hcv vaccine –where do we stand? - comtecgroup · habersetzer et al gastroenterology 2011. 5/15...
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HCV Vaccine – where do we stand?
U. Spengler
University of Bonn
THE IDEAL GOAL: The vaccine should induce sterilizing immunity
A MORE REALISTIC GOAL: Prevention of chronic persistent infection
Osburn Gastroenterology 2010
Feinstone et al. CID 2012
Osburn Gastroenterology 2010
Upon HCV re‐infection patients have reduced max HCV loads and reduced duration of acute disease
Re‐infection is associated with generation of cross‐reactive neutralizing Abs
Re‐infection is associated with the appearance of new multispecific T cell responses
AntigenAdjuvant
T
MHCII
Co‐stimulatory signals
CD4+ HelferT ‐
Helper Cells
CD8+ cytotoxic T ‐
Cells
B ‐
Cells
IFN‐
T
MHCI
Neutralising Abs
Correlates of Protective Immunity
Neutralising Antibodies:
Broad, multispecific T cell responses:
Neutralising antibodies appear much earlier in
resolving than persisten hepatitis C and
contemporaneous isolates are efficiently
neutralized.
Rare spontaneous elimination of chronic hepatitis
C may involve late neutralizing Ab responses. Rhaguraman et al. JID 2012
Pestka et al. PNAS 2007Dowd et al. Gastroenterology 2009
T cell responses are temporally associated with
control of primary and secondary HCV infection.
Depletion of CD4+ and CD8+ T cells in immune
chimpanzees results in prolonged or persistent
HCV infection.
Shoukry et al. J Exp Med 2003Grakoui et al. Science 2003
Rehermann J Clin Invest 2009
41/2/6
3
1/2/3
41
1/2
1/2/31/2/3
1/2 1/2/6
5
1/3
A preventive vaccine should be broadly reactive to many isolates
To prevent shifts in dominant genotype in some regions of the world
To also protect migrant populations
To prevent emerging of new more violent isolates
The Problem of Global HCV Diversity
C. Walker EASL Monothematic Conference on HCV 2012
Meta‐Analysis of 13 published Chimpanzee Studies
Recombinant envelope glycoproteins (E1/E2)
Virus‐like particles (C‐E1‐E2)
Recombinant DNA vaccines
Recombinant MVA and VV vectors
Dahari et al. Gastroenterology 2010
PooledResults:
Dahari et al. Gastroenterology 2010
Meta‐Analysis of 13 Chimpanzee Studies
E1/E2 antibody vaccineNovartis/Chiron
Recombinant genotype 1a (HCV1) E1 and E2
proteins
Generated in CHO cells
micro‐fluidised (MF59) oil in water emulsion
as adjuvant
Sterilizing Immunity and Resolution in Chimpanzees
The vaccine seems to also induce HCV‐specific CD4+ T cells which may protect from HCV persistence
M. Houghton Immunol Rev 2011
S.E. Frey et al.; Vaccine 2010; 28: 6367
Safety and Immunogenicity of HCV E1E2 Vaccine Adjuvanted with MF59 Administered to Healthy Adults
Characterization of Antibodies Induced by Vaccination with Hepatitis C Virus Envelope Glycoproteins
R. Ray et al.; J Infect Dis 2010; 202: 862
Stamataki J Infect Dis 2011
„T cell“
vaccineOkairos
Gene cassette encompassing non‐structural
proteins NS3‐NS5B
Derived from HCV genotype 1b strain Bk
Expressed from recombinant adenovirus
vectors, sometimes also plasmids and vaccinia
vectors
Peak viraemia 100‐fold reduced in vaccinated versus control animals.
Duration of disease shorter in vaccinated (1‐7 wks) versus control animals (16‐20 wks).
T cell HCV Vaccine in Chimpanzees
Folgori et al. Nat Medicine 2006
Anjmals received Ad6, Ad24 or plasmid DNA
vaccines and were challenged with a
genotype 1a isolate (H77)
E. Barnes Science Translational
Medicine 2012
The NS3‐NS5B gene cassette elicits strong T cell responses in humans when delivered with ChAd3 and Ad6 vectors
E. Barnes Science Translational Medicine 2012
Cross‐recognition of
genotypes 1a and 3a
Therapeutic Vaccines
Targeted to strengthen and recover exhausted T cell responses rather to induce neutralizing antibodies
TG4040 Phase I Study: Treatment‐naive PatientsDesign
TG4040 = modified poxvirus (Ankara strain) expressing HCV NS3, NS4 and NS5B
Habersetzer et al Gastroenterology 2011
Habersetzer et al Gastroenterology 2011
5/15 patients developed vaccine‐induced strong HCV‐specific cellular immune responses
8 patients had transient drops in HCV viraemia (from ‐0.52 log to ‐1.24 log)
The most pronounced drop in HCV RNA occurred in two patients who also showed the strongest T cell responses
All doses were well tolerated without serious adverse events
TG4040 Phase I Study: Treatment‐naive Patients
TG4040 Phase I Study: Treatment‐naive PatientsELISpot Results
Habersetzer et al Gastroenterology 2011
2 electric pulses (60 ms) immediately after DNA
injection
DNA‐Vakzination mit in vivo Elektroporation
M. Sällberg EASL 2009
M. Sällberg EASL 2009
167 µg → no effects on viral load ___
or ALT ‐‐‐‐‐
500 µg
1500 µg M. Sällberg EASL 2009
Intercell IC41 Peptid‐Vakzine
Poly‐Arginin
Klade et al. Gastroenterology 2008
Intercell IC41 Peptide‐Vaccine Phase II Study
Klade et al. Vaccine 2012
50 treatment‐naive patients HCV genotype I
Group A:
8 intradermal bi‐weekly injections plus Imiquimod (TLR‐8 Agonist)
Group B
: 16 subcutaneous injections every week; no imiquimod
0.2 log (p=0.001)
0.46 log(p< 0.001)In patients with high viral loads
(>2x106
IU/ml) 0.61 log, p=0,002
8 patients (24%) > 0.8 log drop in HCV loads
Wedemeyer et al. Vaccine 2009
35 patients ; 6 injections weeks 28 ‐
48
Therapeutic IC41 Vaccine as late add‐on to standard p‐interferon/ribavirin
Increased HCV‐specific T cell responses in 73%.
However, IC41 did not delay relapse,
which occurred in 8 patients (32%)
CoreNS3
Phase II Study in treatment‐naive (n= 110) and non‐responder (n=24) Patients
Randomisation 1 : 1 Standard therapy versus standard therapy + Tarmogen
5 GI 5005 weekly run‐in injections, then boostering every 2 months on Peg/R therapy
Triple arm: 68 treatment‐naive, 18 non‐responder patients
SOC arm: 5o treatment naive, 19 non‐responder patients
Tarmogen = recombinant HCV Core‐NS3 fusion proteinexpressed in Yeast
GlobeImmune Phase IIb Study GI 5005‐02
I.M. Jacobson et al. EASL 2010
63%
45%58%
48%
GlobeImmune GI 5005 Phase IIb Study
I.M. Jacobson et al. EASL 2010
Shiffman et al. AASLD 2012
33%
11%
17%
5%
*: p=0.037
GI5005 Triple
SOC
63%
27%
TH‐Naive Non‐Responder
IL28B‐GT TT
Conclusions
•
It is unlikely that a HCV vaccine can obtain sterilizing immunity. However, attenuated primary infection may still afford protection
from chronic hepatitis
•
Many promising vaccine candidates have entered clinical trials but show limited efficacy
•
Suitable high risk populations should be defined for broader studies on clinical utility.
Thank you for your attention