scholarly journals Polymorphonuclear myeloid-derived suppressor cells impair the anti-tumor efficacy of GD2.CAR T-cells in patients with neuroblastoma

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nicola Tumino ◽  
Gerrit Weber ◽  
Francesca Besi ◽  
Francesca Del Bufalo ◽  
Valentina Bertaina ◽  
...  
Keyword(s):  
Gene Expression ◽  
Clinical Trial ◽  
T Cells ◽  
T Cell ◽  
High Risk ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

AbstractThe outcome of patients affected by high-risk or metastatic neuroblastoma (NB) remains grim, with ≥ 50% of the children experiencing relapse or progression of the disease despite multimodal, intensive treatment. In order to identify new strategies to improve the overall survival and the quality of life of these children, we recently developed and optimized a third-generation GD2-specific chimeric antigen receptor (CAR) construct, which is currently under evaluation in our Institution in a phase I/II clinical trial (NCT03373097) enrolling patients with relapsed/refractory NB. We observed that our CAR T-cells are able to induce marked tumor reduction and even achieve complete remission with a higher efficiency than that of other CAR T-cells reported in previous studies. However, often responses are not sustained and relapses occur. Here, we demonstrate for the first time a mechanism of resistance to GD2.CAR T-cell treatment, showing how polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) increase in the peripheral blood (PB) of NB patients after GD2.CAR T-cell treatment in case of relapse and loss of response. In vitro, isolated PMN-MDSC demonstrate to inhibit the anti-tumor cytotoxicity of different generations of GD2.CAR T-cells. Gene-expression profiling of GD2.CAR T-cells “conditioned” with PMN-MDSC shows downregulation of genes involved in cell activation, signal transduction, inflammation and cytokine/chemokine secretion. Analysis of NB gene-expression dataset confirms a correlation between expression of these genes and patient outcome. Moreover, in patients treated with GD2.CAR T-cells, the frequency of circulating PMN-MDSC inversely correlates with the levels of GD2.CAR T-cells, resulting more elevated in patients who did not respond or lost response to the treatment. The presence and the frequency of PMN-MDSC in PB of high-risk and metastatic NB represents a useful prognostic marker to predict the response to GD2.CAR T-cells and other adoptive immunotherapy. This study underlines the importance of further optimization of both CAR T-cells and clinical trial in order to target elements of the tumor microenvironment.

scholarly journals B Cell Maturation Antigen-Specific CAR T Cells for Relapsed or Refractory Multiple Myeloma: A Meta-Analysis

