ACTR087, Autologous T Lymphocytes Expressing Antibody Coupled T-Cell Receptors (ACTR), Induces Complete Responses in Patients with Relapsed or Refractory CD20-Positive B-Cell Lymphoma, in Combination with Rituximab

Abstract Background: Autologous T cells engineered to express the universal ACTR chimeric receptor kill tumors through interactions with tumor-targeting antibodies [Kudo, Cancer Res. 2014]. Preclinical findings with ACTR+ T cells, which bind immunoglobulin Fc via CD16V158 and signal via CD3ζ and 4-1BB (ACTR087), demonstrate markedly enhanced target- and antibody-specific tumor cell cytotoxicity, as evidenced by CD20+ B cell lymphoma killing in combination with rituximab, compared with rituximab alone. Preclinical data also demonstrate rituximab dose-dependent effects in combination with ACTR087, suggesting that the therapeutic index of ACTR087 in combination with rituximab may be affected by rituximab dose or schedule and present an advantage over chimeric antigen receptor (CAR) T cell therapies [Huet H, Blood 2016]. Study UT-201501 (ATTCK-20-2) is the first clinical trial of ACTR087 in combination with rituximab in patients with relapsed or refractory CD20+ B cell lymphoma previously treated with rituximab (NCT02776813). We report data from the 7 patients treated with ACTR087 in the first dose level of the ATTCK-20-2 study. Methods: This is a multicenter Phase 1 dose escalation study. The primary objective is to evaluate the safety of the combination of ACTR087 and rituximab, and the key secondary objective is to evaluate antitumor efficacy. Exploratory objectives include measurement of ACTR T cell persistence, cytokines, and rituximab pharmacokinetics. Eligible patients must have histologically confirmed relapsed/refractory aggressive CD20+ B cell lymphoma of DLBCL, MCL, PBMCL, Gr3b FL, or transformed FL subtype and have received prior anti-CD20 mAb in combination with anthracycline-containing chemotherapy. In the first dose level, patients received lymphodepleting chemotherapy (cyclophosphamide 500 mg/m2 and fludarabine 30 mg/m2) for 3 days, followed by rituximab (375 mg/m2) and ACTR087 (0.5x106 ACTR+ T cells/kg). Up to 7 additional doses of rituximab are then administered, one dose every 3 weeks in the absence of disease progression. Results: Seven patients received ACTR087 in combination with rituximab at the first dose level. Median age was 64 years (range: 36-71), 57.1% were male, all had ECOG PS 1, 86% were treated with ≥ 3 lines of prior therapy, and 86% were refractory to the immediate prior therapy. ACTR087 was successfully manufactured for all subjects. ACTR+ T cells were detectable in the peripheral blood and demonstrated expansion post-infusion. One patient had a dose-limiting toxicity of grade 4 thrombocytopenia for > 14 days that later resolved. At the first dose level, there were no SAEs or deaths related to ACTR087 and no AEs of special interest, including cytokine-release syndrome, neurotoxicity, or autoimmune events. Cytopenias were the most common ≥ grade 3 AEs (neutropenia n=7, leukopenia n=5). Rituximab pharmacokinetics were not affected by ACTR087 administration. Independently-confirmed objective responses were observed in patients evaluable for response (n=6), including 2 ongoing complete responses (CR) and 1 partial response (PR). One of the CRs continues 6+ months after a single dose of ACTR087. Conclusions:In the first dose level studied in patients with relapsed/refractory aggressive CD20+ B cell lymphoma, ACTR087 in combination with rituximab induced complete responses with no serious AEs, AEs leading to treatment discontinuation, cytokine-release syndrome, or neurotoxicity. ACTR+ T cells were detectable in all patients and ACTR+ T cells persisted in the presence of continued rituximab administration. These results support the continued dose escalation of ACTR087 in combination with rituximab; dose level 2 enrollment is ongoing and updated data, including correlative biomarkers, will be presented. Disclosures Jaglowski: Novartis Pharmaceuticals Corporation: Consultancy, Research Funding; Kite Pharma: Consultancy, Research Funding; Unum Therapeutics: Research Funding; Pharmacyclics Inc: Research Funding. McKinney: Kite Pharma: Other: advisory comittee. Vasconcelles: Unum Therapeutics Inc: Employment. Huet: Unum Therapeutics Inc: Employment. Ettenberg: Unum Therapeutics Inc.: Employment. Ranger: Unum Therapeutics Inc: Employment. Abramson: Seattle Genetics: Consultancy; Genentech: Consultancy; Gilead: Consultancy; Kite Pharma: Consultancy; Abbvie: Consultancy; Celgene: Consultancy; LAM Therapeutics: Research Funding; Novartis: Consultancy.

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Preliminary Clinical Results of a Phase 1 Study Evaluating the Safety and Anti-Tumor Activity of ACTR707 in Combination with Rituximab in Subjects with Relapsed or Refractory CD20+ B-Cell Lymphoma

Blood ◽

10.1182/blood-2018-99-111622 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 2966-2966 ◽

Cited By ~ 1

Author(s):

Ian W. Flinn ◽

Jonathon B. Cohen ◽

Luke P. Akard ◽

Samantha Jaglowski ◽

Michael Vasconcelles ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Board Of Directors ◽

Dose Level ◽

Dose Escalation ◽

Research Funding ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Advisory Committees

