scholarly journals 783 SGN-PDL1V, a novel, investigational PD-L1-directed antibody-drug conjugate for the treatment of solid tumors

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A818-A818
Author(s):  
Byron Kwan ◽  
Megan Ramirez ◽  
Steven Jin ◽  
Changpu Yu ◽  
Serena Wo ◽  
...  
Keyword(s):  
Immune Checkpoint ◽  
Safety Profile ◽  
Cell Lymphoma ◽  
Brentuximab Vedotin ◽  
Programmed Death ◽  
Xenograft Models ◽  
Human Primate ◽  
Antibody Drug

BackgroundPD-1/PD-L1 immune checkpoint inhibitors have transformed oncology, but a significant unmet need persists for patients with relapsed/refractory tumors following PD-1/PD-L1 treatment. PD-L1 is expressed in patients across a broad spectrum of tumor types and displays limited normal tissue expression, highlighting the potential of PD-L1 as a target for antibody-drug conjugates (ADCs) in addition to its role as an immune checkpoint. SGN-PDL1V is a PD-L1-directed ADC currently under preclinical investigation, which is comprised of an anti-PD-L1 antibody conjugated to the vedotin drug-linker. The vedotin drug-linker, consists of the microtubule disrupting agent, monomethyl auristatin E (MMAE), and a protease-cleavable peptide linker, which has been clinically validated in multiple ADC programs including brentuximab vedotin, enfortumab vedotin and polatuzumab vedotin.1–3 The proposed SGN-PDL1V primary mechanism of action is direct cytotoxicity against PD-L1-expressing malignant cells through delivery of the MMAE payload. Additionally, MMAE induces immunogenic cell death, leading to subsequent immune activation in the tumor microenvironment.4 Here, we characterize the preclinical activity and tolerability of SGN-PDL1V.MethodsSGN-PDL1V cytotoxicity was evaluated using PD-L1 expressing tumor cell lines in vitro and xenograft tumor models in vivo. Inhibition of the PD-1/PD-L1 immune checkpoint was assessed in a luminescent reporter system in vitro and a syngeneic tumor model in vivo. The tolerability and safety profile of SGN-PDL1V was determined in a non-human primate study.ResultsIn vitro, SGN-PDL1V demonstrated internalization and potent cytotoxic activity against PD-L1 expressing tumor cells. In vivo, SGN-PDL1V achieved tumor regressions in multiple tumor xenograft models at doses as low as 1 mg/kg when dosed weekly for a total of three doses. This activity was observed in immunocompromised mice, which lack responses to PD-1/PD-L1 inhibition. Notably, activity was observed even in xenograft models with low, heterogeneous PD-L1 expression, supporting the possibility to treat patients across a wide range of PD-L1 expression levels. Additionally, SGN-PDL1V exhibited potential to inhibit the PD-1/PD-L1 checkpoint in vitro and in vivo. The tolerability and safety profile of SGN-PDL1V were assessed in a non-human primate study and found to be comparable to other FDA-approved vedotin ADCs.ConclusionsSGN-PDL1V is a promising PD-L1 directed ADC with a unique cytotoxic mechanism of action among other PD-L1-targeted therapeutics. SGN-PDL1V demonstrated robust activity in multiple preclinical models and comparable tolerability and safety profile to other vedotin ADCs in non-human primates. Collectively, these data support further evaluation of SGN-PDL1V in a planned, first-in-human Phase 1 study.AcknowledgementsWe would like to thank Kerry Klussman for assay support and Jamie Mitchell for conjugation support.Trial RegistrationN/AReferencesSenter PD, Sievers EL. The discovery and development of brentuximab vedotin for use in relapsed Hodgkin lymphoma and systemic anaplastic large cell lymphoma. Nat Biotechnol 2012;30(7):631–7. Epub 2012/07/12. doi: 10.1038/nbt.2289. PubMed PMID: 22781692.Rosenberg JE, O'Donnell PH, Balar AV, McGregor BA, Heath EI, Yu EY, et al. Pivotal trial of enfortumab vedotin in urothelial carcinoma after platinum and anti-programmed death 1/Programmed death ligand 1 therapy. J Clin Oncol 2019;37(29):2592–600. Epub 2019/07/30. doi: 10.1200/JCO.19.01140. PubMed PMID: 31356140; PubMed Central PMCID: PMC6784850.Tilly H, Morschhauser F, Bartlett NL, Mehta A, Salles G, Haioun C, et al. Polatuzumab vedotin in combination with immunochemotherapy in patients with previously untreated diffuse large B-cell lymphoma: an open-label, non-randomised, phase 1b-2 study. Lancet Oncol 2019;20(7):998–1010. Epub 2019/05/19. doi: 10.1016/S1470-2045(19)30091-9. PubMed PMID: 31101489.Klussman K, Tenn E, Higgins S, Mazahreh R, Snead K, Hamilton J, Grogan B, Sigurjonsson J, Cao A, Gardai S, Liu B. 618 Vedotin ADCs induce ER stress and elicit hallmarks of ICD across multiple cancer indications. J Immunother Cancer 2020;8(Suppl 3):A372. DOI:10.1136/jitc-2020-SITC2020.0618.Ethics ApprovalAll animal studies were conducted in accordance with protocols reviewed and approved by the Institutional Animal Care and Use Committee at Seagen or the external testing facility that conducted the studies.

