Academic, Phase I/II Trial on T Cells Expressing a Second Generation, CD19-Specific Chimeric Antigen Receptor (CAR) and Inducible Caspase 9 Safety Switch for the Treatment of B-Cell Precursor Acute Lymphoblastic Leukemia (BCP-ALL) and B-Cell Non-Hodgkin Lymphoma (B-NHL) in Children

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1341-1341
Author(s):  
Francesca Del Bufalo ◽  
Concetta Quintarelli ◽  
Biagio De Angelis ◽  
Ignazio Caruana ◽  
Matilde Sinibaldi ◽  
...  

Survival rates of children with relapsed/refractory (r/r) BCP-ALL remain unsatisfactory and little progress has been made in the past 2 decades. Similarly, relapse of childhood B-NHL is usually associated with an aggressive disease and poor outcomes. Targeted immunotherapy with T-cells genetically modified to express a CD19-directed CAR showed an unprecedented antitumor efficacy, leading to the recent FDA and EMA approval of two CD19-CAR products for treatment of BCP-ALL and B-NHL. Relevant toxicities have, however, been reported, mainly related to the development of severe Cytokine Release Syndrome (CRS) and/or of neurotoxicity. At Ospedale Pediatrico Bambino Gesù (OPBG) in Rome, we developed a clinical-grade, 2nd generation, CD19-specific CAR construct, including 4.1bb as costimulatory domain and the inducible caspase-9 safety switch (iC9-CD19-CAR), vehiculated by a retroviral vector, to conduct an academic, phase I/II clinical trial in patients (age 1-25 yrs) affected by BCP-ALL or B-NHL. We now report on the results of the phase I and of the first 8 patients treated in the phase II portion of the study, in terms of feasibility, toxicity, maximum tolerated/recommended dose (MTD/RD) and data on response rate and biological correlates. The phase I, dose-escalation portion of the study included 3 dose levels (DL), namely: DL1, 0.5×106; DL2, 1.5×106; DL3, 3.0×106 CAR+ T cells per kg of recipient body weight. In the phase II portion, patients were treated at the RD identified in the phase I, namely 3.0×106 CAR+cells/kg. All patients received a lymphodepleting regimen consisting of fludarabine and cyclophosphamide for 3 days and iC9-CD19-CAR T cells were subsequently administered as single infusion. Patients were monitored for toxicity, expansion and persistence of iC9-CD19-CAR T cells. Seventeen children were enrolled into the trial and received iC9-CD19-CAR T cells between January 2018 and June 2019. Data were analyzed as of July 20, 2019. The characteristics of the patients are detailed in table 1. The designed dose concentration was successfully produced for all the enrolled patients and we did not observe any production failure. The median transduction rate in the drug product was 54% (range 21-73), while the median vector copy number was 3.8 (range 2.8-6.2). During the phase I portion of the study, no dose limiting toxicities (DLTs) have been recorded, defining the MTD as 3.0×106 CAR+ T cells per kg of recipient body weight. The treatment was overall tolerated and all the toxicities were reversible, the most severe being grade 3-4 neutropenia, thrombocytopenia and/or anemia, occurring in 16/17 (94.1%) patients; in 13/16 patients (81.2%) the hematological toxicity developed before the infusion and persisted after the administration of CAR T cells. Cytokine release syndrome (CRS) occurred in 10/17 patients (58.8%) and was overall moderate, reaching grade 3 (Lee criteria) in one patient only. Notably, none of the patients developed neurotoxicity and no activation of the safety switch was required. All patients were assessed for response at 4 weeks from iC9-CD19-CAR T cell infusion and 13/15 (86.7%) patients with ALL achieved complete remission (CR) with negativity of minimal residual disease (MRD), including 2/3 patients receiving the DL1, 9 patients who had failed a previous allogeneic haematopoietic stem-cell transplantation (HSCT) and 6 patients that had previously received blinatumomab, as CD19-directed immunotherapy. The iC9-CD19-CAR T cells expanded in vivo and were detectable by both flow-cytometry and molecular biology in the blood (Fig.1), bone marrow and cerebrospinal fluid of the responders. One CD19-negative relapse 3 months after infusion was recorded, while 3 additional patients relapsed with CD19+ leukemia blasts. Four patients received HSCT while in CR with MRD negativity because of regrowth of normal CD19+ B cells. The 18-month probability of overall survival for the BCP-ALL cohort is 72.2% (Fig.2). One of the 2 B-NHL patients showed a partial response. Our data indicate that iC9-CD19-CAR T cell in an academic setting is feasible, safe and extremely effective in treating highly resistant/relapsed BCP-ALL. In our trial, no major or life-threatening toxicities were observed and, despite the moderate CRS recorded, high rates of CR were achieved, suggesting that the combination of a retroviral platform and 4.1bb as costimulation is able to mediate a potent antitumor effect Disclosures Merli: Amgen: Honoraria; Novartis: Honoraria; Sobi: Consultancy; Bellicum: Consultancy. Algeri:Bluebird bio: Consultancy, Honoraria; Atara Biotherapeutics: Consultancy, Honoraria; Miltenyi: Honoraria. Locatelli:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bellicum: Consultancy, Membership on an entity's Board of Directors or advisory committees; bluebird bio: Consultancy; Miltenyi: Honoraria; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 226-226 ◽  
Author(s):  
Claire Roddie ◽  
Maeve A O'Reilly ◽  
Maria A V Marzolini ◽  
Leigh Wood ◽  
Juliana Dias Alves Pinto ◽  
...  

