Johnson & Johnson (J&J) is investing more than $785 million (approximately 1.11 trillion won) in next-generation "in vivo CAR-T" technology designed to engineer a patient’s immune cells directly inside the body. By eliminating the need to extract, modify, and expand T cells in an external laboratory, the healthcare giant aims to overcome the high costs and lengthy manufacturing timelines that currently limit conventional chimeric antigen receptor T-cell (CAR-T) therapies, while expanding the platform into autoimmune diseases.
Industry sources reported on July 30 (local time) that J&J signed a co-development agreement with SAIL Biomedicines to advance an in vivo CAR-T platform targeting immune-mediated diseases. Under the terms of the deal, J&J will pay $785 million upfront, which includes $465 million (about 660 billion won) to acquire an equity stake in SAIL. SAIL remains eligible to receive up to $140 million (about 200 billion won) in development milestone payments. J&J also secured an exclusive option to acquire SAIL in the future for $2.58 billion (about 3.7 trillion won).
Overcoming the Drawbacks of Traditional CAR-T Therapy
Conventional CAR-T therapy involves harvesting T cells from a patient, genetically modifying them at an off-site manufacturing facility to express receptors that target specific disease cells, and re-infusing them back into the patient. Because each treatment must be custom-manufactured for an individual patient, preparation is time-consuming and extremely costly. Patients often must also undergo preconditioning chemotherapy to deplete existing immune cells prior to receiving the infusion.
SAIL’s in vivo CAR-T technology circumvents external cell processing by performing the engineering step directly inside the patient. The platform utilizes circular ribonucleic acid (RNA) technology known as "Endless RNA" (eRNA), which carries the genetic instructions needed to produce CAR proteins. The eRNA is encapsulated in targeted nanoparticles and delivered straight to T cells in the body, prompting them to transiently express chimeric antigen receptors. SAIL leverages artificial intelligence (AI) to co-design both the eRNA sequence and the delivery vehicle.
Targeting B Cells to Drive Long-Term Autoimmune Remission
The two companies will initially prioritize SAIL’s lead in vivo CAR-T candidate for autoimmune conditions. The therapy is designed to direct T cells to eliminate B cells expressing the CD19 protein. By rapidly clearing abnormal B cells driving autoimmune pathology, the therapy aims to reset the immune system and induce durable, long-term disease remission. J&J and SAIL also plan to jointly identify follow-on programs targeting other immune-mediated disorders.
In preclinical studies, SAIL reported that its lead candidate significantly depleted B cells not only in circulating blood, but also within critical tissue reservoirs, including bone marrow and lymph nodes. If successfully translated into clinical practice, an in vivo approach could eliminate the logistical burdens of patient-specific manufacturing and preconditioning, dramatically expanding patient access.
However, because these findings remain at the preclinical stage, the safety and therapeutic efficacy of in vivo CAR-T in humans have yet to be established in clinical trials. J&J plans to combine SAIL’s proprietary eRNA and nanoparticle delivery technologies with its own global clinical development, regulatory, and commercialization capabilities to build out its portfolio of advanced therapies for immune-mediated and autoimmune diseases.
