CD19-CAR-T cell immunotherapy for refractory/relapse B-ALL patients could result in high CRCR:complete remission /incomplete count recovery (CRiCRi:incomplete count recovery) rate including extramedullary leukemia.
Elimination of diffuse EMDsEMDs:extramedullary diseases in one patient:
(a) Whole body scans that demonstrated leukemia lesions in a patient by PET/CT. After CAR-T cell therapy the EMDs is almost be cleared.
(b) A leukemia lesion in the liver before (left panel) and after CAR-T cell therapy (right panel), detected by PET/CT. After CAR-T cell therapy the EMDs is almost be cleared.
(c) A leukemia lesion in the kidney before (left panel) and after CAR-T cell therapy (right panel), detected by PET/CT.
Arrows indicate leukemia lesions. After CAR-T cell therapy the EMDs is almost be cleared.
(a) Survival curve of patients received allo-HCT. The 6-month LFSLFS:leukemia-free survival after HCT was 81.3%.
(b) Relapse and TRMTRM:treatment related mortality in patients received allo-HCT. The 6-month relapse rate after HCT was 11.9%. The 6-month TRM after HCT was 7.7%.
Our paper High efficacy and safety of low-dose CD19-directed CAR-T cell therapy in 51 refractory or relapsed B acute lymphoblastic leukemia patients was published in the journal Leukemia.
Modified second generation CAR-T therapy in our hospital Completed more than 500 cases:
• Less CAR-T cells infusion can reduce the cost and CRS severity but a threshold dosage for CAR-T cell infusion is required to in vivo expansion and therapeutic efficacy.
• The CRS severity is related to the leukemia burden and the numbers of infused CAR-T cells.
• CAR-T cell transduction efficiency and viability are negatively related to the leukemia burden in BMBM:bone marrow.
• CD19 negative relapse has been observed.
• Resulted in high CR/CRi/CMR rate (92 pts with 90% CR/CRi, 100% in most recent 40 cases).
• The response can be achieved with less CAR-T cells ( 1×105/kg).
• Bridge to allo-HSCT may improve the cure rate (84% CCR upto now by allo-HSCT after CAR-T with median observation 200 days).