scholarly journals Evaluation of Otlertuzumab (TRU-016), an Anti-CD37 ADAPTIRTM Therapeutic in Preclinical Combination Studies with Kinase Inhibitors and a Next Generation Anti-CD20 Mab in Vitro and in Animal Models of Non-Hodgkin’s Lymphoma

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3333-3333
Author(s):  
Jane Gross

Abstract 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. Otlertuzumab is a novel humanized anti-CD37 therapeutic, built on the ADAPTIRTM (modular protein technology) platform that has been shown to mediate caspase-independent direct killing of normal and malignant B-cells, a mechanism of action that appears to be distinct from CD20 therapies. In addition, otlertuzumab results in killing through antibody directed cellular cytotoxicity (ADCC), mediated in part by NK cells. The therapeutic potential of otlertuzumab in the treatment of chronic lymphocytic leukemia (CLL) is currently being investigated in Phase 2 clinical studies in combination with bendamustine or rituximab. Preclinical vitro and in vivocombination studies for NHL to evaluate otlertuzumab in combination with other emerging drugs including kinase inhibitors (PI3K and BTK) and the next generation anti-CD20 mAb obinituzumab are reported here. Methods: The ability of otlertuzumab to interact and increase malignant B cell killing with kinase inhibitors was investigated, including a pan PI3K inhibitor (LY294002), a PI3K delta inhibitor (CAL101(GS-1101, idelalisib)), a PI3K delta/gamma inhibitor (IPI-145, (INK1197)) and an inhibitor of BTK (PCI-32765). Combination studies were assayed in vitro using the Minos (mantle cell lymphoma), DoHH-2 (follicular lymphoma) and Ramos (Burkitt’s B cell lymphoma) cell lines. In addition, studies were performed in vitro to test the combination of otlertuzumab and obinituzumab. Individual drugs were tested alone or in combination with otlertuzumab. Combination index analyses were performed for drug combinations over the 20-90% effect levels. To determine whether in vitro synergy could be repeated in vivo, the tumor line with the best in vitro combination characteristics was utilized in xenograft tumor models and treated with otlertuzumab ± LY294002 or otlertuzumab ± PCI-32765 or otlertuzumab ± obinituzumab. Results: Combination index analyses determined that the killing effects of otlertuzumab were synergistic with the pan PI3K inhibitor LY294002, demonstrating comparable results in all three cell lines tested in vitro. The combination of otlertuzumab and the BTK inhibitor PCI-32765 demonstrated synergy in vitro with the Ramos and Minos cell lines. The PI3K delta inhibitor (idelalisib) also demonstrated synergistic activity with all three cell lines when tested in combination with otlertuzumab in vitro. Finally, combination index analyses determined that the killing effects of otlertuzumab were synergistic with the obinituzumab, demonstrating comparable results in all three cell lines tested in vitro. In vivo, the combination of otlertuzumab plus the pan PI3K inhibitor (LY294002) or otlertuzumab plus obinituzumab resulted in greater efficacy relative to each agent alone in the DoHH-2 xenograft tumor models. The combination of otlertuzumab with PCI-32765 resulted in significant delay of tumor outgrowth compared to PCI-32765 alone in the MINO xenograft model of NHL. In vivo results indicated that the in vitro synergy results were applicable to a more complex in vivodisease model. Conclusions: Otlertuzumab tested in combination with multiple kinase inhibitors or next generation anti-CD20 had increased cell killing of NHL cell lines in vitro over that observed for each agent alone. Furthermore, the combinations of otlertuzumab with either obinituzumab, LY294002 or PCI-32765 displayed greater anti-tumor activity in vivo than each of the agents alone. These results provide preclinical rationale for the potential combinations of otlertuzumab with several emerging therapeutics for the treatment of NHL and related B-cell malignancies, including CLL. Disclosures Gross: Emergent BioSolutions Inc: Employment.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2522-2522 ◽  
Author(s):  
Nishitha Reddy ◽  
Raymond Cruz ◽  
Francisco Hernandez-Ilizaliturri ◽  
Joy Knight ◽  
Myron S. Czuczman