Abstract Background: Recent regulatory approvals of two CD19-targeted chimeric antigen receptor (CAR)-expressing autologous T lymphocyte therapies provide compelling evidence of the clinical potential of re-engineering T cells to specifically attack tumor cells, but the broader applicability of these therapies is constrained by safety considerations and target specificity. A universal approach to T cell therapy that enables flexibility in tumor target selection has been demonstrated by engineering autologous T cells to express an antibody-coupled T cell receptor (ACTR) composed of the ectodomain of the CD16 Fc receptor fused to costimulatory and CD3ζ signaling domains. Thus, the ACTR platform couples T cell anti-tumor effector functions, including cytotoxicity, cytokine production, and T cell proliferation, to target-specific therapeutic antibodies. Here we present the preliminary clinical findings of the ongoing, multicenter Phase 1 study, ATTCK-20-03 (NCT03189836), of ACTR707, a CD28-containing ACTR chimeric receptor, in combination with rituximab in subjects with relapsed or refractory CD20+ B cell lymphoma. Methods: The primary objectives of this first-in-human, dose escalation study are to evaluate the safety of the combination of ACTR707 and rituximab and to determine a maximum tolerated dose (MTD) and a proposed recommended phase 2 dose (RP2D). Other objectives include evaluation of antitumor activity, and assessment of ACTR T cell persistence, cytokine levels, and rituximab pharmacokinetics. Eligible subjects must have histologically confirmed relapsed or refractory CD20+ non-Hodgkin lymphoma and have received prior anti-CD20 mAb in combination with chemotherapy. Subjects received lymphodepleting chemotherapy (cyclophosphamide 400 mg/m2 and fludarabine 30 mg/m2) for 3 days, followed by rituximab (375 mg/m2) and ACTR707. Additional doses of rituximab were administered, one dose every 3 weeks in the absence of disease progression. The study is separated into 2 sequential phases, a dose escalation and a safety expansion phase. During the dose escalation phase, ACTR707 is being tested at increasing doses in combination with rituximab. Results: Six subjects were enrolled and received ACTR707 at the first dose level in combination with rituximab: 5 diagnosed with diffuse large B cell lymphoma (83%) and one with follicular lymphoma, Grade 3b (17%). Median age was 61 years (range: 57-76), 83% were male, 50% were treated with ≥3 lines of prior therapy, and 67% had no response to or relapse within 6 months from immediate prior therapy. ACTR707 was successfully manufactured for all subjects and demonstrated post-infusion expansion in the peripheral blood. ACTR+ T cells were detectable at Day 28 post-infusion for all subjects tested. No dose-limiting toxicities (DLTs) were observed at the first dose level in 4 DLT-evaluable subjects (2 subjects experienced disease progression during the DLT evaluation period). There were no cytokine release syndrome (CRS) or autoimmune adverse events (AEs), serious or severe (≥Gr3) neurotoxicity AEs, or deaths on treatment. AEs (all grades) reported in >1 subject included neutropenia (n=3), anemia, decreased appetite, febrile neutropenia, and thrombocytopenia (each in 2 subjects); the 2 events of febrile neutropenia were considered serious. Investigator-reported complete responses were observed in 3 of 6 subjects. These complete responses (duration of response range: 47+ to 81+ days) are ongoing as of the data cut-off. Enrollment into the second dose level is ongoing. Conclusions: ACTR707 in combination with rituximab induced complete responses in 3 of 6 subjects with relapsed or refractory aggressive CD20+ B cell lymphoma treated at the first dose level with ACTR707 in combination with rituximab, with no CRS, serious or severe (≥Gr3) neurotoxicity, or AEs leading to treatment discontinuation. ACTR+ T cells were detectable in all subjects and persisted. These results support the continued dose escalation of ACTR707 in combination with rituximab. Updated data, inclusive of preliminary dose level 2 and correlative biomarkers, will be presented. Disclosures Flinn: Verastem: Consultancy, Research Funding; Janssen: Research Funding; Pfizer: Research Funding; Kite: Research Funding; Forty Seven: Research Funding; BeiGene: Research Funding; ArQule: Research Funding; Takeda: Research Funding; TG Therapeutics: Research Funding; Incyte: Research Funding; Forma: Research Funding; Verastem: Research Funding; Novartis: Research Funding; Agios: Research Funding; Seattle Genetics: Research Funding; Trillium: Research Funding; Merck: Research Funding; Calithera: Research Funding; Constellation: Research Funding; Gilead: Research Funding; Genentech: Research Funding; Infinity: Research Funding; Portola: Research Funding; Pharmacyclics: Research Funding; Curis: Research Funding; Celgene: Research Funding. Cohen:BioInvent: Consultancy; Bristol-Myers Squibb: Research Funding; Celgene: 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, Research Funding; Janssen: Research Funding; Infinity Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Research Funding. Akard:Gilead: Speakers Bureau; Celgene: Speakers Bureau; Takeda: Speakers Bureau; Novartis: Speakers Bureau; Bristol-Myers Squibb: Speakers Bureau. Jaglowski:Novartis Pharmaceuticals Corporation: Consultancy, Research Funding; Kite Pharma: Consultancy, Research Funding; Juno: Consultancy. Vasconcelles:Unum Therapeutics: Employment. Ranger:Unum Therapeutics: Employment. Harris:Unum Therapeutics: Employment. Payumo:Unum Therapeutics: Employment. Motz:Unum Therapeutics: Employment. Bachanova:Gamida Cell: Research Funding; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; GT Biopharma: Research Funding.

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Phase 1 Study of Bortezomib and Romidepsin in Patients with Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma, Indolent B-Cell Lymphoma, Peripheral T-Cell Lymphoma, or Cutaneous T-Cell Lymphoma: Updated Results

Blood ◽

10.1182/blood.v124.21.3050.3050 ◽

2014 ◽

Vol 124 (21) ◽

pp. 3050-3050 ◽

Cited By ~ 3

Author(s):

Beata Holkova ◽

Maciej Kmieciak ◽

Prithviraj Bose ◽

Shuo Ma ◽

Amy Kimball ◽

...

Keyword(s):

T Cell ◽

B Cell ◽

Dose Level ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Lymphocytic Leukemia ◽

