Pharma BD Deal Intelligence
Gilead Sciences exercised its option on 22 December 2025 to license Assembly Biosciences' herpes simplex virus helicase-primase inhibitor programs, covering the Phase 1 oral candidates ABI-5366 and ABI-1179, for recurrent genital herpes. These are the first programs Gilead has taken forward under the companies' ongoing R&D collaboration. Interim Phase 1b data showed antiviral activity and reductions in virus-positive lesions, with pharmacokinetics supporting once-weekly oral dosing. Assembly Bio is eligible for up to approximately USD 365 million in option, milestone and related payments.