Efficacy and Safety of P-Bcma-101 CAR-T Cells in Patients with Relapsed/Refractory (r/r) Multiple Myeloma (MM)

Abstract P-BCMA-101 is a novel chimeric antigen receptor (CAR)-T cell therapeutic targeting BCMA, which is highly expressed on MM cells. It is designed to increase efficacy while minimizing toxicity through reduced immunogenicity, lack of tonic signaling, a safety switch, and a product comprised predominantly of early memory T cells that are effectively all CAR-positive. Rather than using a traditional antibody-based binder, P-BCMA-101 utilizes an anti-BCMA Centyrin™ fused to a CD3ζ/4-1BB signaling domain. Centyrins are fully human and have high binding affinities, but are smaller, more stable and potentially less immunogenic. P-BCMA-101 is produced using the piggyBac™ (PB) DNA Modification System instead of a viral vector, and requires only plasmid DNA and mRNA. This eliminates the need for virus, is less costly, and produces a purified population of CAR+ cells with a preponderance of the favorable stem cell memory T phenotype (TSCM). The higher cargo capacity permits the incorporation of other genes, a safety switch that allows for rapid depletion of product in vivo if indicated by adverse events, and a selection gene that allows for enrichment of CAR+ cells. These features are predicted to result in a greater therapeutic index. Efficacy of P-BCMA-101 in NSG mice bearing aggressive human MM.1S and p53 -/- MM.1S MM was reported (Hermanson, AACR 2016). Whereas control animals died early, tumor burden was reduced to the limit of detection after P-BCMA-101 treatment, and recurrences were spontaneously re-controlled without re-administration of product. A Phase 1, 3+3 dose escalation trial is being conducted in patients with r/r MM (≥ 3 prior lines, including a proteasome inhibitor and an IMiD, or double refractory) to assess the safety and efficacy of P-BCMA-101 (NCT03288493). No pre-specified level of BCMA expression was required. Patients are apheresed to harvest T cells, P-BCMA-101 is then manufactured and administered to patients as a single intravenous (IV) dose after a standard 3-day cyclophosphamide (300 mg/m2/day) / fludarabine (30 mg/m2/day) conditioning regimen. As of 31Jul18, 12 patients have been treated with 48, 50, 55, 118, 122, 124, 143, 155, 164, 238, 324 and 430 x 106 P-BCMA-101 CAR-T cells in 3 weight-based cohorts. Patients were heavily pre-treated (3-9 prior therapies), 100% had failed IMiDs, proteasome inhibitors and daratumumab, and 64% had high-risk cytogenetics. Nine patients have yet reached their first 2-week response assessment. All patients have shown some improvement in myeloma assessments on study, yet only 1 patient (8%) has developed any cytokine release syndrome (CRS) (limited Grade 2). Of 3 patients in the first cohort 1 attained a PR and 1 with non-secretory disease near CR of her plasmacytomas on PET/CT. Of the subsequent 6 patients, 3 patients have thus far reached a PR, 1 a VGPR, and 1 a sCR. Thus of the yet evaluable patients treated above Cohort 1, the overall response rate (ORR) is 83% (5/6), in spite of only one experiencing CRS. This CRS was scored as Grade 2, based on short-lived fever and hypotension managed with IV fluids and antibiotics, with minimal CRS marker elevations. Likewise, CRS markers were minimally elevated in other patients. The maximal IL-6 level in any patient was 86 pg/mL, which is orders of magnitude lower than levels generally reported in patients experiencing meaningful CRS after treatment with CAR-T products. No patients required treatment with tocilizumab or safety switch activation. There have been no patient deaths, and no neurotoxicity, DLTs or unexpected/off-target toxicities related to treatment. Generally, infusions were well-tolerated, with cytopenias, including transfusion requiring cytopenias and febrile neutropenia, being the most common Grade 3+ adverse events. Consistent with the hypothesis of the early memory phenotype conveying durability, circulating P-BCMA-101 cells were detected in the blood by flow and PCR, peaking at 2-3 weeks, and remaining detectable at the last timepoint tested in all patients (3 patients thus far assessed at 3 months). In conclusion, current clinical trial data in patients with r/r MM support preclinical findings that the novel design of P-BCMA-101 can produce significant efficacy, comparing favorably with other anti-BCMA CAR-T products at similar doses, with notably less CRS and no neurotoxicity, consistent with the hypothesis of an improved therapeutic index. Funding by Poseida Therapeutics and CIRM. Disclosures Gregory: Poseida Therapeutics, Inc.: Research Funding. Cohen:Seattle Genetics: Consultancy; Kite Pharma: Consultancy; Oncopeptides: Consultancy; Poseida Therapeutics, Inc.: Research Funding; GlaxoSmithKline: Consultancy, Research Funding; Bristol Meyers Squibb: Consultancy, Research Funding; Celgene: Consultancy; Janssen: Consultancy; Novartis: Research Funding. Costello:Celgene: Consultancy; Poseida Therapeutics, Inc.: Research Funding; Takeda: Consultancy. Ali:Celgene Inc: Research Funding; Aduro Biotech: Consultancy, Research Funding; Amgen Inc: Consultancy; Juno: Consultancy; Takeda Oncology: Consultancy; Poseida Therapeutics: Research Funding. Berdeja:Genentech: Research Funding; Bluebird: Research Funding; Glenmark: Research Funding; Celgene: Research Funding; Takeda: Research Funding; Teva: Research Funding; Janssen: Research Funding; Sanofi: Research Funding; Novartis: Research Funding; Poseida Therapeutics, Inc.: Research Funding; Bristol-Myers Squibb: Research Funding; Amgen: Research Funding. Ostertag:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Martin:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Shedlock:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Resler:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Spear:Poseida Therapeutics, Inc.: Employment, Equity Ownership. Orlowski:Millenium Pharmaceuticals: Consultancy, Research Funding; Poseida: Research Funding; BioTheryX, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Consultancy; Genentech: Consultancy; Janssen Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Patel:Poseida Therapeutics, Inc.: Research Funding; Takeda: Research Funding; Abbvie: Research Funding; Celgene: Research Funding.

