Combination Therapy with Novel Nanoparticle, SNS01-T, and Lenalidomide Triggers Synergistic Cytotoxicity in Vitro and in Vivo in Multiple Myeloma and Mantle Cell Lymphoma

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4223-4223
Author(s):  
Catherine A Taylor ◽  
Terence Tang ◽  
Zhongda Liu ◽  
Sarah Francis ◽  
Zheng Qifa ◽  
...  

Abstract Abstract 4223 SNS01-T is a novel nanoparticle that is designed to selectively initiate apoptosis in B-cell cancers such as multiple myeloma and B-cell lymphomas. SNS01-T is comprised of a plasmid encoding a pro-apoptotic form of the eukaryotic translation initiation factor 5A (eIF5A) containing a single-point mutation that prevents hypusination, an siRNA that inhibits expression of the pro-survival hypusine-eIF5A protein, and a polymer that serves to assemble the nucleic acids into a nanoparticle. SNS01-T is currently being investigated in a multi-site, open-label Phase1b/2a dose escalation study in subjects with relapsed or refractory multiple myeloma (MM). SNS01-T and its preclinical precursors have been studied extensively in multiple myeloma and B cell lymphoma tumor models. In this study we tested the in vitro and in vivo anti-cancer activity of SNS01-T in combination with the immunomodulatory drug lenalidomide. The combination of low doses of SNS01-T and lenalidomide synergistically reduced viability of RPMI 8226 MM cells and induced apoptosis to a greater degree than either drug alone. To determine whether SNS01-T treatment increases the anti-myeloma activity of lenalidomide in vivo, 0.375 mg/kg SNS01-T was combined with either 15 or 50 mg/kg lenalidomide in a RPMI 8226 xenograft model of multiple myeloma. Mice were dosed for two cycles of treatment for a total of 11 weeks of dosing. Mice with no measurable tumor at the end of the first cycle of treatment did not receive treatment in the second cycle but were monitored closely for tumor recurrence. A two-week observation period at the end of the study allowed monitoring of tumor growth after the cessation of the second cycle of treatment. At the end of the second cycle of dosing, tumor growth was inhibited by 84 % (p < 0.0001), 34 % (p = 0.05), and 98.1 % (p << 0.0001) in animals treated with SNS01-T, 50 mg/kg lenalidomide, and SNS01-T plus 50 mg/kg lenalidomide, respectively. Complete tumor regression (undetectable tumor) was achieved in 40% of mice treated with SNS01-T, 0% of mice treated with 50 mg/kg lenalidomide, and 83% of mice treated with the combination therapy of SNS01-T and 50 mg/kg lenalidomide. Complete regression of tumors treated with the combination therapy was maintained for more than 8 weeks without treatment until the end of the study in 4 of 6 (67%) of treated mice. Combining SNS01-T treatment with 50 mg/kg lenalidomide inhibited tumor growth more effectively than either drug alone and prolonged survival with 100% of mice surviving to the end of the 102-day study. Combination therapy with SNS01-T and 15 mg/kg lenalidomide also demonstrated significant activity in a murine JMV-2 mantle cell lymphoma (MCL) xenograft model. Treatment of mice with the drug combination of SNS01-T and lenalidomide resulted in a statistically significant increase in survival compared to either SNS01-T (p = 0.002; logrank test) or lenalidomide (p = 0.007) alone. Collectively, these preclinical studies indicate that the combination therapy of SNS01-T and lenalidomide is well tolerated, has significant activity against MM and MCL, and provides a strong rationale to evaluate SNS01-T and lenalidomide combination therapy to improve patient outcome in MM and B cell lymphomas. Disclosures: Taylor: Senesco Technologies Inc.: stock options Other. Dondero:Senesco Technologies Inc.: Employment. Thompson:Senesco Technologies Inc.: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1844-1844
Author(s):  
John Richards ◽  
Myriam N Bouchlaka ◽  
Robyn J Puro ◽  
Ben J Capoccia ◽  
Ronald R Hiebsch ◽  
...  

