scholarly journals Clinical Responses and Pharmacokinetics of MCARH171, a Human-Derived Bcma Targeted CAR T Cell Therapy in Relapsed/Refractory Multiple Myeloma: Final Results of a Phase I Clinical Trial

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 959-959 ◽  
Author(s):  
Sham Mailankody ◽  
Arnab Ghosh ◽  
Mette Staehr ◽  
Terence J Purdon ◽  
Mikhail Roshal ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Advisory Committees ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Abstract Introduction: BCMA targeted CAR T cell therapy has shown promising results in patients with relapsed/refractory multiple myeloma (MM). Herein, we report on the safety and efficacy of MCARH171, a second generation, human derived BCMA targeted autologous 4-1BB containing CAR T cell therapy, including a truncated epidermal growth factor receptor safety system (Smith EL. Mol Ther 2018). Methods: This is a phase I first in human, dose escalation trial of MCARH171. Patients received conditioning chemotherapy with cyclophosphamide (Cy) 3 gm/m2 as a single dose or fludarabine 30 mg/m2 daily and Cy 300 mg/m2 daily for 3 days followed by MCARH171 infusion in 1-2 divided doses. The trial followed a standard 3+3 design with 4 dose levels where patients received the following mean doses per cohort: (1) 72x106, (2) 137x106, (3) 475x106, (4) 818x106 viable CAR+ T cells. The primary objective was to demonstrate safety, and secondary objectives included efficacy and expansion, and persistence of CAR T cells using PCR from the peripheral blood. The last accrued patient received MCARH171 on Dec 6, 2017 and the data cut-off is July 16, 2018. The study is closed to accrual. Results: 11 patients with relapsed and/or refractory MM were treated. Median number of prior lines of therapy was 6 (range: 4-14), and all patients received prior therapy with a proteasome inhibitor, IMiD, anti-CD38 monoclonal antibody, and high dose melphalan/stem cell transplant. Nine (82%) patients had high-risk cytogenetics and 9 (82%) were refractory to their immediate prior line of treatment. One patient was not evaluable for DLTs given the need for early radiation and steroids for impending spinal cord compression by tumor. There are no DLTs reported. Cytokine release syndrome (CRS) grade 1-2 occurred in 4 patients (40%), grade 3 occurred in 2 (20%), and there was no grade 4-5 CRS. Grade 2 encephalopathy occurred in 1 patient (10%) in the setting of high fevers which resolved in less than 24 hours. There was no grade 3 or higher neurotoxicity observed. Tocilizumab was administered to 3 patients; 2 in cohort 2, and 1 in cohort 3. Laboratory values correlating with CRS reaching grade 3 or requiring Tocilizumab (N=4) compared to those with no or milder CRS (N=6) included peak CRP (mean: 28.5 vs 4.6 mg/dL, p<0.001), IFNg (mean peak fold increase: 271 vs 11-fold, p<0.0001), and peak IL6 before Tocilizumab, as IL6 elevation artificially increases after use (mean: 435 vs 68.7 pg/mL, p<0.005). No significant change was seen in ferritin or fibrinogen compared to baseline. Overall response rate was 64% and the median duration of response was 106 days (range: 17 to 235 days). The peak expansion and persistence of MCARH171 as well as durable clinical responses were dose dependent. Patients who were treated on the first two dose cohorts (≤150 X106 CAR T cells) had a lower peak expansion in the peripheral blood (mean 14,098 copies/µL; N=6), compared to patients who were treated on the third or fourth dose cohort 3-4 (≥450 X106 CAR T cells; N=5), where the mean peak expansion was 90,208 copies/µL (p<0.05). Among the 5 patients who received higher doses (450 X106), 5/5(100%) patients responded. The duration of responses was also related to the cell dose, with 3 of 5 patients (60%) treated in the cohorts receiving ≥450 X106 had clinical responses lasting >6 months compared to only 1 of 6 (16.7%) patients who received lower doses. Two patien have ongoing responses (VGPR) at 7.5+ and 10+ months of follow up. To normalize for dose administered we compared the pharmacokinetics of only patients treated at dose levels 3-4 ( ≥450 X106 CAR T cells). Here, we demonstrate that peak expansion correlated to clinical efficacy, with the 3 durable responders all having peak expansion >85,000 copies/µL (mean: 131,732 copies/µL); compared to transient responders, where the maximum peak expansion was 33,213 copies/µL (mean: 27,922; Figure 1). Conclusions: MCARH171 has an acceptable safety profile with no DLTs reported. A dose-response relationship with toxicity was not clearly observed, as noted by distribution of tocilizumab use across dose cohorts. However, a dose-response relationship was observed with promising clinical efficacy at dose levels of ≥450 X106 CAR T cells. Controlling for dose level, peak expansion correlated with durability of response. These results further support the development of CAR T cells for heavily pre-treated patients with relapsed and refractory MM. Disclosures Mailankody: Janssen: Research Funding; Takeda: Research Funding; Juno: Research Funding; Physician Education Resource: Honoraria. Korde:Amgen: Research Funding. Lesokhin:Takeda: Consultancy, Honoraria; Squibb: Consultancy, Honoraria; Janssen: Research Funding; Genentech: Research Funding; Serametrix, inc.: Patents & Royalties: Royalties; Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding. Hassoun:Oncopeptides AB: Research Funding. Park:Juno Therapeutics: Consultancy, Research Funding; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy; AstraZeneca: Consultancy; Adaptive Biotechnologies: Consultancy; Kite Pharma: Consultancy; Novartis: Consultancy; Shire: Consultancy. Sauter:Juno Therapeutics: Consultancy, Research Funding; Sanofi-Genzyme: Consultancy, Research Funding; Spectrum Pharmaceuticals: Consultancy; Novartis: Consultancy; Precision Biosciences: Consultancy; Kite: Consultancy. Palomba:Pharmacyclics: Consultancy; Celgene: Consultancy. Riviere:Fate Therapeutics Inc.: Research Funding; Juno Therapeutics, a Celgene Company: Membership on an entity's Board of Directors or advisory committees, Research Funding. Landgren:Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Research Funding; Pfizer: Consultancy; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Consultancy; Merck: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Research Funding. Brentjens:Juno Therapeutics, a Celgene Company: Consultancy, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Smith:Celgene: Consultancy, Patents & Royalties: CAR T cell therapies for MM, Research Funding.

scholarly journals Biallelic Loss of BCMA Triggers Resistance to Anti-BCMA CAR T Cell Therapy in Multiple Myeloma

