scholarly journals Preliminary Results of UCART19, an Allogeneic Anti-CD19 CAR T-Cell Product, in a First-in-Human Trial (CALM) in Adult Patients with CD19+ Relapsed/Refractory B-Cell Acute Lymphoblastic Leukemia

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 887-887
Author(s):  
Charlotte Graham ◽  
Deborah Yallop ◽  
Agnieszka Jozwik ◽  
Piers Patten ◽  
Alan Dunlop ◽  
...  
Keyword(s):  
T Cell ◽  
Research Funding ◽  
Disease Burden ◽  
Advisory Board ◽  
Employment Equity ◽  
Human Trial ◽  
Preliminary Results ◽  
Educational Meeting ◽  
Car T ◽  
Equity Ownership

Abstract Background UCART19 is a genetically modified T-cell product manufactured from non-HLA matched healthy donor cells. Lentiviral-transduced CAR T-cells express (1) an anti-CD19 CAR (anti-CD19 scFv- 41BB- CD3ζ) and (2) an RQR8 "safety switch" that is intended to allow targeted elimination of RQR8+ cells by rituximab. UCART19 has been additionally modified to disrupt the T-cell receptor alpha constant (TRAC) and CD52 genes. The preliminary results of this "off-the-shelf" allogeneic CAR T-cell therapy in a phase I, dose-escalation trial of UCART19 in CD19+ R/R B-ALL adult patients (pts) are described. Methods The primary objective of this study is to determine the maximum tolerated dose of UCART19 by investigating up to four dose levels (DL) in separate sequential cohorts. Adult pts (age ≥16 years) with CD19+ R/R B-ALL who have exhausted available treatment options are eligible. Disease burden must be quantifiable morphologically or with a minimal residual disease (MRD) load ≥1x10-3 at the end of the last anti-leukemic treatment. The lymphodepletion regimen combines cyclophosphamide and fludarabine, with or without alemtuzumab (FC or FCA). A single dose of UCART19 is administered on Day 0, and pts are closely monitored for safety and anti-leukemic activity until the end of study, 3 months after UCART19 administration. Pts are then rolled-over into a 15-years long-term follow-up study. The dose escalation follows a modified Toxicity Probability Interval (mTPI) design based on the occurrence of dose-limiting toxicity (DLT) assessed at the end of the 28-day evaluation period post UCART19 (D28). Results As of 24 June 2017, the 2 first cohorts (3 pts each) who received the first DL (DL1=6x106 total CAR+ cells) have been completed. Median age was 22.5 years (range 18-42). Pts received 1 to 5 previous lines of treatment with 5 out of 6 pts having undergone an allogeneic stem cell transplant (allo-SCT). Four of them had relapsed within 4-6 months post-transplant. Prior to UCART19 infusion, 4 pts had low disease burden (<5% leukemic blasts in bone marrow (BM)) and 2 pts had high disease burden (69 and 100% blasts respectively). All pts received lymphodepletion with FCA. All pts experienced cytokine release syndrome (CRS): 1 G1, 4 G2 and 1 G4. CRS G1 and G2 were manageable by supportive care ± tocilizumab. CRS G4, assessed as a DLT, occurred in the context of neutropenic sepsis, and was considered to be a contributory factor in the patient's death from multiple organ failure at D15. Time to onset of first CRS symptoms ranged between D5 and D10. CRS correlated with serum cytokine increase (IL-6; IL-10 and INFγ) and UCART19 expansion in the blood. One patient was reported to have probable skin GvHD G1. Only G1 neurotoxic events were observed in 1 patient. Asymptomatic viral reactivations (CMV and/or adenovirus) were seen in 3 pts and resolved with antiviral therapy. Among the 6 pts, 4 achieved a CRi with MRD negativity at D28 (MRD-ve, defined as a tumor burden <0.01% assessed by flow cytometry and/or qPCR), 1 was refractory to treatment at D28 and 1 died at D15. All 4 pts achieving MRD-ve remission underwent a subsequent allo-SCT, 3 of them within 3 months of UCART19 infusion and 1 following retreatment with FC lymphodepletion and the same dose of UCART19, this patient having relapsed with CD19+ disease 2 months post initial UCART19 infusion. Post allo-SCT, 1 patient relapsed at 100 days with CD19+ disease, 1 died from infection and 2 remain in complete remission. Three pts remain alive at 2.4, 5.3 and 10.2 months respectively post UCART19 treatment. UCART19 (both cells and transgene levels) peaked between D12 and D17 in blood (flow cytometry [figure 1] and qPCR, respectively). UCART19 was detectable in blood from D10 to D28 (up to D42 in 1 patient) and in BM aspirates performed at D14 and D28. In-vivo cell expansion in BM occurred in all but the refractory patient. Conclusion Preliminary results of this first-in-human trial of UCART19 treatment in a high risk R/R B-ALL adult population revealed no unexpected toxicities. Asymptomatic lymphodepletion-related viral reactivations and a probable skin GvHD G1 were encountered. CRi with MRD-ve was achieved in 4 out of 5 pts who reached D28. The 2 first cohorts treated at DL1 have been completed and DL2 will now be investigated on which further results may be presented. The study is active in the UK and will be expanded to other EU countries and the US (NCT 02746952). Disclosures Graham: Servier: Research Funding; Pfizer: Other: Educational meeting attendance; Gilead: Other: Educational meeting attendance; Sanofi: Other: Educational meeting attendance. Yallop: Jazz Pharmaceuticals: Honoraria; Amgen: Honoraria; Pfizer: Other: Advisory board. Jozwik: Servier: Research Funding. Patten: Gilead Inc: Honoraria, Research Funding; Roche: Honoraria; Abbvie: Honoraria. Ellard: Moldmed: Honoraria. Potter: Pfizer: Other: Advisory board; Jazz: Honoraria. Devereux: AbbVie: Consultancy, Honoraria; MSD: Consultancy, Honoraria; Roche: Consultancy, Other: travel expenses; GSK: Consultancy; Gilead: Consultancy, Honoraria, Other: travel expenses, Speakers Bureau; Janssen: Consultancy, Honoraria, Other: travel expenses, Speakers Bureau; Servier: Other: Advisory board. Pagliuca: Jazz: Honoraria; Merck: Honoraria, Research Funding; Bluebird: Honoraria; Pfizer: Honoraria; Basilea: Honoraria; Astellas: Consultancy, Speakers Bureau; Gilead: Honoraria. Zinai: Servier: Employment. Binlich: Servier: Employment. Dupouy: Servier: Employment. Philippe: Servier: Employment. Balandraud: Servier: Employment. Dubois: Servier: Employment. Konto: Bristol-Myers Squibb: Employment, Equity Ownership; Pfizer: Employment, Equity Ownership. Patel: Pfizer: Employment, Equity Ownership. Benjamin: Pfizer: Other: Participated in Adboard meeting, Research Funding; Servier: Research Funding; Celgene: Honoraria.