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3113-3113 ◽  
Author(s):  
Nico Gagelmann ◽  
Francis Ayuketang Ayuk ◽  
Djordje Atanackovic ◽  
Nicolaus Kroeger
Keyword(s):  
T Cells ◽  
T Cell ◽  
High Risk ◽  
Research Funding ◽  
Response Rates ◽  
Overall Response ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Background Cellular immunotherapies represent an enormously promising strategy for relapsed/refractory multiple myeloma (RRMM). Chimeric antigen receptor (CAR) T cells targeting B cell maturation antigen (BCMA) have shown impressive results in early-phase clinical studies. Here, we summarize the current body of evidence on the role of anti-BCMA CAR T cell therapy for RRMM. Methods We performed a systematic literature review to identify all publicly available prospective studies. We searched Medline, Cochrane trials registry, and www.clinicaltrials.gov. To include the most recent evidence, meeting abstracts from international hematology congresses were added. A conventional meta-analysis was conducted using meta and metafor packages in R statistical software. Pooled event rates and 95% confidence intervals (CIs) were calculated using the inverse variance method within a random-effects framework. Main efficacy outcomes were overall response, complete response (CR), and minimal residual disease (MRD). Furthermore, relapse rates, progression-free survival, and overall survival were evaluated. In terms of safety, outcomes were cytokine release syndrome (CRS), neurotoxicity, and hematologic toxic effects. Results Fifteen studies comprising a total of 285 patients with heavily pretreated RRMM were included in quantitative analyses. Patients received a median of seven prior treatment lines (such as proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies, stem cell transplantation) which included autologous stem cell transplantation in 90% of patients. The median age of patients was 59 years and median follow-up duration ranged from 1.1 to 11.3 months. Most studies used 4-1BB (or CD137), a member of the TNF receptor superfamily, as an activation-induced T-cell costimulatory molecule. Most studies used fludarabine and cyclophosphamide for lymphodepletion while one study used busulfan and cyclophosphamide and one study used cyclophosphamide only. Most studies used the former Lee criteria for CRS grading. Anti-BCMA CAR T cells resulted in a pooled overall response of 82% (95% CI, 74-88%). The pooled proportion of CR in all evaluable patients was 36% (95% CI, 24-50%). Within responders, the pooled proportion of MRD negativity was 77% (95% CI, 67-85%). Higher dose levels of infused CAR+ cells were associated with higher overall response rates resulting in a pooled proportion of 88% (95% CI, 78-94%). In addition, peak CAR T cell expansion appeared to be associated with responses.The presence of high-risk cytogenetics appeared to be associated with lower overall response rates resulting in a pooled proportion of 68% (95% CI, 47-83%). The presence of extramedullary disease at time of infusion did not influence outcome and was associated with similar response rates compared with RRMM patients who did not have extramedullary disease, resulting in a pooled proportion of 78% (95% CI, 47-93%). The pooled relapse rate of all responders was 45% (95% CI, 27-64%) and the median progression-free survival was 10 months. In terms of overall survival, pooled survival rates were 84% (95% CI, 60-95%) at last follow-up (median, 11 months). In terms of safety, the pooled proportion of CRS of any grade was 69% (95% CI, 51-83%). Notably, the pooled proportions of CRS grades 3-4 and neurotoxicity were 15% (95% CI, 10-23%) and 18% (95% CI, 10-31%). Peak CAR T cell expansion appeared to be more likely in the setting of more severe CRS in three studies. Most hematologic toxic effects of grade 3 or higher were neutropenia (85%), thrombocytopenia (70%), and leukopenia (60%). Conclusion Anti-BCMA CAR T cells showed high response rates, even in high-risk features such as high-risk cytogenetics and extramedullary disease at time of CAR T cell infusion. Toxicity was manageable across all early-phase studies. However, almost half of the patients who achieved a response eventually relapsed. Larger studies with longer follow-up evaluating the association of response and survival are needed. Disclosures Ayuk: Novartis: Honoraria, Other: Advisory Board, Research Funding. Kroeger:Medac: Honoraria; Sanofi-Aventis: Honoraria; Neovii: Honoraria, Research Funding; Riemser: Research Funding; JAZZ: Honoraria; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; DKMS: Research Funding.

A killer sidekick for antitumor T cells

2019 ◽  
Vol 11 (479) ◽  
pp. eaaw5325
Author(s):  
Christian S. Hinrichs
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
Car T Cell ◽  
Car T

Engineered NK cells kill myeloid-derived suppressor cells to aid CAR-T cell antitumor responses.

Phase 1 trial of anti-CD19 chimeric antigen receptor T (CAR-T) cells with tumor necrosis alfa receptor superfamily 19 (TNFRSF19) transmembrane domain.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 2539-2539 ◽  
Author(s):  
Paolo Fabrizio Caimi ◽  
Jane Reese ◽  
Folashade Otegbeye ◽  
Dina Schneider ◽  
Kamal Chamoun ◽  
...  
Keyword(s):  
Clinical Trial ◽  
T Cells ◽  
T Cell ◽  
Transmembrane Domain ◽  
Clinical Activity ◽  
Rapid Progression ◽  
Binding Motif ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

