scholarly journals Developing a Novel Anti-Bcma CAR-T for Relapsed or Refractory Multiple Myeloma

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 50-50 ◽  
Author(s):  
Xin Yao ◽  
Shigui Zhu ◽  
Jiaqi Huang ◽  
Xiaoyan Qu ◽  
Judy Zhu ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Multiple Myeloma ◽  
T Cells ◽  
Tumor Cells ◽  
Human Monoclonal Antibody ◽  
Employment Equity ◽  
Early Clinical Trial ◽  
Car T Cells ◽  
Car T ◽  
Equity Ownership

CBMG has developed C-CAR088, a novel chimeric antigen receptor (CAR)-T cell therapy targeting BCMA, which is specifically and highly expressed on multiple myeloma cells. C-CAR088 is designed to improve efficacy through increasing the specificity and reducing immunogenicity by fusing a scFv from high-affinity human monoclonal antibody to a CD3ζ/4-1BB signaling domain. In preclinical study, the human T cells transduced with the lentiviral vector encoding C-CAR088 exhibited specific functions in vitro including CAR-T proliferation, cytokine production, cytotoxicity to BCMA positive tumor cells. C-CAR088 cells were not activated by soluble BCMA protein and MM patient serums. However, they can eradicate BCMA positive tumor cells in vivo including BMCA positive multiple myeloma tumor model RPMI-8226. C-CAR088 is manufactured in a serum free, automated and digital, closed system which produce CAR-T cells with stable and high percentage of Tcm phenotype. C-CAR088 showed a very good dose dependent tumor inhibition effect and survival benefit in animal studies. A Phase 1, 3+3 dose escalation trial is being conducted in patients with r/r MM (≥ 3 prior lines, having received treatment and proteasome inhibitors (PI) and IMiD or double refractory) to assess the safety and efficacy of C-CAR088 (NCT03815383). Patients are apheresed to harvest T cells. C-CAR088 is then manufactured and administered to patients as a single intravenous dose after a standard 3-day cyclophosphamide/fludarabine conditioning regimen. As of July 5, 2019 cutoff date, 3 patients have been treated with C-CAR088 at the dose of 1.0 x 106 CAR-T cells/kg. Patients were heavily pre-treated (7 prior lines of therapy), and all failed IMiDs and proteasome inhibitor therapies. After C-CAR088 treatment, all three patients showed clinical improvement as early as two weeks post treatment. Furthermore, C-CAR088 proliferation & expansion in the peripheral blood correlated with the decrease of tumor burden. Two patients reached VGPR at 4 weeks and 8 weeks respectively, and the third patient reached PR as early as 2 weeks post C-CAR088 infusion. C-CAR088 treatment was well tolerated, no dose-limiting toxicities (DLTs), reversible Grade 1~2 CRS observed. In conclusion, early clinical trial results in patients with r/r MM for C-CAR088 support preclinical findings that the drug shows promising efficacy and manageable safety profile.The very early clinical efficacy signal at low, suboptimal dose is encouraging and compares favorably to many other anti-BCMA CAR-T products at similar dose. The promising trend needs to be confirmed by the ongoing clinical trial. Disclosures Yao: Cellular Biomedicine Group Inc: Employment, Equity Ownership. Zhu:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Huang:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Zhu:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Wei:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Lan:Cellular Biomedicine Group Inc: Employment, Equity Ownership. LV:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Wu:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Wang:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Yang:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Zheng:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Zhao:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Zhang:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Chen:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Li:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Ren:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Zhang:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Humphries:Cellular Biomedicine Group Inc: Employment, Equity Ownership. Yao:Cellular Biomedicine Group Inc: Employment, Equity Ownership.

scholarly journals Preclinical Development of CTX120, an Allogeneic CAR-T Cell Targeting Bcma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1921-1921 ◽  
Author(s):  
Henia Dar ◽  
Daniel Henderson ◽  
Zinkal Padalia ◽  
Ashley Porras ◽  
Dakai Mu ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
T Cell ◽  
Cell Targeting ◽  
Employment Equity ◽  
Term Survival ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership

Abstract Autologous CAR-T cells targeting BCMA have induced robust and durable responses in patients with relapsed/refractory multiple myeloma. However, autologous cell therapies face several challenges which will likely limit the number of patients that will have access to these therapies. These limitations include manufacturing failure rates, wait time and supply constraints in addition to other factors such as reimbursement. Allogeneic CAR-T cells can potentially overcome these access challenges, and may have several other advantages over autologous therapies. Allogeneic CAR-T cells are derived from robust healthy donor T cells through a batch manufacturing process, which may result in a highly consistent product with greater potency and enable better safety management. Here we show further development and preclinical data for CTX120, an allogeneic "off the shelf" CAR-T cell targeting BCMA. CTX120 is produced using the CRISPR/Cas9 system to eliminate TCR and MHC class I, coupled with specific insertion of the CAR at the TRAC locus. CTX120 shows consistent and high percent CAR expression from this controlled insertion and exhibits target-specific cytotoxicity and cytokine secretion in response to BCMA positive cell lines. CTX120 CAR-T cells retain their cytotoxic capacity over multiple in vitro re-challenges, demonstrating durable potency and lack of exhaustion. In mouse models of multiple myeloma, CTX120 showed typical CAR-T persistence and eliminated tumors completely, resulting in long-term survival as compared to untreated animals. These data support the ongoing development of CTX120 for treatment of patients with multiple myeloma and further demonstrate the potential for our CRISPR/Cas9 engineered allogeneic CAR-T platform to generate potent CAR-T cells targeting different tumor antigens. Disclosures Dar: CRISPR Therapeutics: Employment, Equity Ownership. Henderson:CRISPR Therapeutics: Employment, Equity Ownership. Padalia:CRISPR Therapeutics: Employment, Equity Ownership. Porras:CRISPR Therapeutics: Employment, Equity Ownership. Mu:CRISPR Therapeutics: Employment, Equity Ownership. Kyungah:CRISPR Therapeutics: Employment, Equity Ownership. Police:CRISPR Therapeutics: Employment, Equity Ownership. Kalaitzidis:CRISPR Therapeutics: Employment, Equity Ownership. Terrett:CRISPR Therapeutics: Employment, Equity Ownership. Sagert:CRISPR Therapeutics: Employment, Equity Ownership.

scholarly journals Durable Clinical Responses in Heavily Pretreated Patients with Relapsed/Refractory Multiple Myeloma: Updated Results from a Multicenter Study of bb2121 Anti-Bcma CAR T Cell Therapy