Introduction: In adults, prognosis for B-ALL is poor, patients are more vulnerable to CD19 CAR immunotoxicity and there is currently no CD19 CAR therapeutic with acceptable toxicity and durable efficacy. We have developed a novel second generation CD19CAR (CAT-41BBz CAR), with a faster off-rate but equivalent on rate than the FMC63-41BBz CAR (Kd 116 nM vs 0.9 nM, T1/2 9s vs 4.2 hours) designed to result in more physiological T-cell activation, reduce toxicity and improve engraftment. Preliminary paediatric clinical data of this novel CD19 CAR (AUTO1) supports this assertion. We here describe preliminary data from ALLCAR19 (NCT02935257), a multi-centre, Phase I clinical study of AUTO1 as therapy for r/r adult B-ALL. Methods: Manufacturing: AUTO1 utilises non-mobilised autologous leucapheresate. The first 6 trial products were generated using a standard dynal bead/WAVE Bioreactor process and subsequent products using a semi-automated closed process. Study design: ALLCAR19 is a phase I/II study recruiting subjects 16-65y with r/r B ALL. Lymphodepletion with fludarabine (30mg/m2 x3) and cyclophosphamide (60mg/kg x1) is followed by split dose CAR T cell infusion (Day 0: if ≥20% BM blasts, infuse 10 x 106 CAR T cells ; if <20% BM blasts, infuse 100 x 106 CAR T cells. Day +9: if no Grade 3-5 CRS/CRES, infuse Dose 2, to a total dose of 410 x 106 CAR T cells). Study endpoints include feasibility of manufacture, grade 3-5 toxicity and remission rates at 1 and 3 months Results: As of 24 July 2019, 16 patients have been leukaphresed, 14 products manufactured (one failed leukaphresis and one currently in manufacture) and 13 patients have received at least 1 dose of AUTO1. Of the 16 patients, median age was 35.5 (range 18-63), 10/16 (63%) had prior blinatumomab or inotuzumab ozogamicin and 12/16 (75%) had prior HSCT. At the time of pre-conditioning, 9/13 (69%) patients were in morphological relapse with >5% leukemic blasts of which 6/13 (46%) had ≥50% blast. 9/13 patients (69%) received the total target split dose of 410 x 106 CAR T cells while 1/13 patients (8%) received a reduced split total dose of 51.3 x 106 CAR T cells due to manufacturing constraints. 3/13 patients (23%) received only a first dose of 10 x 106 CAR T cells. The dose was administered safely to date: No patients experienced ≥Grade 3 CRS (using Lee criteria) and only 1/13 (8%) experienced Grade 3 neurotoxicity (dysphasia) that resolved swiftly with steroids. All patients had robust CAR expansion (median peak expansion 172 CAR/uL blood). Of the 13 patients dosed (1/13 pending 28 day follow up), 10/12 (83%) achieved MRD negative CR at 1 month and all patients had ongoing CAR T cell persistence at last follow up. Two patients experienced CD19 negative relapse (one at M3, one at M6), 1 patient died on D17 before first response evaluation, 1 died in molecular CR from sepsis, and 1 died from persistent disease. Currently, 7/12 remain on study and continue in flow/molecular MRD negative remission with a median follow up of 9.0 months (range 1.2-14.8). Conclusions: AUTO1 delivers excellent early remission rates with initial data showing 83% MRD negative CR and robust CAR expansion and persistence. Despite high tumour burden, the safety profile compares favourably to other CD19 CARs, with no cases of severe CRS and only one case of Gr3 neurotoxicity. This is consistent with experience in the paediatric cohort. Updated results will be presented. Disclosures Roddie: Novartis: Consultancy; Gilead: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau. O'Reilly:Kite Gilead: Honoraria. Farzaneh:Autolus Ltd: Equity Ownership, Research Funding. Linch:Autolus: Membership on an entity's Board of Directors or advisory committees. Pule:Autolus: Membership on an entity's Board of Directors or advisory committees. Peggs:Gilead: Consultancy, Speakers Bureau; Autolus: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 48-48
Author(s):  
Peter Borchmann ◽  
Anja Jühling ◽  
Philipp Gödel ◽  
Hyatt Balke-Want ◽  
Christoph Schmid ◽  
...  

