Gorilla Adenovirus Vectors for
Molecular Therapeutics and Vaccines
ASGCT 18th Annual Meeting May 13 , 2015
Adenovectors and Packaging Cell Lines
GenVec Technology
• Adenovectors with superior performance characteristics for therapeutics and vaccines
• Broad spectrum of applications for the platform
• Significant vector construction and manufacturing expertise
• Additional viral gene deletions enhance safety and provide large packaging capacity
• Proprietary cell lines supported by FDA master file
1
Human and Nonhuman Types
GenVec Adenovectors
• Multiple adenovirus vector types
Human
Monkey
Chimpanzee
Gorilla
• Gorilla adenovirus (GC44, GC45, GC46)
New adenovirus serotypes isolated from wild gorilla
Similar to species C human adenovirus
Grow productively in our cells lines
Very low seroprevalence in human populations
2
Human Seroprevalence
Gorilla Adenovectors
• Analyzed gorilla adenovirus vectors for prevalence in human populations
US
Sub-Saharan Africa
Benchmarked against Ad5, SAV7, Ad35
• Seropositives in the human population were infrequent
• The few positive titers were found to be very low
Too low to be inhibitory (IC90=200)
3
The U.S. Population Does Not Have High Levels of GC46-specific Neutralizing Antibodies
Approximately 240 serum samples were tested for neutralization of GC46
Frequency Titer distribution
IC90 titer
> 200 16-200 ≤ 16
GC46 SAV7 Ad5
100
1000
Tite
r (I
C-9
0)
200
Seropositives were infrequent, with titers too low to be inhibitory (IC90 = 200)
GC46 5.5%
94.5%
Ad5
42.5%
36.1% 21.4%
57.3%
41.3%
1.3%
SAV7
4
Distinct Advantages for Molecular Vaccines
Gorilla Adenovirus Vectors
Promising results in several vaccine preclinical models
• High-level, durable antibody responses from single administration
• High-level, durable T cell responses from single administration
• Repeat administration boosts responses
5
RSV Data Summary
• Protective – upper and lower respiratory tracts
• Durable – at least six months of protection
• Rapid – protection within two weeks
• Safe – no vaccine enhanced disease
• Breadth – immunological coverage of RSV diversity
6
Comparative Immunogenicity: Neutralizing Activity and Protection
4 Weeks
Serum for
neutralizing
antibody titer
RSV, 106 PFU, i.n. Buffer (FFB) rAd5F.0, 107 or 109 pu SAV7F.0, 107 or 109 pu GC46F.0, 107 or 109 pu
F Antigen IM
0
Lung RSV
5 days
post-
challenge
BALB/c H-2d
d
7
Comparative Immunogenicity
101
102
103
104
105
106
107
RSV
SAV7.F0 GC46.F0
109
107
PF
U/g
ram
lung
FFB 109
107 10
910
7
Ad5.F0
104
103
102
101
106
105
107
107 109
GC46.F0 107 109
SAV7.F0 107 109
Ad5.F0
64
128
256
512
PR
NT
(IC
-50)
Protection against RSV Serum neutralizing activity
• GC44.F0 and GC46.F0 induced titers comparable to an immunization with 1 x 106 PFU of RSV
• Can differentiate performance based on low dose immunizations
* = significantly less than RSV-primed mice
Single Administration
8
Time Course of Pulmonary RSV Replication in Immunized Mice
1 2 3 4 510
1
102
103
104
105
106
107
RS
V titers
(P
FU
/ g
lung)
Day post-challenge
FFB
RSV
GC46.F0
* = significantly different than FFB-primed mice
Mice, Balb/c
Challenge at 4 weeks post-immunization
GC46.F0 108 pu
RSV challenge 5 x 106 PFU
9
Characterization of GC46 Immunogenicity in the Cotton Rat Model
8 Weeks
Serum
RSV Long, 105 PFU, i.n. Buffer (FFB)
FI-RSV (Lot 100) 1:125 GC46F.0, 106 or 109
Lung RSV Nose RSV Histopathology
5 Days
post-
challenge
0 4
FI-RSV (Lot 100) 1:125
Serum
10
4
5
6
7
8
9
10
RSV FFB FI-RSVGC46 F 1e6 puGC46 F 1e9 pu
Ge
oM
ea
n L
og
2 T
ite
rs (
IC-6
0)
Day0 Day 28 Day 56
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
RSV FFB FI-RSVGC46 F 1e6 puGC46 F 1e9 pu
Ge
oM
ea
n L
og
10
Tite
rs (
pfu
/g)
Lung
Nasal
109 106
GC46.F0
(pu)
GC46.F0 Immunogenicity in the Cotton Rat Model
Serum neutralizing antibody Protection against RSV
• Lung and nasal titers were reduced to undetectable
• Nasal RSV titers were reduced 10-fold with GC46.F0 106 pu immunization
RSV FFB FI-RSV RSV FFB 106 109
GC46.F0
(pu)
Lung
LOD
Nasal
LOD FI-RSV
11
Durable Neutralizing Antibody Titers Induced by GC46.F0
16
32
