Anti-CD123 (Clone 32716) h(41BB-CD3ζ) CAR, pCDCAR1 (CAR-MZ023)

CAR Construction : 32716 scFv-28ζ

Fig.1 CD123-specific CARs can be expressed in healthy donor human T cells.

Representative phenotype of mock- and lenti-transduced T cells derived from a single healthy donor. After immunomagnetic selection and 1 cycle of expansion, CAR-modified T cells were stained with biotinylated anti-Fc or biotinylated anti-cetuximab followed by phycoerythrin-conjugated streptavidin and anti-TCRα/β, anti-CD4, or anti-CD8 and analyzed by flow cytometry. Quadrant placement is based on staining with isotype controls, and the percentage of cells falling in each quadrant is indicated.

Mardiros, A., Dos Santos, C., McDonald, T., Brown, C. E., Wang, X., Budde, L. E., ... & Forman, S. J. (2013). T cells expressing CD123-specific chimeric antigen receptors exhibit specific cytolytic effector functions and antitumor effects against human acute myeloid leukemia. Blood, The Journal of the American Society of Hematology, 122(18), 3138-3148.

CAR Construction : 32716 scFv-28ζ

Fig.2 CD123-specific CARs can be expressed in healthy donor human T cells.

Expression of indicated cell surface markers from 3 different healthy donor T-cell lines following immunomagnetic selection and 1 cycle of expansion. Data represent mean values ± standard error of the mean (SEM).

Mardiros, A., Dos Santos, C., McDonald, T., Brown, C. E., Wang, X., Budde, L. E., ... & Forman, S. J. (2013). T cells expressing CD123-specific chimeric antigen receptors exhibit specific cytolytic effector functions and antitumor effects against human acute myeloid leukemia. Blood, The Journal of the American Society of Hematology, 122(18), 3138-3148.

CAR Construction : 32716 scFv-28ζ

Fig.3 Specific cytotoxicity of CD123-CAR–expressing T cells (26292 and 32716) against 293T cells expressing either CD123 (293T-CD123) or CD19 (293T-CD19) by chromium release assay.

Data represent mean values of triplicate wells ± standard deviation (SD).

Mardiros, A., Dos Santos, C., McDonald, T., Brown, C. E., Wang, X., Budde, L. E., ... & Forman, S. J. (2013). T cells expressing CD123-specific chimeric antigen receptors exhibit specific cytolytic effector functions and antitumor effects against human acute myeloid leukemia. Blood, The Journal of the American Society of Hematology, 122(18), 3138-3148.

CAR Construction : 32716 scFv-28ζ

Fig.4 Specific cytotoxicity of CD123-CAR T cells (26292 and 32716) against the CD19+CD123+ LCL cell line and the CD19-CD123+ cell line KG1a by chromium release assay.

OKT3-expressing LCL (LCL-OKT3) and the CD19- CD123- K562 cell lines were used as positive and negative control cell lines, respectively. Data represent mean values of triplicate wells ± SD.

Mardiros, A., Dos Santos, C., McDonald, T., Brown, C. E., Wang, X., Budde, L. E., ... & Forman, S. J. (2013). T cells expressing CD123-specific chimeric antigen receptors exhibit specific cytolytic effector functions and antitumor effects against human acute myeloid leukemia. Blood, The Journal of the American Society of Hematology, 122(18), 3138-3148.

CAR Construction : 32716 scFv-28ζ

Fig.5 Cytokine release analysis of CD123-specific CAR-expressing T cells coculture with CD123-expressing tumor cell lines.

CD123 CAR T cells, or control pair-matched T cells, from 3 healthy donors were cocultured with the indicated cell lines for 24 hours at an E:T of 10:1 and the release of IFN-γ and TNF-α were quantified by Luminex multiplex bead technology. Fold elevation of IFN-γ production against KG1a compared with K562 for 26292 and 32716 were 2.3 and 19.1, respectively. Fold elevation of TNF-α production against KG1a compared with K562 for 26292 and 32716 was 5.5 and 16.5, respectively.

Mardiros, A., Dos Santos, C., McDonald, T., Brown, C. E., Wang, X., Budde, L. E., ... & Forman, S. J. (2013). T cells expressing CD123-specific chimeric antigen receptors exhibit specific cytolytic effector functions and antitumor effects against human acute myeloid leukemia. Blood, The Journal of the American Society of Hematology, 122(18), 3138-3148.

CAR Construction : 32716 scFv-28ζ

Fig.6 Activation of multiple CD4 and CD8 effector functions by CD123-specific CARs following coculture with primary AML samples.

