scholarly journals CAR T-Cells for CNS Lymphoma: Driving into New Terrain?

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2503
Author(s):  
Philipp Karschnia ◽  
Jens Blobner ◽  
Nico Teske ◽  
Florian Schöberl ◽  
Esther Fitzinger ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cns Lymphoma ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T ◽  
Cns Lymphomas

Primary CNS lymphomas (PCNSL) represent a group of extranodal non-Hodgkin lymphoma and secondary CNS lymphomas refer to secondary involvement of the neuroaxis by systemic disease. CNS lymphomas are associated with limited prognosis even after aggressive multimodal therapy. Chimeric antigen receptor (CAR) T-cells have proven as a promising therapeutic avenue in hematological B-cell malignancies including diffuse large B-cell lymphoma, B-cell acute lymphoblastic leukemia, and mantle-cell lymphoma. CARs endow an autologous T-cell population with MHC-unrestricted effectivity against tumor target antigens such as the pan B-cell marker CD19. In PCNSL, compelling and long-lasting anti-tumor effects of such therapy have been shown in murine immunocompromised models. In clinical studies on CAR T-cells for CNS lymphoma, only limited data are available and often include both patients with PCNSL but also patients with secondary CNS lymphoma. Several clinical trials on CAR T-cell therapy for primary and secondary CNS lymphoma are currently ongoing. Extrapolated from the available preliminary data, an overall acceptable safety profile with considerable anti-tumor effects might be expected. Whether these beneficial anti-tumor effects are as long-lasting as in animal models is currently in doubt; and the immunosuppressive tumor microenvironment of the brain may be among the most pivotal factors limiting efficacy of CAR T-cell therapy in CNS lymphoma. Based on an increasing understanding of CAR T-cell interactions with the tumor cells as well as the cerebral tissue, modifications of CAR design or the combination of CAR T-cell therapy with other therapeutic approaches may aid to release the full therapeutic efficiency of CAR T-cells. CAR T-cells may therefore emerge as a novel treatment strategy in primary and secondary CNS lymphoma.

scholarly journals 221 CRISPR screen identifies loss of IFNγR signaling and downstream adhesion as a resistance mechanism to CAR T-cell cytotoxicity in solid but not liquid tumors

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A234-A234
Author(s):  
Rebecca Larson ◽  
Michael Kann ◽  
Stefanie Bailey ◽  
Nicholas Haradhvala ◽  
Kai Stewart ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Solid Tumors ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

