scholarly journals Bispecific Vγ9Vδ2-T and Type 1 NKT Cell Engager Lava-051 As First-in-Class Clinical Candidate to Target CD1d Expressing CLL, MM and AML

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2266-2266
Author(s):  
Roeland Lameris ◽  
Jurjen M Ruben ◽  
Iris de Weerdt ◽  
Rob Roovers ◽  
Niels W.C.J. van de Donk ◽  
...  

Abstract Background. Bispecific antibodies that target tumors by engaging innate-like T cell subsets with inherent antitumor activity, such as Vγ9Vδ2-T and type 1 natural killer T (NKT) cells, may combine high therapeutic efficacy with limited off-tumor toxicity. Type 1 NKT cells respond to self and foreign (glyco)lipid antigens presented in the context of the MHC class I like molecule CD1d which is expressed on various malignancies. Vγ9Vδ2-T cells respond to intracellular accumulation of phosphoantigens in cancer cells by sensing conformational alterations in the butyrophilin (BTN) 2A1-3A1 complex. CD1d is expressed by the majority of patients with CLL and MM, while expression in AML is most pronounced on (myelo)monocytic subtypes. Methods. LAVA-051 is a 27kD humanized bispecific single domain antibody (bsVHH) that directly engages CD1d and the Vδ2-TCR chain of Vγ9Vδ2-T cells. The anti-CD1d VHH specifically stabilizes the interaction between CD1d and the type 1 NKT cell TCR and thereby triggers strong activation of type 1 NKT cells (Nature Cancer 2020;1:1054-1065). Vγ9Vδ2-T and type 1 NKT effector cell activation, proliferation, cytokine production and target cell lysis were assessed in in vitro, ex vivo, and in vivo studies. Due to lack of cross reactivity of LAVA-051 with non-human primate (NHP) CD1d and Vγ9Vδ2-T cells, a cross-reactive surrogate bispecific engager was generated to assess tolerability, pharmacokinetic (PK) and pharmacodynamic (PD) parameters. Results. The CD1d-Vδ2 bsVHH LAVA-051 triggers activation of both Vγ9Vδ2-T and type 1 NKT cells (EC 50 4 pM for Vγ9Vδ2-T and 366 pM for type 1 NKT; induction of > 80% degranulation in 4h assays) and mediates potent killing of CD1d expressing tumor cells by engagement of Vγ9Vδ2-T and/or type 1 NKT cells (EC 50 1 pM for Vγ9Vδ2-T and 216 pM for type 1 NKT; > 85% target cell lysis in 16h assays at a low 1:2 E:T ratio). Further, LAVA-051 triggered pro-inflammatory cytokine production, proliferation of Vγ9Vδ2-T and type 1 NKT cells, and exerted substantial antitumor activity against patient AML, CLL and MM cells that express CD1d and improved survival in in vivo T-ALL, AML and MM mouse models. Multiple dose studies in NHP (7 daily doses up to 1 mg/kg iv) showed clear Vγ9Vδ2-T cell engagement and some cytokine release after the first administration, but no clinical, laboratory, or histopathological toxicity. Reflecting the low molecular size of this bispecific engager, PK studies revealed a short plasma half-life which was however compensated for by prolonged (up to 5 days) binding of the engager to peripheral blood Vγ9Vδ2-T cells allowing intermittent dosing. Conclusions. In this study, we demonstrate that the CD1d-Vδ2 bsVHH LAVA-051 triggers activation of both type 1 NKT and Vγ9Vδ2-T cells, which translates directly into antitumor activity. Based on the expression of CD1d in CLL, MM, and AML, the strong preclinical activity of LAVA-051 against CD1d-expresssing tumors, and the favorable tolerability profile of the surrogate engager in NHP, LAVA-051 is currently evaluated in a first-in-human clinical Phase 1/2a study in patients with CD1d-expressing CLL, MM, or AML refractory to prior therapy (NCT04887259). Disclosures Lameris: Lava Therapeutics: Honoraria, Patents & Royalties, Research Funding. Ruben: Lava Therapeutics: Current Employment, Honoraria, Research Funding. Weerdt: LAVA Therapeutics: Research Funding. Roovers: LAVA Therapeutics: Current Employment, Current equity holder in publicly-traded company. van de Donk: Janssen Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Adaptive Biotechnologies: 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; Takeda: 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, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; Servier: Membership on an entity's Board of Directors or advisory committees; Cellectis: Research Funding. Broyl: Amgen: Honoraria; Bristol-Meyer Squibb: Honoraria; Celgene: Honoraria; Janssen Pharmaceuticals: Honoraria; Sanofi: Honoraria. Kater: Abbvie: Honoraria, Other: Ad Board, Research Funding; Janssen, AstraZeneca: Other: Ad Board, steering committee, Research Funding; Genmab, LAVA: Other: Ad Board, Steering Committee; BMS, Roche/Genentech: Other: Ad Board, , Research Funding. Riedl: LAVA THerapeutics: Current Employment, Current equity holder in publicly-traded company; Genmab BV: Current equity holder in publicly-traded company. Iglesias: LAVA therapeutics: Current Employment. Winograd: LAVA therapeutics: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees; Celgene: Ended employment in the past 24 months; BMS: Current equity holder in publicly-traded company. Adang: LAVA therapeutics: Current Employment, Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees. de Gruijl: LAVA therapeutics: Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; DCPrime: Membership on an entity's Board of Directors or advisory committees; Macrophage Pharma: Membership on an entity's Board of Directors or advisory committees, Research Funding; Partner Tx: Membership on an entity's Board of Directors or advisory committees; Idera Pharmaceuticals: Research Funding; ORCA Therapeutics: Patents & Royalties. Parren: Lava Therapeutics: Current Employment, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Sparring Bioconsult BV: Membership on an entity's Board of Directors or advisory committees; Genmab: Patents & Royalties; Roche: Consultancy. Vliet: Lava Therapeutics: Current Employment, Current equity holder in publicly-traded company, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Glycostem: Research Funding.

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 471-471
Author(s):  
Swati Naik ◽  
Spyridoula Vasileiou ◽  
Ifigeneia Tzannou ◽  
Manik Kuvalekar ◽  
Ayumi Watanabe ◽  
...  