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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 ◽

10.1182/blood.v130.suppl_1.742.742 ◽

2017 ◽

Vol 130 (Suppl_1) ◽

pp. 742-742 ◽

Cited By ~ 1

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.

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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 ◽

10.1182/blood-2019-129562 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 3184-3184 ◽

Cited By ~ 16

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.

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

Blood ◽

10.1182/blood-2018-99-116953 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 488-488 ◽

Cited By ~ 41

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.

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A Phase 2 Multicenter Trial of KTE-C19 (anti-CD19 CAR T Cells) in Patients With Chemorefractory Primary Mediastinal B-Cell Lymphoma (PMBCL) and Transformed Follicular Lymphoma (TFL): Interim Results From ZUMA-1

Blood ◽

10.1182/blood.v128.22.998.998 ◽

2016 ◽

Vol 128 (22) ◽

pp. 998-998 ◽

Cited By ~ 15

Author(s):

Sattva S. Neelapu ◽

Frederick L. Locke ◽

Nancy L Bartlett ◽

Tanya Siddiqi ◽

Caron A. Jacobson ◽

...

Keyword(s):

T Cells ◽

B Cell ◽

Board Of Directors ◽

B Cell Lymphoma ◽

Cell Transplant ◽

Employment Equity ◽

Advisory Committees ◽

Car T Cells ◽

Car T ◽

Equity Ownership

Abstract Background: ZUMA-1 is a phase 1-2 multicenter, open-label study evaluating the safety and efficacy of KTE-C19 in patients with refractory aggressive B-cell non-Hodgkin lymphoma. In phase 1, KTE-C19 demonstrated ongoing complete remissions with a tolerable safety profile (Neelapu, ASCO 2016). The phase 2 portion of the study has 2 cohorts based on tumor type: diffuse large B-cell lymphoma (cohort 1) or PMBCL/TFL (cohort 2). Results from cohort 2 at the time of the first pre-specified interim analysis of ZUMA-1 are presented here. Methods: Patients received KTE-C19 at a target dose of 2 × 106 (minimum 1 × 106) anti-CD19 chimeric antigen receptor (CAR) T cells/kg after a low-dose conditioning chemotherapy regimen of cyclophosphamide (500 mg/m2) and fludarabine (30 mg/m2) daily for 3 days. The primary endpoint was overall remission rate per International Working Group criteria (Cheson, J Clin Oncol2007). Key secondary endpoints include duration of response, incidence of adverse events (AEs), levels of CAR T cells in the blood, and levels of serum cytokines. Key inclusion criteria include ≥ 18 years old, Eastern Cooperative Oncology Group (ECOG) performance status 0-1, and chemorefractory disease defined as progressive disease or stable disease as best response to last line of therapy, or disease progression ≤12 months after autologous stem cell transplant. Patients must have received prior anti-CD20 therapy and an anthracycline-containing regimen. Results: As of June 16, 2016, six patients in cohort 2 were treated with KTE-C19 and had at least 30 days of follow up. The median follow up time was 3.2 months. Fifty percent of patients had PMBCL and 50% had TFL. Median age was 55 years (range, 28-60), 67% were male, 67% ECOG performance status 0, and 50% were refractory to second or greater line of chemotherapy while 50% relapsed after autologous stem cell transplant. The objective response rate was 100%. All patients have ongoing complete remissions. Worst grades 3 and 4 treatment-emergent AEs occurred in 17% and 67% of patients, respectively. There were no grade 5 events. All grade 4 treatment-emergent AEs were cytopenias. KTE-C19-related worst grade 3 and 4 AEs occurred in 50% and 17% of patients, respectively. Patient incidence of any grade/grade 3/grade 4 CRS and neurotoxicity were 100%/0%/0% and 67%/33%/0%, respectively. All KTE-C19-related AEs have resolved. Biomarker endpoints will be presented. Conclusions: KTE-C19 demonstrated early promising activity in patients with refractory PMBCL and TFL. The predominant toxicities of CRS and neurotoxicity were generally reversible. Updated trial results from 11 patients at interim analysis 2 will be presented. Clinical trial: NCT02348216. This study is supported in part by funding from The Leukemia & Lymphoma Society (LLS) Therapy Acceleration Program® Disclosures Locke: Kite: Membership on an entity's Board of Directors or advisory committees. Bartlett:Gilead: Consultancy. 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. . Jacobson:Kite: Membership on an entity's Board of Directors or advisory committees. Westin:ProNAi: Membership on an entity's Board of Directors or advisory committees; Spectrum: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Chugai: Membership on an entity's Board of Directors or advisory committees. Chavez:Janssen: Speakers Bureau. LaCasce:Seattle Genetics: Consultancy; Seattle Genetics: Consultancy; Forty Seven: Consultancy; Forty Seven: Consultancy. Bot:Kite Pharma: Employment, Equity Ownership. Rossi:Kite Pharma: Employment, Equity Ownership. Jiang:Kite Pharma: Employment, Equity Ownership. Aycock:Kite Pharma: Employment, Equity Ownership. Elias:Kite: Employment, Equity Ownership. Wiezorek:Kite Pharma: Employment, Equity Ownership. Go:Kite Pharma: Employment, Equity Ownership.

