scholarly journals Efficient Targeting of CD38 in Mature T-Cell Neoplasms with Daratumumab and Allogeneic NK Cells

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2408-2408
Author(s):  
William T. Johnson ◽  
Colleen Isabelle ◽  
Ashley N Vogel ◽  
Jonathan E Brammer ◽  
Amy E Boles ◽  
...  

Abstract Introduction: Mature T-cell neoplasms (MTCN) are a heterogeneous and aggressive group of lymphoid neoplasms with very limited options for precision immunotherapy. Targeted immunotherapy with antibodies directed against surface markers on tumor cells has emerged as an effective treatment for B-cell neoplasms, but the development of immunotherapy strategies for MTCN has been much slower. CD38 is expressed at low levels in a subset of normal resting T-cells. Data on the frequency and level of CD38 expression is MTCN are lacking. Our goal was to study the expression and stability of CD38 on a spectrum of neoplastic T-cell populations and assess the potential anti-tumor effect of anti-CD38 monoclonal antibodies in combination with allogeneic natural killer (NK) cells in MTCN. Methods and results: We searched the Thomas Jefferson University Hospital (TJUH) pathology records for all cases of MTCN for which immune-phenotypical characterization of the neoplastic T-cell population by multi-color flow cytometry (FC) was available. CD38 expression was evaluated in cases where an abnormal T-cell population (defined as loss of one on more pan T-cell markers and/or a skewed CD4 to CD8 ratio). A total of 103 unique patients with MTCN were identified. Of these, 51 had at least one biopsy whereby tumor cells had an abnormal immunophenotype which could then be assessed for CD38 expression. CD38 was expressed to some extent in all but 2 cases with expression levels on peripheral T-cell lymphoma-not other specified (PTCL-NOS)(% Mean±SEM = 80.84±10.26, N=11), angioimmunoblastic T-cell lymphoma (AITL) (% Mean±SEM = 80.56±7.34, N=6), nodal PTCL with T follicular-helper (T FH) phenotype (% Mean±SEM = 55.00±12.72, N=7), anaplastic large cell lymphoma (ALCL) (% Mean±SEM = 77.38±10.75, N=3), large granular lymphocytic leukemia (LGLL) (% Mean±SEM = 80.27±7.49, N=4), T-cell prolymphocytic leukemia (T-PLL) (% Mean±SEM = 88.26±4.20, N=7), cutaneous T-cell lymphoma (CTCL) (% Mean±SEM = 49.52±14.77, N=7), adult T-cell leukemia/lymphoma (ATLL) (% Mean±SEM = 76.68±10.45, N=3), hepatosplenic T-cell lymphoma/monomorphic epitheliotropic intestinal T-cell lymphoma (HSTCL/MEITL) (% Mean±SEM = 75.00±11.37, N=3). The medians and ranges of the MFI of CD38 on CD38+ tumor cells were the following: PTCL-NOS 29.46 (3.1-115.62), AITL 13.64 (2.67-29.41), other PTCL-T FH 5.87 (0-48.67), ALCL 11.13 (3.6-11.28), LGL (13.52 (9.72-18.25), T-PLL 6.49 (3.09-18), CTCL 8.36 (0-116.75), ATLL 27.17 (3.54-60.5), HSTCL/MEITL 15.96 (6.96-167.85). We also measured surface expression of CD38 on the patient-derived MTCN cell lines HuT-78, HuT-102, Jurkat, H9, HH, and MOTN1, all of which expressed CD38, to determine which of these cell lines could be used for in vitro experiments. We next evaluated if the CD38 molecule is an effective target for antibody-mediated therapy in MTCN, by testing the ability of daratumumab (dara) to enhance antibody-dependent cellular cytotoxicity (ADCC) elicited by NK cells. For this, we purified normal NK-cells from TJUH Blood Bank leukoreduction filters and cultured with recombinant IL-15 for 48 hours prior to all experiment. T-cell lines and primary MTCN cells were treated with increasing concentrations (0.1 µg/mL - 2 µg/mL) of dara or isotype control. NK-cells were added at Effector:Target ratio of 5:1 and incubated for 4 hours at 37⁰ Celsius. Cytotoxicity was measured by LDH release assay. Dara induced significant cell lysis starting at doses as low as 0.1μg/mL in both T-cell lines and primary MTCN cells, reaching maximum cytotoxicity at 0.5-2μg/mL (mean±SEM cytotoxicity in isotype vs dara treated cells= 50.0±5.05% vs 97.5±2.5%, N=4, p-value=0.0002). The degree of ADCC induction also correlated with interferon-gamma (IFN-g) release by NK cells in vitro for both T-cell lines and primary MTCN cells. Conclusions: The majority of MTCN analyzed (N=49, 96%) showed any degree of CD38 expression by FC with a wide variation of intensity, including within the same subtype. Allogeneic NK cells efficiently elicited dara-mediated ADCC of tumor cells from all MTCN subtypes and produced abundant IFN-g. These data highlight the potential of targeting CD38 in MTCN with anti-CD38 antibodies and allogeneic NK cells. The strong CD38 expression observed in most tumor cells from ultra-rare and very aggressive subtypes of MTCL opens the door to much needed new treatment strategies. Disclosures Brammer: Celgene: Research Funding; Kymera Therapeutics: Consultancy; Seattle Genetics: Speakers Bureau. Chakravarti: Kiadis Pharma: Patents & Royalties. Porcu: Viracta: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Innate Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BeiGene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Research Funding; Daiichi: Honoraria, Research Funding; Kiowa: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Spectrum: Consultancy; DrenBio: Consultancy.

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4356-4356
Author(s):  
John S Manavalan ◽  
Ipsita Pal ◽  
Aidan Pursley ◽  
George A. Ward ◽  
Tomoko Smyth ◽  
...  