Abstract Background: Hematopoietic stem cell transplant (HSCT) is a curative option for patients with high-risk Acute Lymphoblastic Leukemia (HR-ALL), but relapse remains a major cause of treatment failure. Strategies to enhance the graft-versus-leukemia (GVL) effect have been employed to prevent relapse, including modulating immune suppression post-HSCT to hasten immune reconstitution or with the use of donor lymphocyte infusions (DLIs). However, DLIs carry a significant risk of graft-versus-host disease (GVHD) due to the concurrent transfer of alloreactive T cells. To enhance the GVL effect while minimizing GVHD, we developed a protocol for the generation of ex vivo expanded, donor-derived T-cell lines targeting PRAME, WT1 and Survivin - tumor associated antigens that are frequently expressed in both B- and T-cell ALL. These multi-antigen-targeted T cells (multiTAAs) were adoptively transferred to pediatric and adult patients with HR-ALL who had undergone an allogeneic HSCT. Methods: Donor-derived multiTAA-specific T cells were generated by co-culturing PBMCs with autologous DCs loaded with pepmixes (15 mer peptides overlapping by 11 amino acids) spanning all 3 target antigens in the presence of a Th1-polarizing/pro-proliferative cytokine cocktail. Following 2-4 rounds of stimulation these multiTAA-specific T cells were infused to patients with ALL who had undergone an HSCT but remained at a high risk for disease relapse. Results: We have generated 15 clinical grade multiTAA-specific T cell lines comprising CD3+ T cells (mean 95.1±1.9%) with a mixture of CD4+ (mean 22.8±6.3%) and CD8+ (mean 52.5±5.3%) cells, which expressed central [CD45RO+/CD62L+: 13.5±2.8%] and effector memory markers [CD45RO+/CD62L-: 56.4±3.8%]. The expanded lines recognized the targeted antigens PRAME (range 0-370 SFC/2x10 5), WT1 (0-363 SFC/2x10 5), and Survivin (0-65 SFC/2x10 5) in an IFNg ELIspot. None of the lines reacted against non-malignant patient-derived cells (3.7±0.8% specific lysis; E: T 20:1) - a study release criterion indicating lack of alloreactivity. We have infused 11 HR-ALL patients (8 pediatric and 3 adult) with donor-derived multiTAA-specific T cells to prevent disease relapse (Table 1). Patients were administered with up to 4 infusions of cells at 3 escalating dose levels, ranging from 0.5 - 2x10 7 cells/m 2. Infusions were well tolerated with no dose-limiting toxicity, GVHD, cytokine release syndrome or other adverse events. Three patients were not evaluable per study criteria as they received >0.5mg/kg of steroids (2 patients received stress doses for septic shock and 1 for elevated liver enzymes presumed to be GVHD that was later ruled out) within 4 weeks of infusion and were replaced. Six of the 8 remaining patients infused remain in CR on long-term follow up at a median of 46.5 months post-infusion (range 9-51 months). In patients who remained in long term CR we detected an expansion of tumor-reactive T cells in their peripheral blood post-infusion against both targeted (WT1, Survivin, PRAME) and non-targeted antigens (SSX2, MAGE-A4, -A1, -A2B, -C1, MART1, AFP and NYESO1) reflecting epitope and antigen spreading, which correlated temporally (within 4 weeks) with multiTAA infusions. By contrast in the two patients who relapsed we saw no evidence of in vivo T cell amplification within the first 4 weeks after infusion. Conclusion: The preparation and infusion of donor-derived multiTAA-specific T cells to patients with B- and T-ALL post allogeneic HSCT is feasible, safe and as evidenced by in vivo tumor-directed T cell expansion and antigen spreading in patients, may contribute to disease control. This strategy may present a promising addition to current immunotherapeutic approaches for prophylaxis for leukemic relapse in HSCT recipients. Figure 1 Figure 1. Disclosures Vasileiou: Allovir: Consultancy. Tzannou: Gileas: Honoraria; Allovir: Current equity holder in publicly-traded company. Kuvalekar: Allovir: Consultancy. Watanabe: Allovir: Consultancy. Grilley: QB Regulatory Consulting: Other: Ownership, project management support, Research Funding; Marker: Consultancy, Other: Regulatory and project management support; Allovir: Current equity holder in publicly-traded company, Other: Leadership. Hill: Incyte: Membership on an entity's Board of Directors or advisory committees. Omer: Allovir: Research Funding. Gottschalk: Tessa Therapeutics: Consultancy; Immatics: Membership on an entity's Board of Directors or advisory committees; Other: Other: patents and patent applications in the field of cancer cell and gene therapy ; Tidal: Consultancy; Novartis: Consultancy; Catamaran Bio: Consultancy. Heslop: Gilead: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Kiadis: Membership on an entity's Board of Directors or advisory committees; Kuur Therapeutics: Research Funding; GSK: Membership on an entity's Board of Directors or advisory committees; Allovir: Current equity holder in publicly-traded company; Tessa Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Marker Therapeutics: Current equity holder in publicly-traded company; Fresh Wind Biotherapies: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. Rooney: Allogene: Patents & Royalties; Bellicum: Patents & Royalties; Bluebird: Current equity holder in publicly-traded company; Allovir: Current equity holder in publicly-traded company; Alimera: Consultancy; Memgen: Consultancy; TScan Therapeutics: Consultancy; Takeda: Patents & Royalties; Marker: Current equity holder in publicly-traded company; Tessa: Consultancy, Other: Leadership, Research Funding. Vera: Allovir: Consultancy, Current equity holder in publicly-traded company, Other: Leadership, travel , accomodations, expenses, Patents & Royalties; Marker: Current Employment, Other: Travel, Accomodations, Expenses, Patents & Royalties, Research Funding. Leen: Allovir: Consultancy, Current equity holder in publicly-traded company; Marker: Current equity holder in publicly-traded company.


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

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


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 891-891
Author(s):  
Annamaria Gulla ◽  
Eugenio Morelli ◽  
Mehmet K. Samur ◽  
Cirino Botta ◽  
Megan Johnstone ◽  
...  

