T cell immunotherapies are promising options in leukemia, among which the CD19/CD3-bispecific T cell engager antibody blinatumomab (MT103) has shown high response rates at very low doses in patients with lymphoma.
In this regard, CD19-specific CAR T cell therapies have achieved dramatic objective responses for a high percent of patients with CD19-positive leukemia or lymphoma.
The aim of this article is to provide consensus opinion from experts in the fields of hematopoietic cell transplantation, cellular immunotherapy, and lymphoma regarding key clinical questions pertinent to the use of CD19 CAR T cell products for the treatment of NHL.
Autologous T cells transduced with CD19-directed chimeric antigen receptors have recently been approved by several regulatory agencies for the treatment of relapsed and refractory leukemia and lymphoma, after demonstrating remarkable remission rate in advanced patients.
We conducted a clinical trial to assess the safety and efficacy of CD19-targeting CAR-T-cells in the treatment of relapsed and chemotherapy-refractory B-ALL and lymphoma.
We transduced CB-derived NK cells with a retroviral vector incorporating the genes for CAR-CD19, IL-15 and inducible caspase-9-based suicide gene (iC9), and demonstrated efficient killing of CD19-expressing cell lines and primary leukemia cells in vitro, with marked prolongation of survival in a xenograft Raji lymphoma murine model.
These data suggest that Igβ and CD19 are part of an alternative B-cell signaling module that use continuous ITAM/PI3K signaling to promote the survival of B lymphoma and normal B cells.
The remarkable clinical response rates achieved by adoptive transfer of T cells that target CD19 in patients with leukemia and lymphoma have led to a growing number of clinical trials exploring CAR T-cell therapy for solid tumors.
In CAR T cell therapy targeting CD19 for lymphoma, host immune anti-murine CAR responses limited the efficacy of repeat dosing and possibly long-term persistence.
CARCIK-CD19 showed a dose-dependent antitumor response and prolonged persistence in a PDX, bearing the feature of a Philadelphia-like ALL with PAX5/AUTS2 translocation, and in a survival model of lymphoma, achieving complete eradication of disseminated tumors.
Early trials with anti-CD19 CAR T cells have achieved spectacular remissions in B-cell leukemia and lymphoma, so far refractory, very recently resulting in the Food and Drug Administration approval of CD19 CAR T cells for therapy.