Assembly Biosciences presented data at the 2025 ESCMID Congress on ABI-5366, a novel, long-acting helicase-primase inhibitor candidate for recurrent genital herpes, and shared new insights into the prevalence and treatment patterns of this disease. Phase 1a clinical trial data demonstrated ABI-5366’s tolerability with a half-life supporting weekly or monthly dosing. Preclinical studies confirmed its activity against both HSV-1 and HSV-2, along with tissue distribution relevant to HSV infection.
The research underscores the significant need for improved therapies for recurrent genital herpes. Current treatment options have limitations in preventing recurrences and viral transmission, highlighting the potential impact of a long-acting oral antiviral. The data presented, combined with the analysis revealing high prevalence and variable treatment patterns, strengthens the case for continued development of new treatment strategies.
Phase 1a results show ABI-5366 was well-tolerated at doses up to 350 mg, with no serious adverse events or grade 3 or 4 lab abnormalities. The observed half-life of approximately 20 days supports the potential for less frequent dosing. Preclinical data demonstrate broad activity against both HSV-1 and HSV-2 clinical isolates, reinforcing the drug’s potential for broad efficacy. A retrospective analysis estimated approximately 1.35 million individuals in the US experience recurrent genital herpes, with varying treatment approaches. Of these, roughly 57% utilize suppressive therapy and 40% episodic therapy, suggesting an opportunity for improved chronic disease management.
The positive clinical and preclinical results, along with the demonstration of the need for new treatment options, position ABI-5366 as a potential game-changer in the management of recurrent genital herpes. Interim Phase 1b results for ABI-5366 and another helicase-primase inhibitor candidate, ABI-1179, are expected in fall 2025, offering further insights into the potential of this new class of antiviral agents. This research could lead to a much-needed advancement in genital herpes treatment, offering patients a more convenient and potentially more effective long-term management strategy.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