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 740-740 ◽  
Author(s):  
Jesus G. Berdeja ◽  
Yi Lin ◽  
Noopur Raje ◽  
Nikhil Munshi ◽  
David Siegel ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
T Cell ◽  
Research Funding ◽  
Employment Equity ◽  
Car T Cells ◽  
Car T ◽  
Clinical Responses ◽  
Equity Ownership ◽  
Dose Levels

Abstract Introduction: Chimeric antigen receptor (CAR) T cell therapies have demonstrated robust and sustained clinical responses in several hematologic malignancies. Data suggest that achieving acceptable benefit:risk profiles depends on several factors, including the specificity of the antigen target and characteristics of the CAR itself, including on-target, off-tumor activity.To test the safety and efficacy of CAR T cells in relapsed and/or refractory multiple myeloma (RRMM), we have designed a second-generation CAR construct targeting B cell maturation antigen (BCMA) to redirect T cells to MM cells. BCMA is a member of the tumor necrosis factor superfamily that is expressed primarily by malignant myeloma cells, plasma cells, and some mature B cells. bb2121 consists of autologous T cells transduced with a lentiviral vector encoding a novel CAR incorporating an anti-BCMA scFv, a 4-1BB costimulatory motif and a CD3-zeta T cell activation domain. Methods: CRB-401 (NCT02658929) is a multi-center phase 1 dose escalation trial of bb2121 in patients with RRMM who have received ≥ 3 prior regimens, including a proteasome inhibitor and an immunomodulatory agent, or are double-refractory, and have ≥ 50% BCMA expression on malignant cells. Peripheral blood mononuclear cells are collected via leukapheresis and shipped to a central facility for transduction, expansion, and release testing prior to being returned to the site for infusion. Patients undergo lymphodepletion with fludarabine (30 mg/m2) and cyclophosphamide (300 mg/m2) daily for 3 days then receive 1 infusion of bb2121. The study follows a standard 3+3 design with planned dose levels of 50, 150, 450, 800, and 1,200 x 106 CAR+ T cells. The primary outcome measure is incidence of adverse events (AEs), including dose-limiting toxicities (DLTs). Additional outcome measures were quality and duration of clinical response assessed according to the IMWG Uniform Response Criteria for Multiple Myeloma, evaluation of minimal residual disease (MRD), overall and progression-free survival, quantification of bb2121 in blood, and quantification of circulating soluble BCMA over time. Results: Asof May 4, 2017, 21 patients (median 58 [37 to 74] years old) with a median of 5 (1 to 16) years since MM diagnosis, had been infused with bb2121, and 18 patients were evaluable for initial (1-month) clinical response. Patients had a median of 7 prior lines of therapy (range 3 to 14), all with prior autologous stem cell transplant; 67% had high-risk cytogenetics. Fifteen of 21 (71%) had prior exposure to, and 6 of 21 (29%) were refractory to 5 prior therapies (Bort/Len/Car/Pom/Dara). Median follow-up after bb2121 infusion was 15.4 weeks (range 1.4 to 54.4 weeks). As of data cut-off, no DLTs and no treatment-emergent Grade 3 or higher neurotoxicities similar to those reported in other CAR T clinical studies had been observed. Cytokine release syndrome (CRS), primarily Grade 1 or 2, was reported in 15 of 21 (71%) patients: 2 patients had Grade 3 CRS that resolved in 24 hours and 4 patients received tocilizumab, 1 with steroids, to manage CRS. CRS was more common in the higher dose groups but did not appear related to tumor burden. One death on study, due to cardiopulmonary arrest more than 4 months after bb2121 infusion in a patient with an extensive cardiac history, was observed while the patient was in sCR and was assessed as unrelated to bb2121. The overall response rate (ORR) was 89% and increased to 100% for patients treated with doses of 150 x 106 CAR+ T cells or higher. No patients treated with doses of 150 x 106 CAR+ T cells or higher had disease progression, with time since bb2121 between 8 and 54 weeks (Table 1). MRD negative results were obtained in all 4 patients evaluable for analysis. CAR+ T cell expansion has been demonstrated consistently and 3 of 5 patients evaluable for CAR+ cells at 6 months had detectable vector copies. A further 5 months of follow up on reported results and initial data from additional patients will be presented. Conclusions: bb2121 shows promising efficacy at dose levels above 50 x 106 CAR+ T cells, with manageable CRS and no DLTs to date. ORR was 100% at these dose levels with 8 ongoing clinical responses at 6 months and 1 patient demonstrating a sustained response beyond one year. These initial data support the potential of CAR T therapy with bb2121 as a new treatment paradigm in RRMM. CT.gov study NCT02658929, sponsored by bluebird bio and Celgene Disclosures Berdeja: Teva: Research Funding; Janssen: Research Funding; Novartis: Research Funding; Abbvie: Research Funding; Celgene: Research Funding; BMS: Research Funding; Takeda: Research Funding; Vivolux: Research Funding; Amgen: Research Funding; Constellation: Research Funding; Bluebird: Research Funding; Curis: Research Funding. Siegel: Celgene, Takeda, Amgen Inc, Novartis and BMS: Consultancy, Speakers Bureau; Merck: Consultancy. Jagannath: MMRF: Speakers Bureau; Bristol-Meyers Squibb: Consultancy; Merck: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Medicom: Speakers Bureau. Turka: bluebird bio: Employment, Equity Ownership. Lam: bluebird bio: Employment, Equity Ownership. Hege: Celgene Corporation: Employment, Equity Ownership. Morgan: bluebird bio: Employment, Equity Ownership, Patents & Royalties. Quigley: bluebird bio: Employment, Equity Ownership, Patents & Royalties. Kochenderfer: Bluebird bio: Research Funding; N/A: Patents & Royalties: I have multiple patents in the CAR field.; Kite Pharma: Research Funding.

scholarly journals Low Dose of Human scFv-Derived BCMA-Targeted CAR-T Cells Achieved Fast Response and High Complete Remission in Patients with Relapsed/Refractory Multiple Myeloma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 960-960 ◽  
Author(s):  
Songfu Jiang ◽  
Jie Jin ◽  
Siguo Hao ◽  
Min Yang ◽  
Linjun Chen ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
Single Dose ◽  
Employment Equity ◽  
Car T Cells ◽  
Car T ◽  
Dose Infusion ◽  
Human Scfv ◽  
Equity Ownership ◽  
Grade 3

