Assembly Biosciences reports positive Phase 1a results in genital herpes

Assembly Biosciences (ASMB) announced positive interim Phase 1a results in healthy participants from its ongoing Phase 1a/b study of ABI-1179, an investigational long-acting herpes simplex virus, or HSV, helicase-primase inhibitor candidate for recurrent genital herpes. A half-life of approximately four days and high exposure across the dose range evaluated exceeded Assembly Bio’s targets for a once-weekly oral dosing profile. ABI-1179 was well-tolerated with a favorable safety profile observed. At all doses evaluated, including the lowest dose of 50 mg, ABI-1179 exceeded Assembly Bio’s target plasma concentrations for antiviral activity, a target established from pharmacokinetic modelling and projected to achieve increased efficacy compared to approved therapies. With these data, Assembly Bio plans to move directly into the Phase 1b portion of the ABI-1179 study in participants with recurrent genital herpes. Assembly Bio plans to report interim data for both candidates together in fall 2025. ABI-1179 was contributed by Gilead (GILD) under the collaboration between Assembly Bio and Gilead. ABI-1179 and ABI-5366 are investigational product candidates that have not been approved anywhere globally, and their safety and efficacy have not been established.