scholarly journals 854 SGN-B7H4V, a novel, investigational vedotin antibody-drug conjugate directed to the T cell checkpoint ligand B7-H4, shows promising activity in preclinical models

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A895-A895
Author(s):  
Elizabeth Gray ◽  
Angela Epp ◽  
Michelle Ulrich ◽  
Disha Sahetya ◽  
Kelly Hensley ◽  
...  
Keyword(s):  
Solid Tumor ◽  
Immune Checkpoint ◽  
Brentuximab Vedotin ◽  
Preclinical Models ◽  
Antibody Drug Conjugate ◽  
Drug Conjugate ◽  
Tumor Types ◽  
Antibody Drug

BackgroundSGN-B7H4V is a novel, investigational vedotin antibody drug conjugate (ADC) directed to B7-H4, a member of the B7 family of immune checkpoint ligands. B7-H4 expression is elevated on a variety of solid tumors including breast, ovarian, and endometrial tumors.1 SGN-B7H4V is composed of a fully human IgG1 anti-B7-H4 monoclonal antibody (mAb) conjugated to the microtubule disrupting agent monomethyl auristatin E (MMAE) via a protease-cleavable peptide linker. SGN-B7H4V is designed to bind and internalize the immune checkpoint ligand B7-H4/ADC complex from the surface of malignant cells and release the cytotoxic payload MMAE. This ”vedotin” drug linker system has been clinically validated by multiple ADC programs, including brentuximab vedotin, enfortumab vedotin, and polatuzumab vedotin.2–4 Here, we characterize the target antigen B7-H4 and evaluate SGN-B7H4V activity in preclinical models.MethodsB7-H4 expression was characterized by RNA expression and immunohistochemistry across multiple solid tumor types. The ability of SGN-B7H4V to kill B7-H4-expressing tumor cells in vitro and in vivo in a variety of xenograft tumor models was also evaluated. Finally, the tolerability of SGN-B7H4V was assessed in rodent and non-human primate toxicology studies.ResultsImmunohistochemistry confirmed expression of B7-H4 across multiple solid tumor types, including ovarian and breast tumors. In vitro, upon binding to SGN-B7H4V, the immune checkpoint ligand B7-H4 was rapidly internalized and delivered the cytotoxic payload MMAE. Moreover, SGN-B7H4V killed B7-H4-expressing tumor cells in vitro by MMAE-mediated cytotoxicity, antibody-dependent cellular cytotoxicity (ADCC), and antibody-dependent cellular phagocytosis (ADCP). In vivo, SGN-B7H4V demonstrated strong anti-tumor activity in multiple xenograft models, including ovarian and breast cancer models. Activity was observed in models with both uniformly high and heterogeneous expression of B7-H4, consistent with robust bystander activity of vedotin ADCs. Finally, SGN-B7H4V was tolerated in both rat and non-human primate (NHP) toxicology studies at doses consistent with approved vedotin ADCs.ConclusionsB7-H4 is a promising ADC target expressed by several solid tumor types. SGN-B7H4V demonstrates robust anti-tumor activity in preclinical models through multiple potential mechanisms and is tolerated in rat and NHP toxicity studies. Altogether, these data support further evaluation of SGN-B7H4V in a planned, first-in-human phase 1 clinical study.AcknowledgementsWe would like to thank Kellie Spahr for conjugation support and Martha Anderson for in vivo biology support.ReferencesLeong SR, Liang WC, Wu Y, Crocker L, Cheng E, Sampath D, et al. An anti-B7-H4 antibody-drug conjugate for the treatment of breast cancer. Mol Pharm 2015;12(6):1717–29. Epub 2015/04/09. doi: 10.1021/mp5007745. PubMed PMID: 25853436.Rosenberg JE, O’Donnell PH, Balar AV, McGregor BA, Heath EI, Yu EY, et al. Pivotal trial of enfortumab vedotin in urothelial carcinoma after platinum and anti-programmed death 1/programmed death ligand 1 therapy. J Clin Oncol 2019;37(29):2592–600. Epub 2019/07/30. doi: 10.1200/JCO.19.01140. PubMed PMID: 31356140; PubMed Central PMCID: PMC.Senter PD, Sievers EL. The discovery and development of brentuximab vedotin for use in relapsed Hodgkin lymphoma and systemic anaplastic large cell lymphoma. Nat Biotechnol 2012;30(7):631–7. Epub 2012/07/12. doi: 10.1038/nbt.2289. PubMed PMID: 22781692.Tilly H, Morschhauser F, Bartlett NL, Mehta A, Salles G, Haioun C, et al. Polatuzumab vedotin in combination with immunochemotherapy in patients with previously untreated diffuse large B-cell lymphoma: an open-label, non-randomised, phase 1b-2 study. Lancet Oncol 2019;20(7):998–1010. Epub 2019/05/19. doi: 10.1016/S1470-2045(19)30091–9. PubMed PMID: 31101489.Ethics ApprovalAll animal studies were conducted in accordance with protocols reviewed and approved by the Institutional Animal Care and Use Committee at Seagen or the external testing facility that conducted the studies.

