July 30, 2026 —
Johnson & Johnson has entered into a collaboration with Sail Biomedicines, a Flagship Pioneering company, to advance in vivo CAR-T therapies for immune-mediated diseases.
Under the agreement, Johnson & Johnson will provide $785 million in initial payments, including a $465 million equity investment in Sail. The biotech is also eligible to receive up to $140 million in development-based milestones, bringing the initial deal value to as much as $925 million.
The agreement also gives Johnson & Johnson an exclusive option to acquire Sail Biomedicines for an additional $2.58 billion. Johnson & Johnson has not disclosed a specific timeline for exercising the option, nor has it confirmed that an acquisition will take place.
Sail is developing a platform designed to deliver genetic instructions directly to target cells inside the body, enabling patients to generate their own CAR-T constructs in vivo. This approach aims to avoid the need for conventional ex vivo CAR-T manufacturing, in which patient cells are collected, genetically engineered outside the body, expanded, and reinfused.
Sail’s platform is based on endless RNA, a technology intended to maintain protein expression longer than conventional mRNA. According to the company, this may improve dose potency and support therapeutic activity across a broader range of diseases and protein types.
Johnson & Johnson plans to use Sail’s technology to develop therapies for immune-mediated diseases and strengthen its position in immune system reprogramming and immune reset. The company has not yet disclosed the specific autoimmune or inflammatory conditions targeted under the partnership.
The collaboration will also include work on Sail’s lead autoimmune disease program, although limited details about that candidate have been publicly disclosed.
Johnson & Johnson is already a major participant in the CAR-T field through Carvykti, its FDA-approved multiple myeloma therapy developed with Legend Biotech. However, Sail represents Johnson & Johnson’s first publicly disclosed major move into the emerging in vivo CAR-T modality.
In vivo CAR-T approaches are attracting increasing attention because they could simplify cell therapy delivery, reduce time to treatment, lower manufacturing complexity, and expand access compared with current ex vivo CAR-T therapies.
The transaction follows broader pharmaceutical investment in in vivo CAR-T platforms, including recent acquisitions and partnerships by companies such as Eli Lilly, AbbVie, and AstraZeneca. As the field advances, key questions will include delivery precision, durability of CAR expression, safety, repeat dosing, and whether in vivo-generated CAR-T cells can achieve clinical activity comparable to conventional cell therapies.