Abstract Background: The PTCL are a heterogeneous group of non-Hodgkin lymphomas originating from mature T-lymphocytes. They are aggressive diseases, often resistant to conventional chemotherapy. Despite the fact that a number of new agents have been approved, treatment paradigms tailored to the biology of the disease have yet to emerge. Tolinapant (ASTX660) is a potent antagonist of both cellular and X-linked inhibitors of apoptosis proteins (cIAP1/2 and XIAP), and is presently in phase I/II trials in patients with advanced solid tumors and lymphomas (NCT02503423). IAP antagonists enhance tumor necrosis factor (TNF) receptor superfamily mediated apoptosis (Ward GA, et al. Mol Cancer Ther. 2018), are potent anti-tumor immune enhancers and induce markers of immunogenic cell death such as damage associated molecular patterns (DAMPs; Ye W, et al, Oncoimmunology, 2020). Objectives: We explored the sensitivity of a range of T-cell lymphoma (TCL) cell lines to tolinapant. We establish the synergy coefficient between tolinapant and the HDAC inhibitor, romidepsin, and interrogated the molecular basis of their synergistic interaction. Methods: A panel of human T-cell lymphoma cell lines were tested in proliferation assays (CellTiterGlo) for sensitivity to tolinapant in the presence or absence of 10ng/ml of TNF alpha. For combination studies, with tolinapant and romidepsin, each drug was tested at the IC10 and IC40 concentrations in the presence or absence of TNF alpha. Synergy scores using the Excess over Bliss (EOB) model were calculated using SynergyFinder (Aleksandr Ianevski et al; Nucleic Acids Research, 2020). Additionally, the effects of tolinapant and romidepsin on the IAPs and caspases were analyzed by western blots. TNFR1 receptor expression and induction of DAMPs were also analyzed by flow cytometry. Results: TCL Lines demonstrated varying sensitivities to tolinapant in the presence or absence of TNF alpha. The most sensitive cell lines, ALK+ ALCL and SUP-M2, had IC50 concentrations ranging from 200nM ± 100nM to 20nM ± 1nM in the absence or presence of TNF alpha, respectively, at 24, 48 and 72hrs, while a resistant CTCL cell line HH had an IC50 concentration of over 20mM, even in the presence of TNF alpha. Interestingly, using western blot analysis, we found that the presence of TNF alpha increased the levels of cIAP1 in the tolinapant sensitive SUP-M2 cell line, but not in the resistant HH cell line. However, there was a concentration dependent decrease in cIAP1 but not in XIAP in both cell lines treated with tolinapant. Flow cytometry analysis demonstrated that tolinapant increases the expression of TNFR1 and DAMPs in a dose dependent manner on the sensitive SUP-M2, but not in the resistant HH cells. In combination experiments, using the EOB model, tolinapant plus romidepsin was found to be synergistic in the absence of TNF alpha, at 36hrs, in both the sensitive cell line SUP-M2 and the resistant cell line HH. In the presence of TNF alpha, synergism was seen only in the sensitive cell line SUP-M2 and antagonistic in the HH cell line (Fig. 3). In the tolinapant plus romidepsin treated samples, cIAP1 levels decreased in the SUP-M2 cell line, in the absence of TNF alpha, however, addition of TNF alpha did not alter the levels of cIAP1 in the SUP-M2 cells. The cIAP1 levels decreased in the HH cells treated with the combination, in both the presence or absence of TNF alpha (Figure). Our findings indicate that the synergy of the tolinapant plus romidepsin is not dependent on the presence of TNF alpha. Conclusion: Tolinapant has demonstrated potent cytotoxic effects against a broad range of TCL lines both as a monotherapy and in combination with the HDAC Inhibitor, romidepsin. In in vitro studies, T cell lymphoma cell lines demonstrated varying sensitivity to tolinapant with certain cell lines being more resistant, even in the presence of TNF alpha. Interestingly, the addition of romidepsin appeared to overcome the intrinsic resistance to tolinapant in the absence of TNF alpha. These data provide the rationale to continue to explore the combination of tolinapant and romidepsin in vivo and to investigate additional combinations with T-cell specific agents (e.g. pralatrexate, belinostat, azacitidine and decitabine). Figure 1 Figure 1. Disclosures Smyth: Astex Pharmaceuticals: Current Employment. Sims: Astex Pharmaceuticals: Current Employment. Loughran: Kymera Therapeutics: Membership on an entity's Board of Directors or advisory committees; Bioniz Therapeutics: Membership on an entity's Board of Directors or advisory committees; Keystone Nano: Membership on an entity's Board of Directors or advisory committees; Dren Bio: Membership on an entity's Board of Directors or advisory committees. Marchi: Kyowa Kirin: Honoraria; Myeloid Therapeutics: Honoraria; Astex: Research Funding; BMS: Research Funding; Merck: Research Funding; Kymera Therapeutics: Other: Scientific Advisor.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5302-5302
Author(s):  
Rong Liang ◽  
Jian hong Wang ◽  
Fang Liu ◽  
Xiao hui Duan ◽  
Xia Cai Hao ◽  
...  

Abstract Objective: To investigate the role and mechanism of miR-30b underlying cisplatin resistance of human NK/T cell lymphoma lines SNK-6 and YTS cells. Methods: Normal NK cells and SNK-6 and YTS cells were cultured, the levels of miR-30b and CCL22 were detected by real-time PCR assay, CCL22 expression was detected by western blot analysis. Transfected with miR-30b mimics and inhibitor in SNK-6 and YTS cells respectively, and then measured the effect of cisplatin resistance in SNK-6 and YTS cells by MTT assay, the activity of caspase-3 was detected by caspase-3 kit assay, the cells apoptosis ratio was detected using flow cytometry analysis. The target relationship of miR-30b and CCL22 were determined by dual-luciferase reporter gene assay. The expressions of CCL22. Furthermore, the effect of CCL22 on cisplatin resistance and caspase-3 were also evaluated. Results: The levels of miR-30b were significantly decreased in both SNK-6 and YTS cells, but with the increase in CCL22 expression. MiR-30b mimics decreased the cells activity, down-regulated the cisplatin resistance, increased cells apoptosis ratio and caspase-3 activity. The effects of miR-30b inhibitor were contrary to the mimics. Up-regulated miR-30b significantly decreased the luciferase activity in CCL22 3'-UTR transfected NK cells, but not in Mut-CCL22 3'UTR group, suggesting that CCL22 could act as a direct target of miR-30b. The expressions of CCL22 pathway proteins were down-regulated after SNK-6 cells transfected with miR-30b mimics, while the effects were restored by overexpression of CCL22. Moreover, CCL22 overexpression also increased the cells activity and decreased caspase-3 activity when SNK-6 cells were transfected with miR-30b mimics. Conclusion: MiR-30b inhibited cisplatin resistance of human NKTCL in SNK-6 and YTS cells by targeting CCL22. Disclosures Wang: Novartis: Research Funding; Kite Pharma: Research Funding; MoreHealth: Consultancy; AstraZeneca: Consultancy, Research Funding; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Dava Oncology: Honoraria; Juno: Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta Pharma: Honoraria, Research Funding; Pharmacyclics: Honoraria, Research Funding.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 114-114 ◽  
Author(s):  
Bertrand Coiffier ◽  
Barbara Pro ◽  
H. Miles Prince ◽  
Francine M Foss ◽  
Lubomir Sokol ◽  
...  