Abstract Immune therapies including CAR T cells and bispecific T cell engagers are demonstrating remarkable efficacy in relapsed refractory myeloma (MM). In this context, we have recently shown that proteasome inhibitor bortezomib (BTZ) results in immunogenic cell death (ICD) and in a viral mimicry state in MM cells, allowing for immune recognition of tumor cells. Induction of a robust anti-MM immune response after BTZ was confirmed both in vitro and in vivo: treatment of 5TGM1 MM cells with BTZ induced tumor regression associated with memory immune response, confirmed by ELISPOT of mouse splenocytes. We have confirmed the obligate role of calreticulin (CALR) exposure in phagocytosis and the ICD process, since BTZ-induced ICD is impaired in CALR KO MM cells both in vitro and in vivo. We further showed that the therapeutic efficacy of BTZ in patients was correlated with ICD induction: BTZ-induced ICD signature was positively correlated with OS (p=0.01) in patients enrolled in the IFM/DFCI 2009 study. Together, these studies indicate that ICD is associated with long-term response after BTZ treatment. In this work, we reasoned that genomic or transcriptomic alterations associated with shorter survival of MM patients after BTZ treatment may impair activation of the ICD pathway. To this aim, we performed a transcriptomic analysis of purified CD138+ cells from 360 newly diagnosed, clinically-annotated MM patients enrolled in the IFM/DFCI 2009 study. By focusing on genes involved in the ICD process, we found that low levels of GABA Type A Receptor-Associated Protein (GABARAP) were associated with inferior clinical outcome (EFS, p=0.0055). GABARAP gene locus is located on chr17p13.1, a region deleted in high risk (HR) MM with unfavorable prognosis. Remarkably, we found that correlation of low GABARAP levels with shorter EFS was significant (p=0.018) even after excluding MM patients with del17p; and GABARAP is therefore an independent predictor of clinical outcome. GABARAP is a regulator of autophagy and vesicular trafficking, and a putative CALR binding partner. Interestingly, among a panel of MM cell lines (n=6), BTZ treatment failed to induce exposure of CALR and MM cell phagocytosis by DCs in KMS11 cells, which carry a monoallelic deletion of GABARAP. This effect was rescued by stable overexpression of GABARAP. Moreover, CRISPR/Cas9-mediated KO of GABARAP in 3 ICD-sensitive cell lines (AMO1, H929, 5TGM1) abrogated CALR exposure and ICD induction by BTZ. GABARAP add-back by stable overexpression in KO clones restored both CALR exposure and induction of ICD, confirming GABARAP on-target activity. Similarly, pre-treatment of GABARAP KO cells with recombinant CALR restored MM phagocytosis, further confirming that GABARAP impairs ICD via inhibition of CALR exposure. Based on these findings, we hypothesized that GABARAP loss may alter the ICD pathway via CALR trapping, resulting in the ICD resistant phenotype observed in GABARAP null and del17p cells. To this end, we explored the impact of GABARAP KO on the CALR protein interactome, in the presence or absence of BTZ. Importantly, GABARAP KO produced a significant increase of CALR binding to stanniocalcin 1 (STC1), a phagocytosis checkpoint that mediates the mitochondrial trapping of CALR, thereby minimizing its exposure upon ICD. Consistently, GABARAP KO also affected CALR interactome in BTZ-treated cells, which was significantly enriched in mitochondrial proteins. Importantly, co-IP experiments confirmed GABARAP interaction with STC1. These data indicate a molecular scenario whereby GABARAP interacts with STC1 to avoid STC1-mediated trapping of CALR, allowing for the induction of ICD after treatment with ICD inducers; on the other hand, this mechanism is compromised in GABARAP null or del17p cells, and the STC1-CALR complex remains trapped in the mitochondria, resulting in ICD resistance. To functionally validate our findings in the context of the immune microenvironment, we performed mass Cytometry after T cell co-culture with DCs primed by both WT and GABARAP KO AMO1 clones. And we confirmed that treatment of GABARAP KO clones with BTZ failed to activate an efficient T cell response. In conclusion, our work identifies a unique mechanism of immune escape which may contribute to the poor clinical outcome observed in del17p HR MM patients. It further suggests that novel therapies to restore GABARAP may allow for the induction of ICD and improved patient outcome in MM. Disclosures Bianchi: Jacob D. Fuchsberg Law Firm: Consultancy; MJH: Honoraria; Karyopharm: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria. Richardson: AstraZeneca: Consultancy; Regeneron: Consultancy; Protocol Intelligence: Consultancy; Secura Bio: Consultancy; GlaxoSmithKline: Consultancy; Sanofi: Consultancy; Janssen: Consultancy; Takeda: Consultancy, Research Funding; AbbVie: Consultancy; Karyopharm: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; Oncopeptides: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding. Chauhan: C4 Therapeutics: Current equity holder in publicly-traded company; Stemline Therapeutics, Inc: Consultancy. Munshi: Legend: Consultancy; Karyopharm: Consultancy; Amgen: Consultancy; Janssen: Consultancy; Celgene: Consultancy; Oncopep: Consultancy, Current equity holder in publicly-traded company, Other: scientific founder, Patents & Royalties; Abbvie: Consultancy; Takeda: Consultancy; Adaptive Biotechnology: Consultancy; Novartis: Consultancy; Pfizer: Consultancy; Bristol-Myers Squibb: Consultancy. Anderson: Sanofi-Aventis: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Gilead: 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; Bristol Myers Squibb: 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 ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 2302-2302
Author(s):  
Anne-Charlotte Le Floch ◽  
Caroline Imbert ◽  
Aude De Gassart ◽  
Florence Orlanducci ◽  
Aude Le Roy ◽  
...  

