scholarly journals CD19/CD22 Dual-Targeted Chimeric Antigen Receptor T-Cell Therapy for Relapsed/Refractory Aggressive B-Cell Lymphoma: a Safety and Efficacy Study

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 34-34
Author(s):  
Yongxian Hu ◽  
Yanlei Zhang ◽  
Houli Zhao ◽  
Yiyun Wang ◽  
Arnon Nagler ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Target Cells ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T ◽  
Aggressive B Cell Lymphoma

Introduction Chimeric antigen receptor (CAR)-T-cell therapy has revolutionized the treatment of relapsed/refractory (R/R) B-cell hematological malignancies, primarily acute lymphoblastic leukemia (ALL), and B-cell non-Hodgkin lymphoma (NHL). CD19 CAR-T cells have been extensively studied and have been shown to yield complete remission (CR) rates of about 90% in R/R ALL, but substantially lower (50%) rates in R/R NHL. Moreover, persistence is usually limited, and antigen escape-mediated relapse is a major limitation. Dual CAR-T cells targeting both CD19 and CD22 may address these limitations. Patients and methods We developed a bispecific CAR-T cells that could concomitantly recognize CD19- and CD22-expressing targets by incorporating both CD19 and CD22 single-chain variables in a single CAR construct (Figure 1A). We designed a prospective study to assess the safety and efficacy profiles of the dual CAR-T therapy in patients with R/R aggressive B-cell lymphoma. Results The preclinical cytotoxicity evaluation of the CD19/CD22 dual-targeted CAR-T cells was performed in comparison with mono-specific CD19-BB-002 and CD22-BB-002 CAR-T cells in HeLa cells that were engineered to express CD19, CD22, or both antigens. The dual-antigen specific CAR-T cells performed equally well when compared with the mono-specific CAR-T cells when there was only a single antigen present on the target cells; better performance was observed when both antigens were present on target cells (Figure 1B). In addition, the dual-antigen specific CAR-T cells induced equal amounts of interleukin (IL)-3, granulocyte-macrophage colony-stimulating factor (GM-CSF), and interferon (IFN)-γ, when compared with the two mono-specific CAR-T cells (Figure 1C). Furthermore, the CD19 CAR-T cells induced more IL-2 and tumor necrosis factor (TNF)-α than the CD22 CAR-T cells and dual-antigen CAR-T cells. However, in the presence of both CD19 and CD22 antigens, the dual-specific CAR-T cell tended to produce more granzyme B, which may explain the higher degree of cytotoxicity when compared with the two mono-specific CAR-T cells (Figure 1D). Twenty-four patients were screened. Of the 16 eligible patients 14 (87.5%) achieved objective response (RR), with 10 (62.5%) achieving complete response (CR). The 2-year overall survival (OS) and progression-free survival (PFS) rates were 77.3% and 40.2%, respectively (Figure 2A). Achieving CR (HR: 0.017, 95% CI: 0.000-0.935; P=0.046) and number of prior lines of chemotherapy (n=2) (HR:135.784, 95% CI: 1.069-17248.110, P=0.047) were found as independent prognostic factors associated with favorable PFS. The 2-year OS and PFS of the CR patients were higher than those of the non-CR patients (100% versus 41.7%, P=0.015; 66.7% versus 0%, P < 0.001), respectively (Figure 2B). The 2-year PFS in patients received 2 prior lines of chemotherapy was higher as compared to those that received more than 2 lines of chemotherapy (68.6% versus 16.7%, P=0.049) whereas the OS in the 2 groups did not differ significantly (83.3% and 71.1%, P=0.613) (Figure 2C). Severe grade 3 cytokine release syndrome (CRS) was observed in only one patient, while 4 had grade one and 11 had grade 2, respectively. No patient developed neurotoxicity. Conclusions Immunotherapy with a novel CD19/CD22 dual targeted CAR-T cells yields a potent and durable anti-lymphoma response with no neurotoxicity or severe CRS. Bispecific CD19/CD22 CAR-T cells represent a safe and potent anti-lymphoma cellular based targeted immunotherapy. Figure 1 Disclosures No relevant conflicts of interest to declare.

