Eradication of B-lineage cells and regression of lymphoma in a patient treated with autologous T cells genetically engineered to recognize CD19

Abstract

Adoptive transfer of genetically modified T cells is an attractive approach for generating antitumor immune responses. We treated a patient with advanced follicular lymphoma by administering a preparative chemotherapy regimen followed by autologous T cells genetically engineered to express a chimeric antigen receptor (CAR) that recognized the B-cell antigen CD19. The patient's lymphoma underwent a dramatic regression, and B-cell precursors were selectively eliminated from the patient's bone marrow after infusion of anti-CD19-CAR-transduced T cells. Blood B cells were absent for at least 39 weeks after anti-CD19-CAR-transduced T-cell infusion despite prompt recovery of other blood cell counts. Consistent with eradication of B-lineage cells, serum immunoglobulins decreased to very low levels after treatment. The prolonged and selective elimination of B-lineage cells could not be attributed to the chemotherapy that the patient received and indicated antigen-specific eradication of B-lineage cells. Adoptive transfer of anti-CD19-CAR-expressing T cells is a promising new approach for treating B-cell malignancies. This study is registered at www.clinicaltrials.gov as #NCT00924326.

Figures

Figure 1

B-lineage cells, including B-cell precursors, were eradicated from the bone marrow after treatment with anti–CD19-CAR-transduced T cells. (A) Representative pretreatment computed tomography scan images and images from 18 weeks after treatment demonstrate regression of lymphoma masses in the chest and abdomen after treatment with chemotherapy followed by anti–CD19-CAR-transduced T cells plus IL-2. (B) Flow cytometric evaluation of a pretreatment bone marrow aspirate was conducted with a forward versus side light scatter analysis gate of lymphoid cells. The left upper quadrant contains CD19+ B-lineage cells (35% of lymphoid cells), and the right lower quadrant contains CD3+ T cells. (C) Flow cytometric evaluation of a pretreatment bone marrow aspirate with a CD19+ analysis gate is shown. κ- and λ-negative, CD19+, mostly immature B-lineage cells that are not part of the malignant lymphoma clone are in the rectangle. The cells outside the rectangle are mostly lymphoma cells. (D) Flow cytometric evaluation of a pretreatment bone marrow aspirate with a forward versus side light scatter analysis gate of lymphoid cells. Immature B-cell precursors in the oval are CD22+ and CD20−. (E) Flow cytometric evaluation of a pretreatment bone marrow aspirate with a forward versus side light scatter analysis gate of lymphoid cells. Immature B-cell precursors in the polyhedral demonstrate decreasing CD10 correlating with increasing CD20 expression. (F) Flow cytometric evaluation of a bone marrow aspirate from 36 weeks after treatment with a forward versus side light scatter analysis gate of lymphoid cells. CD19+ B-lineage cells are absent. (G) Immunohistochemistry staining of a pretreatment bone marrow biopsy reveals a large population of CD19+ cells that includes lymphoma cells as well as nonmalignant B-lineage cells. (H) Immunohistochemistry staining of a bone marrow biopsy from 36 weeks after infusion of anti–CD19-CAR-transduced T cells demonstrates a complete absence of CD19+ cells. (I) High-power view of the same anti-CD19 staining shown in panel H.

Figure 2

Prolonged B-cell depletion after anti–CD19-CAR-transduced T-cell infusion. (A) Immunohistochemistry staining of a pretreatment bone marrow biopsy shows a large population of CD79a+ cells. (B) Thirty-six weeks after anti–CD19-CAR-transduced T-cell infusion, rare CD79a+ cells were detected by immunohistochemisty staining of a bone marrow biopsy. The cells did not appear to be plasma cells morphologically. The number of CD79a+ cells was substantially below normal limits. The arrow indicates one of the rare CD79a+ cells. (C) The blood B-cell count of the patient treated with anti–CD19-CAR-transduced T cells is shown before treatment and at multiple time points after treatment. B cells were measured by flow cytometry for CD19. The dashed line indicates the lower limit of normal. Day 0 is the day of the second anti–CD19-CAR-transduced T-cell infusion. (D) The mean ± SEM blood B-cell count is shown for patients who received infusions of T cells targeted to either the NY-ESO antigen or the gp100 antigen. The patients all received the same chemotherapy and IL-2 regimen as the patient who received anti–CD19-CAR-transduced T cells. NY-ESO and gp100 are not expressed by B cells. Day 0 is the day of T-cell infusion. All available B-cell counts were included for each time point (pretreatment, n = 28; 4-5 weeks after T-cell infusion, n = 29; 8-11 weeks after T-cell infusion, n = 31; 14-19 weeks after T-cell infusion, n = 20). All patients with available samples had a B-cell count in the normal range by 14 to 19 weeks after T-cell infusion. (E) The blood CD3+ T-cell count of the patient treated with anti–CD19-CAR-transduced T cells is shown before treatment and at multiple time points after treatment. (F) The blood NK cell count of the patient treated with anti–CD19-CAR-transduced T cells is shown before treatment and at multiple time points after treatment. NK cells were measured by flow cytometry as CD3−, CD16+, CD56+ cells. (E-F) Day 0 is the day of the second anti–CD19-CAR-transduced T-cell infusion, and the dashed line indicates the lower limit of normal. (G) The serum IgG level of the patient treated with anti–CD19-CAR-transduced T cells is shown before treatment and at multiple time points after treatment. Day 0 is the day of the second anti–CD19-CAR-transduced T-cell infusion. (H) Real-time polymerase chain reaction was performed with a primer and probe set that was specific for the anti-CD19 CAR. Anti–CD19-CAR-transduced T cells were undetectable in pretreatment blood samples. The anti–CD19 CAR transgene was detected in the peripheral blood of the patient who received anti–CD19-CAR-transduced T cells from 1 to 27 weeks after anti–CD19-CAR-transduced T-cell infusion.