T Cell Lymphoma ◽

Cytokine Release ◽

Cytokine Release Syndrome ◽

Grade 3

Abstract The combination of proteasome and histone deacetylase (HDAC) inhibitors has shown synergistic interactions in pre-clinical studies involving diverse hematologic malignancies. We have previously reported that the combination of the proteasome inhibitor bortezomib and the HDAC inhibitor romidepsin, administered at extremely low concentrations (eg, ~3-5 nM), results in a striking increase in apoptosis in primary chronic lymphocytic leukemia (CLL) cells, including cells obtained from patients with CLL refractory to standard treatments (Dai Y et al. Clin Cancer Res. 2008). Romidepsin is an approved agent for both cutaneous T-cell lymphoma (CTCL) and peripheral T-cell lymphoma (PTCL). Based on these findings, a phase 1 trial was initiated, using a 3+3 design, with the primary objective of determining the maximum tolerated dose (MTD) for the combination of bortezomib and romidepsin in patients with relapsed or refractory CLL/small lymphocytic lymphoma (SLL), indolent B-cell lymphoma, PTCL, or CTCL. Eighteen patients (13 with CLL/SLL, 1 with CTCL, 2 with indolent B-cell lymphoma, and 2 with PTCL; 15 male, 3 female) were enrolled and treated. The median age was 56.5 years (range 31-76); ECOG performance scores ranged from 0 to 1; and the median number of prior therapies was 3 (range 1-6). Bortezomib was administered as an intravenous bolus followed by a 4-hour intravenous infusion of romidepsin on days 1, 8, and 15 of 4-week cycles. The dose levels were: dose level 1 = bortezomib 1.3 mg/m2, romidepsin 8 mg/m2 (n = 3); dose level 2A = bortezomib 1.3 mg/m2, romidepsin 10 mg/m2 (n = 9); and dose level 2B = bortezomib 1.6 mg/m2, romidepsin 8 mg/m2 (n = 6). Adverse events (AEs) and dose-limiting toxicities (DLTs) were determined using NCI-CTCAE version 4 and protocol guidelines. DLTs were determined in cycle 1 only. There was 1 DLT at dose level 2A (grade 3 fatigue), 2 DLTs at dose level 2B (grade 3 chills [associated with grade 2 cytokine release syndrome] and grade 3 vomiting), and no DLTs at dose level 1 (Table 1). Accrual to dose levels 2A and 2B took place using an alternating enrollment schema. Dose level 2A was identified as the MTD. Non-DLT grade 3 AEs for all treated patients possibly, probably, or definitely related to study treatment included anemia (6%), cytokine release syndrome (6%), fatigue (11%), leukopenia (6%), lymphopenia (6%), nausea (6%) neutropenia (11%), soft tissue infection (6%), vomiting (11%), and grade 4 neutropenia (17%). Common grade 2 AEs possibly, probably, or definitely related to study treatment included fatigue (44%), leukopenia (22%), nausea (44%), neutropenia (39%), and thrombocytopenia (39%). All 18 patients treated in this study were evaluable for response. One partial response has been observed to date in a patient with CLL who was ZAP70 positive and had received 4 lines of prior chemotherapy. After 4 cycles of romidepsin and bortezomib, this patient proceeded to a stem cell transplant from an unrelated donor and has remained in complete remission since 2012. Nine patients had a best response of stable disease (CLL/SLL = 6; CTCL = 1; indolent B-cell lymphoma = 2 [1 patient still on treatment]) and 8 had progressive disease. Correlative studies examining pre- and post-treatment expression of NF-кB, XIAP, Bcl-xL, and Bim were performed for 3 patients and yielded variable results. Although the small sample size did not permit correlations to be made between protein expression of these markers and treatment outcome, the ability to obtain these data supports the feasibility of the correlative methodology. The MTD was reached at dose level 2A (Table 1). The study is closed to accrual and one patient remains on treatment at dose level 2A. The safety profile is consistent with those reported for bortezomib and romidepsin, with reversible grade 2 to 4 AEs. The regimen appears to have modest activity in heavily pretreated patients with relapsed/refractory CLL/SLL, indolent B-cell lymphoma, or CTCL. Table 1. Dose Level Enrollment and DLTs Dose Level Bortezomib (mg/m2) Romidepsin (mg/m2) Patients treated/# DLTs DLT 1 1.3 8 3/0 2A* 1.3 10 9/1 Grade 3 fatigue 2B** 1.6 8 6/2 Grade 3 chills (associated with cytokine release syndrome) Grade 3 vomiting *MTD **Exceeded MTD Disclosures Holkova: Seattle Genetics, Inc.: Research Funding. Bose:Celgene: Membership on an entity's Board of Directors or advisory committees. Roberts:Selexys: Research Funding.

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Analysis of CAR-T and Immune Cells within the Tumor Micro-Environment of Diffuse Large B-Cell Lymphoma Post CAR-T Treatment By Multiplex Immunofluorescence

Blood ◽

10.1182/blood-2018-99-113644 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 678-678 ◽

Cited By ~ 3

Author(s):

Pei-Hsuan Chen ◽

Mikel Lipschitz ◽

Kyle Wright ◽

Philippe Armand ◽

Caron A. Jacobson ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Cd8 T Cells ◽

Research Funding ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Car T Cells ◽

Car T Cell ◽

Car T

Abstract BACKGROUND: Axicabtagene ciloleucel is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy that shows efficacy in patients with refractory diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma and transformed follicular lymphoma after failure of conventional therapy. However, the exact mechanism of anti-tumor immunity is poorly understood, in part due to the dearth of data on the events in the tumor micro-environment (TME) that occur upon exposure to CAR-T cells. We sought to quantify and characterize both CAR-T cells and non-CAR T cells within the TME of DLBCL using tissue biopsy samples collected in the ZUMA-1 multicenter trial of CAR-T cell therapy for patients with refractory DLBCL. METHODS: Tumor samples obtained from patients 5-30 days (median 10 days) after CAR-T infusion ("CAR-treated", n=14) and randomly-selected untreated ("untreated ", n=15) archival DLBCL tissue samples were analyzed by multiplex immunofluorescence using formalin-fixed, paraffin embedded tissue sections, with successive labeling by the primary antibodies KIP-1 and/or KIP-3 (recognizing separate CD19 CAR epitopes), PAX5, PD-1, CD4, and CD8, followed by secondary amplification and tyramide-conjugated fluorophores. For each case, at least 3 representative 20x fields of view were selected and imaged using a multispectral imaging platform. Two specific image analysis algorithms were designed to accurately identify CD4 and CD8 T cells and PAX5+ DLBCL cells simultaneously, then to threshold PD-1 and KIP-1/-3 by relative fluorescent units (RFU) in each phenotype. RESULTS: We identified CAR T-cells within the fixed biopsy samples of CAR-treated DLBCLs by immunostaining with CAR T-cell specific antibody KIP-1; at the timepoints analyzed, CAR T-cells comprised only a small minority of total T- cells (<2%) and included CD4+ and CD8+ T-cells. Immunostaining with a second antibody, KIP-3, validated the presence of CAR T-cells in these cases and confirmed the KIP-1 results. Expression of the T cell activation marker PD-1 was detected among majority of KIP-1+ cells. Further analysis that included KIP1-negative cells revealed that the percentage of CD8+ cells co-expressing PD-1 across all CD8+ cells was higher in the CAR-treated DLBCLs compared to the untreated DLBCLs (mean 50.1% vs 17.5%, p<0.0001 with unpaired t test ), indicating CD8 T cell activation within the tumor environment. In contrast, PD-1 positivity across CD4+ T cells were equivalent between the two groups (mean 21.8% vs 21.6%, ns with unpaired t test). The percentages of total, CD4+, and CD8+ T-cell populations in the TME were similar between the CAR-treated DLBCL and untreated biopsies. CONCLUSIONS: CD4+ and CD8+ CAR-T cells can be detected in CAR-treated DLBCL patient tissue biopsies by multiplex immunofluorescence. At the time points analyzed to date, CAR-T cells comprise only a small percentage of all T-cells (<2%) within the TME. However, the presence of gene marked T cells with downregulated CAR protein expression is also possible. The activation marker PD-1 is preferentially expressed by KIP-1-negative CD8+ T cells compared to CD4+ T cells in CAR-T treated DLBCLs relative to untreated DLBCLs. These data implicate preferential activation of CD8+ non-CAR "by-stander" T-cells in the post CAR-T TME, and the possible benefit of combining PD-1 blockade with CAR-T therapy in DLBCL. *PH.C and M.L share equal contribution. Disclosures Armand: Otsuka: Research Funding; Affimed: Consultancy, Research Funding; Pfizer: Consultancy; Infinity: Consultancy; Adaptive: Research Funding; Merck: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Roche: Research Funding; Tensha: Research Funding. Roberts:KITE: Employment. Rossi:KITE: Employment. Bot:KITE: Employment. Go:KITE: Employment. Rodig:Merck: Research Funding; Bristol Myers Squibb: Research Funding; Affimed: Research Funding; KITE: Research Funding.