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 Sequential Infusion of Anti-CD22 and Anti-CD19 Chimeric Antigen Receptor T Cells Following Autologous HSCT in Patients with B-NHL

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2054-2054 ◽  
Author(s):  
Yang Cao ◽  
Na Wang ◽  
Gaoxiang Wang ◽  
Yi Xiao ◽  
Liang Huang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
High Risk ◽  
B Cell ◽  
Cell Lymphoma ◽  
Remission Rate ◽  
B Cell Lymphoma ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T

Abstract Salvage chemotherapy followed by autologous hematopoietic stem cell transplantation (HSCT) is the standard treatment for the patients with chemotherapy sensitive relapsed or refractory B-NHL. However, more than half of patients will ultimately relapse. To improve long-term remission rate, we administered adoptive T-cell immunotherapy after HSCT. Based on the findings that CD19/CD22 dual antigen targeting have been demonstrated to be a promising approach for overcoming antigen escape relapse, we conducted an open-label, single-center and single-arm pilot study of sequential infusion of anti-CD22 and anti-CD19 CAR-T cells following autologous HSCT. We aimed to evaluate its safety and efficacy in patients with relapsed, refractory and high-risk B cell lymphoma. This trial is registered with ChiCTR, number ChiCTR-OPN-16009847. Between December 2016 and March 2018, 20 patients were enrolled in this clinical trial, with a median age of 33 years (range, 24-61 years). Of these 20 treated patients, 2 had PMBCL, 4 had tFL,14 had DLBCL, 70.0% (14/20) had received at least three previous therapies. 50.0% patients (8/16) harbor a TP53 mutation. At baseline assessment (prior to conditioning), 3 participants had a CR, 8 had a PR, 8 had a PD, 1 had a SD. All patients received bis-chloroethyl nitrosourea, etoposide, Ara-C, and melphalan, CD22 and CD19 CAR T cells were infused 2 to 7 days after stem cell infusion. The median anti-CD22 and anti-CD19 CAR-T cells dose per kilogram of body weight were 4.0× 106 (range, 1.0-10.0×106) and 4.2× 106 (range, 1.8-10.0×106) respectively. Normal HSCT-associated neutrophil engraftment within 20 days in all 20 patients was observed. 11/20 (50.5%) patients experienced cytokine release syndrome and no patient had severe CRS (grade 3-4). Neurologic events occurred in 2 (10.0%) patients. At 3 months, there was a 90.0% remission rate (95% CI ,68.3-98.8) with 85.0 % complete remissions (CRs) and 5.0% partial remissions (PRs) accessed by PET-CT. The duration of responses currently ranges from 3.7 months to19.1 months. All patients (17/20) who achieved CRs are ongoing, and the current median duration of all CRs is 13.2 months. Our results indicated that patients with relapsed, refractory and high-risk B cell lymphoma who received sequential infusion of anti-CD22 and anti-CD19 CAR-T cell therapy following HSCT had high rates of durable remission, with safety profile. Anti-CD22 and Anti-CD19 CAR-T cell therapy following HSCT may become a useful treatment approach for relapsed , refractory B cell lymphoma and high-risk B cell lymphoma. Disclosures No relevant conflicts of interest to declare.

Direct Comparison of In Vivo Fate of Second and Third-Generation CD19-Specific Chimeric Antigen Receptor (CAR)-T Cells in Patients with B-Cell Lymphoma: Reversal of Toxicity from Tonic Signaling

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1851-1851 ◽  
Author(s):  
Diogo Gomes da Silva ◽  
Malini Mukherjee ◽  
Madhuwanti Srinivasan ◽  
Olga Dakhova ◽  
Hao Liu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
2Nd Generation ◽  
Car T Cells ◽  
Car T ◽  
Equity Ownership

