In vivo dynamics and anti-tumor effects of EpCAM-directed CAR T-cells against brain metastases from lung cancer

ABSTRACT

Lung cancer patients are at risk for brain metastases and often succumb to their intracranial disease. Chimeric Antigen Receptor (CAR) T-cells emerged as a powerful cell-based immunotherapy for hematological malignancies; however, it remains unclear whether CAR T-cells represent a viable therapy for brain metastases. Here, we established a syngeneic orthotopic cerebral metastasis model in mice by combining a chronic cranial window with repetitive intracerebral two-photon laser scanning-microscopy. This approach enabled in vivo-characterization of fluorescent CAR T-cells and tumor cells on a single-cell level over weeks. Intraparenchymal injection of Lewis lung carcinoma cells (expressing the tumor cell-antigen EpCAM) was performed, and EpCAM-directed CAR T-cells were injected either intravenously or into the adjacent brain parenchyma. In mice receiving EpCAM-directed CAR T-cells intravenously, we neither observed substantial CAR T-cell accumulation within the tumor nor relevant anti-tumor effects. Local CAR T-cell injection, however, resulted in intratumoral CAR T-cell accumulation compared to controls treated with T-cells lacking a CAR. This finding was accompanied by reduced tumorous growth as determined per in vivo-microscopy and immunofluorescence of excised brains and also translated into prolonged survival. However, the intratumoral number of EpCAM-directed CAR T-cells decreased during the observation period, pointing toward insufficient persistence. No CNS-specific or systemic toxicities of EpCAM-directed CAR T-cells were observed in our fully immunocompetent model. Collectively, our findings indicate that locally (but not intravenously) injected CAR T-cells may safely induce relevant anti-tumor effects in brain metastases from lung cancer. Strategies improving the intratumoral CAR T-cell persistence may further boost the therapeutic success.

KEYWORDS:

• CAR T-cells
• adoptive immunotherapy
• brain metastasis
• CNS tumor
• lung cancer
• in vivo microscopy
• histology
• survival

Availability of data and materials

Coded data can be accessed upon qualified request from the authors.

Ethics approval and consent to participate, consent for publication

We take full responsibility for this original research. We also would like to confirm that this paper has not been submitted to another journal and has not been published in whole or in part elsewhere previously. I have full access to all data, and I have the right to publish any and all data. Clinical metadata was collected with IRB approval and informed consent. All authors have read and agreed to the submission of this study to Onco-Immunology and to the conditions noted on the Authorship Agreement Form.

Disclosure statement

Tao Xu, No disclosures; Philipp Karschnia, No disclosures; Bruno L. Cadilha, No disclosures; Sertac Dede, No disclosures; Michael Lorenz, No disclosures; Niklas Seewaldt, No disclosures; Elene Nikolaishvili, No disclosures; Katharina Müller, No disclosures; Jens Blobner, No disclosures; Nico Teske, No disclosures; Julika J. Herold, No disclosures; Kai Rejeski, Kite/Gilead: Research funding and travel support, Novartis: Honoraria, BMS/CELGENE: Consultancy, Honoraria; Sigrid Langer, No disclosures; Hannah Obeck, No disclosures; Theo Lorenzini, No disclosures; Matthias Mulazzani, No disclosures; Wenlong Zhang, No disclosures; Hellen Ishikawa-Ankerhold, No disclosures; Veit R. Buchholz, No disclosures; Marion Subklewe, No disclosures; Niklas Thon, No disclosures; Andreas Straube, No disclosures; Joerg-Christian Tonn, Research grants from Novocure and Munich Surgical Imaging, and Royalties from Springer Publisher Intl; Sebastian Kobold, S.K. has received honoraria from TCR2 Inc, Novartis, BMS and GSK, S.K. is an inventor of several patents in the field of immuno-oncology, S.K. received license fees from TCR2 Inc and Carina Biotech, S.K. received research support from TCR2 Inc. and Arcus Bioscience for work unrelated to the manuscript. Louisa von Baumgarten, No disclosures.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/2162402X.2022.2163781

Additional information

Funding

T.X. and W.Z. acknowledge scholarship support from (CSC). P.K. acknowledges research grants from the Friedrich-Baur-Foundation, from the “Support Program for Research and Teaching” at the Ludwig-Maximilians-University Munich, from the “Society for Research and Science at the Medical Faculty of the LMU” at the Ludwig-Maximilians-University Munich, and from the “Familie Mehdorn”-Foundation. J.B. acknowledges research grants from the Munich Clinician Scientist Program “Else-Kröner-Fresenius Forschungskolleg” and of the Medical Faculty of the Ludwig-Maximilians-University Munich. N.T. acknowledges a research grant from the “Support Program for Research and Teaching” at the Ludwig-Maximilians-University Munich. K.R. was funded by the Else Kröner Forschungskolleg (EKFK) within the Munich Clinician Scientist Program (MCSP). M.M. acknowledges funding by the (Mildred Scheel Postdoctoral Fellowship). H.I-A acknowledges the SFB 914 (project Z01). S.K. acknowledges funding from the international doctoral program ‘i-Target: immunotargeting of cancer’ (funded by the Elite Network of Bavaria), Melanoma Research Alliance (grant number Melanoma Research Alliance young investigator 409510), Marie Sklodowska-Curie Training Network for Optimizing Adoptive T Cell Therapy of Cancer (funded by the Horizon 2020 programme of the European Union; grant Horizon 2020 Framework Programme 955575), Else Kröner-Fresenius-Stiftung Else-Kröner Forschungskolleg (EKFK), German Cancer Aid., Ernst Jung Stiftung, Institutional Strategy LMUexcellent of LMU Munich (within the framework of the German Excellence Initiative), Bundesministerium für Bildung und Forschung, European Research Council (Starting Grant 756017), Deutsche Forschungsgemeinschaft (DFG), by the SFB-TRR 338/1 2021–452881907, Fritz-Bender Foundation, José Carreras Foundation and Hector Foundation. L.v.B. acknowledges support by the SFB TRR 338 (project B02) and from the advanced Munich Clinical Scientist Program”. L.v.B. and the entire ‘AG for Experimental Neuro-Oncology’ thankfully acknowledge financial research support from Marlene and Dr. Dirk Ippe; China Scholarship Council; German Cancer Aid; Elitenetzwerk Bayern.