NASDAQ: ABUS www.arbutusbio.com
Durable inhibition of hepatitis B virusreplication and antigenemia using subcutaneously administered siRNA agentAB-729 in preclinical models
Amy C.H. Lee
EASL International Liver Congress
12 April 2018 Paris, France
2
90MChina
15MEurope
2MUnited States
~900kpeople die every year as a consequence despite the availability of vaccines and antivirals.
257Mpeople are chronically infected with HBV, globally.
Source: Hepatitis B. WHO (2017) http://www.who.int/mediacentre/factsheets/fs204/en/
Key to Therapeutic Success in HBVREDUCE/SUPPRESS VIRAL
DNA & ANTIGENS
Viral Replication
Viral Proteins/HBsAg
cccDNA Formation /Function
RE-AWAKEN/BOOST IMMUNE RESPONSE
Reduced HBsAg
Immunotherapy
A combination approach to these key factors will drive cures
AB-729• Novel RNA interference agent
• Inhibits HBV replication, reduces all HBV transcripts, and lowers all HBV antigens
• Proprietary liver targeting technology
• Durable activity following a single subcutaneous dose
AB-729• Novel RNA interference agent
• Inhibits HBV replication, reduces all HBV transcripts, and lowers all HBV antigens
• Proprietary liver targeting technology
• Durable activity following a single subcutaneous dose
Polymerase, Core Ag, e Ag, pgRNA
sAg
sAg
HBx
siRNA delivery is mediated by a conjugated targeting ligand; GalNAc
AB-729 Mechanism of Action
• Cell uptake via GalNAc interaction with ASGPR
• Asialoglycoprotein Receptor– Helps clear desialylated proteins from serum
• High capacity uptake system– 0.5-1 million copies/cell– Rapid 15 min recycling time
• Advantageous tissue specificity– Highly expressed in hepatocytes– Conserved across species
Nucleus
RecyclingASGPR
RISC loading
Target Protein
X
GalNAc-siRNA
ASGPR
Clathrin-coated pit
mRNA cleavage
0 2 4 6 8 1 0-1
0
1
2
3
4
W e e k s A fte r A d m in is tr a t io n in A A V M ic e
Seru
m H
BsA
g
(Lo
g I
U/m
L)
S a lin e
A B -7 2 9 , 3 m g / k g S C
L L O Q
A R B -1 4 6 7 , 0 .3 m g / k g IV
AB-729 has longer duration of activity than ARB-1467, a Ph2 LNP siRNA agent
Adding New Value to Arbutus HBV Portfolio
1 dosesiRNA
Mean (n=5) ± SD
• This study utilized an early discovery-stage siRNA
• GalNAc delivery provides more durable siRNA activity than LNP – All LNP dose groups had resolved activity before end of study, whereas GalNAc activity persisted
0 1 2 3 4 5 6 7 81
2
3
4
G a lN A c v s L N P D e liv e r y
W e e k s a f te r A d m in is t r a t io n in A A V M ic eSe
rum
HB
sAg
(Lo
g IU
/mL)
S a lin e
0 .0 3 m g / k g L N P -e n c a p s u la t e d IV
0 .1 m g / k g L N P -e n c a p s u la te d IV
0 .3 m g / k g L N P -e n c a p s u la te d IV
1 m g / k g L N P -e n c a p s u la te d IV
1 m g / k g G a lN A c -c o n ju g a te d S C
GalNAc-Conjugates Have More Durable siRNA Activity
1 dosesiRNA
Pooled (n=5) samples
- 1 0 1 2 3
0
2 0
4 0
6 0
8 0
1 0 0
G e n o t y p e B
G e n o t y p e C
G e n o t y p e D
G e n o t y p e A
C o n c e n t r a t i o n ( l o g n M )
% I
nh
ibit
ion
of
HB
sA
g
- 1 0 1 2 3
0
2 0
4 0
6 0
8 0
1 0 0
L A M , T L V r e s i s t a n t
A D V r e s i s t a n t
W i l d t y p e G t D
E T V , L A M , T L V r e s i s t a n t
C o n c e n t r a t i o n ( l o g n M )
AB-729 has Pan-Genotypic ActivityThe siRNA functions well against all tested genotype & Nuc-resistant variants • Targeted HBV genome site is highly conserved across gt A-H
Mean (n=2) ± SD
HBV Variant HBsAg EC50(nM)
Genotype A 11
Genotype B 40
Genotype C 59
Genotype D 62
ETVr L528M/M552V/T532G/S550I 61
TLVr M552V+L528M 89
ADVr A529V 143
Wildtype 73
- 2 - 1 0 1 2 3
- 2 0
0
2 0
4 0
6 0
8 0
1 0 0
T o t a l H B V R N A
C o n c e n t r a t i o n ( L o g 1 0 n M )
To
ta
l H
BV
RN
A*
% i
nh
ibit
ion
A B - 7 2 9