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 14-14
Author(s):  
Mehmet K. Samur ◽  
Mariateresa Fulciniti ◽  
Anil Aktas-Samur ◽  
Abdul Hamid Bazarbachi ◽  
Yu-Tzu Tai ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Publicly Traded ◽  
Advisory Committees ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Chimeric antigen receptor (CAR) T-cell therapy targeting B cell maturation antigen (BCMA) has provided deep (73% - 100%) responses in relapsed/refractory multiple myeloma (MM). However, median PFS has been less than 12 months, and amongst the small number of patients retreated at the time of progression with the same CAR T product, responses have been infrequent. This highlights development of resistance that may preclude effectiveness of the 2ndinfusion, and may also underly relapse following response to the initial CAR-T cell therapy. Here, we have investigated one of the resistance mechanisms using longitudinal single cell transcriptomic and bulk genomic analysis. This patient had relapsed/refractory IgG lambda MM with hypodiploidy and a complex karyotype with t(8;12) (q24;q14), clonal t(11;14) (q13;q32), and clonal deletion 13. Patient received 150x106CAR+ T cells (ide-cel) and achieved partial response, with duration of response of 8 months. The patient was retreated with 450 x106CAR+ T cells at relapse, but with no response. To delineate the resistance mechanism, we evaluated the bone marrow (BM) niche using 37658 cells from eight time points from before 1st CAR T cell infusion to 2 months after 2nd CAR T cell infusion, and identified 13 clusters consisting of hematopoietic cells and MM/plasma cells. Using RT-PCR based detection, we observed engineered CAR T cells only at 2 weeks after first infusion, when maximal CAR T cell expansion was observed. We did not observe infused CAR T cells with single cell RNAseq after 2ndinfusion, but a limited expansion was confirmed using RT-PCR.Re-clustering of the T cell cluster showed an increased proportion of CD4+ helper and T regulatory cells (Treg) 2 weeks after 1st infusion. In contrast, TREG proportion remained constant at the 2nd infusion, suggesting other causes for lack of expansion of CAR-T cells. We also did not identify any significant increase in the proportion of cells expressing immune check point inhibitory markers or in accessory cell types with immune inhibitory function in MM BM. Since we did not delinate a role of the BM milieu mediating suppression of CAR-T cell expansion and function following 2ndinfusion, we next explored tumor intrinsic factors. Soluble BCMA level (produced predominantly by MM cells) was high before the first CAR T cell infusion and dropped significantly to a very low level coinciding with the clinical response; however, it remained low even at the time of relapse with increase burden of MM, indicating a lack of BCMA production by MM cells. We therefore investigated genomic changes in MM cells at the time of relapse. Our single cell analysis of BM samples identified 3 samples (at the time of relapse and post 2ndCAR T cell infusion) with significant numbers of MM cells, evidenced by expression of CD138 and XBP1 (marker of plasma cells), CCND1 (upregulated in this patient with t(11;14)) and lack of RB1 (downregulated in this patient with del13). Imputation of copy number alterations scRNAseq showed that the majority of MM cells had a deletion of 16p, including the BCMA locus located on 16p13.13. We further validated these findings using deep whole exome sequencing (WES) of purified CD138+ cells collected after the second CAR T infusion. Before first CAR T cell infusion, 4% MM cells showed deletion 17p, while after second infusion both WES and scRNAseq prediction showed that del17p and del16p were clonal, and longitudinal scRNAseq analysis indicated that del17p and del16p co-occurred in the same clone. Moreover, WES identified a subclonal nonsense mutation (p.Q38*) in BCMA that creates an early stop codon in the BCMA gene. This biallelic BCMA deletion, acquired with one copy loss and a 2ndloss-of-function mutation, provides the molecular basis for lack of BCMA expression in MM cells at the time of relapse. Our data showed that both TP53 and BCMA had deletion in one allele and mutation in the second allele. These results identify biallelic loss of BCMA locus as a potential resistance mechanism to BCMA targeting therapy. Our results highlight the need to investigate sBCMA as a potential indicator of BCMA loss at relapse, and to carry out detailed transcriptomic or genomic analysis to confirm mutations. Moreover, these data also demonstrate the ability of MM cells to survive without BCMA expression. With the growing number of BCMA targeting therapeutic modalities under development, we would expect to see such occurrences more commonly in the future. Disclosures Fulciniti: NIH: Research Funding. Campbell:BMS: Current Employment, Current equity holder in publicly-traded company. Petrocca:bluebird, bio: Current Employment, Current equity holder in publicly-traded company. Hege:Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Patents & Royalties: numerous, Research Funding; Celgene (acquired by Bristol Myers Squibb): Ended employment in the past 24 months; Mersana Therapeutics: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Arcus Biosciences (Former Board of Directors): Divested equity in a private or publicly-traded company in the past 24 months. Kaiser:BMS: Current Employment, Current equity holder in publicly-traded company. Anderson:Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Sanofi-Aventis: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Millenium-Takeda: Membership on an entity's Board of Directors or advisory committees; Oncopep and C4 Therapeutics.: Other: Scientific Founder of Oncopep and C4 Therapeutics.. Munshi:C4: Current equity holder in private company; Legend: Consultancy; OncoPep: Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; BMS: Consultancy; Janssen: Consultancy; Adaptive: Consultancy; Amgen: Consultancy; AbbVie: Consultancy; Karyopharm: Consultancy; Takeda: Consultancy.

scholarly journals Automated Manufacture of Matched Donor-Derived Allogeneic CD19 CAR T-Cells for Relapsed/Refractory B-ALL Following Allogeneic Stem Cell Transplantation: Toxicity, Efficacy and the Important Role of Lymphodepletion

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 776-776
Author(s):  
Claire Roddie ◽  
Maeve A O'Reilly ◽  
Maria A V Marzolini ◽  
Leigh Wood ◽  
Juliana Dias Alves Pinto ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Advisory Committees ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Peak Car ◽  
Matched Donor

