HBV-IN-4, a derivative of phthalazinone, functions as a potent, orally active inhibitor of HBV DNA replication, exhibiting an IC50 value of 14 nM. It effectively induces the formation of genome-free capsids, demonstrating significant anti-HBV potency[1].

HBV DNA replication:14 nM (IC50)

HBV-IN-4 (compound 19f; 0-1 μM; 8 days) treatment inhibits the various forms (relaxed circular [rc] and single-stranded [ss] HBV DNA) in a dose-dependent manner in HepG2.2.15 cells. HBV-IN-4 treatment could also reduce capsidassociated DNAs dose-dependently. HBV-IN-4 could induce the formation of genome-free capsids, including a phenotype of faster-migrating ones[1].

HBV-IN-4 (Compound 19f; 50-150 mg/kg; oral administration; twice a day; for 4 weeks; Balb/c male mice) treatment achieves 2.67 log viral load reduction in AAV-HBV/mouse model[1].HBV-IN-4 (compound 19f) exhibits favorable drug characteristics with low plasma clearance (CL=4.1 mL/min/kg), excellent drug exposure (AUC0-t=49 744 h?ng/L), T1/2 (2.15 hours) and oral bioavailability (F=60.4%) using 20 mg/kg oral administration in mice. HBV-IN-4 also shows good distribution in liver exposure[1].