Abstract Background: Lenalidomide is a potent thalidomide analogue shown to activate both the innate and adoptive immune system, inhibit angiogenesis, and modify the tumor microenvironment. While lenalidomide has received approval by the U.S. Federal Drug Administration (FDA) for the treatment of various hematological conditions, ongoing clinical trials are addressing its role in the treatment of B-cell lymphomas. There is a dire need to develop novel well-tolerated, therapies which combine various target-specific agents such as lenalidomide and monoclonal antibodies (mAbs). We previously demonstrated that lenalidomide is capable of expanding natural killer (NK) cells in a human-lymphoma-bearing SCID mouse model and improve rituximab anti-tumor activity in vivo. Methods: In our current work we studied the effects of lenalidomide on the biological activity of a panel of mAbs against various B-cell lymphomas, utilizing various rituximab-sensitive (RSCL) and rituximab-resistant cell lines (RRCL) generated in our laboratory from Raji and RL cell lines. Functional assays including antibody-dependant cellular cytotoxicity (ADCC) and complement-mediated cytotoxicity (CMC) were performed to demonstrate changes in sensitivity to rituximab. RSCL and RRCL (1′105 cells/well) were exposed to either lenalidomide (5 μg/ml) or vehicle with or without mAb at a final concentration of 10μg/ml. The mAb panel consisted of two anti-CD20 mAbs: rituximab (Biogen IDEC, Inc.) and hA20, a humanized anti-CD20 mAb (Immunomedics, Inc.); an anti-CD80 mAb (galixumab, Biogen IDEC Inc.), and an anti-CD52 antibody (Alemtuzumab, Berlex Inc.). Changes in DNA synthesis and cell proliferation were determined at 24 and 48 hrs by [3H]-thymidine uptake. For ADCC/CMC studies, NHL cells were exposed to lenalidomide or vehicle for 24 hrs and then labeled with 51Cr prior to treatment with one of various mAbs (10 mg/ml) and peripheral blood mononuclear cells (Effector: Target ratio, 40:1) or human serum, respectively. 51Cr-release was measured and the percentage of lysis was calculated. Changes in antigen (CD20, CD80, and CD52) expression following in vitro exposure to lenalidomide were studied by multicolor flow cytometric analysis. Results: Concomitant in vitro exposure of various RSCL and RRCL cells to lenalidomide and either galixumab, hA20 or alemtuzumab for 24 hrs resulted in improved anti-tumor activity when compared to controls. In addition, pre-incubation of both RSCL and RRCL with lenalidomide rendered cells more susceptible to alemtuzumab-, hA20- and galixumab-mediated ADCC and CMC. No antigen modulation (i.e., upregulation) was observed following in vitro exposure of lenalidomide to NHL cell lines, suggesting an alternative mechanism involved in the improvement antitumor activity observed. Conclusions: Our data suggest that the augmented antitumor effect of lenalidomide is not limited to its combination with rituximab, but also that it augments the antiproliferative and biological activity of alemtuzumab, hA20 and galixumab. Furthermore, these interactions are observed even in our RRCL. Future studies will be directed towards evaluating whether similar activity will be seen in vivo using a human lymphoma-bearing SCID mouse model. (Supported by USPHS grant PO1-CA103985 from the National Cancer Institute.)


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3941-3941
Author(s):  
David M Goldenberg ◽  
Serengulam Govindan ◽  
Tom M Cardillo ◽  
Robert M Sharkey