Introduction: 2nd generation CD19 CAR T cells show unprecedented efficacy in B-ALL, but several challenges remain: (1) scaling manufacture to meet patient need and (2) feasibility of generating products from lymphopenic patients post allogeneic stem cell transplant (allo-SCT). To overcome these issues we propose: (1) use of the CliniMACS Prodigy (Miltenyi Biotec), a semi-automated cGMP platform that simplifies CAR T cell manufacture and (2) the use of matched donor T cells to overcome the challenge posed by patient lymphopenia, albeit this may come with a heightened risk of graft versus host disease (GvHD). CARD (NCT02893189) is a Phase I study of matched donor derived CD19 CAR T cells generated on the CliniMACS Prodigy in 14 adult patients with relapsed/refractory (r/r) B ALL following allo-SCT. We additionally explore the requirement for lymphodepletion (LD) in the allogeneic CAR T cell setting and report on the incidence of GvHD with this therapy. Methods: Manufacturing: CARD utilises non-mobilised matched donor leucapheresate to manufacture 2nd generation CD19CAR T cells using a closed CliniMACS® Prodigy/ TransACTTM process. Study design: Eligible subjects are aged 16-70y with r/r B ALL following allo SCT. Study endpoints include feasibility of CD19CAR T cell manufacture from allo-SCT donors on the CliniMACS Prodigy and assessments of engraftment and safety including GvHD. To assess the requirement for LD prior to CD19CAR T cells in lymphopenic post-allo-SCT patients, the study is split into Cohort 1 (no LD) and Cohort 2 (fludarabine (30 mg/m2 x3) and cyclophosphamide (300mg/m2 x3)). To mitigate for the potential GvHD risk, cell dosing on study mirrors conventional donor lymphocyte infusion (DLI) schedules and is based on total CD3+ (not CAR T) cell numbers: Dose 1=1x106/kg CD3+ T cells; Dose 2= 3x106/kg CD3+ T cells; Dose 3= 1x107/kg CD3+ T cells. Results: As of 26 July 2019, 17 matched allo SCT donors were leukapheresed and 16 products were successfully manufactured and QP released. Patient demographics are as follows: (1) median patient age was 43y (range 19-64y); (2) 4/17 had prior blinatumomab and 5/17 prior inotuzumab ozogamicin; (3) 7/17 had myeloablative allo SCT and 10/17 reduced intensity allo SCT of which 6/17 were sibling donors and 12/17 were matched unrelated donors. No patients with haploidentical transplant were enrolled. To date, 12/16 patients have received at least 1 dose of CD19CAR T cells: 7/16 on Cohort 1 and 5/16 on Cohort 2 (2/16 are pending infusion on Cohort 2 and 2/16 died of fungal infection prior to infusion). Median follow-up for all 12 patients is 22.9 months (IQR 2.9-25.9; range 0.7 - 25.9). At the time of CAR T cell infusion, 7/12 patients were in morphological relapse with &gt;5% leukemic blasts. Despite this, CD19CAR T cells were administered safely: only 2/12 patients experienced Grade 3 CRS (UPenn criteria), both in Cohort 1, which fully resolved with Tocilizumab and corticosteroids. No patients experienced ≥Grade 3 neurotoxicity and importantly, no patients experienced clinically significant GvHD. In Cohort 1 (7 patients), median peak CAR expansion by flow was 87 CD19CAR/uL blood whereas in Cohort 2 (5 patients to date), median peak CAR expansion was 1309 CD19CAR/uL blood. This difference is likely to reflect the use of LD in Cohort 2. CAR T cell persistence by qPCR in Cohort 1 is short, with demonstrable CAR in only 2/7 treated patients at Month 2. Data for Cohort 2 is immature, but this will also be reported at the meeting in addition to potential mechanisms underlying the short persistence observed in Cohort 1. Of the 10 response evaluable patients (2/12 pending marrow assessment), 9/10 (90%) achieved flow/molecular MRD negative CR at 6 weeks. 2/9 responders experienced CD19 negative relapse (one at M3, one at M5) and 3/9 responders experienced CD19+ relapse (one at M3, one at M9, one at M12). 4/10 (40%) response evaluable patients remain on study and continue in flow/molecular MRD negative remission at a median follow up of 11.9 months (range 2.9-25.9). Conclusions: Donor-derived matched allogeneic CD19 CAR T cells are straightforward to manufacture using the CliniMACS Prodigy and deliver excellent early remission rates, with 90% MRD negative CR observed at Week 6 in the absence of severe CAR associated toxicity or GvHD. Peak CAR expansion appears to be compromised by the absence of LD and this may lead to a higher relapse rate. Updated results from Cohorts 1 and 2 will be presented. Disclosures Roddie: Novartis: Consultancy; Gilead: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau. O'Reilly:Kite Gilead: Honoraria. Farzaneh:Autolus Ltd: Equity Ownership, Research Funding. Qasim:Autolus: Equity Ownership; Orchard Therapeutics: Equity Ownership; UCLB: Other: revenue share eligibility; Servier: Research Funding; Bellicum: Research Funding; CellMedica: Research Funding. Linch:Autolus: Membership on an entity's Board of Directors or advisory committees. Pule:Autolus: Membership on an entity's Board of Directors or advisory committees. Peggs:Gilead: Consultancy, Speakers Bureau; Autolus: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Human CD83 Targeted Chimeric Antigen Receptor T Cell for the Prevention of Graft Versus Host Disease and Treatment of Myeloid Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 196-196
Author(s):  
Bishwas Shrestha ◽  
Kelly Walton ◽  
Jordan Reff ◽  
Elizabeth M. Sagatys ◽  
Nhan Tu ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Advisory Committees ◽  
Graft Versus Host ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Fund Research

Distinct from pharmacologic immunosuppression, we designed a programmed cytolytic effector T cell that prevents graft versus host disease (GVHD). CD83 is expressed on allo-activated conventional T cells (Tconv) and pro-inflammatory dendritic cells (DCs), which are implicated in GVHD pathogenesis. Therefore we developed a novel human CD83 targeted chimeric antigen receptor (CAR) T cell for GVHD prophylaxis. Here we demonstrate that human CD83 CAR T cells eradicate cell mediators of GVHD, significantly increase the ratio of regulatory T cells (Treg) to allo-activated Tconv, and provide lasting protection from xenogeneic GVHD. Further, we show human, acute myeloid leukemia (AML) expresses CD83 and can be targeted by CD83 CAR T cells. A 2nd generation CD83 CAR was generated with CD3ζ and 41BB costimulatory domain that was retrovirally transduced in human T cells to generate CD83 CAR T cells. The CD83 CAR construct exhibited a high degree of transduction efficiency of about 60%. The CD83 CAR T cells demonstrated robust IFN-γ and IL-2 production, killing, and proliferation when cultured with CD83+ target cells. To test whether human CD83 CAR T cells reduce alloreactivity in vitro, we investigated their suppressive function in allogeneic mixed leukocyte reactions (alloMLR). CD83 CAR T cells were added to 5-day alloMLRs consisting of autologous T cells and allogeneic monocyte-derived DCs at ratios ranging from 3:1 to 1:10. The CD83 CAR T cells potently reduced alloreactive T cell proliferation compared to mock transduced and CD19 CAR T cells. We identified that CD83 is differentially expressed on alloreactive Tconv, compared to Tregs. Moreover, the CD83 CAR T cell efficiently depletes CD83+ Tconv and proinflammatory DCs with 48 hours of engagement. To test the efficacy of human CD83 CAR T cells in vivo, we used an established xenogeneic GVHD model, where mice were inoculated with human PBMCs (25x106) and autologous CD83 CAR (1-10x106) or mock transduced T cells. The CD83 CAR T cells were well tolerated by the mice, and significantly improved survival compared to mock transduced T cells (Figure 1A). Mice treated with CD83 CAR T cells exhibited negligible GVHD target organ damage at day +21 (Figure 1B). Mice inoculated with CD83 CAR T cells demonstrated significantly fewer CD1c+, CD83+ DCs (1.7x106 v 6.2x105, P=0.002), CD4+, CD83+ T cells (4.8x103 v 5.8x102, P=0.005), and pathogenic Th1 cells (3.1x105 v 1.1x102, P=0.005) at day +21, compared to mice treated with mock transduced T cells. Moreover, the ratio of Treg to alloreactive Tconv (CD25+ non-Treg) was significantly increased among mice treated with CD83 CAR T cells (78 v 346, P=0.02), compared to mice injected with mock transduced T cells. Further, CD83 appears to be a promising candidate to target myeloid malignancies. We observed CD83 expression on malignant myeloid K562, Thp-1, U937, and MOLM-13 cells. Moreover, the CD83 CAR T cells effectively killed AML cell lines. Many AML antigens are expressed on progenitor stem cells. Thus, we evaluated for stem cell killing in human colony forming unit (CFU) assays, which demonstrated negligible on-target, off-tumor toxicity. Therefore, the human CD83 CAR T cell is an innovative cell-based approach to prevent GVHD, while providing direct anti-tumor activity against myeloid malignancies. Figure Disclosures Blazar: Kamon Pharmaceuticals, Inc: Membership on an entity's Board of Directors or advisory committees; Five Prime Therapeutics Inc: Co-Founder, Membership on an entity's Board of Directors or advisory committees; BlueRock Therapeutics: Membership on an entity's Board of Directors or advisory committees; Abbvie Inc: Research Funding; Leukemia and Lymphoma Society: Research Funding; Childrens' Cancer Research Fund: Research Funding; KidsFirst Fund: Research Funding; Tmunity: Other: Co-Founder; Alpine Immune Sciences, Inc.: Research Funding; RXi Pharmaceuticals: Research Funding; Fate Therapeutics, Inc.: Research Funding; Magenta Therapeutics and BlueRock Therapeuetics: Membership on an entity's Board of Directors or advisory committees; Regeneron Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Davila:Atara: Research Funding; Celgene: Research Funding; Precision Biosciences: Consultancy; Bellicum: Consultancy; GlaxoSmithKline: Consultancy; Adaptive: Consultancy; Anixa: Consultancy; Novartis: Research Funding.

