scholarly journals CD19/BAFF-R Dual-Targeted CAR T Cells for the Treatment of Mixed Antigen-Negative Variants of Acute Lymphoblastic Leukemia

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2783-2783
Author(s):  
Xiuli Wang ◽  
Zhenyuan Dong ◽  
Wen-Chung Chang ◽  
Wesley Cheng ◽  
Vibhuti Vyas ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Dual Targeting ◽  
Car T Cell Therapy ◽  
Car T

Abstract The results of clinical trials evaluating CD19-targeting chimeric antigen receptor (CAR) T cells are impressive, with overall response rates of up to 90% in B cell acute lymphoblastic leukemia (ALL) and 50-80% in lymphoma. Despite initial responses, antigen-negative relapse is common following treatment with CD19-targeted therapies and is estimated to occur in up to 39% of patients. One approach of addressing this problem is to utilize dual-targeting CAR T cells, a strategy that has recently been applied to CD19/CD22 for ALL, CS1/BCMA, and BCMA/GPRC5D for multiple myeloma. Dual-targeting CARs can simultaneously target two tumor antigens and, therefore, potentially eradicate heterogeneous tumors. The initial response to dual-targeted CAR T cells is expected to provide greater tumor coverage compared to single-targeted therapy, and can potentially circumvent antigen escape. Moreover, if one tumor antigen becomes downregulated during treatment, the second targeting domain will continue to be reactive to tumors. Therefore, it is critical to identify novel targets that can be combined with CD19 in a dual-targeted immunotherapeutic platform. To expand the potential for dual targeting of ALL, we developed a CAR T cell therapy against a novel target, B-cell activating factor receptor (BAFF-R), based on the remarkable specificity of anti-BAFF-R antibodies that we previously generated. BAFF-R is expressed almost exclusively on B cells, including in patients with CD19-negative relapse, making it an ideal immunotherapeutic target. Studies demonstrate that the role of BAFF-R in B cell function and survival is conclusive, an important feature that may mitigate the tumor's ability to escape therapy through antigen loss, particularly if a non-redundant role for BAFF-R is confirmed. BAFF-R-CAR T cells demonstrate in vitro effector function and in vivo therapeutic efficacy in CD19-negative models, including patient-derived xenograft models, and are currently being evaluated clinically for the treatment of ALL (NCT04690595). We hypothesized that simultaneous targeting of CD19 and BAFF-R in a bispecific CAR platform could confer a therapeutic advantage and avoid the challenges of sequential administration of CD19 and BAFF-R monospecific CAR T cells. We leveraged our experience with CD19- and BAFF-R-CAR T cells to develop a dual-targeting, bispecific CAR with a 41BB costimulatory domain (CD19/BAFF-R dual CAR). Here, we identified the optimal orientation of the single-chain variable fragment (loop scFv) domains within the dual construct and tested the CD19/BAFF-R dual CAR T cells for their in vitro effector function and in vivo anti-leukemia activity. To evaluate the specific targeting to CD19 and BAFFR, we developed Nalm-6-BAFF-R-knockout (KO) and Nalm-6-CD19-KO cell lines. CD19/BAFF-R dual CAR T cells specifically released IFN-g following incubation with Nalm-6 CD19-/- or BAFF-R-/- cells (P<0.001) compared with un-transduced mock T cells. Both CD4+ and CD8+ CAR T cell populations exhibited effector function. To evaluate the antigen-dependent targeting of the CD19/BAFF-R dual CAR T cells in vivo, we utilized a mixed B-cell leukemia model that simulates clinical tumor heterogeneity. NOD-scid IL2Rgammanull (NSG) mice were inoculated with 2-3x10 5 of mixed Nalm-6 BAFF-R-/- and CD19-/- cells at a 1:1 ratio with a single injection. 1x10 6 CD19/BAFF-R dual CAR, CD19, or BAFF-R single CAR-T cells were administered intravenously 9-10 days later. Tumor growth was monitored by bioluminescent imaging weekly. We observed superior tumor eradication (P<0.01) and survival (P<0.01) (Figure 1) by CD19/BAFF-R dual CAR T cells compared to either single-targeting CAR and mock T cells. The adoptively transferred CD19/BAFF-R dual CAR T cells were able to persist in vivo. Our unique CD19/BAFF-R dual-targeting CAR T cells will be the first to target this combination of tumor-associated antigens. Our study demonstrated the reliability of bispecific CD19/BAFF-R dual CAR T cell therapy in inducing remission in ALL consisting of CD19-/- and BAFF-R-/- tumors. We hypothesize that simultaneous immunotherapy targeting of heterogeneous leukemic cell populations may diminish the likelihood of antigen escape and may have a significant impact on leukemia treatment by improving the therapeutic benefits of CAR T cell therapy. Figure 1 Figure 1. Disclosures Wang: Pepromene Bio, Inc.: Consultancy. Forman: Mustang Bio: Consultancy, Current holder of individual stocks in a privately-held company; Allogene: Consultancy; Lixte Biotechnology: Consultancy, Current holder of individual stocks in a privately-held company. Kwak: Pepromene Bio, Inc.: Consultancy, Current equity holder in publicly-traded company. Qin: Pepromene Bio, Inc.: Consultancy, Current equity holder in publicly-traded company.

