Gilead informed Assembly Biosciences that it would not exercise its option for the next‑generation hepatitis B capsid assembly modulator ABI‑4334, returning full rights to Assembly. The move follows a 2023 opt‑in agreement that included potential milestones; Assembly has started a structured process to find a new partner for ABI‑4334. The lead sentence: Gilead declined to expand its HBV portfolio by licensing ABI‑4334, shifting the asset back into Assembly’s sole control. Assembly said Gilead’s decision reduces potential milestone revenue but leaves Assembly free to seek new collaborations or pursue development independently. Gilead retains other HBV investments and partnerships, including therapeutic vaccine programs and marketed antivirals such as Vemlidy. The choice likely reflects Gilead’s portfolio prioritization and assessment of market and clinical risk vs. return. Assembly plans to evaluate strategic options for ABI‑4334, including partnering or advancing clinical development to preserve the asset’s value and potential in the HBV therapeutic landscape.