scholarly journals Combination of NKTR-255, a Polymer Conjugated Human IL-15, with CD19 CAR T Cell Immunotherapy in a Preclinical Lymphoma Model

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2866-2866 ◽  
Author(s):  
Cassie Chou ◽  
Simon Fraessle ◽  
Rachel Steinmetz ◽  
Reed M. Hawkins ◽  
Tinh-Doan Phi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Research Funding ◽  
Board Member ◽  
Ad Hoc ◽  
Advisory Board ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership

Background CD19 CAR T immunotherapy has been successful in achieving durable remissions in some patients with relapsed/refractory B cell lymphomas, but disease progression and loss of CAR T cell persistence remains problematic. Interleukin 15 (IL-15) is known to support T cell proliferation and survival, and therefore may enhance CAR T cell efficacy, however, utilizing native IL-15 is challenging due to its short half-life and poor tolerability in the clinical setting. NKTR-255 is a polymer-conjugated IL-15 that retains binding affinity to IL15Rα and exhibits reduced clearance, providing sustained pharmacodynamic responses. We investigated the effects of NKTR-255 on human CD19 CAR T cells both in vitro and in an in vivo xenogeneic B cell lymphoma model and found improved survival of lymphoma bearing mice receiving NKTR-255 and CAR T cells compared to CAR T cells alone. Here, we extend upon these findings to further characterize CAR T cells in vivo and examine potential mechanisms underlying improved anti-tumor efficacy. Methods CD19 CAR T cells incorporating 4-1BB co-stimulation were generated from CD8 and CD4 T cells isolated from healthy donors. For in vitro studies, CAR T cells were incubated with NKTR-255 or native IL-15 with and without CD19 antigen. STAT5 phosphorylation, CAR T cell phenotype and CFSE dilution were assessed by flow cytometry and cytokine production by Luminex. For in vivo studies, NSG mice received 5x105 Raji lymphoma cells IV on day (D)-7 and a subtherapeutic dose (0.8x106) of CAR T cells (1:1 CD4:CD8) on D0. To determine optimal start date of NKTR-255, mice were treated weekly starting on D-1, 7, or 14 post CAR T cell infusion. Tumors were assessed by bioluminescence imaging. Tumor-free mice were re-challenged with Raji cells. For necropsy studies mice received NKTR-255 every 7 days following CAR T cell infusion and were euthanized at various timepoints post CAR T cell infusion. Results Treatment of CD8 and CD4 CAR T cells in vitro with NKTR-255 resulted in dose dependent STAT5 phosphorylation and antigen independent proliferation. Co-culture of CD8 CAR T cells with CD19 positive targets and NKTR-255 led to enhanced proliferation, expansion and TNFα and IFNγ production, particularly at lower effector to target ratios. Further studies showed that treatment of CD8 CAR T cells with NKTR-255 led to decreased expression of activated caspase 3 and increased expression of bcl-2. In Raji lymphoma bearing NSG mice, administration of NKTR-255 in combination with CAR T cells increased peak CAR T cell numbers, Ki-67 expression and persistence in the bone marrow compared to mice receiving CAR T cells alone. There was a higher percentage of EMRA like (CD45RA+CCR7-) CD4 and CD8 CAR T cells in NKTR-255 treated mice compared to mice treated with CAR T cells alone and persistent CAR T cells in mice treated with NKTR-255 were able to reject re-challenge of Raji tumor cells. Additionally, starting NKTR-255 on D7 post T cell infusion resulted in superior tumor control and survival compared to starting NKTR-255 on D-1 or D14. Conclusion Administration of NKTR-255 in combination with CD19 CAR T cells leads to improved anti-tumor efficacy making NKTR-255 an attractive candidate for enhancing CAR T cell therapy in the clinic. Disclosures Chou: Nektar Therapeutics: Other: Travel grant. Fraessle:Technical University of Munich: Patents & Royalties. Busch:Juno Therapeutics/Celgene: Consultancy, Equity Ownership, Research Funding; Kite Pharma: Equity Ownership; Technical University of Munich: Patents & Royalties. Miyazaki:Nektar Therapeutics: Employment, Equity Ownership. Marcondes:Nektar Therapeutics: Employment, Equity Ownership. Riddell:Juno Therapeutics: Equity Ownership, Patents & Royalties, Research Funding; Adaptive Biotechnologies: Consultancy; Lyell Immunopharma: Equity Ownership, Patents & Royalties, Research Funding. Turtle:Allogene: Other: Ad hoc advisory board member; Novartis: Other: Ad hoc advisory board member; Humanigen: Other: Ad hoc advisory board member; Nektar Therapeutics: Other: Ad hoc advisory board member, Research Funding; Caribou Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; T-CURX: Membership on an entity's Board of Directors or advisory committees; Juno Therapeutics: Patents & Royalties: Co-inventor with staff from Juno Therapeutics; pending, Research Funding; Precision Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Eureka Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Kite/Gilead: Other: Ad hoc advisory board member.

