HSV-2 - Redbiotec

HSV-2 therapeutic

vaccine program

Subunit vaccine candidates

Our HSV-2 vaccine program

• Therapeutic subunit vaccine

• T-cell-based

• Aim: Best-in-class antigens by engineering

• Excellent standing (Sept 2017): Redbiotec preclinical

vaccine leads show > 90% reduction of lesion score

(vs. approx. 50% for GEN-003 of Genocea)

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PRIVILEGED & CONFIDENTIAL

HSV-2: Opportunity for a new vaccine

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• Seroprevalence HSV-2, 15-49 y/o: 16 % (U.S.)

• New genital herpes cases / year (U.S.): 300’000

• High number of symptomatic patients: 10-25%

• Standard treatment: antivirals

• Economic burden (U.S.): > 1 bn USD/year

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• Deals closed with pharma companies in U.S., Asia and Europe • Trade sale of spin-off Redvax to Pfizer for its CMV vaccine program • Internationally recognized scientists as scientific advisors

• Engineering and production of >100 novel proteins and protein

complexes • First company having successfully developed stable CMV pentamer

at >95% purity

Track record of Redbiotec in novel proteins

HSV-2 therapeutic

vaccine program

Preclinical data

Redbiotec’s HSV-2 preclinical program


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Our goals: To develop a potent T-cell-based therapeutic vaccine

against HSV-2, that:

- reduces frequency of genital lesion recurrences, and/or

- reduces symptoms & time to lesion healing, and/or

- decreases duration of shedding and eventually

prevents transmission

Our tools: • Immunogenicity prediction tools

• Human PBMC database of HSV-2/-1, HSV-2 and

HSV-1 samples

• The guinea pig model of genital infection

• Set of new immunological assays /reagents

Our products:

Recombinantly produced HSV-2 antigens (RBT-x) (22 different purified antigens)

Primary infection: epithelial cells

Primary herpetic disease: genital tract

Nearby nerve endings

Retrograde transport

Anterograde transport

Latency in sensory ganglia

Reactivation and re-infection

Back to latency Recurrent herpetic disease: genital tract

Our target sites:

RBT

RBT

Overview of Redbiotec’s HSV-2 preclinical stages


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antigen selection process

in silico immunogenicity

in vitro immunogenicity

in vivo immunogenicity & protection

in vivo protection & MOA

• data mining searches • 35 antigenic sequences selected

• web-based prediction tools • different prediction methods • 22 recombinant antigens generated

lead candidate(s)

• screens with human PBMC samples • cytokine profile assays • 12 antigens further selected

• animal studies in guinea pigs (phase 1+2) • disease markers • immunogenicity markers • 4 antigens further selected

• final selection: 1-2 antigens • evaluation of pharma partners

• antigen combinations tested in animals (phase 3) • specific antigens to be further selected

Q3-Q4 2017 Q1-Q4 2016 Q4 2016 – Q2 2017 Q4 2017

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in vivo STUDIES with the guinea pig model

In vivo study design: therapeutic protective efficacy of RBT antigens against recurrent infection and disease

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Schematic view of the guinea pig study. Twelve recombinant antigens were tested for protection against recurrent

genital herpes in 2 different studies using 5-6 animals per vaccination group in each study.

HSV-2 infection Immunization with

adjuvanted RBT antigens Boost

End of Study

• Daily lesion scoring (from D27): frequency

and severity

• Viral shedding determination

• CD4+ / CD8+ T-cells: frequency and function Guinea pig

groups 1-14

15 25 85 0

Days

ACUTE

INFECTION LATENCY

Acute vaginal infection following intravaginal inoculation of HSV-2 (virus titers shed & severity (clinical score 0-4))

