Background Combination of Venetoclax, a BCL-2 inhibitor, and 5-Azacytidine, a hypomethylating agent, is the standard of care for patients with newly diagnosed acute myeloid leukemia (AML) who are not candidates for intensive chemotherapy.1 In addition to their anti-leukemic activity, 5-Azacytidine was shown to improve cancer cell recognition by immune effector cells through induction of stress ligand expression,2,3 and Venetoclax was described to enhance T-cell and NK-cell–mediated cytotoxicity against AML blasts [3,4]. Among attractive mediators of anti-tumor immunity, g9d2 T-cells are emerging as effector cells that harbor strong cytolytic and pro-inflammatory activities and are associated with good prognosis in cancer patients.5,6 ICT01 is a first-in-class anti-BTN3A mAb activating g9d2 T-cells and is being evaluated in a Phase 1/2a clinical study in solid tumors and hematologic malignancies (NCT04243499).7,8
Here, we explore the potential of combining ICT01 with Venetoclax and 5-Azacytidine to increase the anti-leukemic activity of g9d2 T-cells.
Methods Flow cytometry was used to assess the effects of Venetoclax and 5-Azacytidine on ICT01-mediated g9d2 T-cell activation after in vitro culture of healthy donor (HD) or patient derived PBMCs. AML cell lines’ and primary AML blasts’ sensitivity to ICT01-activated g9d2 T-cell killing was monitored after 4 or 24 hours of target:effector co-culture. Targets and/or effectors were pre-treated with Venetoclax, 5-Azacytidine or the combination. Expression of specific stress ligands upon treatment with Venetoclax, 5-Azacytidine or the combination was analyzed by flow cytometry.
Results First, we show that activation of g9d2 T-cells by ICT01 is unaltered in HD-PBMCs treated in vitro with Venetoclax or 5-Azacytidine, in naïve AML patients’ PBMCs or in PBMCs from AML patients under respective treatment. In addition, ICT01-mediated activation of g9d2 T-cells improved resistance to Venetoclax-induced cell death, which is otherwise pronounced in resting g9d2 T-cells. Next, we identified several stress ligands to be upregulated on AML cell lines and primary AML blasts upon treatment with Venetoclax, 5-Azacytidine or the combination. Consequently, pre-treatment of AML (cell lines and primary) with Venetoclax, 5-Azacytidine or the combination improved g9d2 T-cell killing capacities, which confirms previous findings on NK- and T-cells and adds further mechanistic insights. Finally, activation of g9d2 T-cells with ICT01 in combination with Venetoclax and 5-Azacytidine treatment further increased apoptosis of AML cells.
Conclusions These results demonstrate the ability of Venetoclax and 5-Azacytidine to potentiate ICT01-mediated killing of AML cells by γ9δ2 T-cells and support clinical evaluation of this combination as a novel therapeutic approach for AML patients.
DiNardo CD, Jonas BA, Pullarkat V, Thirman MJ, Garcia JS, Wei AH, Konopleva M, Döhner H, Letai A, Fenaux P, Koller E, Havelange V, Leber B, Esteve J, Wang J, Pejsa V, Hájek R, Porkka K, Illés Á, Lavie D, Lemoli RM, Yamamoto K, Yoon SS, Jang JH, Yeh SP, Turgut M, Hong WJ, Zhou Y, Potluri J, Pratz KW. Azacitidine and Venetoclax in Previously Untreated Acute Myeloid Leukemia. N Engl J Med. 2020; 383:617-629.
Gang AO, Frøsig TM, Brimnes MK, Lyngaa R, Treppendahl MB, Grønbæk K, Dufva IH, Straten PT, Hadrup SR. 5-Azacytidine treatment sensitizes tumor cells to T-cell mediated cytotoxicity and modulates NK cells in patients with myeloid malignancies. Blood Cancer J. 2014;4:e197.
Lee JB, Khan DH, Hurren R, Xu M, Na Y, Kang H, Mirali S, Wang X, Gronda M, Jitkova Y, MacLean N, Arruda A, Alaniz Z, Konopleva MY, Andreeff M, Minden MD, Zhang L, Schimmer AD. Venetoclax enhances T cell-mediated antileukemic activity by increasing ROS production. Blood. 2021; 138:234-245.
Wu HY, Li KX, Pan WY, Guo MQ, Qiu DZ, He YJ, Li YH, Huang YX. Venetoclax enhances NK cell killing sensitivity of AML cells through the NKG2D/NKG2DL activation pathway. Int Immunopharmacol. 2022; 104:108497.
Gentles AJ, Newman AM, Liu CL, Bratman SV, Feng W, Kim D, Nair VS, Xu Y, Khuong A, Hoang CD, Diehn M, West RB, Plevritis SK, Alizadeh AA. The prognostic landscape of genes and infiltrating immune cells across human cancers. Nat Med. 2015; 21:938-945.
Tosolini M, Pont F, Poupot M, Vergez F, Nicolau-Travers ML, Vermijlen D, Sarry JE, Dieli F, Fournié JJ. Assessment of tumor-infiltrating TCRVγ9Vδ2 γδ lymphocyte abundance by deconvolution of human cancers microarrays. Oncoimmunology. 2017; 6:e1284723.
De Gassart A, Le KS, Brune P, Agaugué S, Sims J, Goubard A, Castellano R, Joalland N, Scotet E, Collette Y, Valentin E, Ghigo C, Pasero C, Colazet M, Guillén J, Cano CE, Marabelle A, De Bonno J, Hoet R, Truneh A, Olive D, Frohna P. Development of ICT01, a first-in-class, anti-BTN3A antibody for activating Vγ9Vδ2 T cell-mediated antitumor immune response. Sci Transl Med. 2021; 13:eabj0835.
Wermke M, Marabelle A, Jungels C, Bono JD, Vey N, Vicier C, et al. 503 Clinical activity of ICT01, an anti-BTN3A-targeted, γ9δ2-activating mAb, alone and in combination with pembrolizumab in patients with advanced/refractory solid tumors: EVICTION trial. J Immunother Cancer. 2021; 9: A503
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