AB-423 is an inhibitor of HBV capsid assembly. AB-423 shows inhibitory effect on rcDNA production in AML12-HBV10 and HepDE19 cells with EC50s of ∼0.260 μM. AB-423 also suppresses cccDNA formation-dependent HBeAg production in the HepBHAe82 assay with an EC50 of 0.267 μM and inhibits HBV DNA levels in culture supernatants of HepG 2.2.15 cells with an EC50 of 0.134 μM. However, AB-423 has no cytotoxicity in any of the three cell lines.
AB-423 (30 and 100 mg/kg, p.o. bid) blocks HBV replication in a mouse model of HBV. AB-423 (100 mg/kg, p.o. bid) with entecavir (ETV, 100 ng/mg, qd, p.o.) or 0.1 mg/kg dose of ARB-1467 potently inhibits serum HBV DNA in an HDI model of HBV in immunodeficient NOD-SCID mice.
To test the compound combinations, HepBHAe82 (50,000 cells/well)
are plated in 96-well tissue-culture treated microtiter plates in
DMEM/F12 medium supplemented with 10% fetal bovine serum, 1%
penicillin-streptomycin and tetracycline (1 μg/mL), and incubated in a
humidified incubator at 37°C and 5% CO2 overnight. On the
next day, the cells are switched to fresh medium and treated with
inhibitor A and inhibitor B, at concentration range in the vicinity of
their respective EC50 values. The inhibitors are either diluted in 100% DMSO (ETV, TDF and AB-423) or growth medium (ARB-1467 and ARB-1740) and the final DMSO concentration in the assay is ≤0.5%.
The two inhibitors are tested both singly as well as in combinations
determine their effects on inhibition of rcDNA production. The final
DMSO concentration in the assay is 0.5%. The plates are incubated for 9
days in a humidified incubator at 37°C and 5% CO2. Following a
9 day-incubation, medium is removed, and cells are subjected to RNA
extraction to measure the cccDNA-dependent precore mRNA level.
MCE has not independently confirmed the accuracy of these methods. They are for reference only.