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 124 Functionalizing CAR T cells for selective proliferation and dual-targeting using the meditope technology

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A133-A133
Author(s):  
Cheng-Fu Kuo ◽  
Yi-Chiu Kuo ◽  
Miso Park ◽  
Zhen Tong ◽  
Brenda Aguilar ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

BackgroundMeditope is a small cyclic peptide that was identified to bind to cetuximab within the Fab region. The meditope binding site can be grafted onto any Fab framework, creating a platform to uniquely and specifically target monoclonal antibodies. Here we demonstrate that the meditope binding site can be grafted onto chimeric antigen receptors (CARs) and utilized to regulate and extend CAR T cell function. We demonstrate that the platform can be used to overcome key barriers to CAR T cell therapy, including T cell exhaustion and antigen escape.MethodsMeditope-enabled CARs (meCARs) were generated by amino acid substitutions to create binding sites for meditope peptide (meP) within the Fab tumor targeting domain of the CAR. meCAR expression was validated by anti-Fc FITC or meP-Alexa 647 probes. In vitro and in vivo assays were performed and compared to standard scFv CAR T cells. For meCAR T cell proliferation and dual-targeting assays, the meditope peptide (meP) was conjugated to recombinant human IL15 fused to the CD215 sushi domain (meP-IL15:sushi) and anti-CD20 monoclonal antibody rituximab (meP-rituximab).ResultsWe generated meCAR T cells targeting HER2, CD19 and HER1/3 and demonstrate the selective specific binding of the meditope peptide along with potent meCAR T cell effector function. We next demonstrated the utility of a meP-IL15:sushi for enhancing meCAR T cell proliferation in vitro and in vivo. Proliferation and persistence of meCAR T cells was dose dependent, establishing the ability to regulate CAR T cell expansion using the meditope platform. We also demonstrate the ability to redirect meCAR T cells tumor killing using meP-antibody adaptors. As proof-of-concept, meHER2-CAR T cells were redirected to target CD20+ Raji tumors, establishing the potential of the meditope platform to alter the CAR specificity and overcome tumor heterogeneity.ConclusionsOur studies show the utility of the meCAR platform for overcoming key challenges for CAR T cell therapy by specifically regulating CAR T cell functionality. Specifically, the meP-IL15:sushi enhanced meCAR T cell persistence and proliferation following adoptive transfer in vivo and protects against T cell exhaustion. Further, meP-ritiuximab can redirect meCAR T cells to target CD20-tumors, showing the versatility of this platform to address the tumor antigen escape variants. Future studies are focused on conferring additional ‘add-on’ functionalities to meCAR T cells to potentiate the therapeutic effectiveness of CAR T cell therapy.

scholarly journals Targeting glycosylation of PD-1 to enhance CAR-T cell cytotoxicity

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaojuan Shi ◽  
Daiqun Zhang ◽  
Feng Li ◽  
Zhen Zhang ◽  
Shumin Wang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Inhibitory Effects ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