BackgroundChimeric Antigen Receptor (CAR) therapy has had a transformative impact on the treatment of hematologic malignancies1–6 but success in solid tumors remains elusive. We hypothesized solid tumors have cell-intrinsic resistance mechanisms to CAR T-cell cytotoxicity.MethodsTo systematically identify resistance pathways, we conducted a genome-wide CRISPR knockout screen in glioblastoma cells, a disease where CAR T-cells have had limited efficacy.7 8 We utilized the glioblastoma cell line U87 and targeted endogenously expressed EGFR with CAR T-cells generated from 6 normal donors for the screen. We validated findings in vitro and in vivo across a variety of human tumors and CAR T-cell antigens.ResultsLoss of genes in the interferon gamma receptor (IFNγR) signaling pathway (IFNγR1, JAK1, JAK2) rendered U87 cells resistant to CAR T-cell killing in vitro. IFNγR1 knockout tumors also showed resistance to CAR T cell treatment in vivo in a second glioblastoma line U251 in an orthotopic model. This phenomenon was irrespective of CAR target as we also observed resistance with IL13Ralpha2 CAR T-cells. In addition, resistance to CAR T-cell cytotoxicity through loss of IFNγR1 applied more broadly to solid tumors as pancreatic cell lines targeted with either Mesothelin or EGFR CAR T-cells also showed resistance. However, loss of IFNγR signaling did not impact sensitivity of liquid tumor lines (leukemia, lymphoma or multiple myeloma) to CAR T-cells in vitro or in an orthotopic model of leukemia treated with CD19 CAR. We isolated the effects of decreased cytotoxicity of IFNγR1 knockout glioblastoma tumors to be cancer-cell intrinsic because CAR T-cells had no observable differences in proliferation, activation (CD69 and LFA-1), or degranulation (CD107a) when exposed to wildtype versus knockout tumors. Using transcriptional profiling, we determined that glioblastoma cells lacking IFNγR1 had lower upregulation of cell adhesion pathways compared to wildtype glioblastoma cells after exposure to CAR T-cells. We found that loss of IFNγR1 reduced CAR T-cell binding avidity to glioblastoma.ConclusionsThe critical role of IFNγR signaling for susceptibility of solid tumors to CAR T-cells is surprising given that CAR T-cells do not require traditional antigen-presentation pathways. Instead, in glioblastoma tumors, IFNγR signaling was required for sufficient adhesion of CAR T-cells to mediate productive cytotoxicity. Our work demonstrates that liquid and solid tumors differ in their interactions with CAR T-cells and suggests that enhancing T-cell/tumor interactions may yield improved responses in solid tumors.AcknowledgementsRCL was supported by T32 GM007306, T32 AI007529, and the Richard N. Cross Fund. ML was supported by T32 2T32CA071345-21A1. SRB was supported by T32CA009216-38. NJH was supported by the Landry Cancer Biology Fellowship. JJ is supported by a NIH F31 fellowship (1F31-MH117886). GG was partially funded by the Paul C. Zamecnik Chair in Oncology at the Massachusetts General Hospital Cancer Center and NIH R01CA 252940. MVM and this work is supported by the Damon Runyon Cancer Research Foundation, Stand Up to Cancer, NIH R01CA 252940, R01CA238268, and R01CA249062.ReferencesMaude SL, et al. Tisagenlecleucel in children and young adults with B-cell lymphoblastic leukemia. N Engl J Med 2018;378:439–448.Neelapu SS, et al. Axicabtagene ciloleucel CAR T-cell therapy in refractory large B-cell lymphoma. N Engl J Med 2017;377:2531–2544.Locke FL, et al. Long-term safety and activity of axicabtagene ciloleucel in refractory large B-cell lymphoma (ZUMA-1): a single-arm, multicentre, phase 1–2 trial. The Lancet Oncology 2019;20:31–42.Schuster SJ, et al. Chimeric antigen receptor T cells in refractory B-cell lymphomas. N Engl J Med 2017;377:2545–2554.Wang M, et al. KTE-X19 CAR T-cell therapy in relapsed or refractory mantle-cell lymphoma. N Engl J Med 2020;382:1331–1342.Cohen AD, et al. B cell maturation antigen-specific CAR T cells are clinically active in multiple myeloma. J Clin Invest 2019;129:2210–2221.Bagley SJ, et al. CAR T-cell therapy for glioblastoma: recent clinical advances and future challenges. Neuro-oncology 2018;20:1429–1438.Choi BD, et al. Engineering chimeric antigen receptor T cells to treat glioblastoma. J Target Ther Cancer 2017;6:22–25.Ethics ApprovalAll human samples were obtained with informed consent and following institutional guidelines under protocols approved by the Institutional Review Boards (IRBs) at the Massachusetts General Hospital (2016P001219). Animal work was performed according to protocols approved by the Institutional Animal Care and Use Committee (IACUC) (2015N000218 and 2020N000114).