Abstract Introduction: B Cell Mature Antigen (BCMA)-targeted chimeric antigen receptor T (CAR-T) cell therapy emerges as promising treatment for patients with relapse/refractory multiple myeloma (RRMM). Previous studies indicate patients who receive high-dose CAR-T cells may achieve better remission but have worse adverse events, like cytokine release syndrome (CRS). To solve this dilemma, we have developed novel autologous CAR-T therapeutics CT053 that are genetically modified T cells comprising an extracellular anti-BCMA human scFv and an intracellular 4-1BB costimulatory motif connected to a CD3-zeta T cell activation domain. Methods: A multi-center investigator-initiated clinical study is designed to evaluate CT053 in patients with RRMM who have failed in the prior treatment with ≥2 regimens, including a proteasome inhibitor, an immunomodulatory agent, and anti-CD38 monoclonal antibody. All patients have ≥50% BCMA expression on malignant cells. Patients are subjected to the lymphodepletion with 20-25 mg/m2 fludarabine and 300-500 mg/m2 cyclophosphamide daily for 2-4 days prior to receiving single-dose infusion of CT053 CAR-T cells. In case of progressive disease, patient may be dosed again on basis of investigators' evaluation of the disease status, BCMA expression and CAR-T persistence. Most enrolled patients received a single dose of 1.5 x 108 cells, except for 1 patient who received 0.5 x 108 cells and 1 patient who was infused with 1.8 x 108 cells. The primary outcome measure is incidence of adverse events (AEs), including dose-limiting toxicities (DLTs) and CAR T related AEs. Additional outcome measures include clinical response assessed according to the IMWG Uniform Response Criteria for Multiple Myeloma, overall and progression-free survival, pharmacokinetics and pharmacodynamic of CT053. Results: The study was performed in compliance with the declaration of Helsinki. As of the data cut-off date (July 10th, 2018), 16 patients (median 55 [39 to 67] years old) with a median of 3.9 (0.4 to 16.7) years since MM diagnosis, were infused with CT053. Patients had a median of 4 prior different regimens (range 2 to 10), and 56% (9/16) patients received prior autologous or allogeneic stem cell transplant. Among 16 patients, no neurotoxicity and no dose-limiting toxicities (DLT) were observed. The most common grade≥3 CAR-T related AEs were 3 thrombocytopenia (19%), 3 leukopenia (19%), 2 anemia (13%), 2 neutropenia (13%), 2 fever (13%) (Figure 1A). CRS was reported in 3 patients, including 1 Grade 3, 1 Grade 2 and 1 Grade 1, who had rapid recovery after Tocilizumab administration. 13/16 patients were eligible for initial evaluation of early clinical response with a median observation period of 8 (4 to 36) weeks. Overall response rate (ORR) in 13/13 patients was 100% post treatment. 12/13 patients (92%) quickly achieved partial response (4 PR), very good PR (6 VGPR), and complete response (2 CR) within 4 weeks post single-dose infusion (Figure 1B). 5/12 patients (42%) who were dosed at ≥1.5 x 108 CT053 CAR-T cells obtained CR at a median of 8 weeks post treatment. Durable responses from 4 weeks towards the data cut-off date were found in 12/13 patients (92%). One relapse from VGPR by the Week 12 was reported in a patient who had aggressive RRMM at enrollment and received the reduced dose of lymphodepletion regimen at 19 mg/m2 fludarabine and 192 mg/m2 cyclophosphamide for 2 days prior to CT053 infusion. Because positive BCMA expression on malignant cells was verified at relapse, the patient was re-dosed with CT053 at the Week 16 and subjected to the further evaluation. All patients had detectable CAR-T expansion from Day 3 post CT053 infusion. Expansion peaks were found on Day 7 (5/13), Day 14 (6/13) and Day 21 (2/13). 11/13 patients had notable persistence of CT053 CAR-T cells up to 4-6 months. The only relapsed patient had the lowest CAR-T expansion peak among 13 patients, indicating the potential correlation between CAR-T expansion and response outcome. Conclusions: Data from this early-stage clinical study showed the unparalleled safety and efficacy of CT053 CAR-T cells. Major AEs were transient, manageable, and reversible. 100% ORR in 13/13 evaluable patients were reported post single-dose infusion of 0.5~1.8 x 108 cells. 5/12 patients who were dosed at ≥1.5 x 108 CAR-T cells rapidly achieved durable CR at median of 8 weeks, suggesting CT053 could be developed as competitive therapeutics to treat patients with RRMM. Disclosures Ruan: CARsgen Therapeutics: Employment. Xiao:CARsgen Therapeutics: Employment, Equity Ownership. Wang:CARsgen Therapeutics: Employment, Equity Ownership. Li:CARsgen Therapeutics: Employment, Equity Ownership.

scholarly journals Response to Bcma CAR-T Cells Correlates with Pretreatment Target Antigen Density and Is Improved By Small Molecule Inhibition of Gamma Secretase

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1856-1856 ◽  
Author(s):  
Damian J. Green ◽  
Margot Pont ◽  
Andrew J. Cowan ◽  
Gabriel O Cole ◽  
Blythe Duke Sather ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Cells ◽  
Research Funding ◽  
Gamma Secretase ◽  
Employment Equity ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership

