Johnson & Johnson and Sail Biomedicines extended momentum in the in vivo CAR T race through a structured collaboration built around Sail’s delivery and expression engineering. The agreement, which includes a $785 million upfront payment and acquisition option, underscores how large pharma is betting on immune “reset” strategies for autoimmune indications. Sail’s approach combines platform components designed to drive targeted expression in vivo, with the collaboration intended to advance Sail’s vanguard autoimmune disease program. The deal also highlights how the modality is being positioned as an alternative to ex vivo cell collection, which can be more complex to scale. As competitors pursue parallel in vivo CAR T and related immune engineering platforms, deal structures with acquisition options are becoming common tools for managing technical and clinical risk while capturing strategic upside.