scholarly journals Iomab with Adoptive Cellular Therapy (Iomab-ACT): A Pilot Study of 131-I Apamistamab Followed By CD19-Targeted CAR T-Cell Therapy for Patients with Relapsed or Refractory B-Cell Acute Lymphoblastic Leukemia or Diffuse Large B-Cell Lymphoma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4810-4810
Author(s):  
Mark B. Geyer ◽  
Briana Cadzin ◽  
Elizabeth Halton ◽  
Peter Kane ◽  
Brigitte Senechal ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
B Cell ◽  
Research Funding ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Abstract Background: Autologous CD19-targeted chimeric antigen receptor-modified (CAR) T-cell therapy leads to complete responses (CR) in patients (pts) with (w/) relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL, >80% CR rate) and diffuse large B-cell lymphoma (DLBCL, ~40-55% CR rate). However, following fludarabine/cyclophosphamide (Flu/Cy) conditioning and CAR T-cell therapy w/ a CD28 costimulatory domain (e.g. 19-28z CAR T-cells), rates of grade ≥3 ICANS and grade ≥3 cytokine release syndrome (CRS) in pts w/ R/R DLBCL and morphologic R/R B-ALL exceed 30%. CRS and ICANS are associated w/ considerable morbidity, including increased length of hospitalization, and may be fatal. Host monocytes appear to be the major reservoir of cytokines driving CRS and ICANS post-CAR T-cell therapy (Giavradis et al. and Norelli et al., Nature Medicine, 2018). Circulating monocytic myeloid-derived suppressor cells (MDSCs) may also blunt efficacy of 19-28z CAR T-cells in R/R DLBCL (Jain et al., Blood, 2021). The CD45-targeted antibody radioconjugate (ARC) 131-I apamistamab is being investigated at myeloablative doses as conditioning prior to hematopoietic cell transplantation in pts w/ R/R acute myeloid leukemia. However, even at low doses (4-20 mCi), transient lymphocyte and blast reduction are observed. Preclinical studies in C57BL/6 mice demonstrate low-dose anti CD45 radioimmunotherapy (100 microCi) transiently depletes >90% lymphocytes, including CD4/CD8 T-cells, B-cells, NK cells, and T-regs, as well as splenocytes and MDSCs, w/ negligible effect on bone marrow (BM) hematopoietic stem cells (Dawicki et al., Oncotarget, 2020). We hypothesized a higher, yet nonmyeloablative dose of 131-I apamistamab may achieve more sustained, but reversible depletion of lymphocytes and other CD45 + immune cells, including monocytes thought to drive CRS/ICANS. We additionally hypothesized this approach (vs Flu/Cy) prior to CAR T-cell therapy would promote CAR T-cell expansion while reducing CSF levels of monocyte-derived cytokines (e.g. IL-1, IL-6, and IL-10), thus lowering the risk of severe ICANS (Fig 1A). Study design and methods: We are conducting a single-institution pilot study of 131-I apamistamab in lieu of Flu/Cy prior to 19-28z CAR T-cells in adults w/ R/R BALL or DLBCL (NCT04512716; Iomab-ACT); accrual is ongoing. Pts are eligible for leukapheresis if they are ≥18 years-old w/ R/R DLBCL (de novo or transformed) following ≥2 chemoimmunotherapy regimens w/ ≥1 FDG-avid measurable lesion or B-ALL following ≥1 line of multi-agent chemotherapy (R/R following induction/consolidation; prior 2 nd/3 rd gen TKI required for pts w/ Ph+ ALL) w/ ≥5% BM involvement and/or FDG-avid extramedullary disease, ECOG performance status 0-2, and w/ appropriate organ function. Active or prior CNS disease is not exclusionary. Pts previously treated w/ CD19-targeted CAR T-cell therapy are eligible as long as CD19 expression is retained. See Fig 1B/C: Post-leukapheresis, 19-28z CAR T-cells are manufactured as previously described (Park et al., NEJM, 2018). Bridging therapy is permitted at investigator discretion. Thyroid blocking is started ≥48h pre-ARC. 131-I apamistamab 75 mCi is administered 5-7 days pre-CAR T-cell infusion to achieve total absorbed marrow dose ~200 cGy w/ remaining absorbed dose <25 cGy at time of T-cell infusion. 19-28z CAR T-cells are administered as a single infusion (1x10 6/kg, B-ALL pts; 2x10 6/kg, DLBCL pts). The primary objective is to determine safety/tolerability of 131-I apamistamab 75 mCi given prior to 19-28z CAR T-cells in pts w/ R/R B-ALL/DLBCL. Secondary objectives include determining incidence/severity of ICANS and CRS, anti-tumor efficacy, and 19-28z CAR T-cell expansion/persistence. Key exploratory objectives include describing the cellular microenvironment following ARC and 19-28z CAR T-cell infusion using spectral cytometry, as well as cytokine levels in peripheral blood and CRS. The trial utilizes a 3+3 design in a single cohort. If dose-limiting toxicity (severe infusion-related reactions, treatment-resistant severe CRS/ICANS, persistent regimen-related cytopenias, among others defined in protocol) is seen in 0-1 of the first 3 pts treated, then up to 6 total (up to 3 additional) pts will be treated. We have designed this study to provide preliminary data to support further investigation of CD45-targeted ARCs prior to adoptive cellular therapy. Figure 1 Figure 1. Disclosures Geyer: Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Actinium Pharmaceuticals, Inc: Research Funding; Amgen: Research Funding. Geoghegan: Actinium Pharmaceuticals, Inc: Current Employment. Reddy: Actinium Pharmaceuticals: Current Employment, Current holder of stock options in a privately-held company. Berger: Actinium Pharmaceuticals, Inc: Current Employment. Ludwig: Actinium Pharmaceuticals, Inc: Current Employment. Pandit-Taskar: Bristol Myers Squibb: Research Funding; Bayer: Research Funding; Clarity Pharma: Research Funding; Illumina: Consultancy, Honoraria; ImaginAb: Consultancy, Honoraria, Research Funding; Ymabs: Research Funding; Progenics: Consultancy, Honoraria; Medimmune/Astrazeneca: Consultancy, Honoraria; Actinium Pharmaceuticals, Inc: Consultancy, Honoraria; Janssen: Research Funding; Regeneron: Research Funding. Sauter: Genmab: Consultancy; Celgene: Consultancy, Research Funding; Precision Biosciences: Consultancy; Kite/Gilead: Consultancy; Bristol-Myers Squibb: Research Funding; GSK: Consultancy; Gamida Cell: Consultancy; Novartis: Consultancy; Spectrum Pharmaceuticals: Consultancy; Juno Therapeutics: Consultancy, Research Funding; Sanofi-Genzyme: Consultancy, Research Funding. OffLabel Disclosure: 131-I apamistamab and 19-28z CAR T-cells are investigational agents in treatment of ALL and DLBCL