Introduction: The adoptive transfer of B-Cell Maturation Antigen (BCMA) chimeric antigen receptor (CAR) T cells is demonstrating early promise in multiple myeloma [MM], however durable responses remain elusive and most studies report >50% of patients relapsing within 18 months of receiving CAR-T cell therapy. The mechanism of relapse is likely the consequence of multiple factors including the variable distribution of BCMA on tumor cells, allowing cells with low antigen density to escape. Initial target density, receptor downregulation and the emergence of antigen loss variants have all been implicated in relapse following CAR-T cells directed against CD22 and CD19. Reduced or absent BCMA expression may similarly be linked to relapse in MM. We have previously demonstrated that BCMA cleavage by the γ-secretase complex reduces ligand density for CAR-T cell recognition, and that a small molecule γ-secretase inhibitor (GSI) markedly increases surface BCMA levels in a dose-dependent fashion while improving CAR-T cell recognition in preclinical models. Methods and Results: In a phase I first-in-human study (NCT03338972) employing a CAR-T cell construct encoding a fully human BCMA scFv and 4-1BB/CD3z, rapid and deep objective responses at CAR-T cell doses starting at 5 x 107 have been observed. All patients had bone marrow (BM) involvement at baseline (mean 42.5 % CD138+ by IHC) and 14/15 had no detectable disease in the BM 28 days after therapy. One patient with comparatively very low BCMA expression (BCMA antibody binding capacity [ABC; QuantiBRITE] = 269; 16.9% of the malignant plasma cells (PCs) BCMA+ by flow cytometry) was the only subject with persistent tumor cells in the BM 28 days after therapy. Despite complete BM responses in all remaining patients, late relapses have occurred. Differences in the BCMA expression level on tumor cells prior to CAR-T cells between long term responders and those with relapse are evident. Among the 12 subjects with at least 3 months of follow up, those remaining in remission (median 12 months, range 3-16; data cut off 7/15/19) demonstrated a median pre-treatment BCMA ABC of 1761 (range 781-2922, n=5), in contrast patients with relapse (mean of 7.3 months, range 2-12) had a median pre-treatment BCMA ABC of 920 (range 260-1540, n=7). Six patients with a pretreatment mean ABC of 919 (range 260-1540) had BM evaluable for BCMA expression at relapse and the mean ABC decreased to 304 (range 121-519). The percent PCs expressing BCMA decreased from 77.5% (range 13 - 99.8) to 30% (range 10.4-60.4). The impact of gamma secretase inhibition on BCMA expression was assessed on BM cells obtained from a patient relapsing after BCMA CAR-T cells. At relapse a 9.5-fold decrease in ABC from baseline was observed. The cells were cultured for 5 hours in the presence of GSI (JSMD194) at a concentration of 1mM, which is readily achievable by oral administration. A significant increase in BCMA antigen expression was observed (ABC=917). The impact of modulating BCMA expression on tumor cells by concurrently administering an oral GSI with CAR-T cells is being explored in a phase one clinical trial (NCT03502577). In this setting, the GSI has increased BCMA expression when low level residual BCMA was observed following relapse after prior BCMA therapy failure. Two patients have been evaluated for response to an JSMD194 after failing other BCMA targeted agents. One received a prior BCMA CAR-T cell product and after relapse demonstrated a BCMA ABC of 769. Target expression increased in this patient almost nine-fold to 6828 (ABC) after three oral doses of JSMD194. A second patient had a BCMA ABC of 666 after failing a BCMA bispecific T cell engager. BCMA density increased over 14-fold to 9583 after GSI. Comprehensive data from the combination GSI and BCMA CAR-T cell trial are being reported separately. Conclusion: Pretreatment BCMA target density quantified with a uniform flow cytometry method of measurement and performed on all patients enrolled on a single center BCMA CAR-T cell clinical trial is associated with the durability of response. Further, BCMA expression can be significantly increased following GSI exposure in patients evidencing low BCMA ABC at baseline or when downregulation is the consequence of prior BCMA targeting therapy. The capacity for GSIs to increase BCMA target density and decrease soluble BCMA levels is a promising approach to be exploited in clinical trials. Disclosures Green: Juno Therapeutics: Consultancy, Patents & Royalties, Research Funding; Celgene: Consultancy; GSK: Consultancy; Seattle Genetics: Research Funding; Cellectar: Research Funding. Pont:Fred Hutchinson Cancer Research Center: Other: Inventor on a patent. Cowan:Sanofi: Consultancy; Juno: Research Funding; Abbvie: Research Funding; Janssen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Cellectar: Consultancy. Sather:Lyell Immunopharma: Employment, Equity Ownership. Blake:Celgene: Employment, Equity Ownership. Works:Celgene: Employment, Equity Ownership. Maloney:Juno Therapeutics: Honoraria, Patents & Royalties: patients pending , Research Funding; A2 Biotherapeutics: Honoraria, Other: Stock options ; BioLine RX, Gilead,Genentech,Novartis: Honoraria; Celgene,Kite Pharma: Honoraria, Research Funding. Riddell:Juno Therapeutics: Equity Ownership, Patents & Royalties, Research Funding; Adaptive Biotechnologies: Consultancy; Lyell Immunopharma: Equity Ownership, Patents & Royalties, Research Funding. OffLabel Disclosure: Oral Gamma Secretase Inhibitor. Purpose is to increase expression of B Cell Maturation Antigen

scholarly journals JCARH125, Anti-BCMA CAR T-cell Therapy for Relapsed/Refractory Multiple Myeloma: Initial Proof of Concept Results from a Phase 1/2 Multicenter Study (EVOLVE)

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 957-957 ◽  
Author(s):  
Sham Mailankody ◽  
Myo Htut ◽  
Kelvin P. Lee ◽  
William Bensinger ◽  
Todd Devries ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
Research Funding ◽  
Phase 1 ◽  
Employment Equity ◽  
Car T Cells ◽  
Car T ◽  
Equity Ownership ◽  
Grade 3

Abstract Introduction: B-cell maturation antigen (BCMA) is expressed on malignant plasma cells and is an attractive therapeutic target for multiple myeloma. BCMA CAR T-cells, antibody drug conjugates and bispecific T-cell engagers have demonstrated substantial preclinical and clinical activity to date. JCARH125 is a BCMA-targeting CAR T product containing a lentiviral CAR construct with a fully human scFv, optimized spacer, 4-1BB co-stimulatory and CD3z activation domains. The construct has shown minimal tonic signaling and lack of inhibition by soluble BCMA. JCARH125 is generated using a manufacturing process developed to optimize various aspects, including increased consistency of cell health, in the drug product. Methods: EVOLVE (NCT03430011) is a multi-center, phase 1/2 trial of JCARH125 in patients with relapsed and/or refractory multiple myeloma, who have received 3 or more prior regimens, which must include autologous stem cell transplant, a proteasome inhibitor, immunomodulatory drug and an anti-CD38 monoclonal antibody, unless not a candidate (i.e. contraindicated) to receive one or more of the above treatments. Lymphodepleting chemotherapy (LDC) consisting of 3 days of fludarabine (30 mg/m2) and cyclophosphamide (300 mg/m2) is given 2 to 7 days prior to JCARH125 infusion. A single dose of JCARH125 is given on day 1. Dose escalation is determined using the modified toxicity probability interval 2 (mTPI-2). A minimum of 3 patients are evaluated at each dose level (DL). The first 2 DLs evaluated were 50 and 150x 106 CAR+ T cells. Additional DLs are planned, followed by an expansion at the recommended phase 2 dose (RP2D). The primary objectives of the phase 1 portion are safety and identifying a RP2D. Results: At the time of the July 12, 2018 data analysis, 19 patients have been enrolled (i.e. apheresed) and 13 patients dosed with JCARH125. Only one patient was unable to receive JCARH125, due to sepsis after LDC, leading to death before JCARH125 administration. Eight patients were evaluable for safety (≥ 1 mo follow-up). (n = 5 DL1; n = 3 DL2). Three patients (all from DL1) were evaluable for confirmed response (≥ 2 mo follow-up) per International Myeloma Working Group (IMWG) criteria. Data reported here are from these initial 8 patients. Median follow-up is 5 weeks (range 4 - 13 weeks). Median age is 53 years (range 36 - 66) with a median time from diagnosis of 4 years (range 2 - 12). Patients had received a median of 10 prior regimens (range 4 - 15). Of these 8 patients, 4 (50%) were refractory (no response or progression within 60 days of last therapy) to bortezomib, carfilzomib, lenalidomide, pomalidomide and an anti-CD38 monoclonal antibody. Seven of 8 (88%) had prior autologous stem cell transplant and 4 of 8 (50%) have IMWG high risk cytogenetics. As of the data cut, no DLTs have been observed at the first 2 DLs. Cytokine release syndrome (CRS), all grade 1 or 2, was observed in 6 of 8 (75%) patients. Median onset of CRS was 9 days (range 4 - 10) with a median duration of 4.5 days (range 2 - 19 days). None of the patients with grade 2 CRS required vasopressor support and only 1 patient received tocilizumab. No patients had grade ≥ 3 CRS. Three of 8 (38%) patients experienced neurologic adverse events (AE). Two patients had grade 1 events, and 1 had a grade 3 event (lethargy), which resolved within 24 hours after receiving steroids. Onset of neurologic AEs was 9,11 and 12 days with a duration of 2, 3 and 1 days respectively. Notably, the patient who experienced grade 3 neurotoxicity (NT), developed secondary plasma cell leukemia (PCL) just prior to receiving LDC. All 8 patients have evidence of objective response (≥ MR), including the patient with secondary PCL. 3 patients, all treated at DL1 (50 x 106 CAR+ T-cells), have confirmed responses (1 PR, 2 sCR) with the remainder unconfirmed (1 CR, 2 VGPR, 1 PR, 1 MR). As of the data cut, no patients have progressed. Additional clinical and translational data on at least 30 patients and additional follow up of at least 4 months will be available at time of presentation. Conclusion: At initial lower dose levels, JCARH125 showed an acceptable safety profile with no DLTs reported thus far. Incidence of grade ≥ 3 NT was low and no grade ≥ 3 CRS has occurred with clear clinical activity. Although durability of response and response rate in a greater number of patients remain to be determined, early experience with JCARH125 support a favorable risk-benefit profile and rapid clinical development. Disclosures Mailankody: Takeda: Research Funding; Janssen: Research Funding; Physician Education Resource: Honoraria; Juno: Research Funding. Bensinger:celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; amgen: Speakers Bureau; Takeda: Speakers Bureau; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Devries:Junot Therapeutics: Employment. Piasecki:Juno Therapeutics: Employment, Equity Ownership; Cascadian Therapeutics: Patents & Royalties; Amgen: Patents & Royalties. Ziyad:Juno Therapeutics: Employment, Equity Ownership. Blake:Celgene: Employment, Equity Ownership. Byon:Juno Therapeutics: Employment, Equity Ownership. Jakubowiak:Janssen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Adaptive Biotechnologies: Consultancy, Honoraria; SkylineDx: Consultancy, Honoraria.