Use of an antibody-drug conjugate targeting tissue factor to induce complete tumor regression in xenograft models with heterogeneous target expression.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 3066-3066 ◽  
Author(s):  
Esther CW Breij ◽  
David Satijn ◽  
Sandra Verploegen ◽  
Bart de Goeij ◽  
Danita Schuurhuis ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Tumor Cells ◽  
Tumor Regression ◽  
Antibody Drug Conjugate ◽  
Xenograft Models ◽  
Anti Tumor Activity ◽  
Complete Tumor ◽  
Antibody Drug

3066 Background: Tissue factor (TF) is the main initiator of coagulation, that starts when circulating factor VII(a) (FVII(a)) binds membrane bound TF. In addition, the TF:FVIIa complex can initiate a pro-angiogenic signaling pathway by activation of PAR-2. TF is aberrantly expressed in many solid tumors, and expression has been associated with poor prognosis. TF-011-vcMMAE, an antibody-drug conjugate (ADC) under development for the treatment of solid tumors, is composed of a human TF specific antibody (TF-011), a proteaseEcleavable valine-citrulline (vc) linker and the microtubule disrupting agent monomethyl auristatin E (MMAE). Methods: TF-011 and TF-011-vcMMAE were functionally characterized using in vitro assays. In vivo anti-tumor activity of TF-011-vcMMAE was assessed in human biopsy derived xenograft models, which genetically and histologically resemble human tumors. TF expression in xenografts was assessed using immunohistochemistry. Results: TF-011 inhibited TF:FVIIa induced intracellular signaling and efficiently killed tumor cells by antibody dependent cell-mediated cytoxicity in vitro, but showed only minor inhibition of TF procoagulant activity. TF-011 was rapidly internalized and targeted to the lysosomes, a prerequisite for intracellular MMAE release and subsequent tumor cell killing by the ADC. Indeed, TF-011-vcMMAE efficiently and specifically killed TF-positive tumors in vitro and in vivo. Importantly, TF-011-vcMMAE showed excellent anti-tumor activity in human biopsyEderived xenograft models derived from bladder, lung, pancreas, prostate, ovarian and cervical cancer (n=7). TF expression in these models was heterogeneous, ranging from 25-100% of tumor cells. Complete tumor regression was observed in all models, including cervical and ovarian cancer xenografts that showed only 25-50% TF positive tumor cells. Conclusions: TF-011-vcMMAE is a promising new ADC with potent anti-tumor activity in xenograft models that represent the heterogeneity of human tumors, including heterogeneous TF expression. The functional characteristics of TF-011-vcMMAE allow efficient tumor targeting, with minimal impact on coagulation.

scholarly journals A Small Molecule Antagonist of PD-1/PD-L1 Interactions Acts as an Immune Checkpoint Inhibitor for NSCLC and Melanoma Immunotherapy

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuanyuan Wang ◽  
Tingxuan Gu ◽  
Xueli Tian ◽  
Wenwen Li ◽  
Ran Zhao ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Monoclonal Antibodies ◽  
Small Molecule ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitor ◽  
Checkpoint Inhibitor ◽  
Small Molecule Antagonist ◽  
Programmed Death

Immune checkpoint inhibitors, such as monoclonal antibodies targeting programmed death 1 (PD-1) and programmed death ligand-1 (PD-L1), have achieved enormous success in the treatment of several cancers. However, monoclonal antibodies are expensive to produce, have poor tumor penetration, and may induce autoimmune side effects, all of which limit their application. Here, we demonstrate that PDI-1 (also name PD1/PD-L1 inhibitor 1), a small molecule antagonist of PD-1/PD-L1 interactions, shows potent anti-tumor activity in vitro and in vivo and acts by relieving PD-1/PD-L1-induced T cell exhaustion. We show that PDI-1 binds with high affinity to purified human and mouse PD-1 and PD-L1 proteins and is a competitive inhibitor of human PD-1/PD-L1 binding in vitro. Incubation of ex vivo activated human T cells with PDI-1 enhanced their cytotoxicity towards human lung cancer and melanoma cells, and concomitantly increased the production of granzyme B, perforin, and inflammatory cytokines. Luciferase reporter assays showed that PDI-1 directly increases TCR-mediated activation of NFAT in a PD-1/PD-L1-dependent manner. In two syngeneic mouse tumor models, the intraperitoneal administration of PDI-1 reduced the growth of tumors derived from human PD-L1-transfected mouse lung cancer and melanoma cells; increased and decreased the abundance of tumor-infiltrating CD8+ and FoxP3+ CD4+ T cells, respectively; decreased the abundance of PD-L1-expressing tumor cells, and increased the production of inflammatory cytokines. The anti-tumor effect of PDI-1 in vivo was comparable to that of the anti-PD-L1 antibody atezolizumab. These results suggest that the small molecule inhibitors of PD-1/PD-L1 may be effective as an alternative or complementary immune checkpoint inhibitor to monoclonal antibodies.