Abstract Abstract 3941 Background: Monoclonal antibody (MAb) therapy has had a significant impact on the management of B-cell malignancies, but is most often used in combination with chemotherapy. We developed an ADC that combines SN-38, the active component of irinotecan, a topoisomerase I inhibitor, with the internalizing, humanized, anti-CD22 IgG, epratuzumab, and determined its activity alone and in combination with an anti-CD20 antibody therapy (veltuzumab). Methods: Epratuzumab was conjugated with SN-38 (E-SN-38) at a mole ratio of ∼6:1. The conjugate is designed specifically to be released slowly in the presence of serum (50% released over ∼1.5 days), allowing liberation of the drug when internalized, but also being released locally after being bound to the tumor. In vitro and in vivo studies were performed to assess the activity of the conjugate against several subcutaneously- or intravenously-inoculated B-cell lymphoma cell lines. In vivo studies also examined combination therapy using E-SN-38 and the veltuzumab (V). Results: In vitro studies in 4 B-cell lymphoma cells lines (Daudi, Raji, Ramos, WSU-FSCCL) and 4 acute lymphoblastic lymphoma cell lines (697, REH, MN-60, and RS4;11) expressing varying amounts of CD22 showed an IC50 for E-SN-38 in the nanomolar range, confirming potent activity. Nude mice bearing SC Ramos human lymphoma had significant selective anti-tumor activity compared to a control, non-targeting, IgG-SN-38 conjugate, at a dosing regimen of 75 to 250 μg of the conjugates given twice-weekly for 4 weeks. Significant anti-tumor activity was also found in several other cell lines. When combined with veltuzumab, significant improvement in therapeutic activity was observed. For example, median survival in a WSU-FSCCL human follicular B-cell lymphoma IV model with treatment initiated 5 days after implantation was 42 d (0/10 surviving at 160 d) and 91 d (2/10 surviving) for untreated and veltuzumab-treated animals, respectively; 63d (0/10 surviving after 160 d) and >160 d (with 6/10 surviving) for E-SN-38 and E-SN-38 + V, respectively; and 63 d (0/10) and 91 d (2/10) for non-targeting IgG-SN-38 conjugate alone and combined with V). The E-SN-38 conjugate combined with V was significantly better than all treatment or control groups (P ≤ 0.05). Conclusion: E-SN-38 ADC is a potent therapeutic, even at non-toxic dose levels, and shows significantly enhanced efficacy when combined with anti-CD20 immunotherapy, representing an important new ADC treatment regimen. Disclosures: Goldenberg: Immunomedics, Inc.: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Govindan:Immunomedics, Inc.: Employment. Cardillo:Immunomedics, Inc.: Employment.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 377-377 ◽  
Author(s):  
Shruti Bhatt ◽  
Daxing Zhu ◽  
Xiaoyu Jiang ◽  
Seung-uon Shin ◽  
John M Timmerman ◽  
...  

Abstract The anti-CD20 antibody rituximab has revolutionized the treatment for B cell non-Hodgkin lymphomas (NHLs). However, rituximab has limited effectiveness as a single agent in some NHL subtypes and its clinical efficacy is compromised by acquired drug resistance. As a result, many patients still succumb to NHLs. Hence, strategies that enhance the activity of anti-CD20 antibody may improve patient outcome. Interleukin-21 (IL21), a member of the IL2 cytokine family, exerts diverse regulatory effects on natural killer (NK), T and B cells. IL21 has been reported to possess potent anti-tumor activity against a variety of cancers not expressing IL21 receptor (IL21R) through activation of the immune system and is in clinical trials for renal cell carcinoma and metastatic melanoma. We have recently reported that apart from immuno-stimulatory effects, IL21 exerts direct cytotoxicity on IL21R expressing diffuse large B cell lymphoma (DLBCL) and mantle cell lymphoma (MCL) cell lines and primary tumors both in vitro as well in vivo (Sarosiek et al Blood 2010; Bhatt et al AACR 2013). Herein we designed a fusion protein comprising IL21 linked to the N-terminus of anti-CD20 antibody (αCD20-IL21 fusokine) to improve efficacy of its individual components and prolong IL21 half-life. We have verified the expression of full length fusion protein and demonstrated that αCD20-IL21 fusokine retained binding ability to its individual components; CD20 and IL21R, as analyzed by immunofluorescence and flow-cytometry analyses. Similar to our previous study of IL21 in DLBCL, treatment of B cell lymphoma cell lines with fusokine lead to phosphorylation of STAT1 and STAT3, upregulation of cMYC and BAX and downregulation of BCL-2 and BCL-XL, implying the activation of IL21R dependent signaling to trigger cytotoxic effects. In vitro, direct cell death induced by αCD20-IL21 fusokine in DLBCL (RCK8, WSU and Farage) and MCL (Mino, HBL2 and SP53) cell lines was markedly increased compared to its individual components (IL21 and parent αCD20-IgG1 antibody). More importantly, fusokine treatment resulted in cell death of MCL cell lines (L128, G519 and UPN1) that were found to be resistant to IL21 alone treatment. Furthermore, treatment of freshly isolated primary NHL cells with the αCD20-IL21 fusokine also exhibited a 40-50% increase in direct cell death compared to its individual components. Previous studies reported that IL21 enhances antibody-dependent cellular cytotoxicity (ADCC) of therapeutic antibodies by activation of NK cells. ADCC assays using chromium release with purified human NK cells demonstrated that ADCC induced by the parent antibody was enhanced in the presence of IL21 while IL21 alone had minimal effect on the lysis of Raji, Daudi, and Jeko1 target cells. Notably, αCD20-IL21 fusokine demonstrated increased ADCC activity in comparison to parent antibody plus IL21 in Raji, Daudi and Jeko-1 cells (p<0.001, p<0.005 and p<0.001, respectively). Similar results were obtained in primary MCL tumor cells. Consistent with this finding, fusokine treatment resulted in enhanced activation of the NK cells as assessed by CD69 upregulation and CD16 downregulation using flow-cytometry. Complement dependent cytotoxicity (CDC) of the fusokine was similar to the parent antibody and rituximab in Raji cells. Studies analyzing in vivo effects of the fusokine are in progress and will be presented at the meeting. These data strongly suggest that together with direct apoptotic potential, an anti-CD20 IL21 fusokine retains the ability to trigger indirect cell killing mediated via activation of immune effector cells. These dual effects may give remarkable advantage to the fusokine over existing anti-CD20 antibodies for the treatment of NHL tumors. Collectively, our study demonstrates that anti-tumor effects of IL21 and anti-CD20 antibodies can be enhanced by conjugation of IL21 with anti-CD20 antibody that may serve as a novel anti-lymphoma therapy. Disclosures: Rosenblatt: Seattle Genetics, Inc.: Research Funding.


