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Vaccines to Prevent Ocogenic HPV Infections John Schiller, National Cancer Institute, NIH, USA HPV and Cancer Prophylactic HPV Vaccine Implementation Issues Worldwide incidence and distribution of cancers attributable to HPV Cervix had approximately 450,000 HPV and total cases Oropharnyx has 50,000 HPV cases and 100,000 total cases Anus has 40,000 HPV and 50,000 total cases Oral has 25,000 HPV and 250,000 total cases Larynx has 20,000 HPV and 150,000 total cases Vulva has 10,000 HPV and 30,000 total cases Penis has 10,000 HPV and 30,000 total cases JA Kahn, NEJM, 2009;361:271 The HPV Life Cycle Precursor lesions for cervical cancer Initiation Site of
Female reproductive Tract Anatomy & Histology Transformation Zones in Other HPV Cancers Anal cancer also occur at the transformation zone. HPV Infections of the vulvar, vagina and penis are common. Cancers at these site are relatively rare. They lack a transformation zone. Cervical Cancer Develop at the Transition Zone Between Squamous and Columnar Epithelium Time Line of Cervical HPV Infections And Progession to Cervical Cancer Lifetime incidence of genital HPV infection >80% in U.S.
Most infections clear spontaneously, eliminating cancer risk for that infection.
Persistent infection with a high-risk HPV, especially HPV16 or 18, is the single most important risk factor for progression to precancer and cancer. 5 Most Common HPV Types in Squamous Cell Carcinoma - By Region foot
warts genital warts EV cutaneous,
mostly asymptomatic HPV16 HPV6 HPV11 HPV18 HPVs Cause A Variety of Proliferative Diseases Therapeutic vs Prophylactic HPV Vaccines Therapeutic vaccine attractive since Cervical CA develops slowly from well defined and routinely identified viral lesions. E6 and E7 expressed.
Approved vaccines against other viral infections are preventive (based on neutralizing antibodies), not therapeutic (based on cell mediated immune responses).
We initially concentrated on Prophylactic Vaccines Live Attenuated Viruses Are Not Suitable For an HPV Prophylactic Vaccine • Papillomavirus cannot be efficiently grown in cultured cells • The viral genomes contain oncogenes • Virion protein-based subunit vaccines are preferable, if they could efficiently induce neutralizing antibodies. Papillomaviruses Encode Two Structural Proteins L1: the major structural protein. Each viral particle has 360 copies in 72 pentamers.
L2: the minor structural protein. Up to 72 copies per particle. L1 L1 L1 L1 L1 L2 Papillomavirus Particle Key To the Development of L1 Vaccines
IM injection of virions, but not denatured L1 or L1 pepptides, induced protection from experimental infection in animal models. Generating an immunogen with conformationally correct L1 was critical.
HPV Virion L1 coding region
Prophyactic HPV Vaccines Are L1 Virus Like Particles (VLPs) L1 Insertion in Baculovirus Expression Vector Production in Insect Cells Spontaneous assembly of L1 into VLPs Induce high titers of virion neutralizing antibodies Two Distinct HPV VLP Vaccines Were Developed Commercially GlaxoSmithKline: HPV16 Cervarix HPV18 ASO4 Adjuvant (Aluminum + MPL) Made in insect cells Merck: HPV16 Gardasil HPV18 HPV6 HPV11 Aluminum Adjuvant Made in yeast IM Injections at 0, 1 or 2, and 6 months Efficay Endpoints in Clinical Trials Cervical intraepithelial neoplasia (CIN): CIN1, CIN2, CIN3Cervical adenocarcionoma in situ (AIS) External genital lesions (EGL): genital warts, vulvar/vaginal dysplasia-Gardasil Incident or persistent vaccine type infection: cervical HPV DNA Most analyses restricted to HPV types in the vaccines Endpoint for Licensure:CIN2+ from incident infection by vaccine type HPV Vaccine Phase III Trial Outcomes: Interim ATP Analyses - Vaccine Types Only Young women without prior infection with vaccine included HPV types HPV Vaccine Efficacy Trial Outcomes Efficacy measured as prevention of incident (new) infection and disease caused by the HPV types in each vaccine (fully vaccinated women, 16-26 years old) ●Garland (2007) used the 6/11/16/18 vaccine and using CIN2/3, AIS, GW, Vin and VAIN as endpoints found that the vaccine efficiency was 100% (94-100). ●Kjaer (2009) used the 6/11/16/18 vaccine and using CIN2/3, AIS, VIN2/3 and VAIN2/3 as endpoints found that the vaccine efficieny was 98% (93-100). ●Paavinen (2009) used the 16/18 vaccine and using CIN2/3 as an endpoint found that the vaccine was 98% efficient (88-100).