Abstract Abstract 114 Background: Romidepsin is a potent HDAC inhibitor approved by the FDA for patients (pts) with cutaneous T-cell lymphoma who have received at least 1 prior systemic therapy. Durable clinical benefit and tolerability of romidepsin in pts with recurrent or refractory PTCL have been previously observed in a phase 2 trial conducted by the National Cancer Institute. The aim of this phase 2, single-arm, open-label registration study was to evaluate the activity of romidepsin in a larger number of pts with progressive or relapsed PTCL. Methods: Pts with histologically confirmed PTCL (PTCL NOS, angioimmunoblastic T-cell lymphoma, ALCL [ALK-1 negative], other subtypes) who failed or were refractory to ≥ 1 prior systemic therapy, and had measurable disease and ECOG performance status 0–2 were eligible. Exclusions included inadequate bone marrow or other organ function and significant cardiovascular abnormalities. Pts received romidepsin 14 mg/m2 as a 4-h IV infusion on days 1, 8, and 15 every 28 days for up to 6 cycles; treatment could be extended for stable disease (SD) or response. The primary endpoint was rate of complete response (CR + CRu) as evaluated by a central Independent Review Committee (IRC) using International Working Criteria for non-Hodgkin's lymphoma. IRC assessment consisted of a 2-step process, with initial radiographic review of images (CT, MRI) followed by an overall clinical assessment based on the radiology evaluations, photographs, and relevant clinical parameters. Secondary endpoints included objective response rate (ORR): CR + CRu + partial response (PR), investigator-assessed responses, duration of response, time to response, and safety. Results: 131 pts from 48 US, European, and Australian sites were enrolled and received at least 1 dose of romidepsin (as-treated population); 130 patients had histologically confirmed PTCL by central review. Mean age of all pts was 59.4 y (range, 20–83) and median time since diagnosis was 1.25 y (range, 0–17). Median number of prior systemic therapies was 2 (range, 1–8). 21 pts (16%) had failed a prior stem cell transplant. Responses assessed by the IRC are noted in the table below. Longest duration of response is 26+ mo and 16 (94%) of the 17 pts with a CR had not progressed as of the data cutoff (March 31, 2010). Investigator-assessed responses included 21 pts (16%) with CR + CRu, 18 pts (14%) with PR for an ORR of 30%. Currently, 13 pts continue to receive treatment (range, 10–36 cycles). Adverse events (AEs) were reported in 126 of 131 pts (96%). AEs reported in ≥ 20% of pts were nausea (59%), fatigue (41%), vomiting (38%), thrombocytopenia (38%), diarrhea (35%), pyrexia (34%), neutropenia (30%), anorexia (28%), constipation (28%), anemia (23%), and dysgeusia (21%). AEs ≥ grade 3 were reported for 86 pts (66%), with the most common (≥ 5%) being pneumonia (5%), pyrexia (5%), sepsis (5%), and vomiting (5%). 60 pts (46%) had at least 1 serious AE: the most frequently reported (≥ 5%) were pyrexia (7%), pneumonia (5%), vomiting (5%), and sepsis (5%). 22 pts (17%) withdrew due to AEs. 8 pts (6%) died within 30 days of the last dose of romidepsin; 1 death, due to sepsis, was assessed as possibly related to treatment. Conclusions: Complete and durable responses were observed with single agent romidepsin in pts with relapsed PTCL. These data support the therapeutic potential for romidepsin in relapsed PTCL and suggest that romidepsin is a strong candidate for inclusion in future novel regimens for these diseases. As of the data cutoff (March 31, 2010), the median duration of follow-up for CR is 8.2 mo. Disclosures: Coiffier: Gloucester: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau. Off Label Use: Romidepsin is indicated for the treatment of cutaneous T-cell lymphoma (CTCL) in patients who have received at least one prior systemic therapy. Romidepsin is not currently approved for the treatment of peripheral T-cell lymphoma (PTCL). Pro:Celgene: Research Funding. Prince:Celgene: Consultancy, Honoraria, Research Funding. Foss:Celgene: Consultancy; Eisai: Consultancy, Speakers Bureau; Merck: Speakers Bureau; Allos: Consultancy, Speakers Bureau; Cephalon: Speakers Bureau. Sokol:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Caballero:Celgene: Membership on an entity's Board of Directors or advisory committees. Morschhauser:Roche: Consultancy, Honoraria; Bayer: Honoraria. Padmanabhan:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Shustov:Celgene: Research Funding. Nichols:Celgene: Employment. Carroll:Celgene: Employment. Balser:Gloucester Pharmaceutical: Consultancy. Horwitz:Celgene: Consultancy, Honoraria.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1614-1614 ◽  
Author(s):  
Francine M. Foss ◽  
Kenneth R. Carson ◽  
Lauren Pinter-Brown ◽  
Steven M. Horwitz ◽  
Steven T. Rosen ◽  
...  

