Checkpoint Blockade in Combination with CD33 Chimeric Antigen Receptor T Cell Therapy and Hypomethylating Agent Against Acute Myeloid Leukemia
| العنوان: | Checkpoint Blockade in Combination with CD33 Chimeric Antigen Receptor T Cell Therapy and Hypomethylating Agent Against Acute Myeloid Leukemia |
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| المؤلفون: | Marissa Del Real, Tongyuan Xue, David Horne, Sonia Maryam Setayesh, Candida Toribio, Lihua E. Budde, Emanuela Marcucci, Stephen J. Forman |
| المصدر: | Blood. 134:1383-1383 |
| بيانات النشر: | American Society of Hematology, 2019. |
| سنة النشر: | 2019 |
| مصطلحات موضوعية: | 0301 basic medicine, Myeloid, business.industry, T cell, medicine.medical_treatment, Immunology, Decitabine, Cell Biology, Hematology, Immunotherapy, Biochemistry, 03 medical and health sciences, 030104 developmental biology, 0302 clinical medicine, medicine.anatomical_structure, Antigen, Hypomethylating agent, medicine, Cancer research, Cytotoxic T cell, Chimeric Antigen Receptor T-Cell Therapy, business, 030215 immunology, medicine.drug |
| الوصف: | Acute myeloid leukemia (AML) is the most common acute leukemia in adults. The cure rate for primary AML patients is only 35% and decreases with age. Novel and effective immunotherapies for patients with relapsed and/or refractory (r/r) AML remain an urgent unmet need. CD33 is an attractive immunotherapeutic target for myeloid malignancies given its expression on more than 85% of AML patient samples. We therefore set out to design and test CD33 chimeric antigen receptor (CD33CAR) T cells preclinically as a single agent and in combinational therapy. To assess antileukemic responses of CD33CAR T cells in vitro and in vivo, we enriched CD4/CD8 T cells from peripheral blood mononuclear cells (PBMCs) and genetically modified them to express a second-generation CD33CAR. CD33CAR T cells exhibited potent antigen dependent CD107a degranulation, IFN-γ production and killing activities against AML cells in vitro. Using a NOD-SCID-IL2Rgnull (NSG) xenograft model engrafted with MOLM-14-ffluc, a CD33 expressing AML cell line transduced with lentivirus carrying firefly luciferase (ffluc) and enhanced green fluorescent protein (eGFP), 3 million CD33CAR or mock T cells were introduced intravenously. CD33 CAR T cell-treated group displayed 98.2% leukemic regression 4 days post CAR T infusion, and 99.6% reduction on day 31. Bioluminescent imaging (BLI) and Kaplan-Meier analysis demonstrated that CD33CAR T cells significantly decreased leukemic burden and prolonged overall survival compared to mock T cells in vivo. Decitabine, a DNA hypomethylating agent (HMA), is a main therapeutic agent for treating AML. We observed HMA treatment led to increased CD33 expression on MOLM-14 cells in vitro. We hypothesized that decitabine can potentiate CD33CAR T cell-mediated AML killing by increasing CD33 expression. MOLM-14 cells were treated with either decitabine alone, CD33CAR T cells alone, or sequential treatment using various concentrations of decitabine or DMSO followed by CD33CAR or mock T cells in an E:T ratio of 1:100. We determined the target specific killing activities in each group using flow cytometric based analysis 48 and 96 hours later. The decitabine followed by CD33CAR T cells treatment reproducibly resulted in the most robust antileukemic activity with 80.6% MOLM-14 cells killed. In comparison, CD33CAR T cells or decitabine monotherapy resulted in 11.5% and 50.9% killing, respectively. In vivo testing of the combinational effects of decitabine and CD33CAR T cells are underway and will be updated at the meeting. Finally, checkpoint blockade targeting programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) has shown survival benefits, particularly in combination with HMA, for patients with r/r AML (Daver et al. 2019). We observed elevated PD-L1 expression on residual AML blasts that survived the treatment with decitabine in combination with CD33CAR T cells. Therefore, we hypothesized that blockade of PD-1/PD-L1 interaction might further improve the antileukemic effect of CD33CAR T cells against AML cells post antigen induction by decitabine. MOLM-14 cells were treated with decitabine for 2 days and CD33CAR T cells were added in an E:T ratio of 1:75. Anti-PD-1 or IgG4 antibody was added to the culture at various concentrations. The most robust CD33 specific killing was seen in the culture with anti-PD-1 antibody added. Further characterization are underway and will be presented. Taken together, our preclinical findings have demonstrated the potency of the CD33CAR T cell therapy and ways to optimize its efficacy. Our results support clinical translation of CD33CAR T cells for patients with AML. Disclosures Budde: F. Hoffmann-La Roche Ltd: Consultancy. |
| تدمد: | 1528-0020 0006-4971 |
| DOI: | 10.1182/blood-2019-121486 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::4ae52ef8b7f70049f078b146ab7e23df https://doi.org/10.1182/blood-2019-121486 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi...........4ae52ef8b7f70049f078b146ab7e23df |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15280020 00064971 |
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| DOI: | 10.1182/blood-2019-121486 |