Thymidylate Synthase Inhibition with the Novel Fluoropyrimidine FdUMP[10] Is Highly Effective Against Acute Lymphoblastic Leukemia

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1505-1505
Author(s):  
Timothy Pardee ◽  
Jamie Jennings-Gee ◽  
Peter Alexander ◽  
William Gmeiner

Abstract Abstract 1505 Despite significant improvements in cure rates in pediatric patients, outcomes in adults with acute lymphoblastic leukemia (ALL) remain dismal with an estimated 5-year survival of less than 10% for patients over the age of 60. Compared to children, ALL in adults is characterized by an increased incidence of poor prognostic cytogenetics, lower complete remission rates, and higher relapse rates. Once relapse occurs in adults, the outcome is truly dismal, with a 6% salvage rate with current therapies. Initial treatment of ALL combines essentially all currently used agents, leaving very few therapies once relapse occurs. There is a clear need for better therapeutic options for these patients. 5-Fluorouracil (5-FU) is a fluoropyrimidine (FP) prodrug that must first be converted to 5-fluoro-2'-deoxyuridine-5'-O-monophosphate (FdUMP) in order to inhibit thymidylate synthase (TS) and shut down tumor thymidine synthesis. It can also be metabolized to a ribose metabolite that interferes with RNA processing and leads to toxicity in any transcriptionally active cell. The profound GI toxicities of 5-FU and lack of potency against ALL has lead to the abandonment of TS inhibition in the treatment of ALL. In contrast, FdUMP[10] is a oligodeoxynucleotide containing 10 FdUMP moieties linked by phosphodiester bonds. FdUMP[10] has profound activity against preclinical models of acute myeloid leukemia (AML), with minimal toxicities. The human T cell ALL cell line, Jurkat, was extremely sensitive to FdUMP[10], with an IC50of 5.4nM (95% CI 4.609–6.417). We sought to determine the activity of FdUMP[10] against additional preclinical ALL models. In vitro, FdUMP[10] exhibited remarkable activity against the human T and B Cell ALL cell lines, DG75, Molt-4, CCRF-CEM, and SUP-B15 with an average IC50 value of 1.83nM (Range 0.21–4.1nM). In two murine ALL cell lines driven by expression of BCR-ABL, FdUMP[10] exhibited even greater activity, with an average IC50 value of 0.662nM (range 0.125–1.2nM). For comparison we also tested 5-FU and cytarabine in the same assay against DG75, MOLT-4 and a BCR-ABL driven murine line. In all cases FdUMP[10] was the most potent agent and was more than 1000 times more potent than 5-FU despite having only 10 times the FP content. In vivo, FdUMP[10] treatment provided a statistically significant increase in survival in a BCR-ABL driven, syngeneic ALL mouse model (p=0.0002 by log rank test). In a separately derived syngeneic model expressing the T315I variant of BCR-ABL, treatment with FdUMP[10] significantly prolonged survival (p=0.0013). In AML models exposure to FdUMP[10] resulted in apoptosis. To assess if ALL cells undergo a similar apoptotic response we exposed human and mouse ALL cells to FdUMP[10] and assessed for apoptosis induction via propidium iodide (PI) and Annexin V staining. As we found previously in AML models, FdUMP[10] exposure resulted in a robust induction of Annexin V and PI staining consistent with an apoptotic response. The level of apoptosis with FdUMP[10] could not be reproduced by 5-FU even when used at 100 times higher concentration. To determine the effect of FdUMP[10] on thymidylate synthase (TS) activity in ALL, Jurkat cells were exposed to 10nM FdUMP[10] or 100nM 5- FU and TS activity was assayed. We found a profound and prolonged inhibition with FdUMP[10] compared to 5-FU, despite the identical amount of fluoropyrimidine. FdUMP[10] is synergistic with doxorubicin and cytarabine in AML models. To assess whether FdUMP[10] could synergize with targeted therapy in ALL, Baf-3 cells expressing BCR-ABL were exposed to the tyrosine kinase inhibitor nilotinib plus FdUMP[10]. The combination was synergistic, with combinatory index values of 0.7113 to 0.4803. In preliminary data in vivo, the combination of FdUMP[10] and nilotinib resulted in a greater reduction in leukemic burden then nilotinib alone. In summary, FdUMP[10] exhibited remarkable activity against human and murine ALL cells in vitro and in vivo by inducing apoptosis and profound TS inhibition, and showing a synergistic benefit when combined with nilotinib. These data demonstrate that TS is a valid target in ALL cells. This fact combined with previous studies demonstrating a favorable toxicity profile, make FdUMP[10] a promising candidate for treatment of ALL. Disclosures: Pardee: Salzburg Therapuetics: Membership on an entity's Board of Directors or advisory committees. Gmeiner:Salzburg Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees.