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, &gt;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 &gt;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 &lt;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 T-Cell Telomere Length As a Biomarker to Predict Outcome in Patients Receiving CAR-T Immunotherapy

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4798-4798
Author(s):  
Enzo Tedone ◽  
Mohammed Sayed ◽  
Tsung-Po Lai ◽  
Aishwarya Sannareddy ◽  
Dheepthi P. Ramasamy ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Telomere Length ◽  
Board Of Directors ◽  
Advisory Committees ◽  
T Cell Therapy ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Abstract Introduction: CAR T-cells remain in a quiescent or dormant state when unstimulated, showing no proliferative activity. In contrast, upon specific antigen stimulation (i.e., CD19) CAR T-cells divide both in-vitro and in-vivo, initiate immune responses and can kill their target cells in the body. However, one of the major physiological immune changes with increased age is the progressive impairment of T-cell responses. This process termed immunosenescence (which may be similar T-cell exhaustion) is associated with the shortening of telomeres, specific DNA repeated sequences that protect the end of linear chromosomes from degradation and fusion with neighbor chromosomes. We aim to investigate change in T-cell telomere length with CAR-T cell therapy and its potential impact on outcome in patients receiving CART immunotherapy. Methods: We enrolled adult patients (age range: 30-80 years old) receiving CART immunotherapy for diffuse large B cell lymphoma (DLBCL), multiple myeloma (MM), mantle cell lymphoma (MCL), or follicular lymphoma (FL). We collected peripheral blood at two time points: i) pre-lymphodepletion therapy and ii) two weeks post CAR-T cell infusion. Peripheral blood mononuclear cells were isolated from blood via density gradient and T-cells isolated from PBMC with magnetic beads (negative selection). Telomere lengths are quantified from T-cells by using a highly sensitive technique called TeSLA (Telomere Shortest Length Assay) that allows absolute quantification of both the average telomere length and the lengths of critically short telomeres, which are believed to play a major role in promoting cell cycle arrest and T-cell exhaustion. Results: We identified 7 patients receiving CAR T cell therapy for hematological malignancies at University of Texas Southwestern Medical Center. The cohort included 7 patients, 2 patients with DLBCL and 1 patient with MCL receiving CD19 CAR-T Cell therapy and 4 patients with MM receiving BCMA CAR-T cell therapy. Median age of patient was 65 yrs. Median follow up was 273 days post CAR T-cell therapy with all patients being alive at last follow-up. Two patients experienced Grade I Cytokine release syndrome (CRS), two patients with Grade 2 CRS and one patient with Grade 2 ICANS. Our initial analysis shows that patients telomere lengths changes pre and post CAR T-cell infusion. Regarding change in critically short telomere (&lt;1.6kb); 6 out of 7 patients had reduction the shorter telomere from BL to post CAR-T. We are currently evaluating the effect of change in telomere length on outcomes. Conclusions: CAR T-cell therapy is a game-changer for hematological malignancies; however, disease still relapse. Understanding the mechanics of poor response or relapse after CAR T-cell therapy is critical in advancing the field. Initial results suggest T-cell telomere length are significantly affected during CAR T-cell manufacturing process and post infusion. These results are potentially important as telomere length can be utilized as a biomarker to predict CAR T-cell therapy outcomes. Figure 1 Figure 1. Disclosures Anderson: Celgene, BMS, Janssen, GSK, Karyopharm, Oncopeptides, Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Awan: Verastem: Consultancy; Incyte: Consultancy; Cardinal Health: Consultancy; Dava Oncology: Consultancy; BMS: Consultancy; ADCT therapeutics: Consultancy; Beigene: Consultancy; Celgene: Consultancy; Karyopharm: Consultancy; Pharmacyclics: Consultancy; MEI Pharma: Consultancy; Merck: Consultancy; Kite pharma: Consultancy; Gilead sciences: Consultancy; Johnson and Johnson: Consultancy; Abbvie: Consultancy; Janssen: Consultancy; Astrazeneca: Consultancy; Genentech: Consultancy. Madanat: Onc Live: Honoraria; Blue Print Pharmaceutical: Honoraria; Geron Pharmaceutical: Consultancy; Stem line pharmaceutical: Honoraria. Patel: Celgene-BMS: Membership on an entity's Board of Directors or advisory committees; PVI: Honoraria; Agios: Membership on an entity's Board of Directors or advisory committees. Sweetenham: EMA Wellness: Membership on an entity's Board of Directors or advisory committees. Kansagra: Alynylam, Celgene/BMS, Cota Health, GSK, Janssen, Karyopharm, Oncopeptide, Pfizer, Takeda, Sanofi: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Development and Evaluation of a Human Single Chain Variable Fragment (scFv) Derived Bcma Targeted CAR T Cell Vector Leads to a High Objective Response Rate in Patients with Advanced MM