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 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 (>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<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 (>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 >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 >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 Initial Results from a Phase 1 Clinical Study of bb21217, a Next-Generation Anti Bcma CAR T Therapy

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 488-488 ◽  
Author(s):  
Nina Shah ◽  
Melissa Alsina ◽  
David S Siegel ◽  
Sundar Jagannath ◽  
Deepu Madduri ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Phase 1 ◽  
Employment Equity ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership

Abstract Introduction: Immunomodulatory chimeric antigen receptor (CAR) T cell therapy directed against B-cell maturation antigen (BCMA) has shown promising results for the treatment of relapsed refractory multiple myeloma (RRMM) in several phase 1 clinical studies in patients with advanced disease. Persistence of CAR T cells post infusion may be one determinant of duration of response. bb21217 is a next-generation anti-BCMA CAR T cell therapy based on investigational therapy bb2121 (Friedman 2018, Hum Gene Ther 29:585). It uses the same scFv, 4-1BB costimulatory motif and CD3-zeta T cell activation domain as bb2121 with the addition of phosphoinositide 3 kinase inhibitor bb007 during ex vivo culture to enrich the drug product for T cells displaying a memory-like phenotype. Evidence suggests that CAR T cells with this phenotype may be more persistent and more potent than unselected CAR T cells. CRB-402 is a first-in-human clinical study of bb21217 in patients with RRMM designed to assess the safety, pharmacokinetics, efficacy and duration of effect of bb21217. Methods: CRB-402 (NCT03274219) is an ongoing, multi-center phase 1 dose escalation trial of bb21217 in approximately 50 patients with RRMM who have received ≥ 3 prior regimens, including a proteasome inhibitor and an immuno-modulatory agent, or are double-refractory. During dose escalation, enrollment is restricted to patients with ≥ 50% BCMA expression by IHC on malignant plasma cells. Peripheral blood mononuclear cells are collected via leukapheresis and sent 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 bb21217 as a single infusion. Planned dose levels are 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 are quality and duration of clinical response assessed according to the IMWG Uniform Response Criteria for MM, evaluation of minimal residual disease (MRD), progression-free and overall survival, and quantification of CAR+ cells in blood. Results: Asof June 15, 2018, 8 patients (median age 64 [min;max 54 to 70]) have received bb21217. All patients to date received a dose of 150 x 106 CAR+ T cells. Four had high tumor burden, defined as ≥ 50% bone marrow plasma cells pre-infusion. Patients had a median of 9 (min;max 4 to 17) prior lines of therapy and 7/8 had prior autologous stem cell transplant; 50% had high-risk cytogenetics. Four of 8 (50%) had previously received Bort/Len/Car/Pom/Dara. Median follow-up after bb21217 infusion was 16 weeks (2 to 27 weeks) and 7 patients were evaluable for initial (1-month) clinical response. As of data cut-off, 5 of 8 patients developed cytokine release syndrome (CRS; 1 Grade 1, 3 Grade 2, 1 Grade 3) and responded to supportive care or tocilizumab. This included 1 patient with high tumor burden who experienced DLTs consisting of grade 3 CRS and grade 4 encephalopathy with signs of posterior reversible encephalopathy syndrome on MRI. This patient received tocilizumab, corticosteroids and cyclophosphamide, improved neurologically and achieved a sCR. Following this event, the dose escalation cohort was divided into two groups based on tumor burden and dosing continued at 150x106 CAR+ T cells. No deaths occurred. With 1 to 6 months since treatment, 6 of 7 patients had demonstrated clinical response per IMWG criteria: currently 1 sCR, 3 VGPR, 2 PR. MRD negative results at 10-5 nucleated cells were obtained by next-generation sequencing in 3 of 3 evaluable responders. Robust CAR+ T cell expansion during the first 30 days was observed in 7 of 7 evaluable patients. Two of 2 patients evaluable at 6 months had detectable CAR vector copies. Conclusions: Early efficacy results with bb21217 CAR T therapy in RRMM at a dose of 150 x 106 CAR+ T cells are encouraging, with 6 of 7 patients demonstrating clinical responses. The adverse events observed to date are consistent with known toxicities of CAR T therapies. CAR+ T cells were measurable at 6 months post treatment in both evaluable patients. Enrollment in the study is ongoing; longer follow-up and data in more patients will establish whether treatment with bb21217 results in sustained CAR+ T cell persistence and responses. Disclosures Shah: Kite: Consultancy; Indapta Therapeutics: Consultancy; University of California San Francisco: Employment; Nekktar: Consultancy; Teneobio: Consultancy; Sanofi: Consultancy; Janssen: Research Funding; Indapta Therapeutics: Equity Ownership; Amgen: Consultancy; Bluebird: Research Funding; Celgene: Research Funding; Bristol Myers Squibb: Consultancy; Takeda: Consultancy; Sutro Biopharma: Research Funding; Nkarta: Consultancy. Siegel:Takeda: Consultancy, Honoraria, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Merck: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau. Jagannath:Multiple Myeloma Research Foundation: Speakers Bureau; Merck: Consultancy; Novartis: Consultancy; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy; Medicom: Speakers Bureau. Kaufman:Karyopharm: Other: data monitoring committee; BMS: Consultancy; Janssen: Consultancy; Abbvie: Consultancy; Roche: Consultancy. Turka:bluebird bio, Inc: Employment, Equity Ownership. Lam:bluebird bio, Inc: Employment, Equity Ownership. Massaro:bluebird bio, Inc: Employment, Equity Ownership. Hege:Celgene Corporation: Employment, Equity Ownership, Patents & Royalties: multiple; Mersana: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; SITC: Membership on an entity's Board of Directors or advisory committees; Arcus Biosicences: Membership on an entity's Board of Directors or advisory committees. Petrocca:bluebird bio, Inc: Employment, Equity Ownership. Berdeja:Glenmark: Research Funding; Novartis: Research Funding; Genentech: Research Funding; Janssen: Research Funding; Bristol-Myers Squibb: Research Funding; Bluebird: Research Funding; Amgen: Research Funding; Celgene: Research Funding; Poseida Therapeutics, Inc.: Research Funding; Takeda: Research Funding; Teva: Research Funding; Sanofi: Research Funding. Raje:AstraZeneca: Research Funding; Takeda: Consultancy; Merck: Consultancy; Janssen: Consultancy; Celgene: Consultancy; BMS: Consultancy; Amgen Inc.: Consultancy; Research to Practice: Honoraria; Medscape: Honoraria.