Blood ◽  
2007 ◽  
Vol 110 (6) ◽  
pp. 2057-2066 ◽  
Author(s):  
Min H. Kang ◽  
Yun Hee Kang ◽  
Barbara Szymanska ◽  
Urszula Wilczynska-Kalak ◽  
Michael A. Sheard ◽  
...  

Abstract Defects in apoptosis signaling contribute to poor outcome in pediatric acute lymphoblastic leukemia (ALL), and overexpression of antiapoptotic Bcl-2 (Bcl-2 and Bcl-XL) family proteins has been observed in ALL. ABT-737 is a small-molecule BH3-mimetic that inhibits the antiapoptotic Bcl-2 family proteins. We evaluated the cytotoxicity of ABT-737 in combination with vincristine, dexamethasone, and L-asparaginase (VXL) in 7 ALL cell lines. Multilog synergistic cytotoxicity was observed in all 7 cell lines with ABT-737 plus L-asparaginase or vincristine, and in 5 of 7 cell lines with ABT-737 plus dexamethasone or VXL. In leukemia cells, but not in normal lymphocytes, ABT-737 plus L-asparaginase induced greater mitochondrial depolarization (JC-1 staining); mitochondrial cytochrome c release; activation of Bax, Bid, and caspases (immunoblotting); and eventually apoptosis (annexin V staining) than did either drug alone. In mouse xenografts derived from patients with ALL at diagnosis (ALL-7) or at relapse (ALL-19), event-free survival (EFS) was significantly enhanced with ABT-737 plus VXL relative to VXL or ABT-737 alone (P ≤ .02). Thus, ABT-737 synergistically enhanced VXL cytotoxicity in ALL cell lines via a mitochondrial death pathway and enhanced EFS in VXL-treated mice bearing ALL xenografts. Combining VXL with a BH3-mimetic warrants clinical investigation in ALL at relapse and potentially in chemotherapy-resistant ALL subgroups.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3007-3007
Author(s):  
Dharminder Chauhan ◽  
Madhavi Bandi ◽  
Ajita V Singh ◽  
Teru Hideshima ◽  
Nikhil C. Munshi ◽  
...  

Abstract Abstract 3007 Background and Rationale: SIRT1 belongs to the silent information regulator 2 (Sir2) family of proteins and functions as NAD+-dependent deacetylase. Previous studies showed that resveratrol, a polyphenolic SIRT1 activator, inhibits tumorigenesis in various solid tumor and hematologic malignancies, including human multiple myeloma (MM) cells. This notion led to the discovery and development of more potent and selective pharmacological activators of SIRT1 as potential anti-cancer therapeutics. In this context, a recent medicinal chemistry research using high-throughput screening, and mass spectrometry identified SRT1720, a small molecule activator of SIRT1 that is structurally distinct from resveratrol. Here, we examined the anti-tumor activity of SRT1720 in MM cells using in vitro and in vivo model systems. Methods and Model: We utilized MM.1S, MM.1R, RPMI-8226, U266, KMS12BM, H929, and INA-6 (an IL-6 dependent) human MM cell lines, as well as purified tumor cells from patients with MM relapsing after prior therapies including lenalidomide or bortezomib. Cell viability, proliferation, and apoptosis assays were performed using trypan blue, MTT, thymidine incorporation, and Annexin V staining. Signal transduction pathways were evaluated using immunoblot analysis, ELISA, and enzymology assays. Results: We first confirmed the functional specificity of SRT1720 against SIRT1 using different experimental strategies. First, we utilized Fluor de Lys Deacetylase Assay to measure whether SRT1720 affects the SIRT1 deacetylase enzymatic activity. Treatment of MM.1R and RPMI-8226 MM cells with SRT1720 markedly increased the deacetylating activity; conversely, pre-treatment of cells with nicotinamide (NAM) - an inhibitor of SIRT1 – significantly blocked SRT1720-triggered deacetylating activity. Second, immunoblot analysis using antibodies specific against acetylated p53 (a known substrate of SIRT1) showed a marked decrease in acetylated state of p53 in SRT1720-treated MM cells. These findings in MM cells confirm SIRT1 as a selective target of SRT1720. We next examined the efficacyof SRT1720 in MM cells. Treatment of MM cell lines and primary patient cells for 24h significantly decreased their viability (IC50 range 3–7 uM) (P < 0.005; n=3) without markedly affecting the viability of normal peripheral blood mononuclear cells, suggesting specific anti-MM activity and a favorable therapeutic index for SRT1720. SRT1720-triggered apoptosis was confirmed in MM.1R and RPMI-8226 cells, evidenced by a marked increase in Annexin V+ and PI- cell population (P < 0.001, n=3). Importantly, SRT1720 induced apoptosis in MM cells even in the presence of bone marrow stromal cells. Mechanistic studies showed that SRT1720-triggered apoptosis in MM cells is associated with 1) activation of caspase-8, caspase-9, caspase-3, and PARP; 2) activation of pATM, CHK2, endoplasmic reticulum stress molecules pEIF2, and BIP; as well as an increase in reactive oxygen species (ROS); 3) inhibition of MM cell growth and survival pathway via NF-kB; and 4) inhibition of VEGF-induced migration of MM cells and associated angiogenesis. Importantly, blockade of pATM using a biochemical inhibitor KU-5593 significantly attenuated SRT1720-induced MM cell death (P value < 0.002; n=2). These data suggest that SRT1720-induced MM cell apoptosis is predominantly mediated by an ATM-dependent apoptotic pathway. We next examined the in vivo efficacy of SRT1720 using a human plasmacytoma xenograft mouse model. Treatment of tumor-bearing mice with SRT1720 (200 mg/kg, 5 days a week for three weeks), but not vehicle alone, significantly (P < 0.008) inhibits MM tumor growth in these mice. Finally, the combination of SRT1720 with bortezomib or dexamethasone triggered synergistic anti-MM activity. Conclusions: These preclinical studies provide the rationale for novel therapeutics targeting SIRT1 to improve patient outcome in MM. Disclosures: Munshi: Millennium Pharmaceuticals: Honoraria, Speakers Bureau. Richardson:Celgene: Membership on an entity's Board of Directors or advisory committees; Millenium: Membership on an entity's Board of Directors or advisory committees. Anderson:Millennium Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2674-2674