Efficacy of Less than Three Doses of Cervarix NCI’s Costa Rica Trial Protection from 12 mo. Persistent HPV16/18 Infection* ●With 3 doses the vaccine efficacy is 80.9% (70.1-89.8). ●With two doses the vaccine efficacy is 84.1% (50.2-96.3). ●With one dose the vaccine efficacy is 100% (66.5-100). Cumulative Incidence of All CIN2+ Regardless of HPV DNA or Sero-Status at Entry Intention to Treat Cohort
PATRICIA - Cervarix Study Placebo Cervarix Gardasil Approval Specifics US FDA approved for 9-26 yr old females in June ‘06 European Union and Australia approved for: 9-26 yr old females 9-15 yr old boys Approval in 9-15 yr old girls and boys was based on immunogenicity bridging studies not efficacy Cervarix Approval Specifics E.U.: 10-25 yr old females in 2007 Australia: 9-45 yr old females in 2007 U.S. FDA approved for 10-25 yr old females in Oct. ’09 Approval in 9-15 yr old girls and 26-45 yr old women was based on immunogenicity bridging studies not efficacy ATP Analysis of PATRICIA (Cervarix): Vaccine Efficacy Against 6 Months Persistent DNA HPV-16/18 93.8% HPV-31 78.7% HPV-33 45.7% HPV-45 75.7% HPV-52 7.8% HPV-58 1.8% HR except 16/18 12.1% Any HR type 25.0% HPV11 HPV16 HPV35 HPV18 Neutralize Ab Response to L1 is Predominately Type-Specific Anti-L1 antibodies are generated against conformational surface loops Percentages of cervical cancer cases arrributed to the most frequent HPV types in all world regions HPV-16 54.6% HPV-18 15.8% HPV-33 4.4% HPV-45 3.7% HPV-31 3.5% HPV-58 3.4% HPV-52 2.5% HPV-35 1.8% HPV-59 1.1% HPV-56 0.8% HPV-51 0.7% HPV-39 0.7% HPV-73 0.5% HPV-68 0.5% HPV-82 0.2% Potential Impact of the Vaccines in the US 10,000,000 have subclinical HPV infection in US 1,400,000 have low-grade dysplasia 300,000 have high-grade dysplasia 10,000 have cancer
Efficacy of Gardasil in Mid-Adult Women Ages 24-45 Against Vaccine Types Persistent infection, CIN or EGF has 88.7% efficiency (78.1-94.8) Persistent infection has 89.6% efficiency (79.3-95.4) CIN-any grade has 94.1% efficiency CIN 2/3 has 83.3% efficiency (37.6-99.6) EGF has 100% efficiency (30.8-100)
Rate Reduction in Treatment Related to Any HPV Type in Gardasil-Vaccinated Mid-Adult Women Coposcopy has a 4.7% rate reduction (-9.5-17.1) Biopsy has a 3.7% rate reduction (-11.0-16.4) Definitive therapy has a 8.8% reduction (-16.7-28.8) Gardasil Prevents Genital Warts in Young Men Ages 16-26 External genital lesions HPV-6, 11, 16, 28 90.4% Any type 83.8% AIN-any grade HPV-6, 11, 16, 18 77.5% Any type 54.9% HPV-58 1.8% AIN 2/3 74.9% Persistent anal infection Any HPV- 6, 11, 16, 28 94.9% Number of Events Months in Study 77.5 %
Efficacy Gardasil: Time to HPV6/11/16/18-Related AIN in MSM: Per Protocol Efficacy Population Anal and Cervical HPV16/18 VE Among Women w/out Evidence of Cervical HPV DNA at Vaccination Costa Rica Trial of Cervarix Efficacy at Study Exit Against HPV DNA by Site Anus: The HPV arm had 0.8% HPV 16/18 prevalence. Anus: The control arm has 4.9% HPV 16/18 prevalence. The HPV 16/18 VE was 83.6% (66.7-92.8). Cervix: The HPV arm had 1.0% HPV 16/18 prevalence. Cervix: The control arm has 8.2% HPV 16/18 prevalence. The HPV 16/18 VE was 87.9% (77.4-94.0). p = 0.55 December 2010
AIN in MSM Study has led to FDA approval of
Gardasil for the prevention of anal cancer and AIN
in both men and women.
Gardasil approved for Genital Warts in 2009 United States: Incidence and Distribution of Cancers Attributable to HPV Infection ●There are about 10,000 cases of cervix cancer and all are HPV cases ●There are about 3,000 cases of vulva/vagina cancer and 50% are HPV cases ●There are about 3,000 cases of anus cancer and 90% are HPV cases ●There are about 500 cases of penis cancer and 20% are HPV cases ●There are about 8,000 cases of oropharynx cancer and all are HPV cases Clinical Trial Evidence for Vaccine Efficacy Against Infection/IN at Site. The vaccine is effective against cervix cancer, vulva/vagina cancer, anus cancer and penis cancer but not oropharynx cancer Consistency of Antibody Response to VLPs Percent of Women Serocoverting to Individual HPV VLPs in Merck Quadravalent VLP Vaccine Gardasil* HPV6 99.8% HPV11 99.8% HPV16 99.8% HPV18 99.5% *4666 women vaccined 3 times by intramuscular injection 0 7 12 18 25 33 39 45 51 57 63 69 75 Month: Month:
0 7 12 18 25 33 39 45 51 57 63 69 75 HPV16 VLP ELISA HPV16 Neutralization Assay Durability of Antibody Response to Cervarix Duration of Protection
Strong Protection through the six years since the
studies began. No evidence for increase numbers
of breakthrough infections.