AbstractAsparagine-linked (N-linked) glycosylation is ubiquitous and can stabilize immune inhibitory PD-1 protein. Reducing N-linked glycosylation of PD-1 may decrease PD-1 expression and relieve its inhibitory effects on CAR-T cells. Considering that the codon of Asparagine is aac or aat, we wondered if the adenine base editor (ABE), which induces a·t to g·c conversion at specific site, could be used to reduce PD-1 suppression by changing the glycosylated residue in CAR-T cells. Our results showed ABE editing altered the coding sequence of N74 residue of PDCD1 and downregulated PD-1 expression in CAR-T cells. Further analysis showed ABE-edited CAR-T cells had enhanced cytotoxic functions in vitro and in vivo. Our study suggested that the single base editors can be used to augment CAR-T cell therapy.

scholarly journals GPRC5D is a target for the immunotherapy of multiple myeloma with rationally designed CAR T cells

2019 ◽  
Vol 11 (485) ◽  
pp. eaau7746 ◽  
Author(s):  
Eric L. Smith ◽  
Kim Harrington ◽  
Mette Staehr ◽  
Reed Masakayan ◽  
Jon Jones ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
B Cell ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell Therapy ◽  
Car T

Early clinical results of chimeric antigen receptor (CAR) T cell therapy targeting B cell maturation antigen (BCMA) for multiple myeloma (MM) appear promising, but relapses associated with residual low-to-negative BCMA-expressing MM cells have been reported, necessitating identification of additional targets. The orphan G protein–coupled receptor, class C group 5 member D (GPRC5D), normally expressed only in the hair follicle, was previously identified as expressed by mRNA in marrow aspirates from patients with MM, but confirmation of protein expression remained elusive. Using quantitative immunofluorescence, we determined that GPRC5D protein is expressed on CD138+ MM cells from primary marrow samples with a distribution that was similar to, but independent of, BCMA. Panning a human B cell–derived phage display library identified seven GPRC5D-specific single-chain variable fragments (scFvs). Incorporation of these into multiple CAR formats yielded 42 different constructs, which were screened for antigen-specific and antigen-independent (tonic) signaling using a Nur77-based reporter system. Nur77 reporter screen results were confirmed in vivo using a marrow-tropic MM xenograft in mice. CAR T cells incorporating GPRC5D-targeted scFv clone 109 eradicated MM and enabled long-term survival, including in a BCMA antigen escape model. GPRC5D(109) is specific for GPRC5D and resulted in MM cell line and primary MM cytotoxicity, cytokine release, and in vivo activity comparable to anti-BCMA CAR T cells. Murine and cynomolgus cross-reactive CAR T cells did not cause alopecia or other signs of GPRC5D-mediated toxicity in these species. Thus, GPRC5D(109) CAR T cell therapy shows potential for the treatment of advanced MM irrespective of previous BCMA-targeted therapy.

Presence of Endogenous TCR Antigen in Vivo Attenuates Efficacy of Anti-CD19 Targeted CAR T Cell Therapy