scholarly journals Superior Efficacy of CAR-T Cells Using Marrow-Infiltrating Lymphocytes (MILsTM) As Compared to Peripheral Blood Lymphocytes (PBLs)

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4437-4437 ◽  
Author(s):  
Eric R. Lutz ◽  
Srikanta Jana ◽  
Lakshmi Rudraraju ◽  
Elizabeth DeOliveira ◽  
Jing Zhou ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Employment Equity ◽  
Car T Cells ◽  
Car T ◽  
Equity Ownership

Background The type of T cell used in generating chimeric antigen receptor (CAR) T cells is an important choice. Evidence suggests that T cells that are early in the effector/memory differentiation pathway with more stemness and greater potential to persist are better than more differentiated T cells with less stemness that are more readily exhausted and have less potential to persist. Marrow-infiltrating Lymphocytes (MILsTM) is a novel form of adoptive T cell therapy composed of patient-autologous, polyclonal CD4 and CD8 T cells that are activated and expanded from the bone marrow. Genetically unmodified MILsTM have demonstrated antitumor activity in patients with multiple myeloma and are being developed for several other tumor types, including non-small cell lung cancer and other solid tumors. Distinguishing features of bone marrow T cells used to produce MILsTM include their memory phenotype, inherent tumor antigen-specificity, higher CD8:CD4 ratio and ability to persist long-term when compared to peripheral blood lymphocytes (PBLs) which is the T cell source used to produce currently approved CAR-T therapies. Based on these differences, we hypothesize that MILsTM provide a more robust and better fit platform for CAR-T therapy compared to PBLs. Using a CD38-specific, 4-1BB/CD3z-signaling CAR as an initial model, we have demonstrated the feasibility of producing CAR-modified MILsTM (CAR-MILsTM) and showed that CAR-MILsTM demonstrate superior killing in vitro compared to CAR-T cells generated from patient-matched PBLs (CAR-PBLs). Herein, we build on our previous data and add a second BCMA-specific CAR model. We use the two multiple myeloma model systems to compare cytolytic potential, functionality, and expression of phenotypic markers of memory, stemness and exhaustion between patient-matched CAR-MILsTM and CAR-PBLs. Methods Matched pairs of CAR-MILsTM and CAR-PBLs were produced from the bone marrow and blood of multiple myeloma patients. Two different in vitro cytotoxicity assays, the RTCA xCelligence real-time impedance and FACS assays, were used to evaluate antigen-specific killing of target tumor cells. Functionality of CD4 and CD8 CAR-T cells, at the single-cell level, was evaluated by measuring the secretion of 32 cytokines and chemokines following in vitro antigen-specific stimulation using IsoPlexis IsoCode chips and analyzed using IsoPeak. Expression of markers of T cell memory (CD45RO & CCR7/CD62L), stemness (CD27) and exhaustion (PD1 & TIM3) on CAR-MILsTM and CAR-PBLs prior to and following antigen-specific stimulation was evaluated by flow-cytometry (FACS). Results CAR-MILsTM demonstrated superior killing of tumor target cells in vitro, regardless of the antigen specificity of the CAR, when compared to matched CAR-PBLs and this superiority persisted even upon repeated antigen encounter - a factor that may be critical in guaranteeing better anti-tumor efficacy and persistence. CAR-MILsTM demonstrated increased polyfunctionality (secretion of 2+ cytokines per cell) and an increased polyfunctional strength index (PSI) following antigen-stimulation compared to CAR-PBL in both CD4 and CD8 T cells. The enhanced PSI in CAR-MILsTM was predominately mediated by effector, stimulatory and chemoattractive proteins associated with antitumor activity including Granzyme B, IFNg, IL-8, MIP1a and MIP1b. Coincidentally, increased PSI and enhanced secretion of these same proteins was reported to be associated with improved clinical responses in patients with Non-Hodgkin lymphoma treated with CD19-specific CAR-T therapy. Expression of memory markers on CD4 and CD8 T cells were similar in CAR-MILsTM and CAR-PBLs both prior to and following antigen-stimulation. Although expression of CD27, PD1 and TIM3 were similar at baseline, CAR-MILs maintained higher levels of CD27 and lower levels of PD1 and TIM3 compared to CAR-PBLs following antigen-stimulation in both CD4 and CD8 T cells. Conclusions Collectively, our data suggest that CAR-MILsTM have several advantages over CAR-PBLs, including increased cytolytic potential, enhanced polyfunctionality, increased stemness and less exhaustion. Based on these differences and the inherent antitumor properties of MILsTM, we speculate that CAR-MILsTM would be more potent and effective than currently approved CAR-T products derived from PBLs. Disclosures Lutz: WindMIL Therapeutics: Employment, Equity Ownership. Jana:WindMIL Therapeutics: Employment, Equity Ownership. Rudraraju:WindMIL Therapeutics: Employment, Equity Ownership. DeOliveira:WindMIL Therapeutics: Employment, Equity Ownership. Zhou:Isoplexis: Employment, Equity Ownership. Mackay:Isoplexis: Employment, Equity Ownership. Borrello:Aduro: Patents & Royalties: intellectual property on allogeneic MM GVAX; BMS: Consultancy; WindMIL Therapeutics: Equity Ownership, Patents & Royalties, Research Funding; Celgene: Honoraria, Research Funding, Speakers Bureau. Noonan:WindMIL Therapeutics: Employment, Equity Ownership, Patents & Royalties; Aduro: Patents & Royalties: intellectual property on allogeneic MM GVAX.