scholarly journals Phase 2 Study of the Response and Safety of P-Bcma-101 CAR-T Cells in Patients with Relapsed/Refractory (r/r) Multiple Myeloma (MM) (PRIME)

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3184-3184 ◽  
Author(s):  
Caitlin L. Costello ◽  
Tara K. Gregory ◽  
Syed Abbas Ali ◽  
Jesus G. Berdeja ◽  
Krina K. Patel ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Phase 2 ◽  
Employment Equity ◽  
Advisory Committees ◽  
Car T Cells ◽  
Car T ◽  
Equity Ownership

P-BCMA-101 is a novel chimeric antigen receptor (CAR)-T cell product targeting B Cell Maturation Antigen (BCMA). P-BCMA-101 is produced using the piggyBac® (PB) DNA Modification System instead of the viral vector that is used with most CAR-T cells, requiring only plasmid DNA and mRNA. This makes it less costly and produces cells with a high percentage of the favorable T stem cell memory phenotype (TSCM). The higher cargo capacity of PB permits the incorporation of multiple genes in addition to CAR(s), including a safety switch allowing for rapid CAR-T cell elimination with a small molecule drug infusion in patients if desired, and a selection gene allowing for enrichment of CAR+ cells. Rather than using a traditional antibody-based binder, P-BCMA-101 has a Centyrin™ fused to a CD3ζ/4-1BB signaling domain. Centyrins are fully human proteins with high specificity and a large range of binding affinities, but are smaller, more stable and potentially less immunogenic than traditional scFv. Cumulatively, these features are predicted to result in a greater therapeutic index. A Phase 1, 3+3 dose escalation from 0.75 to 15 x 106 P-BCMA-101 CAR-T cells/kg (RP2D 6-15 x 106 cells/kg) was conducted in patients with r/r MM (Blood 2018 132:1012) demonstrating excellent efficacy and safety of P-BCMA-101, including notably low rates and grades of CRS and neurotoxicity (maximum Grade 2 without necessitating ICU admission, safety switch activation or other aggressive measures). These results supported FDA RMAT designation and initiation of a pivotal Phase 2 study. A Phase 2 pivotal portion of this study has recently been designed and initiated (PRIME; NCT03288493) in r/r MM patients who have received at least 3 prior lines of therapy. Their therapy must have contained a proteasome inhibitor, an IMiD, and CD38 targeted therapy with at least 2 of the prior lines in the form of triplet combinations. They must also have undergone ≥2 cycles of each line unless PD was the best response, refractory to the most recent line of therapy, and undergone autologous stem cell transplant or not be a candidate. Patients are required to be >=18 years old, have measurable disease by International Myeloma Working Group criteria (IMWG; Kumar 2016), adequate vital organ function and lack significant autoimmune, CNS and infectious diseases. No pre-specified level of BCMA expression is required, as this has not been demonstrated to correlate with clinical outcomes for P-BCMA-101 and other BCMA-targeted CAR-T products. Interestingly, unlike most CAR-T products patients may receive P-BCMA-101 after prior CAR-T cells or BCMA targeted agents, and may be multiply infused with P-BCMA-101. Patients are apheresed to harvest T cells, P-BCMA-101 is then manufactured and administered to patients as a single intravenous (IV) dose (6-15 x 106 P-BCMA-101 CAR-T cells/kg) after a standard 3-day cyclophosphamide (300 mg/m2/day) / fludarabine (30 mg/m2/day) conditioning regimen. One hundred patients are planned to be treated with P-BCMA-101. Uniquely, given the safety profile demonstrated during Phase 1, no hospital admission is required and patients may be administered P-BCMA-101 in an outpatient setting. The primary endpoints are safety and response rate by IMWG criteria. With a 100-subject sample, the Phase 2 part of the trial will have 90% power to detect a 15-percentage point improvement over a 30% response rate (based on that of the recently approved anti-CD38 antibody daratumumab), using an exact test for a binomial proportion with a 1-sided 0.05 significance level. Multiple biomarkers are being assessed including BCMA and cytokine levels, CAR-T cell kinetics, immunogenicity, T cell receptor diversity, CAR-T cell and patient gene expression (e.g. Nanostring) and others. Overall, the PRIME study is the first pivotal study of the unique P-BCMA-101 CAR-T product, and utilizes a number of novel design features. Studies are being initiated in combination with approved therapeutics and earlier lines of therapy with the intent of conducting Phase 3 trials. Funding by Poseida Therapeutics and the California Institute for Regenerative Medicine (CIRM). Disclosures Costello: Takeda: Honoraria, Research Funding; Janssen: Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Gregory:Poseida: Research Funding; Celgene: Speakers Bureau; Takeda: Speakers Bureau; Amgen: Speakers Bureau. Ali:Celgene: Research Funding; Poseida: Research Funding. Berdeja:Amgen Inc, BioClinica, Celgene Corporation, CRISPR Therapeutics, Bristol-Myers Squibb Company, Janssen Biotech Inc, Karyopharm Therapeutics, Kite Pharma Inc, Prothena, Servier, Takeda Oncology: Consultancy; AbbVie Inc, Amgen Inc, Acetylon Pharmaceuticals Inc, Bluebird Bio, Bristol-Myers Squibb Company, Celgene Corporation, Constellation Pharma, Curis Inc, Genentech, Glenmark Pharmaceuticals, Janssen Biotech Inc, Kesios Therapeutics, Lilly, Novartis, Poseida: Research Funding; Poseida: Research Funding. Patel:Oncopeptides, Nektar, Precision Biosciences, BMS: Consultancy; Takeda, Celgene, Janssen: Consultancy, Research Funding; Poseida Therapeutics, Cellectis, Abbvie: Research Funding. Shah:University of California, San Francisco: Employment; Genentech, Seattle Genetics, Oncopeptides, Karoypharm, Surface Oncology, Precision biosciences GSK, Nektar, Amgen, Indapta Therapeutics, Sanofi: Membership on an entity's Board of Directors or advisory committees; Indapta Therapeutics: Equity Ownership; Celgene, Janssen, Bluebird Bio, Sutro Biopharma: Research Funding; Poseida: Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Nkarta: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kite: Consultancy, Membership on an entity's Board of Directors or advisory committees; Teneobio: Consultancy, Membership on an entity's Board of Directors or advisory committees. Ostertag:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Martin:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Ghoddusi:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Shedlock:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Spear:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Orlowski:Poseida Therapeutics, Inc.: Research Funding. Cohen:Poseida Therapeutics, Inc.: Research Funding.

