The HCK/BTK inhibitor KIN-8194 is active in MYD88 driven lymphomas and overcomes mutated BTKCys481 ibrutinib resistance.

Blood ◽  
2021 ◽  
Author(s):  
Guang Yang ◽  
Jinhua Wang ◽  
Li Tan ◽  
Manit Munshi ◽  
Xia Liu ◽  
...  
Keyword(s):  
B Cell ◽  
Malignant Cell ◽  
Pharmacokinetic Parameters ◽  
B Cell Malignancies ◽  
Lymphoma Cells ◽  
Dual Inhibitor ◽  
Growth And Survival ◽  
Activating Mutations ◽  
Ibrutinib Resistance

Activating mutations in MYD88 promote malignant cell growth and survival through HCK mediated BTK activation. Ibrutinib binds to BTKCys481 and is active in B-cell malignancies driven by mutated MYD88. Mutations in BTKCys481 particularly BTKCys481Ser are common in patients with acquired ibrutinib resistance. We therefore performed an extensive medicinal chemistry campaign and identified KIN-8194 as a novel dual inhibitor of HCK and BTK. KIN-8194 showed potent and selective in vitro killing of MYD88 mutated lymphoma cells, including ibrutinib resistant BTKCys481Ser expressing cells. KIN-8194 demonstrated excellent bioavailability and pharmacokinetic parameters, with good tolerance in rodent models at pharmacologically achievable and active doses. Pharmacodynamic studies showed sustained HCK and BTK inhibition for 24 hours following single oral administration of KIN-8194 in MYD88 mutated TMD-8 ABC DLBCL xenografted mice with either wild-type BTK (BTKWT) or BTKCys481Ser expressing tumors. KIN-8194 showed superior survival benefit over ibrutinib in both BTKWT and BTKCys481Ser expressing TMD-8 DLBCL xenografted mice, including sustained complete responses >12 weeks off treatment in mice with BTKWT expressing TMD-8 tumors. The Bcl-2 inhibitor venetoclax enhanced the anti-tumor activity of KIN-8194 in BTKWT and BTKCys481Ser expressing MYD88 mutated lymphoma cells, and markedly reduced tumor growth and prolonged survival in mice with BTKCys481Ser expressing TMD-8 tumors treated with both drugs. The findings highlight the feasibility of targeting HCK, a key driver of mutated MYD88 pro-survival signaling, and provide a framework for the advancement of KIN-8194 for human studies in B-cell malignancies driven by HCK and BTK.

Novel Nanoparticle-Based Approaches To Target B-Cell Malignancies.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4903-4903
Author(s):  
James A. Weaver ◽  
Candice Brannen ◽  
Joseph DeSimone ◽  
Robert Z. Orlowski
Keyword(s):  
B Cell ◽  
Cell Lines ◽  
Malignant Cell ◽  
Burkitt’S Lymphoma ◽  
Burkitt's Lymphoma ◽  
B Cell Malignancies ◽  
Lymphoma Cells ◽  
Cell Clones ◽  
Systemic Treatments ◽  
Burkitt’S Lymphoma Cells

Abstract Introduction: Current approaches to the management of B-cell malignancies include the use of systemic treatments with cytotoxic chemotherapeutics that are not targeted to the tumor cell itself. By improving the ability to deliver lethal agents to the malignant cell clone, such as by targeting the unique tumor idiotype, it is possible that the therapeutic index of our current armamentarium could be improved, thereby optimizing patient outcomes. Nanoparticles represent one attractive approach in this area, since their high surface to volume ratio provides a strong driving force for diffusion into the tumor microenvironment. Methods: Studies were performed using Ramos and SUP-B8 human Burkitt’s lymphoma cell lines, as well as cell lines representative of other hematologic malignancies. Commercially available nanoparticles (Qdots; Invitrogen) as well as nanoparticles generated using PRINT (particle replication in non-wetting templates) technology, were used with idiotype and control peptides. Results: A biotinylated peptide recognized by the SUP-B8 idiotype was bound to streptavidin-containing Qdots, as well as to 200 nm polymeric PRINT particles. Both of these nanoparticle types bound specifically to SUP-B8 Burkitt’s lymphoma cells, as determined by the induction of a fluourescence shift by flow cytometry. These same particles showed no detectable binding to Ramos Burkitt’s lymphoma cells, whose idiotype recognizes a distinct set of peptide sequences, nor to other malignant cell lines, such as RPMI 8226 and ANBL-6 multiple myeloma cells. Moreover, when these nanoparticles were coated with control biotinylated peptides, no binding was seen to any of these cell types, demonstrating the specificity of this approach. Studies utilizing a number of techniques, including fluorescence and electron microscopy, revealed that, after binding, these idiotype-specific particles were internalized by SUP-B8 cells, but not by control cells, or when control peptides were used. Studies in vivo are underway to determine if these targeted nanoparticles can be used for imaging, as well as for delivery of lethal cargoes such as doxorubicin. Conclusion: Nanoparticles can be targeted to specific neoplastic B-cell clones through the use of peptides recognized by the surface idiotype, possibly thereby sparing toxic effects to other B-cell clones, as well as to non-lymphoid cells. The ability to generate nanoparticles of various chemistries, sizes, and porosity, as well as nanoparticles containing a wide array of cargoes, will allow these to be used as platforms for the future personalization of therapy of B-cell malignancies.