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 742-742 ◽  
Author(s):  
Eric L Smith ◽  
Sham Mailankody ◽  
Arnab Ghosh ◽  
Reed Masakayan ◽  
Mette Staehr ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Employment Equity ◽  
Advisory Committees ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership

Abstract Patients with relapsed/refractory MM (RRMM) rarely obtain durable remissions with available therapies. Clinical use of BCMA targeted CAR T cell therapy was first reported in 12/2015 for RRMM, and based on small numbers, preliminary results appear promising. Given that host immune anti-murine CAR responses have limited the efficacy of repeat dosing (Turtle C. Sci Trans Med 2016), our goal was to develop a human BCMA targeted CAR T cell vector for clinical translation. We screened a human B cell derived scFv phage display library containing 6x1010 scFvs with BCMA expressing NIH 3T3 cells, and validated results on human MM cell lines. 57 unique and diverse BCMA specific scFvs were identified containing light and heavy chain CDR's each covering 6 subfamilies, with HCDR3 length ranges from 5-18 amino acids. 17 scFvs met stringent specificity criteria, and a diverse set was cloned into CAR vectors with either a CD28 or a 4-1BB co-stimulatory domain. Donor T cells transduced with BCMA targeted CAR vectors that conveyed particularly desirable properties over multiple in vitro assays, including: cytotoxicity on human MM cell lines at low E:T ratios (&gt;90% lysis, 1:1, 16h), robust proliferation after repeat antigen stimulation (up to 700 fold, stimulation q3-4d for 14d), and active cytokine profiling, were selected for in vivo studies using a marrow predominant human MM cell line model in NSG mice. A single IV injection of CAR T cells, either early (4d) or late (21d) after MM engraftment was evaluated. In both cases survival was increased when treated with BCMA targeted CAR T cells vs CD19 targeted CAR T cells (median OS at 60d NR vs 35d p&lt;0.05). Tumor and CAR T cells were imaged in vivo by taking advantage of luciferase constructs with different substrates. Results show rapid tumor clearance, peak (&gt;10,000 fold) CAR T expansion at day 6, followed by contraction of CAR T cells after MM clearance, confirming the efficacy of the anti-BCMA scFv/4-1BB containing construct. Co-culture with primary cells from a range of normal tissues did not activate CAR T cells as noted by a lack of IFN release. Co-culture of 293 cells expressing this scFv with those expressing a library of other TNFRSF or Ig receptor members demonstrated specific binding to BCMA. GLP toxicity studies in mice showed no unexpected adverse events. We generated a retroviral construct for clinical use including a truncated epithelial growth factor receptor (EGFRt) elimination gene: EGFRt/hBCMA-41BBz. Clinical investigation of this construct is underway in a dose escalation, single institution trial. Enrollment is completed on 2/4 planned dose levels (DL). On DL1 pts received cyclophosphamide conditioning (3g/m2 x1) and 72x106 mean CAR+ T cells. On DL2 pts received lower dose cyclophosphamide/fludarabine (300/30 mg/m2 x3) and 137x106 mean CAR+ T cells. All pts screened for BCMA expression by IHC were eligible. High risk cytogenetics were present in 4/6 pts. Median prior lines of therapy was 7; all pts had IMiD, PI, high dose melphalan, and CD38 directed therapies. With a data cut off of 7/20/17, 6 pts are evaluable for safety. There were no DLT's. At DL1, grade 1 CRS, not requiring intervention, occurred in 1/3 pts. At DL2, grade 1/2 CRS occurred in 2/3 pts; both received IL6R directed Tocilizumab (Toci) with near immediate resolution. In these 2 pts time to onset of fever was a mean 2d, Tmax was 39.4-41.1 C, peak CRP was 25-27mg/dl, peak IL6 level pre and post Toci were 558-632 and 3375-9071 pg/ml, respectively. Additional serum cytokines increased &gt;10 fold from baseline in both pts include: IFNg, GM CSF, Fractalkine, IL5, IL8, and IP10. Increases in ferritin were limited, and there were no cases of hypofibrinogenemia. There were no grade 3-5 CRS and no neurotoxicities or cerebral edema. No pts received steroids or Cetuximab. Median time to count recovery after neutropenia was 10d (range 6-15d). Objective responses by IMWG criteria after a single dose of CAR T cells were observed across both DLs. At DL1, of 3 pts, responses were 1 VGPR, 1 SD, and 1 pt treated with baseline Mspike 0.46, thus not evaluable by IMWG criteria, had &gt;50% reduction in Mspike, and normalization of K/L ratio. At DL2, 2/2 pts had objective responses with 1 PR and 1 VGPR (baseline 95% marrow involvement); 1 pt is too early to evaluate. As we are employing a human CAR, the study was designed to allow for an optional second dose in pts that do not reach CR. We have treated 2 pts with a second dose, and longer follow up data is pending. Figure 1 Figure 1. Disclosures Smith: Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: BCMA targeted CAR T cells, Research Funding. Almo: Cue Biopharma: Other: Founder, head of SABequity holder; Institute for Protein Innovation: Consultancy; AKIN GUMP STRAUSS HAUER & FELD LLP: Consultancy. Wang: Eureka Therapeutics Inc.: Employment, Equity Ownership. Xu: Eureka Therapeutics, Inc: Employment, Equity Ownership. Park: Amgen: Consultancy. Curran: Juno Therapeutics: Research Funding; Novartis: Consultancy. Dogan: Celgene: Consultancy; Peer Review Institute: Consultancy; Roche Pharmaceuticals: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees. Liu: Eureka Therpeutics Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Brentjens: Juno Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.

scholarly journals Evaluating Hematologist's Knowledge of CAR T-Cell Therapy in Hematologic Malignancies

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2269-2269
Author(s):  
Lauren Willis ◽  
Sara R. Fagerlie ◽  
Sattva S. Neelapu
Keyword(s):  
T Cell ◽  
Cell Therapy ◽  
Board Of Directors ◽  
Research Funding ◽  
Hematologic Malignancies ◽  
Advisory Committees ◽  
T Cell Therapy ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T