Author(s):  
Timothy Pardee ◽  
Jamie Jennings-Gee ◽  
Kristin Stadelman ◽  
David L. Caudell ◽  
William Gmeiner

Abstract The development of imatinib to target the BCR-ABL kinase in chronic phase (CP) CML has changed the natural history of the disease. This success generated much enthusiasm for the approach in the more genetically complex acute lymphoblastic leukemia (ALL). Unfortunately, the durable responses seen in CP CML are not reproduced in BCR-ABL positive ALL. Indeed, all previous attempts to target a single oncogenic pathway in acute leukemias have resulted in transient responses with frequent relapse. An alternative approach is to use agents that target “final common pathways”, i.e. processes that must be accomplished to produce additional leukemia cells regardless of driving mutations. In this paradigm, agents are not judged by differential expression of a target, but by the degree of differential uptake. One pathway to exploit is the known increased uptake of oligonucleotides by ALL cells. F10 is a poison deoxy-oligonucleotide that is a 10mer of the thymidylate synthase (TS) inhibitory 5-fluorouracil (5-FU) metabolite, 5-fluoro-2’-deoxyuridine-5’-O-monophosphate. We sought to determine the uptake and activity of F10 against preclinical ALL models. Using fluorescently labeled F10, we determined that uptake by the human ALL cell lines DG75 and SUP-B15 was rapid and had a profound temperature dependence consistent with an active process. Both cell lines demonstrated increased uptake compared to normal, lineage- depleted marrow cells from C57Bl/6 mice. Using a syngeneic, BCR-ABL-expressing murine ALL model, we confirmed rapid uptake of F10 in vivo. Furthermore, preliminary experiments suggested normal human HSCs have decreased uptake compared to primary patient samples. Consistent with this decreased uptake, F10 treatment did not alter the ability of human HSCs to engraft in immunodeficient mice. F10 treatment resulted in robust induction of apoptosis that could not be equaled by 100 fold more 5-FU. IC50 values for F10 against B6 ALL, Jurkat, DG75, Molt-4, CCRF-CEM, and SUP-B15 were in the picomolar to nanomolar range, with an average value of 2.15 nM (range 0.12 to 5.4 nM). For comparison we also tested 5-FU, doxorubicin, and cytarabine. In all cases, F10 was the most potent agent; over 1000 times more potent than 5-FU. In vivo, F10 treatment was associated with a significant increase in survival in a BCR-ABL driven, syngeneic ALL mouse model (p= 0.0001 by log rank test). Survival was dose-dependent, with median survival extended by 3, 9 or 15 days for 4, 6, or 9 doses, respectively. F10 also protected mice from leukemia-induced weight loss during and for several days after treatment. To confirm the in vivo activity of F10, we treated a separately derived syngeneic model expressing the T315I variant of BCR-ABL. As in the previous model, F10 significantly prolonged survival (p=0.0013). To further extend these results and confirm F10's activity against human ALL cells, we treated DG75, Jurkat, and SUP-B15 xenograft models. As in the murine models, F10 caused regression of disease with several animals cured and resulted in a significant survival benefit (p=0.0112). As the uptake and mechanism of action of F10 is unique we sought to determine the in vivo efficacy of F10 on ALL previously treated with cytarabine. When mice injected with previously treated ALL cells were treated with cytarabine a median survival benefit of only one day (11 vs 12 days) was observed. In contrast F10 treatment resulted in a median survival of 31 days, similar to the survival seen in previously untreated ALL. F10 exposure results in trapped topoisomerase I (Topo1) cleavage complexes in vitro. To determine if this occurs in vivo, we treated leukemic C57Bl/6 or nude mice harboring ALL xenografts with F10. After 24 hours, leukemia cells were harvested and assayed for trapped Topo1 complexes. F10 treatment resulted in detectable trapped Topo1 complexes in both the xenograft and syngeneic models. In summary, F10 exhibited remarkable activity against human and murine ALL cells in vitro and in vivo by inducing apoptosis and trapping Topo1 complexes. These data demonstrate agents that target “final common pathways” but with differential uptake can be safe and effective, even against genetically complex and aggressive leukemias. Disclosures: Pardee: Salzburg Therapeutics: Membership on an entity’s Board of Directors or advisory committees. Gmeiner:Salzburg Therapeutics: Membership on an entity’s Board of Directors or advisory committees.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 280-280 ◽  
Author(s):  
Ernesto Diaz-Flores ◽  
Evan Q. Comeaux ◽  
Kailyn Kim ◽  
Kyle Beckman ◽  
Kara L. Davis ◽  
...  