Biological and Therapeutic Significance of Thioredoxin-1 (Trx-1) In Diffuse Large B-Cell Lymphomas

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2004-2004
Author(s):  
Lan V Pham ◽  
Michael A. Thompson ◽  
Archito Tamayo ◽  
Changping Li ◽  
Garth Powis ◽  
...  
Keyword(s):  
Cell Growth ◽  
B Cell ◽  
Cell Line ◽  
Effective Control ◽  
B Cell Lymphomas ◽  
Lymphoma Cells ◽  
Growth And Survival ◽  
Thioredoxin 1 ◽  
Large B Cell

Abstract Abstract 2004 Diffuse large B cell lymphomas (DLBCL) are the most common non-Hodgkin (NHL-B) lymphoma. Current treatment is fairly successfully (∼70-80% remission with R-CHOP frontline chemotherapy), but relapse is common (∼50% after 2–3yrs) with poor salvage therapy options and short survival in relapsed/refractory (r/r) DLBCL. The greatest challenge in improving survival of DLBCL patients is overcoming chemo-resistance, which we currently have very little understanding of the basis. Elucidation of molecular pathways and tumor-encoded genes whose expression contribute to the intrinsic resistance and rapid cell growth of lymphoma cells could yield immediate clinical benefits and reveal new therapeutic targets for effective control and treatment of r/r lymphomas. Thioredoxin (Trx) family members play critical roles in the regulation of cellular redox homeostasis. Cancer cells exist in a stressed environment and rely on the Trxs for protection against stress-disregulated redox signaling. The most extensively studied member of the family is Trx-1 whose levels are increased in many human cancers, most likely in direct response to stress. Trx-1 contributes to many of the hallmarks of cancer including increased proliferation, resistance to cell death and increased angiogenesis. Trx-1 is a validated cancer drug target associated with aggressive tumor growth, resistance to standard therapy and decreased patient survival. In this study we showed that the majority of the DLBCL-derived cell lines express high basal levels of thioredoxin-1 (Trx-1) when compared to normal B cells by both Western blotting and real-time PCR. Tissue microarray (TMA) and immunohistochemistry analysis of 100 cases of DLBCL showed that 77% of the cases were positive for Trx-1 and 40% of the cases over-expressed Trx-1. Based on these observations, we hypothesize that aberrant expression of Trx-1 contributes to the development of drug resistance and cell growth and survival phenotype in DLBCL. Inhibition of Trx-1 by small interfering RNA (siRNA) inhibited DLBCL cell line growth in vitro. Down-regulation of Trx-1 also sensitized lymphoma cells to doxorubicin-induced cell growth inhibition. A doxorubicin-resistant human DLBCL cell line (McA), that was highly sensitive to doxorubicin, has been selected by continuously exposing cells to gradually increasing doses of doxorubicin. The resistant phenotype has been retained for over 6 months despite growth in drug-free medium. Western blot analysis detected increased expression of the Trx-1 in the resistant subline. These results indicate that Trx-1 plays a key role in growth and survival, as well as chemoresistance in the pathophysiology of DLBCL. Based on these data, we plan to use small molecule inhibitors in vitro as a proof of principle for possible future human phase I studies. Disclosures: Ford: Cell Point: Research Funding.