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Somatic PRAME Deletions Are Associated with Decreased Immunogenicity, Apoptosis Resistance and Poor Outcomes in Diffuse Large B-Cell Lymphoma

Blood ◽

10.1182/blood-2018-99-113516 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 667-667

Author(s):

Katsuyoshi Takata ◽

Daisuke Ennishi ◽

Ali Bashashati ◽

Saeed Saberi ◽

Elena Viganò ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Research Funding ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Wild Type ◽

Memory T Cell ◽

Large B Cell Lymphoma ◽

Large B Cell

Abstract Background: The current standard of care in diffuse large B-cell lymphoma (DLBCL) consists of chemotherapy and therapeutic monoclonal antibodies that have significantly improved patient outcomes over the past 15 years. However, a large proportion of patients suffer from refractory or relapsed disease. Therefore, the development of new therapeutic strategies for this subgroup of patients, who are threatened by a high chance of disease-related death, represents an important unmet clinical need. Methods: We enrolled into our study 347 de novo DLBCL patients uniformly treated with R-CHOP from the BC Cancer population-based cohort between September 2000 and January 2012. RNAseq and high-resolution copy number analysis were performed and correlated with clinical outcome data and tumor microenvironment composition. We also performed functional studies to investigate PRAME-mediated memory T-cell responses and gene expression changes. Results: We discovered novel, highly focal deletions of 22q11.22, including the PRAME gene in 13% (44/338) of the cases. The deletions cluster in a narrow chromosomal region that includes a very small number of genes (VpreB1, ZNF280A/B, PRAME, GGTLC2, miR-650). Of clinical importance, 22q11.22 deletions were found significantly more frequently in germinal centre B-cell-like (GCB) type DLBCL (17% (31/180) vs. activated B-cell-like (ABC) type: 8% (8/98), P < 0.01), and were also significantly associated with worse outcome, which was specifically observed in GCB-DLBCL (5-year disease specific survival, non-PRAME-deleted: 84.5% vs. PRAME-deleted: 67.2%, P = 0.026). Homozygous deletions were more strongly associated with poor outcome than heterozygous deletions. Interestingly, 90% of PRAME-deleted cases were Ig-lambda restricted (P < 0.001). PRAME is a prominent member of the cancer testis antigen (CTA) family of proteins that are expressed in various types of cancers, but not in normal tissues, including normal mature B-cells, apart from male germinal cells. Due to the cancer-specific expression of CTAs, these molecules are considered promising targets for cancer immunotherapy using cytotoxic T-cells and tumor vaccination approaches. To determine the association with tumor microenvironment composition, we analyzed CD4/CD8 flow cytometry data from DLBCL patient samples. The numbers of CD4 and CD8-positive T cells were significantly lower in PRAME-deleted cases compared to wild type (CD4: P < 0.001, CD8: P = 0.013). Notably, RNAseq analysis revealed that the HLA-A*0201 genotype was seen significantly more often in PRAME deleted cases (PRAME wt: 2.5% vs. PRAME deleted: 10.8%, P = 0.005). In order to functionally characterize its interaction with the immune microenvironment, we utilized enzyme-linked immunoSpot (ELISPOT) assays to investigate memory T-cell reactions of patient-derived T cells to PRAME antigens using patient-derived peripheral blood mononuclear cells (PBMC) and measured IFN-g production (7 control healthy donors, 4 PRAME-deleted and 4-wild type patients). While T cells from PRAME-replete patients had no reaction to PRAME antigens, PRAME-deleted patient-derived T-cells had significant reactions to 4 independent PRAME peptides. These data suggest that PRAME-deleted tumor cells can escape from cytotoxic T-cell attack to gain growth advantage. Next, we performed PRAME knock-out (KO) experiments using CRISPR/Cas9 genome editing to clarify the cell autonomous effects of PRAME deletions. Using 2 different cell lines (Karpas422 and SUDHL-4), we found TNFSF10 (TRAIL) expression was significantly down-regulated in homozygous PRAME-KO cell lines compared to wild type. The soluble form of TRAIL (sTRAIL) was also reduced, as measured with enzyme-linked immunosorbent assays. These results suggest that PRAME downregulated cells may contribute to cell survival via TRAIL and sTRAIL reduction. Conclusion: We identified recurrent PRAME deletions and characterized their clinical and functional role in DLBCL. Our findings contribute to the understanding of cell-autonomous and extrinsic roles of PRAME deletions in lymphomagenesis and may lead to the discovery of new therapeutic avenues to simultaneously treat the tumor and the host. Disclosures Gascoyne: NanoString: Patents & Royalties: Named Inventor on a patent licensed to NanoString Technologies. Scott:Janssen: Research Funding; Roche: Research Funding; NanoString: Patents & Royalties: Named Inventor on a patent licensed to NanoString Technologies, Research Funding; Celgene: Consultancy, Honoraria. Steidl:Tioma: Research Funding; Seattle Genetics: Consultancy; Roche: Consultancy; Bristol-Myers Squibb: Research Funding; Juno Therapeutics: Consultancy; Nanostring: Patents & Royalties: patent holding.

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ZUMA-11: A Phase 1/2 Multicenter Study of Axicabtagene Ciloleucel (Axi-Cel) + Utomilumab Patients with Refractory Large B Cell Lymphoma

Blood ◽

10.1182/blood-2019-123772 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 4084-4084 ◽

Cited By ~ 1

Author(s):

Ran Reshef ◽

David B. Miklos ◽

John M. Timmerman ◽

Caron A. Jacobson ◽

Nabila N. Bennani ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Research Funding ◽