AO-176 is a highly differentiated, humanized anti-CD47 IgG2 antibody that is unique among agents in this class of checkpoint inhibitors. AO-176 works by blocking the "don't eat me" signal, the standard mechanism of anti-CD47 antibodies, but also by directly killing tumor cells. Importantly, AO-176 binds preferentially to tumor cells, compared to normal cells, and binds even more potently to tumors in their acidic microenvironment (low pH). Hematological neoplasms are the fourth most frequently diagnosed cancers in both men and women and account for approximately 10% of all cancers. Here we describe AO-176, a highly differentiated anti-CD47 antibody that potently targets hematologic cancers in vitro and in vivo. As a single agent, AO-176 not only promotes phagocytosis (15-45%, EC50 = 0.33-4.1 µg/ml) of hematologic tumor cell lines (acute myeloid leukemia, non-Hodgkin's lymphoma, multiple myeloma, and T cell leukemia) but also directly targets and kills tumor cells (18-46% Annexin V positivity, EC50 = 0.63-10 µg/ml) in a non-ADCC manner. In combination with agents targeting CD20 (rituximab) or CD38 (daratumumab), AO-176 mediates enhanced phagocytosis of lymphoma and multiple myeloma cell lines, respectively. In vivo, AO-176 mediates potent monotherapy tumor growth inhibition of hematologic tumors including Raji B cell lymphoma and RPMI-8226 multiple myeloma xenograft models in a dose-dependent manner. Concomitant with tumor growth inhibition, immune cell infiltrates were observed with elevated numbers of macrophage and dendritic cells, along with increased pro-inflammatory cytokine levels in AO-176 treated animals. When combined with bortezomib, AO-176 was able to elicit complete tumor regression (100% CR in 10/10 animals treated with either 10 or 25 mg/kg AO-176 + 1 mg/kg bortezomib) with no detectable tumor out to 100 days at study termination. Overall survival was also greatly improved following combination therapy compared to animals treated with bortezomib or AO-176 alone. These data show that AO-176 exhibits promising monotherapy and combination therapy activity, both in vitro and in vivo, against hematologic cancers. These findings also add to the previously reported anti-tumor efficacy exhibited by AO-176 in solid tumor xenografts representing ovarian, gastric and breast cancer. With AO-176's highly differentiated MOA and binding characteristics, it may have the potential to improve upon the safety and efficacy profiles relative to other agents in this class. AO-176 is currently being evaluated in a Phase 1 clinical trial (NCT03834948) for the treatment of patients with select solid tumors. Disclosures Richards: Arch Oncology Inc.: Employment, Equity Ownership, Other: Salary. Bouchlaka:Arch Oncology Inc.: Consultancy, Equity Ownership. Puro:Arch Oncology Inc.: Employment, Equity Ownership. Capoccia:Arch Oncology Inc.: Employment, Equity Ownership. Hiebsch:Arch Oncology Inc.: Employment, Equity Ownership. Donio:Arch Oncology Inc.: Employment, Equity Ownership. Wilson:Arch Oncology Inc.: Employment, Equity Ownership. Chakraborty:Arch Oncology Inc.: Employment, Equity Ownership. Sung:Arch Oncology Inc.: Employment, Equity Ownership. Pereira:Arch Oncology Inc.: Employment, Equity Ownership.


2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Ruosi Yao ◽  
Xiaoyang Sun ◽  
Yu Xie ◽  
Xiaoshen Sun ◽  
Yao Yao ◽  
...  

Increasing evidence shows that c-Myc oncoprotein is tightly associated with multiple myeloma (MM) progression. Herein, we identified compound 7594-0035, which is a novel inhibitor that specifically targets c-Myc. It was identified from the ChemDiv compound database by molecular docking-based, high-throughput virtual screening. Compound 7594-0035 inhibited MM cell proliferation in vitro, induced cell cycle G2-phase arrest, and triggered MM cell death by disturbing the stability of c-Myc protein. Additionally, we also found that compound 7594-0035 overcame bortezomib (BTZ) drug resistance and increased the killing effect on MM cells in combination with BTZ. The severe combined immune deficiency (SCID) mouse xenograft model revealed that compound 7594-0035 partially decreased the primary tumor growth of Roswell Park Memorial Institute (RPMI)-8226 cells in vivo. The novel small molecular compound 7594-0035 described in the present study that targets c-Myc protein is likely to be a promising therapeutic agent for relapsed/refractory MM.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3931-3931 ◽  
Author(s):  
Paul A. Algate ◽  
Jennifer Wiens ◽  
Christy Nilsson ◽  
Mien Sho ◽  
Debra T. Chao ◽  
...  

