1
| 1
Dengue: About the Disease and Emerging Vaccines
Gustavo Dayan, MD
Vaccine Preventable Diseases: Policy, Practices, Preparedness
New York City, NY
July 23, 2012
| 2
Overview
● Dengue
● Virus
● Disease
● Public health burden
● Vaccines in development
● Live virus
● Inactivated
● Subunit
● DNA/vector
● Sanofi Pasteur dengue vaccine
● Clinical development
● Safety
● Immunogenicity
| 3
•Flavivirus (YF, JE, TBE, WN)
•Positive sense single stranded RNA (~11kb) that
codes for 3 structural proteins & 7 non-structural
proteins
• Four closely related, but
antigenically distinct serotypes (DEN 1-4)
- Immunity: serotype specific and prolonged - Cross protection: little and short duration - Some variants more virulent and with greater epidemic potential
Prot é ines de structure 5 ’ Non
Codant 3 ’ Non
Codant
Prot é ines non stucturales NS Prot é ines de structure 5 ’ Non
Codant 3 ’ Non
Codant
Prot é ines non stucturales NS
NS3 C E NS1 NS2A NS2B NS4A NS4B NS5
Structural
Proteins
5’ NC 3 ’ NC
prM
Non Structural Proteins Zhang et al., 2003,
Dengue Virus
Source: Zhang Structure of Dengue Virus Cell, 2002;(108):717–725.
| 4
Dengue – Clinical Stages
● Asymptomatic Dengue Virus Infection
● Non-specific Febrile Illness
● Dengue Fever (DF) ● High fever for 5-7 days, with headache,
myalgia
● Usually followed by 2-3 weeks of debilitating fatigue
● Dengue Hemorrhagic Fever (DHF) ● DF with vascular permeability,
● Primarily in children, with a peak around 5-9 years old
● In outbreak situations, DHF is seen in all ages
● Case fatality rate
• 20% without treatment
• <1% with treatment
● Dengue Shock Syndrome (DSS)
DSS
DHF
Dengue Fever
Undifferentiated Fever
Asymptomatic
| 5
Courtesy Dr. S. Kalayanarooj
Adolescent diagnosed with dengue fever. Dengue Unit
Ratchaburi Hospital, Thailand – Feb 2011
| 6
Dengue – Public Health Burden
● Mosquito borne disease
● Aedes aegypti main vector
● Arthropod-borne viral disease with highest morbidity
and mortality
● 2.5 billion people at risk in over 100 countries
● >50 million people infected annually
● 2 million, mostly children, develop a severe form of the
disease
Source:
CDC - Outbreak Notice - Update: Dengue in Tropical and Subtropical Regions available on: http://wwwnc.cdc.gov/travel/notices/outbreak-notice/dengue-tropical-sub-tropical.htm
WHO - Dengue and dengue haemorrhagic fever, Fact sheet n
117, March 2009, available on: http://www.who.int/mediacentre/factsheets/fs117/en
2
| 7
Global Dengue Risk
Source: Simmons CP, et al. N Engl J Med. 2012;366-1423-32
| 8
Dengue in the Americas, 1980-2010
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
1,400,000
1,600,000
1,800,000
19
80
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
20
04
20
06
20
08
20
10
Y E AR
NU
MB
ER
OF
CA
SE
S
YEAR 1981 CUBA 344,203
YEAR 2002 HONDURAS 32.269 COLOMBIA 76,996 VENEZUELA 37,676 BRAZIL 780,644
YEAR 2009 ARGENTINA 26,612 BOLIVIA 84,047 MEXICO 249,763 COLOMBIA 51,543 VENEZUELA 65,869 BRAZIL 528,883
YEAR 2010 COLOMBIA 157,152 VENEZUELA 123,967 BRAZIL 1,004,392 HONDURAS 66,814 GUADELOUPE 41,100 PUERTO RICO 21,298
YEAR 1998 MEXICO 23,639 COLOMBIA 63,182 VENEZUELA 37,586 BRAZIL 535,388
Source:
Pan American Health Organization (PAHO). Number of reported cases of dengue & dengue haemorrhagic fever (DHF), Region of the Americas
Available at URL: http://new.paho.org/hq/index.php?option=com_content&task=view&id=264&Itemid=363&lang=en
| 9
Dengue Incidence in the Americas, 1980-2010
| 10
Dengue - Public Health Challenge
● WHO Neglected Tropical Diseases Group (WHA,
Geneva - May 2012)
● Targets and milestones for control of neglected tropical
diseases, 2015-2020
● To reduce dengue deaths by 50% by 2020
● To reduce dengue morbidity by at least 25% by 2020
Source: Accelerating Work to Overcome the Global Impact of Neglected Tropical Diseases - a roadmap for Implementation (WHO, May 2012)
| 11
Dengue Prevention