RBT-3 12 29 2.4 88.5% 29 2.4 93.8%

RBT-5 12 63 5.3 75.0% 74 6.2 84.2%

RBT-11 12 68 5.7 73.0% 88 7.3 81.3%

RBT-12 12 85 7.1 66.2% 93 7.8 80.2%

RBT-14 12 65 5.4 74.2% 69 5.8 85.3%

RBT-23 12 72 6.0 71.4% 103 8.6 78.1%

RBT-24 12 87 7.3 65.4% 91 7.6 80.6%

RBT-26 12 45 3.8 82.1% 45 3.8 90.4%

RBT-6 6 40 6.7 72.6% 8 8.2 83.4%

RBT-15 6 43 7.2 70.6% 44 7.3 85.1%

RBT-21 6 37 6.2 74.7% 88 14.7 70.3%

RBT-25a 6 45 7.5 69.2% 47 7.8 84.1%

RBT-25b 6 41 6.8 61.2% 41 6.8 76.5%

HSV-2 dl5-29 12 15 1.3 94.0% 15 1.3 96.8%

Adjuvant alone 10 210 21.0 0.0% 392 39.1 0.0%

Therapeutic

efficacy

Therapeutic

efficacy

Frequency of recurrencies Severity of disease

Antigen for

immunization

No. of

animals

Days with

recurrencies (D27 to 85)

Positive days

per animal (D27 to 85)

Disease

severity (D27 to 85)

Mean score

per animal

(by D85)

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Summary of the performance of RBT antigens in the guinea pig model of genital HSV-2 infection

* scores were done every day between Day 27 and 85 (85 days p.i.)

+ data points of antigens that were tested in both phases (using 10 or 12 animals in total) were pooled to calculate the therapeutic efficacy

° RBT-23 corresponds to Redbiotec’s gD, RBT-25a and b correspond to different formulation of the same antigen

* * + °

Results were obtained with either 12, 10 or 6 animals per vaccination group. Shown are a) the mean of the days with recurrent events in

each group and b) the mean of the severity of the events in each group, within Day 27 and Day 85 (p.i.).

RBT-3 and RBT-26 strongly reduce the number of herpetic recurrent events

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Days with recurrencies Severity of disease

Results represent groups of the phase 2 study with either 6 or 5 animals per vaccination group. Shown are cumulatively a) the mean of

the days with recurrent events in each group and b) the mean of the severity of the events in each group, from Day 27 to Day 85 (p.i.).

RBT-3 very efficiently protects against virus shedding in the vaginal mucosa

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Guinea pig vaginal secretions were evaluated by qPCR every 5 days, from Day 35 to Day 55 post infection, for HSV-2 DNA shedding.

Samples with <150 copies/mL by 40 cycles were reported as negative. Shown is the average value of 5-6 animals. Data points derive

from Phase 2 samples. RBT-23 corresponds to Redbiotec’s gD.

Virus shedding – average values

HS

V-2

sh

ed

din

g (

DN

A c

op

y n

um

be

rs

)

RB

T-3

RB

T-5

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T-1

1

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T-1

2

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T-1

4

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T-2

3

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T-2

4

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T-2

5

RB

T-2

6

dl5

-29

Ad

j. a

lon

e

0

5 0 0

1 0 0 0

1 5 0 0

2 0 0 0

2 5 0 0

D a y 3 5

D a y 4 0

D a y 4 5

D a y 5 0

D a y 5 5

HS

V-2

sh

ed

din

g (

DN

A c

op

y n

um

be

rs

)

RB

T-3

RB

T-5

RB

T-1

1

RB

T-1

2

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T-1

4

RB

T-2

3

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T-2

4

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T-2

5

RB

T-2

6

dl5

-29

Ad

j. a

lon

e

0

5 0 0

1 0 0 0

1 5 0 0

2 0 0 0

2 5 0 0

D a y 3 5

D a y 4 0

D a y 4 5

D a y 5 0

D a y 5 5

HS

V-2

sh

ed

din

g (

DN

A c

op

y N

o.)

RB

T-3

RB

T-5

RB

T-1

1

RB

T-1

2

RB

T-1

4

RB

T-2

3

RB

T-2

4

RB

T-2

5

RB

T-2

6

dl5

-29

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

D a y 3 5

D a y 4 0

D a y 4 5

D a y 5 0

D a y 5 5

RBT-3 very efficiently protects against virus shedding in the vaginal mucosa

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Guinea pig vaginal secretions were evaluated by qPCR every 5 days, from Day 35 to Day 55 post infection, for HSV-2 DNA shedding.

Samples with <150 copies/mL by 40 cycles were reported as negative. Shown is examples of Days 45 and 55. Data points derive from

Phase 2 samples. RBT-23 corresponds to Redbiotec’s gD.