Abstract Abstract 3931 Background: CD37 is a 50–55 kDa heavily glycosylated member of the tetraspanin superfamily of molecules. This cell surface protein is expressed on normal and transformed B-cells, and has been implicated in diverse processes including cellular activation and proliferation, cell motility, and cell-cell adhesion. TRU-016 is a novel humanized anti-CD37 SMIP™ protein. Pre-clinical studies have demonstrated that anti-CD37 SMIP™ protein mediates caspase-independent direct killing of normal and malignant B-cells, a mechanism of action that appears to be different than CD20 therapies. In addition, TRU-016 results in indirect killing through NK cell mediated SMIP-protein directed cellular cytotoxicity (SDCC). The therapeutic potential of TRU-016 against several subsets of B-cell malignancies is currently being investigated in the clinic. Methods: The ability of TRU-016 to interact and increase cell killing with established therapeutics rituximab (anti-CD20 antibody), bendamustine (bi-functional alkylating agent/nucleoside analog), LY294002 (PI3K inhibitor) and temsirolimus (mTOR inhibitor) was investigated in vitro using the Rec-1 (mantle cell lymphoma) and SU-DHL-6 (diffuse large B cell lymphoma) cell lines. Individual drugs were tested in combination with TRU-016 as well as in a multiple drug cocktail. Combination index analyses were performed for drug combinations over the 20–90% effect levels. To determine whether in vitro synergy could be recapitulated in vivo, DoHH-2 (follicular lymphoma) xenografts were treated with TRU-016, bendamustine, and the combination of TRU-016 and bendamustine with or without rituximab. Furthermore, the effect of the dosing schedule with the combination of TRU-016 and rituximab was explored by comparing the treatment over a short time period to an extended (maintenance) dosing regimen. CD37 expression on the tumor xenografts was evaluated post different treatment by immunohistochemistry. Results: Combination index analyses determined that the killing effects of TRU-016 was synergistic with rituximab, bendamustine and temsirolimus in NHL models. Furthermore, TRU-016 provided additional efficacy when added to the combination of rituximab and bendamustine. In vivo results demonstrated that the in vitro synergy results were applicable to a more complex in vivo disease model. The combination of TRU-016 with bendamustine or rituximab resulted in increased tumor growth delay compared to that attained with the individual drugs. The addition of TRU-016 to the combination of bendamustine and rituximab resulted in increased tumor growth delay compared to the two drugs alone. The observed efficacy of the combination of TRU-016 and rituximab could be extended with repeated (maintenance) dosing with tumor free survival being observed beyond the 35 days of dosing. The combination of TRU-016 with temsirolimus also resulted in a reduction of tumor growth compared to either molecule alone. CD37 target expression was detected in the xenograft tumors post-treatment with all drugs tested. Conclusions: TRU-016 in combination with rituximab, bendamustine or temsirolimus increased cell killing of NHL cells in vitro over that observed for each agent alone. Furthermore, the triple combination of TRU-016 with rituximab, bendamustine or temsirolimus displayed greater anti-tumor activity in vivo than each of the agents alone against a follicular lymphoma tumor model. The addition of TRU-016 to a combination of rituximab and bendamustine resulted in increased killing in vitro and in vivo. The combinatorial activity of TRU-016 and rituximab in vivo was increased when the drugs were administered over a longer period. These results provide preclinical rationale for the potential different combinations of TRU-016 with several established therapeutics for the treatment of NHL and related B-cell malignancies. Disclosures: Algate: Trubion Pharmaceuticals: Employment. Wiens:Trubion Pharmaceuticals: Employment. Nilsson:Trubion Pharmaceuticals: Employment. Sho:Facet/Abbott: Employment. Chao:Facet/Abbott: Employment. Starling:Facet/Abbott: Employment. Gordon:Trubion Pharmaceuticals: Employment.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 880-880
Author(s):  
Catherine A Taylor ◽  
Terence Tang ◽  
Sarah Francis ◽  
Zhongda Liu ◽  
Qifa Zheng ◽  
...  