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Fully Human Bcma Targeted Chimeric Antigen Receptor T Cells Administered in a Defined Composition Demonstrate Potency at Low Doses in Advanced Stage High Risk Multiple Myeloma

Blood ◽

10.1182/blood-2018-99-117729 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1011-1011 ◽

Cited By ~ 39

Author(s):

Damian J. Green ◽

Margot Pont ◽

Blythe Duke Sather ◽

Andrew J. Cowan ◽

Cameron J. Turtle ◽

...

Keyword(s):

T Cells ◽

High Risk ◽

Board Of Directors ◽

Cd4 T Cells ◽

Research Funding ◽

High Sensitivity ◽

Advisory Committees ◽

Car T Cells ◽

Car T ◽

Equity Ownership

Abstract Background: Despite advances in the treatment of multiple myeloma (MM) almost all patients relapse and high risk features continue to portend a short median survival. The adoptive transfer of B-Cell Maturation Antigen (BCMA) chimeric antigen receptor (CAR) T cells is demonstrating early promise in MM, but the durability of response has not been established. The infusion of genetically modified CD8+ and CD4+ T cells of a defined composition facilitates the evaluation of each subset's function and has contributed to reproducible efficacy and safety in clinical trials with CD19-specific CAR T cells. In this phase I first-in-human study employing a human scFv containing BCMA CAR T cell construct, we report rapid and deep objective responses at a low CAR T cell dose level (5 x 107) suggesting that construct specific features and differences in product formulation may substantially impact efficacy. Methods: Eligible patients had relapsed or treatment refractory MM, ≥10% CD138+ bone marrow (BM) plasma cells (PC), and ≥5% BCMA expression by flow cytometry (FC). Patients were stratified by tumor burden (CD138+ IHC) into two cohorts; 10-30% MM cells [cohort A] or >30% BM involvement [cohort B] to facilitate assessment of impact of disease burden on outcome. Eligible patient's CD8+ and CD4+ T cells were isolated via positive selection, enriched separately by immunomagnetic selection and cryopreserved. The CD8+ and CD4+ T cells were stimulated in independent cultures with anti-CD3/anti-CD28 paramagnetic beads and transduced with a 3rd generation lentiviral vector encoding a fully human BCMA scFv and 4-1BB and CD3 zeta signaling domains. After in vitro expansion, the cell product for infusion was formulated in a 1:1 ratio of CD4+:CD8+ BCMA CAR T cells. A truncated non-functional human epidermal growth factor receptor (EGFRt) was encoded in the transgene cassette to identify transduced T cells. Lymphodepleting chemotherapy preceded infusion of EGFRt+ CAR T cells at a starting dose of 5 x 107 EGFRt+ cells (n=5) for each cohort. Results: Seven patients (median age of 63 years; range 49 to 76) with a median of 8 prior regimens (range 6 to 11) have received treatment. The median %PC in BM (IHC) at enrollment was 58% (range 20% to >80%). In cohort B the dose has been escalated to 15 x107 EGFRt+ cells (n=2). All patients (7/7) had at least one high risk cytogenetic feature (17p- [n=4], t(4;14) [n=2], t(14;16) [n=1]), 71% had ≥ 2 high risk cytogenetic features, 71% had prior autologous stem cell transplant, 43% had prior allogeneic transplant, and one patient (14%) had PCL. The median involved free light chain (FLC) at enrollment was 180 mg/dL (range 40.37 to 502.96 mg/dL; n=5) and the median monoclonal protein was 3.8 g/dL (range 1.6 to 6.5 g/dL; n=5). The overall response rate at 28 days was 100%; at this time all evaluable patients (n=6) had no detectable abnormal BM PC clone by both IHC and high sensitivity FC. Within 28 days of treatment the involved FLC was normal or sub-normal in all patients and the M-protein had decreased by a median of 73% (range 56.25 to 83% reduction). BCMA CAR T cells remained detectable 90 days after infusion, representing up to 41.5 percent of CD3+ lymphocytes. All patients were surviving at a median of 16 wks (range 2 to 26 wks). One patient relapsed (day +60) and a tumor biopsy demonstrated the presence of a BCMAneg PC population, a 70% reduction in the fraction of MM cells expressing BCMA by FC and a fivefold reduction in BCMA antigen binding capacity on MM cells retaining target expression. A cytotoxic T lymphocyte response to the trans-gene product was not identified in this patient. No dose limiting toxicity has been observed during the 28 day monitoring window and treatment has been well tolerated with no cytokine release syndrome (CRS) observed in one patient and grade 2 or lower CRS (Lee Criteria) for all other patients. No neurological toxicity has been observed. Conclusion: BCMA CAR T cells harboring a fully human scFv with a defined composition of CD4+:CD8+ T cells were well tolerated and potent, demonstrating complete objective responses in heavily pretreated high-risk MM at total cell doses as low as 5 x 107. Next generation sequencing and multiparameter high sensitivity flow cytometry studies to evaluate for minimal residual disease are ongoing. Peak expansion levels and persistence of the CAR T cells are being monitored with early findings suggesting an absence of transgene product immunogenicity. Disclosures Green: Juno Therapeutics: Patents & Royalties, Research Funding. Sather:Juno Therapeutics: Employment. Cowan:Janssen: Research Funding; Abbvie: Research Funding; Juno Therapeutics: Research Funding; Sanofi: Research Funding. Turtle:Caribou Biosciences: Consultancy; Gilead: Consultancy; Bluebird Bio: Consultancy; Precision Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Aptevo: Consultancy; Eureka Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Nektar Therapeutics: Consultancy, Research Funding; Juno Therapeutics / Celgene: Consultancy, Patents & Royalties, Research Funding; Adaptive Biotechnologies: Consultancy. Till:Mustang Bio: Patents & Royalties, Research Funding. Becker:GlycoMimetics: Research Funding. Blake:Celgene: Employment, Equity Ownership. Works:Juno Therapeutics: Employment. Maloney:GlaxoSmithKline: Research Funding; Juno Therapeutics: Research Funding; Seattle Genetics: Honoraria; Roche/Genentech: Honoraria; Janssen Scientific Affairs: Honoraria. Riddell:Cell Medica: Membership on an entity's Board of Directors or advisory committees; Juno Therapeutics: Equity Ownership, Patents & Royalties, Research Funding; Adaptive Biotechnologies: Consultancy; NOHLA: Consultancy.

