scholarly journals CD33 Targeting Primary CAR-NK Cells Generated By CRISPR Mediated Gene Insertion Show Enhanced Anti-AML Activity

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 3-3 ◽  
Author(s):  
Meisam Naeimi Kararoudi ◽  
Shibi Likhite ◽  
Ezgi Elmas ◽  
Maura Schwartz ◽  
Kinnari Sorathia ◽  
...  

Human peripheral blood natural killer (NK) cells have intense antitumor activity and have been used successfully in several clinical trials. Modifying NK cells with a chimeric antigen receptor (CAR) can improve their targeting and increase specificity. Recently, we described an efficient method for gene targeting in NK cells using Cas9/ribonucleoprotein complexes (PMID: 29985369 and 32603414). Here we combined this approach with single-stranded (ss) or self-complementary (sc) Adeno-associated virus (AAV)-mediated gene delivery for gene insertion into a safe-harbor locus using a wide variety of homology arms for homology repair (HR) and non-homologous directed CRISPR-assisted insertion tagging (CRISPaint) approaches. We demonstrated that expansion of NK cells on feeder cells (CSTX002) expressing membrane-bound IL21 increases expression of HDR-related genes and provides optimum biological condition for targeted gene insertion. For proof-of-concept, we successfully generated stable mCherry-expressing primary NK cells (up to 89% mCherry+) and determined that sc vectors with 300bp homology arms were optimal. Then, we generated CD33-targeting CAR NK cells with differing transmembrane and signaling domains (CD4/4-1BB+CD3ζ and NKG2D/2B4+CD3ζ), which continued to show robust expansion on CSTX002 and stably maintained their CAR expression. This resulted in CAR-NK-cells of high number and purity (mean 68% CAR+) that demonstrated enhanced antileukemic activity against acute myeloid leukemia (AML) cell lines. This efficient method for site-directed insertion of genetic materials into primary NK cells has broad potential for fundamental discovery and therapeutic applications. Keywords: CRISPR, NK, Cas9/RNP, AAV6, CRISPaint, HR, CD33CAR-NK Figure Disclosures Naeimi Kararoudi: Kiadis Pharma Netherlans B.V: Patents & Royalties. Lee:Kiadis Pharma Netherlands B.V: Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.

2021 ◽  
Author(s):  
Meisam Naeimi Kararoudi ◽  
Shibi Likhite ◽  
Ezgi Elmas ◽  
Kenta Yamamoto ◽  
Maura Schwartz ◽  
...  

Human peripheral blood natural killer (NK) cells have intense antitumor activity and have been used successfully in several clinical trials. Modifying NK cells with a chimeric antigen receptor (CAR) can improve their targeting and increase specificity. Recently, we described an efficient method for gene targeting in NK cells using Cas9/ribonucleoprotein (RNP) complexes. Here we combined this approach with single stranded (ss) or self-complementary (sc) Adeno-associated virus (AAV)-mediated gene delivery for gene insertion into a safe-harbor locus using a wide variety of homology arms for homology repair (HR) and non-homologous directed CRISPR-assisted insertion tagging (CRISPaint) approaches. For proof-of-concept, we generated mCherry-expressing primary NK cells and determined that sc vectors with 300bp homology 30 arms had optimal transduction efficiency. Then, we generated CD33-targeting CAR NK cells with differing transmembrane and signaling domains (CD4/4-1BB+CD3ζ and NKG2D/2B4+CD3ζ) and expanded them on CSTX002 feeder cells. Expansion kinetics were unaltered and the expanded NK cells maintained high CAR expression (mean 68% CAR+). The CD33-CAR-NK cells showed increased activation markers and enhanced antileukemic activity with improved killing kinetics against CD33-positive acute myeloid leukemia (AML) cell lines and primary samples. Using targeted sequencing we demonstrated the accuracy of CAR gene insertion in human primary NK cells genome. Site-directed insertion using RNP and scAAV6 is an efficient method for stable genetic transfer into primary NK cells that has broad potential for fundamental discovery and therapeutic applications.


2019 ◽  
Author(s):  
Meisam Naeimi Kararoudi ◽  
Shibi Likhite ◽  
Ezgi Elmas ◽  
Maura Schwartz ◽  
Kathrin Meyer ◽  
...  