NVP-BEZ235, A Dual Inhibitor of Phosphoinositol-3-Kinase (PI3K) and Mammalian Target of Rapamycin (mTOR), Is a Potent Inhibitor of Lymphoma Cell Growth and Survival

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4965-4965 ◽  
Author(s):  
Daniela Buglio ◽  
Manuela Lemoine ◽  
Sattva S. Neelapu ◽  
Francisco Vega ◽  
Donald Berry ◽  
...  
Keyword(s):  
Cell Growth ◽  
Cell Lines ◽  
Lymphoma Cell ◽  
Parp Cleavage ◽  
Lymphoma Cells ◽  
Dual Inhibitor ◽  
Growth And Survival ◽  
Stat Pathway ◽  
Cell Growth And Survival

Abstract Abstract 4965 The Phosphatidylinositol-3-kinase (PI3K)/AKT/mTOR pathway is frequently deregulated in Hodgkin (HL) and non-Hodgkin lymphoma (NHL), and has been linked with tumor cell growth and survival. Although several proteins/enzymes in this pathway can be targeted by a variety of small molecules in vitro and in vivo, it remains unclear which protein target is the ideal for clinical testing. Previous studies demonstrated that the clinical activity of mTOR inhibitors may be attenuated by a negative feedback loop that involves activation of AKT, suggesting that a dual inhibition of AKT and mTOR activation may produce a better therapeutic outcome. To test this hypothesis, we evaluated the in vitro activity of NVP-BEZ235, a dual inhibitor of PI3K and mTOR, in a panel of 13 HL and NHL cell lines. NVP-BEZ235 inhibited cell growth and induced apoptosis in lymphoma cell lines in a time and dose dependent manner. After 48 hours of incubation, the IC50 ranged between 50 and 100 nM, and it was equally effective in ABC and GCB-derived DLBCL cell lines. NVP-BEZ235 induced cell death was primarily due to induction of apoptosis, as evident by the annexin-V and PI dual staining method, and the induction of caspase 3 and PARP cleavage. NVP-BEZ235 effectively inhibited the activation of the PI3K pathway at several steps, including decreasing the phosphorylation level of p-Akt (Ser473), p-Akt (Thr308), p-mTOR, p-4-EBPI and pP70S6K. Because lymphoma cells frequently depend on multiple activated signaling pathways to promote their survival, including the JAK/STAT pathway, we investigated the potential synergy between PI3K and JAK/STAT pathway inhibitors. Lymphoma cells were variably sensitive to the JAK1/2 inhibitor INCB16562 in vitro. Submaximal concentrations of NVP-BEZ235 demonstrated a synergistic activity with INCB16562. Collectively, our data show that the PI3K/mTOR inhibitor NVP-BEZ235 is highly effective against a wide range of lymphoma cell lines, and warrants evaluating it alone and in combination with JAK/STAT inhibitors in phase I/II clinical trials in patients with relapsed lymphoma. Disclosures: No relevant conflicts of interest to declare.

scholarly journals A Novel HCK and BTK Dual Inhibitor Kin-8194 Shows Superior Activity over Ibrutinib and Overcomes BTKC481S Mediated Ibrutinib Resistance in Vitro and In Vivo in MYD88 Mutated B-Cell Lymphomas

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 394-394 ◽  
Author(s):  
Guang Yang ◽  
Jinhua Wang ◽  
Xia Liu ◽  
Manit Munshi ◽  
Jiaji G Chen ◽  
...  
Keyword(s):  
B Cell ◽  
Research Funding ◽  
Scid Mice ◽  
Live Cell ◽  
Pharmacokinetic Studies ◽  
Wild Type ◽  
Dual Inhibitor ◽  
Equity Ownership ◽  
Ibrutinib Resistance