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 Transcend NHL 001: Immunotherapy with the CD19-Directed CAR T-Cell Product JCAR017 Results in High Complete Response Rates in Relapsed or Refractory B-Cell Non-Hodgkin Lymphoma

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4192-4192 ◽  
Author(s):  
Jeremy S. Abramson ◽  
Lia Palomba ◽  
Leo I Gordon ◽  
Matthew Lunning ◽  
Jon Arnason ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cell ◽  
Research Funding ◽  
Employment Equity ◽  
Car T Cells ◽  
Car T Cell ◽  
Non Hodgkin Lymphoma ◽  
Car T ◽  
Equity Ownership

Abstract Background: Based on promising results seen in patients treated with CD19-directed CAR-T cells in relapsed or refractory (R/R) pediatric B-cell acute lymphoblastic leukemia (Gardner, ASCO 2016) and adult B-cell non-Hodgkin lymphoma (Turtle, ASCO 2016), we are conducting a multicenter phase 1 trial of JCAR017 in R/R diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma (MCL) (ClinicalTrials.gov Identifier: NCT02631044). JCAR017 is a second-generation, CD19-directed CAR-T cell product of defined cellular composition consisting of a 1:1 ratio of CD8+:CD4+ CAR+ T cells. Methods: Patients with R/R DLBCL (de novo or transformed from indolent lymphoma), follicular lymphoma grade 3B, or MCL and adequate organ function are eligible. There was no minimum absolute lymphocyte count (ALC) requirement for apheresis and no test expansion required. Treatment includes lymphodepletion (fludarabine 30 mg/m2 and cyclophosphamide 300 mg/m2 daily for 3 days) and JCAR017 given 2-7 days post-lymphodepletion at a starting dose of 5 x 107 CAR+ T cells (DL1). Single-dose and two-dose schedules are being evaluated. Primary objectives include safety and pharmacokinetics (PK) of JCAR017 measured by flow cytometry and quantitative PCR. Secondary objectives include complete and overall response (CR, OR) rates and duration of response (DOR). Response is assessed using the Lugano (2014) criteria. Results: As of August 1, 2016, 39 patients have been enrolled and 28 patients apheresed. Fourteen patients have been treated, all at DL1. Eight were male and 6 female. Thirteen patients had DLBCL and 1 had MCL. Median age was 61 years (range 37-79) and median number of prior therapies was 5 (range 2-9). Ten patients had undergone prior transplant (7 autologous; 3 allogeneic). Of the 14 patients, there were no cases of severe cytokine release syndrome (sCRS); 3 patients had low grade CRS (21%) (2 grade 1; 1 grade 2) and none required treatment with tocilizumab. Two of the 14 treated patients (14%) had neurotoxicity: 1 grade 4 encephalopathy and 1 grade 4 seizure. Both were in patients with DLBCL and were dose-limiting toxicities. Two deaths were seen in the DLBCL group and were due to disease progression. Twelve patients had at least 1 post-treatment response assessment; 11 patients with DLBCL and 1 with MCL. The patient with MCL had progressive disease at day 29 (D29). In the DLBCL group, response rates were: 82% (9/11) OR, 73% (8/11) CR, 9% (1/11) PR and 18% (2/11) PD at the time of post-treatment assessment on D29. All but one patient who achieved a CR were in remission at the time of this data cut. One DLBCL patient in CR had a parenchymal brain lesion in the right temporal lobe that also completely resolved. Of note, this patient had no CRS or neurotoxicity associated with JCAR017 treatment. The PK profile of JCAR017 in the peripheral blood and bone marrow show cellular expansion in all patients with persistence out to at least 3 months in patients with adequate follow up. Exploratory biomarker analyses will be presented at the meeting along with updated clinical data. Conclusions: Treatment with the defined cellular composition product JCAR017 following lymphodepletion with fludarabine and cyclophosphamide results in high CR rates in patients with heavily pretreated DLBCL, including the first report of a CR in a patient with secondary CNS lymphoma. Observed toxicities are manageable and compare favorably to other reported CAR T-cell products. Disclosures Abramson: Gilead: Consultancy; Kite Pharma: Consultancy; Abbvie: Consultancy; Seattle Genetics: Consultancy. Gordon:Northwestern University: Patents & Royalties: Patent for gold nanoparticles pending. Lunning:Celgene: Consultancy; Bristol-Myer-Squibb: Consultancy; Pharmacyclics: Consultancy; Genentech: Consultancy; Juno: Consultancy; AbbVie: Consultancy; Gilead: Consultancy; TG Therapeutics: Consultancy; Spectrum: Consultancy. Arnason:Gilead: Consultancy. Forero-Torres:Genentech/Roche: Research Funding; Seattle Genetics: Research Funding; Juno: Research Funding; Incyte: Research Funding; Abbvie: Research Funding; Novartis: Research Funding; Pfizer: Research Funding. Albertson:Juno Therapeutics: Employment, Equity Ownership. Sutherland:Juno therapeutics: Employment. Xie:Juno Therapeutics: Employment, Equity Ownership. Snodgrass:Juno therapeutics: Employment. Siddiqi:Pharmacyclics, LLC, an AbbVie Company: Speakers Bureau; Janssen: Speakers Bureau; Seattle Genetics: Speakers Bureau; Kite pharma: Other: Funded travel, 1 day registration, and 1 night hotel stay for EHA2016 so I could present trial data there.