Abstract Acute lymphoblastic leukemia (ALL) is the most common cancer of childhood. Specific genetic subsets, including hypodiploid ALL, are associated with particularly high rates of relapse. Despite the poor outcomes of hypodiploid B-ALL with traditional therapeutic approaches, there have been no known effective alternative therapies or novel candidates tested to improve outcome. We hypothesized that new therapeutic targets could by identified by integrated biochemical and genomic profiling, combined with functional drug assays in order to determine which pathways play an essential role in transformation. For biochemical profiling, we analyzed multiple pathways commonly deregulated in leukemias using phosphoflowcytometry (including receptor tyrosine kinases, JAK/STAT, MAPK, PI3K, PTEN, Bcl-2 survival and pro-apoptotic family members and p53). We subjected hypodiploid cell lines (NALM-16, MHH-CALL2) and patient derived xenograft samples in vitro to inhibitors against each of these pathways (PP2:Src family;Ruxolitinib: JAK/STAT; PD235901/CI1040: MAPK; GDC-0941, PI-90, PI-103, p110 (a, b, g, d): PI3K isoform specific; PP-242:mTOR; ABT-263/ABT-737: Bcl-2/Bcl-xl, and ABT-199: Bcl-2 specific). We found that the Bcl-2 inhibitors (ABT-263, ABT-737 and ABT-199) and to a lesser extent PI3K pathway inhibitors GDC-0941 and PP-242, but not the MAPK or RTK inhibitors, efficiently reduced proliferation of hypodiploid cells. However, only ABT-263/ABT-199 induced high levels of apoptosis at nanomolar concentrations. Based on the consistent efficacy observed with ABT-199 against hypodiploid patient-derived cells and cell lines in culture, we selected eight cryopreserved, previously xenografted (F3 generation) hypodiploid patient samples (4 low hypodiploid, chromosomal number between 32 and 39; and 4 Near Haploid, chromosomal number between 24 and 31) and three non-hypodiploid patient samples (Ph-positive,Ph-Like and Erg+) for a preclinical trial in immunodeficient mice. Each patient sample was engrafted into six mice, which were randomized to receive vehicle or ABT-199 daily over 60 days (Figure 1). Treatment started when the peripheral blood (PB) human CD45 count reached 15%. A rapid decrease in PB blasts was noted at 7 days (Figure 1). Eighty-five percent of the hypodiploid xenografts survived 60 days with either undetectable or low levels of leukemia in the PB. In contrastPh+ andPh-Like xenografts died within 10-20 days regardless of treatment. Importantly, hypodiploid leukemic blasts gradually emerged after discontinuing ABT-199 after 60 days. Additionally, despite low or undetectable levels of leukemic blasts in PB and reduced levels in bone marrow and spleen, all mice had high percentages of leukemic cells in the liver (Figure 2). In conclusion we have identified the survival protein Bcl-2 as a promising molecular target in hypodiploid B-ALL. ABT-199 for dramatically reduced leukemia cells in vitro and in vivo in patient-derived xenograft models of hypodiploid B-ALL. However, the liver represented a protective niche for these leukemias. In addition, our biochemical characterization of the organ infiltrating blasts collected from mice on trial indicate that the sensitivity of hypodiploid ALL to ABT-199 relies not only on high levels of Bcl-2 and deficiency for other survival proteins such as Bcl-xl but also on high levels of proapoptotic proteins, providing two different signatures that correlate with response to ABT-199. Using genome editing (CRISPR/Cas9) we interrogated the necessity for individual proapoptotic genes, including PUMA, NOXA, and BAD, for ABT-199-induced cell death. This study provides encouraging preclinical data that Bcl-2 may be a promising target for the treatment of hypodiploid B-ALL. Our studies identify signature biomarkers that correlate with drug response and identify essential proteins mediating ABT-199-induced cell death. Importantly, this report also identifies the limitations of using ABT-199 as single drug, and provides the rationale for using combinatorial therapies in order to improve the efficacy of the drug. Disclosures Mullighan: Loxo Oncology: Research Funding; Amgen: Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees. Loh:Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Abbvie: Research Funding.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1801-1801 ◽  
Author(s):  
Susana Hernández-García ◽  
Laura San-Segundo ◽  
Lorena González-Méndez ◽  
Montserrat Martín-Sánchez ◽  
Luis A Corchete ◽  
...  