Abstract 1614 Background: Registries can be invaluable for describing patterns of care for a population of patients. COMPLETE is a registry of peripheral T-cell lymphoma (PTCL) patients designed to identify the lymphoma-directed treatments and supportive care measures that PTCL patients receive. We report here the first detailed findings of initial therapy. Methods: This is a prospective, longitudinal, observational registry that is led by a global steering committee. Patients with newly diagnosed PTCL and providing written informed consent are eligible. Patients are entered into the registry from time of initial diagnosis and followed for up to 5 years. Only locked records are reported. Results: As of July 2012, 330 patients have been enrolled from the United States. The first patient was enrolled in February 2010. Locked baseline and treatment records are available for 124 and 81 patients, respectively. Of the 124 patients with locked baseline records, 67 patients (54%) were male, the mean age was 59 (range: 19–89), and race/ethnicity was recorded as: White (87 patients; 70%), Black (19; 15%), Asian (5; 4%) and other/unknown (13; 11%). Histology was reported as follows: PTCL-not otherwise specified (27%), anaplastic large cell lymphoma-primary systemic type (18%), angioimmunoblastic T-cell lymphoma (17%), transformed mycosis fungoides (7%), T/NK-cell lymphoma-nasal and nasal type (6%), adult T-cell leukemia/lymphoma, HTLV 1+ (6%) and other (19%). 25 patients (20%) had received another diagnosis, including B-cell lymphoma, Hodgkin's disease and other T-cell lymphomas, prior to their current diagnosis of PTCL. 49 patients (40%) had B symptoms, 102 patients (82%) had an Ann Arbor stage of III/IV, 116 patients (94%) had ECOG performance status of 0–1, and international prognostic index (IPI) score was distributed as follows: IPI 0 (7% of patients), 1 (15%), 2 (43%), 3 (26%), and 4 (9%). Of the 81 patients with locked treatment records, details on initial treatment can be found in table below. Conclusions: This first detailed analysis of primary treatment of PTCL indicates that this disease is still largely being treated with regimens derived primarily from studies of B-cell lymphomas and that a single standard of care does not exist. The fact that a meaningful proportion of patients were initially diagnosed with something other than their current diagnosis of PTCL points out the challenges of diagnosing the disease. While the intent of initial treatment for most patients is to affect a cure, more than 20% of patients were noted as deceased at the end of initial treatment, underscoring the need for more effective, disease-specific therapy. Disclosures: Foss: Merck: Study Grant, Study Grant Other; Celgene: Study Grant, Study Grant Other; Eisai: Consultancy; Seattle Genetics: Consultancy; Celgene: Consultancy; Allos: Consultancy. Carson:Allos: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau. Pinter-Brown:Allos: Consultancy, Membership on an entity's Board of Directors or advisory committees. Horwitz:Allos: Consultancy, Research Funding. Rosen:Allos: Consultancy, Honoraria. Pro:Celgene: Honoraria, Research Funding; Spectrum: Honoraria; Allos: Honoraria; Seattle Genetics: Research Funding. Gisselbrecht:Allos: Consultancy, Membership on an entity's Board of Directors or advisory committees. Hsi:Allos: Research Funding; Eli Lilly: Research Funding; Abbott: Research Funding; Cellerant Therapeutics: Research Funding; BD Biosciences: Research Funding; Millenium: Research Funding.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 623-623
Author(s):  
Bradley M. Haverkos ◽  
Onder Alpdogan ◽  
Robert Baiocchi ◽  
Jonathan E Brammer ◽  
Tatyana A. Feldman ◽  
...  

Abstract Introduction: EBV can be associated with several types of lymphomas, with reported frequencies of up to 8-10% in diffuse large B cell lymphoma (DLBCL), 30-100% in peripheral T cell lymphoma (PTCL) subtypes, 80% in post-transplant lymphoproliferative disease (PTLD), and 15-30% in classical Hodgkin lymphoma (HL), with adverse impact on outcomes. Nanatinostat (Nstat) is a Class-I selective oral HDAC inhibitor that induces the expression of the lytic BGLF4 EBV protein kinase in EBV + tumor cells, activating ganciclovir (GCV) via phosphorylation. This results in GCV-induced inhibition of viral and cellular DNA synthesis and apoptosis. Herein we report the final results from this exploratory study for patients with R/R EBV + lymphomas (NCT03397706). Methods: Patients aged ≥18 with histologically confirmed EBV + lymphomas (defined as any degree of EBER-ISH positivity), R/R to ≥1 prior systemic therapies with an absolute neutrophil count ≥1.0×10 9/L, platelet count ≥50×10 9/L, and no curative treatment options per investigator were enrolled into 5 dose escalation cohorts to determine the recommended phase 2 doses (RP2D) of Nstat + VGCV for phase 2 expansion. Phase 2 patients received the RP2D (Nstat 20 mg daily, 4 days per week + VGCV 900 mg orally daily) in 28-day cycles until disease progression or withdrawal. Primary endpoints were safety/RP2D (phase 1b) and overall response rate (ORR) (phase 2); secondary endpoints were pharmacokinetics, duration of response (DoR), time to response, progression free survival and overall survival. Responses were assessed using Lugano 2014 response criteria beginning at week 8. Results: As of 18 June 2021, 55 patients were enrolled (phase 1b: 25; phase 2: 30). Lymphoma subtypes were DLBCL (n=7), extranodal NK/T-cell (ENKTL) (n=9), PTCL, not otherwise specified (PTCL-NOS) (n=5), angioimmunoblastic T cell lymphoma (n=6), cutaneous T cell (n=1), HL (n=11), other B cell (n=3), and immunodeficiency-associated lymphoproliferative disorders (IA-LPD) (n=13), including PTLD (n=4), HIV-associated (n=5), and other [n=4: systemic lupus erythematosus (SLE) (n=2), common variable/primary immunodeficiency (n=2)]. Median age was 60 years (range 19-84), M/F 35/20, median number of prior therapies was 2 (range 1-11), 76% had ≥2 prior therapies, 78% were refractory to their most recent prior therapy, and 84% had exhausted standard therapies. EBER positivity ranged from <1 to 90% in 42 tumor biopsies with central lab review. The most common treatment-emergent adverse events (TEAEs) of all grades were nausea (38%), neutropenia (34%), thrombocytopenia (34%), and constipation (31%). Grade 3/4 TEAEs in >10% of patients included neutropenia (27%), thrombocytopenia (20%), anemia (20%), and lymphopenia (14%). Dose reductions and interruptions due to treatment-related AEs were reported in 14 (25%) and 16 (29%) patients, respectively. Only 1 patient had to discontinue therapy. There were no cases of CMV reactivation. For 43 evaluable patients (EBER-ISH + with ≥ 1 post-treatment response assessment) across all histologies, the investigator-assessed ORR and complete response (CR) rates were 40% (17/43) and 19% (8/43) respectively. Patients with T/NK-NHL (n=15; all refractory to their last therapy) had an ORR of 60% (n=9) with 27% (n=4) CRs. Two patients (ENKTL and PTCL-NOS) in PR and CR respectively were withdrawn at 6.7 and 6.6 months (m) respectively for autologous stem cell transplantation. For DLBCL (n=6), ORR/CR was 67%/33% (both CRs were in patients refractory to first-line R-CHOP). For IA-LPD (n=13), ORR/CR was 30%/20% (PTLD: 1 CR, other: 1 CR, 1 PR). For HL (n=10), there was 1 PR (4 SD). The median DoR for all responders was 10.4 m, with a median follow-up from