SAIL-0839

SAIL-0839 is an investigational, off-the-shelf, in vivo CAR-T cell therapy being developed by Sail Biomedicines in collaboration with Johnson & Johnson for the treatment of autoimmune and immune-mediated diseases, including systemic lupus erythematosus and rheumatoid arthritis. The therapeutic candidate utilizes Sail's proprietary endless RNA (eRNA) technology—a circularized mRNA platform designed for enhanced stability and durable protein expression—encapsulated within programmable, targeted nanoparticles. Upon intravenous administration, the nanoparticles selectively target and deliver the eRNA payload to endogenous CD4+ and CD8+ T cells directly inside the patient's body. This in vivo reprogramming coaxes the T cells to express a chimeric antigen receptor (CAR) targeting CD19, leading to the depletion of pathogenic B cells and a reset of the immune system. By engineering CAR-T cells in situ, SAIL-0839 aims to bypass the complex manufacturing, high costs, and toxic lymphodepleting preconditioning regimens associated with conventional ex vivo CAR-T therapies.