scholarly journals CD229 CAR T Cell Therapy for the Treatment of Relapsed B Cell Lymphoma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2800-2800
Author(s):  
Michael Olson ◽  
Tim Luetkens ◽  
Fiorella Iglesias ◽  
Sabarinath Radhakrishnan ◽  
Jennie Y. Law ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Abstract B cell lymphoma is the most common hematologic malignancy in the United States. Although treatment options have greatly improved in the past several decades, outcomes for patients with relapsed B cell lymphoma remain poor. Chimeric antigen receptor (CAR) T cells have recently entered the clinic with promise to address the gap in effective therapies for patients relapsed B cell lymphoma. However, antigen loss and poor CAR T cell persistence has been shown to drive resistance to the widely approved CD19-targeted CAR in some patients, demonstrating the need for additional therapies. Here, we demonstrate CD229-targeted CAR T cell therapy as a promising option for the treatment of relapsed B cell lymphoma, addressing an important group of patients with typically poor outcomes. CD229 is an immune-modulating receptor expressed on the surface of B cells that we recently found to be highly expressed in the plasma cell neoplasm multiple myeloma (Radhakrishnan et al. 2020). We utilized semi-quantitative PCR and flow cytometry to assess whether CD229 is also expressed on malignant B cells earlier in development as found in B cell lymphoma. Expression analysis revealed the presence of CD229 in a panel of 11 B cell lymphoma cell lines and 45 primary B cell lymphoma samples comprising several subsets of disease including aggressive B cell lymphomas such as diffuse large B cell lymphoma (DLBCL), mantle cell lymphoma (MCL) and Burkitt lymphoma as well as indolent subtypes of B cell lymphoma including chronic lymphoblastic leukemia (CLL) and follicular lymphoma. Of note, CD229 was found to be overexpressed on primary B cell lymphoma cells when compared to autologous normal B cells. Given the high levels of CD229 expression throughout all B cell lymphoma subtypes analyzed, we generated CD229 CAR T cells in order to determine whether CAR T cell therapy is an effective way to target CD229 expressing B cell lymphoma cells. CD229 CAR T cells exhibited robust cytotoxicity when cocultured with B cell lymphoma cell lines and primary samples characterized by significant production of TH1 cytokines IL-2, TNF and IFNγ and rapid loss of B cell lymphoma cell viability when compared to control CAR T cells lacking an antigen binding scFv domain (∆scFv CAR T cells). In vivo analysis revealed effective tumor control in NSG mice carrying B cell lymphoma cell lines JeKo-1 (MCL) and DB (DLBCL) when treated with CD229 CAR T cells versus ∆scFv CAR T cells. Finally, we sought to determine the efficacy of CD229 CAR T cells in the context of CD19 CAR T cell therapy relapse. Here, a 71-year-old patient with CLL had an initial response when treated with CD19 CAR T cells but quickly relapsed only 2 months after treatment. Malignant cells from the CLL patient retained CD229 expression as identified by flow cytometry and an ex vivo coculture with CD229 CAR T cells revealed robust killing of CLL cells by CD229 CAR T cells. Transfer of antigen from target cell to CAR T cell by trogocytosis was recently suggested to drive relapse following CAR T cell therapy by decreasing antigen on tumor cells and promoting CAR T cell fratricide (Hamieh et al. 2019). We cocultured CD19 and CD229 CAR T cells with primary CLL cells and assessed CD19 and CD229 expression as well as CAR T cell viability by flow cytometry. In contrast with CD19 CAR T cells, CD229 CARs did not strip their target antigen from the surface of CLL cells. The transfer of CD19 from CLL cells to CD19 CAR T cells resulted in poor CAR T cell viability while CD229 CAR T cell viability remained high following coculture. In summary, we demonstrate that CD229 is a promising therapeutic target in B cell lymphoma due to its high levels of expression throughout many subtypes of disease. CD229 CAR T cells effectively kill B cell lymphoma cells in vitro and control growth of aggressive B cell lymphomas in vivo. Finally, CD229 CAR T cells are effective against primary CLL cells from patients that have relapsed from CD19 CAR T cell therapy and do no exhibit antigen loss by trogocytosis. Taken together, these data suggest that CD229 CAR T cell therapy may be a promising option to address the poor outcomes for patients with relapsed B cell lymphoma. Disclosures No relevant conflicts of interest to declare.