Background CD19 redirected chimeric antigen receptor (CAR) T-cell therapy has proven efficacy in relapsed or chemotherapy-refractory (r/r) aggressive B-cell non-Hodgkin lymphoma (B-NHL). However, targeting a single B-cell antigen leads to selective pressure with potential antigen-escape and subsequent relapse. A tandem CAR targeting CD20 and CD19 (pLTG1497) has been developed to overcome this limitation. Preclinical evaluation showed improved anti-lymphoma activity. Thus, we initiated a first-in-human, phase I clinical study of autologous pLTG1497-transduced CAR T-cells (MB-CART2019.1) in r/r B-NHL patients. Aims In this phase I prospective multi-center trial (NCT03870945) we aimed to evaluate the maximum tolerated dose (MTD) of MB-CART2019.1 in adult patients with CD20 and CD19 positive r/r B-NHL as determined by dose limiting toxicities (DLTs). Methods This was a 6+3 trial design with two predefined dose levels (DL1 1x106 and DL2 2.5x106 CAR T-cells/kg body weight, respectively). Secondary endpoints included adverse events (AEs) and best overall response rate (ORR). Pharmacodynamic assessments included maximum concentration (Cmax) of CAR T-cells, time to peak expansion (tmax), AUC (d0 to d28), and persistence. MB-CART2019.1 was produced by lentiviral transduction of autologous fresh leukapheresis in the closed automated CliniMACS Prodigy® System (Miltenyi Biotec, Bergisch Gladbach, Germany). Re-infusion (Day 0) of fresh MB-CART2019.1 was scheduled 14 days after leukapheresis. Fludarabine/cyclophosphamide lymphodepleting chemotherapy was administered from day -5 to -3. Results A total of 12 patients, 6 per dose level have been enrolled and treated between February and December 2019, 5 female and 7 male patients. Median age was 72 y (range 20, 78 y), with 10 patients >65 y and 8 >70 y. Histologies included aggressive B-NHL (11) and mantle cell lymphoma (1). Five (5) patients had refractory disease at study entry and IPI was ≥3 in 7 patients. Median time from leukapheresis to re-infusion was 14 d (range 13, 14 d). No DLT and no cytokine release syndrome (CRS) or neurotoxicity grade ≥3 were observed. One patient in dose level 1 experienced a grade 5 AE, which was due to disease progression. CRS grade 1 occurred in 3/6 patients on DL1 and DL2 each, and CRS grade 2 in 2 patients on DL2. Tocilizumab was given in 1 patient. Neurotoxicity grade 1 occurred in 1 patient on DL2. The above described CRS and neurotoxicity resolved completely. Mean Cmax of MB-CART2019.1 was 348.3 cells/µl (range 3.9, 830.4 cells/µl) on DL1 and 692 cells/µl (range 5.3, 3147.8 cells/µl) on DL2. Mean tmax was 15.8 d (range 9, 21 d) on DL1 and 11.5 d (range 9, 14 d) on DL2. Mean AUC was 3155 d*cells/µl (DL1) and 4339 d*cells/µl (DL2). Persistence of MB-CART2019.1 was observed in 12/12 patients until data cut-off. Altogether 9/12 patients (ORR 75%) responded to