Abstract SNS01-T is a novel nanoparticle that is designed to selectively initiate apoptosis in B-cell cancers such as multiple myeloma and non-Hodgkins B-cell lymphomas. SNS01-T comprises a plasmid DNA (pExp5A) encoding a pro-apoptotic form of the eukaryotic translation initiation factor 5A (eIF5A) containing a single-point mutation that prevents hypusination, an eIF5A siRNA that inhibits expression of the pro-survival hypusine-eIF5A protein, and a polymer that serves to assemble the nucleic acids into a nanoparticle. SNS01-T is currently being investigated in a multi-site, open-label Phase1b/2a dose escalation study in subjects with relapsed or refractory multiple myeloma (MM), mantle cell lymphoma (MCL), or diffuse large B cell lymphoma (DLBCL). SNS01-T has demonstrated activity in MM xenograft models as well as in B cell lymphoma models of MCL and DLBCL, when administered twice weekly at doses ≥ 0.18 mg(nucleic acid)/kg. In this study we compared the ability of SNS01-T to transfect, regulate eIF5A expression, and kill MM, DLBCL, and MCL cell lines. Furthermore, the activity of SNS01-T in normal B cells was investigated. A previous study using a KAS-6/1 MM xenograft model demonstrated that the eIF5A siRNA and plasmid pExp5A both have anti-tumoral activity in MM but had a greater impact on tumour growth when combined together as SNS01-T. This finding was confirmed in this study in a second MM model (RPMI 8226) as well as in a DLBCL xenograft model. To determine the efficiency of SNS01-T transfection into malignant or normal B cells, the pExp5A plasmid and eIF5A siRNA were labeled with FITC and DY547, respectively, packaged into nanoparticles using polyethylenimine polymer, and used to transfect cultured cells. FACS analysis was used to determine the percent of the cell population transfected with plasmid, siRNA, or both. RT-qPCR was used to assess biological activity of SNS01-T by quantifying the expression of eIF5AK50R mRNA transgene and endogenous eIF5A mRNA in a variety of B cell lines. The IC50 of SNS01-T in a panel of MM, MCL, and DLBCL cell lines was determined by XTT assay. SCID mice bearing either RPMI 8226 MM tumours or SuDHL6 GCB DLBCL tumours were treated with pExp5A plasmid (formulated with PEI and control siRNA), eIF5A siRNA (formulated with PEI and a control plasmid), or SNS01-T at 0.375 mg/kg twice per week by intravenous injection. SNS01-T was able to transfect MM, MCL, and DLBCL cell lines, although the proportion of cells transfected with both plasmid and siRNA was higher in MM cells. Transfection of SNS01-T resulted in expression of the transgene as well as a statistically significant reduction in expression of eIF5A mRNA compared to untreated controls for all three cell types. In contrast, normal B cells were found to take up fluorescently-labeled SNS01-T with reduced efficiency compared to RPMI 8226 MM cells. Futhermore, SNS01-T was observed to induce cell death in RPMI 8226 MM cells but not in normal B cells. In the RPMI 8226 xenograft model, treatment with either the pExp5A plasmid alone or eIF5A siRNA alone resulted in a 66 % reduction (p < 0.0001) or 44 % reduction (p < 0.05) in tumor volume compared to the control group at day 24 of the study. In contrast, treatment with SNS01-T, which contains both the pExp5A plasmid and the eIF5A siRNA, resulted in an 86 % (p < 0.0001) reduction in tumor volume. A similar result was observed in the SuDHL6 model with a 14 % reduction or 27 % reduction (p < 0.05) in tumor volume compared to the control group at day 20 of the study following treatment with pExp5A plasmid or eIF5A siRNA, respectively. In contrast, treatment with SNS01-T resulted in a 79 % (p < 0.0001) reduction in tumor volume. Collectively, these preclinical studies indicate that SNS01-T therapy has significant potential against MM, MCL, and DLBCL. Disclosures: Taylor: Senesco Technologies: stock options Other. Dondero:Senesco Technologies: Employment. Thompson:Senesco Technologies: Consultancy, Equity Ownership, Membership on an entity’s Board of Directors or advisory committees, Research Funding.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 699-699 ◽  
Author(s):  
Hsu-Ping Kuo ◽  
Sidney Hsieh ◽  
Karl J. Schweighofer ◽  
Leo WK Cheung ◽  
Shiquan Wu ◽  
...  