2539 Background: AntiCD19 CAR-T cells have shown encouraging anti-lymphoma activity. Decreasing the time from apheresis to CAR-T infusion can make this therapy available to pts with rapid progression. We present the interim results of a phase I clinical trial using on-site CAR-T manufacture. Methods: Adult pts with r/r CD19+ B cell lymphomas who failed ≥ 2 lines of therapy were enrolled. Autologous T cells were transduced with a lentiviral vector (Lentigen Technology, Inc,LTG1563) encoding an antiCD19 binding motif, CD8 linker and TNFRSF19 transmembrane region, and 4-lBB/CD3z domains. GMP-compliant manufacture was done using CliniMACS Prodigy, in a 12-day culture. Dose levels were 0.5, 1 and 2 x 106 CAR-T cells/kg. Lymphodepletion was done with cyclophosphamide (60mg/kg x 1) and fludarabine (25mg/m2/d x 3). Results: 7 pts (4 women, 3 men) were enrolled. Median age was 60y [range 43-69]. Diagnoses were DLBCL (n = 3) PMBCL, follicular lymphoma (FL), transformed FL, and transformed lymphoplasmacytic lymphoma; with a median of 4 previous treatments. Six pts had symptomatic refractory disease. CAR-T cell product manufacture was successful in all pts. Mean transduction rate was 44% [range 29-57]. CAR-T cell doses were 0.5 x 106/kg (n = 3) and 1 x 106/kg (n = 4). Median apheresis to infusion time was 13 days [range 13–20], 5 products were infused fresh. CAR-T persistence based on vector sequence, peaked in peripheral blood MNCs between days 14-21. Five pts are evaluable for safety. CRS grade 1 - 2 (Lee) occurred in 4 pts; with 3 requiring treatment. Grade 4 CRES (CARTOX-10) occurred in 1 pt, with resolution after corticosteroids; considered a DLT as it lasted more than 72 hours. No treatment-related mortality has occurred. 4/5 evaluable pts have achieved complete response. One pt did not respond and died. After a median follow up 3 months, all responding pts are alive and 1 relapsed 6 mo after treatment. Conclusions: Second generation antiCD19 CAR-T cells with TNFRS19 transmembrane domain have clinical activity against refractory NHL. Short manufacture time achieved by local CAR-T cell manufacture with the CliniMACS Prodigy enables treatment of a very high risk NHL population. Clinical trial information: NCT03434769.

scholarly journals First-in-Human CD4 CAR Clinical Trial on Peripheral T-Cell Lymphoma

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2881-2881
Author(s):  
Hongyu Zhang ◽  
Jia Feng ◽  
Wenli Zhang ◽  
Qi Chen ◽  
Yuanzhen Cao ◽  
...  
Keyword(s):  
Clinical Trial ◽  
T Cells ◽  
T Cell ◽  
Sézary Syndrome ◽  
Sezary Syndrome ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Background CD19 CAR T cell therapy has achieved success in treating acute lymphoblastic leukemia. However, the treatment for Sezary syndrome, an aggressive form of cutaneous peripheral T cell lymphoma (PTCL) has remained a challenge. Despite patients with Sezary syndrome typically receiving multiple treatments within their disease progression, the prognosis is poor with 5 year survival rate of only 24%. Therefore, it is crucial to establish a novel treatment for PTCLs. CD4 is uniformly expressed on most mature T cell lymphoma, which makes it a promising target for treating PTCLs. Here, we present the efficacy of CD4 CAR T cell in our preclinical study and the success in level 1 dose escalation clinical trial on patients with Sezary syndrome. Methods We engineered a CD4 CAR with scFv (single-chain variable fragment) with CD28 and 4-1BB co-activators fused to CD3zeta and a leader sequence of CD8. The efficacy of CD4 CAR was tested with CD4+ leukemic cell line, primary CD4+ PTCL patient samples and multiple mouse models. An alemtuzumab safety switch has also been established to ensure the elimination of CAR T cells following tumor eradication. Children and adults with PTCLs were enrolled in our phase 1 dose escalation trial to evaluate the safety and efficacy of CD4 CAR T cell antitumor activity. Results Coculture assays results showed that CD4 CAR T cells displayed profound tumor killing effects in leukemia cell lines, primary patient samples and multiple mouse model systems. Our preclinical findings suggest that CD4 CAR T cells is an effective approach in treating PTCLs. Patients enrolled in the phase 1 dose escalation trial have shown remarkable response to CD4 CAR T cells treatment. Noticeably, a 54-yr-old patient diagnosed with Sezary syndrome had achieved complete remission with CD4 CAR T cell therapy. Prior to admission, he had been having symptoms of erythroderma, pruritus and scaling of the skin for over 10 years and had been resistant to multiple lines of chemotherapy. Before the initiation of CAR therapy, patient's body skin has extensive leukemia infiltrate (Fig. 1A) confirmed with skin biopsy (Fig. 1B) with bone marrow and blood comprising 50% leukemic cells (Fig. 1C). Patient received a total dose of 3x10^6 /kg single dose CAR T cells, following which fluconazole and valacyclovir were administrated for infection prophylaxis. Since patient received CD4 CAR T cell infusion, the percentage of CAR T cells (Fig 1. D) in peripheral blood had continue to increase as well as NK cells. (Fig 1. E) On day 13, patient had achieved complete remission with the percentage of leukemia cells in blood decreased to zero (Fig. 1C). On day 28, the appearance of the skin had undergone drastic change from what was before the treatment. Noticeable skin regeneration on both legs of the patients was observed (Fig 1. F). Flow cytometry of bone marrow and peripheral blood confirmed the absence of tumor cells. In addition, Skin biopsy on multiple sites demonstrated absence of leukemia infiltrates post CAR treatment (Fig. 1G). Patient was subsequently discharged with no additional medication needed. Throughout the treatment, patient had developed no infections with Grade II CRS toxicity noted. No other toxicities were observed. Updated results on other patients enrolled in this clinical trial including adverse events will be presented. Conclusion Our first-in-human clinical trial demonstrates promising efficacy of CD4 CAR T cell therapy in treating patients with refractory Sezary syndrome. cCAR is able to eradicate leukemia blasts, exerting a profound tumor killing effect that is superior to traditional chemotherapies. Disclosures Pinz: iCell Gene Therapeutics LLC: Employment. Ma:iCAR Bio Therapeutics Ltd: Employment. Wada:iCell Gene Therapeutics LLC: Employment. Ma:iCell Gene Therapeutics LLC: Consultancy, Equity Ownership, Research Funding; iCAR Bio Therapeutics Ltd: Consultancy, Equity Ownership, Research Funding.