Abstract Although adoptive transfer of T cells with second-generation CD19-specific CARs containing CD28 or 4-1BB costimulatory endodomains shows remarkable clinical efficacy against B cell malignancies, the optimal choice of costimulatory domains in these and other CARs remains controversial. Depending on the precise CAR structure and specificity, individual endodomains may be associated with deleterious ligand-independent tonic signaling in the transduced T cell. Long et al. (Nat Med 2015) established the CD28 co-stimulatory endodomain can have a toxic tonic signaling effect, but it is unclear if tonic 4-1BB signaling may have deleterious consequences as well, and if such effects can be reversed. We therefore modeled tonic CAR signaling in T cells by transducing them with gammaretroviral vectors expressing 2nd-generation CD19.CAR constructs containing either the CD28 or 4-1BB costimulatory endodomain (in addition to the CD3-ζ chain endodomain). Compared to CAR-T cells with the CD28 endodomain alone, those with 4-1BB alone expanded 70% more slowly following transduction. Impaired expansion of 4-1BB CD19.CAR-T cells was coupled with a 4-fold increase in apoptosis and a gradual downregulation of CAR expression, and was a consequence of 4-1BB-associated tonic TRAF2-dependent signaling, leading to activation of NF-κB, upregulation of Fas and augmented Fas-dependent activation-induced T cell death (AICD). Moreover, expression of 4-1BB CAR from a gammaretroviral vector increased tonic signaling through a self-amplifying/positive feedback effect on the retroviral LTR promoter. Because of the toxicity of 4-1BB in our gammaretroviral CAR.CD19 construct (manifest by delayed expansion and increased apoptosis) we could not directly compare the in vivo fate of T cells expressing CAR.CD19 4-1BB with that of co-administered CAR.CD19 CD28 T cells in patients with lymphoma. We found, however, that the adverse effects of tonic 4-1BB costimulation could be overcome in a 3rd-generation CAR.CD19 vector, containing both CD28 and 4-1BB costimulatory molecules in tandem. We thus compared the fate of a 3rd-generation vector containing both CD28 and 4-1BB costimulatory domains with that of a 2nd-generation vector containing CD28 alone. Six patients with refractory/relapsed diffuse large B-cell lymphoma received 2 cell populations, one expressing 2nd and one expressing 3rd generation vectors. To determine whether CD28 alone was optimal (which would suggest 4-1BB is antagonistic) or whether 4-1BB had an additive or synergistic effect contributing to superior persistence and expansion of the CD28-41BB combination, patients were simultaneously infused with 1-20×106 of both 2nd and 3rd generation CAR+ T cells/m2 48-72 hours after lymphodepletion with cyclophosphamide (500 mg/m2/d) and fludarabine (30 mg/m2/d) × 3. Persistence of infused T cells was assessed in blood by CD19.CAR qPCR assays specific for each CAR. Molecular signals peaked approximately 2 weeks post infusion, remaining detectable for up to 6 months. The 3rd-generation CAR-T cells had a mean 23-fold (range 1.1 to 109-fold) higher expansion than 2nd-generation CAR-T cells and correspondingly longer persistence. Two patients had grade 2 cytokine release syndrome, with elevation of proinflammatory cytokines, including IL-6, at the time of peak expansion of T cells. Of the 5 patients evaluable for response, 2 entered complete remission (the longest ongoing for 9 months), 1 has had continued complete remission after autologous stem cell transplantation, 1 had a partial response, and 1 progressed. In conclusion, our data indicate that infusion of T cells carrying a CD19.CAR containing CD28 and 4-1BB endodomains is safe and can have efficacy at every dose level tested. Additionally, in a side-by-side comparison, the 3rdgeneration vector produced greater in vivo expansion and persistence than an otherwise identical CAR-T cell population with CD28 alone. Disclosures Rooney: Cell Medica: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Viracyte: Equity Ownership. Heslop:Celgene: Patents & Royalties, Research Funding; Chimerix: Other: Endpoint adjudication committee; Viracyte: Equity Ownership; Cell Medica: Patents & Royalties: Licensing agreement EBV-specific T cells.

scholarly journals Fatal late-onset CAR T-cell–mediated encephalitis after axicabtagene-ciloleucel in a patient with large B-cell lymphoma

2021 ◽  
Vol 5 (19) ◽  
pp. 3789-3793
Author(s):  
Susanne Jung ◽  
Jochen Greiner ◽  
Stephanie von Harsdorf ◽  
Pavle Popovic ◽  
Roland Moll ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Car T Cells ◽  
Car T Cell ◽  
Large B Cell Lymphoma ◽  
Car T ◽  
Large B Cell

Abstract Treatment with CD19-directed (CAR) T cells has evolved as a standard of care for multiply relapsed or refractory large B-cell lymphoma (r/r LBCL). A common side effect of this treatment is the immune effector cell–associated neurotoxicity syndrome (ICANS). Severe ICANS can occur in up to 30% to 40% of patients treated with axicabtagene-ciloleucel (axi-cel), usually within the first 4 weeks after administration of the dose and usually responding well to steroids. We describe a case of progressive central neurotoxicity occurring 9 months after axi-cel infusion in a patient with r/r LBCL who had undergone a prior allogeneic hematopoietic cell transplant. Despite extensive systemic and intrathecal immunosuppression, neurological deterioration was inexorable and eventually fatal within 5 months. High CAR T-cell DNA copy numbers and elevated levels of interleukin-1 (IL-1) and IL-6 were found in the cerebral spinal fluid as clinical symptoms emerged, and CAR T-cell brain infiltration was observed on autopsy, suggesting that CAR T cells played a major pathogenetic role. This case of unexpected, devastating, late neurotoxicity warrants intensified investigation of neurological off-target effects of CD19-directed CAR T cells and highlights the need for continuous monitoring for late toxicities in this vulnerable patient population.

