ASSEMBLY BIOSCIENCES, INC.

We are a biotechnology company developing innovative therapeutics targeting serious viral diseases with the potential to improve the lives of patients worldwide. Our pipeline includes multiple clinical-stage investigational therapies, including: (1) two long-acting helicase-primase inhibitors (HPIs) for the treatment of recurrent genital herpes; (2) an orally bioavailable hepatitis delta virus (HDV) entry inhibitor; and (3) a highly potent next-generation capsid assembly modulator (CAM) designed to disrupt the replication cycle of hepatitis B virus (HBV) at several key points. Our pipeline also includes a novel, oral broad-spectrum non-nucleoside polymerase inhibitor (NNPI) for the treatment of transplant-related herpesviruses, which is currently undergoing studies to enable a regulatory filing, and we have additional research programs against multiple antiviral targets. In December 2025, pursuant to our collaboration (Gilead Collaboration) with Gilead Sciences, Inc. (Gilead), Gilead exercised its option to license our HPI program for the treatment of recurrent genital herpes, including our long-acting investigational candidates ABI-1179 (1179) and ABI-5366 (5366). For additional information regarding Gilead’s exercise of its option, see Collaboration and License Agreement Gilead Sciences, Inc. Option Exercise.