AbstractHuman peripheral blood natural killer (NK) cells have strong antitumor activity and have been used successfully in several clinical trials. Modifying NK cells with a chimeric antigen receptor (CAR) can improve their targeting and increase specificity. However, genetic modification of NK cells has been challenging due to the high expression of innate sensing mechanisms for viral nucleic acids. Recently, we described an efficient vector-free method using Cas9/ribonucleoprotein complexes for gene deletion in NK cells. Here, we combined this approach with single-stranded (ss) or self-complementary (sc) Adeno-associated virus (AAV)-mediated gene delivery for gene insertion into a user-defined locus using homology repair (HR) and non-homologous directed CRISPR-assisted insertion tagging (CRISPaint) approaches. Using these approaches, we identified scAAV6 as the superior serotype for successful generation of stable mCherry-expressing primary NK cells (up to 89%). To maximize transgene packaging in HR-directed gene insertion, we identified minimum optimal homology arm lengths of 300bp for the flanking region of the Cas9-targeting site. Lastly, we demonstrate that mCherry positive NK cells can be expanded to large numbers using feeder cells expressing membrane-bound IL-21. This efficient method for site-directed insertion of genetic material into NK cells has broad potential for basic discovery and therapeutic applications for primary NK cells.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2345-2345
Author(s):  
Andrew F. Berdel ◽  
Christoph Rollig ◽  
Martin Wermke ◽  
Linus Angenendt ◽  
Leo Ruhnke ◽  
...  

Abstract Introduction Natural killer (NK) cells are key effectors in cancer immunosurveillance and posttransplant immunity, but shortage of environmental growth factors and deficient recognition of malignant cells may limit their anticancer efficacy. We hypothesized that the antibody-mediated anchoring of interleukin-2 (IL-2) to the leukemia-modified extracellular matrix (ECM) would increase NK cell abundance and activity to potentiate antibody-dependent cellular cytotoxicity (ADCC) against acute myeloid leukemia (AML) blasts. In this novel-novel combination dose-escalation phase 1 trial, we enrolled patients with AML relapse after allogeneic hematopoietic stem cell transplantation (HSCT) to evaluate the safety, pharmacokinetics, pharmacodynamics, and preliminary activity of F16IL2, an antibody-cytokine fusion protein composed of the human antibody fragment scFv(F16) in diabody format and two molecules of human IL-2, in combination with the Fc-optimized, ADCC-mediating anti-CD33 monoclonal antibody BI 836858. F16 specifically targets the A1 domain of the ECM protein tenascin C (TnC), which is spliced into the TnC molecule during active angiogenesis and tissue remodeling while it is virtually absent in normal tissues. Methods F16IL2 (10 - 20 Mio IU IV) was administered on days 1, 8, 15 and 22 of 28-day cycles, followed by administration of BI 836858 (10 - 40 mg IV) two days after each F16IL2 infusion. Dose escalation was performed over 4 dose levels (DL). Cohort 1 (10 Mio IU F16IL2 and 10 mg BI 836858, n = 5), cohort 2 (10 Mio IU F16IL2 and 20 mg BI 836858, n = 3), cohort 3 (20 Mio IU F16IL2 and 20 mg BI 836858, n = 4), cohort 4 (20 Mio IU F16IL2 and 40 mg BI 836858, n = 3). Safety and tolerability, pharmacodynamics and -kinetics, clinical efficacy and immune effector cell dynamics were investigated. This trial was registered at EudraCT as #2015-004763-37. Results Between December 2016 and March 2020, 15 patients with a median age of 50 years (range, 20 - 68) were enrolled and treated across 4 dose levels. Six patients (40%) had received two or more prior HSCT. The most frequent drug-related AEs (F16IL2 or BI 836858 or combination) were pyrexia (n = 13, 87%), chills (n = 12, 80%) and infusion-related reactions (n = 9, 60%), consistent with the expected toxicity profile of cytokine-armed or naked mAbs. These events were generally manageable, transient and of grade ≤ 2. One dose-limiting toxicity occurred at each of DL 3 (pulmonary edema) and 4 (acute GVHD). No patient died within the first 30 days of treatment initiation. Whereas no formal maximum tolerated dose (MTD) was reached, the maximum tested dose of 20 Mio IU F16IL2 and 40 mg BI 836858 was considered the recommended dose (RD). Three objective responses (1 CR, 1 CRi, 1 PR in extramedullary AML) were observed among 7 patients treated at the two higher DL, whereas no responses occurred at the two starting DL. Median OS among all 15 patients was 4.8 months (1.5 - 12.9), with a 6- and 12-month OS of 40% and 27%, respectively. Among those 7 patients whose AML was at least temporarily controlled with study treatment (CR/CRi, PR, SD), 12-month OS was 67% vs. 0% in non-responders. Combination therapy stimulated