2021 ◽  
Author(s):  
Evelyn M. Mrozek ◽  
Vineeta Bajaj ◽  
Yanan Guo ◽  
Izabela Malinowska ◽  
Jianming Zhang ◽  
...  

Inactivating mutations in either TSC1 or TSC2 cause Tuberous Sclerosis Complex, an autosomal dominant disorder, characterized by multi-system tumor and hamartoma development. Mutation and loss of function of TSC1 and/or TSC2 also occur in a variety of sporadic cancers, and rapamycin and related drugs show highly variable treatment benefit in patients with such cancers. The TSC1 and TSC2 proteins function in a complex that inhibits mTORC1, a key regulator of cell growth, which acts to enhance anabolic biosynthetic pathways. In this study, we identified and validated five cancer cell lines with TSC1 or TSC2 mutations and performed a kinase inhibitor drug screen with 197 compounds. The five cell lines were sensitive to several mTOR inhibitors, and cell cycle kinase and HSP90 kinase inhibitors. The IC50 for Torin1 and INK128, both mTOR kinase inhibitors, was significantly increased in three TSC2 null cell lines in which TSC2 expression was restored.  Rapamycin was significantly more effective than either INK128 or ganetespib (an HSP90 inhibitor) in reducing the growth of TSC2 null SNU-398 cells in a xenograft model. Combination ganetespib-rapamycin showed no significant enhancement of growth suppression over rapamycin. Hence, although HSP90 inhibitors show strong inhibition of TSC1/TSC2 null cell line growth in vitro, ganetespib showed little benefit at standard dosage in vivo. In contrast, rapamycin which showed very modest growth inhibition in vitro was the best agent for in vivo treatment, but did not cause tumor regression, only growth delay.


2018 ◽  
Vol 7 (22) ◽  
pp. 1800830 ◽  
Author(s):  
Li Song ◽  
Xinghua Dong ◽  
Shuang Zhu ◽  
Chunfang Zhang ◽  
Wenyan Yin ◽  
...  

2019 ◽  
Vol 116 (34) ◽  
pp. 16981-16986 ◽  
Author(s):  
Claudio Scuoppo ◽  
Jiguang Wang ◽  
Mirjana Persaud ◽  
Sandeep K. Mittan ◽  
Katia Basso ◽  
...  

