Astellas Pharma terminated its multi‑target collaboration with CytomX that originally carried up to $1.6–$1.7 billion in milestones. The partnership—launched in 2020 to apply CytomX’s Probody platform to generate T‑cell engaging bispecifics—had narrowed to select targets; Astellas elected to halt IND‑enabling work on the initial program and prioritize a second target before electing to end the alliance. CytomX said it will evaluate options to advance select targets internally following the split. Financial terms underlying the termination were not fully disclosed beyond the original deal structure and prior milestone payments. The move highlights the risk of long‑tail, milestone‑dependent biobucks collaborations when strategic priorities shift at large pharmas; smaller partners must weigh contingency plans for program continuity and alternative funding or partnering routes.