Assembly Biosciences, Inc. announced data from development candidate ABI-5366, a long-acting herpes simplex virus (HSV) helicase inhibitor targeting high-recurrence genital herpes, featured in one oral and one poster presentation at the 47th Annual International Herpesvirus Workshop in Missoula, Montana, taking place July 15-19, 2023. In both the oral and poster presentation entitled "Pre-clinical characterization of ABI-5366: a highly potent long-acting helicase-primase inhibitor for the treatment of high recurrence genital herpes," data describe ABI-5366's low-nanomolar potency in vitro against both HSV-1 and HSV-2 clinical isolates. Supporting ABI-5366's potential as a long-acting therapeutic, data also demonstrate ABI-5366's high plasma clearance rates in multiple preclinical models with an extremely low projected clearance rate in humans.

Additionally, in multiple preclinical models, oral dosing or subcutaneous injection of ABI-5366 demonstrated sustained plasma concentrations for greater than one month. The presentations also include non-GLP safety data available to date supporting a favorable safety profile for ABI-5366 with high exposure margins and minimal potential for off-target effects. Assembly Bio plans to initiate a Phase 1a study for ABI-5366 in the first half of 2024.