Evolution to plasmablastic lymphoma evades CD19-directed chimeric antigen receptor T cells

Area of Science:

• Oncology
• Immunotherapy
• Hematology

Background:

• Chronic lymphocytic leukemia (CLL) with Richter transformation is an aggressive malignancy.
• Chimeric antigen receptor (CAR)-T cell therapy targeting CD19 shows promise but faces challenges.
• Lymphoma cells can evade targeted therapies through differentiation.

Purpose of the Study:

• To investigate the mechanisms of relapse in a patient treated with CD19-targeted CAR-T cells.
• To analyze the evolution of lymphoma post-therapy.
• To understand the challenges of antigen-directed immunotherapy.

Main Methods:

• Case study of a patient with relapsed/refractory CLL and Richter transformation.
• Treatment with CD19-targeted CAR-T cells.
• Molecular genetic evaluation of relapsed disease.

Main Results:

• Patient relapsed with CD19-negative plasmablastic lymphoma.
• Loss of B cell differentiation markers observed.
• Multiple independent lines of CD19-negative disease evolved.
• Lymphoma plasticity demonstrated evasion of targeted therapy.

Conclusions:

• Mature lymphomas can evade CD19-targeted CAR-T cell therapy by differentiating.
• Plasticity of lymphoma poses challenges for antigen-directed immunotherapy.
• Engineered T cells exert selective pressure, driving therapeutic resistance.