CAR-engineered T cells were cocultured for 6 hours with 3 different primary AML patient samples and analyzed for surface CD107a expression and intracellular IFN-γ or TNF-α production. (A, bar graphs) Percentage of DAPI-CD3+CD8+ EGFRt+ cells expressing CD107a. Data represent mean values + SD. (A, pie charts) The fractions of CD3+CD8+EGFRt+ cells undergoing degranulation and producing IFN-γ and/or TNF-α are plotted in the pie charts. Percentages in each subset are indicated. (B)

Mardiros, A., Dos Santos, C., McDonald, T., Brown, C. E., Wang, X., Budde, L. E., ... & Forman, S. J. (2013). T cells expressing CD123-specific chimeric antigen receptors exhibit specific cytolytic effector functions and antitumor effects against human acute myeloid leukemia. Blood, The Journal of the American Society of Hematology, 122(18), 3138-3148.

CAR Construction : 32716 scFv-28ζ

Fig.7 Primary AML cells are specifically targeted by CD123 specific T cells.

CD123-specific T cells were cocultured for 4 hours with 51Cr labeled CD34+ primary AML samples at an E:T of 25:1. Pre-B ALL 802 is a primary patient sample double positive for CD19 and CD123.

Mardiros, A., Dos Santos, C., McDonald, T., Brown, C. E., Wang, X., Budde, L. E., ... & Forman, S. J. (2013). T cells expressing CD123-specific chimeric antigen receptors exhibit specific cytolytic effector functions and antitumor effects against human acute myeloid leukemia. Blood, The Journal of the American Society of Hematology, 122(18), 3138-3148.

CAR Construction : 32716 scFv-28ζ

Fig.8 CD123 CAR T cells exhibit antileukemic effects in vivo.

Bioluminescent imaging prior to T-cell treatment (day 4), on day 12, and on day 33 following KG1a-GFP-firefly luciferase transplantation.

Mardiros, A., Dos Santos, C., McDonald, T., Brown, C. E., Wang, X., Budde, L. E., ... & Forman, S. J. (2013). T cells expressing CD123-specific chimeric antigen receptors exhibit specific cytolytic effector functions and antitumor effects against human acute myeloid leukemia. Blood, The Journal of the American Society of Hematology, 122(18), 3138-3148.

CAR Construction : 32716 scFv-28ζ

Fig.9 CD123 CAR T cells exhibit antileukemic effects in vivo.

Bioluminescent signal for each treatment group over time. Dotted line represents day of T-cell treatment. Data represent mean values of each group +/- SD. Results represent pooled data from 2 separate experiments. PBS n=3; CD19R, 26292, 32716 n=6.

Mardiros, A., Dos Santos, C., McDonald, T., Brown, C. E., Wang, X., Budde, L. E., ... & Forman, S. J. (2013). T cells expressing CD123-specific chimeric antigen receptors exhibit specific cytolytic effector functions and antitumor effects against human acute myeloid leukemia. Blood, The Journal of the American Society of Hematology, 122(18), 3138-3148.

CAR Construction : 32716 scFv-28ζ

Fig.10 CD123 CAR T cells exhibit antileukemic effects in vivo.

Summary of leukemic cell engraftment in mouse peripheral blood 32 days after leukemia transplant. The percentage of viable human CD45+GFP+ KG1a cells is indicated. Each symbol indicates 1 mouse; bars represent mean values, and mean values for each group are indicated.

Mardiros, A., Dos Santos, C., McDonald, T., Brown, C. E., Wang, X., Budde, L. E., ... & Forman, S. J. (2013). T cells expressing CD123-specific chimeric antigen receptors exhibit specific cytolytic effector functions and antitumor effects against human acute myeloid leukemia. Blood, The Journal of the American Society of Hematology, 122(18), 3138-3148.

CAR Construction : 32716 scFv-28ζ

Fig.11 CD123 CAR T cells exhibit antileukemic effects in vivo.

Kaplan-Meier analysis of survival for each group (PBS n 5 3, CD19R n=4, CD123-specific n=10). Log-rank (Mantel-Cox) tests were used to perform statistical analyses of survival between groups. *P <0.05.

Mardiros, A., Dos Santos, C., McDonald, T., Brown, C. E., Wang, X., Budde, L. E., ... & Forman, S. J. (2013). T cells expressing CD123-specific chimeric antigen receptors exhibit specific cytolytic effector functions and antitumor effects against human acute myeloid leukemia. Blood, The Journal of the American Society of Hematology, 122(18), 3138-3148.