Abstract Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma (NHL), accounting for roughly 30% of newly diagnosed cases in the United States (US). DLBCL is a heterogeneous lymphoma, including the activated B cell-like (ABC) and germinal center B cell-like (GCB) subtypes, which have different gene expression profiles, oncogenic aberrations, and clinical outcomes (Alizadeh, Nature 2000; Staudt, Adv Immunol 2005). ABC-DLBCL is characterized by chronic active B-cell receptor (BCR) signaling (Davis, Nature 2010), which is required for cell survival. Thus, the BCR signaling pathway is an attractive therapeutic target in this type of B-cell malignancy. Bruton's tyrosine kinase (BTK), which plays a pivotal role in BCR signaling, is covalently bound with high affinity by ibrutinib, a first-in-class BTK inhibitor approved in the US for mantle cell lymphoma and chronic lymphocytic leukemia (CLL) patients (pts) who have received at least one prior treatment, CLL with del17p, and WaldenstršmÕs macroglobulinemia. A recent phase 2 clinical trial of single-agent ibrutinib in DLBCL pts revealed an overall response rate of 40% for ABC-DLBCL (Wilson, Nat. Med 2015); however, responses to single kinase-targeted cancer therapies are often limited by the cellÕs ability to bypass the target via alternative pathways or acquired mutations in the target or its pathway (Nardi, Curr Opin Hematol 2004; Gazdar, Oncogene 2009). The serine/threonine-protein kinase PIM1 is one of several genes exhibiting differential expression in ibrutinib-resistant ABC-DLBCL cells compared with wild-type (WT) cells. We identified and report herein the role of PIM1 in ABC-DLBCL ibrutinib-resistant cells. Methods: PIM1 gene expression was analyzed by RT-qPCR. In vitro, cell viability was assessed in the human ABC-DLBCL cell line HBL-1 after treatment with ibrutinib and/or a pan-PIM inhibitor for 3 days, and the effect on colony formation was determined 7 days post-treatment. PIM1 mutational analysis was performed with clinical tumor biopsy samples from 2 studies, PCYC-04753 (NCT00849654) and PCYC-1106-CA (NCT01325701). PIM1 protein stability was analyzed by treating cells with cycloheximide and examining protein levels at different time points up to 8 hours. Results: Gene expression profiling of ibrutinib-resistant ABC-DLBCL cells revealed an upregulation of PIM1 (15-fold increase compared with WT cells) as well as PIM2 and PIM3. We also found that, compared with single-drug treatment, in vitro cell growth could be synergistically suppressed with a combination of ibrutinib and a pan-PIM inhibitor. This effect was observed in both WT (combination index (C.I.) = 0.25; synergy score = 3.18) and ibrutinib-resistant HBL-1 cells (C.I. = 0.18; synergy score = 4.98). In HBL-1 cells, this drug combination reduced colony formation and suppressed tumor growth in a xenograft model (Figure 1). In 48 DLBCL patient samples with available genomic profiling, PIM1 mutations appeared more frequently in pts diagnosed with ABC-DLBCL compared with GCB-DLBCL (5 out of 6 DLBCL pts with PIM1 mutations were ABC-subtype). 4 of these 5 pts exhibited a poor clinical response to ibrutinib, ie, 80% of ABC-DLBCL pts with PIM1 mutations had progressive disease, compared with only 13 of 26 (ie, 50%) ABC-DLBCL pts without PIM1 mutations. Subsequent characterization of the mutant PIM1 proteins (L2V, P81S, and S97N) confirmed that they were more stable than WT PIM1, suggesting increased protein levels by 2 potential mechanisms (WT PIM1 gene up-regulation or increased mutant PIM1 protein half-life). The impact of these mutations on PIM1 function and ibrutinib sensitivity is under investigation. Conclusions: Ibrutinib-resistant ABC-DLBCL cells have increased PIM1 expression, and synergistic growth suppression was observed when ibrutinib was combined with a pan-PIM inhibitor. PIM1 mutations identified in ABC-DLBCL pts with poor responses to ibrutinib contributed to increased PIM1 protein stability. A better understanding of the role of PIM1 in ibrutinib-resistant ABC-DLBCL tumors could provide a rationale for the design of combination therapies. Figure 1. Combination of ibrutinib and a pan-PIM inhibitor in the HBL-1 xenograft model. Ibrutinib and PIM inhibitor treatment suppressed tumor growth by 62% compared with the vehicle-treated group (*p < 0.01, repeated measures MANOVA adjusted univariate F-test). Figure 1. Combination of ibrutinib and a pan-PIM inhibitor in the HBL-1 xenograft model. Ibrutinib and PIM inhibitor treatment suppressed tumor growth by 62% compared with the vehicle-treated group (*p < 0.01, repeated measures MANOVA adjusted univariate F-test). Disclosures Kuo: Pharmacyclics LLC, an AbbVie Company: Employment. Hsieh:pharmacyclics LLC, an AbbVie Company: Employment. Schweighofer:Pharmacyclics LLC, an AbbVie Company: Employment. Cheung:Pharmacyclics LLC, an AbbVie Company: Employment. Wu:Pharmacyclics LLC, an AbbVie Company: Employment. Apatira:Pharmacyclics LLC, an AbbVie Company: Employment. Sirisawad:Pharmacyclics LLC, an AbbVie Company: Employment. Eckert:Pharmacyclics LLC, an AbbVie Company: Employment. Liang:Pharmacyclics LLC, an AbbVie Company: Employment. Hsu:Pharmacyclics LLC, an AbbVie Company: Employment. Chang:Pharmacyclics LLC, an AbbVie Company: Employment.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 30-30
Author(s):  
Wu Yin ◽  
Nie Zhe ◽  
Andrew Placzek ◽  
Michael Trzoss ◽  
Goran Krilov ◽  
...  

