ALG-020572 and ALG-020576: Best-in-Class Potential

Add your logos here

Background and Aims

Methods

Wing Modification with Luxna 3rd Gen BNA Improved Potency and Reduced Liver Toxicity

References

Financial Disclosures

Reducing hepatitis B virus (HBV) S antigen (HBsAg) is key to

achieving functional cure in chronic hepatitis B (CHB)

patients. Antisense oligonucleotides (ASOs) are effective in

reducing HBsAg in animal models and CHB patients.

However, hepatotoxicity is a major side effect of ASO

administration that can be exacerbated with higher affinity

Locked-Nucleic Acid (LNA) modified ASOs. Next generation

Bridged Nucleic Acid (BNA) and nucleobase modified

monomers can reduce hepatotoxicity while maintaining

efficacy. We have therefore applied these chemistries in our

LNA-containing HBV targeting ASOs.

ASOs with LNA and BNA chemistries were synthesized on

ABI 394 and Expedite 8909 synthesizers using standard

phosphoramidite chemistry. In vitro screening of LNA ASOs

was carried out in HepG2.2.15 cells using a HBsAg release

assay. Potent LNA-containing ASOs were chosen for

conjugation with our proprietary N-Acetylgalactosamine-4

(GalNac4). BNA wing and nucleobase modifications were

applied using an in-house algorithm and we compared these

constructs to the all-LNA ASO parents in the adeno-

associated virus (AAV)-HBV mouse model.

1) Setoguchi K. et. al. Molecular Therapy: Nucleic Acids Vol. 9 December 2017

2) Kobori T. et. al. Poster 066 OTS 2019

All authors are Aligos Therapeutics employees

Jin Hong, Rajendra Pandey, Vivek K. Rajwanshi, Dinah Misner, Hua Tan, John Cortez, Yuchun Nie, Suping Ren, Dana Cho, Laxman Eltepu, Tilani De Costa,

Priya Mishra, Hyunsoon Kang, Aneerban Bhattacharya, Sushmita Chanda, David B. Smith, Julian A. Symons, Lawrence M. Blatt and Leonid N. Beigelman

Aligos Therapeutics, Inc., South San Francisco, CA, USA

B e s t i n c l a s s h e p a t i t i s B v i r u s a n t i - s e n s e o l i g o n u c l e o t i d e s :

N e x t g e n e r a t i o n b r i d g e d n u c l e i c a c i d c h e m i s t r i e s

s i g n i f i c a n t l y i m p r o v e t h e t h e r a p e u t i c i n d e x b y r e d u c i n g

h e p a t o t o x i c i t y a n d i n c r e a s i n g i n v i v o e f f i c a c y i n a m o u s e

m o d e l

Abstract SAT434

ConclusionsA) Applying Luxna chemistries, including 3rd generation BNA wing and

nucleobase gap modifications can increase therapeutic index as demonstrated

by in vivo studies in the AAV-HBV model.

B) ALG-020572 and ALG-020576 are HBV ASO development candidates

incorporating Luxna chemistries that target the HBV S and X regions

respectively. Both compounds demonstrated enhanced in vivo potency when

compared to the Ph2 clinical compound, GSK836.

C) Combination of ALG-020572 (S) and ALG-020576 (X) may have multiple

advantages. Results from in vitro and in vivo combination studies are pending.

Figure 5. Dose-Response of ALG-020572, ALG-020576 and GSK836 in the AAV-HBV MouseModel. All 3 oligonucleotides were dosed subcutaneously at two dose levels: 6x10mg/kgand 6x3mg/kg. All mice received 3 loading doses on Days 0, 3 and 7, then 3 maintenancedoses on Days 14, 21 and 35. Overall ALG-020572 targeting the S region and ALG-020576targeting the X region have similar in vivo potency. Both oligonucleotides demonstrateenhanced potency compared to GSK836.