Abstract Background: The objective of this study was to assess current clinical practices of hematologist/oncologist (hem/onc) specialists related to chimeric antigen receptor (CAR) T-cell therapy in hematologic malignancies, in order to identify knowledge, competency, and practice gaps and barriers to optimal care. Methods: A continuing medical education (CME)-certified clinical practice assessment consisting of 25 multiple choice questions was developed to measure knowledge, skills, attitudes, and competence of hem/onc specialists regarding CAR T-cell therapy. The survey instrument was made available online to physicians without monetary compensation or charge. Respondent confidentiality was maintained, and responses were de-identified and aggregated prior to analyses. The activity launched on December 22, 2017 with global distribution, and participant responses are still being collected at the time of abstract submission. Results: At the time of this report there are 192 hem/onc activity participants, collection is on-going. Demographics are listed in Table 1 and levels of confidence and barriers to incorporating CAR T-cell therapy are listed in Table 2.Foundational KnowledgeSub-optimal knowledge was demonstrated in the area of CAR components, dosing, and FDA-approved indications.Over half (61%) could not correctly identify the components of a CAR construct (antigen-specific domain and the signaling domain).Almost half (45%) of the participants did not recognize that currently approved CAR T-cell therapies are dosed as a single infusion.25% demonstrated inaccurate knowledge by recommending patients wait 4 weeks after CAR T-cell infusion before driving.Over half (62%) of participants could not identify the FDA-approved indication for axicabtagene ciloleucel.Knowledge of Clinical Trial DataVery low awareness of efficacy data seen with various CAR T-cell products used to treat R/R B-cell ALL (ELIANA trial), R/R DLBCL (ZUMA-1, JULIET, TRANSCEND trials).Only 32% identified the correct CR/CRi rate seen with tisagenlecleucel in the ELIANA trial.Only 25% correctly identified the CR rate seen with axicabtagene ciloleucel in the ZUMA-1 trial.Only 32% demonstrated knowledge of the 6-month DFS rate for patients in the JULIET trial that had a CR at 3 months.Only 25% identified the association between the dose of JCAR017 and response rates from the TRANSCEND trial.Knowledge and Competence Managing Adverse EventsLack of competence recognizing and treating CAR T-cell associated adverse events such as cytokine release syndrome (CRS) and neurotoxicity.Almost half (44%) could not identify signs of CRS associated with CAR T-cell therapy and 43% lack knowledge that elevated serum C-reactive protein (CRP) is associated with the highest level of CRS (in patients with lymphoma receiving axicabtagene ciloleucel).41% could not identify that the mechanism of tocilizumab is to block IL-6 signaling.Over a third (35%) were unable to identify signs/symptoms/causes of neurotoxicity associated with CAR T-cell therapy.More than half of the learners (54%) could not identify the appropriate role of corticosteroid therapy after CAR T-cell administration in managing CRS and neurotoxicity. Conclusions: This activity found knowledge and competence deficits for hem/onc practitioners related to using CAR T-cell therapy for the treatment of patients with hematologic malignancies. Additionally, the activity demonstrated large gaps in confidence discussing CAR T-cell therapy with patients/families and managing adverse events. There is sub-optimal awareness of CAR T-cell foundational knowledge, clinical trial data, and recognition of common therapy related adverse events and management strategies. Additional education is needed to improve the knowledge, competence, and confidence of academic and community hem/onc specialists who care for patients with hematologic malignancies receiving CAR T-cell therapy as well as strategies for integrating novel agents into clinical practice. Disclosures Neelapu: Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Cellectis: Research Funding; Poseida: Research Funding; Merck: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta: Research Funding; Karus: Research Funding; Bristol-Myers Squibb: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Unum Therapeutics: Membership on an entity's Board of Directors or advisory committees; Kite/Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

scholarly journals Long-Term Remission of CLL Sustained By Pauciclonal Anti-CD19 Chimeric Antigen Receptor T (CTL019) Cell Clones

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 699-699 ◽  
Author(s):  
J. Joseph Melenhorst ◽  
David L. Porter ◽  
Lifeng Tian ◽  
Simon F Lacey ◽  
Christopher L Nobles ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Integration Site ◽  
Advisory Committees ◽  
Car T Cells ◽  
Car T Cell ◽  
Cell Clones ◽  
Car T

Abstract We recently demonstrated that sustained remission in 41 CLL patients treated with the CD19-specific, 4-1BB/CD3zeta-signaling chimeric antigen receptor (CAR19) T-cells correlated strongly with the expansion and persistence of the engineered T cells and that important pathways such as T cell exhaustion, glycolysis and T cell differentiation segregated responders from non-responders (Fraietta et al., 2018, Nature Medicine). We here report two advanced, chemotherapy-resistant CLL patients with the longest (7 years) follow-up on any trial of CART19 cells. Both patients had received five therapies before being treated at the University of Pennsylvania with autologous, murine CTL019 (tisagenlecleucel) cells for their CLL in 2010, receiving 1.1e9 and 1.4e7 CAR19+ T cells, respectively. Both patients have persistence of CAR-engineered T cells and both patients are still in remission as determined by flow cytometry and deep sequencing of IgH rearrangements for 5.5-7 years. Thus, the infused CAR-T cells have maintained these patients in deep molecular remission of their disease for the longest period of time that has been reported to date. To understand the fate of the infused CAR-T cells we determined the phenotype, function, and clonal nature of the persisting CTL019 cells. Flow cytometric CART19 cell analyses demonstrated that early during the anti-leukemia response, activated, HLA-DR-expressing CD8+ CAR-T cells rapidly expanded, followed by similarly activated CD4+ CAR-T cells. With tumor clearance the CAR-T cell population contracted, but an activated CD4+ CAR-T cell population was maintained and was still detectable at the last follow-up of 7 years. The CD8+ CAR-T cell pool remained present at low frequencies. Both populations had acquired and maintained an effector memory phenotype, a phenotype most consistent with active disease control. Furthermore, the analysis of the classical immune checkpoint inhibitory markers PD1, TIM3, LAG3, and CTLA4 showed that only PD1 was expressed from the earliest to the latest time point on >80% of all CAR-T cells, whereas LAG3 and TIM3 were expressed only early on but lost after tumor clearance. These data suggest that the initial tumor clearance was mediated by CD8+ CAR-T cells, but sustained by a CD4+ CAR-T cell population that still actively engages with target cells. To understand the clonal nature of these long-term persisting CAR-T cells we used two complementary methods: a) CAR T cells were sorted from post-infusion aliquots during the first two years for T cell receptor-beta deep-sequencing (TCR-seq); b) the CAR integration sites in the genome were sequenced in the infusion product and in circulating CAR-T cells. TCR-seq analysis of early post-infusion time points demonstrated that the circulating CAR-T cell populations consisted of hundreds to thousands of distinct clones which in patient 1 and 2 displayed clonal focusing by 21 and 1 month post-infusion, respectively, with some clones making up as much as 12% (patient 1) and 48% (patient 2) of the CAR-T cell repertoire. The analysis of clonotype sharing at the various time points via Morisita's overlap index analysis similarly showed repertoire stabilization late (21 months; patient 1) and early (1 month; patient 2) after infusion. Lastly, fate mapping of the infused CART19 cells via CAR integration site analysis in the infusion product until the latest time point indicated that the infusion products for both patients had a very diverse, non-clonal make-up, containing over 8,000 and 3,700 integration sites in patients 1 and 2, respectively. The higher degree of clonality in patient 2 but not 1 CAR-T cells as seen by TCR-seq was confirmed by integration site analysis, as was the sharing of CAR-T cell clones over time. Importantly, whereas the CAR integration site repertoire in patient 1 was diverse in the first two years, it stabilized and trended towards oligoclonality 21 months after infusion. Lastly, CAR integration site analysis revealed a high degree of clonal persistence, suggesting that tumor control and B cell aplasia were maintained by few, highly functional CD4+ CAR-T cell clones. In summary, we demonstrate that in both patients with the longest persistence of CAR-T cells reported thus far, early and late phases of the anti-CLL response are dominated by highly activated CD8+ and CD4+ CAR-T cells, respectively, largely comprised of a small number of persisting CD4+ CAR-T cell clones. Disclosures Melenhorst: Parker Institute for Cancer Immunotherapy: Research Funding; Incyte: Research Funding; Casi Pharmaceuticals: Consultancy; novartis: Patents & Royalties, Research Funding; Shanghai UNICAR Therapy, Inc: Consultancy. Porter:Genentech: Other: Spouse employment; Novartis: Other: Advisory board, Patents & Royalties, Research Funding; Kite Pharma: Other: Advisory board. Lacey:Novartis Pharmaceuticals Corporation: Research Funding; Tmunity: Research Funding; Novartis Pharmaceuticals Corporation: Patents & Royalties; Parker Foundation: Research Funding. Fraietta:Novartis: Patents & Royalties: WO/2015/157252, WO/2016/164580, WO/2017/049166. Frey:Novartis: Consultancy; Servier Consultancy: Consultancy. Young:Novartis: Patents & Royalties, Research Funding. Siegel:Novartis: Research Funding. June:Novartis Pharmaceutical Corporation: Patents & Royalties, Research Funding; Immune Design: Membership on an entity's Board of Directors or advisory committees; Tmunity Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Immune Design: Membership on an entity's Board of Directors or advisory committees; Celldex: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis Pharmaceutical Corporation: Patents & Royalties, Research Funding; Tmunity Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.