Virus shedding – distribution of single values

Day 35

D a y 4 5

HS

V-2

sh

ed

din

g (

DN

A c

op

y N

o.)

RB

T-3

RB

T-5

RB

T-1

1

RB

T-1

2

RB

T-1

4

RB

T-2

3

RB

T-2

4

RB

T-2

5

RB

T-2

6

dl5

-29

Ad

j. a

lon

e

0

2 0 0

4 0 0

6 0 0

8 0 0

2 0 0 0

6 0 0 0

1 0 0 0 0

D a y 5 0

HS

V-2

sh

ed

din

g (

DN

A c

op

y N

o.)

RB

T-3

RB

T-5

RB

T-1

1

RB

T-1

2

RB

T-1

4

RB

T-2

3

RB

T-2

4

RB

T-2

5

RB

T-2

6

HS

V-2

Dl5

-29

Adj. a

lone

0

2 0 0

4 0 0

6 0 0

8 0 0

1 0 0 0

1 2 0 0

1 4 0 0

5 0 0 0

6 0 0 0

D a y 5 5

HS

V-2

sh

ed

din

g (

DN

A c

op

y N

o.)

RB

T-3

RB

T-5

RB

T-1

1

RB

T-1

2

RB

T-1

4

RB

T-2

3

RB

T-2

4

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T-2

5

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T-2

6

dl5

-29

Ad

j. a

lon

e

0

5 0 0

1 0 0 0

1 5 0 0

2 0 0 0

D a y 3 5

HS

V-2

sh

ed

din

g (

DN

A c

op

y N

o.)

RB

T-3

RB

T-5

RB

T-1

1

RB

T-1

2

RB

T-1

4

RB

T-2

3

RB

T-2

4

RB

T-2

5

RB

T-2

6

HS

V-2

dl5

-29

Adj. a

lone

0

5 0 0

1 0 0 0

1 5 0 0

2 0 0 0

6 0 0 0

7 0 0 0

HSV

-2 s

he

dd

ing

(DN

A c

op

y N

o.)

H

SV-2

sh

ed

din

g (D

NA

co

py

No

.)

Day 45

Day 50 Day 55

HSV

-2 s

he

dd

ing

(DN

A c

op

y N

o.)

H

SV-2

sh

ed

din

g (D

NA

co

py

No

.)

RBT antigens show immunogenicity upon re-stimulation of HSV-2-infected cells

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The IFN-γ secretion by splenocytes from HSV-2-infected guinea pigs after re-stimulation with 12 recombinant antigens was measured

by ELISPOT. Representative images are shown. RBT-23 corresponds to Redbiotec’s gD.

RBT-3 neg. ctrl

RBT-23 PHA pos. ctrl

RB

T-3

RB

T-5

RB

T-6

RB

T-1

1

RB

T-1

2

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T-1

4

RB

T-1

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RB

T-2

1

RB

T-2

3

RB

T-2

4

RB

T-2

5

RB

T-2

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PH

A

neg

. ctr

l

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

8 0 0

9 0 0

1 0 0 0

IFN

- s

ec

re

tin

g c

ell

s f

ro

m s

ple

no

cy

tes

(S

FU

)

Increased CD4+/CD8+ responses are detected in RBT-immunized guinea pigs

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T-cells positive for various markers were detected in spleen samples from immunized animals using flow cytometry. Both % and absolute

numbers were obtained. The bar graphs show absolute cell numbers. Statistical analysis was done with two-tailed unpaired t-test.

Asterisks represent P<0.05 compared to the negative control (Adjuvant alone). Positive control is the dl5-29 virus control. RBT-23

corresponds to Redbiotec’s gD. An example of the flow cytometry charts with % of CD4+/CD8+ populations is shown.