scholarly journals Engineered Erythrocytes As an Anti-Tumor Therapy through Induction of Apoptosis or Immune-Checkpoint Inhibition

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2166-2166
Author(s):  
Sivan Elloul ◽  
Claire Depew ◽  
Sujata Nerle ◽  
Tiffany Chen ◽  
Samuel Kaplan ◽  
...  
Keyword(s):  
Immune Checkpoint ◽  
Cell Lymphoma ◽  
Target Cells ◽  
Specific Cell ◽  
Red Cell ◽  
Checkpoint Inhibition ◽  
Employment Equity ◽  
Equity Ownership

Abstract Rubius Therapeutics has built a platform for producing allogeneic Red Cell Therapeutics (RCTs), genetically modified red blood cells expanded ex vivo. RCTs maintain the expected properties of normal RBCs including immunoprivilege, long circulating half life and deformability. Using lentiviral gene delivery, RCTs are able to harbor active intracellular as well as extracellular proteins, ranging from enzymes and cell targeting moieties to agonists and antibodies. RCTs represent a potentially transformational oncology platform, enabling multiple distinct modalities including tumor starvation, enhanced apoptotic signaling, and immune checkpoint inhibition, among others. The unique properties of the RCTs, including high avidity, the ability to express different moieties on and in the same cell, immunoprivilige, and extended T1/2 suggest that this platform represents the next generation of circulating cell-based therapeutics. Herein data is presented demonstrating how RCTs can be designed to target and engage specific cell types and mediate biological effects on these target cells. First, RCTs were tested for how effectively they bind to a known cell surface marker with therapeutic relevance, and whether a subsequent biological effect could be induced. We generated RCTs expressing an anti-CD20 single chain variable fragment on their surface (RCT-antiCD20) and assessed their ability to bind CD20+ lymphoma cells in vitro. We demonstrated efficient and specific binding of RCT-antiCD20 to target cells using flow cytometry and immunofluorescent microscopy. We further assessed whether this interaction could induce apoptosis by co-culturing RCT-antiCD20 cells with a panel of CD20+ human lymphoma cell lines, representing a variety of lymphoma subtypes; DoHH2 (follicular lymphoma), Ramos (Burkitt's lymphoma), Granta-519 (Mantle Cell Lymphoma) and SU-DHL-4 (diffuse large B cell lymphoma). In all cases, RCT-antiCD20 co-culture resulted in increased apoptosis relative to RCT or soluble Rituximab monoclonal antibody alone. Direct tumor cell killing in vitro was hypothesized to be more effective than monoclonal antibody alone due to the hyper-crosslinking of CD20 on the lymphoma cell. This effect was shown both by in situ demonstration of receptor clustering and by a stimulation of apoptotic pathways. Importantly, in an in vivo biodistribution study RCT-antiCD20 demonstrated strong and specific tumor pentration. These findings therefore demonstrate a novel biology for proteins expressed on RCTs and warranted testing for impact on lymphoma tumors in vivo, with lymphoma xenograft studies currently ongoing. Separately, we generated RCTs expressing on their surface antibodies against PD-1 and PD-L1 (RCT-antiPD-1 and RCT-antiPD-L1) to assess whether these RCTs could bind their respective targets and activate a robust immune response. Binding of RCT-antiPD-1 and RCT-antiPD-L1 to recombinant PD-1 and PD-L1, respectively was determined using flow cytometry. Functional activity was tested using an in vitro Jurkat cell IL-2 secretion assay. In this assay, IL-2 secretion is inhibited by incubating Jurkat cells with NHL cells (Z138) expressing PD-L1 upon stimulation with CD3/CD28 tetramers. We demonstrated that IL-2 secretion was rescued by culturing the Jurkat and Z138 cells with RCT-antiPD-1 or RCT-antiPD-L1, and not control RCT. The ability of these engineered RCTs to elicit activation was tested in a standard antigen recall assay. A robust 4-6 fold increase was demonstrated in interferon-gamma secretion of PBMC in an antigen recall assay, when co-cultured with RCT-antiPD-1 or RCT-antiPD-L1, in comparison to control PBMCs or control RCT alone. In conclusion, by using the Rubius platform for creating Red Cell Therapeutics, we were able to demonstrate that RCTs are capable of 1) engaging in specific cell-cell interactions and 2) inducing direct killing of NHL cells and 3) immune checkpoint engagement. Further studies are underway to evaluate the ability of these and other RCTs to access and kill tumor cells in vitro and in vivo. Our data support the development of RCTs as a novel class of therapeutic, enabling multiple modalities and mechanisms applicable to oncology and other indications. Disclosures Elloul: Rubius Therapeutics: Employment. Depew:Rubius Therapeutics: Employment. Nerle:Rubius Therapeutics: Employment. Chen:Rubius Therapeutics: Employment. Kaplan:Rubius Therapeutics: Employment. Dowden:Rubius Therapeutics: Employment, Equity Ownership. Mata-Fink:Rubius Therapeutics: Employment. Kahvejian:Rubius Therapeutics: Employment, Equity Ownership. Deans:Rubius Therapeutics: Employment, Equity Ownership.