scholarly journals Characterization of Lentiviral Vector Derived Anti-Bcma CAR T Cells Reveals Key Parameters for Robust Manufacturing of Cell-Based Gene Therapies for Multiple Myeloma

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3243-3243
Author(s):  
Graham Lilley ◽  
Alden Ladd ◽  
Daniel Cossette ◽  
Laura Viggiano ◽  
Gregory Hopkins ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
T Cell ◽  
Lentiviral Vector ◽  
Employment Equity ◽  
Cell Product ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership

Abstract T cells engineered with chimeric antigen receptors (CAR) specific to CD19 have caused rapid and durable clinical responses in ~90% of patients with acute lymphoblastic leukemia. These data support the development of additional CAR T cell products for the treatment of other hematological malignancies. Recently, B cell maturation antigen (BCMA) expression has been proposed as a marker for identification of malignant plasma cells in patients with multiple myeloma (MM). Nearly all MM and some non-Hodgkin's lymphoma tumor cells express BCMA, while normal tissue expression is restricted to plasma cells and a subset of mature B cells. Therefore, BCMA is an attractive CAR T cell target to treat patients with MM and some B cell lymphomas. To this end, using lentiviral vector technology, we successfully generated CAR T cells specific to BCMA that exhibit potent anti-tumor activity to both multiple myeloma and Burkitt's lymphoma in animal models. Manufacture of CAR T cells for individual patient treatment requires the establishment of a robust and reproducible process - since variability in manufacturing could impact the potency of each cell product. To begin to understand the parameters of the manufacturing process that might contribute to the activity of the final product, we first tested the impact of lentiviral vector (LVV) multiplicity of infection (MOI) on CAR T cell phenotype and function. Using a broad range of MOIs (0.625 to 40) across multiple independent PBMC donors we observed no differences in population doubling or cell size throughout the ~10 day manufacturing process, irrespective of the MOI used. As expected, the number of anti-BCMA CAR expressing cells, the level of CAR expression per cell and the average vector copy number (VCN) in the cell product increased proportionally with MOI. Similarly, T cell function, as determined by an IFNg cytokine release assay in response to BCMA-expressing K562 target cells, was also correlated with the LVV MOI. Notably, increased IFNg expression was readily observable at MOIs as low as 1.25 and reached a plateau with T cells generated using an MOI of 20 or more - highlighting the sensitivity of this functional assay. Analogous data demonstrating MOI dependent in vitro killing activity were obtained using a BCMA-expressing tumor cell cytotoxicity assay. Varying the LVV MOI used during transduction simultaneously alters both the amount of anti-BCMA CAR molecules expressed per cell as well as the number of T cells in the cell product that express anti-BCMA CAR. To evaluate each variable in isolation we generated T cell products containing the same frequency of anti-BCMA CAR T cells (26 ± 4% CAR+ T cells) but different levels of anti-BCMA expression per cell by diluting T cell products made with MOIs from 5 to 40 with donor-matched untransduced cells. While these populations had markedly different levels of CAR surface expression per cell (based on anti-BCMA CAR MFI levels measured by flow cytometry) both low and high expressing anti-BCMA CAR T cell products exhibited identical levels of cytotoxicity against BCMA-expressing tumor cells. These data suggest it is the number of CAR expressing cells that is the critical driver of higher functional activity (perhaps due to the efficiency of LVV mediated anti-BCMA CAR expression per transduced cell). Finally, using this information the variability in manufacturing of anti-BCMA CAR T cells was evaluated across 11 independent normal PBMC donors. All 11 products demonstrated very similar properties with respect to cell growth (population doublings, cell volume), and VCN. Importantly, using our standard MOI we obtained a consistent and high level of anti-BCMA CAR expressing T cells that resulted in robust IFNg cytokine release when co-cultured with BCMA-expression cells. Together, our data highlight the frequency of anti-BCMA CAR T cells per cell product as a key parameter for anti-tumor activity in vitro. Moreover, these data suggest that our LVV driven T cell engineering process can reproducibly generate robust anti-BCMA CAR expressing T cell products in a donor independent manner. A phase I clinical trial to evaluate this technology as a cell-based gene therapy for MM is under development. Disclosures Lilley: bluebird bio, Inc: Employment, Equity Ownership. Ladd:bluebird bio, Inc: Employment, Equity Ownership. Cossette:bluebird bio, Inc: Employment, Equity Ownership. Viggiano:bluebird bio, Inc: Employment, Equity Ownership. Hopkins:bluebird bio, Inc: Employment, Equity Ownership. Evans:bluebird bio, Inc: Employment, Equity Ownership. Li:bluebird bio, Inc: Employment, Equity Ownership. Latimer:bluebird bio: Employment, Equity Ownership. Miller:bluebird bio: Employment, Equity Ownership. Kuczewski:bluebird bio: Employment, Equity Ownership. Bakeman:bluebird bio, Inc: Employment, Equity Ownership. MacLeod:bluebird bio, Inc: Employment, Equity Ownership. Friedman:bluebird bio: Employment, Equity Ownership. Maier:bluebird bio, Inc: Employment, Equity Ownership. Paglia:bluebird bio, Inc: Employment, Equity Ownership. Morgan:bluebird bio: Employment, Equity Ownership. Angelino:bluebird bio, Inc: Employment, Equity Ownership.