CD8+/NKT activation marker

Exhaustion marker

CD8+ frequency CD4+ frequency

25 Pos Cont Neg Cont

Functional T- and B-cells are identified in RBT-immunized guinea pigs

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Lymphocytes positive for various markers were detected in spleen samples from immunized animals with selected antigens (three

and the two study controls) using flow cytometry. Both % and absolute numbers were obtained. A representation of the strength of

the response is shown in form of a heat map based on absolute cell numbers. RBT-23 corresponds to Redbiotec’s gD.

highest response

lowest response

CD8+ frequency

CD4+ frequency

CD69 on

CD8+

CD69 on

CD4+CRTAM MHC II

B220 on

B-cellsIgM PD-1 2B4

RBT-3

RBT-23

RBT-25

dl5-29

Adj. alone

Activation

markers

Exhaustion

markers

Summary of immunological responses

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in vitro IMMUNOGENICITY assays with human samples

RBT antigens show immunogenicity in stimulated HSV-2 patient-derived PBMC

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HSV-1/-2-double infected donors

HSV-2-only infected donors

The IFN-γ response of donor PBMC was determined by ELISPOT (13 HSV-2-infected individuals (HSV-2-only and HSV-1/-2-double

infected) and 16 antigens analyzed). Each dot represents one positive donor. In blue the HSV-2-only-infected individuals are

depicted. Assay signal background is subtracted. Mean values are shown.

RB

T-3

RB

T-5

RB

T-6

RB

T-7

RB

T-1

1

RB

T-1

2

RB

T-1

3

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4

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T-1

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0

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T-2

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2

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3

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T-2

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T-2

6

0

2 0

4 0

6 0

8 0

1 0 0

1 2 0

1 4 0

1 6 0

SF

U /

2x

10

5 P

BM

C

PBMC from HSV-1-positive donors respond with low levels of IFN-γ upon HSV-2 antigen stimulation

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The IFN-γ response of donor PBMCs was determined by ELISPOT (11 HSV-1-infected individuals or 8 HSV-negative individuals, and 16

antigens analyzed). Each black dot represents one control donor. Assay signal background is subtracted. Mean values are shown.

SF

U /

2x

10

5 P

BM

C

RB

T-3

RB

T-5

RB

T-6

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T-7

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T-1

1

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2

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3

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4

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T-2

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T-2

1

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3

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T-2

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T-2

5

RB

T-2

6

0

2 0

4 0

6 0

8 0

1 0 0

1 2 0

1 4 0

1 6 0

HSV-1-only-infected donors

control donors

RBT antigens elicit IFN-γ responses in both CD4+ and CD8+ T-cells

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Mature Mo-DCs from HSV-2-positive samples were pulsed with RBT antigens and co-cultured with donor-derived CD4+ or CD8+

T-cells. The IFN-γ response was measured by ELISPOT.

CD4 T-cell

CD8 T-cell mature Mo-DC antigen

+ co-culture

with or IFN-γ

strong response

medium to low response

no response

* Donors: HSV-2-only or HSV-1/-2 double-infected

RBT-3 RBT-5 RBT-14 RBT-23 RBT-25 RBT-26

Donor 4

Donor 23

Donor 55

Donor 75

Donor 101

Donor 125 n.d.

Donor 51

CD4 responses

CD8 responses

HSV-2 therapeutic vaccine program at Redbiotec: achievements as of Q3 2017

• Twenty two different HSV-2 recombinant antigens (RBT-x) were successfully expressed and purified

• In vivo guinea pig studies revealed high therapeutic protective efficacy of single antigens:

- 88% and 93% efficacy of RBT-3 in reducing frequency and severity of recurrencies, respectively

- virus shedding in vaginal secretions upon RBT-3 immunization below the detection limit

- single antigens stimulating T-cell immune responses

• In vitro assays with human PBMC also revealed the immunogenicity of the RBT HSV-2 antigens

• Potential to increase antigen performance by:

- optimization of epitope content

- evaluation of adjuvant systems

- combination of antigens

• Three patents on “Means and Methods for Treating HSV“ were filed in March 2016

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Current collaboration partners

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UC Irvine, School of Medicine

Instituto de Biologia Experimental e Tecnológica

Zurich University of Applied Sciences

Blood Donation Center, Zurich


Swiss Federal Institute of Technology

Thank you

Redbiotec AG Wagistrasse 23

8952 Schlieren, Switzerland +41 44 738 20 00 (phone)

+41 44 738 20 01 (fax)

Dr. Lilli Stergiou

[email protected] www.redbiotec.ch

mailto:[email protected]

http://www.redbiotec.ch/

HSV-2 - Redbiotec

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