the expansion and activation of NK cells in bone marrow and peripheral blood. Conclusions To the best of our knowledge, this is the first study demonstrating that the strategy of potentiating ADCC with tumor-targeted immunocytokines is feasible in humans. In the difficult-to-treat situation of posttransplant AML relapse, responses were observed at higher DL, even in patients with extramedullary disease. The antibody-mediated targeted delivery of IL-2 to the ECM combined with anti-CD33 immunotherapy represents an innovative experimental approach associated with acceptable safety and encouraging biologic and clinical activity in posttransplant AML relapse. Disclosures Wermke: Novartis, Roche, Pfizer, BMS: Consultancy, Honoraria, Research Funding. Hemmerle: Philogen S.p.A.: Current Employment. Schäfers: Philogen S.p.A.: Research Funding. Rossig: BMS and Celgene: Honoraria; Pfizer: Honoraria; Novartis: Honoraria; AdBoards by Amgen: Honoraria. Stelljes: Pfizer: Consultancy, Research Funding, Speakers Bureau; Kite/Gilead: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; MSD: Consultancy, Speakers Bureau; Celgene/BMS: Consultancy, Speakers Bureau; Medac: Speakers Bureau; Amgen: Consultancy, Speakers Bureau. Rueter: Boehringer Ingelheim Pharma GmbH & Co. KG: Current Employment. Neri: Philogen S.p.A.: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: Multiple patents on vascular targeting; ETH Zurich: Patents & Royalties: CD117xCD3 TEA. Berdel: Philogen S.p.A.: Consultancy, Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees. Schliemann: Roche: Consultancy; Philogen S.p.A.: Consultancy, Honoraria, Research Funding; Astellas: Consultancy; Pfizer: Consultancy; BMS: Consultancy, Other: travel grants; Boehringer-Ingelheim: Research Funding; Novartis: Consultancy; Jazz Pharmaceuticals: Consultancy, Research Funding; AstraZeneca: Consultancy; Abbvie: Consultancy, Other: travel grants.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 3-3
Author(s):  
Murali Janakiram ◽  
Ravi Vij ◽  
David S. Siegel ◽  
Ted Shih ◽  
Sara Weymer ◽  
...  

Background: Allogeneic natural killer (NK) cell therapies have been well-tolerated with documented anti-tumor activity in patients with relapsed/refractory (r/r) hematologic malignancies including acute myelogenous leukemia (AML) and multiple myeloma (MM) (Lupo et al. 2019). Allogeneic NK cell therapies may offer an improved safety profile characterized by the absence of cytokine release syndrome and neurologic toxicity compared with T-cell therapies (Liu et al. 2020). However, in comparison to T cells, NK cells have limited in vivo expansion and a short half-life, and the potential to generate deeper and more durable anti-tumor responses through multi-dose administration is limited by the inability to consistently manufacture and administer more than one dose of allogeneic NK cells. The monoclonal antibodies (mAbs) daratumumab and elotuzumab have demonstrated clinical benefit and are approved for the treatment of MM (Darzalex® USPI, Empliciti® USPI). However, durable responses and disease-free survival remain limited. Engagement of the Fc portion of the mAb with CD16 on NK cells, which promotes antibody-dependent cellular cytotoxicity (ADCC), is a major contributor to the efficacy of daratumumab and elotuzumab. It is hypothesized that more clinically meaningful outcomes may be achieved by combining therapeutic mAbs with allogeneic NK cells engineered to enhance ADCC. FT538 is an investigational, first-of-kind, multiplexed engineered NK cell therapy generated from a clonal master engineered induced pluripotent stem cell (iPSC) line, which can be used as a renewable source for the mass production of off-the-shelf NK cells for broad patient access. FT538 is engineered with three modalities for enhanced innate immunity: (1) high-affinity 158V, non-cleavable CD16 Fc receptor for augmented ADCC; (2) interleukin (IL)-15/IL-15 receptor fusion that promotes cytokine-autonomous persistence; and (3) CD38 knockout to mitigate NK cell fratricide by CD38-directed mAbs. In preclinical studies, FT538 combined with daratumumab against MM targets demonstrated avoidance of daratumumab-mediated fratricide and significantly enhanced ADCC in vitro in a serial stimulation cytotoxicity assay compared with peripheral blood NK cells, and the combination of FT538 with daratumumab led to highly effective tumor control compared with daratumumab alone in an in vivo MM xenograft model (Bjordahl et al. 2019). Study Design and Methods: This study is a multicenter, multi-dose, Phase I clinical trial of FT538 in patients with r/r AML or r/r MM. The primary objectives are to determine the recommended Phase II dose of FT538 as monotherapy in r/r AML and in combination with daratumumab or elotuzumab in r/r MM. Key secondary objectives include evaluation of FT538 