scholarly journals Selectively targeting myeloid-derived suppressor cells through TRAIL receptor 2 to enhance the efficacy of CAR T cell therapy for treatment of breast cancer

2021 ◽  
Vol 9 (11) ◽  
pp. e003237
Author(s):  
Saisha A Nalawade ◽  
Paul Shafer ◽  
Pradip Bajgain ◽  
Mary K McKenna ◽  
Arushana Ali ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nuclear Translocation ◽  
Suppressor Cells ◽  
T Cell Proliferation ◽  
Myeloid Derived Suppressor Cells ◽  
Tumor Site ◽  
Costimulatory Receptor ◽  
Car T Cells ◽  
Car T

BackgroundSuccessful targeting of solid tumors such as breast cancer (BC) using chimeric antigen receptor (CAR) T cells has proven challenging, largely attributed to the immunosuppressive tumor microenvironment (TME). Myeloid-derived suppressor cells (MDSCs) inhibit CAR T cell function and persistence within the breast TME. To overcome this challenge, we have developed CAR T cells targeting tumor-associated mucin 1 (MUC1) with a novel chimeric costimulatory receptor that targets tumor necrosis factor–related apoptosis-inducing ligand receptor 2 (TR2) expressed on MDSCs.MethodsThe function of the TR2.41BB costimulatory receptor was assessed by exposing non-transduced (NT) and TR2.41BB transduced T cells to recombinant TR2, after which nuclear translocation of NFκB was measured by ELISA and western blot. The cytolytic activity of CAR.MUC1/TR2.41BB T cells was measured in a 5-hour cytotoxicity assay using MUC1+ tumor cells as targets in the presence or absence of MDSCs. In vivo antitumor activity was assessed using MDSC-enriched tumor-bearing mice treated with CAR T cells with or without TR2.41BB.ResultsNuclear translocation of NFκB in response to recombinant TR2 was detected only in TR2.41BB T cells. The presence of MDSCs diminished the cytotoxic potential of CAR.MUC1 T cells against MUC1+ BC cell lines by 25%. However, TR2.41BB expression on CAR.MUC1 T cells induced MDSC apoptosis, thereby restoring the cytotoxic activity of CAR.MUC1 T cells against MUC1+ BC lines. The presence of MDSCs resulted in an approximately twofold increase in tumor growth due to enhanced angiogenesis and fibroblast accumulation compared with mice with tumor alone. Treatment of these MDSC-enriched tumors with CAR.MUC1.TR2.41BB T cells led to superior tumor cell killing and significant reduction in tumor growth (24.54±8.55 mm3) compared with CAR.MUC1 (469.79±81.46 mm3) or TR2.41BB (434.86±64.25 mm3) T cells alone. CAR.MUC1.TR2.41BB T cells also demonstrated improved T cell proliferation and persistence at the tumor site, thereby preventing metastases. We observed similar results using CAR.HER2.TR2.41BB T cells in a HER2+ BC model.ConclusionsOur findings demonstrate that CAR T cells that coexpress the TR2.4-1BB receptor exhibit superior antitumor potential against breast tumors containing immunosuppressive and tumor promoting MDSCs, resulting in TME remodeling and improved T cell proliferation at the tumor site.