Introduction: MALT1 (mucosa-associated lymphoid tissue lymphoma translocation protein 1), was identified as a translocation protein fused with cIAP2 in mucosa-associated lymphoid tissue (MALT) B cell lymphomas. MALT1, a key mediator of NF-κB signaling and the main driver of a subset of B-cell lymphomas, functions via formation of a complex with CARMA1 and BCL10 to mediate antigen receptor-induced lymphocyte activation. MALT1 has been considered as a potential therapeutic target for several non-Hodgkin B cell lymphomas as well as chronic lymphocytic leukemia (CLL). Here, we describe the discovery of novel, potent MALT1 inhibitors that result in antiproliferative effects in non-Hodgkin B-cell lymphoma cells. Results: We have identified novel small molecule MALT1 inhibitors using our proprietary physics-based Free Energy Perturbation (FEP+) modeling technology. Our compounds show potent (sub nM) inhibition of MALT1 enzymatic activity, as well as high binding affinity (sub nM) to MALT1 protein measured by Surface Plasmon Resonance (SPR). BCL10 is a binding partner of MALT1 that is cleaved by MALT1 at the C-terminus. Our inhibitors were efficacious in a target engagement assay showing prevention of BCL10 cleavage in Activated B-cell (ABC) subtype of diffuse large B cell lymphoma (DLBCL) cell lines OCI-LY3 and OCI-LY10, which are Bruton tyrosine kinase (BTK) inhibitor ibrutinib-resistant and -responsive respectively. Our compounds are potent inhibitors of IL10 secretion in both OCI-LY3 and OCI-LY10 cells, which is consistent with the inhibition of NF-κB signaling. We also examined the effect of our MALT1 inhibitors on ABC-DLBCL cell proliferation. Our inhibitors demonstrated potent anti-proliferative effects in both OCI-LY3 and OCI-LY10 cell lines, as well as synergistic effects with ibrutinib in a BTKi sensitive ABC-DLBCL cell panel. Examinations of a protease panel and off-target safety screening panel, as well as in vivo high dose tolerability study showed our compound had excellent selectivity and significant safety margin. Plasma IL10 and tumor BCL10 have been identified as robust PD markers in PK/PD studies in both OCI-LY3 and OCI-LY10 tumor bearing mice. Dose-dependent tumor growth inhibition was observed after 3 weeks of treatment in OCI-LY3 xenograft model, with efficacy also observed in combination with venetoclax. Ongoing work: We are continuing to explore the synergistic effects of our compounds with BTK inhibitors in B-cell lymphoma mouse models. Preliminary data showed potent inhibition of IL-2 secretion in Jurkat cells from our compound treatment. Additional studies are ongoing to elucidate the role of MALT1 inhibition in Treg as well as Teffector cells in vitro and in vivo. Refinement of the current inhibitor series, using co-crystal structures, is in progress in preparation for further development of optimized molecules. Conclusion and Future Plans: We have identified novel potent MALT1 protease small molecule inhibitors that are efficacious in the in vitro B-cell lymphoma cell proliferation assays and in the in vivo B-cell lymphoma xenograft model. Our data suggest that targeting MALT1 may expand therapy options for patients with selected B-cell lymphomas, such as ABC-DLBCL. Our work provided insight into the anti-tumor efficacy of our inhibitors in B-cell lymphomas as single agent, and ongoing work will continue to assess the potential combination with BTKi to overcome drug-induced resistance in patients with relapsed/refractory B-cell lymphoma. Disclosures Yin: Schrodinger: Current Employment, Current equity holder in publicly-traded company. Zhe:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Placzek:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Trzoss:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Krilov:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Feng:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Lawrenz:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Pelletier:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Lai:Triplet Therapeutics: Current Employment, Current equity holder in private company. Bell:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Calkins:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Grimes:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Tang:Schrodinger: Current Employment, Current equity holder in publicly-traded company. McRobb:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Gerasyuto:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Feher:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Mondal:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Jensen:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Wright:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Akinsanya:Schrodinger: Current Employment, Current equity holder in publicly-traded company.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3470-3470 ◽  
Author(s):  
Li Long ◽  
Xia Tong ◽  
Montesa Patawaran ◽  
Sharon L. Aukerman ◽  
Bahija Jallal ◽  
...  