Abstract Introduction Vγ9Vδ2 T cells are new promising cytotoxic effectors in hematological malignancies. In acute myeloid leukemia and in non-Hodgkin lymphomas, Vγ9Vδ2 T cells-based immunotherapy has shown encouraging results both in preclinical models and in early phase clinical trials. Acute lymphoblastic leukemia (ALL) includes very heterogeneous clinico-biological entities, for which recent immunotherapy approaches are currently being developed. Nevertheless, global prognosis of ALL patients still be poor with a 5 years-overall survival of less than 40% and therefore, treatments need to be improved. Very few data are currently available on susceptibility of ALL blasts to Vγ9Vδ2 T cell cytotoxic activity. Vγ9Vδ2 T cells are activated by phosphoantigens bound to BTN3A1 on target cells. BTN3A molecules are targeted at clinical level, with the ICT01 agonist monoclonal antibody (mAb), that is currently tested in a multicentric phase ½ study (EVICTION study). Biology of Vγ9Vδ2 T cells has recently undergone a new paradigm with the identification of BTN2A1 as the direct ligand for Vγ9 chain of γδ TCR. BTN2A1 is mandatory for Vγ9Vδ2 T cell activation but its precise role in modulating functions of Vγ9Vδ2 T cells remains unknown. Here, we show that allogenic and autologous Vγ9Vδ2 T cells exert cytolytic functions against ALL cell lines and primary ALL blasts, and we report that Vγ9Vδ2 T cell cytotoxic activity is enhanced after treatment with a unique agonist mAb targeting BTN2A1. Material and methods 5 ALL cell lines (697, RS4;11, NALM-6, HPB-ALL, SUP-T1) and PBMC from 11 adults ALL patients at diagnosis (B-ALL, T-ALL and Ph+ ALL) were tested in functional assays. We evaluated apoptosis of ALL cell lines and of primary ALL blasts after coculture with allogenic Vγ9Vδ2 T cells. ALL samples were also tested for their expansion capacities and a degranulation assay was performed at D14. We assessed in parallel relative quantification of the level expression of BTN2A1 (ICT0302 and 7.48 epitopes), and BTN3A (20.1 and 108.5 epitopes) on surface of ALL blasts. DAUDI-BTN2AKO+2A1 and HEK293-BTN2AKO+2A1 cells were used in binding assays, and modulation of TCR binding was assessed using recombinant tetramerized Vγ9Vδ2 TCR. Results We showed that Vγ9Vδ2 T cells exert spontaneous cytotoxicity against ALL cell lines and primary ALL blasts with a heterogeneous susceptibility depending on the target. We demonstrated that anti-BTN2A1 ICT0302 agonist mAb significantly enhanced Vγ9Vδ2 T cells mediated apoptosis in comparison to control condition, even for the less spontaneously susceptible cells. We confirmed these observations with degranulation of autologous Vγ9Vδ2 T cells expanded from 5 ALL patients at diagnosis that was increased after treatment with anti-BTN2A1 ICT0302 agonist mAb. BTN3A and BTN2A1 were detected on surface of ALL blasts, and BTN3A 108.5 was the most expressed epitope. Interestingly, we observed that anti-BTN2A1 ICT0302 strongly increased binding of a recombinant Vγ9Vδ2 TCR to target cells using with HEK293 and DAUDI cells. Discussion Our results highlighted that Vγ9Vδ2 T cells exert cytolytic functions against ALL cells, both in allogenic and autologous setting and demonstrated that BTN2A1 targeting with our unique agonist mAb could potentiate effector activities of Vγ9Vδ2 T cells against ALL blasts. These results indicate that the sensitization of leukemic cells can be induced by activation BTN3A as well as BTN2A1 mAbs. These data bring novel understanding on the biology of BTN2A1 on leukemic cells and our ability to enhance both binding and function. These findings could be of great interest for the design of innovative Vγ9Vδ2 T cells-based immunotherapy strategies for treating ALL that could be extended to other cancer types. Disclosures De Gassart: ImCheck Therapeutics: Current Employment, Current holder of individual stocks in a privately-held company. Vey: Amgen: Honoraria; BMS: Honoraria; BIOKINESIS: Consultancy, Research Funding; NOVARTIS: Consultancy, Honoraria, Research Funding; SERVIER: Consultancy; JAZZ PHARMACEUTICALS: Honoraria; JANSSEN: Consultancy. Cano: ImCheck Therapeutics: Current Employment, Current holder of individual stocks in a privately-held company. Olive: Emergence Therapeutics: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; Alderaan Biotechnology: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees; ImCheck Therapeutics: Current holder of individual stocks in a privately-held company, Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Anti-BTN2A1 ICT0302 is a murine agonist monoclonal antibody targeting BTN2A1 whose aim is to increase Vgamma9Vdelta2 T cells functions.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 407-407
Author(s):  
Frank Cichocki ◽  
Jode P Goodridge ◽  
Ryan Bjordahl ◽  
Svetlana Gaidarova ◽  
Sajid Mahmood ◽  
...  

Abstract Treatments for B-cell malignancies have improved over the past several decades with clinical application of the CD20-specific antibody rituximab and chimeric antigen receptor (CAR) T cells targeting CD19. Despite the success of these therapies, loss of CD20 after rituximab treatment has been reported in leukemia and lymphoma patients. Additionally, up to 50% of all patients receiving anti-CD19 CAR T-cell therapy relapse within the first year with many of those patients exhibiting CD19 loss. Thus, new therapeutic approaches are needed to address tumor antigen escape. Accordingly, we generated triple gene-modified iPSC-derived NK (iNK) cells, termed "iDuo" NK cells, tailored to facilitate multi-antigen targeting. The iPSC line was clonally engineered to express high-affinity, non-cleavable CD16a (hnCD16), an anti-CD19 CAR optimized for NK cell signaling, and a membrane-bound IL-15/IL-15R fusion (IL-15RF) molecule to enhance NK cell persistence (Fig. 1A). To model antigen escape, we generated CD19 knockout AHR77 lymphoma cells alongside wild type AHR77 cells (both CD20 +) as targets in cytotoxicity assays. Activated peripheral blood NK (PBNK) cells, non-transduced iNK cells, and iDuo NK cells were tested as effectors. Unlike PBNK cells or non-transduced iNK cells, iDuo NK cells efficiently eliminated wild type AHR77 cells with or without the addition of rituximab at all tested E:T ratios. Similarly, iDuo NK cells in combination with rituximab were uniquely able to efficiently eliminate CD19 KO AHR77 cells due to enhanced antibody-dependent cellular cytotoxicity (ADCC) driven by hnCD16 (Fig. 1B-E). Cytotoxicity mediated by iDuo NK cells was also evaluated using primary chronic lymphocytic leukemia (CLL) cells. Compared to expanded PBNK cells and non-transduced iNK cells, only iDuo NK cells (in the absence of rituximab) were able to kill primary CLL cells (Fig. 1F). Expression of IL-15RF by iDuo NK cells uniquely supports in vitro expansion without the need for cytokine supplementation. To determine whether IL-15RF supports in vivo persistence of iDuo NK cells, CD19 CAR iNK cells (lacking IL-15RF) and iDuo NK cells were injected into NSG mice without the addition of cytokines or CD19 antigen availability. iDuo NK cell numbers peaked within a week after injection and persisted at measurable levels for ~5 weeks, in marked contrast to CD19 CAR iNK cell numbers that were undetectable throughout (Fig. 1G). To evaluate the in vivo function of iDuo NK cells, NALM6 leukemia cells were engrafted into NSG mice. Groups of mice received tumor alone or were treated with 3 doses of thawed iDuo NK cells. iDuo NK cells alone were highly effective in this model as evidenced by complete survival of mice in the treatment group (Fig. 1H). To assess iDuo NK cells in a more aggressive model, Raji lymphoma cells were engrafted, and groups of mice received rituximab alone, iDuo NK cells alone, or iDuo NK cells plus rituximab. Mice given the combination of iDuo NK cells and rituximab provided extended survival compared to all other arms in the aggressive disseminated Raji lymphoma xenograft model (Fig. 1I). One disadvantage of anti-CD19 CAR T cells is their inability to discriminate between healthy and malignant B cells. Because NK cells express inhibitory receptors that enable "self" versus "non-self" discrimination, we reasoned that iDuo NK cells could have higher cytotoxicity against tumor cells relative to healthy B cells. To address this, we labeled Raji cells, CD19 + B cells from healthy donor peripheral blood mononuclear cells (PBMCs) and CD19 - PBMCs. Labeled populations of cells were co-cultured with iDuo NK cells, and specific killing was analyzed. As expected, iDuo NK cells did not target CD19 - PBMCs. Intriguingly, iDuo NK cells had much higher cytotoxic activity against Raji cells compared to primary CD19 + B cells, suggesting a preferential targeting of malignant B cells compared to healthy B cells. Together, these results demonstrate the potent multi-antigen targeting capability and in vivo antitumor function of iDuo NK cells. Further, these data suggest that iDuo NK cells may have an additional advantage over anti-CD19 CAR T cells by discriminating between healthy and malignant B cells. The first iDuo NK cell, FT596, is currently being tested in a Phase I clinical trial (NCT04245722) for the treatment of B-cell lymphoma. Figure 1 Figure 1. Disclosures Cichocki: Gamida Cell: Research Funding; Fate Therapeutics, Inc: Patents & Royalties, Research Funding. Bjordahl: Fate Therapeutics: Current Employment. Gaidarova: Fate Therapeutics, Inc: Current Employment. Abujarour: Fate Therapeutics, Inc.: Current Employment. Rogers: Fate Therapeutics, Inc: Current Employment. Huffman: Fate Therapeutics, Inc: Current Employment. Lee: Fate Therapeutics, Inc: Current Employment. Szabo: Fate Therapeutics, Inc: Current Employment. Wong: BMS: Current equity holder in publicly-traded company; Fate Therapeutics, Inc: Current Employment. Cooley: Fate Therapeutics, Inc: Current Employment. Valamehr: Fate Therapeutics, Inc.: Current Employment. Miller: Magenta: Membership on an entity's Board of Directors or advisory committees; ONK Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees; Vycellix: Consultancy; GT Biopharma: Consultancy, Patents & Royalties, Research Funding; Fate Therapeutics, Inc: Consultancy, Patents & Royalties, Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees; Wugen: Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 807-807
Author(s):  
Marco Ruella ◽  
Shannon L Maude ◽  
Boris Engels ◽  
David M. Barrett ◽  
Noelle Frey ◽  
...  

