Assembly Biosciences reports interim results from phase 1b study of ABI-5366

Assembly Biosciences (ASMB) announced positive interim antiviral activity, clinical outcomes, safety and pharmacokinetic results from a Phase 1b study evaluating ABI-5366 in participants seropositive for HSV type 2 with recurrent genital herpes. For the powered antiviral endpoint, HSV-2 shedding rate, highly potent antiviral activity was observed with a 94% reduction compared to placebo over the 29-day evaluation period in the cohort evaluating a 350 mg weekly dose. This reduction exceeds Assembly Bio’s target for the study of an 80%-85% reduction in the rate of HSV-2 shedding. For a secondary clinical endpoint of genital lesion rate, a 94% reduction compared to placebo was observed with the 350 mg weekly dose. The rate of samples with high viral load, a potential surrogate for HSV-2 transmission and a secondary endpoint, was reduced by 98% compared to placebo in this cohort. ABI-5366 was observed to be well-tolerated at oral doses up to 350 mg weekly in participants seropositive for HSV-2 with recurrent genital herpes. Under the collaboration agreement between Assembly Bio and Gilead Sciences (GILD), Gilead has the right to opt in to an exclusive license for further development and commercialization of the helicase-primase inhibitor program after reviewing the option data package to be delivered by Assembly Bio following completion of the Phase 1b studies