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Safety and Anti-Tumor Activity of CD5 CAR T-Cells in Patients with Relapsed/Refractory T-Cell Malignancies

Blood ◽

10.1182/blood-2019-129559 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 199-199 ◽

Cited By ~ 8

Author(s):

LaQuisa C. Hill ◽

Rayne H. Rouce ◽

Tyler S. Smith ◽

Lina Yang ◽

Madhuwanti Srinivasan ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Board Of Directors ◽

Research Funding ◽

Advisory Committees ◽

Car T Cells ◽

Car T Cell ◽

Car T ◽

Equity Ownership ◽

T Cell Malignancies

Introduction: We describe a Phase I dose escalation study (NCT03081910) of autologous CD5-directed chimeric antigen receptor T cell (CD5 CAR T) therapy for relapsed or refractory (r/r) T-cell leukemia and lymphoma. Establishing a CAR T cell platform to target neoplasms of T-cell origin has been hindered by the shared expression of most targetable antigens on both malignant and normal T lymphocytes, which can promote CAR T cell fratricide. CD5 is one such pan-T cell surface marker present in ~85% of T-cell malignancies. We developed a second-generation CD5-specific CAR with CD28 costimulatory endodomain that produces minimal and transient fratricide when expressed in T cells. We designed this study to evaluate the safety and feasibility of treating patients with r/r T-cell malignancies with these CD5 CAR T cells as a bridge to allogeneic hematopoietic stem cell transplant (HSCT). Secondary objectives of our study included evaluating the antitumor response, in vivo expansion, persistence of CD5 CAR T cells, as well as their impact on normal T-cell numbers and function. Patients and methods: CD5 CAR T cells were generated from autologous PBMCs using gammaretroviral transduction and cryopreserved. We detected no residual malignant cells in the CD5 CAR T cell products by flow cytometry. To date, we have treated a total of 9 patients (8 adults and 1 adolescent; age 16-71 years [median 62 yrs]) with CD5+ r/r T-acute lymphoblastic leukemia (T-ALL; n=4) or T-non-Hodgkin's lymphoma (T-NHL; n=5) on dose levels 1 and 2. All patients were transplant-eligible with an identified allogeneic HSCT donor, yet unable to proceed due to residual disease. All patients had been heavily pretreated, with a median of 5 (range 2 -18) prior lines of therapy. Two patients had previously failed allogeneic HSCT. Patients received cytoreductive chemotherapy with cyclophosphamide and fludarabine followed by a single dose of CD5 CAR T cells. We evaluated adverse events, clinical responses, and in vivo expansion and persistence pre and post-infusion. Results: Three patients received CD5 CAR T cells on dose level 1 (1x107 CAR T cells/m2) and 6 on dose level 2 (5x107 CAR T cells/m2). In all patients treated, CAR T cells reached peak expansion in peripheral blood (PB) 1-4 weeks following infusion, followed by a gradual contraction in most patients (Figure 1). CD5 CAR T cells were present in lymph node and marrow biopsies in patients with T-NHL and T-ALL, respectively, and were also detected in a CSF sample in 1 T-ALL patient. After cytoreduction and CAR T cell infusion, we observed decreased PB CD3+ cell numbers but this ablation was never complete. Cytokine release syndrome (CRS) occurred in 3/9 patients (all at dose level 2). Grade 1 CRS was observed in 2 patients. One patient experienced Grade 2 CRS and Grade 2 neurotoxicity, which resolved after administration of tocilizumab and supportive care, respectively. Two patients had prolonged cytopenias at 6 weeks, 1 of whom had viral reactivation (CMV and BK virus) requiring antiviral therapy. On disease re-evaluation 4-8 weeks post-CD5 CAR T cell infusion, 4 of 9 evaluable patients obtained an objective response (1 of 3 on DL1 and 3 of 6 on DL2). Complete responses (CR) were achieved in 3 patients, one with angioimmunoblastic T cell lymphoma (AITL), one with peripheral T cell lymphoma (PTCL), and one with T-ALL. Two of these patients did not wish or were unable to proceed to planned HSCT and relapsed with their underlying CD5+ malignancy at 6 weeks and 7 months post-infusion. The remaining patient is currently undergoing work-up for HSCT (Figure 2). An additional patient with extensive AITL was classified as a mixed response (Figure 3) due to the appearance of a new PET-avid lesion. This patient received a second infusion of CD5-CAR T cells, proceeded to HSCT, and remains in CR at 125 days post-transplant. Conclusions: These results demonstrate that CD5 CAR T cells are safe and can induce clinical responses in heavily treated patients with r/r CD5+ T-ALL and T-NHL without inducing complete T-cell aplasia. Importantly, elimination of malignant T cells by CD5 CAR T cells may allow previously ineligible patients to proceed to HSCT. Disclosures Rouce: Novartis: Consultancy, Honoraria; Tessa Therapeutics: Research Funding; Kite, a Gilead Company: Consultancy, Honoraria. Grilley:Allovir: Consultancy, Equity Ownership; Marker Therapeutics: Consultancy; Tessa: Consultancy. Heslop:Marker Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Allovir: Equity Ownership; Gilead Biosciences: Membership on an entity's Board of Directors or advisory committees; Kiadis: Membership on an entity's Board of Directors or advisory committees; Tessa Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Cell Medica: Research Funding. Brenner:Allovir: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Marker Therapeutics: Equity Ownership; T Scan: Membership on an entity's Board of Directors or advisory committees; Tessa Therapeutics: Equity Ownership; Memgen: Membership on an entity's Board of Directors or advisory committees; Allogene: Membership on an entity's Board of Directors or advisory committees.

