Third Arc Bio licensed Adagene’s Safebody platform in a deal worth up to $840 million to generate two masked CD3 T‑cell engagers against tumor‑associated antigens. The agreement grants Third Arc rights to advance conditionally active bispecifics designed to reduce off‑tumor toxicity. The Safebody technology masks antigen‑binding sites and selectively unmasks them in the tumor microenvironment, a strategy intended to improve therapeutic index for CD3 redirectors. The licensing terms include upfront and milestone payments plus potential royalties, aligning with current investor interest in next‑generation T‑cell engagers. Expect both partners to prioritize preclinical safety, tumor selectivity and manufacturability as they advance candidate molecules toward IND enabling studies.