Abstract Introduction. Anti-CD19 chimeric antigen receptor T cells (CART19 or CTL019) have shown impressive clinical activity in B-cell acute lymphoblastic leukemia (B-ALL) and are poised to receive FDA approval. However, some patients relapse after losing CD19 expression. Since CD22 remains highly expressed in relapsed/refractory (r/r) B-ALL even in these patients, anti-CD22 CART (CART22) have been developed. The National Cancer Institute (NCI) reported 4/9 complete remission (CR) in patients receiving CART22, with 100% CR at the highest T cell dose (NCT02315612)(S hah NN, ASH 2016 #650). Patients and Methods. We generated a second-generation CAR22 differing from that used by the NCI only by the use of a longer linker [4x(GGGGS); LL vs. 1x(GGGGS); SL] between the light and heavy chains of the scFv (Fig. 1 A). This construct was tested in two pilot clinical trials in adults (NCT02588456)and children with r/r-ALL (NCT02650414). CART22 cells were generated using lentiviral transduction as in our previous studies. The protocol-specified CART22 dose was 2x106-1x107 cells/kg for pediatric patients <50kg and 1-5x108 for pediatric patients ≥50kg and adult patients,. infused after lymphodepleting chemotherapy. Patient characteristics are described in Table 1. For the adult trial, 5 patients were screened, 4 enrolled (1 patient withdrew consent) and 3 infused (1 manufacturing failure). For the pediatric trial, 9 patients were screened, 8 enrolled (1 screen failure) and 6 infused (two patients were not infused for disease progression). For the preclinical studies, we generated CART22LL and CART22SL and tested them in vivo using xenograft models. NOD-SCID gamma chain deficient (NSG) mice were engrafted with either a luciferase+ standard B-ALL cell line (NALM6) or primary B-ALL cells obtained from a patient relapsing after CART19 (CHP110R). We also used 2-photon imaging to study the in vivo behavior and immune synapse formation and flow cytometry to asses T cell activation. Results. CART22 cells were successfully manufactured for 10/12 patients. In the adult cohort 3/3 patients developed CRS (gr.1-3) and no neurotoxicity was observed; in the pediatric cohort out of 5 evaluable patients (1 discontinued for lineage switch to AML on pre-infusion marrow), 3/5 developed cytokine-release syndrome (CRS) (all grade 2) and 1 patient had encephalopathy (gr.1). CART22 cells expanded in the PB with median peak of 1977 (18-40314) copies/ug DNA at day 11-18. Interestingly, in an adult patient who had previously received CART19 a second CART19 re-expansion was observed following CART22 expansion (Fig 1 B). At day 28, in the adult cohort the patient who was infused in morphologic CR remained in CR, while the other 2 had no response (NR); in the pediatric cohort 2/5 patients were in CR, 1 in partial remission (PR) that then converted to CR with incomplete recovery at 2 months, and 2 NR. No CD22-negative leukemia progression was observed. Since our results with a long linker appeared inferior compared to the previously reported CART22 trial (short linker), we performed a direct comparison of the 2 different CAR22 constructs. In xenograft models, CART22SL significantly outperformed CART22LL (Fi 1 C) with improved overall survival. Moreover, CART22SL showed higher in vivo proliferation at day 17 (Fig 1 D). Mechanistically, intravital 2-photon imaging showed that CART22SL established more protracted T cell:leukemia interactions than did CART22LL, suggesting the establishment of productive synapses (Fig 1 E). Moreover, in vivo at 24 hrs higher T cell activation (CD69, PD-1) was observed in CART22SL from the BM of NALM-6-bearing mice. Conclusions. Here we report the results of two pilot clinical trials evaluating the safety and feasibility of CART22 therapy for r/r B-ALL. Although feasible and with manageable toxicity CART22LL led to modest clinical responses. Preclinical evaluation allowed us to conclude that shortening the linker by 15 amino acids significantly increases the anti-leukemia activity of CART22, possibly by leading to more effective interactions between T cells and their targets. Finally, with the caveats of cross-trial comparison, our data suggest that xenograft models can predict the clinical efficacy of CART products and validate the use of in vivo models for lead candidate selection Disclosures Ruella: Novartis: Patents & Royalties, Research Funding. Maude: Novartis Pharmaceuticals: Consultancy, Other: Medical Advisory Boards. Engels: Novartis: Employment. Frey: Novartis: Research Funding. Lacey: Novartis: Research Funding; Genentech: Honoraria. Melenhorst: Novartis: Research Funding. Brogdon: Novartis: Employment. Young: Novartis: Research Funding. Porter: Incyte: Honoraria; Novartis: Honoraria, Patents & Royalties, Research Funding; Immunovative Therapies: Other: Member DSMB; Genentech/Roche: Employment, Other: Family member employment, stock ownship - family member; Servier: Honoraria, Other: Travel reimbursement. June: WIRB/Copernicus Group: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celldex: Honoraria, Membership on an entity's Board of Directors or advisory committees; Immune Design: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Novartis: Patents & Royalties, Research Funding; Tmunity Therapeutics: Equity Ownership, Research Funding. Grupp: Jazz Pharmaceuticals: Consultancy; Novartis Pharmaceuticals Corporation: Consultancy, Other: grant; University of Pennsylvania: Patents & Royalties; Adaptimmune: Consultancy. Gill: Novartis: Patents & Royalties, Research Funding.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2374-2374
Author(s):  
Seong Lin Khaw ◽  
David C. Huang ◽  
Simon He ◽  
John F Seymour ◽  
Dennis Carney ◽  
...  