Abstract Introduction: Filanesib (ARRY-520) is a novel inhibitor of the "kinesin spindle protein" (KSP), which has demonstrated efficacy in heavily pretreated patients with refractory MM, (Lonial et al, ASH 2013). Our preliminary studies demonstrated synergy with standard anti-MM agents, especially with pomalidomide and dexamethasone. This set the stage for a recently activated trial being run by the Spanish MM group investigating FPD in relapsed MM patients. In this abstract we investigate the mechanisms underlying the synergy of the combination. Methods: In vitro action of FPD was evaluated in MM cell lines by MTT assay, bioluminescence, Annexin V staining, cell cycle profile analysis and TMRE staining by flow cytometry. Synergy was quantified with the Calcusyn software. In vivo efficacy was assessed in a subcutaneous plasmacytoma model of MM1S in CB17-SCID mice (The Jackson Laboratory, Bar Harbor, ME, USA). The mechanism of action was analyzed by Western blot, flow cytometry, genomic techniques, immunohistochemistry and immunofluorescence techniques. Results: The triple combination of FPD resulted in clear synergy in multiple myeloma cell lines (MM1S, OPM2, and RPMI8226) with combination indices between 0.4-0.7, and abrogated the effect of the soluble cytokines IL-6 and IGF-I and the protective effect of the adhesion of plasma cells to BMSCs, HS-5 and TERT cells. FPD caused cell cycle arrest in G2/M and specific apoptosis of cells arrested in these proliferative phases (with apoptosis percentage of 5, 23, 58 and 88 for control, poma+dexa, filanesib and FPD, respectively) demonstrated by flow cytometry with DRAQ5 and Annexin-V. Thus, FPD and filanesib in monotherapy treatments induced a similar effect on the cell cycle profile (arrest in G2/M) with a concordant increase of cyclin B1 and phosphorylated Histone H3. Although a secondary increase of KSP protein levels would be expected, pomalidomide and dexamethasone induced a decrease of the levels of this protein, which was still present in the triple combination (FPD). This fact could be contributing to the potentiation observed with the combination. Attending to apoptosis mechanism, proapoptotic stimulus from the extrinsic and intrinsic apoptotic pathways were promoted by pomalidomide and dexamethasone and filanesib, and converged in the triple combination. In this regard, a decrease of MCL-1 (antiapoptotic protein) and a significant increase of the proapoptotic BCL2 family members of the intrinsic pathway like NOXA and BIMEL BIML, BIMS(this last one being the most potent proapoptotic isoform), tBID (extrinsic pathway) and Bax protein were observed. We confirmed that all these proteins were translocated into the mitochondria, resulting in a decrease of the mitochondrial membrane potential by TMRE, increase of permeability and a release of cytochrome C and AIF. These results were confirmed in vivo in a model of subcutaneous plasmacytoma in small (70 mm3) and large (2000 mm3) tumors. In this model we observed a significant reduction of tumor growth, which was correlated with a statistically significant improvement in survival. Changes induced by FPD in the gene expression profile were concordant with the in vitro results as several overexpressed genes belonging to the previous pathways were identified, such as spindle assembly checkpoint (CENP-E and CENP-F) and apoptosis (BCL2L11, gene that codifies BIM protein). Furthermore, IHC of tumors treated with FPD showed more apoptosis by TUNEL and a significant increase of monopolar spindles (2, 0, 53 and 140 per 10 high-power fields, for control, poma+dexa, filanesib and FPD, respectively). Conclusions: The synergy observed with filanesib in combination with pomalidomide and dexamethasone is the result of several coincidental mechanisms: a potentiation of the KSP inhibition with a subsequent increase in monopolar spindle formation and a simultaneous activation of the intrinsic and extrinsic pathways of apoptosis. In this regard, NOXA, BIM, BAX and tBID are probably the central players that, through different mechanisms, inhibit antiapoptotic proteins (MCL-1, BCL2 and BCL-XL) and promote mitochondrial outer membrane permeabilization and the release of apoptogenic factors such us cytochrome C and AIF. This work was funded in part by the company Array BioPharma. Disclosures Tunquist: Array BioPharma: Employment. Mateos:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Onyx: Consultancy; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy. Ocio:Jassen: Honoraria; Celgene: Honoraria, Research Funding; Pharmamar: Consultancy, Research Funding; MSD: Research Funding; Novartis: Consultancy, Research Funding; Mundipharma: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy; Amgen/Onyx: Consultancy, Honoraria, Research Funding; Array BioPharma: Consultancy, Research Funding.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1329-1329
Author(s):  
Jessica Leonard ◽  
Joelle Rowley ◽  
Brandon Hayes-Lattin ◽  
Jeffrey W. Tyner ◽  
Marc Loriaux ◽  
...  

