Johnson & Johnson moved deeper into in vivo CAR-T by paying $785 million upfront to partner with Sail Biomedicines, with additional milestone payments tied to development goals. The agreement also grants J&J an exclusive option to acquire Sail for $2.58 billion, positioning the company to expand its immune-mediated disease pipeline using Sail’s circular RNA approach alongside an existing lentiviral strategy. The Sail deal follows recent big-money bets across the modality, including other large pharma investments in autoimmune-focused in vivo CAR-T programs. Sail’s lead program targets CD4 and CD8 T cells in autoimmune disease, with SAIL-0839 positioned as the vanguard asset under the collaboration. By securing both a near-term partnership and a pathway to full acquisition, J&J is effectively underwriting execution risk while keeping optionality for platform-wide expansion into additional targets, a key consideration in a rapidly competitive in vivo CAR-T landscape.