Abstract Abstract 2374 Poster Board II-351 ABT-263 is a first-in-class BH3 mimetic inhibitor of 3 pro-survival members of the BCL2 protein family (BCL2, BCLXL, BCLW). Consistent with potent activity against BCL2-overexpressing cell lines and primary CLL cells in vitro, and BCL2-overexpressing lymphoid murine tumors in vivo, ABT-263 demonstrated significant antitumor activity in pts with relapsed, refractory CLL and small lymphocytic lymphoma (SLL) in 2 phase 1/2a studies. To date, 42 pts (35 evaluable) with CLL/SLL have been treated with ABT-263 (40-440 mg/d). 51% (18/35) with a baseline lymphocytosis >5,000 have achieved '50% reduction in lymphocytosis, while 34% (12/35; 5 bulky disease) with measurable nodal disease at initiation have achieved a partial response. Overall, some manifestation of antitumor activity was observed in 60% (21/35). Responses tend to be durable, with the median PFS not reached as yet while the median time on study for M06-873 pts is 9 mos for pts on the M06-873 study. Responses were observed in pts who received >4 lines of prior therapy and in those who were fludarabine refractory and/or had bulky disease. BCL2 is highly expressed in all CLL/SLL, yet only a subset of pts responded. We tested whether additional intrinsic biological characteristics of CLL were associated with response to ABT-263 in vivo. Potential biomarkers, both standard (FISH for 17p13, 11q22.3) and investigational (in vitro sensitivity; quantitative expression of BCL2, MCL1, BIM, BAX) were measured at study entry, during therapy and where possible at progression in a subset of pts treated in the phase 1 study in CLL (M06-873). Of 21 pts receiving >40mg/d ABT-263 for >7d, FISH data for 17p13 and 11q22.3 were available for 16, of which only 5 were normal; 4 and 6 had deleted 17p13 or 11q22.3 respectively, and 2 had deletions for both in >5% of cells examined. Similar majorities of pts with del17p13 (4/6) or del11q22.3 (5/8), or with neither abnormality (4/5), achieved either a >50% fall in peripheral blood lymphocytes, reduction in nodal size, or both. None of the pts without del17p13 or del11q22.3 have progressed after median 285 d (range 167-484 d) on drug, while only 1/6 with del17p13 and 2/8 with del11q22.3 have progressed (all 3 within 3 mos). CLL cells from 12 pts were tested for in vitro sensitivity to ABT-737, a BH3 mimetic with the same specificity and activity in vitro as ABT-263. LC50 were all <50 nM at baseline (mean 5.5±5.1 nM). LC50 at baseline correlated inversely with % reduction of lymphocytosis at both Cycle1/Day 14 (C1D14) and C3D1 (r2=-0.51 & 0.44, p=0.01 & 0.03, respectively), although in vitro LC50 was not predictive of whether a partial response was ultimately achieved. Reassessment of in vitro LC50 after 14 days on ABT-263 and at C3D1 revealed a modest reduction in sensitivity of residual CLL cells: C1D14 12±9.4 nM, C3D1 11±9.6 nM (p<0.05 for difference between baseline and later timepoints; repeated measures ANOVA). Expression levels of BCL2, BIM and BAX did not correlate with % reduction in lymphocytosis at either C1D14 or C3D1 in vivo responses. Higher basal expression of MCL1 was negatively correlated with % reduction in lymphocytes after 2 cycles (n=8; r2 = -0.55, p=0.03). When MCL1 expression was measured in residual CLL cells collected at C1D14 or C3D1, no change from baseline was observed. These preliminary data indicate that ABT-263 is active in pts with relapsed refractory CLL carrying adverse genetic markers, and that expression patterns of BCL2 family member proteins do not strongly predict response to this drug. While in vitro LC50 did correlate with the degree of initial fall in lymphocytosis, residual cells after 2 treatment cycles were only modestly less intrinsically sensitive in vitro, expressing higher levels of MCL1. Additional factors, presumably extrinsic to the CLL cells appear to significantly influence in vivo responses to ABT-263. Disclosures: Off Label Use: ABT-263 is an experimental drug that is not yet registered. It is designed to induce apoptosis in tumor cells.. Seymour:Bayer Schering: Consultancy, Membership on an entity's Board of Directors or advisory committees, Travel grants; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Travel Grants. Chyla:Abbott: Employment. Litvinovich:Abbott: Employment. McKeegan:Abbott: Employment. Krivoshik:Abbott: Employment. Enschede:Abbott: Employment. Humerickhouse:Abbott: Employment. Roberts:Abbott : Research Funding; Genentech: Research Funding.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3266-3266
Author(s):  
Sabine Tschiedel ◽  
Melanie Adler ◽  
Karoline Schubert ◽  
Annette Jilo ◽  
Enrica Mueller ◽  
...  