A)

B)

Aligos ASO Platform Technology

GalNac4

Figure 1. ASO Platform. ASOs contain LNA as well as Luxna 3rd

generation BNA AmNA1 and Scp BNA2 in the wings. The gapregion contains Luxna nucleobases 8-Amino A, 8-Amino G, 5-OHC and 2-Thio-T. A novel GalNac4 is attached to the ASO througha unique linker structure

(5m)ScpC

GalNac4

ALG-020089, 3x10 mg/kg

ALG-020279, 3x10 mg/kg

Vehicle

C)ALG-020089, 3x10 mg/kg

ALG-020279, 3x10 mg/kg

Vehicle

ALG-020572 and ALG-020576 are Development Candidates Containing Luxna Chemistries

Figure 3. A single (2s)T substitution in theDNA Gap of ASO eliminated liver tox whilemaintaining potency. ALG-020090 is allLNA HBV ASO with all DNA Gap. A) ALG-020239 is identical to ALG-020090 exceptthat the 2nd position of the gap contains(2s)T instead of DNA T. B) In AAV-HBVmouse model, both oligos were dosedsubcutaneously 3x10mg/kg, weekly. Serialblood collections were made every 5 daysand HBsAg ELISA was carried out in theserum. With nucleobase modification, invivo potency was maintained. C) When ALTassay was conducted in the same serum,the nucleobase gap modification eliminatedliver tox with maximum ALT reduced 20times.

A)

B) C)

(2s)T

GalNac4

ALG-020090, 3x10 mg/kg

ALG-020239, 3x10 mg/kg

Vehicle

ALG-020090, 3x10 mg/kg

ALG-020239, 3x10 mg/kg

Vehicle

Gap Modification with Luxna Nucleobase Reduced Liver Toxicity While Maintaining Potency

ALG-020572

ALG-020576

Figure 4. Aligos HBV ASO DevelopmentCandidates with Potential forCombination. ALG-020572 and ALG-020576 target the S and X regions asshown. These can be developedindividually or in combination. Thecombination demonstrates broadergenotypic coverage, a higher resistancebarrier and is less likely to lose thecleavage site in integrated HBVgenomes.

Genotype A B C D E F G H I J

# of Clinical Isolates 1260 2306 3202 1367 376 318 134 45 103 30

ALG-020572 (S) 98% 100% 99% 100% 100% 100% 100% 100% 100% 100%

ALG-020576 (X) 99% 100% 99% 100% 96% 100% 99% 100% 100% 97%

ALG-020572 (S) + ALG-020576 (X) 100% 100% 100% 100% 100% 100% 100% 100% 100% 100%

Table 1. Aligos HBV ASO Development Candidates % Homology across HBVGenotypes Individually or in Combination. ALG-020572 (S) and ALG-020576(X) show a high degree of homology with >7,774 HBV clinical isolates acrossGenotypes A to J as individual triggers. When combined, the % homology is100% across all clinical isolates of all genotypes. Homology is defined asperfect match or with 1 mismatch.

Loading Doses Days 0, 3 and 7 followed by 3 Weekly Maintenance Doses

2.0

2.5

3.0

3.5

4.0

4.5

5.0

Serum HBsAgMean ± SEM

Day of study

HB

sA

g (

IU/m

L)

0 5 10 15

G 01: Vehicle, SC, 6 doses

G 03: ALG-020576, 6x10 mg/kg, SC

G 04: ALG-020576, 6x3 mg/kg, SC

G 05: ALG-020572, 6x10 mg/kg, SC

G 06: ALG-020572, 6X3 mg/kg, SC

G 15: GSK836, 6x10 mg/kg, SC

G 16: GSK836, 6x3 mg/kg, SC

20 25 30 35

ALT levels were normal for all dose groups

Figure 2. A single Scp BNA substitution inthe wing of all LNA ASOs increased in vivopotency and reduced liver toxicity. ALG-020089 is an all LNA HBV ASO. A) ALG-020279 is identical to ALG-020089 exceptthat the 2nd position in the 3’ wing contains(5m)Scp C instead of LNA C. B) In the AAV-HBV mouse model, both oligonucleotideswere dosed subcutaneously 3x10mg/kg,weekly. Serial blood collections were takenevery 5 days and HBsAg ELISA was used tomeasure serum levels. With 3rd Gen BNAchemistry, the HBsAg nadir was improved0.5 log10 (IU/ml). C) ALT measurement in thesame samples indicated that maximum ALTwas reduced 3-fold with 3rd Gen BNA.