Combination Immunotherapy with NY-ESO-1-Specific CAR+ T Cells with T-Cell Vaccine Improves Anti-Myeloma Effect

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3366-3366 ◽  
Author(s):  
Krina Patel ◽  
Simon Olivares ◽  
Harjeet Singh ◽  
Lenka V. Hurton ◽  
Mary Helen Huls ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
T Cells ◽  
T Cell ◽  
Sleeping Beauty ◽  
Employment Equity ◽  
Effector Cells ◽  
T Effector Cells ◽  
Car T Cells ◽  
Car T ◽  
Equity Ownership

Abstract Adoptive transfer of T cells expressing chimeric antigen receptor (CAR) has demonstrated clinical effectiveness in early phase clinical trials, with persistence of effector cells typically leading to improved outcomes. Most CARs directly dock with cell-surface antigens, but this limits the number of tumor-derived targets. Thus, we have adapted two technologies to target intracellular antigens and improve survival of infused T cells. This was accomplished by expressing a CAR on T effector cells that functions as a mimetic of T-cell receptor (TCR) to recognize NY-ESO-1 in the context of HLA A2 and adapting HLA-A2+ T cells to serve as antigen presenting cells (T-APC) by expressing NY-ESO-1 antigen. NY-ESO-1 is a desirable target for T-cell therapy of high risk multiple myeloma (MM) with efficacy in trials infusing T cells expressing TCR recognizing this antigen. We hypothesized combined immunotherapy with NY-ESO-1-specific CAR+ T cells and an NY-ESO-1+ T-APC vaccine will lead to enhanced anti-myeloma efficacy due to improved persistence of the CAR+ T effector cells. An NY-ESO-1-specific CAR and control TCR were expressed on primary T cells using the Sleeping Beauty (SB) transposon/transposase system. T-APC was generated by electro-transfer of DNA plasmids from SB system coding for NY-ESO-1 and membrane-bound IL-15 (mbIL15). The tethered cytokine functions as co-stimulatory molecule to improve the potency of the vaccine. In vitro studies confirmed the NY-ESO-1-specific CAR+ (and TCR+) T cells could be numerically expanded upon co-culture with T-APC. A mouse model of NY-ESO-1+HLA-A2+(CD19neg) multiple myeloma was used to compare tumor growth for CAR+ T effector cells with and without T-APC. The NY-ESO-1-specific CAR+ T effector cells displayed anti-tumor effect that was superior to control mice without T cells and mice receiving CD19-specific control CAR+ T cells. Mice receiving both NY-ESO-1-specific CAR+T effector cells and T-APC exhibited further improvement in anti-myeloma activity. This group demonstrated superior persistence of T effector cells with recovered cells exhibiting a memory phenotype. In summary, T cells can target intracellular NY-ESO-1 using a TCR mimetic CAR. Improved anti-tumor effect attributed to better persistence can be achieved by co-infusion of T-APC vaccine. These data provide the foundation to assess T cells targeting NY-ESO-1 in a clinical trial. Disclosures Patel: Ziopharm Oncology: Equity Ownership, Patents & Royalties; Intrexon: Equity Ownership, Patents & Royalties. Olivares:Ziopharm Oncology: Equity Ownership, Patents & Royalties; Intrexon: Equity Ownership, Patents & Royalties. Singh:Ziopharm Oncology: Equity Ownership, Patents & Royalties; Immatics: Equity Ownership, Patents & Royalties; Intrexon: Equity Ownership, Patents & Royalties. Hurton:Ziopharm Oncology: Equity Ownership, Patents & Royalties; Intrexon: Equity Ownership, Patents & Royalties. Huls:Ziopharm Oncology: Equity Ownership, Patents & Royalties; Intrexon: Employment, Equity Ownership, Patents & Royalties. Cooper:City of Hope: Patents & Royalties; Intrexon: Equity Ownership; Ziopharm Oncology: Employment, Equity Ownership, Patents & Royalties; Targazyme, Inc.,: Equity Ownership; Immatics: Equity Ownership; Sangamo BioSciences: Patents & Royalties; MD Anderson Cancer Center: Employment; Miltenyi Biotec: Honoraria.

scholarly journals Preclinical Evaluation of ALLO-819, an Allogeneic CAR T Cell Therapy Targeting FLT3 for the Treatment of Acute Myeloid Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3921-3921 ◽  
Author(s):  
Cesar Sommer ◽  
Hsin-Yuan Cheng ◽  
Yik Andy Yeung ◽  
Duy Nguyen ◽  
Janette Sutton ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Target Cells ◽  
Employment Equity ◽  
T Cell Therapy ◽  
Cell Therapies ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership

Autologous chimeric antigen receptor (CAR) T cells have achieved unprecedented clinical responses in patients with B-cell leukemias, lymphomas and multiple myeloma, raising interest in using CAR T cell therapies in AML. These therapies are produced using a patient's own T cells, an approach that has inherent challenges, including requiring significant time for production, complex supply chain logistics, separate GMP manufacturing for each patient, and variability in performance of patient-derived cells. Given the rapid pace of disease progression combined with limitations associated with the autologous approach and treatment-induced lymphopenia, many patients with AML may not receive treatment. Allogeneic CAR T (AlloCAR T) cell therapies, which utilize cells from healthy donors, may provide greater convenience with readily available off-the-shelf CAR T cells on-demand, reliable product consistency, and accessibility at greater scale for more patients. To create an allogeneic product, the TRAC and CD52 genes are inactivated in CAR T cells using Transcription Activator-Like Effector Nuclease (TALEN®) technology. These genetic modifications are intended to minimize the risk of graft-versus-host disease and to confer resistance to ALLO-647, an anti-CD52 antibody that can be used as part of the conditioning regimen to deplete host alloreactive immune cells potentially leading to increased persistence and efficacy of the infused allogeneic cells. We have previously described the functional screening of a library of anti-FLT3 single-chain variable fragments (scFvs) and the identification of a lead FLT3 CAR with optimal activity against AML cells and featuring an off-switch activated by rituximab. Here we characterize ALLO-819, an allogeneic FLT3 CAR T cell product, for its antitumor efficacy and expansion in orthotopic models of human AML, cytotoxicity in the presence of soluble FLT3 (sFLT3), performance compared with previously described anti-FLT3 CARs and potential for off-target binding of the scFv to normal human tissues. To produce ALLO-819, T cells derived from healthy donors were activated and transduced with a lentiviral construct for expression of the lead anti-FLT3 CAR followed by efficient knockout of TRAC and CD52. ALLO-819 manufactured from multiple donors was insensitive to ALLO-647 (100 µg/mL) in in vitro assays, suggesting that it would avoid elimination by the lymphodepletion regimen. In orthotopic models of AML (MV4-11 and EOL-1), ALLO-819 exhibited dose-dependent expansion and cytotoxic activity, with peak CAR T cell levels corresponding to maximal antitumor efficacy. Intriguingly, ALLO-819 showed earlier and more robust peak expansion in mice engrafted with MV4-11 target cells, which express lower levels of the antigen relative to EOL-1 cells (n=2 donors). To further assess the potency of ALLO-819, multiple anti-FLT3 scFvs that had been described in previous reports were cloned into lentiviral constructs that were used to generate CAR T cells following the standard protocol. In these comparative studies, the ALLO-819 CAR displayed high transduction efficiency and superior performance across different donors. Furthermore, the effector function of ALLO-819 was equivalent to that observed in FLT3 CAR T cells with normal expression of TCR and CD52, indicating no effects of TALEN® treatment on CAR T cell activity. Plasma levels of sFLT3 are frequently increased in patients with AML and correlate with tumor burden, raising the possibility that sFLT3 may act as a decoy for FLT3 CAR T cells. To rule out an inhibitory effect of sFLT3 on ALLO-819, effector and target cells were cultured overnight in the presence of increasing concentrations of recombinant sFLT3. We found that ALLO-819 retained its killing properties even in the presence of supraphysiological concentrations of sFLT3 (1 µg/mL). To investigate the potential for off-target binding of the ALLO-819 CAR to human tissues, tissue cross-reactivity studies were conducted using a recombinant protein consisting of the extracellular domain of the CAR fused to human IgG Fc. Consistent with the limited expression pattern of FLT3 and indicative of the high specificity of the lead scFv, no appreciable membrane staining was detected in any of the 36 normal tissues tested (n=3 donors). Taken together, our results support clinical development of ALLO-819 as a novel and effective CAR T cell therapy for the treatment of AML. Disclosures Sommer: Allogene Therapeutics, Inc.: Employment, Equity Ownership. Cheng:Allogene Therapeutics, Inc.: Employment, Equity Ownership. Yeung:Pfizer Inc.: Employment, Equity Ownership. Nguyen:Allogene Therapeutics, Inc.: Employment, Equity Ownership. Sutton:Allogene Therapeutics, Inc.: Employment, Equity Ownership. Melton:Allogene Therapeutics, Inc.: Employment, Equity Ownership. Valton:Cellectis, Inc.: Employment, Equity Ownership. Poulsen:Allogene Therapeutics, Inc.: Employment, Equity Ownership. Djuretic:Pfizer, Inc.: Employment, Equity Ownership. Van Blarcom:Allogene Therapeutics, Inc.: Employment, Equity Ownership. Chaparro-Riggers:Pfizer, Inc.: Employment, Equity Ownership. Sasu:Allogene Therapeutics, Inc.: Employment, Equity Ownership.

scholarly journals Safety and Efficacy of Anti-Bcma CAR-T Cells for Relapsed/Refractory Multiple Myeloma: A Systematic Review of Literature

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 5-6
Author(s):  
Israr Khan ◽  
Abdul Rafae ◽  
Anum Javaid ◽  
Zahoor Ahmed ◽  
Haifza Abeera Qadeer ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Multiple Myeloma ◽  
Clinical Trials ◽  
T Cells ◽  
Partial Response ◽  
Residual Disease ◽  
Safety And Efficacy ◽  
Refractory Multiple Myeloma ◽  
Car T Cells ◽  
Car T

Background: Multiple myeloma (MM) is a plasma cell disorder and demonstrates overexpression of B cell maturation antigen (BCMA). Our objective is to evaluate the safety and efficacy of chimeric antigen receptor T cells (CAR-T) against BCMA in patients with relapsed/refractory multiple myeloma (RRMM). Methods: We conducted a systematic literature search using PubMed, Cochrane, Clinicaltrials.gov, and Embase databases. We also searched for data from society meetings. A total of 935 articles were identified, and 610 were screened for relevance. Results: Data from thirty-one original studies with a total of 871 patients (pts) were included based on defined eligibility criteria, see Table 1. Hu et al. reported an overall response rate (ORR) of 100% in 33 pts treated with BCMA CAR-T cells including 21 complete response (CR), 7 very good partial response (VGPR), 4 partial response (PR). Moreover, 32 pts achieved minimal residual disease (MRD) negative status. Chen et al. reported ORR of 88%, 14% CR, 6% VGPR, and 82% MRD negative status with BCMA CAR-T therapy in 17 RRMM pts. In another clinical trial by Han et al. BCMA CAR-T therapy demonstrated an ORR of 100% among 7 evaluable pts with 43% pts having ≥ CR and 14% VGPR. An ORR of 100% with 64% stringent CR (sCR) and 36% VGPR was reported with novel anti-BCMA CART cells (CT103A). Similarly, Li et al. reported ORR of 87.5%, sCR of 50%, VGPR 12.5%, and PR 25% in 16 pts. BCMA targeting agent, JNJ-4528, showed ORR of 91%, including 4sCR, 2CR, 10MRD, and 7VGPR. CAR-T- bb2121 demonstrated ORR of 85%, sCR 36%, CR 9%, VGPR 57%, and MRD negativity of 100% (among 16 responsive pts). GSK2857916, a BCMA targeting CAR-T cells yielded ORR of 60% in both clinical trials. Three studies utilizing bispecific CART cells targeting both BCMA & CD38 (LCARB38M) reported by Zhao et al., Wang et al., and Fan et al. showed ORR of 88%, 88%, & 100% respectively. Topp et al. reported ORR of 31% along with 5 ≥CR and 5 MRD negative status in 42 pts treated with Bi T-cells Engager BiTE® Ab BCMA targeting antigen (AMG420). One clinical trial presented AUTO2 CART cells therapy against BCMA with an ORR of 43%, VGPR of 14%, and PR of 28%. CT053CAR-BCMA showed 14sCR and 5CR with a collective ORR of 87.5% and MRD negative status of 85% in 24 and 20 evaluable pts, respectively. Likewise, Mikkilineni et al. reported an ORR of 83%, sCR of 16.7%, and VGPR & PR of 25% and 41% in 12 pts treated with FHVH-BCMA T cells. Similar results are also reported in other clinical trials of BCMA targeting CART therapy (Table 1). The most common adverse effects exhibited were grade 1-3 hematologic (cytopenia) and cytokine release syndrome (CRS) (mostly reversible with tocilizumab). Conclusion: Initial data from ongoing clinical trials using BCMA targeting CAR-T therapy have yielded promising results both in terms of improved outcome and tolerable toxicity profiles. Although two phase 3 trails are ongoing, additional data is warranted to further ensure the safety and efficacy of anti-BCMA CAR-T cells therapy in pts with RRMM for future use. Disclosures Anwer: Incyte, Seattle Genetics, Acetylon Pharmaceuticals, AbbVie Pharma, Astellas Pharma, Celegene, Millennium Pharmaceuticals.: Honoraria, Research Funding, Speakers Bureau.

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