scholarly journals Single-Cell RNA Sequencing Identifies Expression Patterns Associated with Clinical Responses to Dual-Targeted CAR-T Cell Therapy

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 33-34
Author(s):  
Tyce Kearl ◽  
Ao Mei ◽  
Ryan Brown ◽  
Bryon Johnson ◽  
Dina Schneider ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Therapy ◽  
Research Funding ◽  
T Cell Therapy ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T Cell Therapy ◽  
Car T ◽  
Clinical Responses

INTRODUCTION: Chimeric Antigen Receptor (CAR)-T cell therapy is emerging as a powerful treatment for relapsed or refractory B cell lymphomas. However, a variety of escape mechanisms prevent CAR-T cell therapy from being more uniformly effective. To better understand mechanisms of CAR-T failure among patients treated with dual-targeted CAR-T cells, we performed single-cell RNA sequencing of samples from a Phase 1 trial (NCT03019055). The clinical trial used anti-CD20, anti-CD19 CAR-T cells for the treatment of relapsed/refractory B-cell non-Hodgkin Lymphoma. Clinical responses from this study are reported independently (Shah et al. in press in Nat Med). While robust clinical responses occurred, not all patients had similar outcomes. In single-antigen specific CAR-T cells, mechanisms of resistance include antigen down-regulation, phenotype switch, or PD-1 inhibition (Song et al. Int J Mol Sci 2019). However, very little is understood about the mechanisms of failure that are specific to dual-targeted CAR-T cells. Interestingly, loss of CD19 antigen was not observed in treatment failures in the study. METHODS: De-identified patient samples were obtained as peripheral blood mononuclear cells on the day of harvest ("pre" samples), at the peak of in vivo CAR-T cell expansion which varied from day 10 to day 21 after infusion ("peak" samples), and on day 28 post-infusion ("d28" samples). The CAR-T cell infusion product was obtained on day 14 of on-site manufacturing ("product" samples). All samples were cryopreserved and single cell preparation was performed with batched samples using 10X Genomics kits. Subsequent analysis was performed in R studio using the Seurat package (Butler et al. Nat Biotech 2018) with SingleR being used to identify cell types in an unbiased manner (Aran et al. Nat Immunol 2019). RESULTS: We found that distinct T cell clusters were similarly represented in the responder and non-responder samples. The patients' clinical responses did not depend on the level of CAR expression or the percentage of CAR+ cells in the infusion product. At day 28, however, there was a considerable decrease in the percentage of CAR+ cells in the responder samples possibly due to contracture of the CAR+ T cell compartment after successful clearance of antigen-positive cells. In all samples, the CAR-T cell population shifted from a CD4+ to a CD8+ T cell predominant population after infusion. We performed differentially-expressed gene analyses (DEG) of the total and CAR-T cells. In the pre samples, genes associated with T-cell stimulation and cell-mediated cytotoxicity were highly expressed in the responder samples. Since the responders had an effective anti-tumor response, we expected these pathways to also be enriched for in the peak samples; however, this was not the case. We hypothesize that differential expression of the above genes was masked due to homeostatic expansion of the T cells following conditioning chemotherapy. Based on the DEG results, we next interrogated specific genes associated with cytotoxicity, T cell co-stimulation, and checkpoint protein inhibition. Cytotoxicity-associated genes were highly expressed among responder CD8+ T cells in the pre samples, but not in the other samples (Figure 1). Few differences were seen in specific co-stimulatory and checkpoint inhibitor genes at any timepoint in the T cell clusters. We performed gene set enrichment analyses (GSEA). Gene sets representing TCR, IFN-gamma, and PD-1 signaling were significantly increased in the pre samples of the responders but not at later time points or in the infusion products. DISCUSSION: We found a correlation between expression of genes associated with T cell stimulation and cytotoxicity in pre-treatment patient samples and subsequent response to CAR-T cell therapy. This demonstrates that the existing transcriptome of T cells prior to CAR transduction critically shapes anti-tumor responses. Further work will discover biomarkers that can be used to select patients expected to have better clinical outcomes. Figure 1 Disclosures Johnson: Miltenyi Biotec: Research Funding; Cell Vault: Research Funding. Schneider:Lentigen, a Miltenyi Biotec Company: Current Employment, Patents & Royalties. Dropulic:Lentigen, a Miltenyi Biotec Company: Current Employment, Patents & Royalties: CAR-T immunotherapy. Hari:BMS: Consultancy; Amgen: Consultancy; GSK: Consultancy; Janssen: Consultancy; Incyte Corporation: Consultancy; Takeda: Consultancy. Shah:Incyte: Consultancy; Cell Vault: Research Funding; Lily: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria; Verastim: Consultancy; TG Therapeutics: Consultancy; Celgene: Consultancy, Honoraria; Miltenyi Biotec: Honoraria, Research Funding.