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.

Long-term follow-up of anti-CD19 CAR T-cell therapy for B-cell lymphoma and chronic lymphocytic leukemia.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 3012-3012 ◽  
Author(s):  
Kathryn Cappell ◽  
Richard Mark Sherry ◽  
James C. Yang ◽  
Stephanie L. Goff ◽  
Danielle Vanasse ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Long Term Adverse Effects

3012 Background: T cells expressing anti-CD19 chimeric antigen receptors (CARs) can cause complete remissions of relapsed lymphoma. We conducted the first clinical trial of anti-CD19 CAR T cells to show responses against lymphoma. This CAR was later developed as axicabtagene ciloleucel. Here, we aimed to assess the long-term durability of remissions and the long-term adverse effects after anti-CD19 CAR T-cell therapy. Methods: Between 2009 and 2015, we treated 43 patients with anti-CD19 CAR T cells preceded by conditioning chemotherapy of cyclophosphamide plus fludarabine (NCT00924326). Three patients were re-treated for a total of 46 CAR T-cell treatments. Twenty-eight patients had aggressive lymphoma (diffuse large B-cell lymphoma or primary mediastinal B cell lymphoma), eight patients had low-grade lymphoma (five with follicular lymphoma and 1 each with splenic marginal zone lymphoma, mantle cell lymphoma, and unspecified low-grade non-Hodgkin lymphoma), and seven patients had chronic lymphocytic leukemia (CLL). Patients were treated in three cohorts that differed in the CAR T-cell production process and conditioning chemotherapy dose. Results: Of the 43 treated patients, 63% had chemotherapy-refractory lymphoma. Patients had received a median of 4 previous lines of therapy. The median CAR+ T cell dose per kilogram was 2X10^6. The overall remission rate was 76% with 54% complete remissions (CR) and 22% partial remissions (PR). Patients with CR had higher median peak blood CAR levels (86 CAR+ cells/µL) than those who did not have CR (16 CAR+ cells/µL, P= 0.0041). Long-term adverse effects were rare except for B-cell depletion and hypogammaglobulinemia, which both improved over time. Conclusions: This is the longest follow-up study of patients who received anti-CD19 CAR T cells. Anti-CD19 CAR T cells cause highly durable remissions of relapsed B-cell lymphoma and CLL, and long-term adverse effects of anti-CD19 CAR T cells were rare and usually mild. Clinical trial information: NCT00924326 . [Table: see text]

scholarly journals Analysis of CAR-T and Immune Cells within the Tumor Micro-Environment of Diffuse Large B-Cell Lymphoma Post CAR-T Treatment By Multiplex Immunofluorescence