TSP-A74, a Novel Therapeutic Monoclonal Antibody Against TfR1 for Treatment of Hematologic Malignancies

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5214-5214
Author(s):  
Lilin Zhang ◽  
Fumiko Nomura ◽  
Youichi Aikawa ◽  
Yukio Sudo ◽  
Kazuhiro Morishita ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Tumor Growth ◽  
Cell Lymphoma ◽  
Xenograft Model ◽  
Hematologic Malignancies ◽  
Tumor Growth Inhibition ◽  
Xenograft Models ◽  
Complete Tumor

Abstract Transferrin receptor 1(TfR1) is a type II transmembrane glycoprotein regulating the intracellular uptake of iron and is involved in cell growth, proliferation and survival. TfR1 is highly expressed on malignant cells, including those of hematologic malignancies. Therefore, TfR1 may be an attractive target for therapeutic monoclonal antibodies. We generated a panel of fully-human, anti-TfR1 monoclonal antibodies and evaluated the anti-tumor effects of these antibodies both in vitro and in vivo. The results led to the selection of TSP-A74, an antibody with potent in vitro and in vivo anti-tumor activity, for further evaluation in several hematologic malignancy models. First, the efficacy of TSP-A74 was evaluated in acute myeloid leukemia (AML) models. Two AML cell lines, Kasumi-1 and HL-60, were subcutaneously inoculated in severe combined immunodeficiency (SCID) mice. After the tumors were grown to a size of 150 mm3, TSP-A74 was administrated intravenously (IV) once weekly for 4 weeks at doses of 0.4, 2 and 10 mg/kg and 1, 3 and 10 mg/kg for the Kasumi and HL60 xenograft models, respectively. TSP-A74 demonstrated complete tumor regression in these two xenograft models at 10 mg/kg and complete tumor growth suppression in the Kasumi model at 2 mg/kg. Even at the low dose of 1 mg/kg, TSP-A74 demonstrated tumor growth inhibition (TGI) of 60% in the HL60 model. Next, the anti-tumor efficacy of TSP-A74 was assessed in an acute lymphoblastic leukemia (ALL) model. The ALL cell line, CCRF-CEM, was engrafted into SCID mice intravenously. After 3 days, TSP-A74 was administrated IV at a dose of 10 mg/kg once weekly for 4 weeks. The control mice (n=10) rapidly developed leukemia and none survived at 42 days after leukemia cell engraftment. However, 7 of 10 (70%) mice treated with TSP-A74 survived to 179 days after engraftment when the study was terminated. Finally, the efficacy of TSP-A74 was evaluated in non-Hodgkin's lymphoma subcutaneous xenograft models. TSP-A74 produced complete regression of established tumors in the SU-DHL-2 (diffuse large B-cell lymphoma) xenograft model at a dose of 3 mg/kg and tumor growth inhibition of 100 % in the HH (cutaneous T cell lymphoma) xenograft model at a dose of 10 mg/kg. These results indicate that the human anti-TfR1 monoclonal antibody, TSP-A74, could be a new therapeutic candidate for hematologic malignancies. Disclosures Zhang: Perseus Proteomics Inc.: Employment. Nomura:Perseus Proteomics Inc.: Employment. Aikawa:Perseus Proteomics Inc.: Employment. Sudo:Perseus Proteomics Inc.: Employment. Morishita:Perseus Proteomics Inc.: Research Funding.

scholarly journals The Expression and Effect of B7-H3 in Mantle Cell Lymphoma

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4811-4811
Author(s):  
Jing Wang ◽  
Wei Zhang ◽  
Yanfang Wang ◽  
Fei Dong ◽  
Mingxia Zhu ◽  
...  
Keyword(s):  
Mantle Cell Lymphoma ◽  
Caspase 3 ◽  
Cell Lymphoma ◽  
Ki 67 ◽  
Chemotherapy Drugs ◽  
Mantle Cell ◽  
Xenograft Models ◽  
Related Proteins

