mRNA-encoding CD19-targeting T cell engager for refractory immune thrombocytopenia.

mRNA-encoded CD19-targeting T cell engager achieves complete B cell depletion and durable platelet recovery in refractory immune thrombocytopenia with minimal safety concerns.

• Why it matters: Effective and safe treatments for B cell-mediated autoimmune diseases like immune thrombocytopenia are limited, and current therapies face challenges in safety and durability.
• What they did: Researchers developed ABO2203, a lipid nanoparticle-formulated mRNA encoding a CD19-targeting TCE, tested in mice and a first-in-human study with three patients, showing rapid B cell depletion and clinical improvement.
• The result: ABO2203 was well tolerated, caused sustained B cell depletion and platelet recovery for at least 6 months, and demonstrated that mRNA-encoded TCEs can be a potent, safer alternative for autoimmune B cell diseases.