scholarly journals Efficacy and Toxicity of JCAR014 in Combination with Durvalumab for the Treatment of Patients with Relapsed/Refractory Aggressive B-Cell Non-Hodgkin Lymphoma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1680-1680 ◽  
Author(s):  
Alexandre V. Hirayama ◽  
Jordan Gauthier ◽  
Kevin A. Hay ◽  
Alyssa Sheih ◽  
Sindhu Cherian ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Advisory Committees ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Group 2

Abstract Introduction Autologous T cells engineered to express a CD19-specific chimeric antigen receptor (CAR) have shown high overall response rates (ORR) in otherwise treatment-refractory CD19+ B-cell non-Hodgkin lymphoma (NHL); however, not all patients (pts) achieve complete remission (CR). PD-L1 expression on tumor cells and/or other tissues could impair the function of PD-1+ CAR-T cells and the efficacy of CD19 CAR-T cell immunotherapy. PD-1 pathway blockade may enhance the function and antitumor activity of CD19 CAR-T cells. Here we report preliminary data from a phase 1 dose-finding study (NCT02706405) of the safety and feasibility of combination therapy with JCAR014 CD19-specific 4-1BB-costimulated CAR-T cells and escalating doses of durvalumab, an anti-PD-L1 monoclonal antibody, in adults with relapsed/refractory aggressive B-cell NHL. Methods Pts are treated in one of two groups. All pts receive lymphodepletion chemotherapy with cyclophosphamide and fludarabine followed by infusion of JCAR014. Pts in group 1 receive the first infusion of durvalumab (225 mg, 750 mg, or 1500 mg) 21-28 days after treatment with JCAR014. Pts in group 2 receive the first dose of durvalumab (7.5 mg, 22.5 mg, 75 mg, 225 mg, 750 mg, or 1500 mg) 1 day prior to JCAR014 infusion. Up to 10 doses of durvalumab are administered after JCAR014 at the highest identified safe dose at 4-week intervals until toxicity or disease progression. We evaluated the safety, tolerability, and efficacy of the combination therapy and the pharmacokinetic profile of JCAR014 after infusion. Adverse events were graded using the Common Terminology Criteria for Adverse Events (CTCAE) v4.03, with the exception of cytokine release syndrome (CRS), which was graded according to consensus criteria (Lee, Blood 2014). Positron emission tomography/computed tomography was performed approximately 1, 2, 4, 6, 9, and 12 months after JCAR014 infusion and the best anti-tumor response was reported according to the Lugano criteria (Cheson, JCO 2014). Results Patient characteristics are shown in Table 1. Fifteen pts have been treated, including 6 in group 1 who received post-JCAR014 durvalumab doses of 225 mg (n = 3) and 750 mg (n = 3), and 9 in group 2 who received pre-JCAR014 durvalumab doses of 7.5 mg (n = 1), 22.5 mg (n = 1), 75 mg (n = 3), or 225 mg (n = 4). Durvalumab dose escalation is ongoing. JCAR014 manufacturing was successful for all pts. All pts received 2 x 106 JCAR014 CAR-T cells/kg, except the first 2 pts treated on the study who received 7 x 105 CAR-T cells/kg. Of the 13 pts who received JCAR014 at 2 x 106 CAR-T cells/kg, 5 pts (38%) developed CRS (2 grade 1, 2 grade 2, and 1 grade 4) and one (8%) developed grade 1 neurotoxicity. CRS and/or neurotoxicity occurred within 4 weeks of JCAR014 infusion, and were not observed when durvalumab was administered after JCAR014. With the exception of B cell aplasia, no autoimmune adverse events were observed. Twelve of 13 pts who received 2 x 106 CAR-T cells/kg were evaluable for response. One patient, who had grade 4 CRS and biopsy evidence of extensive CAR-T cell infiltration into persistent sites of disease, elected to receive hospice care and died on day 32 after JCAR014 infusion without full response evaluation. The overall response rate was 50% (5 CR, 42%; 1 PR, 8%). Of the 5 pts who achieved CR, 3 were in CR at the first restaging after JCAR014 and 2 subsequently converted to CR after the first post-JCAR014 durvalumab infusion. Only one patient who achieved CR has relapsed (median follow-up 10.6 months, range 3.7-11.8). Continued stable disease or evidence of regression was seen in 4 of 6 (67%) initially non-responding pts who continued durvalumab therapy (median 5 doses, range 1-6). CAR-T cell counts expanded in the peripheral blood within 14 days of JCAR014 infusion in all pts. Higher peak and day 28 CAR-T cell copy numbers in blood by qPCR were observed in responding pts. CAR-T cells were detected for a median of 5.1 months (range, 1.7 to 9.1 months) in responding pts. In vivo re-accumulation of CAR-T cells after the first post-JCAR014 durvalumab dose was observed in the blood of two patients in group 2. Conclusion The combination of JCAR014 with durvalumab for the treatment of adult pts with aggressive B-cell NHL appears safe; however, dose escalation is ongoing. Complete responses were observed both at initial restaging after JCAR014 infusion, and also subsequently in pts continuing durvalumab therapy after initially failing to achieve CR. Disclosures Hirayama: DAVA Oncology: Honoraria. Hay:DAVA Oncology: Honoraria. Till:Mustang Bio: Patents & Royalties, Research Funding. Kiem:Homology Medicine: Consultancy; Magenta: Consultancy; Rocket Pharmaceuticals: Consultancy. Shadman:Verastem: Consultancy; Beigene: Research Funding; Mustang Biopharma: Research Funding; Gilead Sciences: Research Funding; TG Therapeutics: Research Funding; AbbVie: Consultancy; Genentech: Research Funding; Pharmacyclics: Research Funding; Celgene: Research Funding; Qilu Puget Sound Biotherapeutics: Consultancy; Genentech: Consultancy; AstraZeneca: Consultancy; Acerta Pharma: Research Funding. Cassaday:Jazz Pharmaceuticals: Consultancy; Amgen: Consultancy, Research Funding; Merck: Research Funding; Seattle Genetics: Other: Spouse Employment, Research Funding; Pfizer: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy; Kite Pharma: Research Funding; Incyte: Research Funding. Acharya:Juno Therapeutics: Research Funding; Teva: Honoraria. Riddell:Cell Medica: Membership on an entity's Board of Directors or advisory committees; Juno Therapeutics: Equity Ownership, Patents & Royalties, Research Funding; Adaptive Biotechnologies: Consultancy; NOHLA: Consultancy. Maloney:Roche/Genentech: Honoraria; Juno Therapeutics: Research Funding; Janssen Scientific Affairs: Honoraria; GlaxoSmithKline: Research Funding; Seattle Genetics: Honoraria. Turtle:Precision Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Consultancy; Bluebird Bio: Consultancy; Gilead: Consultancy; Nektar Therapeutics: Consultancy, Research Funding; Eureka Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Juno Therapeutics / Celgene: Consultancy, Patents & Royalties, Research Funding; Caribou Biosciences: Consultancy; Aptevo: Consultancy.

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