safety and tolerability, anti-tumor activity, and pharmacokinetics (PK) as monotherapy in r/r AML and combined with mAbs in r/r MM. Exploratory objectives include characterization of FT538 pharmacodynamics as assessed by peripheral blood biomarkers, assessment of minimal residual disease, and characterization of the tumor microenvironment in pre- and post-treatment tumor biopsies. The dose-escalation part of the trial utilizes a 3+3 design to identify the maximum tolerated dose of up to three doses of FT538 on Days 1, 8, and 15 as a monotherapy in r/r AML (Regimen A) and in combination with daratumumab (Regimen B) or elotuzumab (Regimen C) in r/r MM. The dose-expansion part of the trial will further characterize the safety, efficacy, and PK of FT538 in all regimens. The trial will test up to five FT538 dose levels ranging from 50 million to 1.5 billion cells. Up to 105 patients will be enrolled. The mAbs in Regimens B and C will be administered based on dosing schedules per their respective prescribing information. Lympho-conditioning consisting of three consecutive days of fludarabine and cyclophosphamide will be administered prior to the first dose of FT538. Key inclusion criteria include r/r disease after standard approved therapies for r/r AML or r/r MM, as applicable, measurable disease for r/r MM, and adequate organ function. Key exclusion criteria include active central nervous system disease, need for systemic immunosuppressive therapy, and prior allograft organ transplant. This trial is expected to begin patient enrollment in 2020. Disclosures Janakiram: Takeda, Fate, Nektar: Research Funding. Siegel:Karyopharma: Consultancy, Honoraria; Takeda: Consultancy, Honoraria, Speakers Bureau; Merck: Consultancy, Honoraria, Speakers Bureau; Celulatiry: Consultancy; BMS: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau. Shih:Fate Therapeutics, Inc.: Current Employment, Current equity holder in publicly-traded company. Weymer:Fate Therapeutics, Inc.: Current Employment, Current equity holder in publicly-traded company. Valamehr:Fate Therapeutics, Inc: Current Employment, Current equity holder in publicly-traded company. Chu:Roche Holding AG: Current equity holder in publicly-traded company; Fate Therapeutics, Inc.: Current Employment, Current equity holder in publicly-traded company. Miller:Fate Therapeutics, Inc: Consultancy, Patents & Royalties, Research Funding; GT Biopharma: Consultancy, Patents & Royalties, Research Funding; Vycellix: Consultancy; Onkimmune: Honoraria, Membership on an entity's Board of Directors or advisory committees; Nektar: Honoraria, Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Cyclophosphamide and fludarabine will be used as lympho-conditioning therapy prior to FT538 administration.


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.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4809-4809
Author(s):  
Alexander G Allen ◽  
Rithu Pattali ◽  
Kaitlyn M Izzo ◽  
Jared A Getgano ◽  
Kevin M Wasko ◽  
...  

Abstract Current cell and gene therapy medicines for oncology have reshaped how cancer is treated. Specifically, chimeric antigen receptor (CAR)-T cells have demonstrated that cell therapy can achieve durable remissions in hematologic malignancies. However, CAR-T cell therapies have limited efficacy in solid tumors and are often associated with severe toxicity, highlighting the need for novel cell therapies that are safer and more efficacious. With their intrinsic killing capacity of tumor cells and few, if any, treatment related toxicities, natural killer (NK) cell therapies represent an attractive alternative therapy option to CAR-T cells. In addition, NK cells can be generated from allogeneic donors and given to patients off-the-shelf without causing graft versus host disease. Of the various sources of donor types to generate NK cells from, induced pluripotent stem cells (iPSCs) have the unique advantage of being a renewable source. A clone with any desired edits to enhance the effector function of NK cells can be derived, fully characterized, and expanded indefinitely, to generate large quantities of a naturally allogeneic medicine, therefore streamlining the manufacturing process and increasing scalability. Here, a bicistronic cargo encoding CD16 and a membrane-bound IL-15 (mbIL-15) was knocked into iPSCs at the GAPDH locus using an engineered and highly active AsCas12a. The promoter at the GAPDH locus drives robust constitutive expression of inserted cargos and avoids the promoter silencing that often occurs during differentiation with other strategies. CD16 and mbIL-15 were selected as Knock-Ins (KI) to specifically enhance NK cell therapy in two areas, namely NK cell deactivation caused by CD16 downregulation, and the reliance of co-administration of cytokines such as IL-15 or IL-2 for persistence. CD16 (FcRyIII) can