scholarly journals Distribution of chimeric antigen receptor-modified T cells against CD19 in B-cell malignancies

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhitao Ying ◽  
Ting He ◽  
Xiaopei Wang ◽  
Wen Zheng ◽  
Ningjing Lin ◽  
...  
Keyword(s):  
Clinical Trial ◽  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Target Cells ◽  
B Cell Malignancies ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Over Time

Abstract Background The unprecedented efficacy of chimeric antigen receptor T (CAR-T) cell immunotherapy of CD19+ B-cell malignancies has opened a new and useful way for the treatment of malignant tumors. Nonetheless, there are still formidable challenges in the field of CAR-T cell therapy, such as the biodistribution of CAR-T cells in vivo. Methods NALM-6, a human B-cell acute lymphoblastic leukemia (B-ALL) cell line, was used as target cells. CAR-T cells were injected into a mice model with or without target cells. Then we measured the distribution of CAR-T cells in mice. In addition, an exploratory clinical trial was conducted in 13 r/r B-cell non-Hodgkin lymphoma (B-NHL) patients, who received CAR-T cell infusion. The dynamic changes in patient blood parameters over time after infusion were detected by qPCR and flow cytometry. Results CAR-T cells still proliferated over time after being infused into the mice without target cells within 2 weeks. However, CAR-T cells did not increase significantly in the presence of target cells within 2 weeks after infusion, but expanded at week 6. In the clinical trial, we found that CAR-T cells peaked at 7–21 days after infusion and lasted for 420 days in peripheral blood of patients. Simultaneously, mild side effects were observed, which could be effectively controlled within 2 months in these patients. Conclusions CAR-T cells can expand themselves with or without target cells in mice, and persist for a long time in NHL patients without serious side effects. Trial registration The registration date of the clinical trial is May 17, 2018 and the trial registration numbers is NCT03528421.

scholarly journals CD22 CAR Optimization for Improved in-Human Activity Following Inadequate CD22 CAR Activity in Phase 1 Clinical Trial PLAT-04

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 403-403
Author(s):  
Corinne Summers ◽  
Blake Baxter ◽  
Colleen Annesley ◽  
Jason Yokoyama ◽  
Stephanie Rhea ◽  
...  
Keyword(s):  
Clinical Trial ◽  
T Cells ◽  
T Cell ◽  
Phase 1 ◽  
Chromium Release Assay ◽  
Phase 1 Clinical Trial ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