Y Y Y
Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y Y How Could IM Injection of a VLP Vaccine Induce a Protective Ab Response at the Cervix? Doorbar, J Clin Virol 32:7-15, 2005 Virus Producing Non-productive Non-productive Decreasing Epithelial Differentiation T Cell Responses To L1 Unlikely to Induce Regression:Virion Protein Expression is Lost During Progression VLP Vaccines Don’t Influence Prevalent Infection NCI/Costa Rican HPV16/18 VLP Vaccine Trial : Rate of HPV-16/18 DNA Clearance by Treatment Arm VE = 5.8% VE = -5.4% Conclusions: HPV VLP Vaccine Efficacy • VLP vaccines are highly effective at protection against a spectrum of anogenital HPV endpoints from incident infection to high grade precancer. • Gardasil is also highly protective against genital warts in women and men. • Protection is type-restricted, consistent with protection being antibody mediated. • Duration of protection is unknown, but strong protection at 6 years, after antibody levels have reached a plateau, is very encouraging Global HPV Vaccine Licensure Status March 2010 Who Should Be Vaccinated? In descending order of importance: 10-14 year old girls - the ultimate target group since they have not yet been exposed to these sexually transmitted viruses Sexually active women - since many may not yet been exposed to at least one of the vaccine types; may reduce transmission - increase herd immunity Adolescent boys and men - only 8% of HPV cancer in men; may be small impact on herd immunity if coverage of women high; most models suggest male vaccination would not be cost effective Acquisition of Genital HPV Infection in Young Women With Their First Sexual Partner
Who Should Be Vaccinated? In descending order of importance: 10-14 year old girls - the ultimate target group since they have not yet been exposed to these sexually transmitted viruses Sexually active women - since many may not yet been exposed to at least one of the vaccine types; may reduce transmission - increase herd immunity Adolescent boys and men - only 8% of HPV cancer in men; may be small impact on herd immunity if coverage of women high; most models suggest male vaccination would not be cost effective From: Tom Wright, HPV Today, February 2008 Recommendations for HPV Vaccination in Females as of October 2007 Who Should Be Vaccinated? In descending order of importance: 10-14 year old girls - the ultimate target group since they have not yet been exposed to these sexually transmitted viruses Sexually active women - since many may not yet been exposed to at least one of the vaccine types; may reduce transmission - increase herd immunity Adolescent boys and men - only 8% of HPV cancer in men; may be small impact on herd immunity if coverage of women high; most models suggest male vaccination would not be cost effective October 2011 CDC Advisory committee recommends that boys ages 11-12 be routinely vaccinated with Gardasil, with catch up through age 26. 59% 2004 2005 2006 2007 2008 2009 2004 2005 2006 2007 2008 2009
Genital Wart Time Trends in Australian Women 2004-2009
2004 2005 2006 2007 2008 2009
2004 2005 2006 2007 2008 2009
28 % 39 %
Donovan et al. , Lancet Infect Dis, 2010 Genital Wart Time Trends in Australian Men 2004-2009 Outstanding Implementation Issues High Cost of the Vaccine: Gardasil is $120 per dose What ages to start vaccinating What age is too old for catch up vaccination Acceptance of an STI vs Cevical Cancer vaccine (but tens of million doses of the vaccines sold, even in the US) Delivery of 3 IM doses to early adolescents Effects of vaccine on Cervical Ca screening recommendations and compliance 49%* 32%* Trends in U.S. Vaccination Rates: Ages 13-17 Yrs School-Based Vaccination Programs Work: The UK Experience In Scotland 90% of the 12-13 year old girls are vaccinated in school In Scotland 90% of the 17-18 year old girls are vaccinated in school In England 80% of the 12-13 year old girls are vaccinated in school In England 30% of the 17-18 year old girls are vaccinated Outstanding Implementation Issues High Cost of the Vaccine: Gardasil is $120 per dose What ages to start vaccinating What age is too old for catch up vaccination Acceptance of an STI vs Cevical Cancer vaccine (but >30 million doses of Gardasil sold) Delivery of 3 IM doses to early adolescents Effects of vaccine on Cervical Ca screening recommendations and compliance
We Can’t Give Up Screening The vaccine won’t help women with established infections/lesions. If type restricted, the current VLP vaccines could not prevent ~20-30% of cervical cancers. Need to convince vaccinated women to comply with existing screening programs. A shift to an HPV-Based cervical cancer prevention strategy 15 y.o. 30 y.o. 45 y.o. HPV Precancer Cancer Age Rate
Key Collaborators National Cancer Institute Doug Lowy Past Members of the Lab: Reinhard Kirnbauer Richard Roden Diana Pastrana Present Members of the Lab Chris Buck Susana Pang Patricia Day Cindy Thompson Jeff Roberts Rhonda Kines Outside Clayton Harro: Johns Hopkins University- Baltimore Denise Nardelli: Universitaire Vaudois - Lausanne