LB80331

LB80331 is a **nucleotide analog** that acts as the active metabolite of LB80380, an orally administered dipivoxil ester prodrug developed as a novel antiviral agent for chronic hepatitis B (CHB)[1][2][3]. After administration, LB80380 is converted into LB80331 in the liver and intestine by deacetylation and then further metabolized to LB80317 by oxidation of the nucleoside base at the 6 position[1][2][3]. Both LB80331 and LB80317 are subsequently phosphorylated, and the phosphorylated forms inhibit hepatitis B virus (HBV) replication by incorporation into viral DNA, leading to chain termination[1][2]. The pharmacokinetic profile in patients suggests rapid absorption of LB80380 and conversion to LB80331, with a half-life of 2.5–3.3 hours for LB80331 and a significantly longer half-life (45–62 hours at steady-state) for LB80317, supporting potential once-daily dosing[1][2][3]. LB80380/LB80331 is structurally related to adefovir and tenofovir, and is effective against lamivudine- and other nucleoside/nucleotide-resistant HBV strains[1]. Most excretion is via urine (~80%)[1]. The principal development indication is chronic hepatitis B.