1
|
Abstract 956: The HER2×HER3 bi-specific antibody Zenocutuzumab is effective at blocking growth of tumors driven by NRG1 gene fusions. Cancer Res 2021. [DOI: 10.1158/1538-7445.am2021-956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Fusions involving the neuregulin 1 gene (NRG1) occur at low frequency in pancreatic, lung, and other cancers. NRG1 fusion oncoproteins bind to HER3, leading to heterodimerization with HER2 and potent activation of downstream signaling mainly via the PI3K-AKT pathway. Zenocutuzumab (Zeno, MCLA-128), an ADCC-enhanced anti-HER2×HER3 bi-specific antibody, uniquely ‘docks' on HER2, to position the antibody and subsequently ‘block' NRG1 from interacting with HER3, effectively preventing HER2:HER3 heterodimerization and downstream signaling. Our goal in this study was to evaluate the efficacy of Zeno in preclinical models of NRG1 fusion-positive cancers.
We tested Zeno in a panel of isogenic and patient-derived cell line and xenograft (PDX) models of lung, breast and pancreatic cancers. Cell lines either expressed an NRG1 fusion endogenously (MDA-MB-175-VII, DOC4-NRG1) or by lentiviral transfer of cDNAs (ATP1B1-NRG1 and SLC3A2-NRG1 in H6c7 pancreatic ductal cell line; CD74-NRG1 and VAMP2-NRG1 in immortalized human bronchial epithelial cells; and DOC4-NRG1 in MCF7 breast cancer cells). PDX models were generated from NSCLC samples harboring CD74-NRG1 (ST3204) or SLC3A2-NRG1 (LUAD-0061AS3) fusions and from a high grade serous ovarian cancer harboring a CLU-NRG1 fusion (OV-10-0050). Zeno treatment of NRG1 fusion-expressing breast, pancreatic, and lung cancer cell lines resulted in dose-dependent reduction of growth and abrogated phosphorylation of HER3, HER4, AKT, p70S6 kinase and STAT3 in all cell lines tested. Phosphorylation of HER2, EGFR and MEK/ERK was inhibited, albeit with some variation, in a cell line-specific manner. Growth of isogenic control cell lines without NRG1 fusion was not significantly altered. In breast and lung cancer cell lines, Zeno treatment down-regulated cyclin D1 expression and induced expression of the negative cell cycle regulators P21 or P27. Evidence of apoptosis activation (cleaved PARP, expression of BIM and PUMA) was also observed in cells exposed to Zeno. Treatment of mice bearing LUAD-0061AS3, ST3204 and OV-10-0050 PDX tumors (2.5, 8, 25 mg/kg, QW) caused a dose-dependent inhibition of tumor growth, with tumor shrinkage observed at higher doses. Finally, we assessed the ability of Zeno to induce antibody-dependent cellular cytotoxicity using a chromium release assay and peripheral blood mononuclear cells. Zeno induced significant cytotoxicity in MDA-MB-175-VII cells while a non-ADCC enhanced, non-specific IgG had no effect.
Here we show that Zeno effectively blocks the growth of NRG1 fusion-positive cell line and xenograft models of tumors arising from lung, pancreas and other organs, and these results support the continued development of Zeno to treat patients with this molecularly defined subset of cancers.
Citation Format: Igor Odintsov, Inna Khodos, Madelyn Espinosa-Cotton, Allan J. Lui, Marissa Mattar, Alison M. Schram, Ron C. Schackmann, Jeroen Lammerts van Bueren, Cecile A. Geuijen, Elisa de Stanchina, Marc Ladanyi, Romel Somwar. The HER2×HER3 bi-specific antibody Zenocutuzumab is effective at blocking growth of tumors driven by NRG1 gene fusions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 956.
Collapse
|
2
|
Abstract 5675: Single-cell mass cytometry of classical Hodgkin lymphoma defines an exhausted and immunosuppressive microenvironment. Cancer Res 2018. [DOI: 10.1158/1538-7445.am2018-5675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: In classical Hodgkin lymphoma (cHL), the rare malignant Hodgkin Reed-Sternberg (HRS) cells are surrounded by an inflammatory infiltrate. Yet, the host anti-tumor immune response is ineffective. HRS cells have multifaceted mechanisms to evade the immune system including 9p24.1/PD-L1/PD-L2 genetic alterations leading to overexpression of PD-1 ligands and subsequent T cell exhaustion, aberrant antigen presentation and modulation of the tumor microenvironment (TME).
The clinical success of PD-1 blockade in cHL suggests the TME contains reversibly exhausted T-effectors (Teff). Paradoxically, durable responses are observed in patients with β2M/MHC class I loss on HRS cells, raising the possibility of non-CD8+ mediated mechanisms of efficacy of PD-1 blockade. For this reason, we sought to characterize HRS cells and the surrounding TME.
Methods: Using CyTOF technology, we evaluated 7 primary cHL suspensions and 10 reactive lymphoid tissue (RLT) samples at the single-cell protein level. We designed a custom panel of 39 isotope-conjugated antibodies. A combination of surface and intracellular markers distinguish T cell subsets according to lineage, differentiation, polarization, activation and exhaustion. Additional markers were incorporated to identify B cells, NK cells and macrophages. HRS cells were defined by CD15/CD30/Pax5 positivity. Inclusion of β2M and MHC class I allowed assessment of antigen presentation on HRS cells.
The data was acquired on a Helios CyTOF and analyzed using a fast k-weighted nearest neighbor algorithm, X-shift. X-shift clustered cells with phenotypic similarities together. Then, samples were separated into cHL and RLT and the contribution of a sample to a given cluster was quantified.
Results: Comparison of viable cell suspensions from RLT and cHL revealed loss of naïve T-cells and skewing towards differentiation of Teff in both CD4+ and CD8+ subsets in cHLs. This prompted a second X-shift analysis focused on CD3+ cells, which highlighted salient differences between cHL and RLT within the CD4+ subset. In cHL, we found expansion of Teff and regulatory T cells (Treg) with a reduction of follicular helper T cells. Furthermore, both Treg and Teff populations were largely Th1 (T-bet+/CCR5+) polarized. Evaluation of PD-1 expression showed Tregs had little/no PD-1 while Teff had intermediate/high expression. Hence, Tregs retain functionality in contrast to Teff, which are exhausted, providing two mechanisms of immunosuppression.
Manual gating identified HRS cells with a characteristic phenotype: CD15, CD30, Pax5, rosetted by CD4+ T cells. Importantly, we found loss or decrease of β2M and MHC class I in 5/7 cases.
Conclusions: The TME in cHL is CD4+ T cell rich with frequent loss of MHC class I on HRS cells. Differential PD-1 expression results in functional CD4+ Tregs and exhausted Teff, a synergistic bases for the observed immunosuppression in cHL.
Citation Format: Fathima Z. Cader, Ron C. Schackmann, Xihao Hu, Kirsty Wienand, Robert A. Redd, Bjoern Chapuy, Jing Ouyang, Nicole E. Paul, Evisa Gjini, Mikel Lipschitz, Laura M. Selfors, Philippe Armand, David Wu, Jonathan R. Fromm, Donna Neuberg, Xiaole S. Liu, Scott J. Rodig, Margaret A. Shipp. Single-cell mass cytometry of classical Hodgkin lymphoma defines an exhausted and immunosuppressive microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5675.
Collapse
|