focally high levels of DNA Some persistent infections with hrhpvs progress to CIN2/3 Some CIN2/3 progress to invasive carcinoma
Natural Course of Genital HPV Infection HrHPVs 12-18months Time LrHPVs 4-9months infection First Lesion Immune Response CMI Seroconversion Antibody to L1 Virological clearance DNA-ve DNA-ve Productive viral infection, DNA+ve low grade lesions Viral persistence DNA+ve LSIL/HSIL
Detectable Serum Antibodies to HPV: Limitations as Marker of Infection or Natural Immunity Antibody responses to HPV infection slow and weak and vary with HPV type 1 In a study of 588 women with HPV 16, 18, and 6 infections, median time to seroconversion was ~12 months after incident infection. Did not occur in all women Only 54% 69% seroconverted within 18 months of incident infection. 1. Carter JJ, Koutsky LA, Hughes JP, et al. J Infect Dis. 2000;181:1911 1999.
Why are antibody responses so poor in natural HPV infections? No viraemia HPV does not lyse keratinocytes no inflammation no pro-inflammatory cytokines poor activation of Langerhans cells and stromal dendritic cells Free virus particles are shed from mucosal surfaces with poor exposure to APC
Why might vaccines generating neutralising antibody be effective prophylactically? Systemic immunisation with infectious CRPV did not induce visible papillomas generated serum neutralising antibody Immunised rabbits were protected against viral challenge Shope RE 1937 Immunisation of rabbits to infectious papillomatosis J Exp Med 65 607-24
Neutralising antibodies are directed against the L1 capsid protein Generation of neutralising antibody requires the tertiary or native structure of the protein these viruses cannot be grown in bulk in tissue culture
HPV 16 L1 VLPs - Virus like particles Virions Express the L1 gene in a suitable vector (yeast, baculovirus), the protein self assembles into a macromolecular structure a virus like particle -that is geometrically and antigenically almost identical to the native virion
Vaccine profiles HPV 16/18 vaccine Cervarix HPV 6/11/16/18 vaccine Gardasil Manufacturer GlaxoSmithKline MSD Volume Per dose 0.5 ml Per dose 0.5 ml Adjuvant AS04: Al(OH) 3 500 µg MPL 50 µg Aluminium salt 225 µg L1 HPV 6 20 µg Antigens L1 HPV 16 20 µg L1 HPV 11 L1 HPV 16 40 µg 40 µg L1 HPV 18 20 µg L1 HPV 18 20 µg Expression system Hi-5 Baculovirus Yeast Schedule Intramuscular 0, 1, 6 mths Intramuscular 0, 2, 6 mths Licence application made licensed
Bivalent Vaccine Phase II Data
Efficacy data (HPV-001) Cervarix HPV 16 and/or 18 Cervical Protection Prevention of HPV-16/18 related infection & lesions Vaccine efficacy 100 95 90 85 80 75 70 65 60 55 50 ATP Incident Persistent cytology CIN lesions D. Harper et al, Lancet, 2004, 364 : 1757-65
Quadrivalent vaccine Phase III Data
HPV 16/18-Related Cervical Cancer HPV-Naïve MITT Population Endpoint HPV vaccine Placebo % 95% C.I cases cases Efficacy n=9342 n=9400 HPV 16/18-related CIN 3 or AIS HPV 16/18-related CIN3 HPV 16/18-related AIS 0 0 0 52 47 9 100 100 100 93, 100 92, 100 49, 100 Mean follow up 2 years Subjects are counted once per applicable row. www.fda.gov/ohrms/dockets/ac/06/slides/2006-4222s-index.htm
Gardasil efficacy against external genital disease HPV type Vaccine Placebo cases:2261 cases:2279 HPV 6 0 23 HPV 11 0 10 HPV 16 0 10 HPV 18 0 3 Mean 20 months follow up www.fda.gov/ohrms/dockets/ac/06/slides/2006-4222s-index.htm
Some frequently asked questions Immune correlates and duration of protection Is there cross protection Who should we immunise Must the vaccine be given pre-exposure to virus If we control types that are currently the most common, will other rarer types take their place
Quadrivalent HPV Vaccine Anti-HPV Immunogenicity, Neutralizing Ab In a double-blind, placebo-controlled, dose-ranging study of quadrivalent HPV (types 6, 11, 16, 18) L1 VLP vaccine. Geometric Mean Titer* With 95% CI mmu/ml (Log Scale) 1000 HPV 6 100 10 1 10000 1000 100 10 ** * Vaccination HPV 16 ** * Vaccination 71218243036 5460 1000 HPV 11 100 10 1 100 10 1 ** * Vaccination 1000 HPV 18 ** * Vaccination 71218243036 5460 Time Since Vaccination 1 (Months) *clia=competitive Luminex immunoassay Vaccine (Per Protocol)
Bivalent vaccine 5 year antibody concentration in vaccinees and placebos Harper et al 2006 Lancet 367 1247-55
Quadrivalent HPV Vaccine Yields Higher Neutralizing Anti-HPV Antibodies in Baseline Seropositive Subjects Geometric Mean Titer (mmu/ml) Log 10 Scale 3000 2000 1000 100 10 1 Vaccine: naive recipient Placebo: naive recipient Vaccine: seropositive and PCR negative recipient Placebo: seropositive and PCR negative recipient 0 7 12 18 30 42 48 Months These results suggest that women who were baseline anti-hpv positive had developed a booster response to the vaccination.
