Chimeric antigen receptor T-cell (CAR T) therapy, a life-extending treatment for patients with advanced B-cell malignancies and multiple myeloma, has now been shown to be effective for treating refractory systemic lupus erythematosus (SLE) in at least one patient.
Dr. Georg Schett
A 20-year-old woman with severe, refractory SLE, active lupus nephritis, pericarditis, and other serious symptoms had both serologic and clinical remission follow the infusion of a CAR T cell product directed against the B-cell surface antigen CD19, reported Georg Schett, MD, and colleagues from the German Center for Immunotherapy at Friedrich Alexander University Erlangen-Nuremberg in Erlangen, Germany.
“Given the role of B cells in a variety of severe autoimmune diseases, CAR T-cell therapy that targets B-cell antigens may have wider application,” they wrote in a letter to the editor of The New England Journal of Medicine.
Dr. Schett said in an email response to an interview request that the patient has remained healthy and asymptomatic without further treatment after 6 months of follow-up.
“The key question will be whether B cells return and whether these B cells will carry on to make antibodies against double-stranded DNA,” he said. “We think that the loss of B cells could be sustained given that CAR T cells are still present in the patient. The main question will be how long CAR T cells will be there and how long they deplete the B cells.”
Not just for cancer anymore
CAR T therapy involves harvesting autologous T cells and transducing them with a lentiviral vector to recognize CD19 or other B-cell surface antigens. The transduced cells are then expanded and reinfused into the patient following a lymphodepletion regimen.
There are currently five CAR T constructs approved by the Food and Drug Administration for the treatment of diffuse large B-cell lymphoma and other B-lineage lymphomas, acute lymphoblastic leukemia, multiple myeloma, and other hematologic malignancies.
For this patient, however, Dr. Schett and colleagues created their own CAR T construct rather than adapting an off-the-shelf product.
The use of this groundbreaking therapy to treat an autoimmune condition is novel, the investigators noted: “This technological breakthrough, together with recent convincing data on the role of B cells in disease pathogenesis derived from preclinical lupus models, provides a rationale for the use of CAR T-cell therapies in patients with SLE,” they wrote.
One such preclinical study was reported in Science Translational Medicine in 2019 by Marko Z. Radic, PhD, of the University of Tennessee Health Science Center in Memphis, and colleagues.
Dr. Marko Z. Radic
Those investigators generated CD19-targeted CAR T constructs and demonstrated that in mouse models of lupus, CD8-positive T cells from two different lupus strains could be successfully transfected, and that transfer of the CD19-targeting CAR T cells ablated both autoantibodies and CD19-positive cells.
“In both models, survival was remarkably extended, and target organs were spared. These exciting results could pave the way for using CD19-targeted T cells to treat patients with lupus,” they wrote.
Now, that prediction has come to fruition.
“It’s brilliant that the first case report has now been accomplished. I am fully convinced that this method will rid therapy refractory patients of their symptoms,” Dr. Radic said in an interview.