MB-CART2019.1 with 5/12 CRs. In DL1 3/6 patients responded (ORR 50%) and in DL2 6/6 patients (ORR 100%). The 3 patients without response to MB-CART2019.1 had a mean AUC0-28 of 870 d*cells/µl, whereas mean AUC0-28 in 9 responders was 4843 d*cells/µl reflecting the correlation between the pharmacodynamic parameters and the clinical response. Responses are ongoing in 5/9 patients, with a maximum duration of response of 330 days at data cut-off. Summary/Conclusions In this first-in-human dose finding study of MB-CART2019.1 no DLT and no severe (grade ≥3) CRS or neurotoxicity were observed. Feasibility and safety were very good in this cohort of elderly r/r B-NHL patients. The sustained expansion of tandem CAR T-cells was accompanied by efficacy: all patients (6/6) treated on DL2 responded and all 5 patients with CR (5/5) are in ongoing remission by the time of this report. Based on the promising risk-to-benefit ratio observed in our study, evaluation of MB-CART2019.1 at a dose of 2.5x106/kg body weight in clinical phase II and phase III trials for patients with relapsed aggressive B-NHL is underway. Disclosures Borchmann: Miltenyi Biotec B.V. & Co. KG: Honoraria. Balke-Want:Miltenyi Biotec B.V. & Co. KG: Honoraria. Ayuk:Celgene: Consultancy, Honoraria; Kite/Gilead: Honoraria; Therakos/Mallinckrodt: Honoraria, Research Funding; Neovii: Research Funding; Novartis: Honoraria. Holtkamp:Miltenyi Biomedicine GmbH: Current Employment. Preussner:Miltenyi Biomedicine GmbH: Ended employment in the past 24 months. Zadoyan:Miltenyi Biomedicine GmbH: Current Employment. Hanssens:Miltenyi Biomedicine GmbH: Current Employment. Kaiser:Miltenyi Biotec B.V. & Co. KG: Current Employment. Jurk:Miltenyi Biotec B.V. & Co. KG: Current Employment. Bürger:Miltenyi Biotec B.V. & Co. KG: Current Employment. Schneider:Lentigen Technology Inc., A Miltenyi Company: Current Employment, Patents & Royalties. Dropulic:Lentigen Technology Inc., A Miltenyi Company: Current Employment. Overstijns:Miltenyi Biomedicine GmbH: Current Employment, Membership on an entity's Board of Directors or advisory committees; Miltenyi Biotec B.V. & Co. KG: Current Employment, Membership on an entity's Board of Directors or advisory committees. Scheid:Novartis: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; BMS: Honoraria; Amgen: Honoraria; Takeda: Honoraria, Research Funding. Holtick:Miltenyi Biotec B.V. & Co. KG: Honoraria. Miltenyi:Miltenyi Biomedicine GmbH: Current Employment, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Lentigen Technology Inc., A Miltenyi Company: Current Employment, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Miltenyi Biotec B.V. & Co. KG: Current Employment, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 22-23
Author(s):  
Pinar Ataca Atilla ◽  
Mary K McKenna ◽  
Norihiro Watanabe ◽  
Maksim Mamonkin ◽  
Malcolm K. Brenner ◽  
...  