Abstract Abstract 3266 Poster Board III-1 Introduction: NmE2 (Nm23-H2, NDP kinase B) is one of a family of proteins that catalyze the transfer of gamma-phosphate between nucleoside-triphosphates and diphosphates. The two major family members, NmE1 and NmE2 are strongly implicated in the control of differentiation, proliferation, migration and apoptosis via interactions which are often independent of their kinase activity, NmE2 being a transcriptional activator of the c-myc gene. We recently identified NmE2 as a tumour associated, HLA-A32+ restricted, antigen in a patient with CML and found the protein (but not the mRNA) to be generally over expressed in CML but not in other haematological malignancies. We also detected a specific T-cell response in peripheral blood cells of a patient 5 years after transplantation. This identifies NmE2 as a potential target for both molecular and immunotherapy of CML. However, the development of immunotherapeutic approaches will depend on the ability of NmE2 to function as a tumour antigen in common HLA backgrounds. The aims of this study were firstly to investigate the antigenicity of NmE2 in the HLA-A2 background (which accounts for more than 50% of the Caucasian population), and secondly to characterise the regulatory relationship between Bcr/Abl and NmE2 using a cell line model of CML. Materials and Methods: 5 nonameric NmE2 peptides with predicted anchor amino acids for HLA-A2 were loaded at concentrations of 10μM separately onto HLA-A2 expressing antigen presenting cells. Elispot Assays were carried out with CD8+ MLLCs (for the identification of antigenic peptides) or CD8+ cells isolated directly from a CML patient at different time points after HCT. Ba/F3 cells stably expressing wild type and mutant forms of Bcr/Abl were treated with imatinib and nilotinib (0 – 10 μM) for 48h. Bcr/Abl activity was assessed by FACS using antibodies specific for the phosphorylated forms of CrkL and Stat5. NmE2 and c-Myc protein were detected by immunocytochemistry and Western blotting with specific antibodies [Santa Cruz, clones L-16 and 9E10 respectively]. Levels of nme2 and c-myc mRNA were determined by quantitative real time PCR. Results: Full length NmE2 protein and 2 of 5 HLA-A2 anchor-containing peptides tested (NmE2132–140 and NmE2112–120) were specifically recognized by the HLA-A2+ CD8+ MLLC, demonstrating the antigenicity of NmE2 in the HLA-A2 background in vitro. Furthermore, while CD8+ T-cells from a transplanted HLA-A2+ CML patient showed little or no specific reactivity in the first 10 months after HCT, a distinct reactivity (up to 0.6 % NmE2 reactive CD8+ T cells) became apparent at later stages, consistent with the development of an immune response against NmE2-expressing cells in vivo. The patient remained negative for bcr/abl transcripts throughout this period. BA/F3 Bcr/Abl cells expressed increased levels of NmE2 protein (but not mRNA) compared to the parent BA/F3 line. Interestingly, treatment with imatinib or nilotinib reduced NmE2 protein expression in BA/F3 Bcr/Abl, but not in cells expressing Bcr/Abl mutants resistant to the respective inhibitors. Treatment of BA/F3 Bcr/Abl cells with the PI3K inhibitor Ly294002 resulted in reduced Bcr/Abl activity and a corresponding reduction in both c-Myc and NmE2 protein levels, without affecting mRNA levels. Conclusion: The over expression of NmE2 is closely linked to Bcr/Abl kinase activity, the predominant level of regulation being post-transcriptional and dependent on PI-3K activity. The NmE2 protein is restricted by HLA-A2 as well as by HLA-A32. The development of an NmE2-specific T-cell response in a CML patient after stem cell transplantation suggests that NmE2 functions as a tumour antigen in HLA-A2+ patients in vivo and may be relevant to the long term immune control of CML. NmE2 is therefore a promising candidate for the development of new immunotherapeutic strategies for the treatment of CML. Disclosures: Lange: BMS: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Niederwieser:BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Research Funding.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 16-17 ◽  
Author(s):  
Martin Hutchings ◽  
Fritz C. Offner ◽  
Francesc Bosch ◽  
Giuseppe Gritti ◽  
Carmelo Carlo-Stella ◽  
...  

Background: Up to 50% of patients suffering from Non-Hodgkin`s lymphoma (NHL) become refractory to or relapse after treatment (M. Crump, Blood 2017). With this, the lack of curative outcomes for patients with both indolent and aggressive NHL subtypes remains an unmet medical need. The CD20 CD3 T cell bispecific antibody glofitamab induces specific T-cell activation and has demonstrated significant single agent activity in r/r NHL patients (NP30179 study, M. Dickinson, EHA 2020, Abstract S241). RO7227166, a CD19 targeted 4-1BBL (CD137) costimulatory agonist has shown synergistic anti-tumor activity when combined with glofitamab in preclinical models (fig 1). RO7227166 is a bispecific antibody-like fusion protein composed of a split trimeric 4-1BB ligand, a tumor antigen-targeting moiety recognizing CD19, and a silent Fc part preventing Fc-mediated toxicity. 4-1BB is an inducible co-stimulatory molecule expressed by activated T-cells or NK cells. Through CD19-binding, the 4-1BB ligand moiety can deliver co-stimulatory signals to activated T- and NK-cell subsets in the tumor. The expected mode of action (MoA) for this molecule is to deliver a costimulatory signal 2 to enhance the effector function of tumor-infiltrating T cells or NK cells upon their activation (signal 1) by a T-cell bispecific antibody (e.g. glofitamab, RO7082859) or a tumor-targeted ADCC antibody (e.g. obinutuzumab). By delivering direct T-cell-target cell engagement followed by costimulatory activation the aim is to offer a highly active off-the-shelf immunotherapy combination. Methods: RO7227166 is being developed in combination with glofitamab and obinutuzumab in a phase I, open-label, dose-escalation study BP41072 (NCT04077723). The study is designed to evaluate the combination maximum tolerated dose (MTD), safety, tolerability, pharmacokinetic (PK), and/or pharmacodynamic (PD) profile of escalating doses of RO7227166, and to evaluate preliminary anti-tumor activity in participants with r/r NHL. The dose escalation stage is divided into Part I (combination with obinutuzumab) and Part II (combination with glofitamab) followed by an expansion stage (Part III). During Part I patients receive 1000mg obinutuzumab intravenously (IV) at a q3w schedule in combination with CD19 4-1BBL IV. During part II glofitamab is given in a q3w schedule with RO7227166 introduced at C2D8 and administered concomitantly from C3D1 onwards. A fixed dose of obinutuzumab (Gpt; pre-treatment) is administered seven days prior to the first administration of RO7227166 and seven days prior to the first administration of glofitamab (M. Bacac, Clin Cancer Res 2018; M. Dickinson, EHA 2020, Abstract S241). Patients will initially be recruited into part I of the study only using single-participant cohorts, where a rule-based dose-escalation is implemented, with dosing initiated at 5 μg (flat dose). As doses of RO7227166 increase, multiple participant cohorts will be recruited and dose-escalation will be guided by the mCRM-EWOC design for overdose control. Commencement of Part II including decision on the RO7227166 starting dose will be guided by safety and PK data from Part I. Patients with r/r NHL meeting standard organ function criteria and with adequate blood counts will be eligible. The maximum duration of the study for each participant will be up to 24 months in Part I (excluding survival follow-up) and up to 18 months in Part II and Part III. Tumor biopsies and peripheral blood biomarker analyses will be used to demonstrate MoA and proof of concept of an off the shelf flexible combination option providing signals 1 and 2. Disclosures Hutchings: Takeda: Honoraria; Takeda: Research Funding; Genmab: Honoraria; Roche: Honoraria; Genmab: Research Funding; Janssen: Research Funding; Novartis: Research Funding; Sankyo: Research Funding; Roche: Consultancy; Genmab: Consultancy; Takeda: Consultancy; Roche: Research Funding; Celgene: Research Funding; Daiichi: Research Funding; Sanofi: Research Funding. Bosch:Hoffmann-La Roche: Research Funding. Gritti:Italfarmaco: Consultancy; F. Hoffmann-La Roche Ltd: Honoraria; Jannsen: Other: Travel Support; Autolus: Consultancy; IQVIA: Consultancy; Kite: Consultancy; Takeda: Honoraria; Amgen: Honoraria. Carlo-Stella:Bristol-Myers Squibb, Merck Sharp & Dohme, Janssen Oncology, AstraZeneca: Honoraria; Servier, Novartis, Genenta Science srl, ADC Therapeutics, F. Hoffmann-La Roche, Karyopharm, Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; ADC Therapeutics and Rhizen Pharmaceuticals: Research Funding; Boehringer Ingelheim and Sanofi: Consultancy. Townsend:Roche, Gilead: Consultancy, Honoraria. Morschhauser:Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Servier: Consultancy; Janssen: Honoraria; Epizyme: Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Genentech, Inc.: Consultancy. Cartron:Celgene: Consultancy, Honoraria; F. Hoffmann-La Roche: Consultancy, Honoraria; Sanofi: Honoraria; Abbvie: Honoraria; Jansen: Honoraria; Gilead: Honoraria. Ghesquieres:CELGENE: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Roche: Consultancy, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Gilead: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Janssen: Honoraria. de Guibert:Gilead Sciences: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria; Janssen: Consultancy, Honoraria. Herter:Roche Glycart AG: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties. Korfi:Roche Diagnostics GmbH: Consultancy. Craine:Roche: Current Employment. Mycroft:Roche: Current Employment. Whayman:Roche: Current Employment. Mueller:Roche: Current Employment. Dimier:Roche: Current Employment. Moore:Roche: Current Employment. Belli:Roche Pharma: Current Employment. Kornacker:Hoffmann-La Roche Ltd.: Current Employment, Current equity holder in publicly-traded company. Lechner:Roche Diagnostics GmbH: Current Employment, Current equity holder in publicly-traded company. Dickinson:Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Merck Sharp & Dohme: Consultancy; Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 75-75
Author(s):  
Jooeun Bae ◽  
Shuichi Kitayama ◽  
Laurence Daheron ◽  
Zach Herbert ◽  
Nikhil C. Munshi ◽  
...  