scholarly journals Case Report: Sirolimus Alleviates Persistent Cytopenia After CD19 CAR-T-Cell Therapy

2021 ◽  
Vol 11 ◽  
Author(s):  
Limin Xing ◽  
Yihao Wang ◽  
Hui Liu ◽  
Shan Gao ◽  
Qing Shao ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
B Cell ◽  
B Cell Lymphoma ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Chimeric antigen receptor T (CAR-T) cells show good efficacy in the treatment of relapsed and refractory B-cell tumors, such as acute B-cell leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL). The main toxicities of CAR-T include cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, cytopenia, and severe infection. It is still very difficult for CAR-T to kill tumor cells to the maximum extent and avoid damaging normal organs. Here, we report a case of DLBCL with persistent grade 4 thrombocytopenia and severe platelet transfusion dependence treated with CD19 CAR-T cells. We used sirolimus to inhibit the sustained activation of CAR-T cells and restore normal bone marrow hematopoiesis and peripheral blood cells. Moreover, sirolimus treatment did not affect the short-term efficacy of CAR-T cells, and DLBCL was in complete remission at the end of follow-up. In conclusion, sirolimus can represent a new strategy for the management of CAR-T cell therapy-related toxicity, including but not limited to hematotoxicity. However, further controlled clinical studies are required to confirm these findings.

scholarly journals Antitumor efficacy of BAFF-R targeting CAR T cells manufactured under clinic-ready conditions

2020 ◽  
Vol 69 (10) ◽  
pp. 2139-2145
Author(s):  
Zhenyuan Dong ◽  
Wesley A. Cheng ◽  
D. Lynne Smith ◽  
Brian Huang ◽  
Tiantian Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
B Cell ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T ◽  
Antigen Loss