Introduction: Efforts to safely and effectively treat acute myeloid leukemia (AML) by targeting a single leukemia associated antigen with chimeric antigen receptor T (CAR T) cells have had limited success. We determined whether combinatorial expression of chimeric antigen receptors directed to two different AML associated antigens would augment tumor eradication and prevent relapse in targets with heterogeneous expression of myeloid antigens. Methods: We generated CD123 and CD33 targeting CARs; each containing a 4-1BBz or CD28z endodomain. We analyzed the anti-tumor activity of T cells expressing each CAR alone or in co-transduction with a CLL-1 CAR with CD28z endodomain and CD8 hinge previously optimized for use in our open CAR-T cell trial for AML (NCT04219163). We analyzed CAR-T cell phenotype, expansion and transduction efficacy by flow cytometry and assessed function by in vitro and in vivo activity against AML cell lines expressing high, intermediate or low levels of the target antigens (Molm 13= CD123 high, CD33 high, CLL-1 intermediate, KG1a= CD123 low, CD33 low, CLL-1 low and HL60= CD123 low, CD33 intermediate, CLL-1 intermediate/high) For in vivo studies we used NOD.SCID IL-2Rg-/-3/GM/SF (NSGS) mice with established leukemia, determining antitumor activity by bioluminescence imaging. Results: We obtained high levels of gene transfer and expression with both single (CD33.4-1BBʓ, CD123.4-1BBʓ, CD33.CD28ʓ, CD123.CD28ʓ, CLL-1 CAR) and double transduction CD33/CD123.4-1BBʓ or CD33/CD123.CD28ʓ) although single-transductants had marginally higher total CAR expression of 70%-80% versus 60-70% after co-transduction. Constructs containing CD28 co-stimulatory domain exhibited rapid expansion with elevated peak levels compared to 41BB co-stim domain irrespective of the CAR specificity. (p<0.001) (Fig 1a). In 72h co-culture assays, we found consistently improved anti-tumor activity by CAR Ts expressing CLL-1 in combination either with CD33 or with CD123 compared to T cells expressing CLL-1 CAR alone. The benefit of dual expression was most evident when the target cell line expressed low levels of one or both target antigens (e.g. KG1a) (Fig 1b) (P<0.001). No antigen escape was detected in residual tumor. Mechanistically, dual expression was associated with higher pCD3ʓ levels compared to single CAR T cells on exposure to any given tumor (Fig 1c). Increased pCD3ʓ levels were in turn associated with augmented CAR-T degranulation (assessed by CD107a expression) in both CD4 and CD8 T cell populations and with increased TNFα and IFNɣ production (p<0.001 Fig 1d). In vivo, combinatorial targeting with CD123/CD33.CD28ʓ and CLL-1 CAR T cells improved tumor control and animal survival in lines (KG1a, MOLM13 and HL60) expressing diverse levels of the target antigens (Fig 2). Conclusion: Combinatorial targeting of T cells with CD33 or CD123.CD28z CARs and CLL-1-CAR improves CAR T cell activation associated with superior recruitment/phosphorylation of CD3ʓ, producing enhanced effector function and tumor control. The events that lead to increased pCD3ʓ after antigen engagement in the dual transduced cells may in part be due to an overall increase in CAR expression but may also reflect superior CAR recruitment after antigen engagement. We are now comparing the formation, structure, and stability of immune synapses in single and dual targeting CARs for AML. Disclosures Brenner: Walking Fish: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Tumstone: Membership on an entity's Board of Directors or advisory committees; Tessa Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: Founder; Maker Therapeutics: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Other: Founder; Memmgen: Membership on an entity's Board of Directors or advisory committees; Allogene: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees. Atilla:Bluebird Bio: Membership on an entity's Board of Directors or advisory committees; Tumstone: Membership on an entity's Board of Directors or advisory committees; Tessa Therapeutics: Membership on an entity's Board of Directors or advisory committees, Other: founder; Marker Therapeuticsa: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Other: Founder, Patents & Royalties; Allogene: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Walking Fish: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Memgen: Membership on an entity's Board of Directors or advisory committees; KUUR: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 776-776
Author(s):  
Claire Roddie ◽  
Maeve A O'Reilly ◽  
Maria A V Marzolini ◽  
Leigh Wood ◽  
Juliana Dias Alves Pinto ◽  
...  