Activating mutations in MYD88 promote malignant cell growth and survival through multiple pathways that include BTK and HCK. HCK is transcriptionally upregulated and activated by mutated MYD88 and in turn activates BTK itself, as well as ERK and AKT. Ibrutinib is a covalent inhibitor that binds to BTKCys481 and shows activity in MYD88 mutated B-cell malignancies, including WM, MZL, ABC DLBCL, and PCNSL. Resistance to ibrutinib on the basis of BTKCys481 as well as downstream mutations is increasingly being recognized. We therefore sought to develop potent and selective inhibitors that target HCK. We developed a non-covalent dual inhibitor, KIN-8194, of HCK and BTK following a screen >220 clinical and preclinical kinase inhibitors, and lead optimization following synthesis >400 analogs. Dual HCK and BTK inhibition was confirmed by both KINOMEscan® and live-cell target engagement studies (KiNativ™ profiling and live cell ATP-biotin competition assay). KIN-8194 showed robust suppression of HCK (IC50<0.495nM) and BTK (IC50=0.915nM) in these studies, and blocked pHCK and pBTK in both wild-type and mutated BTKCys481 WM and ABC DLBCL cells, and primary WM cells. Importantly, KIN-8194 showed selective killing of MYD88 mutated WM and ABC DLBCL cells and overcame resistance to ibrutinib in WM and ABC DLBCL cells engineered to express mutated BTKCys481. KIN-8194 showed excellent microsomal stability across multiple species including human (T1/2=49.5 minutes). Pharmacokinetic studies in mice showed excellent bioavailability (F=55%), serum half-life (T1/2=15.1 hours) and drug clearance (CL=17.4mL/min/kg) amenable to once daily oral dosing. The compounds exhibited an excellent in vitro safety profiling including no relevant inhibition observed against a panel of 100 other receptor targets, including hERG, AMES was negative up to 50 µM, and Cyp inhibition studies showed acceptable inhibition up to 10 µM. Pharmacodynamic studies following oral administration showed that KIN-8194 blocked both pHCK and pBTK in wild-type and mutated BTKCys481 expressing TMD8 ABC DLBCL cells engrafted in NOD SCID mice. Continuous dosing up to 100 mg/kg was well tolerated in these mice. KIN-8194 treated NOD SCID mice xenografted with either wild-type (A) or mutated (B) BTKCys481 TMD cells (N=8/cohort) showed superior tumor growth suppression and survival over vehicle control or ibrutinib treated mice at 50 mg/kg. Among wild-type BTKCys481 TMD8 xenografted mice treated for 6 weeks, elimination of tumor was observed in half the mice with no subsequent growth following 12 additional weeks of observation, consistent with a cure. We therefore describe a novel, highly potent non-covalent dual HCK and BTK inhibitor that is well tolerated in mice, shows selective killing of MYD88 mutated WM and ABC DLBCL cells, and can overcome mutated BTKCys481 related ibrutinib resistance. Disclosures Hunter: Janssen: Consultancy. Castillo:Beigene: Consultancy, Research Funding; TG Therapeutics: Research Funding; Abbvie: Research Funding; Janssen: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding. Gray:Gatekeeper, Syros, Petra, C4, B2S and Soltego.: Equity Ownership; Novartis, Takeda, Astellas, Taiho, Janssen, Kinogen, Voronoi, Her2llc, Deerfield and Sanofi.: Equity Ownership, Research Funding. Treon:Pharmacyclics: Research Funding; BMS: Research Funding; Janssen: Consultancy.

scholarly journals Chimeric CLL-1 Antibody Fusion Proteins Containing Granulocyte-Macrophage Colony-Stimulating Factor or Interleukin-2 With Specificity for B-Cell Malignancies Exhibit Enhanced Effector Functions While Retaining Tumor Targeting Properties

Blood ◽  
1997 ◽  
Vol 89 (12) ◽  
pp. 4437-4447 ◽  
Author(s):  
Jason L. Hornick ◽  
Leslie A. Khawli ◽  
Peisheng Hu ◽  
Maureen Lynch ◽  
Peter M. Anderson ◽  
...  
Keyword(s):  
B Cell ◽  
Fusion Proteins ◽  
Tumor Targeting ◽  
B Cell Malignancies ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Macrophage Colony ◽  
Stimulating Factor