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CD30-Chimeric Antigen Receptor (CAR) T Cells for Therapy of Hodgkin Lymphoma (HL)

Blood ◽

10.1182/blood-2018-99-111202 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 680-680 ◽

Cited By ~ 13

Author(s):

Carlos A. Ramos ◽

Mrinalini Bilgi ◽

Claudia P. Gerken ◽

Olga Dakhova ◽

Zhuyong Mei ◽

...

Keyword(s):

T Cells ◽

Board Of Directors ◽

Chimeric Antigen Receptor ◽

Research Funding ◽

Antigen Receptor ◽

Target Cells ◽

Advisory Committees ◽

Car T Cells ◽

Car T ◽

Equity Ownership

Abstract CD19-specific CAR-T cells are highly successful against B-cell non-Hodgkin lymphomas and acute lymphoblastic leukemia but targets for other lymphoproliferative disorders have been harder to define. Almost all HL and some NHL express the CD30 antigen both at diagnosis and relapse, and monoclonal antibodies (mAb) targeting CD30 (e.g. brentuximab) produce objective antitumor responses. However, mAb have limited bio-distribution and their benefits may be short-lived. We therefore expressed the antigen binding domain of a CD30 mAb as part of a chimeric antigen receptor (CAR) on T cells, coupled to the CD28 and z chain endodomains. We have previously published results of a phase 1 study of activated autologous CD30.CAR-T cells (CD30.CARTs) infused in patients with relapsed/refractory CD30+ HL or NHL without preceding chemotherapy (Ramos et al., J Clin Invest 2017). Of 6 patients with relapsed active HL, 1 entered complete remission (CR) that has lasted more than 3 years, and 3 had transient stable disease. No significant toxicities were observed. In order to boost the in vivo expansion and potentially the efficacy of these CD30.CARTs we are now infusing them after lymphodepleting chemotherapy (RELY-30, NCT02917083). We report here preliminary results of that study, which suggest a substantial improvement in efficacy. We have manufactured CD30.CARTs for 15 patients using retroviral transduction. Culture duration was 15±3 days, with a final transduction efficiency of 97.6%±1.8%. The cell products comprised >98% T cells, with a majority of them being effector T cells (CD45RO+ 95.5%±6.0%). 51Cr-release cytotoxicity assays confirmed that patients' CD30.CARTs lysed a CD30+ tumor line, HDLM-2 (45.9%±15.4% killing at a 20:1 effector:target ratio), with negligible effects on CD30− target cells (<5% killing). During cell manufacture, 1 patient became ineligible due to rapid worsening of his performance status and liver function. Five patients are awaiting treatment on trial. Nine relapsed/refractory HL patients have received CD30.CARTs under the RELY-30 trial. Six of these had relapsed or progressed after treatment with brentuximab. Three patients have been treated on dose level (DL) 1 (2×107 CD30.CAR+ T cells/m2) and 6 patients on DL2 (1×108). All patients received lymphodepleting chemotherapy (cyclophosphamide 500 mg/m2 and fludarabine 30 mg/m2 daily for 3 days) before CART infusion. CART infusions were associated with grade 1 cytokine release syndrome in 4 of the patients, and a transient maculopapular rash in 6 of the patients, starting approximately one week after administration. The molecular signal from CARTs, assessed by Q-PCR in peripheral blood, peaked at 1-2 weeks following infusion, but dropped progressively after 4 weeks and decreased to near the limit of detection level by 6 months post infusion. The signal level was dose dependent, with a peak average of 19,371 copies/mg DNA in patients treated on DL2 versus 7,132 copies/mg for DL1. Compared to patients who received the same CART dose but who were not given lymphodepleting chemotherapy in our previous trial, expansion levels were 45 and 119-fold higher, respectively. Eight patients have been evaluated at 6 weeks after infusion. Six have had a CR lasting from >6 weeks to >6 months, while 2 patients had disease progression. In conclusion, our data indicate that infusion of T cells carrying a CD30.CAR containing a CD28 endodomain after lymphodepleting chemotherapy is safe, with limited toxicities at the dose levels tested. CD30.CAR expansion is improved with inclusion of pre-infusion standard lymphodepleting chemotherapy and appears to be associated with improved efficacy in relapsed patients (6/8 CR versus 1/6 CR, P = 0.03). Disclosures Rooney: Marker: Equity Ownership. Heslop:Marker: Equity Ownership; Cytosen: Membership on an entity's Board of Directors or advisory committees; Tessa Therapeutics: Research Funding; Cell Medica: Research Funding; Gilead Biosciences: Membership on an entity's Board of Directors or advisory committees; Viracyte: Equity Ownership. Brenner:Marker: Equity Ownership.