Abstract Introduction: Treatment of adult Philadelphia chromosome positive acute lymphoblastic leukemia (Ph+ ALL) remains a challenge. While the addition of the targeted tyrosine kinase inhibitors (TKI) to standard cytotoxic therapy has greatly improved upfront treatment, treatment related mortality in older adults remains high. A novel induction regimen combines the targeted dual Abl/Src TKI Dasatinib (Sprycel, BMS) with a corticosteroid. After the first 21 days of induction the corticosteroids are tapered due to significant toxicities, particularly in older adults. Unfortunately, remaining on TKI monotherapy renders patients susceptible to the development of TKI resistance and thus identifying targeted agents that could enhance the activity of TKIs is urgently needed. Recently a novel and selective inhibitor of BCL-2, ABT-199 (Venetoclax, AbbVie) has shown impressive activity against other lymphoid malignancies including CLL and NHL. Here we describe the pre-clinical and in vivo efficacy of ABT-199 in combination with dasatinib in Ph+ ALL and propose its potential use in future clinical trials. Methods: Drug efficacy in vitro was determined using the Ph+ ALL cell line SupB15, primary Ph+ ALL sample (12-149), the dasatinib sensitive Pre-B ALL cell line RCH and the CML cell line K562. Cells were treated with dasatinib, ABT199 or in combination for 72 hours. Cell viability was assessed with the colorimetric MTS assay and apoptosis was assessed with annexin V staining. Expression of the BCL family proteins BCL-2 and MCL-1 were assessed via immunoblot. Immunodeficient NSG mice were injected with 12-149, then one week later treated with vehicle, 5 mg/kg dasatinib, 5 mg/kg ABT-199, or the combination daily for 5 days each week. Peripheral blood was obtained every 1-2 weeks to assess for engraftment as defined by the presence of >10% human CD45+ cells in the peripheral blood. Once engrafted, mice were euthanized and examined. Mononuclear cells were extracted and assessed for BCL2 and MCL1 expression. Statistical methods were performed using Calcusyn and PRISM. Results: Susceptibility to BCL2 inhibition: Of the dasatinib sensitive cells tested, SupB15 and 12-149 cells were susceptible to ABT-199 while RCH and K562 cells were not. The ALL cells expressed BCL-2 while the CML cell line expressed BCLx. SupB15 expressed low levels of the antiapoptotic protein MCL1 while RCH cells had relatively higher levels. siRNA of MCL-1 rendered the RCH cells sensitive to inhibition by ABT-199. In SupB15 cells, treatment with ABT-199 alone led to upregulation of MCL-1 at 24h which was prevented by the combination of dasatinib + ABT199. Synergy in Ph+ ALL: The calculated IC50 of dasatinib and ABT199 in SupB15 were 8.8nM and 5.9nM, respectively. The IC50 of equimolar combination was 0.42nM, and synergistic with combination index (CI) values between 0.15 and 0.49. Primary Ph+ ALL xenograft cells showed a similar pattern of synergy to the dasatinib + ABT199 combination. Combination treatment also greatly increased apoptosis as measured by Annexin V staining. Xenograft Studies: Animals were treated with a ten-fold lower dose of dasatinib and ABT199 from prior published data. There was no significant difference in time to engraftment or disease burden between vehicle or single agent ABT-199. In contrast, less than one half of the animals treated with dasatinib engrafted by 90 days while none of the animals treated with both dasatinib and ABT-199 engrafted. Most intriguing was the decrease in disease burden as measured by splenic size in the combination group compared to all other groups (P<0.0001, one-way ANOVA). Analysis of BCL-2 family proteins from mononuclear cells isolated from untreated animals confirmed upregulation of BCL-2 and relatively low levels of MCL-1. Animals treated with ABT-199 had greatly upregulated levels of MCL-1, while those treated with dasatinib or the combination did not. Conclusions: The combination of ABT-199 with dasatinib synergistically targets Ph+ ALL cells both in vitro and in vivo, laying the foundation for further evaluation in vivo for adult Ph+ ALL. As demonstrated by others, malignancies that are particularly susceptible to BCL targeting are those which display high BCL-2 expression and a low MCL-1: BCL-2 ratio. Combined targeted therapies may offer the potential for greater and longer responses without the morbidity associated with cytotoxic chemotherapy, particularly in older adults. Disclosures Tyner: Aptose Biosciences: Research Funding; Janssen Pharmaceuticals: Research Funding; Incyte: Research Funding; Array Biopharma: Research Funding; Constellation Pharmaceuticals: Research Funding. Druker:Cylene Pharmaceuticals: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Oregon Health & Science University: Patents & Royalties; McGraw Hill: Patents & Royalties; Gilead Sciences: Consultancy, Membership on an entity's Board of Directors or advisory committees; Aptose Therapeutics, Inc (formerly Lorus): Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Millipore: Patents & Royalties; Fred Hutchinson Cancer Research Center: Research Funding; Novartis Pharmaceuticals: Research Funding; Sage Bionetworks: Research Funding; MolecularMD: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; ARIAD: Research Funding; Henry Stewart Talks: Patents & Royalties; Leukemia & Lymphoma Society: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncotide Pharmaceuticals: Research Funding; CTI Biosciences: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Research Funding; Roche TCRC, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Blueprint Medicines: Consultancy, Equity Ownership, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Consultancy.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shuiyan Wu ◽  
You Jiang ◽  
Yi Hong ◽  
Xinran Chu ◽  
Zimu Zhang ◽  
...  