response of 5.7 m (range 1.9-34.1 m). For the 17 responders, 8 lasted ≥ 6 months. Conclusions: The combination of Nstat and VGCV was well-tolerated with a manageable toxicity profile and shows promising efficacy in patients with R/R EBV + lymphomas, particularly in refractory T/NK-NHL, a heterogeneous group of aggressive lymphomas with dismal outcomes, with multiple durable responses. Further evaluation of this novel combination therapy for the treatment of recurrent EBV + lymphomas is ongoing in the phase 2 VT3996-202 trial. Disclosures Haverkos: Viracta Therapeutics, Inc.: Honoraria, Research Funding. Baiocchi: Prelude Therapeutics: Consultancy; viracta: Consultancy, Current holder of stock options in a privately-held company; Codiak Biosciences: Research Funding; Atara Biotherapeutics: Consultancy. Brammer: Seattle Genetics: Speakers Bureau; Celgene: Research Funding; Kymera Therapeutics: Consultancy. Feldman: Alexion, AstraZeneca Rare Disease: Honoraria, Other: Study investigator. Brem: Karyopharm: Membership on an entity's Board of Directors or advisory committees; SeaGen: Speakers Bureau; BeiGene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees; KiTE Pharma: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Consultancy; ADC Therapeutics: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics/Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Morphosys/Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Scheinberg: Roche: Consultancy; Abbvie: Consultancy; BioCryst Pharmaceuticals: Consultancy; Alexion pharmaceuticals: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau. Joffe: AstraZeneca: Consultancy; Epizyme: Consultancy. Katkov: Viracta Therapeutics, Inc.: Current Employment. McRae: Viracta Therapeutics, Inc.: Current Employment. Royston: Viracta Therapeutics, Inc.: Current Employment. Rojkjaer: Viracta Therapeutics, Inc.: Current Employment. Porcu: Viracta: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Innate Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BeiGene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Research Funding; Daiichi: Honoraria, Research Funding; Kiowa: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Spectrum: Consultancy; DrenBio: Consultancy.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3199-3199 ◽  
Author(s):  
Subhashis Sarkar ◽  
Sachin Chauhan ◽  
Arwen Stikvoort ◽  
Alessandro Natoni ◽  
John Daly ◽  
...  

Abstract Introduction: Multiple Myeloma (MM) is a clonal plasma cell malignancy typically associated with the high and uniform expression of CD38 transmembrane glycoprotein. Daratumumab is a humanized IgG1κ CD38 monoclonal antibody (moAb) which has demonstrated impressive single agent activity even in relapsed refractory MM patients as well as strong synergy with other anti-MM drugs. Natural Killer (NK) cells are cytotoxic immune effector cells mediating tumour immunosurveillance in vivo. NK cells also play an important role during moAb therapy by inducing antibody dependent cellular cytotoxicity (ADCC) via their Fcγ RIII (CD16) receptor. Furthermore, 15% of the population express a naturally occurring high affinity variant of CD16 harbouring a single point polymorphism (F158V), and this variant has been linked to improved ADCC. However, the contribution of NK cells to the efficacy of Daratumumab remains debatable as clinical data clearly indicate rapid depletion of CD38high peripheral blood NK cells in patients upon Daratumumab administration. Therefore, we hypothesize that transiently expressing the CD16F158V receptor using a "safe" mRNA electroporation-based approach, on CD38low NK cells could significantly enhance therapeutic efficacy of Daratumumab in MM patients. In the present study, we investigate the optimal NK cell platform for generating CD38low CD16F158V NK cells which can be administered as an "off-the-shelf"cell therapy product to target both CD38high and CD38low expressing MM patients in combination with Daratumumab. Methods: MM cell lines (n=5) (MM.1S, RPMI-8226, JJN3, H929, and U266) and NK cells (n=3) (primary expanded, NK-92, and KHYG1) were immunophenotyped for CD38 expression. CD16F158V coding m-RNA transcripts were synthesized using in-vitro transcription (IVT). CD16F158V expression was determined by flow cytometry over a period of 120 hours (n=5). 24-hours post electroporation, CD16F158V expressing KHYG1 cells were co-cultured with MM cell lines (n=4; RPMI-8226, JJN3, H929, and U266) either alone or in combination with Daratumumab in a 14-hour assay. Daratumumab induced NK cell fratricide and cytokine production (IFN-γ and TNF-α) were investigated at an E:T ratio of 1:1 in a 14-hour assay (n=3). CD38+CD138+ primary MM cells from newly diagnosed or relapsed-refractory MM patients were isolated by positive selection (n=5), and co-cultured with mock electroporated or CD16F158V m-RNA electroporated KHYG1 cells. CD16F158V KHYG1 were also co-cultured with primary MM cells from Daratumumab relapsed-refractory (RR) patients. Results: MM cell lines were classified as CD38hi (RPMI-8226, H929), and CD38lo (JJN3, U266) based on immunophenotyping (n=4). KHYG1 NK cell line had significantly lower CD38 expression as compared to primary expanded NK cells and NK-92 cell line (Figure 1a). KHYG1 electroporated with CD16F158V m-RNA expressed CD16 over a period of 120-hours post-transfection (n=5) (Figure 1b). CD16F158V KHYG1 in-combination with Daratumumab were significantly more cytotoxic towards both CD38hi and CD38lo MM cell lines as compared to CD16F158V KHYG1 alone at multiple E:T ratios (n=4) (Figure 1c, 1d). More importantly, Daratumumab had no significant effect on the viability of CD38low CD16F158V KHYG1. Moreover, CD16F158V KHYG1 in combination with Daratumumab produced significantly higher levels of IFN-γ (p=0.01) upon co-culture with CD38hi H929 cell line as compared to co-culture with mock KHYG1 and Daratumumab. The combination of CD16F158V KHYG1 with Daratumumab was also significantly more cytotoxic to primary MM cell ex vivo as compared to mock KHYG1 with Daratumumab at E:T ratio of 0.5:1 (p=0.01), 1:1 (p=0.005), 2.5:1 (p=0.003) and 5:1 (p=0.004) (Figure 1e). Preliminary data (n=2) also suggests that CD16F158V expressing KHYG1 can eliminate 15-17% of primary MM cells from Daratumumab RR patients ex vivo. Analysis of more Daratumumab RR samples are currently ongoing. Conclusions: Our study provides the proof-of-concept for combination therapy of Daratumumab with "off-the-shelf" CD38low NK cells transiently expressing CD16F158V for treatment of MM. Notably, this approach was effective against MM cell lines even with low CD38 expression (JJN3) and primary MM cells cultured ex vivo. Moreover, the enhanced cytokine production by CD16F158V KHYG1 cells has the potential to improve immunosurveillance and stimulate adaptive immune responses in vivo. Disclosures Sarkar: Onkimmune: Research Funding. Chauhan:Onkimmune: Research Funding. Stikvoort:Onkimmune: Research Funding. Mutis:Genmab: Research Funding; OnkImmune: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Research Funding; Celgene: Research Funding; Novartis: Research Funding. O'Dwyer:Abbvie: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; BMS: Research Funding; Glycomimetics: Research Funding; Onkimmune: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2937-2937
Author(s):  
Thomas E. Witzig ◽  
Lubomir Sokol ◽  
Eric D Jacobsen ◽  
Won-Seog Kim ◽  
Francine M. Foss ◽  
...  