scholarly journals Flotetuzumab (FLZ), an Investigational CD123 x CD3 Bispecific Dart® Protein-Induced Clustering of CD3+ T Cells and CD123+ AML Cells in Bone Marrow Biopsies Is Associated with Response to Treatment in Primary Refractory AML Patients

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1410-1410 ◽  
Author(s):  
John E. Godwin ◽  
Carmen Ballesteros-Merino ◽  
Nikhil Lonberg ◽  
Shawn Jensen ◽  
Tarsem Moudgil ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Board Of Directors ◽  
Research Funding ◽  
Advisory Board ◽  
Employment Equity ◽  
Advisory Committees ◽  
Equity Ownership ◽  
Refractory Aml

Introduction The infiltration of immune cells into tumors has been associated with therapeutic effects in preclinical models and patients with cancer. In AML, we have previously reported that immune infiltrated TME is predictive of failure to cytotoxic chemotherapy, but associated with response to immunotherapy, specifically FLZ (Uy ASH 2018, Rutella ASH 2018). Furthermore, FLZ also affects immune infiltration in the TME (Rutella ASH 2018). NK cells play an important role in AML control (Ruggieri Science 2012). FLZ (MGD006/S80880) is a humanized DART® molecule that bridges CD123 on AML with CD3 on T cells and mediates anticancer activity via T-cell activation and cytolytic activity against the bound cancer cell. While this is well described in vitro, little evidence of this interaction is available in vivo. Methods Patients (pts) were treated on the recommended phase 2 dose (RP2D) of FLZ (multi-step lead-in dose followed by 500ng/kg/day, in 28-day cycles). We studied the bone marrow (BM) tissue samples for 6 primary refractory pts at baseline and after treatment. Response assessment was performed at day 25±3 days of each cycle. Serial BM samples were evaluated using 2 different staining panels (PD-L1, FoxP3, CD8, CD3, CD103 / CD123, CD3, CD57, CD16) on consecutive slides. Slides were stained using a Leica BondRx autostainer and fluorescence imaged using a Polaris Vectra 3 and analyzed using inForm software. A density-based clustering algorithm developed and run in QuPath was used to quantify CD3+ T cell clusters. Results Six pts with primary refractory AML were included in this report. Pts were heavily pretreated (median prior lines of therapy was 3, range 2-9), and had adverse cytogenetic risk (ELN 2017). Three pts had a complete remission (CR) after 1 cycle of therapy (CR, CRh, CRi), two went on the receive allogeneic stem cell transplant (HSCT). In baseline BM samples, CD3 and CD8 cell infiltrates were higher in CR vs non-responders (CD3+ 18.3% ±6.9 vs 9.3% ±1.8; CD8+ 9.4% ±3.5 vs 4.8% ±1.2; mean±SEM). Two of the three CR patients, who underwent HSCT, developed clusters (Figure 1) in their on-treatment biopsies with 65 and 22 clusters of an average of 34 and 17 T cells per cluster, respectively. All clusters in CR pts were found on or adjacent to CD123+ cells. The BM biopsy of the CR pt with no detected clusters had no unequivocal evidence of residual/recurrent leukemic blasts. This pt had their dose interrupted early due to non-treatment related AE (infectious complication) and did not receive a full cycle of treatment; the response was transient and the pt relapsed shortly thereafter. NK cells (CD57+CD16+) were increased in post treatment biopsies of CR vs non-responders (0.93 ±0.31 vs 0.27 ±0.13; mean±SEM) with the largest fold increase in CR (28 vs 9). Lastly, post treatment biopsy PD-L1 expression was higher in non-responders than CR (23% vs 16%) with non-responders exhibiting the largest fold change in total PD-L1+ cells (10.9 vs 2.2). Summary Consistent with its proposed mechanism of action, these data highlight for the first time, the dynamic induction of an increase in T-cell infiltration, and clustering around CD123 AML cells in the bone marrow microenvironment of two AML patients that responded to FLZ. In pts with resistance to FLZ (non-responders) PD-L1 induction was significantly higher indicating that in some pts treatment with sequential check point inhibitor could obviate this mechanism of resistance A trial combining FLZ with sequential administration of a PD-1 inhibitor (MGA012) is currently recruiting pts. Figure 1. Baseline and on-treatment IHC of BM biopsies of a FLZ-treated CR pt showing cluster formation following treatment. Disclosures Bifulco: Ventana: Other: advisory board; PrimeVax: Equity Ownership, Other: ScientificBoard; BMS: Other: Advisory Board; Providnece: Patents & Royalties: Imaging processing; Halio Dx: Other: advisory board. Wigginton:macrogenics: Employment, Equity Ownership; western oncolytics: Consultancy, Other: consultancy. Muth:MacroGenics, Inc.: Employment, Equity Ownership. Davidson-Moncada:MacroGenics, Inc.: Employment, Equity Ownership. Fox:Akoya: Research Funding; Bristol Myers Squibb: Research Funding; Definiens: Membership on an entity's Board of Directors or advisory committees; Macrogenics: Research Funding; Ultivue: Membership on an entity's Board of Directors or advisory committees.

scholarly journals CAR T Cell Therapy Targeting G Protein-Coupled Receptor Class C Group 5 Member D (GPRC5D), a Novel Target for the Immunotherapy of Multiple Myeloma

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 589-589 ◽  
Author(s):  
Eric L. Smith ◽  
Kimberly Harrington ◽  
Mette Staehr ◽  
Reed Masakayan ◽  
Jon Jones ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Research Funding ◽  
Employment Equity ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership ◽  
G Protein Coupled