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3721-3721
Author(s):  
Yinmeng Yang ◽  
Christopher Daniel Chien ◽  
Elad Jacoby ◽  
Haiying Qin ◽  
Waleed Haso ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Ex Vivo ◽  
Ifn Gamma ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Abstract Adoptive therapy using T cells genetically engineered to express chimeric antigen receptors (CAR) has proven extremely effective against acute lymphoblastic leukemia (ALL) in clinical trials with the use of anti-CD19 CAR T cells. Most CAR T cell protocols use autologous T cells, which are then activated, transduced with the anti-CD19 CAR, and expanded ex-vivo before infusion back into the patient. This approach minimizes the risk of graft-versus-host disease (GVHD) even in allogeneic transplant recipients, due to tolerization of the donor T cell repertoire in the recipient. However, many patients have heavy disease burden and lymphopenia due to previous treatments, which makes the isolation of healthy T cells difficult. Thus, centers are exploring the potential of allogeneic T cell donors and the possibility of universal T cell donors for CAR-based therapy including the use of virus-specific T cells. In these cases, in addition to the chimeric receptor specificity, the transduced T cell population will also have reactivity against target antigens through the endogenous TCR. However, little is known about the impact of signaling of the endogenous TCR on CAR T cell activity, particularly in vivo. To test this, we used a syngeneic transplantable ALL murine model, E2aPBx, in which CD19 CAR T cells can effectively eradicate ALL. CD4 (Marilyn) and CD8 (Matahari) T cells from syngeneic HY-TCR transgenic donors specific for the minor histocompatibility male antigen, HY, were used as CAR T cell donors to control for endogenous TCR reactivity. Splenic T cells isolated from Matahari, Marilyn, or B6 mice were activated ex-vivo using anti-CD3/anti-CD28 beads, with the addition of IL2 and IL7. T cells were transduced with a retroviral vector expressing a murine CAR composed of anti-CD19 scfv/CD28/CD3ζ on days two and three. CAR T cells are evaluated in vitro by CD107a degranulation assay and INF gamma ELISA. In response to HY peptide alone or HY+CD19- line M39M, transduced CD8 HY (Matahari) cells produced IFN gamma and expressed CD107a whereas transduced CD4 HY (Marilyn) cells only produced IFN gamma. Interestingly, in response to CD19+HY- ALL, both Matahari and Marilyn expressed CD107a and produced IFN gamma indicating that CD4 T cells can acquire CD8-like lytic activity when stimulated through a CAR receptor. When CD19 CAR transduced Marilyns and Mataharis were stimulated in the presence of HY and CD19, CD8 Mataharis had an attenuated effect against CD19, suggesting that the presence of antigen activated TCR adversely affects the potency of the CAR receptor. Efficacy of the HY and polyclonal CAR T cells were next tested in-vivo in male and female B6 mice. Mice were given 1E6 E2aPBx ALL leukemia cells on day 1, and received 500 rads sub-lethal total body irradiation on day 4 as a lymphodepleting regimen. On day 5, mice were given a low (1E5) or high (5E6) dose of CAR T cells. There was a statistically significant (p=0.0177) improvement in the survival of female versus male mice after treatment with the CD4+ HY specific anti-CD19 CAR T cells, and female mice that received HY anti-CD19 CAR T cells survived longer than untreated control females (p=0.01). Remarkably, the survival of male mice that received HY anti-CD19 CAR T cells was statistically worse than untreated control males (p=0.008). This suggests that the presence of TCR antigen negatively impacts the function of CAR T cells. Furthermore, in a separate experiment using an equally mixed population of Marilyn (CD4+) and Matahari (CD8+) HY specific T cells, males has a statistically significantly (p=0.0116) worse survival compared to females after receiving 5E5 HY specific T cells. In conclusion, simultaneous stimulation through both CAR and TCR results in attenuated cytokine production and degranulation by CD8 T cells. In vivo, in the presence of the endogenous TCR antigen, both CD4 and CD8 CAR T cells are less potent at eradicating leukemia. These have implications for the development of universal donors for CAR T cell therapy. Disclosures No relevant conflicts of interest to declare.

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.

Quality Assessment of Pre-Clinical Studies of Chimeric Antigen Receptor T-Cell Therapy Products: A Point of Focus On Safety

2021 ◽  
Vol 16 ◽  
Author(s):  
Vikas Maharshi ◽  
Diksha Diksha ◽  
Pooja Gupta
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Chimeric Antigen Receptor ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Background: Serious adverse reactions have been reported with the use of chimeric antigen receptor (CAR) T-cell therapy in clinical setting despite the success of these products in pre-clinical stages of development. Objective: We evaluated the quality of available pre-clinical safety data of CAR T-cell therapy products. Methods: A 21 items safety-checklist was designed specifically for CAR T-cell. Literature was searched using search/MeSH terms in PubMed (October 2019 – February 2020). Studies were screened from title and abstract. Original pre-clinical researches related to CAR T-cell anti-cancer therapy were included. Results: Of the search results, 152 studies (3 in vivo, 39 in vitro, and 110 combined) were included. Only 7.9% studies were specifically designed to evaluate/ improve product safety. Eleven studies included target antigen(s) and no study included co-stimulatory molecule(s) expressed exclusively by tumor tissue and/or CAR T-cells. One study used CRISPR-Cas9 for CAR gene insertion. The use of switch-off mechanism and purity assessment of CAR T-cell products were reported in 13.2% and 8.6% studies respectively. Of the 149 studies with in vivo component, immuno-competent animal models were used in 24.8%. Measurement of blood pressure, temperature, body weight and serum cytokines were reported in 0, 2.7, 29.2 and 27.4% studies respectively. The tissue distribution and CAR T-cells persistence were reported in 26.5% studies. Conclusion: Majority of the checklist parameters were not reported in the pre-clinical publications to be adequately predictive of the safety of CAR T-cells in a clinical setting.

Sign in / Sign up

Export Citation Format

Share Document