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


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 779-779 ◽  
Author(s):  
Zinaida Good ◽  
Jay Y. Spiegel ◽  
Bita Sahaf ◽  
Meena B. Malipatlolla ◽  
Matthew J. Frank ◽  
...  

Axicabtagene ciloleucel (Axi-cel) is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for the treatment of relapsed or refractory diffuse large B-cell lymphoma (r/r DLBCL). Long-term analysis of the ZUMA-1 phase 1-2 clinical trial showed that ~40% of Axi-cel patients remained progression-free at 2 years (Locke et al., Lancet Oncology 2019). Those patients who achieved a complete response (CR) at 6 months generally remained progression-free long-term. The biological basis for achieving a durable CR in patients receiving Axi-cel remains poorly understood. Here, we sought to identify CAR T-cell intrinsic features associated with CR at 6 months in DLBCL patients receiving commercial Axi-cel at our institution. Using mass cytometry, we assessed expression of 33 surface or intracellular proteins relevant to T-cell function on blood collected before CAR T cell infusion, on day 7 (peak expansion), and on day 21 (late expansion) post-infusion. To identify cell features that distinguish patients with durable CR (n = 11) from those who developed progressive disease (PD, n = 14) by 6 months following Axi-cel infusion, we performed differential abundance analysis of multiparametric protein expression on CAR T cells. This unsupervised analysis identified populations on day 7 associated with persistent CR or PD at 6 months. Using 10-fold cross-validation, we next fitted a least absolute shrinkage and selection operator (lasso) model that identified two clusters of CD4+ CAR T cells on day 7 as potentially predictive of clinical outcome. The first cluster identified by our model was associated with CR at 6 months and had high expression of CD45RO, CD57, PD1, and T-bet transcription factor. Analysis of protein co-expression in this cluster enabled us to define a simple gating scheme based on high expression of CD57 and T-bet, which captured a population of CD4+ CAR T cells on day 7 with greater expansion in patients experiencing a durable CR (mean±s.e.m. CR: 26.13%±2.59%, PD: 10.99%±2.53%, P = 0.0014). In contrast, the second cluster was associated with PD at 6 months and had high expression of CD25, TIGIT, and Helios transcription factor with no CD57. A CD57-negative Helios-positive gate captured a population of CD4+ CAR T cells was enriched on day 7 in patients who experienced progression (CR: 9.75%±2.70%, PD: 20.93%±3.70%, P = 0.016). Co-expression of CD4, CD25, and Helios on these CAR T cells highlights their similarity to regulatory T cells, which could provide a basis for their detrimental effects. In this exploratory analysis of 25 patients treated with Axi-cel, we identified two populations of CD4+ CAR T cells on day 7 that were highly associated with clinical outcome at 6 months. Ongoing analyses are underway to fully characterize this dataset, to explore the biological activity of the populations identified, and to assess the presence of other populations that may be associated with CAR-T expansion or neurotoxicity. This work demonstrates how multidimensional correlative studies can enhance our understanding of CAR T-cell biology and uncover populations associated with clinical outcome in CAR T cell therapies. This work was supported by the Parker Institute for Cancer Immunotherapy. Figure Disclosures Muffly: Pfizer: Consultancy; Adaptive: Research Funding; KITE: Consultancy. Miklos:Celgene: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Kite-Gilead: Membership on an entity's Board of Directors or advisory committees, Research Funding; AlloGene: Membership on an entity's Board of Directors or advisory committees; Precision Bioscience: Membership on an entity's Board of Directors or advisory committees; Miltenyi Biotech: Membership on an entity's Board of Directors or advisory committees; Becton Dickinson: Research Funding; Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Juno: Membership on an entity's Board of Directors or advisory committees. Mackall:Vor: Other: Scientific Advisory Board; Roche: Other: Scientific Advisory Board; Adaptimmune LLC: Other: Scientific Advisory Board; Glaxo-Smith-Kline: Other: Scientific Advisory Board; Allogene: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Apricity Health: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Unum Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Obsidian: Research Funding; Lyell: Consultancy, Equity Ownership, Other: Founder, Research Funding; Nektar: Other: Scientific Advisory Board; PACT: Other: Scientific Advisory Board; Bryologyx: Other: Scientific Advisory Board.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 196-196
Author(s):  
Bishwas Shrestha ◽  
Kelly Walton ◽  
Jordan Reff ◽  
Elizabeth M. Sagatys ◽  
Nhan Tu ◽  
...  

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


2018 ◽  
Vol 10 (11) ◽  
Author(s):  
Anett Pfeiffer ◽  
Frederic B Thalheimer ◽  
Sylvia Hartmann ◽  
Annika M Frank ◽  
Ruben R Bender ◽  
...  

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 11-12
Author(s):  
Felix Korell ◽  
Thomas Luft ◽  
Michael Schmitt ◽  
Sascha Dietrich ◽  
Anita Schmitt ◽  
...  