Abstract B-cell malignancies can potentially be cured by CD19 chimeric antigen receptor (CAR) T-cell therapy. Although clinical response rates can be up to 93% in acute lymphoblastic leukemia, treatment-related antigen loss and lack of therapeutic persistence contribute to disease relapse. These shortcomings of current CAR T-cell therapy indicate the need for biologically relevant target selection and for improving the efficacy and persistence of the CAR T cells, which we have addressed by developing a novel B-cell activating factor receptor (BAFF-R) CAR T-cell therapy with improved therapeutic persistence. BAFF-R is a B-cell survival receptor and highly expressed in B-cell malignancies. We developed a prototype CAR T cell that efficiently and specifically eliminated BAFF-R expressing human B-cell tumors in several xenogeneic mouse models, including models of CD19 antigen loss. We proceeded with translational development and validation of BAFF-R CAR T cells produced under current good manufacturing practices (cGMP). cGMP-grade BAFF-R CAR T cells underwent in vitro and in vivo validation in established models to confirm that the potency and efficacy of our original research modeling was replicated. Food and Drug Administration required release testing was performed to ensure our BAFF-R CAR T cells meet specifications for new drug products. Completing and exceeding these requirements, the data fully support the initiation of a first-in-human Phase 1 trial for BAFF-R-positive relapsed/refractory (r/r) B-ALL.

scholarly journals Novel BAFF-R CAR T-Cell Therapy for CD19 Antigen-Loss Relapsed B Cell Tumors

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1411-1411
Author(s):  
Hong Qin ◽  
Zhenyuan Dong ◽  
Xiuli Wang ◽  
Wesley Cheng ◽  
Diane Lynne Smith ◽  
...  
Keyword(s):  
T Cells ◽  
Targeted Therapy ◽  
T Cell ◽  
B Cell ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T ◽  
Antigen Loss

Abstract Background: Chimeric antigen receptor (CAR) T cells against CD19 have shown great potential in treatment of B cell malignancies. However, tumor relapse from antigen loss can limit efficacy. B-cell activating factor-receptor (BAFF-R), a tumor necrosis factor receptor superfamily protein (TNFRSF13C), is another potential B-cell specific target of B cell malignancies. BAFF-R is an especially interesting alternative to CD19 as BAFF-R signaling is a driver of B-cell survival, which may limit the capacity of clonal B-cell tumors to escape therapy by down-regulation of antigen expression. However, while the BAFF/BAFF-R axis has been successfully targeted for autoimmune diseases, the promise for cancer therapy has not yet been fulfilled. Methods and Results: A humanized, single-chain variable fragment (scFv) derivative of an anti-human BAFF-R antibody (Qin et al. Clin Can Res 2018;24:1114-1123) was engineered onto a second generation CAR construct containing 4-1BB costimulatory and CD3ζ intracellular signaling domains. BAFF-R-CAR T cells demonstrated cytotoxicity against human lymphoma and acute lymphocytic leukemia (ALL) lines. Adoptively transferred BAFF-R-CAR T cells eradicated 10-day pre-established tumor xenografts after a single treatment and were superior to CD19-CAR T cells (not shown) and retained efficacy against xenografts deficient in CD19 expression, including one primary patient-derived xenograft (PDX). Specifically, we modeled disease relapse due to the loss of CD19 by generating CRISPR CD19 gene knock-out of the ALL (Nalm-6) cell line and a gRNA-silenced CD19 gene knock-down of an ALL PDX. We confirmed the absence of CD19 and presence BAFF-R expression, which was unaffected, on the resulting cell lines by surface staining (Fig. 1A). Using transduced CD8 TN cells, we found that CD19-CAR T cells demonstrated cytotoxicity only against wild-type tumor cells, while BAFF-R-CAR T cells maintained significant cytotoxicity against both wild-type and CD19-negative tumors in vitro (Fig. 1B). The therapeutic efficacy of BAFF-R-CAR T cells was tested against human ALL Nalm-6-CD19 deficient xenografts established in NSG mice following IV tumor challenge on day 0 with luciferase-expressing cells. A single dose of 2.5 x 106 CD4 TN + 106 CD8 TN BAFF-R- or CD19-CAR T cells/mouse infused IV on day 11 post tumor implantation completely eliminated established Nalm-6-CD19KO ALL tumors and conferred long-term survival. In contrast, treatment with PBS or identical mixtures of CD19-CAR T cells or non-transduced T cells from the same donor were associated with progressive tumor growth and 100% mortality by Day 60 (Fig. 1C). Finally, four relapsed, antigen loss primary ALLs obtained after CD19-directed therapy retained BAFF-R expression and activated BAFF-R-, but not CD19-CAR T cells. Specifically, cell surface staining demonstrated CD19 and BAFF-R expression in tumors obtained prior to CD19-targeted therapy. However, post-treatment samples exhibited clear down-regulation of CD19, while retaining positive BAFF-R expression (Fig. 1D, results from a single representative patient shown). The ability of the primary tumor samples to activate either CD19- or BAFF-R-CAR T cells was determined by expression of the degranulation marker CD107a on the CAR T cells. Cryopreserved ALL samples were co-cultured with BAFF-R or CD19 CAR-T cells derived from the same healthy donor in the presence of anti-CD107a antibody for 6 h. Non-transduced T cells (non-CAR) from the same donor were used as a negative control. Activation of CD19-CAR T cells by all four CD19-negative post-blinatumomab therapy tumors was significantly reduced, compared with BAFF-R-CAR T cells and with corresponding available CD19-positive pre-therapy tumors, while BAFF-R-CAR T cells were equally activated by pre- and post-CD19-targeted therapy tumors (Fig.1E-F). We observed similar trends for both CD19- and BAFF-R-CAR T cell activation by pre- and post-CD19-targeted therapy tumors, as measured by specific intracellular CAR T-cell TNF-α and IFN-γ production (not shown). Conclusion: Taken together, our data suggest that BAFF-R is amenable to CAR T-cell therapy and that targeting it may add to existing alternative strategies to overcome relapse from CD19 antigen loss, such as CD22 CAR T cells. Future strategies combining dual targeting of CD19 and BAFF-R may also be effective. Disclosures Wang: Mustang Therapeutics: Other: Licensing Agreement, Patents & Royalties, Research Funding. Forman:Mustang Therapeutics: Other: Licensing Agreement, Patents & Royalties, Research Funding.