Cell Lymphoma ◽

Phase 1 ◽

B Cell Lymphoma ◽

Phase 2 ◽

Car T Cells ◽

Car T

Background: Relapsed/refractory (R/R) large B cell lymphoma (LBCL) is associated with poor outcomes to standard salvage therapy (Crump M, et al. Blood. 2017). In SCHOLAR-1, a large multicenter, patient-level, retrospective study, patients with R/R diffuse LBCL had a 26% objective response rate (ORR) to the next line of therapy, a 7% complete response (CR) rate, and a median overall survival of 6.3 months (Crump M, et al. Blood 2017). Axicabtagene ciloleucel (axi-cel) is an autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy approved for patients with R/R LBCL with ≥ 2 prior systemic therapies. With a median follow-up of 27.1 months in ZUMA-1, the ORR with axi-cel was 83% (58% CR rate) in patients with refractory LBCL (Locke FL, et al. Lancet Oncol. 2019). Activation of the costimulatory receptor 4-1BB (CD137) on CAR T cells may enhance axi-cel antitumor activity by enhancing T cell proliferation, function, and survival. Utomilumab (uto), an investigational monoclonal antibody agonist of the 4-1BB pathway, enhanced T cell function and survival in preclinical studies (Fisher TS, et al. Cancer Immunol Immunother. 2012) and had favorable single-agent safety in patients (Segal NH, et al. Clin Cancer Res. 2018). Possible mechanisms of resistance to axi-cel are thought to be suboptimal CAR T cell expansion an exclusionary tumor microenvironment and CD19 target antigen loss (Neelapu SS, et al. Blood 2017, Rossi JM, et al J Immunother Cancer. 2018). Combination strategies that increase proliferation, expansion, and persistence of CAR T cells or prevent activation-induced cell death of CAR T cells may improve clinical outcomes observed with axi-cel. ZUMA-11 is a Phase 1/2 study investigating the efficacy and safety of axi-cel + uto in patients with refractory LBCL. Methods: The primary objectives of this study are to determine the safety, recommended Phase 2 dosing and timing (Phase 1), and efficacy (Phase 2) of axi-cel + uto in adult patients with refractory LBCL. Patients with progressive or stable disease as the best response to second-line chemotherapy or relapse ≤ 12 months after autologous stem cell transplantation, a prior anti-CD20 antibody and anthracycline-containing regimen, and Eastern Cooperative Oncology Group performance status 0-1 are eligible. Patients with histologically proven primary mediastinal B cell lymphoma, history of Richter's transformation or chronic lymphocytic lymphoma, prior CAR T cell therapy, or central nervous system involvement of lymphoma are ineligible. In Phase 1, ≈24 patients in ≤ 3 cohorts will receive a single dose of axi-cel and escalating doses of uto (10, 30, or 100 mg) using a 3 + 3 design in up to 4 of 6 cohorts. The recommended uto dose will be based on dose-limiting toxicities and other factors. Patients will be leukapheresed and may receive optional, nonchemotherapy bridging therapy per investigator decision. After conditioning chemotherapy, patients will receive a single infusion of axi-cel (target dose, 2 × 106 CAR T cells/kg) on Day 0 followed by uto on Day 1 and every 4 weeks for 6 months or until progressive disease. Patients will be treated one at a time during Phase 1, and patients treated with axi-cel will be staggered by ≥ 2 weeks. Day 21 uto administration will be explored if toxicity is unacceptable with Day 1 administration. The primary endpoints are incidence of dose-limiting toxicities in Phase 1 and CR rate in Phase 2. Secondary endpoints include ORR, duration of response, progression-free survival, overall survival, safety, and levels of CAR T cells and cytokines in blood. This study uses a single-arm design to estimate the true CR rate; with a sample size of 27 patients, of which ≤ 3 patients will have been treated in the Phase 1 portion, the maximum half-width of the 95% confidence interval about response will be ≥ 21%. ZUMA-11 is open and accruing patients. Disclosures Reshef: Kite, a Gilead Company: Consultancy, Honoraria, Research Funding; Celgene: Research Funding; Incyte: Consultancy, Research Funding; Shire: Research Funding; BMS: Consultancy; Atara: Consultancy, Research Funding; Magenta: Consultancy; Pfizer: Consultancy; Pharmacyclics: Consultancy, Research Funding. Miklos:Pharmacyclics: Consultancy, Patents & Royalties, Research Funding; Precision Bioscience: Consultancy; Adaptive Biotechnologies: Consultancy, Research Funding; Miltenyi: Consultancy, Research Funding; Becton Dickinson: Consultancy; Janssen: Consultancy; AlloGene: Consultancy; Novartis: Consultancy; Kite, A Gilead Company: Consultancy, Research Funding; Celgene-Juno: Consultancy. Timmerman:Spectrum Pharmaceuticals: Research Funding; Kite, A Gilead Company: Consultancy, Honoraria, Other: travel support, Research Funding; ImmunGene: Research Funding; Merck: Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Other: travel support, Research Funding. Jacobson:Novartis: Consultancy, Honoraria, Other: travel support; Bayer: Consultancy, Other: travel support; Precision Biosciences: Consultancy, Other: travel support; Humanigen: Consultancy, Other: travel support; Celgene: Consultancy, Other: travel support; Pfizer: Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Other: travel support. Bennani:Kite, A Gilead Company: Consultancy, Research Funding. Rossi:Kite, A Gilead Company: Employment. Sherman:Kite, A Gilead Company: Employment. Sun:Kite, A Gilead Company: Employment. Palluconi:Kite, A Gilead Company: Employment. Kim:Kite, A Gilead Company: Employment. Jain:Kite/Gilead: Consultancy.

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Low Levels of Neurologic Toxicity with Retained Anti-Lymphoma Activity in a Phase I Clinical Trial of T Cells Expressing a Novel Anti-CD19 CAR

Blood ◽

10.1182/blood-2018-99-113731 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 697-697 ◽

Cited By ~ 4

Author(s):

Jennifer Brudno ◽

Steven Hartman ◽

Norris Lam ◽

David F. Stroncek ◽

John M. Rossi ◽

...

Keyword(s):

Clinical Trial ◽

T Cells ◽

T Cell ◽

B Cell ◽

Research Funding ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Antigen Recognition ◽