bind the Fc portion of IgG antibodies triggering the lysis of targeted cells. This mechanism of cytotoxicity is known as antibody dependent cellular cytotoxicity (ADCC), and is an innate immune response largely mediated by NK cells through CD16. ADCC is severely impaired when surface CD16 is cleaved by a metalloprotease known as ADAM17. By having CD16 expressed from the GAPDH locus, there is consistent CD16 protein expression to replace what is shed. This hypothesis was demonstrated by performing flow cytometry before and after a cytotoxicity assay. WT cells showed a marked reduction in the surface level expression of CD16 compared to CD16 KI cells after tumor cell exposure. Using a lactate dehydrogenase (LDH) release assay as a measure of cytotoxicity, only the iNK cells expressing the CD16 construct showed statistically significant increases in cytotoxicity when trastuzumab was added. Furthermore, to better model a solid tumor, a 3D tumor spheroid killing assay was utilized where CD16 KI cells showed an increase in ADCC capacity. The benefit of increased effector function via CD16 KI cannot be fully realized without iNK cells persisting. IL-2 or IL-15 is needed for NK maintenance but the administration of either cytokine is associated with acute clinical toxicities. mbIL-15 allows NK cells to survive for a prolonged period without the support of homeostatic cytokines. An in vitro persistence assay was performed that demonstrated IL-15 KI cells showed an increase in persistence compared to WT cells. Specifically, during the three-week in vitro assay, WT cells became undetectable by Day 14 while IL-15 KI NK cells remained stable over time. In summary, to overcome two shortfalls of NK cell therapies, a bicistronic construct encoding CD16 and a mbIL-15 was knocked into the GAPDH locus of iPSCs. The strong GAPDH promoter drove constitutive expression of CD16 that mitigated CD16 shedding, enhanced ADCC of iNK cells, which can be used in combination with any ADCC enabling IgG1 and IgG3 antibodies, such as trastuzumab and rituximab, for tumor-specific targeting. In addition, mbIL-15 KI allowed iNK cells to persist without exogenous cytokine administration and thus can circumvent exogeneous cytokine-induced clinical toxicities. CD16 and mbIL-15 double KI iNKs, with enhanced ADCC and increased cytokine-independent persistence, can potentially be developed into a safe and efficacious therapy for the treatment of a variety of liquid and solid tumors with high unmet medical needs. Disclosures Allen: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Pattali: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Izzo: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Getgano: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Wasko: Editas Medicine: Current equity holder in publicly-traded company, Ended employment in the past 24 months. Blaha: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Zuris: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Zhang: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Shearman: Editas Medicine: Current Employment, Current equity holder in publicly-traded company. Chang: Editas Medicine: Current Employment, Current equity holder in publicly-traded company.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3868-3868
Author(s):  
Michael Dickinson ◽  
Nada Hamad ◽  
Christian E Bryant ◽  
Gautam Borthakur ◽  
Chitra Hosing ◽  
...  

Abstract Background: B-cell lineage cancers are a worldwide healthcare burden. Over 500,000 new cases of non-Hodgkin lymphoma (NHL) and 50,000 new cases of acute lymphoblastic leukemia (ALL) are diagnosed world-wide each year (seer.cancer.gov, Smith 2015, Solomon 2017). Despite progress in treatment, many patients diagnosed with this heterogeneous group of cancers still succumb to their disease. Recently approved autologous chimeric antigen receptor (CAR) T cells specific for CD19 have altered the treatment landscape for some patients with relapsed or refractory (R/R) B-cell malignancies, though significant toxicities associated with T-cell expansion and the necessity for bespoke manufacturing have limited their use. Natural killer (NK) cells, part of the innate immune system, efficiently recognize transformed cells and are particularly suited to address limitations of the approved CAR T products (Marcus 2014, Morvan 2016). Lacking a T-cell receptor and the consequent clonal expansion, non-engineered NK cells have been safely administered after lymphodepletion without side effects typically associated with T-cell therapies, such as severe cytokine release syndrome or neurotoxicity (Bachier 2020). Allogeneic NK cell-based therapies allow off-the-shelf use, obviating the necessity to wait for manufacture of autologous T-cell therapies. CD19-directed CAR NK cells have been administered safely, with promising