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Potent Synergy between Combination of Chimeric Antigen Receptor (CAR) Therapy Targeting CD19 in Conjunction with Dendritic Cell (DC)/Tumor Fusion Vaccine in Hematological Malignancies

Blood ◽

10.1182/blood-2019-124944 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 3227-3227

Author(s):

Marzia Capelletti ◽

Jessica Liegel ◽

Maria Themeli ◽

Tuna Mutis ◽

Dina Stroopinsky ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Board Of Directors ◽

Research Funding ◽

Advisory Board ◽

Advisory Committees ◽

Car T Cells ◽

Car T Cell ◽

Car T ◽

Equity Ownership

Introduction: CAR T cells have demonstrated unique potency for tumor cytoreduction and the potential for durable response in patients with advanced hematological malignancies. However, disease relapse remains a significant concern due to the emergence of antigen negative variants, tolerization of CAR T cell populations and lack of T cell persistence. We have developed a personalized cancer vaccine in which patient derived tumor cells are fused with autologous dendritic cells such that a broad array of tumor antigens is expressed in the context of DC mediated co-stimulation. Vaccination of patients with acute leukemia and multiple myeloma has been associated with the durable expansion of tumor specific lymphocytes in the bone marrow and peripheral blood, targeting of residual disease, and durable remission. We postulated that vaccination with DC/tumor fusions would enhance CAR T cell efficacy through the expansion of T cell clonal populations targeting tumor cells via the native TCR and the vaccine mediated enhancement of T cell activation and persistence. In addition, ex vivo engineered CAR T cells provide a substrate of functionally competent T cells with cytoreductive capacity in the setting of advanced disease. In the present study, we examined the potential synergy between CAR T cells targeting CD19 and syngeneic DC/tumor fusions. Methods/Results: CAR T cells and DC/tumor fusions were studied in the context of a murine A20 lymphoma model. CD19 CAR T cells were established through retroviral transduction of a CD19 CAR construct expressing CD28 and 41BBL syngeneic DC/A20 fusions were generated as previously described. Vaccine stimulated T cells were generated by coculturing splenocyte derived T cells with syngeneic DC/A20 fusion cells over a period of three days in a 10:1 ratio in the presence of low dose IL2. While CD19 CAR T cells effectively lysed a subset of A20 cells in a CTL, the addition of vaccine educated T cells increased the percentage of tumor cells undergoing CTL mediated lysis (20% vs 34%). We subsequently examined the interaction of vaccine and CAR T cells ex vivo using the IncuCyte S3 Live-Cell Analysis System which allows for live cell visualization of lysis of A20 cells over time. We studied the impact of combining vaccine educated and CAR T cells as well as an individual T cell population that underwent sequential vaccine mediated stimulation followed by transduction with the CD19 CAR. While vaccine educated and CAR T cells demonstrated potent lysis of A20 cells over time, coculture with either combined vaccine educated and CAR T cells or sequentially vaccine educated and transduced T cells demonstrated the highest levels of cytotoxicity that was maintained over time (1786 and 2338 signal overlap count per image at 23 hours compared to 123 of the control). Enhanced lysis by combined vaccine stimulation and CAR T cells was similarly demonstrated in another tumor cell line, 5TGM1, a multiple myeloma cell line transduced to express CD19. Cytotoxic killing of the 5TGM1-CD19 cells was most pronounced when combining vaccine educated and CAR T cells as compared to CAR T cells alone (33% vs 14%). Consistent with the broad targeting of vaccine educated as compared to the CAR T cell population, wild type 5TGM1 cells were recognized by the DC/tumor fusion stimulated cells in contrast to CAR T cells alone (40% vs. 8%). We subsequently examined the capacity of vaccine educated T cells in conjunction with CAR T cells to target A20 cells in an immunocompetent murine model. Mice were challenged with 1 x 10(6) A20 Mcherry-Luc and lymphoma engraftment was demonstrated at Day 7. Animals were then treated with 3 x 10(6) T cells consisting of CAR T cells, vaccine educated T cells or the combination. Serial bioluminescence imaging demonstrated greatest reduction in tumor burden using combined CAR T and vaccine educated T cells with 4/5 animals without BLI evidence of disease at day 13 after tumor challenge. Conclusions: In in vitro and immunocompetent murine models, we have demonstrated that combined therapy with T cells stimulated by DC/tumor fusions and CAR T cells exhibited potent lysis of murine lymphoma and myeloma cells as compared to the efficacy of CAR T cells or vaccine educated T cells alone. These findings suggest potent synergy between these modalities that may overcome recognized pathways of resistance including the broadening of the tumor specific response and vaccine mediated activation of CAR T cell populations. Disclosures Themeli: Covagen: Consultancy. Mutis:Janssen Research and Development: Research Funding; Celgene: Research Funding; Onkimmune: Research Funding; Genmab: Research Funding. Munshi:Adaptive: Consultancy; Amgen: Consultancy; Oncopep: Consultancy; Janssen: Consultancy; Celgene: Consultancy; Takeda: Consultancy; Abbvie: Consultancy. Kufe:Genus Oncology: Equity Ownership; Reata Pharmaceuticals: Consultancy, Equity Ownership, Honoraria; Nanogen Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Hillstream BioPharma: Equity Ownership; Victa BioTherapeutics: Consultancy, Equity Ownership, Honoraria, Membership on an entity's Board of Directors or advisory committees; Canbas: Consultancy, Honoraria. Rosenblatt:BMS: Research Funding; Amgen: Other: Advisory Board; Merck: Other: Advisory Board; BMS: Other: Advisory Board ; Parexel: Consultancy; Imaging Endpoint: Consultancy; Partner Tx: Other: Advisory Board; Dava Oncology: Other: Education; Celgene: Research Funding. Sadelain:Fate Therapeutics: Consultancy, Patents & Royalties; Memorial Sloan Kettering Cancer Center: Employment; Juno Therapeutics: Consultancy, Patents & Royalties, Research Funding. Avigan:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Research Funding; Juno: Membership on an entity's Board of Directors or advisory committees; Partners Tx: Membership on an entity's Board of Directors or advisory committees; Partner Tx: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; Parexel: Consultancy; Takeda: Consultancy.