Abstract Background: CD19 targeting chimeric antigen receptor (CAR) T cells have induced unprecedented remission rates in high-risk precursor B Acute Lymphoblastic Leukemia (ALL); however recurrent disease with CD19 antigen escape variants is not uncommon. Therefore, we developed a novel CD22 targeting CAR, and following preclinical validation, tested it in a first-in-human pediatric and young adult phase 1 clinical trial, PLAT-04 (NCT03244306). Four subjects were treated at 2 dose levels (DL) (1x10 6/kg (DL1) and 3x10 6/kg (DL2)). The CD22 CAR T cell product (SCRI-CAR22v1) was successfully manufactured (n=4) and no dose limiting toxicity (DLTs), cytokine release syndrome (CRS) or neurotoxicity was observed. However, all subjects had minimal CAR T cell expansion, with 3 of 4 subjects demonstrating persistent or progressive disease at day 21 evaluation despite continued CD22 expression on leukemic blasts. Based on the poor in vivo expansion and lack of activity, enrollment was voluntarily halted to interrogate and optimize the CAR construct for enhanced performance. Methods: Human T cells were transduced to express one of two CD22 CAR constructs. We designed SCRI-CAR22v2, a CD22 CAR that utilizes the same scFv as SCRI-CAR22v1 but with a shorter linker between M971 VH and VL and a shorter hinge with differing transmembrane region, and both using CD8 alpha (Figure A). This construct maintained the truncated EGFR extracellular tag (EGFRt) for tracking and potential in vivo suicide mechanism. The two transduced CAR T cell products were compared preclinically by flow cytometry, chromium release assay and in an in vivo murine model to understand differing T cell activity between the CAR constructs. Additionally, SCRI-CAR22v2 is currently under investigation in a dose finding phase 1 clinical trial, PLAT-07 (NCT04571138). Results: Following use of cetuximab-APC and biotinylated anti-human Fab antibody for surface EGFRt and CAR detection, the SCRI-CAR22v1 expresses lower levels of EGFRt but similar CAR levels on the cell surface demonstrated by MFI (Figure B). Biotinylated, soluble CD22 antigen was also used to evaluate CD22 CAR receptor activity and, as measured by MFI, a higher affinity is suggested via SCRI-CAR22v2 as compared to SCRI-CAR22v1 (Figure B). K562 cells expressing low, medium or high CD22 were used to evaluate the impact of surface antigen expression on the CAR activity level. SCRI-CAR22v2 demonstrates improved targeted cell lysis at all 3 antigen quantity levels by chromium release assay (Figure C). In NSG mice inoculated with Raji tumor cells expressing ffluc, SCRI-CAR22v2 demonstrated improved survival compared to SCRI-CAR22v1 (Figure D) and clearance of Raji tumor cells (Figure E). Based on this promising preclinical data, we initiated enrollment onto PLAT-07, a phase 1 dose finding trial (2x10 5cells/kg (DL1), 5x10 5cells/kg (DL2) and 1x10 6cells/kg (DL3)) of SCRI-CAR22v2. To date, 3 subjects have been enrolled and successfully infused at DL1. All had prior CD19-CAR therapy and 2 lacked CD19 leukemic expression at the time of SCRI-CAR22v2 infusion. At the time of cell infusion, one subject had only extramedullary disease, one had MRD of <1% and one subject had a larger disease burden of 30% ALL. None experienced a DLT and all were MRD negative in the bone marrow at day 28 and the subject with EMD demonstrated a complete metabolic response by PET scan. Figure F exhibits the improved expansion and engraftment of the SCRI-CAR22v2 cells as compared to SCRI-CAR22v1 DL1 (n=3) and DL2 (n=1), and higher peak levels of CD22 CAR T cells as compared to SCRI-CAR22v1 DL1 and DL2 (Figure G). Conclusions: Despite encouraging preclinical data, SCRI-CAR22v1 demonstrated poor expansion and engraftment in a Phase 1 trial. Notably, minor CAR alterations lead to encouraging in-human activity in early clinical findings. Our experience suggests a shorter linker and hinge as well as incorporation of an CD8 alpha transmembrane region improves the clinical activity of CD22 targeted CAR T cells in subjects with recurrent disease following CD19 CAR T cells. Further evaluation is needed to elucidate the critical CAR components and/or assays at the preclinical level that can best predict which CAR should be brought to the clinic for further evaluation. Figure 1 Figure 1. Disclosures Orentas: Lentigen: Patents & Royalties. Jensen: BMS: Patents & Royalties; Umoja Biopharma: Current holder of stock options in a privately-held company, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bluebird Bio: Research Funding. Gardner: Novartis: Consultancy; BMS: Patents & Royalties.

Phase 1 Study of CART-ddBCMA, a CAR-T therapy utilizing a novel synthetic binding domain, for the treatment of subjects with relapsed and refractory multiple myeloma.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 8015-8015
Author(s):  
Matthew J. Frigault ◽  
Elizabeth O'Donnell ◽  
Noopur S. Raje ◽  
Daniella Cook ◽  
Andrew Yee ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
High Risk ◽  
T Cell Activation ◽  
Phase 1 ◽  
Binding Domain ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

