Superior Therapeutic Index in Lymphoma Therapy: CD30(+) CD34(+) Hematopoietic Stem Cells Resist a Chimeric Antigen Receptor T-cell Attack.
Recent clinical trials with chimeric antigen receptor (CAR) redirected T cells targeting CD19 revealed particular efficacy in the treatment of leukemia/lymphoma, however, were accompanied by a lasting depletion of healthy B cells. We here explored CD30 as an alternative target, which is validated in lymphoma therapy and expressed by a broad variety of Hodgkin's and non-Hodgkin's lymphomas. As a safty concern, however, CD30 is also expressed by lymphocytes and hematopoietic stem and progenitor cells (HSPCs) during activation. We revealed that HRS3scFv-derived CAR T cells are superior since they were not blocked by soluble CD30 and did not attack CD30(+) HSPCs while eliminating CD30(+) lymphoma cells. Consequently, normal hemato- and lymphopoiesis was not affected in the long-term in the humanized mouse; the number of blood B and T cells remained unchanged. We provide evidence that the CD30(+) HSPCs are protected against a CAR T-cell attack by substantially lower CD30 levels than lymphoma cells and higher levels of the granzyme B inactivating SP6/PI9 serine protease, which furthermore increased upon activation. Taken together, adoptive cell therapy with anti-CD30 CAR T cells displays a superior therapeutic index in the treatment of CD30(+) malignancies leaving healthy activated lymphocytes and HSPCs unaffected.
Center for Molecular Medicine Cologne, University of Cologne, and Department I for Internal Medicine, University Hospital Cologne, Cologne, Germany.
Andreas A
AA
Hombach
Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
André
A
Görgens
Center for Molecular Medicine Cologne, University of Cologne, and Department I for Internal Medicine, University Hospital Cologne, Cologne, Germany.
Markus
M
Chmielewski
Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Florian
F
Murke
Division of Virology, Medical University of Innsbruck, Innsbruck, Austria.
Janine
J
Kimpel
Institute for Transfusion Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
Bernd
B
Giebel
Center for Molecular Medicine Cologne, University of Cologne, and Department I for Internal Medicine, University Hospital Cologne, Cologne, Germany.
Hinrich
H
Abken