Abstract Objective : To investigate the effects of B7-H3 (CD276) on oncogenesis and chemosensitivity in mantle cell lymphoma (MCL). Methods : The B7-H3 expression was detected by flow cytometry in cell lines, 20 patients with MCL and 20 volunteers. B7-H3 knockdown was performed using lentivirus transduction in the Maver and Z138 mantle cell lymphoma cell lines, respectively. The effects of B7-H3 on cell proliferation, cycle, migration and invasion were investigated by CCK-8 assay, methyl cellulose colony forming assay, PI staining, and Transwell assays in vitro. By establishing Maver and Z138 xenograft models, the effects of B7-H3 on tumourigenicity were observed, and Ki-67 and PCNA was detected through immunohistochemical. Moreover, the impacts of B7-H3 RNAi on the anti-tumor effect of chemotherapy drugs were determined with CCK-8, Annexin V-FITC/PI and Hoechst 33342 staining assays in vitro and with xenograft models in vivo. Results: The frequency of B7-H3positive expression cases was 65.0% (13/20) in MCL patients and 10.0% (2/20) in volunteers. The down-regulation of B7-H3 significantly decreased tumor proliferation in MCL in vitro and in vivo. In the B7-H3 knockdown groups of Maver and Z138 xenograft models, the mean inhibition rate of tumor growth was 59.1% and 65.0% (p = 0.010 and 0.003), and the expression of both Ki-67 and PCNA were significantly lower, respectively. After B7-H3 silencing, the cell cycles of Maver and Z138 were both arrested at G0/G1 phase, and the expression of cell cycle-related proteins Cyclin D1 and CDK4 was lower. The cell migration rates and invasion capacity were decreased, and the rates of distant metastasis in B7-H3 knockdown both Maver and Z138 xenografts were significantly declined as well. The expression of invasion-related proteins MMP-2 and MMP-9 was lower in B7-H3 knockdown cells and xenografts. The silencing of B7-H3 increased the sensitivity of Maver and Z138 cells to Rituximab and Bendamustine and enhanced the drug-induced apoptosis, respectively. The activity of caspase-3 in vitro and the expression of caspase-3 in both Maver and Z138 xenografts was significantly increased in the B7-H3 shRNA combined with chemotherapy drugs groups. Conclusions: B7-H3 levels in MCL patients were signifiantly higher than that in volunteers. Our study demonstrates for the first time that B7-H3 promotes mantle cell lymphoma progression and B7-H3 knockdown significantly enhances the chemosensitivity. This may provide a new therapeutic approach to mantle cell lymphoma. Disclosures No relevant conflicts of interest to declare.

HCD122, an Antagonist Human Anti-CD40 Monoclonal Antibody, Inhibits Tumor Growth in Xenograft Models of Human Diffuse Large B-Cell Lymphoma, a Subset of Non-Hodgkins Lymphoma.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2519-2519 ◽  
Author(s):  
Ssucheng J. Hsu ◽  
Lin A. Esposito ◽  
Sharon L. Aukerman ◽  
Seema Kantak ◽  
Amer M. Mirza
Keyword(s):  
Tumor Growth ◽  
B Cell ◽  
Cell Lymphoma ◽  
Single Agent ◽  
B Cell Lymphoma ◽  
Large B Cell Lymphoma ◽  
Non Hodgkins Lymphoma ◽  
Xenograft Models

Abstract CD40, a member of the tumor necrosis factor receptor family, is expressed in all human B-cell malignancies and engagement by the CD40 ligand (CD40L) is important for both cell proliferation and cell survival. CD40L has been shown to be co-expressed with CD40 in neoplastic B-cells from Chronic Lymphocytic Leukemia (CLL) and Non-Hodgkins Lymphoma (NHL), suggesting the importance of an autocrine CD40/CD40L loop in these malignancies. HCD122 (formerly known as CHIR-12.12) is a fully human, highly potent, IgG1 antagonist anti-CD40 monoclonal antibody (mAb) that blocks CD40/CD40L interactions in vitro and also mediates ADCC. Previous studies showed that HCD122 can mediate ADCC in vitro and has anti-proliferative and anti-tumor activities as a single agent in CLL, MM, and Burkitts Lymphoma in vitro and in vivo. In this study, the activity of HCD122 on a subtype of NHL, Diffuse Large B-Cell Lymphoma (DLBCL) was examined. The DLBCL derived cell lines, RL and SU-DHL-4, were selected for this study based upon in vivo characterization as well as their sensitivity to Rituximab as reported in the literature. These cell lines were subsequently confirmed for the expression of CD40 and CD20 by flow cytometry. The in vivo anti-tumor effects of HCD122 as single agent was demonstrated in these two xenograft models and was compared to Rituximab, an anti-CD20 antibody therapeutic currently approved for the treatment of relapsed or refractory, low-grade or follicular, NHL. HCD122 when administered intraperitoneally weekly at 1 mg/kg significantly reduced tumor growth with a tumor growth inhibition (TGI) of 85.5% (P<0.01) in the RL model. At the same dose and schedule in the RL model, TGI achieved with Rituximab was 31.7% (P>0.05). In the SU-DHL-4 model, an 85% TGI (P<0.01) was observed at the 1 mg/kg dose of HCD122. In comparison, Rituximab at this dose elicited a 57.6% TGI (P<0.05). Additionally, the downstream CD40/CD40L signal transduction pathways were also examined in order to elucidate the molecular mechanism underlying the HCD122-mediated effects in DLBCL. Taken together, these results support the clinical development of HCD122 for the treatment of DLBCL. Currently HCD122 is in Phase I trials for treatment of CLL and MM.

scholarly journals Bio-Inspired Functional Lipoprotein-like Nanoparticles (Flip-NPs) Cause Cholesterol Starvation and Ferroptosis in B-Cell Lymphomas: Studies in Cell Lines, Xenograft Models and Primary Patient Samples