Abstract Background T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive disease with a high risk of induction failure and poor outcomes, with relapse due to drug resistance. Recent studies show that bromodomains and extra-terminal (BET) protein inhibitors are promising anti-cancer agents. ARV-825, comprising a BET inhibitor conjugated with cereblon ligand, was recently developed to attenuate the growth of multiple tumors in vitro and in vivo. However, the functional and molecular mechanisms of ARV-825 in T-ALL remain unclear. This study aimed to investigate the therapeutic efficacy and potential mechanism of ARV-825 in T-ALL. Methods Expression of the BRD4 were determined in pediatric T-ALL samples and differential gene expression after ARV-825 treatment was explored by RNA-seq and quantitative reverse transcription-polymerase chain reaction. T-ALL cell viability was measured by CCK8 assay after ARV-825 administration. Cell cycle was analyzed by propidium iodide (PI) staining and apoptosis was assessed by Annexin V/PI staining. BRD4, BRD3 and BRD2 proteins were detected by western blot in cells treated with ARV-825. The effect of ARV-825 on T-ALL cells was analyzed in vivo. The functional and molecular pathways involved in ARV-825 treatment of T-ALL were verified by western blot and chromatin immunoprecipitation (ChIP). Results BRD4 expression was higher in pediatric T-ALL samples compared with T-cells from healthy donors. High BRD4 expression indicated a poor outcome. ARV-825 suppressed cell proliferation in vitro by arresting the cell cycle and inducing apoptosis, with elevated poly-ADP ribose polymerase and cleaved caspase 3. BRD4, BRD3, and BRD2 were degraded in line with reduced cereblon expression in T-ALL cells. ARV-825 had a lower IC50 in T-ALL cells compared with JQ1, dBET1 and OTX015. ARV-825 perturbed the H3K27Ac-Myc pathway and reduced c-Myc protein levels in T-ALL cells according to RNA-seq and ChIP. In the T-ALL xenograft model, ARV-825 significantly reduced tumor growth and led to the dysregulation of Ki67 and cleaved caspase 3. Moreover, ARV-825 inhibited cell proliferation by depleting BET and c-Myc proteins in vitro and in vivo. Conclusions BRD4 indicates a poor prognosis in T-ALL. The BRD4 degrader ARV-825 can effectively suppress the proliferation and promote apoptosis of T-ALL cells via BET protein depletion and c-Myc inhibition, thus providing a new strategy for the treatment of T-ALL.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 41-42
Author(s):  
Philip C. Amrein ◽  
Karen K. Ballen ◽  
Kristen E. Stevenson ◽  
Traci M. Blonquist ◽  
Andrew M. Brunner ◽  
...  

