title: Blockade of the PD-1/PD-L1 axis augments lysis of AML cells by the CD33/CD3 BiTE antibody construct AMG 330: reversing a T-cell-induced immune escape mechanism.
abstract: Bispecific T-cell engagers (BiTEs) are very effective in recruiting and activating T cells. We tested the cytotoxicity of the CD33/CD3 BiTE antibody construct AMG 330 on primary acute myeloid leukemia (AML) cells ex vivo and characterized parameters contributing to antileukemic cytolytic activity. The E:T ratio and the CD33 expression level significantly influenced lysis kinetics in long-term cultures of primary AML cells (n=38). AMG 330 induced T-cell-mediated proinflammatory conditions, favoring the upregulation of immune checkpoints on target and effector cells. Although not constitutively expressed at the time of primary diagnosis (n=123), PD-L1 was strongly upregulated on primary AML cells upon AMG 330 addition to ex vivo cultures (n=27, P<0.0001). This phenomenon was cytokine-driven as the sole addition of interferon (IFN)-γ and tumor necrosis factor-α also induced expression. Through blockade of the PD-1/PD-L1 interaction, AMG 330-mediated lysis (n=9, P=0.03), T-cell proliferation (n=9, P=0.01) and IFN-γ secretion (n=8, P=0.008) were significantly enhanced. The combinatorial approach was most beneficial in settings of protracted AML cell lysis. Taken together, we have characterized a critical resistance mechanism employed by primary AML cells under AMG 330-mediated proinflammatory conditions. Our results support the evaluation of checkpoint molecules in upcoming clinical trials with AMG 330 to enhance BiTE antibody construct-mediated cytotoxicity.
authors.affiliation: Department of Internal Medicine III, LMU-Klinikum der Universität München, Munich, Germany.|Clinical Co-operation Group Immunotherapy at the Helmholtz Zentrum München, Munich, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Krupka
authors.affiliation: AMGEN Research (Munich) GmbH, Munich, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Kufer
authors.affiliation: AMGEN Research (Munich) GmbH, Munich, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Kischel
authors.affiliation: AMGEN Research (Munich) GmbH, Munich, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Zugmaier
authors.affiliation: Department of Internal Medicine III, LMU-Klinikum der Universität München, Munich, Germany.|Clinical Co-operation Group Immunotherapy at the Helmholtz Zentrum München, Munich, Germany.
authors.forename: F S
authors.initials: FS
authors.lastname: Lichtenegger
authors.affiliation: Department of Internal Medicine III, LMU-Klinikum der Universität München, Munich, Germany.|Clinical Co-operation Group Immunotherapy at the Helmholtz Zentrum München, Munich, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Köhnke
authors.affiliation: Department of Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany.|German Cancer Consortium (DKTK), Heidelberg, Germany.|German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Vick
authors.affiliation: Department of Gene Vectors, Helmholtz Zentrum München, German Research Center for Environmental Health, Munich, Germany.|German Cancer Consortium (DKTK), Heidelberg, Germany.|German Cancer Research Center (DKFZ), Heidelberg, Germany.|Department of Oncology, Dr von Haunersches Kinderspital, Ludwig Maximilians-Universität (LMU), Munich, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Jeremias
authors.affiliation: Department of Internal Medicine III, LMU-Klinikum der Universität München, Munich, Germany.
authors.forename: K H
authors.initials: KH
authors.lastname: Metzeler
authors.affiliation: Department of Internal Medicine III, LMU-Klinikum der Universität München, Munich, Germany.|Clinical Co-operation Group Immunotherapy at the Helmholtz Zentrum München, Munich, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Altmann
authors.affiliation: Department of Internal Medicine III, LMU-Klinikum der Universität München, Munich, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Schneider
authors.affiliation: Department of Internal Medicine III, LMU-Klinikum der Universität München, Munich, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Fiegl
authors.affiliation: Department of Internal Medicine III, LMU-Klinikum der Universität München, Munich, Germany.|German Cancer Consortium (DKTK), Heidelberg, Germany.|German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Spiekermann
authors.affiliation: AMGEN Research (Munich) GmbH, Munich, Germany.
authors.forename: P A
authors.initials: PA
authors.lastname: Bauerle
authors.affiliation: Department of Internal Medicine III, LMU-Klinikum der Universität München, Munich, Germany.|German Cancer Consortium (DKTK), Heidelberg, Germany.|German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Hiddemann
authors.affiliation: Institute for Immunology, Ludwig-Maximilians-Universität, Munich, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Riethmüller
authors.affiliation: Department of Internal Medicine III, LMU-Klinikum der Universität München, Munich, Germany.|Clinical Co-operation Group Immunotherapy at the Helmholtz Zentrum München, Munich, Germany.|German Cancer Consortium (DKTK), Heidelberg, Germany.|German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Subklewe
mesh_terms: D000818:Animals; D018033:Antibodies, Bispecific / Q000494:pharmacology*; D060890:B7-H1 Antigen / Q000032:analysis / Q000037:antagonists & inhibitors* / Q000502:physiology; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D051379:Mice; D061026:Programmed Cell Death 1 Receptor / Q000032:analysis / Q000037:antagonists & inhibitors* / Q000502:physiology; D063268:Sialic Acid Binding Ig-like Lectin 3 / Q000032:analysis; D013601:T-Lymphocytes / Q000276:immunology*; D019139:Tumor Escape / Q000187:drug effects*
chemical_list: D018033:Antibodies, Bispecific; D060890:B7-H1 Antigen; C423236:CD274 protein, human; C571163:CD33 protein, human; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor; D063268:Sialic Acid Binding Ig-like Lectin 3; C587103:AMG 330