Assembly Biosciences Secures $35M for HPI Program, Cash Runway Into 2028
Assembly Biosciences licensed its helicase-primase inhibitor program (ABI-5366 and ABI-1179) to Gilead for a $35 million option fee after positive Phase 1b data and reported year-end cash of $248.1 million, funding operations into 2028. Collaborative research revenue rose to $72.3 million, net loss narrowed to $6.1 million.
1. HPI Program Licensed to Gilead
Assembly Biosciences licensed its helicase-primase inhibitor program, including candidates ABI-5366 and ABI-1179, to Gilead after positive Phase 1b interim data from weekly and monthly dosing cohorts. The agreement yielded a $35 million option fee and validates the company’s long-acting oral antiviral approach.
2. Year-End Financial Results
As of December 31, 2025, Assembly held $248.1 million in cash, cash equivalents and marketable securities, up from $112.1 million a year earlier, providing runway into 2028. Collaborative research revenue with Gilead rose to $72.3 million in 2025, while net loss narrowed to $6.1 million from $40.2 million in 2024.
3. Pipeline Advancement and Milestones
The company anticipates initiating a Phase 2 study of ABI-6250, its oral entry inhibitor for chronic HDV, by the end of 2026 and expects to decide by mid-2026 whether to opt into a 40% U.S. cost–profit share for the herpes HPI program. After Gilead declined its option on ABI-4334, Assembly regained sole rights and launched a partner search process.