Car T Cells ◽

Car T

Abstract Anti-CD19 chimeric antigen receptor (CAR) T cells have powerful activity against B-cell lymphoma, but improvement is clearly needed. Toxicity, including cytokine-release syndrome (CRS) and neurologic toxicity, occurs after anti-CD19 CAR T cell infusions. Most CAR T-cell toxicity is caused, either directly or indirectly, by cytokines or other proteins that are secreted from CAR T cells. The structure of a CAR is an extracellular antigen-recognition domain connected by hinge and transmembrane (TM) domains to intracellular T-cell signaling moieties. In vitro, T cells expressing CARs with hinge and TM domains from the CD8-alpha molecule released significantly lower levels of cytokines compared with T cells expressing CARs with hinge and TM domains from CD28; however, T cells expressing CARs with hinge and TM domains from CD8-alpha retained sufficient functional capability to eradicate tumors from mice (Alabanza et al. Molecular Therapy. 2017. 25(11) 2452). To reduce cytokine production with a goal of reducing clinical toxicity, we incorporated CD8-alpha hinge and TM domains into an anti-CD19 CAR. The CAR also had a human antigen-recognition domain, a CD28 costimulatory domain, and a CD3-zeta domain. This CAR was designated Hu19-CD828Z and was encoded by a lentiviral vector. Hu19-CD828Z was different from the FMC63-28Z CAR that we used in prior studies. FMC63-28Z had hinge and TM domains from CD28 along with a CD28 costimulatory domain, a CD3-zeta domain, and murine-derived antigen-recognition domains. Twenty patients with B-cell lymphoma were treated on a phase I dose-escalation clinical trial of Hu19-CD828Z T cells (Table). Patients received low-dose cyclophosphamide and fludarabine daily for 3 days on days -5 to -3. Two days later, on day 0, CAR T cells were infused. The overall response rate (ORR) after 1st treatments with Hu19-CD828Z T cells was 70%, and the complete response (CR) rate 55%; the 6-month event-free survival was 55%. The anti-lymphoma activity of Hu19-CD828Z T cells in the current trial was comparable to the anti-lymphoma activity of FMC63-28Z T cells in a similar prior trial that also enrolled patients with advanced B-cell lymphoma. In the prior trial, we observed a 73% ORR, a 55% CR rate, and a 6-month event-free survival of 64% in 22 patients treated with FMC63-28Z T cells (Kochenderfer et al. Journ. Clin. Oncology. 2017 35(16) 1803). In our previous clinical trial of FMC63-28Z T cells, the rate of Grade 3 or 4 neurologic toxicity among 22 patients treated was 55%. Strikingly, in our trial of Hu19-CD828Z T cells, the rate of Grade 3 or 4 neurologic toxicity was only 5% (1/20 patients). In addition, the rate of Grade 2 or greater neurologic toxicity with FMC63-28Z T cells was 77.3% while the rate of Grade 2 or greater neurologic toxicity with Hu19-CD828Z T cells was 15%. To explore the mechanism for the difference in neurologic toxicity in patients receiving FMC63-28Z T cells versus Hu19-CD828Z T cells, we assessed serum levels of 41 proteins in patients treated with these CAR T-cells. This comparison is valid because the same Luminex methodology was used for the serum protein analysis for both trials, and controls of known amounts of each protein were assayed to ensure that protein levels were comparable on the different trials. Lower levels of several serum proteins that might be important in CAR toxicity were found in patients treated with Hu19-CD828Z T cells versus patients treated with FMC63-28Z T cells: Granzyme A (P<0.001), Granzyme B (P<0.001), interferon gamma (P=0.011), interleukin (IL)-15 (P=0.007), IL-2 (P=0.0034), and macrophage inflammatory protein-1A (P<0.001). Median peak patient blood CAR+ cell levels were 44 cells/µL for Hu19-CD828Z and 46.5 cells/µL for FMC63-28Z (P=not significant). We hypothesize that lower levels of potentially neurotoxic proteins in patients receiving Hu19-CD828Z T cells versus FMC63-28Z T cells led to a lower frequency of neurologic toxicity in patients receiving Hu19-CD828Z T cells. The lower levels of immunologically active proteins found in the serum of patients receiving Hu19-CD828Z T cells compared with patients receiving FMC63-28Z T cells is consistent with our in vitro experiments showing lower cytokine production by T cells expressing CARs with CD8 hinge and TM domains versus CD28 hinge and TM domains. Altering CAR hinge and TM domains can affect CAR T-cell function and is a promising approach to improve the efficacy to toxicity ratio of CAR T-cells. Disclosures Rossi: KITE: Employment. Shen:Kite, a Gilead Company: Employment. Xue:Kite, a Gilead Company: Employment. Bot:KITE: Employment. Rosenberg:Kite, a Gilead Company: Research Funding. Kochenderfer:Kite a Gilead Company: Patents & Royalties: CAR technology, Research Funding; Celgene: Research Funding.

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Identification of LAG3+ T Cell Populations in the Tumor Microenvironment of Classical Hodgkin Lymphoma and B-Cell Non-Hodgkin Lymphoma

Blood ◽

10.1182/blood-2020-141462 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 19-19

Author(s):

Katsuyoshi Takata ◽

Tomohiro Aoki ◽

Lauren C. Chong ◽

Katy Milne ◽

Tomoko Miyata-Takata ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Hodgkin Lymphoma ◽

Research Funding ◽

Cell Lymphoma ◽

Expression Patterns ◽

B Cell Lymphoma ◽

Cell Populations ◽

Classical Hodgkin Lymphoma

Background: LAG3 is one of the immune check point receptors that are expressed on activated cytotoxic T-cells and regulatory T cells. Physiologically, T-cell proliferation and memory T-cell differentiation is negatively regulated by LAG3-MHC interaction. In cancer tissues, T-cells that are chronically exposed to tumor antigens might upregulate LAG3 and receive inhibitory stimuli to enter an exhaustion state limiting anti-tumor immune responses. Currently, clinical trials using double blockade of LAG3/PD1 are active in several solid tumours, but there are only a small number of clinical trials using LAG3 monoclonal antibodies in lymphoma. Recently, we published a characteristic LAG3+ T-cell population as a mediator of immune suppression in classical Hodgkin lymphoma (Aoki & Chong et al. Cancer Discovery 2020). However, the abundance and variability of LAG3 positive T-cell populations across a spectrum of B-cell lymphoma has not been well studied and it remains an open question if LAG3 expression is associated with treatment outcome under standard-of-care conditions. Methods: We performed a LAG3 immunohistochemical (IHC) screen in a large cohort of B-cell Non-Hodgkin lymphoma (diffuse large B-cell lymphoma (DLBCL); N=341, follicular lymphoma (FL); N=198 (grade 1-3A), transformed FL to aggressive lymphoma (tFL); N=120, mantle cell lymphoma (MCL); N=179, primary mediastinal large B-cell lymphoma (PMBCL); N=61) and classical Hodgkin lymphoma (HL; N=459) to assess LAG3 expression in the tumor microenvironment (TME). Moreover, we characterized LAG3+ T-cell populations using multi-color immmunohistochemistry (IHC) (LAG3, PD1, CD4, CD8, FOXP3, CD20) in various lymphoma subtypes. Clinical parameters including treatment outcome were correlated with the abundance of LAG3+ T-cell populations in the TME. Results: On average, HL (7%) and PMBCL (6%) showed higher LAG3+ cellular frequency than the other B-cell lymphoma subtypes studied (DLBCL and FL: 2%, MCL: 0.8%). Comparing the frequency of LAG3+ cells according to MHC class I/II status, DLBCL showed a significant correlation with MHC class I status, and LAG3 expression correlated with MHC class II status in HL. Next, we performed multi-color IHC to describe subtype-specific expression patterns of LAG3 in T cell subsets. LAG3+PD1- T-cells were predominantly found in HL and PMBCL with only rare LAG3+PD1+ cells in HL. The majority of LAG3+ T-cells co-expressed CD4 in HL, in contrast to CD8 in PMBCL. DLBCL showed a mixed population pattern with a 1:1 ratio of LAG3+PD1- and LAG3+PD1+ T-cells. In FL, the majority of LAG3+ T-cells were CD4+PD1+, suggesting a more exhausted TME phenotype in FL than in other lymphoma subtypes. Cellular distance analysis showed that LAG3+CD4+ T-cells were in close vicinity to CD20+ lymphoma cells in FL, while in DLBCL and PMBCL, the nearest neighbors of malignant cells were LAG3+CD8+. Triple-positive LAG3+PD1+CD8+ T-cells significantly correlated with high infiltrating M2 macrophage (Pearson's correlation test, P < 0.001) content and the ABC cell-of-origin subtype (Pearson's correlation test, P = 0.002) in DLBCL. The abundance of LAG3+CD8+PD1- cells correlated with a high FLIPI score (Pearson's correlation test, P = 0.033), disease specific survival (HR = 2.8, 95% CI = 1.3-5.9, P = 0.006), time to progression (HR = 2.8, 95% CI = 1.6-5.0, P = 0.001) and transformation (HR = 4.0, 95%CI = 1.7-9.6, P = 0.002) in FL treated with R-CVP (N = 135). Assessing LAG3 expression by single color IHC in FL (cut-off at 5%), patients with LAG3-positive samples showed significantly higher FL transformation rates (P = 0.023) and tFL samples showed higher abundance of LAG3+ cells than the corresponding primary pretreatment FL samples (primary FL: 1.5±1.7% vs. tFL: 4.2±3.8%, t-test, P = 0.01). The increased transformation risk was validated in an independent FL cohort treated with R-CHOP/CVP (N=97, HR = 6.2, 95% CI = 2.8-13.9, P < 0.001). Conclusion: The highest abundance of LAG3+ T-cells in the TME was found in HL and its related entity PMBCL. The differential outcome correlations and co-expression patterns in LAG3+ T cells across B-cell lymphoma subtypes indicate heterogeneity in TME composition and related pathogenic mechanisms. Our results suggest that LAG3 expression patterns will be important in the interpretation of ongoing studies and highlight populations that may benefit from LAG3 checkpoint inhibition. Disclosures Sehn: AstraZeneca: Consultancy, Honoraria; Genentech, Inc.: Consultancy, Honoraria, Research Funding; Amgen: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Chugai: Consultancy, Honoraria; TG therapeutics: Consultancy, Honoraria; Verastem Oncology: Consultancy, Honoraria; Teva: Consultancy, Honoraria, Research Funding; Servier: Consultancy, Honoraria; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; MorphoSys: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Apobiologix: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Kite: Consultancy, Honoraria; Merck: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Acerta: Consultancy, Honoraria. Savage:Merck, BMS, Seattle Genetics, Gilead, AstraZeneca, AbbVie, Servier: Consultancy; BeiGene: Other: Steering Committee; Roche (institutional): Research Funding; Merck, BMS, Seattle Genetics, Gilead, AstraZeneca, AbbVie: Honoraria. Scott:Celgene: Consultancy; Abbvie: Consultancy; AstraZeneca: Consultancy; NIH: Consultancy, Other: Co-inventor on a patent related to the MCL35 assay filed at the National Institutes of Health, United States of America.; Roche/Genentech: Research Funding; NanoString: Patents & Royalties: Named inventor on a patent licensed to NanoString, Research Funding; Janssen: Consultancy, Research Funding. Steidl:Bayer: Consultancy; Juno Therapeutics: Consultancy; Roche: Consultancy; Seattle Genetics: Consultancy; Bristol-Myers Squibb: Research Funding; AbbVie: Consultancy; Curis Inc: Consultancy.