64
128
256
512
1024
0 2 4 6 8 10 12 14 16 18 20 22 24 26
PR
NT
titer
(IC
50
)
Weeks post-immunization
GC46.F0 109 pu
GC46.F0 107 pu
FI-RSV
12
Upper and Lower Respiratory Tract Protection At Six Months
Lung
0
50
100
150
200
250
300
350
400
RSV A2 FI-RSV GC46.F0 e7GC46.F0 e9
Titer
(PF
U /
gra
m lung)
RSV 107 109
GC46.F0 FI-RSV
RSV A2 e6 FI-RSV 1:100 GC46.F0 e7 GC46.F0 e9100
1,000
10,000
100,000
RS
V t
iter
(PF
U /
nose)
Nasal
RSV 107 109
GC46.F0 FI-RSV
13
Malaria Data Summary
• Robust antigen specific T cell responses
• Robust antigen specific antibody responses
• Protection against P. yoelli challenge
14
%
C
SP
+ I
FNg+
CD
8+ T
-Cells
0
2
4
6
8
10
12
AdNull Ad5 GC44 GC45 GC46
Single administration of GC vector expressing PyCSP induces robust antigen specific T cell responses in mice
p
0
2
4
6
8
10
12 Media HA332-340
PyCSP280-288
PyCSP57-70
AdN
ull
GC
46
Ad5
Naiv
e
1 x 107 1 x 109
1 x 108
P< 0.001
P< 0.001
AdN
ull
GC
46
Ad5
AdN
ull
GC
46
Ad5
%
C
SP
+ I
FNg+
CD
8+ T
-Cells
Comparative Immunogenicity Antigen Specific T Cell Dose Response
Single administration of GC vector expressing PyCSP induces robust antigen
specific T cell responses in mice
16
P<
0.5
Ad
Nu
ll
GC
46
Ad5
Na
ive
1 x 107 1 x 109
1 x 108
AdN
ull
GC
46
Ad5
AdN
ull
GC
46
Ad5
Comparative Immunogenicity Antigen Specific Antibody Dose Response
Single administration of GC vector expressing PyCSP induces robust
antigen specific antibody responses in mice
17
0
10
20
30
40
50
60
DNA Ad5
DNA GC44
DNA GC45
DNA GC46
DNA null GC46 null
Naïve
% P
rote
ctio
n
36% 43%
14%
50%
0% 0%
Prime Boost
Comparative Immunogenicity P. yoelii Protection Against Challenge
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HSV Data Summary
• Rapid, durable reduction in clinical symptoms HSV2 challenge in ovariectomized female mouse
HSV2 recurrence model in female guinea pigs
• Rapid viral load reduction HSV2 challenge in ovariectomized female mouse
• Robust, durable T cell response
• Repeat administration boosts T cell response
19
Schematic of HSV2 Challenge Model Using Ovariectomized Mice
Single I.M. Injection
20
Reduced Clinical Symptoms
No treatment Blend of GV46.UL19 and GC46.UL47, 1e9 pu each
21
Reduced Viral Load
qPCR assay Plaque assay
p< 0.01 p< 0.05
No treatment Blend of GV46.UL19 and GC47, 1e9 pu each
22
n=18/Group
0
50
100
150
200
Perc
ent
of
Naï
ve V
iral
Tit
er
Naïve UL19 UL19 + UL47
Viral Load is Reduced (Plaque)
n=6/Group
Robust T Cell Response and Viral Load Reduction
T- Cell Response is Enhanced
Day 0 Day 14
Single I.M. Injection Splenocyte Harvest
Day 0 Day 21
Vaginal Swab(Day +7) Single I.M. Injection
Day 14
HSV2 Infection
0
2
4
6
8
10
12
14
16
18
20
Naïve UL19 UL19+ UL47
Perc
ent
CD
8+
IFNg
+ T
Cel
ls
23
Ad Prime
Ad Boost -
GC45
1E9
-
GC45
1E7 FFB
FFB
GC45
1E7
GC45
1E7
-
GC45
1E9
GC45
1E9
GC45
1E9
Ad Prime
Ad Boost -
GC45
1E9
-
GC45
1E7 FFB
FFB
GC45
1E7
GC45
1E7
-
GC45
1E9
GC45
1E9
GC45
1E9
4 week
prime/boost
interval
12 week
prime/boost
interval
** *** **** A) B)
Repeat Administration
Repeat immunization with gorilla adenovirus vectors boosts antigen specific T cell responses
24
Schematic of HSV2 Recurrence Model Using Female Guinea Pigs
25
Rapid, Durable Reduction of Clinical Symptoms for at Least 63 Days
Incidence
p
p
• Adenovectors with superior performance characteristics for therapeutics and vaccines
• Broad spectrum of applications for the platform
• Grow to high titer on our cells lines
• Support additional viral gene deletions for enhanced safety and large packaging capacity
• Promising results in several vaccine preclinical models High-level, durable antibody responses from single administration
High-level, durable T cell responses from single administration
Repeat administration boosts responses
Gorilla Adenovectors
28
Acknowledgments
Mike Cranfield
Keith Limbach
Noelle Patterson
Maureen Stefaniak
Eileen Villasante
Tom Richie
Duncan McVey
Jason Gall
Teresa Johnson
Lisa Wei
Joe Bruder
Chris Lazarski
Ping Chen
Damodar Ettyreddy
Barney Graham
Holly Torano
Hubert Kuete
Andrew Glenn
David Rangel
Grace Lee
Randy Osborn
Johanna Harvel
29