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PD-1 Inhibitor Combinations As Salvage Therapy for Relapsed/Refractory Multiple Myeloma (MM) Patients Progressing after Bcma-Directed CAR T Cells

Blood ◽

10.1182/blood-2018-99-119514 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1973-1973 ◽

Cited By ~ 8

Author(s):

Luca Bernabei ◽

Alfred L. Garfall ◽

J. Joseph Melenhorst ◽

Simon F Lacey ◽

Edward A. Stadtmauer ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Board Of Directors ◽

Research Funding ◽

Advisory Committees ◽

Car T Cells ◽

Car T Cell ◽

Hla Dr ◽

Car T ◽

Equity Ownership

Abstract Background: Autologous T cells expressing a chimeric antigen receptor (CAR) specific for B-cell maturation antigen (CART-BCMA cells) show activity in refractory MM, but relapses remain common. Anti-PD-1 antibodies (Abs) augment CAR T cell activity pre-clinically, and induced CAR T cell re-expansion and responses in DLBCL patients progressing after CD19-specific CAR T cells (Chong et al, Blood 2017). The IMiDs lenalidomide (len) and pomalidomide (pom) may enhance efficacy, but also toxicity, of both CAR T cells and PD-1 inhibitors in MM. Elotuzumab (elo) has clinical anti-MM activity in combination with IMiDs and dexamethasone (dex), and synergizes with anti-PD-1 Ab in pre-clinical models. Methods: We previously described outcomes of 25 subjects enrolled on our phase 1 study of CART-BCMA cells in relapsed/refractory MM (Cohen et al, ASH 2017, #505). We identified and retrospectively reviewed 5 subjects who progressed after CART-BCMA and received a PD-1 inhibitor (pembrolizumab (pembro)) combination as their next therapy. Responses were assessed by IMWG criteria. CART-BCMA levels were assessed by flow cytometry and qPCR pre-treatment, 2-4 weeks after first pembro dose, then q4 weeks until progression. Pembro dosing was 200mg every 3 weeks; dex dosing was 20-40mg/week. Results: Characteristics of the 5 subjects are in the Table. Median prior lines was 9; all had high-risk cytogenetics. All were refractory to pom, 2 to pembro/pom/dex, and 1 to elo. Best response to CART-BCMA was PR in 2, MR in 2, and PD in 1. Median time from CART-BCMA to pembro-based therapy was 117 days. All patients still had CART-BCMA cells detectable by qPCR, with 2 (pts. 07 and 21) still detectable by flow, at initiation of salvage therapy. The first pt. (02) received pembro/pom/dex and had MR but progressed at 2 months, with no detectable CART-BCMA re-expansion. The second pt. (07) had rapidly-progressing kappa light chain MM 2 months post-CART-BCMA and had previously progressed on pembro/pom/dex. He started elo/pembro/pom/dex and had MR at day 12 (free kappa 1446 to 937 mg/L), associated with robust expansion of CART-BCMA cells (875.64 to 20505.07 copies/µg DNA by qPCR; 0.7% to 6.4% of peripheral CD3+ cells by flow). Re-expanded CART-BCMA cells were predominantly CD8+ and highly activated (89% HLA-DR+, up from 18% pre-therapy). This response was short-lived, however, with progression 1 week later, and return of CART-BCMA levels to baseline at week 5. Three subsequent subjects then received elo/pembro/dex with either len or pom; with 2 MR and 1 SD, and PFS of 3 to 4 months. None had re-expansion of CART-BCMA cells. Non-specific immune modulation was observed and included altered CD4:CD8 T cell ratio (n=5), increased NK cell/decreased T cell frequency (n=4), and HLA-DR upregulation on CAR-negative T cells (n=2). More detailed phenotyping of CART and other immune cells, including PD-1 expression, is ongoing. With regard to toxicity, pt. 02 had self-limiting low-grade fevers and myalgias 4 weeks after pembro/pom/dex, associated with mild elevation in ferritin/CRP, suggestive of mild CRS. No other CRS was noted, including pt. 07 despite CART-BCMA re-expansion. One patient (17) developed recurrent expressive aphasia starting 2 months after elo/pembro/pom/dex, without signs of CRS and no observed expansion of CART-BCMA cells in blood or CSF. This resolved with stopping therapy and brief steroid taper. Conclusions: This study demonstrates that a PD1-inhibitor combination can induce CAR T cell re-expansion and anti-MM response in a MM patient progressing after CART-BCMA therapy. Since this patient previously progressed on pembro/pom/dex, the observed clinical activity was likely related to the CAR T cells, with elotuzumab also possibly contributing. However, this effect was very transient; re-expansion occurred infrequently (1/5 patients); and neurotoxicity was observed (though its relationship to the CAR T cells is unclear). This makes it difficult to endorse this specific salvage regimen. Nonetheless, this proof-of-principle observation suggests that a subset of patients may respond to checkpoint blockade or other immune-modulating approaches following BCMA CAR T cell therapy, meriting further study. Table. Table. Disclosures Garfall: Kite Pharma: Consultancy; Novartis: Research Funding; Amgen: Research Funding; Bioinvent: Research Funding. Melenhorst:novartis: Patents & Royalties, Research Funding; Incyte: Research Funding; Shanghai UNICAR Therapy, Inc: Consultancy; Casi Pharmaceuticals: Consultancy; Parker Institute for Cancer Immunotherapy: Research Funding. Lacey:Parker Foundation: Research Funding; Tmunity: Research Funding; Novartis Pharmaceuticals Corporation: Patents & Royalties; Novartis Pharmaceuticals Corporation: Research Funding. Stadtmauer:Janssen: Consultancy; AbbVie, Inc: Research Funding; Amgen: Consultancy; Takeda: Consultancy; Celgene: Consultancy. Vogl:Karyopharm Therapeutics: Consultancy. Plesa:Novartis: Research Funding. Young:Novartis: Patents & Royalties, Research Funding. Levine:Novartis: Consultancy, Patents & Royalties, Research Funding; Tmunity Therapeutics: Equity Ownership, Research Funding; Incysus: Consultancy; Cure Genetics: Consultancy; CRC Oncology: Consultancy; Brammer Bio: Consultancy. June:Immune Design: Membership on an entity's Board of Directors or advisory committees; Immune Design: Membership on an entity's Board of Directors or advisory committees; Tmunity Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Celldex: Consultancy, Membership on an entity's Board of Directors or advisory committees; Tmunity Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Novartis Pharmaceutical Corporation: Patents & Royalties, Research Funding; Novartis Pharmaceutical Corporation: Patents & Royalties, Research Funding. Milone:Novartis: Patents & Royalties. Cohen:Bristol Meyers Squibb: Consultancy, Research Funding; Celgene: Consultancy; Novartis: Research Funding; Poseida Therapeutics, Inc.: Research Funding; Kite Pharma: Consultancy; GlaxoSmithKline: Consultancy, Research Funding; Seattle Genetics: Consultancy; Janssen: Consultancy; Oncopeptides: Consultancy.

