Johnson & Johnson moved deeper into in vivo CAR T by paying $785 million to partner with Sail Biomedicines, including a $465 million equity investment and milestone payments. The agreement also grants J&J an exclusive option to acquire Sail for $2.58 billion, positioning Sail’s immune-mediated disease programs for further development under Big Pharma oversight. The collaboration is centered on Sail’s “vanguard” in vivo CAR T approach for autoimmune diseases, with the company highlighting mechanisms built around circular RNA stability and nanoparticle delivery. J&J said it will use the partnership to advance Sail’s lead program and broader platform capabilities, with incentives tied to development milestones. The deal lands in a competitive in vivo CAR T landscape that has recently drawn large bets from multiple pharmaceutical companies, underscoring how manufacturers are seeking new ways to expand immunotherapy beyond traditional ex vivo cell manufacturing.