Demonstration of Immune Memory with an Antigen Challenge at Month 60 1 Anti-HPV response (GMT Levels with 95% CI [log 10 scale]) 10,000 1000 100 10 HPV 16 Placebo (Sero ( ) and PCR ( )) n=70 0 2 3 6 7 12 18 24 30 36 54 Months Vaccination on day 0, at two and six months Immune challenge at 60 months Quadrivalent HPV Vaccine n=78 60 61 60+1 week Immune memory demonstrated after immune challenge Similar results seen with HPV 18, 6, and 11 *In subjects naïve to the relevant HPV type from day 1 through month 60 1. Data on file, MSD.
Is there cross-protection? Some suggestion for cross-protection against infection against HPV 45 and 31 after vaccination with Cervarix Harper etal Lancet April 6 th 2006 Cross reacting and cross-neutralising antibodies to HPV 45,31,58 and 52 generated after immunisation with Gardasil Titres of these cross-reacting antibodies are 1-2 logs lower than the dominant type specific neutralising antibody Smith JF et al IPV Prague Sept 3 2006 Abstract PL 1-6
Prevention of Other High Risk Incident HPV Infections ITT Group Bivalent Vaccine Cross Protection HPV 45 (related HPV 18) 90% 94% 18 45 94% (95% CI: 63-100 P/V: 17/1 events) HPV 31 (related HPV 16) 88% 16 55% 31 55% (95% CI: 12-78 P/V: 30/14 events) Courtesy Dr Diane Harper
Evidence of Cross-Reacting Antibodies - GARDASIL Gardasil Total IgG Geometric Mean End Point Titers 100000 GMT (Total IgG End Point Titers) 10000 1000 100 10 HPV 31 HPV 45 HPV 52 HPV 58 HPV 16 HPV 18 1 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (months)
Evidence of Cross-Neutralization GARDASIL Gardasil Antibody Cross-Reactivity and Cross-Neutralization Profile at Peak Antibody Titers (Month 7) 10000 GMT End point dilution titers 1000 100 10 GMT of Diultion Achieving 50% Neutalization Effect 18 Total IgG 45 Total IgG 18 50% NE 45 50% NE 1 18 Total IgG 45 Total IgG 1 18 Neutalization 45 Neutalization Immuno Assay Test
Quadrivalent HPV Vaccine Phase III Adolescent Immunogenicity Study Neutralizing Anti-HPV GMTs * at Month 7 1500 1500 1000 1000 500 500 0 Anti-HPV 6 (HPV 6 mmu/ml) 0 Anti-HPV 11 (HPV 11 mmu/ml) 8000 6000 4000 2000 0 1500 1000 500 0 Anti-HPV 16 (HPV 16 mmu/ml) Anti-HPV 18 (HPV 18 mmu/ml) Females 10 15 Years of Age Males 10 15 Years of Age Females 16 23 Years of Age *GMT = geometric mean titers 1. Block SL, Nolan T, Sattler C, et al. Pediatrics. 2006: in press.
Age Specific Neutralizing HPV-6 Antibodies 1 Month Post-Vaccination 1 PPE population* Neutralizing anti-hpv 6 GMTs at month 7 Serum clia GMT with 95% CI, mmu/ml 1600 1500 1300 1100 900 700 500 Immunogenicity Bridge Males + Females Females Only Efficacy Program 1. Data on file, MSD. 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Age at Enrollment (Years) *Inclusive of five study protocols; all GMTs measured using clia
Some frequently asked questions Immune correlates and duration of protection? Is there cross protection Who should we immunise Must the vaccine be given pre-exposure to virus? If we control types that are currently the most common, will other rarer types take their place?
infection Natural Course of Genital HPV Infection DNA-ve Sero-ve Incubation (1-6 Mo.) First Lesion Immune Response Active Growth (3-6 Mo.) Host Late Stage Containment (3-6 Mo.) DNA+ve Sero-ve Seroconversion Average time 9mo DNA-ve Sero+ve DNA+ve Sero+ve Sustained clinical remission Persistent or recurrent disease
Prophylactic HPV L1 VLP vaccines Efficacy Immunogenic Duration of protection Safe >90% for persistent infection 100% for disease (5 years post vaccination) in subjects naïve for vaccine HPV types high antibody concentrations up to 1000x > than in natural HPV infection vaccine induced antibody levels maintained over 5 years no vaccine related serious adverse events identified in the trials to date (70,000 women)