8015 Background: CART-ddBCMA is an autologous CAR-T cell therapy encoding a novel non-scFv synthetic binding domain targeting BCMA with a 4-1BB costimulatory motif and CD3-zeta T-cell activation domain. The novel binding domain is based on a computationally-derived triple-helix protein scaffold that is small (73 amino acids), stable, engineered to reduce immunogenicity, and can be modified to bind alternative targets. Methods: ARC-101 (NCT04155749), ARM 1 (CART-ddBCMA) is a Phase 1, multi-center, open-label, dose escalation trial enrolling subjects who have received ≥3 prior regimens, including proteasome inhibitor(s), immuno-modulatory agent(s), and anti-CD38 antibody, or are triple-refractory. Subjects undergo lymphodepletion with fludarabine and cyclophosphamide, then receive CART-ddBCMA as a single infusion. Planned dose levels are 100, 300, and up to 900 x 106 CAR+ T cells. The primary endpoint is incidence of adverse events (AEs), including dose-limiting toxicities (DLTs). Secondary endpoints include clinical response per IMWG criteria, MRD, DOR, PFS, OS, and CAR-T cell kinetics. Results: As of 29 Jan 2021, 10 subjects received CART-ddBCMA, 9 subjects were evaluable, and 1 subject was pending assessment. Median age was 66 years [min:max 54 to 75]. 6 subjects received 100 x 106 CAR+ T cells, and 4 subjects received 300 x 106 CAR+ T cells. Median CAR+ expression was 74.5% (min:max 61-87%) of total T cells. Of the evaluable subjects, median follow-up after cell infusion was 208 days (min:max 45 to 355+ days), 9/9 subjects were penta-refractory, 1 subject was also refractory to BCMA-directed ADC. 8/9 had high-risk cytogenetics (1 subject’s sample not evaluable), and 6/9 subjects had extramedullary disease. No DLTs were reported. Per ASTCT Consensus Grading (Lee et al, 2019), 8 subjects developed G1/2 CRS, 1 subject in the higher dose cohort developed G3 CRS that rapidly resolved with tocilizumab. 1 subject developed G2 ICANS which rapidly resolved with intervention. 7 subjects received tocilizumab; 3 received dexamethasone. ORR was 100% (9/9) per IMWG criteria including 4 sCR, 1 VGPR, and 4 PR. 1 subject with PR relapsed and was retreated. All other subjects have ongoing responses; observations included sFLC normalization and elimination of detectable bone marrow disease by Month 1. Ongoing responses for subjects not yet achieving CR continue to deepen. 7 subjects were evaluable by MRD of which 5 are MRD-negative, and 2 are pending results. CAR-T cell expansion, as measured by vector transgene copies per microgram genomic DNA was observed in all patients. Conclusions: Early efficacy results are encouraging, with 9/9 (100%) ORR and manageable toxicities. 8/9 responses are ongoing and responses continue to deepen. These data are encouraging in high-risk subjects with penta-refractory myeloma. Subjects continue to be enrolled and treated. Clinical trial information: NCT04155749.

A phase I trial of CD19-targeted EGFRt/19-28z/4-1BBL armored chimeric antigen receptor (CAR) modified T cells in patients with relapsed or refractory chronic lymphocytic leukemia.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. TPS7568-TPS7568 ◽  
Author(s):  
Jae Hong Park ◽  
Isabelle Riviere ◽  
Xiuyan Wang ◽  
Brigitte Senechal ◽  
Yvette Bernal ◽  
...  
Keyword(s):  
Clinical Trial ◽  
T Cells ◽  
T Cell ◽  
Phase I ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Comprehensive Treatment ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