To repurpose compounds for diffuse large B cell lymphoma (DLBCL), we screened a library of drugs and other targeted compounds approved by the US Food and Drug Administration on 9 cell lines and validated the results on a panel of 32 genetically characterized DLBCL cell lines. Dasatinib, a multikinase inhibitor, was effective against 50% of DLBCL cell lines, as well as against in vivo xenografts. Dasatinib was more broadly active than the Bruton kinase inhibitor ibrutinib and overcame ibrutinib resistance. Tumors exhibiting dasatinib resistance were commonly characterized by activation of the PI3K pathway and loss of PTEN expression as a specific biomarker. PI3K suppression by mTORC2 inhibition synergized with dasatinib and abolished resistance in vitro and in vivo. These results provide a proof of concept for the repurposing approach in DLBCL, and point to dasatinib as an attractive strategy for further clinical development in lymphomas.


2003 ◽  
Vol 77 (3) ◽  
pp. 2134-2146 ◽  
Author(s):  
Vicky M.-H. Sung ◽  
Shigetaka Shimodaira ◽  
Alison L. Doughty ◽  
Gaston R. Picchio ◽  
Huong Can ◽  
...  

ABSTRACT Hepatitis C virus (HCV) is a major cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Studies of HCV replication and pathogenesis have so far been hampered by the lack of an efficient tissue culture system for propagating HCV in vitro. Although HCV is primarily a hepatotropic virus, an increasing body of evidence suggests that HCV also replicates in extrahepatic tissues in natural infection. In this study, we established a B-cell line (SB) from an HCV-infected non-Hodgkin's B-cell lymphoma. HCV RNA and proteins were detectable by RNase protection assay and immunoblotting. The cell line continuously produces infectious HCV virions in culture. The virus particles produced from the culture had a buoyant density of 1.13 to 1.15 g/ml in sucrose and could infect primary human hepatocytes, peripheral blood mononuclear cells (PBMCs), and an established B-cell line (Raji cells) in vitro. The virus from SB cells belongs to genotype 2b. Single-stranded conformational polymorphism and sequence analysis of the viral RNA quasispecies indicated that the virus present in SB cells most likely originated from the patient's spleen and had an HCV RNA quasispecies pattern distinct from that in the serum. The virus production from the infected primary hepatocytes showed cyclic variations. In addition, we have succeeded in establishing several Epstein-Barr virus-immortalized B-cell lines from PBMCs of HCV-positive patients. Two of these cell lines are positive for HCV RNA as detected by reverse transcriptase PCR and for the nonstructural protein NS3 by immunofluorescence staining. These observations unequivocally establish that HCV infects B cells in vivo and in vitro. HCV-infected cell lines show significantly enhanced apoptosis. These B-cell lines provide a reproducible cell culture system for studying the complete replication cycle and biology of HCV infections.


Cancers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1878 ◽  
Author(s):  
Robert H. Berndsen ◽  
Nathalie Swier ◽  
Judy R. van Beijnum ◽  
Patrycja Nowak-Sliwinska

Patients with advanced colorectal cancer (CRC) still depend on chemotherapy regimens that are associated with significant limitations, including resistance and toxicity. The contribution of tyrosine kinase inhibitors (TKIs) to the prolongation of survival in these patients is limited, hampering clinical implementation. It is suggested that an optimal combination of appropriate TKIs can outperform treatment strategies that contain chemotherapy. We have previously identified a strongly synergistic drug combination (SDC), consisting of axitinib, erlotinib, and dasatinib that is active in renal cell carcinoma cells. In this study, we investigated the activity of this SDC in different CRC cell lines (SW620, HT29, and DLD-1) in more detail. SDC treatment significantly and synergistically decreased cell metabolic activity and induced apoptosis. The translation of the in-vitro-based results to in vivo conditions revealed significant CRC tumor growth inhibition, as evaluated in the chicken chorioallantoic membrane (CAM) model. Phosphoproteomics analysis of the tested cell lines revealed expression profiles that explained the observed activity. In conclusion, we demonstrate promising activity of an optimized mixture of axitinib, erlotinib, and dasatinib in CRC cells, and suggest further translational development of this drug mixture.


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