preliminary efficacy (Liu 2020). NKX019 is a cryopreserved product, composed of expanded NK cells engineered to express a humanized CAR against CD19, fused to co-stimulatory (OX40) and signaling (CD3ζ) domains to enhance their intrinsic antitumor activity. NKX019 also expresses a membrane-bound interleukin-15 (IL-15) to serve as an autocrine growth factor and thereby increase NKX019 persistence, with an in vivo half-life of over up to 28 days without systemic IL-2 support. Preclinical characterization has shown that NKX019 cells are 10 times more effective at killing CD19+ target cells than non-engineered NK cells, resulting in greater suppression of xenograft tumor models (Morisot 2020). Further, NKX019, unlike CD19 CAR T cells, retained cytotoxicity even when CD19 antigen density was reduced >50x on target cells. Hence, clinical evaluation of NKX019 is being undertaken in this Phase 1 study in subjects with R/R NHL or ALL. Methods: This is a multicenter, open-label, Phase 1 study of NKX019 (Figure). The study will be conducted in 2 parts: Part 1 (dose finding) to determine the recommended Phase 2 dose (RP2D) of NKX019 separately in adult patients with CAR T naïve R/R NHL or B-ALL, utilizing a "3+3" enrollment schema. Part 2 (dose expansion) will further evaluate safety and tolerability, pharmacokinetics (PK), immunogenicity, pharmacodynamics (PDn), and antitumor activity of NKX019 using RP2D with separate expansion cohorts for patients with ALL as well as different subtypes of NHL, including a cohort of CAR T pretreated large B-cell lymphoma. NKX019 is being manufactured from NK cells obtained from healthy adult donors. The study evaluates two dose levels of NKX019: 3 × 10 8 and 1 × 10 9 viable CAR+ NK cells. NKX019 will be administered on Days 0, 7, and 14 of a 28-day cycle following standard fludarabine/cyclophosphamide lymphodepletion (Table). Up to 5 total cycles may be administered based on response and tolerability assessed at the end of each cycle. The primary endpoint is incidence of adverse events, dose-limiting toxicities, clinically significant laboratory abnormalities, and determination of the RP2D. Secondary endpoints include evaluation of standard cellular PK parameters, PDn, immunogenicity, and antitumor responses. Subjects will be assessed for efficacy using disease-specific criteria: Lugano classification with LYRIC refinement for pseudo-progression (NHL), 2018 International Workshop (IW) criteria (CLL), 6th IW criteria (Waldenström macroglobulinemia [WM]), and National Comprehensive Cancer Version 1.2020 (B-ALL) (Cheson 2006, Cheson 2014, Hallek 2018, Owen 2013, Brown 2020). Enrollment across multiple sites in the US and Australia is expected to start in the second half of 2021. Figure 1 Figure 1. Disclosures Dickinson: Celgene: Research Funding; Gilead Sciences: Consultancy, Honoraria, Speakers Bureau; MSD: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria; Bristol-Myers Squibb: Consultancy, Honoraria; Takeda: Research Funding; Amgen: Honoraria; Roche: Consultancy, Honoraria, Other: travel, accommodation, expenses, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau. Hamad: Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Bryant: Jansen, BMS/Celgene, Skyline Diagnostics: Consultancy; Amgen: Honoraria. Borthakur: Astex: Research Funding; University of Texas MD Anderson Cancer Center: Current Employment; Protagonist: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy; Ryvu: Research Funding; ArgenX: Membership on an entity's Board of Directors or advisory committees. Hosing: Nkarta Therapeutics: Membership on an entity's Board of Directors or advisory committees. Shook: Nkarta Therapeutics: Current Employment, Current equity holder in publicly-traded company. Tan: Nkarta Therapeutics: Current Employment, Current equity holder in publicly-traded company. Rajangam: Nkarta Therapeutics: Current Employment, Current equity holder in publicly-traded company. Liu: SITC: Honoraria; BMS; Karyopharm; Miltenyi: Research Funding; Agios; NGM Biopharmaceuticals; BeiGene: Consultancy. McSweeney: Kite-Gilead: Consultancy; Kite-Gilead, Autolus, Novartis: Research Funding; Kite-Gilead: Honoraria, Speakers Bureau. Hill: Novartis: Consultancy, Honoraria, Research Funding; Epizyme: Consultancy, Honoraria; AstraZenica: Consultancy, Honoraria; Beigene: Consultancy, Honoraria, Research Funding; Kite, a Gilead Company: Consultancy, Honoraria, Other: Travel Support, Research Funding; Pfizer: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria, Research Funding; Incyte/Morphysis: Consultancy, Honoraria, Research Funding; Gentenech: Consultancy, Honoraria, Research Funding; Celgene (BMS): Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4357-4357
Author(s):  
Arghya Ray ◽  
Ting DU ◽  
Nina N. Nupponen ◽  
Fredrik Lehmann ◽  
Jakob Lindberg ◽  
...  

