[CD19-targeted in vivo CAR-T cell therapy for high-risk/refractory B-acute lymphoblastic leukemia: a case report and literature review].

Abstract

Objective: To evaluate the safety, pharmacokinetic profile, and preliminary efficacy of a novel lentiviral-based CD19-targeted in vivo chimeric antigen receptor T (CAR-T) cell therapy in a patient with multiply relapsed/refractory B-acute lymphoblastic leukemia (B-ALL) . Methods: A 28-year-old patient with B-ALL at the 920th Hospital of Joint Logistics Support Force, received a single intravenous infusion of a lentiviral-based CD19-targeted in vivo CAR-T product at a dose of 7×10(8) TU. The safety and pharmacokinetic profiles and disease response data were collected and analyzed. Additionally, the outcomes of the current clinical studies on vivo CAR-T cell therapy were reviewed. Results: The patient with high-risk and heavily pretreated B-ALL achieved minimal residual disease negative complete remission by day 16 post infusion, which was sustained until day 50 and enabled subsequent hematopoietic stem cell transplantation. The adverse events mainly consisted of an acute inflammatory reaction within 24 hours after infusion and cytokine release syndrome during the CAR-T expansion phase. Pharmacokinetic monitoring detected peripheral blood CAR-T cells on day 6, with a peak level of 8 629.38 cells/μl on day 14. Literature review suggested that clinical research on in vivo CAR-T cell therapy remains at an early stage, with limited evidence available, and that no prior clinical outcomes of its application in B-ALL patients were reported. Conclusion: CD19-targeted in vivo CAR-T cell therapy demonstrated manageable safety and robust in vivo expansion in our patient, enabling rapid remission and creating a critical window for transplantation. Our case preliminarily supports the feasibility and potential clinical value of in vivo CAR-T cell therapy in high-risk, heavily pretreated B-ALL patients and provides a valuable practical reference for clinical application.