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2857-2857
Author(s):  
Jonathan Rink ◽  
Adam Yuh Lin ◽  
Shuo Yang ◽  
Amir Behdad ◽  
Reem Karmali ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Death ◽  
B Cell ◽  
Cell Lines ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Cholesterol Reduction ◽  
Xenograft Models

Introduction: Hematologic malignancies, including B cell lymphomas such as diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL), have increased demands for cholesterol and cholesteryl esters to maintain membrane anchored pro-proliferative and pro-survival signaling pathways, including B cell receptor signaling. Recent evidence suggests that certain cancer cell lines, including several anaplastic large T cell lymphoma (ALCL) cell lines, are auxotrophic for cholesterol and are sensitive to cholesterol reduction-induced ferroptosis (Garcia-Bermudez, Nature 2019), an iron dependent form of programmed cell death characterized by accumulation of lipid peroxides. We have developed a cholesterol depleting functional lipoprotein-like nanoparticle (Flip-NP) that specifically targets the high-affinity HDL receptor, scavenger receptor type B1 (SCARB1), which maintains cellular and cell membrane cholesterol homeostasis. Our prior data demonstrated that Flip-NPs induce B cell lymphoma cell death in vitro and in in vivo xenograft models. Accordingly, we hypothesized that the mechanism of cell death by Flip-NPs in B cell lymphomas is ferroptosis, and that Flip-NPs would be potent therapy for an expanded number of cholesterol-addicted malignancies, including ALCL. Methods: After informed consent, primary B cell lymphoma cells were isolated from excisional biopsies from patients with FL or DLBCL. The SUDHL4 [germinal center (GC) DLBCL], Ramos [Burkitt's lymphoma], SUDHL1 [ALCL] and SR-786 [ALCL] cell lines were used for in vitro experiments. SCARB1 expression was quantified using flow cytometry and western blot analysis. Cell viability was quantified using the MTS assay and flow cytometry. Ferroptosis was measured using the lipophilic antioxidant ferrostatin-1 or the iron chelator deferoxamine. Gene expression changes were quantified using RT-qPCR. Lipid peroxidation was measured using C11-BODIPY and flow cytometry. SUDHL1 and SUDHL4 flank tumor xenografts were initiated in SCID-beige mice, with Flip-NPs administered 3 times per week IV. Results: Primary B cell lymphoma cells were isolated from patients with FL (n=4) or DLBCL (n=2), and all samples expressed some level of SCARB1 by flow cytometry. Flip-NPs increased cell death in 3 of the 4 FL samples and 1 of 2 DLBCL samples. In Ramos and SUDHL4 cells, RT-qPCR data showed that Flip-NP-mediated cholesterol reduction led to up-regulation of cholesterol biosynthesis genes and down-regulation of glutathione peroxidase-4 (GPX4), a critical protein responsible for degradation of lipid peroxides. Correspondingly, as shown with C11-BODIPY, Flip-NP treatment increased lipid peroxide accumulation in Ramos and SUDHL4 cells. Addition of ferrostatin-1 or deferoxamine reduced Flip-NP induced cell death, demonstrating that the mechanism-of-action of Flip-NPs involves, at least in part, ferroptosis. Given the sensitivity of cholesterol auxotrophic cell lines to cholesterol reduction-induced ferroptosis, we tested the efficacy of the Flip-NPs against cholesterol auxotrophic ALK+ ALCL cell lines SUDHL1 and SR-786. SCARB1 was expressed in both cell lines. Flip-NPs potently induced cell death in both SUDHL1 and SR-786 cells in vitro. In vivo, systemic administration of Flip-NPs reduced tumor volumes in both SUDHL4 and SUDHL1 tumor xenograft models. Conclusions: Our data show that Flip-NPs reduce GPX4 expression and increase lipid peroxide accumulation in B cell lymphoma cell lines, resulting in ferroptosis. Expanding on these results, Flip-NP efficacy was also demonstrated in cholesterol auxotrophic ALK+ ALCL cell lines and primary patient-derived B cell lymphoma cells. These in vitro results translated to in vivo murine models, as systemic administration of Flip-NPs potently reduced DLBCL and ALK+ ALCL tumor xenograft burden. Flip-NPs are a molecularly targeted, first-in-class therapy that may be effective for malignancies reliant upon cellular cholesterol. Disclosures Behdad: Pfizer: Other: Speaker; Thermo Fisher: Membership on an entity's Board of Directors or advisory committees; Loxo-Bayer: Membership on an entity's Board of Directors or advisory committees. Karmali:Astrazeneca: Speakers Bureau; Takeda, BMS: Other: Research Funding to Institution; Gilead/Kite; Juno/Celgene: Consultancy, Speakers Bureau. Thaxton:Zylem: Other: Co-founder of the biotech company Zylem. Gordon:Juno/Celgene: Other: Advisory Board, Research Funding; Gilead: Other: Advisory Board; Bayer: Other: Advisory Board; Zylem LLC: Other: co-founder; research in nanoparticles in cancer.

