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3342 CAR T Cells and Their Immune Environment Synergize to Shape Distinct Immune Profiles in Response Versus Toxicity in B Cell Lymphoma Patients

Program: Oral and Poster Abstracts
Session: 705. Cellular Immunotherapies: Late Phase and Commercially Available Therapies: Poster II
Hematology Disease Topics & Pathways:
Research, Biological therapies, adult, Translational Research, Lymphomas, B Cell lymphoma, Chimeric Antigen Receptor (CAR)-T Cell Therapies, bioinformatics, Diseases, aggressive lymphoma, Therapies, immunology, Lymphoid Malignancies, Adverse Events, Biological Processes, Technology and Procedures, profiling, Study Population, Human, omics technologies
Sunday, December 11, 2022, 6:00 PM-8:00 PM

Stefanie Kreutmair1,2*, Maximilian M Schaefer1*, Sebastian Stolz3*, Carla Merten1*, Can Ulutekin1*, Florian Ingelfinger1*, Susanne Unger1*, Chiara Alberti1*, Tobias Wertheimer1*, Aakriti Sethi1*, Thorsten Zenz3, Markus G Manz3, Antonia Maria Susanne Müller3,4,5*, Corinne C Widmer3,5,6* and Burkhard Becher1,5*

1Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland
2German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Freiburg, Germany
3Department of Medical Oncology and Hematology, University Hospital Zurich, Zurich, Switzerland
4Department of Blood Group Serology and Transfusion Medicine, Medical University of Vienna, Vienna, Austria
5These authors contributed equally, Zurich, Switzerland
6Department of Hematology, University Hospital Basel, Zurich, Switzerland

Genetically engineered CD19-redirected chimeric antigen receptor T (CAR T) cells represent a breakthrough immunotherapy for B cell malignancies. However, response rates are variable and many patients face life-threatening side effects such as cytokine release syndrome (CRS) or immune effector cell-associated neurotoxicity syndrome (ICANS). The impact of the patient’s immune landscape as a whole - consisting of CAR T cells and non-CAR T immune cells - on patients’ outcome is largely unknown. Furthermore, reliable biomarkers to predict response and toxicity are lacking.

To decode the crosstalk of CAR T cells and their circulating immune environment, we used longitudinal, high-dimensional single-cell spectral cytometry and algorithm-guided computational analysis of 47 peripheral blood samples from 19 lymphoma patients, together with 6 healthy controls. Patient samples were harvested one day before (day -1) up to 104 days after CAR T infusion. The generated immune map, based on 69 parameters and 2078 extracted immune features, was enriched with numerous clinical parameters from the lymphoma patients, including response and toxicity data of a follow-up period ≥ 315 days.

When comparing healthy controls and B cell lymphoma patient samples at baseline (day -1 and day 0, pre-CAR T infusion), the two cohorts demonstrated distinct immune profiles, including a strong lymphodepletion and proportional expansion of the myeloid/ dendritic cell fraction in lymphoma patients.

Furthermore, this translational proteomics approach revealed a lymphoma patient-specific, heterogeneous CAR T cell population (Figure 1). However, most of the identified 13 CAR T subsets, such as γδ T cells and CD4 T regulatory cells next to naive/effector/memory T cell populations, appeared in each sample. The temporal composition of the CAR+ T population varied, presenting an inverse relationship over time with a bias of CD8 CAR T cells at early timepoints and dominating CD4 CAR T subsets later on.

When stratifying the overall immune profile at the time of CAR T cell expansion and toxicities (day 9 to 21), immune alterations associated with response to CAR T therapy (best overall response complete remission (CR)) were primarily found in the non-CAR T immune compartments, while CRS- and ICANS-associated signatures affected predominantly the CAR T population (Figure 2; deregulated immune features: p < 0.5 and wilcoxon effect size > 0.6). In particular, higher expression of TCF1 in CD8 CAR T cells and EOMES in CD8 T stem cell memory (Tscm) cells - suggestive for stem-like features that allow expansion/long-term persistence – and CD223 (LAG3) in CD4 CAR T cells marked the immune profile of CR patients. The interplay of CAR T and non-CAR T immune alterations was even more striking in toxicity: both CRS and ICANS were linked to a dysbalance in the CD226/TIGIT-axis with higher expression of the co-stimulatory receptor CD226 together with its regulator EOMES in CD4 and CD8 CAR T cells, whereas the co-inhibitory and competing receptor TIGIT demonstrated reduced levels in several CAR T subsets as well as CD8 T central memory and Tscm cells. In line with the latter result, lower expression of the immune checkpoint CTLA-4 was detected in both CAR positive and negative unconventional T cells, indicating immunopathological signatures in CRS and ICANS are based on imbalanced activating/inhibitory receptor profiles.

Supportive for a pivotal role of the immune environment in CAR T treated patients, stratifying immune signatures associated with patient outcomes were already detected pre-CAR-T-infusion (Figure 2). Towards clinical translation, these altered signatures affecting the T, NK and myeloid/dendritic cell compartment are further investigated and could serve as potential biomarkers predicting patient outcome.

In-depth immune profiling of CAR T treated lymphoma patients allowed us to ultimately define the CAR T specific immune landscape and uncovered a synergy of CAR T and surrounding immune cells in stratifying immune profiles. These results could serve to delineate CAR T-based therapeutic strategies targeting the immunopathologic cascade, aimed to enhance anti-cancer activity and confine toxicity.


Disclosures: Alberti: Philogen S.p.A.: Current Employment. Zenz: Roche: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Incyte: Consultancy, Honoraria; Janpix: Consultancy, Honoraria. Manz: CDR-Life Inc: Consultancy, Current holder of stock options in a privately-held company; University of Zurich: Patents & Royalties: CD117xCD3 TEA. Müller: Novartis: Consultancy, Honoraria; Kite/Gilead: Consultancy, Honoraria; Celgene/BMS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Becher: Numab: Membership on an entity's Board of Directors or advisory committees.

*signifies non-member of ASH