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MyD88 L265P Mutation-Specific TCR Gene Therapy for Treatment of B-Cell Lymphoma and Leukemia

Blood ◽

10.1182/blood-2020-142880 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 5-5

Author(s):

Özcan Çinar ◽

Peter Michael Kloetzel ◽

Caroline Anna Peuker ◽

Ulrich Keller ◽

Antonio Pezzutto ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Cell Lines ◽

Research Funding ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Myd88 L265p Mutation ◽

T Cell Lines ◽

Myd88 L265p

Adoptive transfer of engineered T cells has shown remarkable success in hematopoietic malignancies. However, the current most common strategy of targeting lineage-specific antigens often leads to undesirable side effects and a high relapse rate. Therefore, novel treatment approaches are still needed. Oncogenic somatic mutations represent ideal targets because of tumor specificity: such (neo)antigens can be recognized by T cell receptors (TCR) in the context of MHC-peptide presentation. Here we have generated T cell lines from multiple healthy donors targeting one of the most common driver mutations found in B-cell lymphomas; a missense mutation on adaptor protein MyD88 changing leucine at position 265 to proline (L265P). T cell lines generated by autologous in vitro priming were reactive selectively against the predicted mutant epitope restricted to HLA-B7, but not against the corresponding wild-type peptide. Cloned TCRs from these lines led to mutation-specific and HLA-restricted reactivity with varying functional avidity. T cells engineered with mutation-specific TCR (TCR-T cells) recognized and killed cell lines of diffuse large B-cell lymphoma characterized by intrinsic MyD88 L265P. Furthermore, TCR-T cells showed promising therapeutic efficacy in xenograft mouse models, while initial safety screening did not indicate any sign of cross- or allo-reactivity risk. Taken together, our data suggest that mutation-specific TCRs can be used to target MyD88 L265P mutation, and hold promise for precision therapy for a significant subgroup of B-cell malignancies. Disclosures Keller: Bristol Myers Squibb: Honoraria, Other: Travel support, Speakers Bureau. Busse:Daiichi Sankyo: Other: Travel Support; Hexal: Honoraria, Research Funding; Roche: Honoraria; BMS: Honoraria; Novartis: Research Funding.

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Anti-CD27 Enhances Lymphoma Immunotherapy through Profound Myeloid Cell Recruitment

Blood ◽

10.1182/blood.v128.22.3024.3024 ◽

2016 ◽

Vol 128 (22) ◽

pp. 3024-3024

Author(s):