BACKGROUND: In a previous study we have shown that CD19-directed chimeric antigen receptor (CAR)-T cells do not appear to be inferior to alloHCT when used as standard cellular immunotherapy (CI) for patients with multiply r/r LBCL (EBMT 2020). The purpose of the present follow-up analysis was to further compare the risk profile of the 2 cohorts by applying the EASIX score (lactate dehydrogenase (U/L) × creatinine (mg/dL)/thrombocytes (109 cells per L)), and to assess if EASIX could be used as outcome predictor in patients with r/r LBCL undergoing CAR-T and alloHCT, respectively. METHODS: Eligible were all patients referred to our institution with relapsed/refractory (R/R) DLBCL and a tumor board decision recommending treatment with CAR-T cells between 07/2018 and 02/2020 and those recommending allogeneic donor search between 2004 and 2019. Patients with DLBCL transformed from CLL were excluded. EASIX was evaluated retrospectively using uni- and multivariable analyses (with regards to age, gender and number of failed therapy lines) and mortality using Cox regression analyses. RESULTS: 41 patients intended for CAR-T cells and 60 patients intended for alloHCT were included. In both cohorts nearly all patients had active disease at indication. Cohorts were comparable for sex, time from diagnosis, ZUMA1 eligibility, and PS, but CAR-T patients tended to be older (median 56 vs 51 years, p=0.093), and had more often primary refractory and bulky disease (p=0.004 and p=0.04, respectively). Median EASIX score across both cohorts was 1.50 (0.27-70.5), with significantly higher scores in the CART group both at indication (EASIX-ind; median 1.79 and 1.22 for CAR-T and alloHCT, respectively, p=0.031) and at conditioning for CI (EASIX-pre, median 2.24 vs 1.26, p=0.005). Median OS from indication was 475d for the CAR-T cohort vs 285d for the alloHCT cohort (p=0.88). On multivariate analysis, EASIX-ind was significantly associated with adverse OS if alloHCT was intended (HR per 2fold increase 1.43, 95%CI 1.08-1.90, p=0.013), but not if CAR-T was intended (HR per 2fold increase 1.16, 95%CI 0.88-1.53, p=0.3). After CI, 12-month estimates for NRM, relapse incidence, PFS, and OS for CAR-T vs alloHCT were 3% vs 21% (p=0.04), 59% vs 44% (p=0.12), 39% vs 33% (p=0.97), and 68% vs 54% (p=0.32). EASIX-pre predicted overall survival (OS) in both CAR-T (HR per 2fold increase 2.11, 95%CI 1.21-3.7, p=0.009) and alloHCT (HR per 2fold increase 3.69, 95%CI 1.54-8.31, p=0.003) cohorts. In the alloHCT group, the EASIX effect was largely driven by higher NRM risk with increasing EASIX-pre, while in the CAR-T group poorer OS with increasing EASIX-pre was largely relapse-related. CONCLUSIONS: In patients undergoing CI for r/r LBCL, EASIX measured prior to conditioning can predict mortality after both CAR-T and alloHCT. If applied already at indication for CI, the predictive capacity of EASIX is weaker and no longer significant if CAR-T is intended. Further studies for validation of this data appear to be warrantable. Disclosures Schmitt: MSD: Membership on an entity's Board of Directors or advisory committees, Other: PI of clinical trials on letermovir; TolerogenixX Ltd: Other: Co-Founder and shareholder; Hexal: Other: Travel grants , Research Funding; Apogenix: Research Funding; Kite: Other: Travel grants, educational activities and conferences; Novartis: Other: educational activities and conferences, Research Funding. Dietrich:Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; KITE: Membership on an entity's Board of Directors or advisory committees. Schmitt:Hexal: Other: Travel grants ; TolerogenixX LtD: Other: Co-founder, Part-time employee ; Therakos/Mallinckrodt: Research Funding; Jazz Pharmaceuticals: Other: Travel grants . Dreger:Neovii: Research Funding; Roche: Consultancy, Speakers Bureau; Riemser: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Janssen: Consultancy; Gilead: Consultancy, Speakers Bureau; AstraZeneca: Consultancy; AbbVie: Consultancy, Speakers Bureau.


Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 742-742 ◽  
Author(s):  
Eric L Smith ◽  
Sham Mailankody ◽  
Arnab Ghosh ◽  
Reed Masakayan ◽  
Mette Staehr ◽  
...  

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.


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