TPS7568 Background: Despite the recent progress in the therapy of CLL with BTK, PI3Kδ, and BCL2 inhibitors, CLL remains incurable and patients with high-risk disease features (i.e. del17p, complex karyotype) and patients whose disease progress after treatment with the above targeted agents continue to have extremely poor prognosis. CD19-specific chimeric antigen receptor (CAR) T cell therapy with various 2nd generation CARs (19-28z or 19-41BBz) have demonstrated anti-tumor efficacy in CLL but the complete response (CR) rates in CLL have been suboptimal (20-45%) compared to CR rates in ALL (80-90%). The suboptimal activity of the current 2nd generation CAR T cells can be due to the inhibitory tumor microenvironment (TM) of CLL. We believe one approach to over the hostile TM is through the use of CD19-CAR T cells further modified to express a second costimulatory ligand, 4-1BBL. A binding of 4-1BBL to its cognate receptor enhances T cell proliferation, IL-2 secretion, and survival and cytolytic activity of the T cells compared to 19-28z. 19-41BBz and 1928BBz (Zhao Z et al. Cancer Cell 2015;28:415-428). Methods: This phase I dose escalating trial is a single-center clinical trial (MSKCC) to study the safety and efficacy of autologous EGFRt/19-28z/4-1BBL+ CAR T cells in patients with relapsed CLL. Given the concern for potential systemic toxicity the vector includes a "safety switch" in the form of a gene for the expression of truncated form of human epidermal growth factor receptor (EGFRt). Patients with relapsed CLL are eligible for the trial. Patients will receive conditioning chemotherapy of cyclophosphamide followed by escalating doses of CAR T cells (1x105 – 3x106 CAR T cells/kg). The primary endpoint is safety and maximum tolerated doses of the CAR T ells. Secondary objectives include response assessment by iwCLL criteria. The comprehensive treatment algorithms for CRS and neurotoxicity are based on our CAR T cell experience in other studies. The study will begin enrollment in February 2017 and enroll up to 30 patients. Clinical trial information: Pending.

TRANSCEND CLL 004: Minimal residual disease (MRD) negative responses after lisocabtagene maraleucel (Liso-Cel; JCAR017), a CD19-directed CAR T cell product, in patients (pts) with relapsed/refractory chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL).

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 7501-7501 ◽  
Author(s):  
Tanya Siddiqi ◽  
Kathleen Anne Dorritie ◽  
Jacob Drobnyk Soumerai ◽  
Deborah Marie Stephens ◽  
Jason A Dubovsky ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
High Risk ◽  
Complete Blood Count ◽  
Residual Disease ◽  
Lymphocytic Leukemia ◽  
Cell Product ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

7501 Background: Eradication of MRD in CLL patients may be necessary for deep and durable responses. We assessed safety, pharmacokinetics, and efficacy of liso-cel, an investigational, anti-CD19 CAR T cell product administered as a defined composition of CD4+/CD8+ CAR T cells, in the ongoing phase 1/2 TRANSCEND CLL 004 study. Methods: Eligible pts had CLL/SLL, received ≥2 prior lines of therapy (including Bruton’s tyrosine kinase inhibitors [BTKi] unless medically contraindicated), and had ECOG PS ≤1. Post lymphodepleting chemotherapy, pts received liso-cel infusion at either dose level (DL)1 = 50 × 106 or DL2 = 100 × 106 total CAR+ T cells. Patients were monitored for dose-limiting toxicities (DLTs). Response was assessed by iwCLL 2008 criteria. MRD was assessed by flow cytometry in blood (10−4) and by NGS in bone marrow (BM; 10−6). Results: At data cutoff, 16 pts received liso-cel: DL1, n = 6; DL2, n = 10. 75% of pts had high-risk features ( TP53 mutation, complex karyotype, or del17p); 100% had prior ibrutinib and 50% had prior venetoclax. Median (range) number of prior lines of therapy was 4.5 (2‒11). There was 1 DLT of grade (G) 4 hypertension (DL2). The most common G3/4 treatment-emergent adverse events were cytopenias (thrombocytopenia, 75%; anemia, 69%; neutropenia, 63%; leukopenia, 56%). 1 pt had G3 cytokine release syndrome (CRS); 3 pts had G3 neurological events (NE). Best overall response rate (ORR) in 15 evaluable pts was 87% (13/15). 7 pts (47%) achieved complete remission with/without complete blood count recovery (CR/CRi). ORR at 6 mo was 83% (5/6). 10/15 pts (67%) achieved undetectable MRD (uMRD) in blood by day 30 and in 7/8 pts (88%) in BM. MRD-negative CRs were seen in patients who had failed both BTKi and venetoclax. Median time to peak blood CAR+ T cell level was 16 days (4‒30). Conclusions: In this study of heavily pretreated pts with standard- and high-risk CLL/SLL and previous ibrutinib treatment, liso-cel-related toxicities (ie, CRS and NEs), were manageable. Pts rapidly achieved CR/CRi and uMRD. Additional follow-up will be presented. Clinical trial information: NCT03331198.

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