Anna H Turaj ◽

Vikki L Field ◽

Claude H.T. Chan ◽

Christine A. Penfold ◽

Jinny H. Kim ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Nk Cells ◽

Research Funding ◽

Therapeutic Potential ◽

Cell Lymphoma ◽

Myeloid Cells ◽

B Cell Lymphoma ◽

Anti Cd20

Abstract Direct-targeting monoclonal antibodies (mAb) such as anti-CD20 mAb are thought to elicit their anti-tumor function through antibody-dependent cellular phagocytosis (ADCP) mediated by myeloid cells (monocytes and macrophages), with little involvement of T cells. In contrast, immunomodulatory mAbs to TNFR superfamily members, CD27, OX40 and CD137, function by augmenting T-cell responses. We examined the therapeutic potential of combining anti-CD20 mAb with a panel of immunomodulatory mAbs (OX40, CD137, CD27, TIGIT, GITR, CTLA4, PD-1). In the syngeneic BCL1 B-cell lymphoma mouse model only an agonistic mAb to CD27, provided a synergistic effect when combined with anti-CD20. Anti-CD20 and anti-CD27 mAb individually provided modest therapeutic benefit (median survival 33 days and 62 days, respectively), but mice treated with the combination survived beyond 100 days. Similar synergistic survival benefit was observed in another B-cell lymphoma model, A31, and in BCL1-bearing human CD27 transgenic mice, when anti-CD20 was combined with varlilumab, an anti-human CD27 mAb currently under clinical investigation. We observed that in mice treated with anti-CD27, there was an early and substantial increase in intra-tumoral monocyte, neutrophil and macrophage infiltration. CD27 is expressed constitutively on T and NK cells but not myeloid cells or the tumor itself. To investigate whether CD27 agonism promotes intra-tumoral myeloid cell infiltration through T cells, we depleted T cells in the BCL1model. Surprisingly, CD4 or CD8 T-cell depletion had no effect on the survival of anti-CD20 and anti-CD27-treated mice, suggesting that the remaining CD27+ immune effector cells, NK cells, are required. To further probe the relative importance of these two sub-sets, we performed experiments in γ chain knockout mice, where activatory FcγR are not expressed. Here, anti-CD27 mediated T-cell activation can still occur via crosslinking from the inhibitory FcγRII, but effector function through NK cells, mediated through activatory FcγR, is abrogated. In this model, the therapeutic benefit of anti-CD27 was completely abolished, thereby supporting the requirement for NK cells. We hypothesize that anti-CD27 stimulates CD27+ NK cells to release chemokines that draw myeloid cells into the tumor, where they subsequently perform augmented anti-CD20 mediated ADCP. These data demonstrate the clear therapeutic potential of combining direct targeting and immunomodulatory mAb but that the therapeutic mechanism of action may differ to that expected; here involving a previously unheralded effect of anti-CD27 on myeloid infiltration. Based upon these data, we have implemented a phase II clinical trial examining rituximab and varlilumab in B-cell lymphoma, which will commence recruitment shortly. Disclosures Keler: Celldex Therapeutics: Employment, Equity Ownership. Johnson:Celldex Therapeutics: Research Funding. Al-Shamkhani:Celldex Therapeutics: Patents & Royalties: On therapeutic use of antibodies targeting anti-CD27 and another applied for anti-CD20/anti-CD27 use, Research Funding. Glennie:Celldex Therapeutics: Patents & Royalties: Patent on therapeutics use of antibodies targeting human CD27 and patent for anti-CD20+anti-CD27 applied. Cragg:Baxalta: Consultancy; Gilead Sciences: Research Funding; GSK: Research Funding; Roche: Consultancy, Research Funding; Bioinvent International: Consultancy, Research Funding. Lim:Celldex Therapeutics: Patents & Royalties: Patent for anti-CD20+anti-CD27 applied, Research Funding.

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Phase I Dose-Escalation Trial of CD19/CD20 Bispecific Chimeric Antigen Receptor (CAR) T-Cells for the Treatment of Relapsed or Refractory B-Cell Lymphomas and Chronic Lymphocytic Leukemia

Blood ◽

10.1182/blood-2020-137630 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 19-20

Author(s):

Sanaz Ghafouri ◽

Christopher Walthers ◽

Mobina Roshandell ◽

Brenda Ji ◽

Jacqueline Trent ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

B Cell ◽

Research Funding ◽

Cell Lymphoma ◽

B Cell Lymphoma ◽

Publicly Traded ◽

Car T Cells ◽

Car T Cell ◽

Car T

Background: Single-input anti-CD19 CAR T-cells have demonstrated clinical efficacy for relapsed or refractory (R/R) non-Hodgkin B-cell lymphoma (NHL) and chronic lymphocytic leukemia (CLL). Despite excellent response rates, over 50% of CD19 CAR T-cell recipients relapse. Preclinical data show engineering of bispecific anti-CD19/CD20 CAR T-cells via lentiviral transduction effectively targets tumor cells and overcomes antigen escape (Zah E et al., Cancer Immunol Res, 2016). Based on these promising preclinical results and the limitations of single-input anti-CD19 CARs, we investigated the bispecific anti-CD19/CD20 CAR naïve/memory T-cells in a phase I dose-escalation clinical trial for patients with R/R NHL/CLL (NCT04007029). Methods: This trial includes patients who have measurable disease after 2 lines of therapy for diffuse large B-cell lymphoma (DLBCL) and primary mediastinal B-cell lymphoma (PMBCL), and after 3 lines of therapy for mantle cell lymphoma (MCL), follicular lymphoma (FL), CLL and small lymphocytic leukemia (SLL). Eligible participants received lymphodepleting chemotherapy with fludarabine 30 mg/m2 and cyclophosphamide 500 mg/m2 for three days, followed by anti-CD19/CD20 CAR T-cell infusion. The CAR T-cell infusion will be given with standard "3+3" dose escalation to determine the maximum tolerated dose (MTD), with a dose range of 5 x 107 to 6 x 108 CAR-positive cells per patient. Results: To date, three patients received treatment on cohort 1 with 5 x 107 CD19/CD20 CAR T-cells for R/R MCL, FL and PMBCL, with an average age of 49.3 (range, 29-60) and a mean of 3.7 prior regimens (range, 3-4). All 3 patients' lymphomas were CD19+/CD20+ on tissue biopsy prior to CAR infusion and all 3 received bridging chemotherapy. The infusion was well tolerated and no major infusion reactions occurred. Peak expansion was noted on day 14. No dose limiting toxicities were identified. The maximum grade CRS was 1 and there was no ICANS. At the 6.0-month cutoff date, 2 of the 3 patients remain in ongoing complete remission. Unfortunately, one patient developed progressive disease 0.5 months after CAR infusion, yet remains alive after treatment with immunotherapy. Both of the responders continue to demonstrate ongoing CAR T-cell persistence and B-cell aplasia by 3.0 and 6.0-month follow up, respectively. Conclusions: Here we demonstrate impressive responses in 2 of 3 patients at the 5 x 107 CD19/CD20 CAR T-cell dosages. Bispecific CD19/CD20 CAR T-cell therapy appears to be safe and effective in patients with R/R NHL and CLL and obviates the challenges with the single antigen directed CARs by decreasing risk of target antigen loss and expression downregulation. A longer follow up period is required to determine the impact of modifying naïve/memory T cells and the durability of response. The trial continues to enroll patients and additional clinical and translational data are being collected on the initial patient cohort. Disclosures Timmerman: Corvus: Current equity holder in publicly-traded company; Marker Therapeutics: Current equity holder in publicly-traded company; Bluebird Bio: Current equity holder in publicly-traded company; Immune Design: Honoraria; Celldex Therapeutics: Consultancy; Valor: Research Funding; Merck: Research Funding; Spectrum Pharmaceuticals: Research Funding; BMS: Other: Travel support, Research Funding; Kite, a Gilead Company: Consultancy, Other: Travel support, Research Funding; Genmab: Current equity holder in publicly-traded company. Chen:Kalthera Therapeutics: Other: Co-founder; Notch Therapeutics: Membership on an entity's Board of Directors or advisory committees; Gritstone Oncology: Membership on an entity's Board of Directors or advisory committees. Larson:BMS, Bioline, Celgene, Juno, Janssen: Research Funding; TORL Biotherapeutics: Current equity holder in private company.

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