● Prevention relies on vector control and personal protection measures ● Difficult to enforce and maintain, expensive
● Development of a dengue vaccine is viewed as a public health priority
| 12
Virus isolation(Hotta & Kimura)
Sabin & Schelsinger2
19441943 19561944-45 1970 -’80
W. Hammon3
Sabin, Schelsinger2
US Army/Univ. Hawaii
/Univ MahidolThailand
/Fund. Rockefeller4
Attenuation
of DEN viruses
LAV DEN1-4(1st generation)
1928-1930
Blanc &
Caminopetros1
Killed & Attenuated
DEN vaccines
Construction
of chimeric
DEN4/DEN2
(2nd generation)
1990 - 2000
Bray M. et al
19915
Construction
of chimeric
YF/DEN2
Guirakhoo et al
20006 Construction
of chimeric
YF/DEN1,3,4
Guirakhoo et al
20017
Virus isolation and identification of serotypes
Dengue Vaccines
BZ 2009
1: AJTMH 1931;77:77-102 2: Science 1945;101(2634):640-642 3: Science 1960;131:1102-3 4: AJTMH 2003;69(Suppl 6):5-11
5: J Virol 1996;70:4162-6 6: J Virol 2000;74:3020-8 7: J Virol 2001;75:7290-7304
DEN3&4
ManilaDEN1 Hawaii
DEN N. Guinea
Monovalent
LAV DEN1
Killed DEN
vaccines
Simmons et al1
Virus isolation(Hotta & Kimura)
Sabin & Schelsinger2
19441943 19561944-45 1970 -’80
W. Hammon3
Sabin, Schelsinger2
US Army/Univ. Hawaii
/Univ MahidolThailand
/Fund. Rockefeller4
Attenuation
of DEN viruses
LAV DEN1-4(1st generation)
1928-1930
Blanc &
Caminopetros1
Killed & Attenuated
DEN vaccines
Construction
of chimeric
DEN4/DEN2
(2nd generation)
1990 - 2000
Bray M. et al
19915
Construction
of chimeric
YF/DEN2
Guirakhoo et al
20006 Construction
of chimeric
YF/DEN1,3,4
Guirakhoo et al
20017
Virus isolation and identification of serotypes
Dengue Vaccines
BZ 2009
1: AJTMH 1931;77:77-102 2: Science 1945;101(2634):640-642 3: Science 1960;131:1102-3 4: AJTMH 2003;69(Suppl 6):5-11
5: J Virol 1996;70:4162-6 6: J Virol 2000;74:3020-8 7: J Virol 2001;75:7290-7304
DEN3&4
ManilaDEN1 Hawaii
DEN N. Guinea
Monovalent
LAV DEN1
Killed DEN
vaccines
Simmons et al1
History of Dengue Vaccines
3
| 13
Challenges for Dengue Vaccine Development
● 4 different serotypes
● Technical difficulties
● Inter-serotype competition
● Need for balanced protection against all four serotypes
● There is no animal model for the disease
● Theoretical risk of immunoenhancement after sequential infections (antibody-dependent enhancement - ADE): need for a combined tetravalent vaccine
● No established correlates of protection – efficacy trials are needed
| 14
Dengue Vaccines in Development
● Live virus vaccines
Traditional attenuation
Recombinant
● Inactivated vaccines
● Subunit vaccines
● DNA vaccines
● Vector vaccines
| 15
Candidate Vaccines I -- Live Virus Vaccines
● Traditional attenuation
● Cell culture passages
• PDK, PRhL cells - WRAIR/GSK
Sun et al Hum Vaccin. 2009;5(1):33-40
● Recombinant ● Molecular attenuation through selective mutations and chimerization
• E.g., rDENV4- Δ30 - NIH/ University of Maryland
• Blaney et al Curr Top Microbiol Immunol 2010;338:145-58
● Insertion of dengue structural genes (prM/E) in a traditionally attenuated dengue virus
• DENV2 16681 PDK-53 vaccine strain - CDC/Inviragen
• Huang et al. J Virol 2003;77(21):11436-47
● Insertion of dengue structural genes (prM/E) in the yellow fever vaccine virus
• Yellow fever vaccine virus strain YF17D - Acambis/Sanofi Pasteur Capeding et al Vaccine 2011;29(22):3863-72
| 16
Candidate Vaccines II
● Inactivated vaccines - WRAIR/GSK Putnak et al. Vaccine 2005;23:4442-52
● Subunit vaccines
● Envelope + NS1 Ag- Hawaii Biotech/Merck Clements et al. Vaccine 2010;28(15):2705-15
● Protein DEN E Structural Subunits – Genetic and Biotecnology Center Cuba
Valdes et al. Clin Vaccine Immunol. 2011;18(3):455-9
● DNA and vector vaccines ● DNA – NMRC/WRAIR Raviprakash et al. Virology 2006;353:166-73
● Vector adenovirus - NMRC/WRAIR Raviprakash et al. J Virol 2008;82(14):6927-34
| 17
Main Candidate Vaccines in Clinical Development
Phase Developer # of
serotypes
Method Antigen Admin.