Abstract Early clinical results using BCMA targeted CAR T cell therapies for advanced multiple myeloma (MM) have shown promise. However, BCMA expression can be variable, and BCMA downregulation has been correlated with relapse (Brudno J. JCO. 2018; Cohen A. ASH. 2017). Targeting multiple antigens may enhance response durability. We report that the orphan seven transmembrane G protein coupled receptor, GPRC5D, is an attractive additional target for CAR T cell therapy of MM. GPRC5D mRNA expression was previously identified in bone marrow cells from patients with MM; however its protein expression could not be detected with available FACS reagents (Frigyesi I. Blood. 2014). We evaluated 83 primary marrow samples by quantitative immunofluorescence (Q-IF) for CD138, BCMA, and GPRC5D. In 98% of the samples, CD138+ cells expressed surface GPRC5D. In most samples, the majority of CD138+ cells expressed both BCMA and GPRC5D, however, in several cases the dominant CD138+ population expressed only BCMA or GPRC5D, with GPRC5D expression independent of BCMA across samples (R2=0.156; Figure 1). The potential for "on target/off tumor" binding by targeting GPRC5D was evaluated by screening 30 essential normal tissue types by IHC (n=3 donors/type) followed by validation of any positive findings by RNA in situ hybridization and quantitative PCR. Results in non-plasma cell normal tissue were consistent with prior reports of GPRC5D off target expression restricted to cells from the hair follicle, a potentially immune privileged site. We developed GPRC5D-targeted CARs considering immunogenicity, spacer length, and tonic signaling. To minimize potential anti-CAR immunity, a human B cell-derived phage display library was screened. Seven diverse and highly specific human single chain variable fragments (scFvs) were identified. 42 CARs were derived from the 7 scFvs by modifying scFv orientation (VH/VL; VL/VH) and incorporating a short, medium, or long IgG4 based spacer. To monitor CAR-mediated signaling, we transduced each CAR into a Jurkat reporter line with RFP inserted in-frame, downstream of endogenous NR4A1 (Nur77). Nur77 expression is an immediate-early, specific marker of CD3z signaling (Ashouri J. J Immunol. 2017). Using this reporter, we observed that (1) a long spacer provided enhanced antigen-dependent activation across all anti-GPRC5D CARs; and (2) the use of different scFvs resulted in vastly different levels of tonic signaling. We selected potential lead and backup constructs and evaluated CAR activity on primary human T cells. When co-cultured specifically with MM cell lines, anti-GPRC5D CAR T cells secreted a polyfunctional cytokine profile, proliferated, and effectively lysed target cells. CD138+/CD38hi primary MM bone marrow aspirate cells were also specifically lysed. In vivo efficacy of GPRC5D-targeted CAR T cells was evaluated in NSG mice engrafted with a human MM cell line (ffLuc+) bone marrow xenograft. Donor T cells were gene-modified to express anti-GPRC5D CARs with either a 4-1BB or a CD28 co-stimulatory domain and membrane-anchored Gaussia luciferase (GLuc). Compared to control CAR T cells specific for an irrelevant target, anti-GPRC5D CAR T cells with either co-stimulatory domain proliferated and homed to the site of MM (Gluc imaging), eradicated MM xenograft (ffLuc imaging), and increased survival (Figure 2). One scFv that was highly functional in our GPRC5D CAR screen was evaluated for off-target binding against either >200 G protein-coupled receptors (cell based), or >4000 human transmembrane proteins (scFv-Fc based), and demonstrated binding only to GPRC5D. Studies with murine and cynomolgus cross-reactive GPRC5D targeting CARs did not show signs of alopecia or other unexpected toxicity in either species. In a murine model of post-BCMA CAR T cell treated antigen escape (CRISPR BCMA KO of a subpopulation of MM cells), anti-GPRC5D CAR T cells rescue BCMA- relapse. These results indicate that GPRC5D will be an important target for the immunotherapy of MM. We are translating this 4-1BB-containing, human-derived, GPRC5D-targeted CAR construct to the clinic. Disclosures Smith: Celgene: Consultancy, Patents & Royalties: CAR T cell therapies for MM, Research Funding. Harrington:Juno Therapeutics, a Celgene Company: Employment, Equity Ownership. Masakayan:Agentus Inc: Employment. Jones:Juno Therapeutics, a Celgene Company: Employment, Equity Ownership. Long:Juno Therapeutics, a Celgene Company: Employment, Equity Ownership. Ghoddusi:Juno Therapeutics, a Celgene Company: Employment, Equity Ownership. Do:Juno Therapeutics, a Celgene Company: Employment, Equity Ownership. Pham:Juno Therapeutics, a Celgene Company: Employment, Equity Ownership. Wang:Eureka Therapeutics: Employment, Equity Ownership. Liu:Eureka Therapeutics, Inc.: Employment, Equity Ownership. Xu:Eureka Therapeutics: Employment, Equity Ownership. Riviere:Juno Therapeutics, a Celgene Company: Membership on an entity's Board of Directors or advisory committees, Research Funding; Fate Therapeutics Inc.: Research Funding. Liu:Eureka Therapeutics, Inc.: Employment, Equity Ownership. Sather:Juno Therapeutics, a Celgene Company: Employment, Equity Ownership. Brentjens:Juno Therapeutics, a Celgene Company: Consultancy, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.

scholarly journals Simultaneous Targeting of CD19 and CD22: Phase I Study of AUTO3, a Bicistronic Chimeric Antigen Receptor (CAR) T-Cell Therapy, in Pediatric Patients with Relapsed/Refractory B-Cell Acute Lymphoblastic Leukemia (r/r B-ALL): Amelia Study

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 279-279 ◽  
Author(s):  
Persis J Amrolia ◽  
Robert Wynn ◽  
Rachael Hough ◽  
Ajay Vora ◽  
Denise Bonney ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Phase I ◽  
Research Funding ◽  
Advisory Board ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T ◽  
Equity Ownership