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 678-678 ◽  
Author(s):  
Pei-Hsuan Chen ◽  
Mikel Lipschitz ◽  
Kyle Wright ◽  
Philippe Armand ◽  
Caron A. Jacobson ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Cd8 T Cells ◽  
Research Funding ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Abstract BACKGROUND: Axicabtagene ciloleucel is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy that shows efficacy in patients with refractory diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma and transformed follicular lymphoma after failure of conventional therapy. However, the exact mechanism of anti-tumor immunity is poorly understood, in part due to the dearth of data on the events in the tumor micro-environment (TME) that occur upon exposure to CAR-T cells. We sought to quantify and characterize both CAR-T cells and non-CAR T cells within the TME of DLBCL using tissue biopsy samples collected in the ZUMA-1 multicenter trial of CAR-T cell therapy for patients with refractory DLBCL. METHODS: Tumor samples obtained from patients 5-30 days (median 10 days) after CAR-T infusion ("CAR-treated", n=14) and randomly-selected untreated ("untreated ", n=15) archival DLBCL tissue samples were analyzed by multiplex immunofluorescence using formalin-fixed, paraffin embedded tissue sections, with successive labeling by the primary antibodies KIP-1 and/or KIP-3 (recognizing separate CD19 CAR epitopes), PAX5, PD-1, CD4, and CD8, followed by secondary amplification and tyramide-conjugated fluorophores. For each case, at least 3 representative 20x fields of view were selected and imaged using a multispectral imaging platform. Two specific image analysis algorithms were designed to accurately identify CD4 and CD8 T cells and PAX5+ DLBCL cells simultaneously, then to threshold PD-1 and KIP-1/-3 by relative fluorescent units (RFU) in each phenotype. RESULTS: We identified CAR T-cells within the fixed biopsy samples of CAR-treated DLBCLs by immunostaining with CAR T-cell specific antibody KIP-1; at the timepoints analyzed, CAR T-cells comprised only a small minority of total T- cells (<2%) and included CD4+ and CD8+ T-cells. Immunostaining with a second antibody, KIP-3, validated the presence of CAR T-cells in these cases and confirmed the KIP-1 results. Expression of the T cell activation marker PD-1 was detected among majority of KIP-1+ cells. Further analysis that included KIP1-negative cells revealed that the percentage of CD8+ cells co-expressing PD-1 across all CD8+ cells was higher in the CAR-treated DLBCLs compared to the untreated DLBCLs (mean 50.1% vs 17.5%, p<0.0001 with unpaired t test ), indicating CD8 T cell activation within the tumor environment. In contrast, PD-1 positivity across CD4+ T cells were equivalent between the two groups (mean 21.8% vs 21.6%, ns with unpaired t test). The percentages of total, CD4+, and CD8+ T-cell populations in the TME were similar between the CAR-treated DLBCL and untreated biopsies. CONCLUSIONS: CD4+ and CD8+ CAR-T cells can be detected in CAR-treated DLBCL patient tissue biopsies by multiplex immunofluorescence. At the time points analyzed to date, CAR-T cells comprise only a small percentage of all T-cells (<2%) within the TME. However, the presence of gene marked T cells with downregulated CAR protein expression is also possible. The activation marker PD-1 is preferentially expressed by KIP-1-negative CD8+ T cells compared to CD4+ T cells in CAR-T treated DLBCLs relative to untreated DLBCLs. These data implicate preferential activation of CD8+ non-CAR "by-stander" T-cells in the post CAR-T TME, and the possible benefit of combining PD-1 blockade with CAR-T therapy in DLBCL. *PH.C and M.L share equal contribution. Disclosures Armand: Otsuka: Research Funding; Affimed: Consultancy, Research Funding; Pfizer: Consultancy; Infinity: Consultancy; Adaptive: Research Funding; Merck: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Roche: Research Funding; Tensha: Research Funding. Roberts:KITE: Employment. Rossi:KITE: Employment. Bot:KITE: Employment. Go:KITE: Employment. Rodig:Merck: Research Funding; Bristol Myers Squibb: Research Funding; Affimed: Research Funding; KITE: Research Funding.

scholarly journals CAR T cell therapy in B-cell acute lymphoblastic leukaemia: Insights from mathematical models

2020 ◽  
Author(s):  
Odelaisy León-Triana ◽  
Soukaina Sabir ◽  
Gabriel F. Calvo ◽  
Juan Belmonte-Beitia ◽  
Salvador Chulián ◽  
...  
Keyword(s):  
Mathematical Model ◽  
T Cells ◽  
T Cell ◽  
Side Effects ◽  
B Cell ◽  
Target Cells ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

AbstractImmunotherapies use components of the patient immune system to selectively target cancer cells. The use of CAR T cells to treat B-cell malignancies – leukaemias and lymphomas– is one of the most successful examples, with many patients experiencing long-lasting complete responses to this therapy. This treatment works by extracting the patient’s T cells and adding them the CAR group, which enables them to recognize and target cells carrying the antigen CD19+, that is expressed in these haematological tumors.Here we put forward a mathematical model describing the time response of leukaemias to the injection of CAR T-cells. The model accounts for mature and progenitor B-cells, tumor cells, CAR T cells and side effects by incorporating the main biological processes involved. The model explains the early post-injection dynamics of the different compartments and the fact that the number of CAR T cells injected does not critically affect the treatment outcome. An explicit formula is found that provides the maximum CAR T cell expansion in-vivo and the severity of side effects. Our mathematical model captures other known features of the response to this immunotherapy. It also predicts that CD19+ tumor relapses could be the result of the competition between tumor and CAR T cells analogous to predator-prey dynamics. We discuss this fact on the light of available evidences and the possibility of controlling relapses by early re-challenging of the tumor with stored CAR T cells.

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