Abstract Background Tipifarnib is a potent and selective inhibitor of the enzyme farnesyltransferase (FT). FT catalyzes post-translational attachment of farnesyl groups required for localization of signaling molecules to the inner cell membrane. CXCL12 is a chemokine that is essential for T cell homing to lymphoid organs and the bone marrow, and for the maintenance of immune cell progenitors. Herein we report preliminary efficacy, safety and biomarker data from a Phase 2 study of tipifarnib in angioimmunoblastic T-cell lymphoma (AITL) and CXCL12+ peripheral T-cell lymphoma (PTCL) patients (pts). Methods This Phase 2 study is a multi-institutional, single-arm, open-label trial initially designed as a two-stage (11+7 pts) cohort to determine the efficacy, safety and biomarkers of tipifarnib in pts with relapsed/refractory (R/R) PTCL, age >/=18 years and a performance status of 0-2. Based on initial findings, the study was amended to include a cohort of AITL (n=12) and PTCL (n=12) pts with the CXCL12 rs2839695 A/A genotype (CXCL12+ cohort). Pts received tipifarnib 300 mg administered orally twice daily on days 1-21 of 28-day treatment cycles until progression of disease (PD) or unacceptable toxicity. The primary endpoint of the study is overall response rate (ORR). Ancillary studies are also ongoing to investigate the prognostic value of CXCL12 expression in patients who received standard of care treatment. Results As of 25 July 2018, 34 PTCL pts (13 AITL, 1 ALK- ALCL, 20 PTCL-NOS) have been treated with tipifarnib, 19 pts in stages 1 and 2, and 15 pts in the ongoing AITL histology and CXCL12 cohorts. Median number of prior treatment regimens was 3. The most common treatment-related adverse events (AE) (grade ≥ 3) are hematological, including neutropenia (50%), thrombocytopenia (43%), leukopenia (33%), febrile neutropenia (27%), and anemia (20%). Skin and subcutaneous tissue disorders were reported in 9 pts, 6 of them with AITL histology. One pt with AITL experienced an episode of possible Stevens Johnson Syndrome that resolved with dose discontinuation and did not recur upon re-challenge at one dose level reduction. Of 18 evaluable patients enrolled in Stages 1 and 2 of the trial, 3 partial responses (PR), 2 of them in pts with AITL histology, and 4 best responses of stable disease (SD) were observed. Pre-treatment tumor tissue CXCL12 expression correlated with favorable pt outcomes. In the AITL cohort (10 evaluable pts), 1 PR and 1 SD have been observed so far, with 5 pts pending cycle 2 response evaluation. In the CXCL12+ cohort (n=3 evaluable pts), 1 SD has been observed, with 2 pts pending cycle 2 response evaluation. Plasma levels of CXCL12 decreased over time with tipifarnib treatment. Expression of CXCL12 mRNA and other biomarkers in pre-treatment biopsies of pts in the AITL and CXCL12+ cohorts are being evaluated using RT-PCR assays. In addition, the prognostic value of CXCL12 is being investigated in approximately 100 diagnostic specimens of PTCL pts who received standard therapy. Preliminary data suggest that CXCL12 overexpression is observed in approximately 25% of PTCL and negatively affects pt survival. Conclusion Preliminary activity of tipifarnib was observed in PTCL pts, particularly in those with tumors of AITL histology and high CXCL12 expression and enrollment continues. Disclosures Witzig: Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Sokol:Mallinckrodt Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy; Spectrum Pharmaceuticals: Consultancy. Jacobsen:Merck: Consultancy; Seattle Genetics: Consultancy. Kim:Takeda: Research Funding; J&J: Research Funding; Mundipharma: Research Funding; Roche: Research Funding; Novartis: Research Funding; Kyowa-Kirin: Research Funding; Celltrion: Research Funding. Foss:Miragen: Consultancy, Speakers Bureau; Spectrum: Consultancy; Seattle genetics: Consultancy; Mallinkrodt: Consultancy. Advani:Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board, Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Kura: Research Funding; Merck: Research Funding; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board, Research Funding; Kyowa: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Regeneron: Research Funding; Janssen: Research Funding; Bayer: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Cell Medica: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Astra Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Autolus: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board, Research Funding; Gilead/Kite: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Millenium: Research Funding; Agensys: Research Funding; Celgene: Research Funding; Forty Seven: Research Funding; Infinity: Research Funding. Marin Niebla:Amgen: Other: Medical education of Staff, Speakers Bureau; Roche: Consultancy, Other: Medical education of Staff, Speakers Bureau; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Other: Medical education of Staff, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Medical education of Staff, Speakers Bureau. Piris:Kura: Honoraria; Takeda: Honoraria; Janssen: Honoraria; Gilead: Honoraria. Curry:Kura Oncology: Employment, Equity Ownership. Gualberto:Kura Oncology: Employment, Equity Ownership.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3328-3328 ◽  
Author(s):  
Lorenz Selberg ◽  
Peter Stadtherr ◽  
Sascha Dietrich ◽  
Thomas Luft ◽  
Andrea Bondong ◽  
...  