Abstract Although monoclonal antibody (MoAb) therapy of the human malignant lymphomas has shown success in clinical trials, its full potential for the treatment of hematologic malignancies has yet to be realized. To expand the clinical potential of a promising human-mouse chimeric antihuman B-cell MoAb (chCLL-1) constructed using the variable domains cloned from the murine Lym-2 (muLym-2) hybridoma, fusion proteins containing granulocyte-macrophage colony-stimulating factor (GM-CSF) (chCLL-1/GM–CSF) or interleukin (IL)-2 (chCLL-1/IL–2) were generated and evaluated for in vitro cytotoxicity and in vivo tumor targeting. The glutamine synthetase gene amplification system was employed for high level expression of the recombinant fusion proteins. Antigenic specificity was confirmed by a competition radioimmunoassay against ARH-77 human myeloma cells. The activity of chCLL-1/GM–CSF was established by a colony formation assay, and the bioactivity of chCLL-1/IL–2 was confirmed by supporting the growth of an IL-2–dependent T-cell line. Antibody-dependent cellular cytotoxicity against ARH-77 target cells demonstrated that both fusion proteins mediate enhanced tumor cell lysis by human mononuclear cells. Finally, biodistribution and imaging studies in nude mice bearing ARH-77 xenografts indicated that the fusion proteins specifically target the tumors. These in vitro and in vivo data suggest that chCLL-1/GM–CSF and chCLL-1/IL–2 have potential as immunotherapeutic reagents for the treatment of B-cell malignancies.

A Fully Human Anti-CD40 Antagonistic Antibody, CHIR-12.12, Inhibit the Proliferation of Human B Cell Non-Hodgkin’s Lymphoma.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3279-3279 ◽  
Author(s):  
Wen-Kai Weng ◽  
Xia Tong ◽  
Mohammad Luqman ◽  
Ronald Levy
Keyword(s):  
Follicular Lymphoma ◽  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Expression Level ◽  
Primary Lymphoma ◽  
Immunoglobulin Gene ◽  
Dependent Manner ◽  
Lymphoma Cells

Abstract Immunotherapy using anti-tumor antibodies has become a feasible alternative for treating patients with lymphoma. These anti-tumor antibodies may target a specific receptor to disrupt proliferative signaling or mediate their anti-tumor effect by antibody-dependent cellular cytotoxicity (ADCC) or complement-mediated killing. The CD40 antigen is a good target for such anti-tumor antibodies for several reasons: CD40 is expressed on the vast majority of the non-Hodgkin’s B cell lymphomas and it has been proposed that the CD40/CD40L interaction provides a critical survival or proliferative signal for B cell lymphoma, especially the low-grade follicular lymphoma. In addition, B lymphoma cell lines become less sensitive to chemotherapy-induced apoptosis after CD40 cross-linking in an in vitro study. Therefore, an anti-CD40 antagonist that disrupts the CD40/CD40L interaction and mediates effector mechanism could have a therapeutic advantage. In this report, we describe a fully human anti-CD40 antagonistic IgG1 monoclonal antibody, CHIR-12.12 that was generated from mice with a human immunoglobulin gene loci (XenoMouse®mice, Abgenix Inc.). We first compared the antigen expression level of CD40 to the level of CD20, the target for rituximab, on primary lymphoma cells. While the expression level of CD40 was similar between different samples of primary follicular lymphoma cells, it was 10 fold less than the level of CD20. The expression of CD40 and CD20 on chronic lymphocytic leukemia/small lymphocytic lymphoma cells (CLL/SLL) was more variable. However, the level of CD20 was still significantly higher than the level of CD40 in all samples tested (2.4 to 13 fold). While CHIR-12.12 binds to primary lymphoma cells similarly to several other anti-CD40 antibodies, CHIR-12.12 did not induce proliferation of these primary tumore cells. By contrast, an agonist anti-CD40 antibody induced proliferation of these lymphoma cells up to 6-fold over baseline. To study the ability of CHIR-12.12 to interrupt the CD40-CD40L interaction, we cultured lymphoma cells with CD40L-transfected feeder cells in the presence of control IgG1, CHIR-12.12 or rituximab. In this system, the lymphoma cells proliferate in response to CD40-CD40L interaction. The addition of rituximab did not influence the proliferation. However, CHIR-12.12 inhibited the proliferation of follicular lymphoma and of CLL/SLL cells in a dose-dependent manner. The inhibition was observed with antibody concentration at 1 μg/ml and reached maximum of 90% inhibition at 10 μg/ml. We then evaluated the ability of CHIR-12.12 to elicit complement-mediated killing or ADCC. In vitro, rituximab induced complement-mediated cytotoxicity, while CHIR-12.12 did not. However, both CHIR-12.12 and rituximab induced effective ADCC of primary follicular lymphoma cells using purified NK cells from a healthy donor. Even though the level of CD40 is 10-fold less than the level of CD20 on the cell surface of these tumor cells, CHIR-12.12 induced the same degree of ADCC killing as did rituximab. Thus, this novel antagonist CHIR-12.12 antibody both blocks tumor-stimulatory CD40/CD40L interaction and mediates ADCC in the presence of a low number of target antigen. Our results support further development of this antibody to treat patients with B cell lymphoma.