route
III Sanofi Pasteur
Tetravalent Atenuated, chimeric: DENV prME in YF vaccine virus 17D backbone
prM, E SC
II Inviragen Tetravalent Attenuated chimeric: DENV prME in attenuated DENV2 backbone
prM, E SC
I NIH (NIAID) Tetravalent DENV-4 30NT en 3’UTR deletion and chimerization
prM, E SC
I Merck Tetravalent Subunidad + Adyuvante Iscomatrix® E, NS1 IM
I NMRC Monovalent DNA (D1ME100) prM, E IM
I WRAIR Monovalent Inactivated DENV-1 Whole Virus IM
www.clinicaltrials.gov
| 18
0
2
4
6
8
10
12
14
16
18
20
Phase I Phase II Phase III
NIAID Sanofi Pasteur GSK Inviragen
AMR&MC Merck H. Biotech WRAIR
Dengue: Clinical Trials Published/ in ClinicalTrials.gov
Mainly monovalent formulations
www.clinicaltrials.gov. Ultimo acceso: Abril 2012 Guirakhoo et al. Human vaccines 2006;2(2):60-67 Morrison et al JID 2010;201:370-7 Poo et al PIDJ 2011;30(1):e9-e17 Capeding et al Vaccine 2011;29:3863-72
4
| 19
0
2
4
6
8
10
12
14
16
18
20
Phase I Phase II Phase III
NIAID Sanofi Pasteur GSK Inviragen
AMR&MC Merck H. Biotech WRAIRwww.clinicaltrials.gov. accessed: Abril 2012 Guirakhoo et al. Human vaccines 2006;2(2):60-67 Morrison et al JID 2010;201:370-7 Poo et al PIDJ 2011;30(1):e9-e17 Capeding et al Vaccine 2011;29:3863-72
Dengue: Clinical Trials Published/ in ClinicalTrials.gov
| 20
0
2
4
6
8
10
12
14
16
18
20
Phase I Phase II Phase III
NIAID Sanofi Pasteur GSK Inviragen
AMR&MC Merck H. Biotech WRAIRwww.clinicaltrials.gov. Ultimo acceso: Abril 2012 Guirakhoo et al. Human vaccines 2006;2(2):60-67 Morrison et al JID 2010;201:370-7 Poo et al PIDJ 2011;30(1):e9-e17 Capeding et al Vaccine 2011;29:3863-72
Dengue: Clinical Trials Published/ in ClinicalTrials.gov
| 21
non- st ruct ural genes C 5’ 3’
DEN
E prM
Sanofi Pasteur New Generation Dengue Vaccine
17D YF genome cl oned as cDNA
non- st ruct ural genes C E prM 3’ 5’
YF NS genes C E prM 3’ 5’
non- st ruct ural genes C 3’ 5’
E prM E prM
Dengue vi rus genome
| 22
non- st ruct ural genes C E prM 3’ 5’
Construction of CYD Dengue Vaccine
Ful l l engt h recombi nant cDNA RNA ( t ranscri pt i on)
RNA t ransf ect i on
Vero cel l s cul t ure
17 D YF replication “engine”
DEN envel ope prot ei ns
| 23
3’ 5’
3’ 5’
3’ 5’
3’ 5’
3’ 5’
17D YF virus
DNA 17 D YF vaccine virus
prM E DENV-1
WT PUO359
prM E DENV-2
WT PUO218
prM E DENV-3
WT PaH881/88
prM E DENV-4
WT 1228
Construction of CYD Dengue Vaccine
| 24
● Composition
● Live attenuated virus, tetravalent (4 vaccinal strains cultured in serum free Vero cells) 5
1 log10 CCID50 of each serotype
● Stabilizer without preservatives antibiotics or adjuvants
● Route of administration/Schedule
● Subcutaneous
● 3 injections 0 - 6 - 12 months
● Pharmaceutical form
● Powder and solvent for suspension for injection (0.5 ml)
● Indications
● Prevention of symptomatic dengue disease (from Dengue Fever to severe Dengue disease) due to serotypes 1, 2, 3 or 4
● Children and adults living in endemic areas, people working in (traveling to) endemic areas
● Priority: Endemic countries (Asia/Pacific, Latin America, Caribbean)
CYD Vaccine Characteristics
5
| 25
CYD Vaccine Clinical Development
Phase I studies
5 completed S&I studies in USA, Mexico, Philippines
Phase II studies
• 6 completed and 2 ongoing S&I studies in USA,
Australia, Latin America, Asia
• 1 ongoing PoC efficacy trial in Asia • 1 ongoing PoC co-ad. in Asia
Phase III studies