Although alloHCT is an accepted salvage treatment in defined settings of poor-risk NHL, its potential benefit in these indications remains controversial because virtually all published studies are uncontrolled and restricted to patients who were actually able to undergo transplantation. Here, we aimed at assessing the impact of alloHCT by measuring its outcome from the time of donor search indication rather than from the time of transplant, thereby taking into account those patients who fail to proceed to allografting for any reason. Study design and patients : In a single centre retrospective analysis, course and outcome of all patients with diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) mantle cell lymphoma (MCL) and peripheral T-cell lymphoma (PTCL) who were considered as having an alloHCT indication according to accepted guidelines between 2004 and 2018 were recorded. Primary endpoint was overall survival (OS) from start of donor search. A key secondary endpoint was comparison of OS from the 3-month landmark by donor availability. Accepted donors were matched related donors (MRD), 10/10 matched unrelated donors (MUD), 9/10 compatible unrelated donors (MMUD), and mismatched related donors (MMRD), with haplo donors being used at our institution only since 2014. Results : Altogether a donor search was initiated in 187 patients (DLBCL 32%, FL 17%, MCL 23%, PTCL 28%). Median age was 54 (19-69) years with 74% being male. Within a median time from diagnosis to search initiation of 1.1 (0.1-19) years, a median of 4 (1-9) treatment lines had been administered, including an autoHCT in 50%. 69% of the patients had active disease at the time of search initiation. Only 2 patients underwent donor search in 1st remission (for Richter transformation and hepatosplenic T cell lymphoma, respectively). With a median follow-up of 6.2 (0.6-15.9) years, OS at 5 years after search initiation for DLBCL, FL, MCL, and PTCL was 25%, 44%, 52%, and 50%, respectively (Fig 1). 171 patients (91%) were alive at the 3-month landmark. For these, an MRD (20%), MUD (44%), MMUD (25%), or MMRD (7%) could be identified in 96% of the cases. AlloHCT was performed in 72% of all 187 patients, and in 79% of the patients alive at the 3-month landmark, with a significantly lower rate in DLBCL (69%) compared to the other entities. In patients who were actually transplanted, 5-year OS from landmark for DLBCL, FL, MCL and PTCL was 32%, 63%, 62%, and 62%, respectively, whereas only 5 of the 36 patients (14%) alive at the 3-month landmark not undergoing alloHCT for any reason survived long term. Due to the low rate of unsuccessful searches, donor vs no-donor landmark survival analyses were not possible. Conclusions: Despite donor search now being successful in virtually all cases, 20-30% of those patients intended for alloHCT for NHL will never proceed to transplant. However, long-term OS by ITT does not seem substantially worse than alloHCT outcome observed in registry studies restricted to patients actually transplanted, with DLBCL appearing inferior to the other 3 entities. Patients surviving the 3-month landmark but not undergoing alloHCT for any reason have a poor outlook. These results may serve as benchmark for novel therapeutic options entering the NHL treatment landscape. Disclosures Luft: Neovii: Research Funding; JAZZ: Research Funding. Schmitt:MSD: Membership on an entity's Board of Directors or advisory committees, Other: Sponsoring of Symposia; Therakos Mallinckrodt: Other: Financial Support. Dreger:Neovii, Riemser: Research Funding; MSD: Membership on an entity's Board of Directors or advisory committees, Other: Sponsoring of Symposia; AbbVie, Gilead, Novartis, Riemser, Roche: Speakers Bureau; AbbVie, AstraZeneca, Gilead, Janssen, Novartis, Riemser, Roche: Consultancy.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1617-1617 ◽  
Author(s):  
Jehan Dupuis ◽  
Rene-Olivier Casasnovas ◽  
Herve Ghesquieres ◽  
Franck Morschhauser ◽  
Herve Tilly ◽  
...  

Abstract Abstract 1617 Background: Romidepsin is a selective class 1 histone deacetylase inhibitor approved by the FDA for patients with cutaneous T-cell lymphoma and PTCL who have received at least 1 prior therapy. In recurrent/refractory PTCL, it has been evaluated as a single agent in 2 phase II studies with overall response rates of 25–38% (Piekarz, Blood 2011;117:5827; Coiffier, J Clin Oncol 2012;30:631). Toxicity was mainly hematologic and digestive. The aim of the present study was to evaluate the safety, tolerability and efficacy of different doses of romidepsin in association with CHOP in patients with previously untreated PTCL. Methods: Patients with biopsy-proven PTCL were planned to receive 8 cycles of CHOP (cyclophosphamide 750 mg/m2 day 1, doxorubicin 50 mg/m2 day 1, vincristine 1,4 mg/m2 day 1, prednisone 40 mg/m2 days 1 – 5) in association with varying doses of romidepsin. Based on pharmacokinetic data and results of previous phase II studies, the starting dose of 10 mg/m2 on days 1 & 8 was chosen. The dose-variation scheme follows a traditional “3+3” design. Dose-limiting toxicity (DLT) were considered during the first 2 cycles. Results: Eighteen patients (11 male, 7 female, aged 31 to 78) have been included and are analyzable for toxicity during the first two cycles. Diagnoses were: PTCL, not otherwise specified (n=10), angioimmunoblastic TCL (n=4), other PTCL (n=4). ECOG performance status was good (0–1) in all but one patient; 17/18 had stage III-IV disease; LDH levels were elevated in 11/18. The age-adjusted IPI score was 0 (n=1), 1 (n=14), 2 (n=3). Significant, albeit tolerable haematological toxicity having been observed in the first two cohorts, the definition of DLT was modified during the course of the study. The study diagram is shown in the figure. Accrual of the phase Ib part of the study is now completed and the phase II part is ongoing with a dose of 12 mg/m2 D1&8. Serious adverse events of interest included: One episode of acute pulmonary edema after course 1 in 1 patient, acute coronary syndrome (n=1), deep venous thrombosis (n=1) and cardiac arrhythmia (n=1). Among 14 evaluable patients, 3 progressed during treatment or shortly after end of treatment; and 11 responded (partial response 3/14, complete response 8/14) for an overall response rate of 78%. The 4 other patients have not yet reached the 8 cycles. Conclusion: Romidepsin can be combined with CHOP at the price of foreseeable hematological toxicity. Some cardiovascular events have been observed but the relationship with romidepsin is questionable. The dose of 12 mg/m2 on days 1& 8 is currently evaluated in the phase 2 part of the study. Response rates seem promising, but longer follow-up is needed. Updated results will be presented at the meeting. Disclosures: Ribrag: Servier: Membership on an entity's Board of Directors or advisory committees, Research Funding; astrazeneca: Membership on an entity's Board of Directors or advisory committees; takeda: Membership on an entity's Board of Directors or advisory committees; bayer: Research Funding; sanofi: Research Funding. Coiffier:Celgene: Consultancy.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5536-5536 ◽  
Author(s):  
Emma Nolan ◽  
Arwen Stikvoort ◽  
Mark Gurney ◽  
Nutsa Burduli ◽  
Lucy Kirkham-McCarthy ◽  
...  