scholarly journals Systematically optimized BCMA/CS1 bispecific CAR-T cells robustly control heterogeneous multiple myeloma

2020 ◽  
Author(s):  
Eugenia Zah ◽  
Eunwoo Nam ◽  
Vinya Bhuvan ◽  
Uyen Tran ◽  
Brenda Y. Ji ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
B Cell ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

ABSTRACTChimeric antigen receptor (CAR)-T cell therapy has shown remarkable clinical efficacy against B-cell malignancies but also demonstrated marked vulnerability to antigen escape and tumor relapse. Here, we report the rational design and systematic optimization of bispecific CAR-T cells with robust activity against multiple myeloma (MM), including heterogeneous MM that is resistant to conventional CAR-T cell therapy targeting B-cell maturation antigen (BCMA). We demonstrate that BCMA/CS1 bispecific CAR-T cells exhibit significantly higher CAR expression levels and greater antigen-stimulated proliferation compared to T cells that co-express individual BCMA and CS1 CARs. Compared to single-input BCMA- or CS1-targeting CAR-T cells, BCMA/CS1 bispecific CAR-T cells significantly prolong the survival of animals bearing heterogeneous MM tumors. Combination therapy with anti–PD-1 antibody further accelerates the rate of initial tumor clearance in vivo, but CAR-T cell treatment alone was able to achieve durable tumor-free survival even upon tumor re-challenge. Taken together, the BCMA/CS1 bispecific CAR presents a promising treatment approach to prevent antigen escape in CAR-T cell therapy against MM, and the vertically integrated optimization process can be used to develop robust cell-based therapy against novel disease targets.

scholarly journals P02.01 Predictive impact of the gut microbiota on treatment response to CD19 specific CAR T-cells

2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A20.1-A20
Author(s):  
V Blumenberg ◽  
E Zamir ◽  
S Schmidt ◽  
R Gaiser ◽  
N Cullin ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Gut Microbiota ◽  
B Cell ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