• 1 ongoing Lot-to-lot consistency in Australia
• 1 ongoing S&I study in Asia
• 2 ongoing S&I studies in Latin America • 2 ongoing efficacy studies in Asia and Latin America
• 2 ongoing co-ad. studies in Latin America
| 26
Safety Database
● Safety status as of March 28th 2012 ● Approximate Nbr of subjects who received at least one CYD dose
Over 28,000 individuals have already received at least one dose of CYD Dengue vaccine
Phase Toddlers Children Adolescents Adults Total
Phase I 0 140 71 185 396
Phase II 179 3368 474 893 4914
Phase III 839 10558 10411 1020 22828
Total 1018 14066 10956 2098 28138
| 27
● Reactogenicity profile similar to control vaccines
● No increase in reactogenicity
● In Flavivirus (FV)-immune subjects in comparison to FV naïve subjects
● After a 2nd or a 3rd dose
● In younger subjects (youngest group 2-11 years)
● No mild dengue-like syndrome observed
● Low vaccine viremia
● Similar rate of AEs and SAEs reported in Dengue vaccine group and
control
● No evidence to suggest a safety concern with the vaccine
Summary of Safety Data so far
| 28
Immunogenicity Database
● Immuno status as of March 28th ● Nbr of subjects immuno post dose 3 with unblind data available
Over 2,800 individuals have immune unblinded data after three doses of CYD Dengue vaccine
Phase Toddlers Children Adolescents Adults Total
Phase I 0 83 48 45 176
Phase II 0 576 437 245 1258
Phase III 0 659 485 290 1434
Total 0 1318 970 580 2868
| 29 29
Key Phase II Immunogenicity Results Post-Dose 3
GMTs
1
10
100
1000
CYD12 CYD22 CYD24 CYD28
GM
T
CYD12 CYD22 CYD24 CYD28
●USA ●Population
FV non inmune Adultss 18-45 y
● 101 subjects
CYD12
● Vietnam ●Population
DEN+/- y JE+/- Chldren/adults 2-45y
● 120 subjects
CYD22
●Singapore ●Population
DEN+/- Children/adults 2-45y
431 subjects
CYD28
●Peru ●Population
DEN+/- y YF+ Children 2-11 y
● 196 subjects
CYD24
% seropositive subjects
0
10
20
30
40
50
60
70
80
90
100
CYD12 CYD22 CYD24 CYD28
Ta
sa d
e s
ero
po
siti
vid
ad
(>
= 1
0l/d
il)
Seropositiviy ≥ 10
Serotype 1 Serotype 2 Serotype 3 Serotype 4
| 30
Summary of Immunogenicity Data so far
● Balanced immune response against all 4 serotypes after 3
doses of tetravalent Dengue vaccine
● Stepwise increase of seropositivity rates against each
serotype
● Higher immune responses observed in children
● Higher titers in subjects with previous flavivirus vaccination
● Higher titers in subjects previously exposed to wild type
dengue
6
| 31
Efficacy Clinical Trials
CYD15 Expanded Efficacy Study
Latin America
• Countries: Colombia, Mexico, Honduras,
Puerto Rico, and Brazil
• Age group: 9-16 years
• N subjects: ~20,000
CYD14 Expanded Efficacy Study
Asia
• Countries: Thailand, Indonesia, Malaysia,
Viet Nam, Philippines
• Age group: 2-14 years
• N subjects: ~10,000
CYD23 First Efficacy Study
• Country: Thailand
• Age group: 4-11 years
• N subjects ~4,000
| 32
Conclusions
● Dengue disease burden increasing globally
● Several dengue vaccines in development. Sanofi Pasteur CYD
vaccine the most advanced
● > 20 clinical trials completed or ongoing
● > 28,000 subjects received > 1 dose of CYD vaccine
● Favorable safety profile in children adolescents and adults
● Balanced neutralizing antibody response against 4 serotypes
● First efficacy trial in Thailand – Results available later in 2012 and
2 major efficacy trials (in Asia and Latin America) ongoing
| 33
Thank you!