Introduction: Chimeric Antigen Receptor (CAR) based cellular-immunotherapies have demonstrated significant clinical efficacy in haematological malignancies. However, the progress of cellular-immunotherapy for the treatment of Acute Myeloid Leukaemia (AML) has failed to gain momentum due to the lack of targetable tumour specific antigens. CD38 is a transmembrane glycoprotein expressed in lymphoid and myeloid cells with high expression in plasma B-cells, and is a well validated target for anti-CD38 therapy in Myeloma. A recent study has furthermore shown that a proportion of AML patients express CD38 on their leukemic blasts. TNF-related apoptosis-inducing ligand (TRAIL) receptor DR4 is another targetable antigen which has been shown to be expressed in 70% of AML patients. In this study, we investigate the therapeutic efficacy of "affinity-optimized" variant(s) of CD38 CAR and membrane bound TRAIL on NK-cell based platforms which can target AML blasts with high expression of CD38 (CD38high AML). The CAR variant is a CAR which binds with lower affinity to CD38 expressed on healthy immune cells such as CD38positive NK cells, while targeting CD38high AML. The membrane bound TRAIL variant (TRAIL4c9) is a mutant which binds with higher affinity to TRAIL-DR4 on AML cells, whilst avoiding binding to decoy receptors. We hypothesize that genetically modifying NK cells to express "affinity optimized" CD38 CARand/or TRAIL4c9 can effectively eliminate CD38high AML cells. Methods: AML cell lines THP-1, U937, and KG1a were immunophenotyped for CD38 and TRAIL-DR4 expression. Retrovirally transduced CD38 CAR-KHYG1 NK cells were used as immune effector cells and were co-cultured with AML cell lines in cytotoxicity assays. CD38low AML cell line KG1a was pre-treated with 10nM all-trans-retinoic acid (ATRA) to upregulate CD38 expression and were subsequently co-cultured with CD38 CAR-KHYG1 in cytotoxicity assays. CD38 CAR-KHYG1 was also co-cultured with n=4 patient derived AML cells in cytotoxicity assays. Using Maxcyte GT electroporation system primary donor derived IL-2 activated NK cells were either mock electroporated, or electroporated with TRAIL4c9 m-RNA orCD38 CAR m-RNA and subsequently co-cultured with THP-1 or ATRA pre-treated KG1a in a cytotoxicity assay. Expression of pro-apoptotic, anti-apoptotic and ligands for checkpoint inhibitory receptors was analysed by immunoblotting or flowcytometry. Results: Based on immunophenotyping, we classified AML cell lines as CD38high (THP-1), CD38moderate (U937) and CD38low (KG1a). CD38 CAR-KHYG1 was significantly more cytotoxic than MOCK KHYG1 against CD38high THP-1, at E:T ratios of 2.5:1, 5:1 and 10:1. CD38 CAR-KHYG1 were also more cytotoxic than MOCK KHYG1 against CD38moderate U937 at multiple E:T ratios; albeit the increase in cytotoxicity was at a much lower level in comparison to THP-1 (Fig 1a). Pre-treatment of CD38low KG1a cells with 10nM ATRA upregulated the cell surface expression of CD38, which were subsequently eliminated by CD38 CAR KHYG1 at E:T ratios of 2.5:1, 5:1 and 10:1. KG1a was intrinsically resistant to NK cells as compared to THP-1 and U937 (Fig 1b). This could partly be explained by the high intracellular expression of Bcl-xL, and higher cell surface expression of Nectin-1 and Sialic acid which are the ligands for checkpoint inhibitory receptors CD96 and Siglec-7/9 respectively on NK cell (Fig 1c). CD38 CAR-KHYG1 mounted a potent cytotoxic response against primary CD45intermediate AML blasts (n=4 patients) at multiple E:T ratios, and the extent of CAR induced cytotoxicity correlated with the cell surface CD38 expression on the primary AML blasts (R2=0.87) (Fig 1d,e). TRAIL4c9 or CD38 CAR m-RNA electroporated primary donor-derived NK cells were also potent in eliminating THP-1 and ATRA pre-treated KG1a at multiple E:T ratios (Fig 1f). This demonstrates the potential of therapeutically treating AML patients, with high CD38 expression, with a combination of NK cells expressing "affinity-optimized" CD38 CAR and membrane bound TRAIL variant. Conclusion: The study demonstrates the therapeutic potential of an "affinity-optimized" CD38 CAR NK cell-based therapy, which can potentially be combined with membrane bound TRAIL expressing NK cells to target CD38high AML. In patients with CD38low expressing AML blasts, patients could be pre-treated with ATRA followed by the combination therapy of CD38 CAR and TRAIL expressing NK cells. Disclosures Stikvoort: Onkimmune Ltd., Ireland: Research Funding. Kirkham-McCarthy:Onkimmune Ltd., Ireland: Research Funding. Van De Donk:Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees; AMGEN: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. Mutis:Celgene: Research Funding; Janssen Pharmaceuticals: Research Funding; Amgen: Research Funding; BMS: Research Funding; Novartis: Research Funding; Aduro: Research Funding; Onkimmune: Research Funding. Sarkar:Onkimmune: Research Funding. O'Dwyer:Onkimmune: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; GlycoMimetics Inc: Research Funding; AbbVie: Consultancy; BMS: Research Funding.


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