Abstract CD40 is expressed on all B-cell malignancies, including multiple myeloma, and represents an attractive target for antibody therapy. CHIR-12.12 is a fully human, highly potent, IgG1 antagonistic anti-CD40 monoclonal antibody generated using XenoMouse® mice (Abgenix, Inc). CHIR-12.12 can mediate antitumor activity by at least two mechanisms: blocking CD40-ligand-mediated survival signals and killing tumor cells by antibody-dependent cellular cytotoxicity (ADCC). We have previously reported that CHIR-12.12 mediates stronger in vitro killing of CD40+- and CD20+-expressing human non-Hodgkin’s lymphoma and lymphoblastoid B cells by ADCC than rituximab and significantly inhibits the growth of rituximab-responsive (Daudi) and rituximab-resistant (Namalwa) human lymphoma and lymphoblastoid B-cell (IM-9) xenografts in vivo. In this study, we examined the in vitro and in vivo efficacy of CHIR-12.12 against the human multiple myeloma cell line KMS-12-BM. CHIR-12.12 induced lysis of KMS-12-BM cells by ADCC in a dose-dependent manner, reaching maximum cell lysis at 0.1μg/ml with an EC50 of 17.5 pM. CHIR-12.12 efficacy in vivo was evaluated in orthotopic and subcutaneous KMS-12-BM xenograft models. In the staged orthotopic model, tumor cells were delivered intravenously and treatment was initiated 7 days post cell implantation. CHIR-12.12 significantly prolonged the median survival of tumor-bearing mice in a dose-dependent manner, with a median survival of 78 and 98 days in the groups treated with 1 mg/kg and 10 mg/kg CHIR-12.12 weekly, respectively, compared to a median survival time of 68 days in the control IgG1 group (P<0.0001). Bortezomib administered i.v. twice weekly at 0.5 or 1 mg/kg showed no survival benefit. In the staged subcutaneous model, CHIR-12.12 was administered weekly at 1 and 10 mg/kg after the mean tumor volume reached 100mm3. CHIR-12.12 significantly inhibited tumor growth, with a tumor volume reduction of 42% (P<0.05) and 63% (P<0.01), respectively. Bortezomib and melphalan/prednisone did not inhibit KMS-12-BM tumor growth at the doses and schedules reported for other human multiple myeloma xenograft models. Western blot analysis and immunohistochemical staining showed significantly increased levels of cleaved PARP in KMS-12-BM s.c. tumors 7 days after the initiation of CHIR-12.12 treatment, suggesting the induction of cell death by CHIR-12.12. Taken together, these data demonstrate that the anti-CD40 mAb CHIR-12.12 has potent activity against human multiple myeloma cells in vitro and in xenograft models in vivo. Currently CHIR-12.12 is in Phase I clinical trials for the treatment of B-cell malignancies.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5214-5214
Author(s):  
Lilin Zhang ◽  
Fumiko Nomura ◽  
Youichi Aikawa ◽  
Yukio Sudo ◽  
Kazuhiro Morishita ◽  
...  

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.


2013 ◽  
Vol 118 (4) ◽  
pp. 838-845 ◽  
Author(s):  
Takashi Watanabe ◽  
Toshiyuki Ohtani ◽  
Masanori Aihara ◽  
Shogo Ishiuchi

Object Blockade of Ca++-permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (AMPAR) inhibits the proliferation of human glioblastoma by inhibiting Akt phosphorylation, which is independent of the phosphatidylinositol 3-kinase pathway. Inhibiting platelet-derived growth factor receptor (PDGFR)–mediated phosphorylation causes growth inhibition in glioblastoma cells. The authors of this study investigated the effects of YM872 and AG1296, singly and in combination and targeting different pathways upstream of Akt, on Akt-mediated tumor growth in glioblastoma cells in vivo and in vitro. Methods The expression of AMPAR, PDGFR, and c-kit in glioblastoma cells was analyzed via immunofluorescence. Glioblastoma cells, both in culture and in xenografts grown in mice, were treated with YM872 and AG1296, singly or in combination. Inhibition of tumor growth was observed after treatment in the xenograft model. Cell proliferation assays were performed using anti–Ki 67 antibody in vivo and in vitro. The CD34-positive tumor vessel counts within the vascular hot spots of tumor specimens were evaluated. Phosphorylation of Akt was studied using Western blot analysis. Results Combined administration of YM872 and AG1296 had a significant enhanced effect on the inhibition of cell proliferation and reduction of tumor vascularity in the xenograft model. These agents singly and in combination demonstrated a significant reduction of Akt phosphorylation at Ser473 and inhibition of tumor proliferation in vitro, although combined administration had no enhanced antitumor effects. Conclusions The strongly enhanced antitumor effect of this combination therapy in vivo rather than in vitro may be attributable to disruption of the aberrant vascular niche. This combination therapy might provide substantial benefits to patients with glioblastoma.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 5123-5123 ◽  
Author(s):  
Mark Joseph Axelrod ◽  
Peter Fowles ◽  
Jeff Silverman ◽  
Astrid Clarke ◽  
Jennifer Tang ◽  
...  