Abstract T cell regenerative medicine represents an emerging immunotherapeutic approach using antigen-specific Induced Pluripotent Stem Cells (iPSC) to rejuvenate CD8 + cytotoxic T lymphocytes (CTL). Here we report on an iPSC-derived therapeutic strategy targeting B-Cell Maturation Antigen (BCMA) against multiple myeloma (MM) via establishment of antigen-specific iPSC, followed by differentiation into highly functional BCMA-specific CD8 + CTL. The reprogrammed BCMA-specific iPSC displayed normal karyotypes and pluripotency potential as evidenced by expression of stem cell markers (SSEA-4, TRA1-60) and alkaline phosphatase, along with differentiation into three germ layers (Ectoderm, Mesoderm, Endoderm). During embryoid body formation, BCMA-specific iPSC further polarized into the mesoderm germ layer, evidenced by the activation of SNAI2, TBX3, PLVAP, HAND1 and CDX2 transcriptional regulators. Next, the BCMA-specific iPSC clones committed to CD8 + T cell differentiation were characterized by analyzing their hematopoietic progenitor cells (HPC; CD34 + CD43 +/CD14 - CD235a -) for specific transcriptional regulation. RNAseq analyses indicated a low variability and similar profiles of gene transcription within the iPSC clones committed to CD8 + CTL compared to increased transcriptional variability within iPSC clones committed to different cell types. The unique transcriptional profiles of the iPSC committed to CD8 + T cells included upregulation of transcriptional regulators controlling CD4/CD8 T cell differentiation ratio, memory CTL formation, NF-kappa-B/JNK pathway activation, and cytokine transporter/cytotoxic mediator development, as well as downregulation of regulators controlling B and T cell interactions, CD4 + Th cells, and inhibitory receptor development. Specifically, a major regulatory shift, indicated by upregulation of specific genes involved in immune function, was detected in HPC from the iPSC committed to CD8 + T cells. BCMA-specific T cells differentiated from the iPSC were characterized as displaying mature CTL phenotypes including high expression of CD3, CD8a, CD8b, TCRab, CD7 along with no CD4 expression (Fig. 1). In addition, the final BCMA iPSC-T cells were predominantly CD45RO + memory cells (central memory and effector memory cells) expressing high level of T cell activation (CD38, CD69) and costimulatory (CD28) molecules. Importantly, these BCMA iPSC-T cells lacked immune checkpoints (CTLA4, PD1, LAG3, Tim3) expression and regulatory T cells induction, distinct from other antigen-stimulated T cells. The rejuvenated BCMA iPSC-T cells demonstrated a high proliferative (1,000 folds increase) during the differentiation process as well as poly-functional anti-tumor activities and Th1 cytokine (IFN-g, IL-2, TNF-a) production triggered in response to MM patients' cells in HLA-A2-restricted manner (Fig. 2). Furthermore, the immune responses induced by these BCMA iPSC-T cells were specific to the parent heteroclitic BCMA 72-80 (YLMFLLRKI) peptide used to reprogram and establish the antigen-specific iPSC. Evaluation of 88 single cell Tetramer + CTL from the BCMA iPSC-T cells revealed a clonotype of unique T cell receptor (TCRa, TCRb) sequence. The BCMA-specific iPSC clones maintained their specific differentiation potential into the antigen-specific CD8 + memory T cells, following multiple subcloning in long-term cultures under feeder-free conditions or post-thaw after long-term (18 months) cryopreservation at -140 oC, which provides additional benefits to treat patients in a continuous manner. Taken together, rejuvenated CD8 + CTL differentiated from BCMA-specific iPSC were highly functional with significant (*p &lt; 0.05) levels of anti-MM activities including proliferation, cytotoxic activity and Th-1 cytokine production. Therefore, the antigen-specific iPSC reprogramming and T cells rejuvenation process can provide an effective and long-term source of antigen-specific memory CTL lacking immune checkpoints and suppressors for clinical application in adoptive immunotherapy to improve patient outcome in MM. Figure 1 Figure 1. Disclosures Munshi: Amgen: Consultancy; Karyopharm: Consultancy; Takeda: Consultancy; Adaptive Biotechnology: Consultancy; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy; Abbvie: Consultancy; Janssen: Consultancy; Legend: Consultancy; Oncopep: Consultancy, Current equity holder in publicly-traded company, Other: scientific founder, Patents & Royalties; Novartis: Consultancy; Pfizer: Consultancy. Ritz: Amgen: Research Funding; Equillium: Research Funding; Kite/Gilead: Research Funding; Avrobio: Membership on an entity's Board of Directors or advisory committees; Akron: Consultancy; Biotech: Consultancy; Blackstone Life Sciences Advisor: Consultancy; Clade Therapeutics, Garuda Therapeutics: Consultancy; Immunitas Therapeutic: Consultancy; LifeVault Bio: Consultancy; Novartis: Consultancy; Rheos Medicines: Consultancy; Talaris Therapeutics: Consultancy; TScan Therapeutics: Consultancy. Anderson: Sanofi-Aventis: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Millenium-Takeda: Membership on an entity's Board of Directors or advisory committees; Janssen: 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; 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.


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