Assembly Biosciences, Inc. provided an update on its investigational next-generation hepatitis B virus (HBV) core inhibitors, ABI-H3733 (3733) and ABI-4334 (4334), and reported financial results and recent highlights for the fourth quarter and year ended December 31, 2022. Phase 1a clinical trial is a randomized, blinded and placebo-controlled study evaluating the safety, tolerability and PK of 4334 following single ascending dose and multiple ascending dose administration in healthy subjects. The objectives of the study include assessment of the proportion of subjects with AEs, premium treatment discontinuation due to AEs and abnormal laboratory results.

Dosing has been completed for all subjects in all single-dose cohorts (30 mg, 100 mg, 200 mg and 400 mg) and both multiple-dose cohorts of 100 mg and 200 mg, with data pending for the 200 mg multiple-dose cohort. Based on data available for the single-dose and 100 mg multiple-dose cohorts through March 21, 2023, 4334 continued to show a half-life supportive of once-a-day (QD) dosing. A dose of 200 mg was selected for the second and final multiple-dose cohort.

Dosing for this cohort is complete and data from this cohort are anticipated in April. 4334 was internally discovered and developed by Assembly Bio and designed to optimize potency against both new virus production and formation of cccDNA, the viral reservoir, and has a distinct chemical scaffold from 3733. Phase 1b Study for 3733 (Study ABI-H3733-102 and Nonclinical Toxicology Studies) The ongoing Phase 1b clinical trial is a randomized, multi-center, double-blind and placebo-controlled study evaluating The safety, potency and other viral parameters associated with 3733 treatment in adults with cHBV infection who are treatment naive or off treatment.

Patients were treatment naive or off treatment. patients were treatment naive or off treatment".