Background on CD19-CAR T Cells
CAR (Chimeric Antigen Receptor) T cells are T cells that have been engineered with additional receptors to identify specific proteins, called antigens, present on the surface of other cells. CAR-enabled targeting is the basis of numerous oncology treatments in cancer, where CAR T cell therapy has shown remarkable clinical success.
Most CARs have a similar structure that includes an extracellular target binding domain derived from antibodies and an intracellular signaling domain derived from the natural T cell receptor complex. The extracellular domain is typically a single-chain variable fragment (scFv) that binds specifically to a target antigen on cancer cells, such as CD19. Since 2017, four CD19-specific CAR T cell products have achieved regulatory approval in B cell cancers, including in types of leukemia and lymphoma.
Over the past couple of years, academic groups have published findings demonstrating the potential of CD19-CAR T to transform the course of autoimmune disease. Emerging data in patients with systemic lupus erythematosus, myositis and systemic sclerosis suggests the potential of a one-time treatment with a 4-1BB-containing CD19-CAR T cell therapy, with a high degree of similarity to CABA-201, to achieve robust improvement in clinical disease activity within 3 months of treatment, with a favorable safety profile. Complete responses have been observed beyond 2 years with no relapses as of November 2023.
- Mueller F, et al. CD19-Targeted CAR-T Cells in Refractory Systemic Autoimmune Diseases: A Monocentric Experience from the First Fifteen Patients [ASH abstract].