BackgroundHigh response rates (RR) have led to the approval of the CD19 specific CAR T-cell products Axicabtagene-Ciloleucel and Tisagenlecleucel for the treatment of refractory/relapsed B-cell precursor ALL (BCP-ALL) and Diffuse Large B-cell lymphoma (DLBCL). However, only a subgroup of patients achieves long-term remission. Additionally, most patients experience adverse effects such as cytokine release syndrome or neurotoxicity. Therefore, we need to better understand mechanisms of relapse and disease progression or toxicity to improve effectiveness of CD19 CAR T-cell therapy. As the gut microbiota plays an important role in modulating T-cell based immunotherapy, we hypothesize, that its signature also impacts clinical outcomes of CAR T-cell therapy.Materials and MethodsWe are currently collecting and 16S rRNA sequencing fecal biospecimen from BCP-ALL and DLBCL patients before, during and after treatment with Axicabtagene-Ciloleucel and Tisagenlecleucel at the University Hospital of the LMU. Microbiota data are integrated into a patient-centered ‘hospitalome’ including onset and type of infection and of immunotoxicity, concomitant anti-infective and immunosuppressive agents as well as response to CAR T-cell therapy.ResultsPreliminary data analysis revealed, that 4–14 days after CAR T-cell infusion the alpha diversity of the gut microbiome of each patient decreases drastically, whereas pre-lymphodepletion gut microbiota has a high diversity. Furthermore, the microbiota composition during the course of treatment changes as seen by beta diversity changes. In more detail, after CAR T-cell infusion, we observed instances of gut microbiota mono-domination with Enterococci or the genus Rikinella.ConclusionsThe gut microbiome of patients being treated with CAR T cells undergoes large and diverse compositional changes. We currently explore how this microbiome heterogeneity relates to the distinct responses and immunotoxicity of patients after CAR T-cell therapy. Hence, this study will enable microbiome-based stratification of patients, in order to predict and improve patient outcome to this personalized T-cell recruiting immunotherapy approach.Disclosure InformationV. Blumenberg: None. E. Zamir: None. S. Schmidt: None. R. Gaiser: None. N. Cullin: None. V. Bücklein: None. C. Schmidt: None. M. von Bergwelt: None. E. Elinav: None. C.K. Stein-Thoeringer: None. M. Subklewe: None.

scholarly journals Befriending the Hostile Tumor Microenvironment in CAR T-Cell Therapy

2021 ◽  
Vol 11 ◽  
Author(s):  
Lorenzo Lindo ◽  
Lauren Hanna Wilkinson ◽  
Kevin Anthony Hay
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cell Function ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Local Immunosuppression ◽  
Car T

T-cells genetically engineered to express a chimeric antigen receptor (CAR) have shown remarkable results in patients with B-cell malignancies, including B-cell acute lymphoblastic leukemia, diffuse large B-cell lymphoma, and mantle cell lymphoma, with some promising efficacy in patients with multiple myeloma. However, the efficacy of CAR T-cell therapy is still hampered by local immunosuppression and significant toxicities, notably cytokine release syndrome (CRS) and neurotoxicity. The tumor microenvironment (TME) has been identified to play a major role in preventing durable responses to immunotherapy in both solid and hematologic malignancies, with this role exaggerated in solid tumors. The TME comprises a diverse set of components, including a heterogeneous population of various cells and acellular elements that collectively contribute towards the interplay of pro-immune and immunosuppressive signaling. In particular, macrophages, myeloid-derived suppressor cells, regulatory T-cells, and cell-free factors such as cytokines are major contributors to local immunosuppression in the TME of patients treated with CAR T-cells. In order to create a more favorable niche for CAR T-cell function, armored CAR T-cells and other combinatorial approaches are being explored for potential improved outcomes compared to conventional CAR T-cell products. While these strategies may potentiate CAR T-cell function and efficacy, they may paradoxically increase the risk of adverse events due to increased pro-inflammatory signaling. Herein, we discuss the mechanisms by which the TME antagonizes CAR T-cells and how innovative immunotherapy strategies are being developed to address this roadblock. Furthermore, we offer perspective on how these novel approaches may affect the risk of adverse events, in order to identify ways to overcome these barriers and expand the clinical benefits of this treatment modality in patients with diverse cancers. Precise immunomodulation to allow for improved tumor control while simultaneously mitigating the toxicities seen with current generation CAR T-cells is integral for the future application of more effective CAR T-cells against other malignancies.

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