Abstract Background Entospletinib (GS-9973) selectively inhibits spleen tyrosine kinase (SYK), a critical signaling component of the BCR pathway that is expressed primarily in cells of hematopoietic lineage including normal and malignant B-lymphocytes. Entospletinib is currently in phase II clinical trials, where it has demonstrated both a high degree of safety as well as efficacy against chronic lymphocytic leukemia (Sharman, J., et al. Blood, 2015) and other B cell malignancies. Despite these successes, new therapeutic options, including combinations with standard of care agents, are needed in order to achieve the goal of curing disease through finite treatment. We show here that the combination of entospletinib and vincristine causes synergistic apoptosis in vitro in a broad panel of cell lines derived from hematological cancers including diffuse large B cell lymphoma (DLBCL), acute lymphocytic leukemia, follicular lymphom), multiple myeloma, and acute myelogenous leukemia. We also evaluated and compared the in vivo efficacy of entospletinib and vincristine as singe agents and in combination in a DLBCL tumor xenograft model using the SU-DHL-10 cell line. Methods In vitro growth inhibition of a panel of malignant hematological cell lines was assessed using CellTiter-Glo™ Assay (Promega) after 72h incubation with entospletinib or vincristine alone or in combination. Synergy was evaluated using the Bliss model of independence (Meletiadis, J., et al., Med Mycol, 2005). In vivo, SU-DHL-10 cells (5 x 106 cells) were implanted subcutaneously in the axilla in male SCID beige mice. All mice were sorted into study groups on Day 16 such that each group's mean tumor volume fell within 10% of the overall mean (197mm3). Dosing was initiated on Day 16 and animals were dosed for 17 days. Plasma concentrations of entospletinib and vincristine were assessed on Day 19, and the entospletinib 75 mg/kg dose was lowered on Day 22 to 50 mg/kg to approximate the human achievable SYK target coverage of EC80. Efficacy and tolerability were evaluated by tumor measurements and body weight monitored three times weekly. Tumor burden data were analyzed by the application of a two-way analysis of variance (ANOVA), with post-hoc analysis. Results In vitro combinations of entospletinib with low concentrations of vincristine resulted in marked inhibition of cell proliferation and induction of apoptosis in a broad panel of 19 tumor cell lines representing major B cell malignancies including DLBCL. The combination of entospletinib with vincristine had a profound inhibitory effect on proliferation in all subtypes of DLBCL. Entospletinib was evaluated at a concentration equivalent to the Cminof the clinical dose and vincristine was used at concentrations (≤ 10 nM) that had little to no significant single agent effect in these cell lines. In vivo in a SU-DHL-10 xenograft model, entospletinib dosed alone at 25 or 75/50 mg/kg significantly inhibited tumor growth, causing 39% and 20% tumor growth inhibition (TGI), respectively, compared to the vehicle-treated control group. Vincristine administered at either 0.15 and 0.5 mg/kg Q7D x 3 also resulted in significant TGI (42% and 85% TGI, respectively). The addition of entospletinib (75/50 mg/kg) to 0.5 mg/kg or 0.15 mg/kg vincristine resulted in a significant increase in TGI from 85% to 96% (p= 0.001) and 42% to 71% (p< 0.0001), respectively. The addition of entospletinib (25 mg/kg) to vincristine did not significantly increase the tumor growth inhibition. While the groups receiving either entospletinib or vincristine as single agents had no complete or partial tumor regression, 50% of the mice receiving the combination of 75/50 mg/kg entospletinib with 0.5 mg/kg vincristine had partial responses, 8% had complete regression and 8% were tumor free at the end of study (Figure 1). Conclusion Entospletinib and vincristine demonstrated efficacy and tolerability both alone and in combination in the SU-DHL-10 DLBCL cell line xenograft model in SCID beige mice. Vincristine combinations with entospletinib showed significantly greater efficacy than vincristine alone. These data support the further clinical development of entospletinib in combination with vincristine for the treatment of DLBCL. a ENTO: PO: Q12H x 2 (Day 16-32) b VCR: IV: Q7D x 3 (Days 18, 25, 32) Figure 1. Tumor Regressions in an Entospletinib/ Vincristine Treated Murine DLBCL Xenograft Figure 1. Tumor Regressions in an Entospletinib/ Vincristine Treated Murine DLBCL Xenograft Disclosures Axelrod: Gilead Sciences: Employment, Equity Ownership. Fowles:Gilead Sciences: Employment, Equity Ownership. Silverman:Gilead Sciences: Employment, Equity Ownership. Clarke:Gilead Sciences: Employment, Equity Ownership. Tang:Gilead Sciences: Employment, Equity Ownership. Rousseau:Gilead Sciences: Employment, Equity Ownership. Webb:Gilead Sciences: Employment, Equity Ownership. Di Paolo:Gilead Sciences: Employment, Equity Ownership.


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