BCL6, p53 and Molecular Targeted Therapy in B-Cell Lymphomas.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1484-1484 ◽  
Author(s):  
Leandro C.A. Cerchietti ◽  
Jose M. Polo ◽  
Gustavo F. Da Silva ◽  
Steve M. Dowdy ◽  
Catoretti M. Giorgio ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
B Cell ◽  
Target Gene ◽  
Target Genes ◽  
Wild Type ◽  
B Cell Lymphomas ◽  
Lymphoma Cells ◽  
Sequential Administration ◽  
Wild Type P53

Abstract The BCL6 transcriptional repressor is an oncogene often constitutively expressed in diffuse large B-cell lymphomas (DLBCL). The oncogenic mechanism of action of BCL6 presumably involves repression of its direct target genes. We recently developed a targeted therapy agent (called BPI - BCL6 peptide inhibitor) that specifically blocks transcriptional repression by BCL6, and which causes apoptosis in lymphoma cells in vitro and in vivo. We present here potent and stable derivatives of BPI able to specifically eradicate lymphoma cells after a single dose in vitro. Expression array studies of BCL6 target genes reactivated by BPI revealed that one such gene is the p53 tumor suppressor. p53 was also recently shown to be BCL6 target gene by Phan et. al., Nature 2004. We find that BCL6 represses p53 in DLBCL cells through recruitment of the SMRT and N-CoR corepressors, which explains how BPI, which blocks recruitment of these corepressors, reactivates p53. We next wished to determine the contribution of BCL6-mediated repression of p53 to lymphomagenesis, and how p53 modulation might affect BCL6 targeted therapy strategies for DLBCL. We found that BPI could induce p53 target gene expression in DLBCL cells with wild-type p53 and that small molecules or peptides that block p53 rescue apoptosis induced by BPI. In contrast, although BPI also induces p53 in DLCBL cells with mutant p53, there was no activation of p53 target genes and no rescue by p53 blocking molecules. However BPI causes apoptosis of DLBCL cells regardless of p53 status indicating the BCL6 mediates its oncogenic actions through both p53 dependent and independent pathways. p53 is usually wild-type in DLBCL and our analysis of >100 patients show that p53 protein is, surprisingly, still expressed in these tumors. These data suggest that p53 is not fully active in DLBCL cells, consistent with the fact that we found that BCL6 also directly represses upstream activators of p53 such as Chk1 and ATR. BCL6 blockade thus can fully restore activity of p53, both by increasing its expression levels and by enhancing its activation by upstream mediators. Accordingly, sequential administration of p53 activating molecules that enhance p53 activity, potently synergizes with BPI in killing lymphoma cells. BPI also synergizes with chemotherapy drugs that act in part through p53, such as doxorubicin. From these studies we conclude that i) BCL6 mediates lymphomagenesis by direct repression of p53 and upstream target gene pathways; ii) BCL6 positive lymphomas are dependent on BCL6 for their survival regardless of whether p53 is wild type or mutated; iii) Sequential targeting of BCL6 and p53 with BPI and a p53 activating molecule or doxorubicin is likely to be a highly effective therapeutic regimen for patients with DLBCL, especially for the majority who have wild-type p53; iv) The new BPI derivatives are sufficiently potent and stable to be tested in the clinical setting.

TRU-016, An Anti-CD37 SMIP™ Biologic, In Combination with Other Therapeutic Drugs In Models of Non-Hodgkin's Lymphoma

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3931-3931 ◽  
Author(s):  
Paul A. Algate ◽  
Jennifer Wiens ◽  
Christy Nilsson ◽  
Mien Sho ◽  
Debra T. Chao ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Follicular Lymphoma ◽  
B Cell ◽  
Cell Lymphoma ◽  
Combination Index ◽  
Growth Delay ◽  
Tumor Growth Delay ◽  
B Cell Malignancies

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.

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