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

Blood ◽

10.1182/blood-2019-129640 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 776-776

Author(s):

Claire Roddie ◽

Maeve A O'Reilly ◽

Maria A V Marzolini ◽

Leigh Wood ◽

Juliana Dias Alves Pinto ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Board Of Directors ◽

Research Funding ◽

Advisory Committees ◽

Car T Cells ◽

Car T Cell ◽

Car T ◽

Peak Car ◽

Matched Donor

Introduction: 2nd generation CD19 CAR T cells show unprecedented efficacy in B-ALL, but several challenges remain: (1) scaling manufacture to meet patient need and (2) feasibility of generating products from lymphopenic patients post allogeneic stem cell transplant (allo-SCT). To overcome these issues we propose: (1) use of the CliniMACS Prodigy (Miltenyi Biotec), a semi-automated cGMP platform that simplifies CAR T cell manufacture and (2) the use of matched donor T cells to overcome the challenge posed by patient lymphopenia, albeit this may come with a heightened risk of graft versus host disease (GvHD). CARD (NCT02893189) is a Phase I study of matched donor derived CD19 CAR T cells generated on the CliniMACS Prodigy in 14 adult patients with relapsed/refractory (r/r) B ALL following allo-SCT. We additionally explore the requirement for lymphodepletion (LD) in the allogeneic CAR T cell setting and report on the incidence of GvHD with this therapy. Methods: Manufacturing: CARD utilises non-mobilised matched donor leucapheresate to manufacture 2nd generation CD19CAR T cells using a closed CliniMACS® Prodigy/ TransACTTM process. Study design: Eligible subjects are aged 16-70y with r/r B ALL following allo SCT. Study endpoints include feasibility of CD19CAR T cell manufacture from allo-SCT donors on the CliniMACS Prodigy and assessments of engraftment and safety including GvHD. To assess the requirement for LD prior to CD19CAR T cells in lymphopenic post-allo-SCT patients, the study is split into Cohort 1 (no LD) and Cohort 2 (fludarabine (30 mg/m2 x3) and cyclophosphamide (300mg/m2 x3)). To mitigate for the potential GvHD risk, cell dosing on study mirrors conventional donor lymphocyte infusion (DLI) schedules and is based on total CD3+ (not CAR T) cell numbers: Dose 1=1x106/kg CD3+ T cells; Dose 2= 3x106/kg CD3+ T cells; Dose 3= 1x107/kg CD3+ T cells. Results: As of 26 July 2019, 17 matched allo SCT donors were leukapheresed and 16 products were successfully manufactured and QP released. Patient demographics are as follows: (1) median patient age was 43y (range 19-64y); (2) 4/17 had prior blinatumomab and 5/17 prior inotuzumab ozogamicin; (3) 7/17 had myeloablative allo SCT and 10/17 reduced intensity allo SCT of which 6/17 were sibling donors and 12/17 were matched unrelated donors. No patients with haploidentical transplant were enrolled. To date, 12/16 patients have received at least 1 dose of CD19CAR T cells: 7/16 on Cohort 1 and 5/16 on Cohort 2 (2/16 are pending infusion on Cohort 2 and 2/16 died of fungal infection prior to infusion). Median follow-up for all 12 patients is 22.9 months (IQR 2.9-25.9; range 0.7 - 25.9). At the time of CAR T cell infusion, 7/12 patients were in morphological relapse with >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.

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