B-lymphocyte antigen CD19 or CD19 [Cluster of Differentiation 19] is a protein that is encoding by the CD19 gene and is expressed in B-cells [B-cells are a type of white blood cell]. because CD19 is expressed on all B-cells [80% of ALL, 88% of B-cell lymphomas and 100% of B-cell leukemias], it can be used to diagnose cancers that develop in B-cells, notably B-cell lymphomas, acute lymphoblastic leukaemia [ALL] and chronic lymphocytic leukaemia [CLL]. B-cell malignancies express normal to high levels of CD19.
to date, chimeric antigen receptor [CAR] T-cell therapies available target CD19- this means that the CAR T-cells infused into the patient bind with the CD19 receptors on the malignant B-cells – activating the CAR T-cell activation which results in the depletion of malignant and non malignant CD19+ B-cells.
the unprecedented activity for CD19 directed CARs has created new hope for personalized cures – creating a new option for patients who were otherwise untreatable.
CD19-directed CAR T-cells have been approved by health canada and CADTH and INESSS for use in children and young adults with ALL and in adults with relapsed or refractory [r/r] diffuse large B cell lymphoma [DLBCL], primary mediastinal large B-cell lymphoma [PMBCL] and relapsed or refractory mantle cell lymphoma [MCL]