Abstract Introduction Melphalan flufenamide (Melflufen; Oncopeptides AB) is a novel enzyme-activated analogue of melphalan that enables a more rapid and higher intracellular accumulation of melphalan in tumor cells than is achievable by direct exposure to equimolar doses of melphalan. Our preclinical study showed that melflufen is a more potent anti-myeloma (MM) agent than melphalan, overcomes drug-resistance, and induces synergistic anti-MM activity in combination with bortezomib, lenalidomide, or dexamethasone (Chauhan et al, Clinical Cancer Res 2013;19:3019). However, the effect of melflufen on the immunosuppressive and tumor-promoting MM-host bone marrow (BM) accessory cells such as immunologically dysfunctional plasmacytoid dendritic cells (pDCs; CD123/IL-3Rα) remains unclear. Here, we utilized our coculture models of pDCs, T-, and NK cells with autologous patient MM cells to examine whether a combination of melflufen and immune checkpoint inhibitor anti-PD-L1 Ab, or daratumumab (anti-CD38 Ab), restores anti-MM immunity. Methods MM patient BM and PB samples (N=10; obtained after informed consent), and cell lines were used for the study. Minimally cytotoxic concentration of melflufen (0.1 µM) was used to assess immune functions. CTL/NK activity assays MM CD8 + T- or NK-cells were cultured with autologous pDCs (1:10 pDC:T/NK ratio) with melflufen (0.1 μM) alone, and with anti-PD-L1 (5 μg/ml) or anti-CD38 (0.5 μg/ml) Abs for 3-5 days; cells were washed to remove the drugs, and then cultured for another 24h with pre-stained target MM cells (10:1 E/T ratio; T/NK:MM), followed by quantification of viable MM cells by flow. Results 1) Both MM tumor cells and pDCs showed higher PD-L1 and CD38 levels vs normal plasma cells; 2) Treatment of MM patient total BM mononuclear cells or purified MM cells with melflufen (0.1 µM) increased PD-L1 expression on MM cells (1.84-fold, treated vs untreated; p<0.05). Importantly, treatment of MM cells with melflufen and anti-PD-L1 Abs enhanced anti-MM cytotoxicity; 3) Combination of melflufen and anti-PD-L1 Ab triggers activation of CD3 + T cells, evidenced by an increase in CD69 expression on CD3 + T cells (1.15-fold, treated vs untreated, p<0.05); 4) Combination of melflufen and anti-PD-L1 Ab induced a more robust autologous MM-specific CD8 + cytotoxic T lymphocyte (CTL) activity than melflufen alone (% MM lysis: melflufen: 20%; melflufen plus anti-PD-L1 Ab: 60%; n=5; p=0.013); 5) Meflufen and anti-PD-L1 also triggered pDC-induced NK cell-mediated MM-specific cytolytic activity (p<0.05); and finally, 6) Low doses of melflufen and anti-CD38 Abs enhanced pDC-induced NK cell-mediated MM-specific cytolytic activity (%Viability: melflufen: 75%; melflufen + anti-CD38 Ab: 12.5%; n=4; p=0.001). Conclusions The combination of melflufen and anti-PD-L1 increases pDC-induced T- and NK cell-mediated cytolytic activities against MM. Moreover, combined melflufen and anti-CD38 Abs modestly enhance pDC-induced NK cell-mediated MM-specific cytolytic activity. Our preclinical data suggest targeting PD-L1 in combination with melflufen as well as support an ongoing clinical trial of melflufen with anti-CD38 Abs to enhance anti-MM immunity. Disclosures Nupponen: Oncopeptides AB: Consultancy. Lehmann: Oncopeptides AB: Current Employment. Lindberg: Oncopeptides: Current Employment, Current equity holder in publicly-traded company, Divested equity in a private or publicly-traded company in the past 24 months, Other: Travel, Accommodations, Expenses; Camurus: Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Affibody: Membership on an entity's Board of Directors or advisory committees. Gullbo: Oncopeptides AB: Consultancy. Richardson: Takeda: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; Janssen: Consultancy; Sanofi: Consultancy; Protocol Intelligence: Consultancy; Karyopharm: Consultancy, Research Funding; GlaxoSmithKline: Consultancy; Regeneron: Consultancy; AstraZeneca: Consultancy; Secura Bio: Consultancy; AbbVie: Consultancy; Oncopeptides: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding. Chauhan: C4 Therapeutics: Current equity holder in publicly-traded company; Oncopeptides: Consultancy; Stemline Therapeutics: Consultancy. Anderson: Janssen: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Sanofi-Aventis: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Millenium-Takeda: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Scientific Founder of Oncopep and C4 Therapeutics: Current equity holder in publicly-traded company, Current holder of individual stocks in a privately-held company; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Mana Therapeutics: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 11-12
Author(s):  
Stefan O. Ciurea ◽  
Jolie Schafer ◽  
Piyanuch Kongtim ◽  
Julianne Chen ◽  
Doris Soebbing ◽  
...  