scholarly journals The BET Inhibitor JQ1 Augments the Antitumor Efficacy of Gemcitabine in Preclinical Models of Pancreatic Cancer

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3470
Author(s):  
Aubrey L. Miller ◽  
Patrick L. Garcia ◽  
Samuel C. Fehling ◽  
Tracy L. Gamblin ◽  
Rebecca B. Vance ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Dna Damage ◽  
Cholesterol Biosynthesis ◽  
Antitumor Efficacy ◽  
Rna Seq ◽  
Bet Inhibitor ◽  
Bet Inhibitors ◽  
Xenograft Models

Gemcitabine is used to treat pancreatic cancer (PC), but is not curative. We sought to determine whether gemcitabine + a BET bromodomain inhibitor was superior to gemcitabine, and identify proteins that may contribute to the efficacy of this combination. This study was based on observations that cell cycle dysregulation and DNA damage augment the efficacy of gemcitabine. BET inhibitors arrest cells in G1 and allow increases in DNA damage, likely due to inhibition of expression of DNA repair proteins Ku80 and RAD51. BET inhibitors (JQ1 or I-BET762) + gemcitabine were synergistic in vitro, in Panc1, MiaPaCa2 and Su86 PC cell lines. JQ1 + gemcitabine was more effective in vivo than either drug alone in patient-derived xenograft models (P < 0.01). Increases in the apoptosis marker cleaved caspase 3 and DNA damage marker γH2AX paralleled antitumor efficacy. Notably, RNA-seq data showed that JQ1 + gemcitabine selectively inhibited HMGCS2 and APOC1 ~6-fold, compared to controls. These proteins contribute to cholesterol biosynthesis and lipid metabolism, and their overexpression supports tumor cell proliferation. IPA data indicated that JQ1 + gemcitabine selectively inhibited the LXR/RXR activation pathway, suggesting the hypothesis that this inhibition may contribute to the observed in vivo efficacy of JQ1 + gemcitabine.

376 A phase I/II study of live biotherapeutic MRx0518 in combination with pembrolizumab in patients refractory to immune checkpoint inhibitors

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A401-A401
Author(s):  
Shubham Pant ◽  
Amishi Shah ◽  
Pavlos Msaouel ◽  
Matthew Campbell ◽  
Shi-Ming Tu ◽  
...  
Keyword(s):  
Phase I ◽  
Disease Progression ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Checkpoint Inhibitors ◽  
Tumour Response ◽  
Checkpoint Inhibition ◽  
Single Strain

BackgroundMRx0518 is a novel, human gut microbiome-derived, single-strain, oral live biotherapeutic. It is a bacterium of the Enterococcus genus that was selected for development in the treatment of solid tumours for its strong in vitro and in vivo immunostimulatory activity. In vivo studies have shown that MRx0518 can inhibit tumour growth in different syngeneic cancer models as monotherapy and in combination with checkpoint inhibitors. MRx0518 has been shown to reduce Treg and increase Th1 and Tc1 lymphocyte differentiation in vitro, and increase intratumoral CD4+ and CD8+ T cells and NK cells in vivo.This phase I/II clinical study is evaluating the combination of MRx0518 and pembrolizumab in a cohort of heavily pre-treated patients refractory to immune checkpoint inhibitors (ICIs) to assess whether it is safe and can provide a clinical benefit.MethodsThe study is being conducted in two parts. Part A is complete and evaluated safety of the combination therapy in a cohort of 12 mRCC and mNSCLC patients. This data was assessed by the Safety Review Committee and it was determined appropriate to proceed to Part B. Part B is now recruiting up to 30 additional patients per indication (RCC, NSCLC or bladder cancer) at several US sites. Patients in both parts must be refractory to checkpoint inhibition. This is defined as having had an initial benefit from PD-1 pathway targeting immune checkpoint inhibition (ICI) but developing disease progression confirmed by two radiological scans ≥4 weeks apart in the absence of rapid clinical progression and within 12 weeks of last dose of ICI. Patients are treated with 1 capsule of MRx0518 (1 × 1010 to 1 × 1011 CFU) twice daily and pembrolizumab (200 mg every 3 weeks) for up to 35 cycles or until disease progression. Tumour response is assessed every 9 weeks per RECIST. Blood, stool and urine samples are collected throughout the study to evaluate immune markers and microbiome. Patients may choose to consent to tissue biopsies. The primary objective of the study is to evaluate safety of the combination by monitoring toxicities in the first cycle of treatment. Secondary objectives are to evaluate efficacy via ORR, DOR, DCR (CR, PR or SD ≥6 months) and PFS. Exploratory objectives are to evaluate biomarkers of treatment effect, impact on microbiota and OS and correlation of clinical outcome with PD-L1 CPS/TPS.ResultsN/AConclusionsN/ATrial RegistrationNCT03637803Ethics ApprovalThis study was approved by University of Texas MD Anderson’s Institutional Review Board; approval ref. 2018-0290

Sign in / Sign up

Export Citation Format

Share Document