Abstract Introduction CAR T-cell therapies directed against CD19 or CD22 antigens have shown significant activity in pediatric patients with r/r B-ALL. Whilst complete response (CR) rates of 70‒90% have been observed, relapse due to target antigen downregulation or loss is the major cause of treatment failure. This Phase I/II study evaluates the safety and efficacy of AUTO3, a CAR T-cell therapy designed to target CD19 and CD22 simultaneously in order to reduce the likelihood of relapse due to antigen loss. Methods & Patients We constructed a novel bicistronic retroviral vector encoding both an anti-CD19 CAR and an anti-CD22 CAR. Antigen binding domains were humanized and both CARs are in "2nd generation" format (incorporating an OX40 co-stimulatory domain for the CD19 CAR and a 41BB for the CD22 CAR). The performance of the CD22 CAR was optimized by incorporating a novel pentameric spacer. The cell product was manufactured on a semi-automated and closed process using CliniMACS® Prodigy (Miltenyi Biotec). Patients (1‒24 years of age) with high risk relapse (IBFM criteria) or relapse post-allogeneic stem cell transplant (SCT), adequate performance score/organ function, and an absolute lymphocyte count ≥0.5 x 109/L are eligible. Patients with CNS 3 disease, active graft versus host disease, and clinically significant infection or serious toxicity from prior CAR T-cell are excluded. Patients receive lymphodepletion with 30 mg/m2/day fludarabine x 4 days and 500 mg/m2/day cyclophosphamide x 2 days prior to AUTO3 infusion. Three dose levels are being explored (1 x 106, 3 x 106, and 5 x 106 transduced CAR+ T cells/kg) and CAR T cells are infused as a single (for <25% blasts) or split (for >25% blasts) dose based on leukemia burden. Bridging therapy is allowed during the manufacturing period. The primary endpoint of Phase I is the frequency of dose-limiting toxicities (DLTs) and key secondary endpoints include proportion of patients achieving a morphological/minimal residual disease (MRD) negative CR, disease-free survival, overall survival, as well as biomarker endpoints including AUTO3 levels and persistence in blood and bone marrow. Results As of the data cut-off date (July 16, 2018), 9 patients have been enrolled and 8 have received AUTO3. It was possible to generate a product in all patients and the median transduction efficiency was 16% (range 9‒34%). Median age was 7.5 years (range 4‒16 years) and 5 (63%) patients had prior SCT. One patient (13%) had prior anti-CD19 CAR-T cells and blinatumomab. The disease burden at Day ‒7 ranged from 0% to 90% leukemic blasts. Eight patients had a minimum of 4 weeks' follow up and were evaluable for safety and efficacy analysis. Three patients received ≤1 × 106 CAR T cells/kg as single dose, 1 patient received 2 × 106/kg as split dose, and 4 received 3 × 106 CAR cells/kg (3 single infusions, 1 split). No AUTO3 related deaths and no DLTs were observed. The most common grade (Gr) ≥3 adverse events were neutropenia (63%), febrile neutropenia (50%), pyrexia (25%), and anemia (25%). Five patients (63%) had Gr 1 cytokine release syndrome (CRS); no Gr 2 or higher CRS was seen. Five patients (63%) experienced neurotoxicity: 4 had Gr 1 and 1 patient (13%) had Gr 3 encephalopathy that was considered likely related to prior intrathecal methotrexate. No patients required ICU admission. Six of 8 patients achieved MRD negative CR, giving an objective response rate of 75% (95% CI 34.9‒96.8%) at 1 month. In patients treated at doses <3 x 106/kg, 3 responded but subsequently relapsed. Importantly, no loss of CD19 or CD22 was noted in patients that relapsed. All 4 patients treated at the higher dose of 3 × 106 CAR T cells/kg had an MRD negative CR with ongoing remission and B-cell aplasia, with the longest follow up of 4 months. CAR T-cell expansion was enhanced in patients receiving 3 x 106/kg (median 79,282 copies/µg DNA in blood at peak) compared to those receiving lower doses (median 10,243 copies/µg DNA). Conclusion This interim data analysis demonstrates for the first time the feasibility and safety of simultaneous targeting of CD19 and CD22 with AUTO3. Promising efficacy was demonstrated at a dose level of 3 × 106 CAR T cells/kg, as 4/4 patients achieved MRD complete remission with no antigen negative escape at this early stage. The study continues to enrol and updated follow up and additional patient data at higher dose levels, as well as cellular kinetics and additional biomarker analysis, will be presented. Disclosures Wynn: Orchard SAB: Membership on an entity's Board of Directors or advisory committees; Orchard Therapeutics: Equity Ownership; Chimerix: Research Funding; Genzyme: Honoraria; Bluebird Bio: Consultancy; Orchard Therapeutics: Consultancy; Chimerix: Consultancy. Hough:University College London Hospital's NHS Foundation Trust: Employment. Vora:Amgen: Other: Advisory board; Medac: Other: Advisory board; Novartis: Other: Advisory board; Pfizer: Other: Advisory board; Jazz: Other: Advisory board. Veys:Servier: Research Funding; Pfizer: Honoraria; Novartis: Honoraria. Chiesa:Gilead: Consultancy; Bluebird Bio: Consultancy. Al-Hajj:Autolus Ltd: Employment; Autolus Ltd: Equity Ownership. Cordoba:Autolus Ltd: Employment; Autolus Ltd: Equity Ownership; Autolus Ltd: Patents & Royalties. Onuoha:Autolus Ltd: Employment, Equity Ownership, Patents & Royalties. Kotsopoulou:Autolus Ltd: Equity Ownership; Autolus Ltd: Employment. Khokhar:Autolus Ltd: Employment; Autolus Ltd: Equity Ownership. Pule:Autolus Ltd: Employment, Equity Ownership, Other: Salary contribution paid for by Autolus, Research Funding; University College London: Patents & Royalties: Patent with rights to Royalty share through UCL. Peddareddigari:Autolus Therapeutics plc: Equity Ownership; Autolus Therapeutics plc: Patents & Royalties; Autolus Therapeutics plc: Employment.

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