U n c o n j u g a t e d s i R N A o f ' 7 2 9
- 2 - 1 0 1 2 3
- 2 0
0
2 0
4 0
6 0
8 0
1 0 0
S e c r e t e d H B s A g
C o n c e n t r a t i o n ( L o g 1 0 n M )
Se
cr
et
ed
HB
sA
g*
% i
nh
ibit
ion
AB-729 In Vitro Potency
• Effect of ligand-mediated delivery shown with ~2 log right shift versus unconjugated control
• No cytotoxicity detected up to highest AB-729 dose tested
Pleiotropic Effects on HBV Demonstrated in AAV-HBV Mouse Primary Hepatocytes
Mean (n=3) ± SD* Normalized to GAPDH mRNA
AB-729 EC50(nM)
HBsAg (secreted) 16.9
HBeAg (secreted) 10.1
3.5 kb HBV RNA 3.2
Total HBV RNA 4.9
Cytotoxicity > 19,591
CC50/EC50 for sAg > 1,158
• Concentration dependent asialofetuin (ASF) suppression of GalNAc-siRNA effect on multiple HBV markers* verifies drug activity is occurring through ASGPR interaction
• Novel GalNAc ligand conjugates provide excellent avidity for receptor binding
0 1 0 0 2 0 0 3 0 0 4 0 0 5 0 00
5 0 0
1 0 0 0
1 5 0 0
[L ig a n d lin k e d to F lu o ro p h o re ] (n M )
∆ M
ea
n F
luo
resc
en
ce I
nte
nsi
ty ABUS LigandFor ‘729
ABUS Ligand 2
External Ligand
-3 -2 -1 00
2 0
4 0
6 0
8 0
1 0 0
A S F C a n C o m p e t e O u t '7 2 9 A c t iv it yin P r im a r y A A V M o u s e H e p a to c y te s
A S F (L o g 1 0 µ M )
To
tal H
BV
RN
A/G
AP
DH
% in
hib
itio
nConfirmation of Mechanism of Action Asialoglycoprotein Receptor Interaction Demonstrated In Vitro
* sAg, eAg data similar; not shown
Dotted line = ‘729 activity at 0.3 ug/mL in absence of
competitor
Mean (n=3) ± SD
• Clear dose response, achieved max effect detectable in this model
• Supports clinical dosing frequency of 1 month (or more)
0 2 4 6 8 1 0
- 1
0
1
2
3
4
W e e k s A f t e r O n e S C D o s e
Se
ru
m H
Bs
Ag
(Lo
g I
U/
mL
) 1 m g / k g
3 m g / k g
9 m g / k g
L L O Q
S a l i n e
1 d
(right panel, & next slide)
AB-729 In Vivo Single Dose Response & DurationIn AAV Mouse
Liver sections stained for HBsAg
3 mg/kg
9 mg/kg
Saline
Control siRNA 9 mg/kg
‘729 TreatmentControls1 mg/kg
Mean (n=5) ± SD
200 µm
-1
0
1
2
3
4
5
In h ib it io n o f M u lt ip le H B V M a r k e r s b y '7 2 9
LOG
10
In
hib
itio
n#
C o n tro l s iR N A 9 m g / k g
'7 2 9 1 m g / k g
'7 2 9 3 m g / k g
'7 2 9 9 m g / k g
*
**
*
L iv e r 3 .5 k b
H B V R N A
S e ru m
H B V D N A
S e ru m
H B e A g
L iv e r T o ta l
H B V R N A
S e r u m
H B s A g
L iv e r
H B s A g
Pleiotropic Effects of AB-729 on HBV In VivoEffects are consistent with RNAi mechanism of action
• Dose responsive effects on all measured HBV markers
• cccDNA not significantly present in this model; not expected to be directly impacted by RNAi
14 days after single dose treatment in AAV mice (mean of n=5 ± SD) # relative to baseline (serum readouts) or saline control (liver readouts)* indicates signal for ≥1 animal below LLOQ
AB-729• Novel RNA interference agent
• Inhibits HBV replication, reduces all HBV transcripts, and lowers all HBV antigens
• Proprietary GalNAc-conjugate liver targeting technology
• Pan-genotypic activity
• Multi-month duration of surface antigen inhibition after a single SC dose – Significantly improved over ARB-1467, a Phase 2 IV LNP siRNA agent
• Next: Initiate GLP safety studies
Polymerase, Core Ag, e Ag, pgRNA
sAg
sAg
HBx
Acknowledgments – Arbutus Team:Emily ThiXin YeNicholas SneadChris PasetkaHui HuangAndrew KondratowiczJanet PhelpsOwen DalyLuying PeiAngela HussainkhelJoanna PanKaylyn KwokLily ZhangAmy C.H. Lee
Mark WoodAlan MartinLorne PalmerRichard HollandKieu LamAdam JudgeJames Heyes
Holly SteuerAndrzej ArdzinskiLucy WangKim SteverLauren BaileyAndy Cuconati
Sean SempleMerete EisenhardtDunmin MaoRobbin BurnsSunny TangEllen EvangelistaTroy Harasym
Agnes JaroszSara MajeskiCory Abbott Kevin McClintock
Michael J. Sofia