Background: Allogeneic stem-cell transplantation (alloSCT) remains the only curative treatment for patients with advanced AML. However, only a minority of these patients achieve disease control prior to transplantation. Natural Killer (NK) cells have potent anti-leukemic activity but are functionally deficient in AML. Adoptive NK-cell therapy using high-doses of functionally active NK-cells could overcome these limitations. We previously developed an ex vivo NK-cell expansion method based on K562 feeder cells modified to express membrane bound IL-21 (mbIL-21) and 4-1BB ligand, (FC21), which resulted in high numbers of hyperfunctional FC21-NK cells with enhanced cytotoxicity and cytokine production. Here we report outcomes of a phase I clinical trial designed to assess the safety, feasibility and maximum tolerated dose (MTD) of haploidentical FC21-NK cells for patients with relapse/refractory (R/R) AML at MD Anderson Cancer Center. Methods: Eligible patients were ≥18 years, KPS ≥70 with good organ function. Patients with relapsed AML after alloSCT were eligible if they had no active GVHD and did not require immunosuppression. Haploidentical donors were selected based on KIR characteristics, when multiple donors were available. Donor NK cells were expanded over 3 weeks and cryopreserved. Three dose levels between 106-108 cells/kg were planned. Patients received cytoreductive chemotherapy with fludarabine 30 mg/m2/day and cytarabine 2 g/m2/day for 5 days (4 days for age >60) and G-CSF (subsequently eliminated). 3-7 days after chemotherapy, patients received FC21-NK cell infusions 3 times per week, up to 6 infusions. Results: As of 4/14/2020, 15 patients were screened, 12 of whom were eligible and received the FC21-NK cells. Median age was 60 years (range 25-70); 6 (50%) had adverse cytogenetics, 8 (66.7%) had adverse ELN genetic risk, 6 (50%) had primary induction failure, 2 (16.7%) had CNS disease and 4 (33.3%) had secondary AML. Median number of prior treatment regimens was 5 (range 2-8), median blast count at enrollment was 47% (range 7-88). Median time from diagnosis to enrollment and to first NK-cell infusion was 16.6 (range 2.5-98.1) and 17.2 (range 3.1-98.6) months, respectively. Donor-recipient NK-cell alloreactivity was seen in 5 patients (41.7%). Median number of NK-cell infusion was 6 (range 3-6); 8 (66.7%) and 4 (33.3%) patients received NK-cell dose of 1 X106 and 1 X107 cells/kg, respectively. MTD was not reached. Seven patients had ANC recovery post-NK cell infusion with cumulative incidence (CI) of ANC recovery to 500/mm3 at 60 days of 58.3%. Eight patients (66.7%) achieved complete remission (CR) (N=4, 33.3%) or CR with incomplete hematologic recovery (CRi) (N=4, 33.3%) at 30 days post-NK cell infusion. One patient with CR had negative minimal residual disease (MRD). Five patients (41.7%) proceeded to haploidentical alloSCT from the same donor and were transplanted in CR/CRi, all but one with persistent MRD. With a median follow-up of 13 months (range 4.1-42.7), median OS and DFS were 17.6 and 3.3 months, and 28 and 20 months for patients receiving alloSCT, respectively. Other outcomes including 2-year OS, DFS, relapse and TRM are shown in Figure 1 and Table 1. No infusion related toxicity or cytokine release syndrome was observed. Two patients were evaluable for FC21-NK cell persistence with haplotype-specific anti-HLA antibodies. FC21-NK cells were detected 5 and 6 weeks after the last FC21-NK cell infusion, respectively. A progressive decrease of the blast population with progressive expansion of the FC21-NK cell population after repeated NK-cell infusions was noted in samples collected from one pt (Figure 2). Persistence is also being evaluated by STR chimerism. Conclusions: Multiple infusions of FC21-NK cells yielded unprecedented outcomes with 66.7% of patients responding and approximately half proceeding to alloSCT in a heavily pre-treated, ultra-refractory, high-risk patient population. Responses were observed irrespective of dose. FC21-NK cell therapy was very well tolerated with no attributable AEs and were shown to persist for at least 5 weeks after infusion. These encouraging results warrant further clinical evaluation of FC21-NK cells in R/R AML patients. Disclosures Ciurea: Kiadis Pharma: Current equity holder in publicly-traded company, Research Funding. Schafer:Kiadis Pharma: Current Employment. Shpall:Zelluna: Membership on an entity's Board of Directors or advisory committees; Adaptimmune: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Magenta: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Takeda: Other: Licensing Agreement. Konopleva:Calithera: Research Funding; Eli Lilly: Research Funding; Kisoji: Consultancy; Reata Pharmaceutical Inc.;: Patents & Royalties: patents and royalties with patent US 7,795,305 B2 on CDDO-compounds and combination therapies, licensed to Reata Pharmaceutical; Forty-Seven: Consultancy, Research Funding; Sanofi: Research Funding; AstraZeneca: Research Funding; Agios: Research Funding; Ablynx: Research Funding; AbbVie: Consultancy, Research Funding; Ascentage: Research Funding; Rafael Pharmaceutical: Research Funding; Cellectis: Research Funding; F. Hoffmann La-Roche: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Amgen: Consultancy; Stemline Therapeutics: Consultancy, Research Funding. Lee:Kiadis Pharma Netherlands B.V: Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Champlin:Actinium: Consultancy; Johnson and Johnson: Consultancy; Omeros: Consultancy; DKMS America: Membership on an entity's Board of Directors or advisory committees; Cytonus: Consultancy; Genzyme: Speakers Bureau; Takeda: Patents & Royalties.


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