Introduction: While progress has been made in the treatment of childhood leukemia, the outlook for patients &gt;60 years of age with acute lymphoblastic leukemia (ALL) is poor with complete remission rates (CR) of approximately 60% and 3-year survivals (OS) of less than 15%. Intensified treatment in a later CALGB trial showed little improvement with a CR=61% and 5-year OS=6% (Stock, Cancer 2013). Ixazomib is an oral proteasome inhibitor, which has shown single agent activity and promising combination activity in pediatric ALL patients (Messinger, Blood 2012). We sought to assess the safety and tolerability, as well as early efficacy of adding ixazomib to a current MGH-DFCI/HCC multi-agent regimen for older adults with ALL. Methods: Patients aged 51 to 75 years of age with newly diagnosed B-ALL and T-ALL were screened for eligibility. Patients with mature ALL (including Burkitt's) were excluded. Patients with Philadelphia chromosome positive ALL (BCR-ABL1+) were eligible, and dasatinib was added to the chemotherapy on Day 10 for these patients. The chemotherapy treatment schedule from induction through maintenance is outlined in Table 1. A standard 3 + 3 patient cohort dose escalation design was used to determine the maximum tolerated dose (MTD) of ixazomib during induction for these patients, the primary objective of the trial. After consolidation I, patients in complete remission (CR) with a suitable donor were offered a hematopoietic stem cell transplantation (HSCT) as per institutional guidelines. Those not going to HSCT continued therapy as noted in the table. Results: There were 19 patients with B-ALL enrolled, none with T-ALL. Among these patients, 7 harbored BCR-ABL1 rearrangements. The median age was 65 years, 74% were male, and 90% had a performance status 0 or 1. The MTD was 2.3 mg of ixazomib, as 2 patients at 3.0 mg developed DLT's: a grade 3 peripheral neuropathy and a grade 5 acute kidney injury (Table 2). Grade 3 and 4 toxicities encountered at any time consisted mainly of grade 4 neutropenia in 13 patients and grade 4 thrombocytopenia in 12 patients. One patient experienced grade 3 neutropenia and 5 patients experienced grade 3 thrombocytopenia. Two patients with grade 2 neuropathy did not meet the definition of DLT. Among the 19 patients, 15 (79%, [95% confidence interval (CI), 54-94%]) achieved CR (14) or CRi (1), and 5 patients went on to HSCT. The median follow-up time was 2 years (range, 1-5) for 8 patients remaining alive. The 1-year overall survival estimate was 53% [95% CI, 29-72%], while the 2-year overall survival estimate was 47% [95% CI, 24-67%]. Conclusions: A dose of 2.3 mg of ixazomib in combination with induction chemotherapy among older patients with ALL was well-tolerated and associated with a promising rate of complete remission. Disclosures Amrein: Takeda: Research Funding; AstraZeneca: Consultancy, Research Funding; Amgen: Research Funding. Brunner:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Research Funding; AstraZeneca: Research Funding; Forty-Seven Inc: Membership on an entity's Board of Directors or advisory committees; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding. Hobbs:Novartis: Honoraria; Celgene/BMS: Honoraria; Jazz: Honoraria; Constellation: Honoraria, Research Funding; Incyte: Research Funding; Merck: Research Funding; Bayer: Research Funding. Neuberg:Celgene: Research Funding; Pharmacyclics: Research Funding; Madrigak Pharmaceuticals: Current equity holder in publicly-traded company. Fathi:Takeda: Consultancy, Research Funding; Agios: Consultancy, Research Funding; PTC Therapeutics: Consultancy; Amphivena: Consultancy; Astellas: Consultancy; Daiichi Sankyo: Consultancy; Novartis: Consultancy; Newlink Genetics: Consultancy; Pfizer: Consultancy; Blueprint: Consultancy; Trillium: Consultancy; Kura Oncology: Consultancy; Forty Seven: Consultancy; Jazz: Consultancy; Boston Biomedical: Consultancy; BMS/Celgene: Consultancy, Research Funding; Kite: Consultancy; Trovagene: Consultancy; Amgen: Consultancy; Seattle Genetics: Consultancy, Research Funding; Abbvie: Consultancy. OffLabel Disclosure: MLN 9708, ixazomib is FDA approved for multiple myeloma. In this trial it is used to treat acute lymphoblastic leukemia.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3816-3816 ◽  
Author(s):  
Ryan J. Daley ◽  
Sridevi Rajeeve ◽  
Charlene C. Kabel ◽  
Jeremy J. Pappacena ◽  
Sarah E. Stump ◽  
...  

Introduction: Asparaginase (ASP) has demonstrated a survival benefit in pediatric patients (pts) with acute lymphoblastic leukemia (ALL) and is now part of standard-of-care frontline treatment. As a result, asparaginase preparations have been incorporated into the treatment of adult ALL to improve outcomes. Pegaspargase (PEG-ASP), a modified version of asparaginase with prolonged asparagine depletion, appears to be safe in adults up to age 40 (Stock, et al., Blood, 2019), but is associated with a unique spectrum of toxicities, the risks of which appear to increase with age. Therefore, the safety of PEG-ASP remains a significant concern in older adults w/ ALL. Methods: We conducted a single center retrospective chart review of pts age ≥40 years who received PEG-ASP as part of frontline induction/consolidation or reinduction, between March 2008 and June 2018 at Memorial Sloan Kettering Cancer Center. The primary objective was to evaluate the tolerability and toxicity of PEG-ASP based on the incidence and severity of ASP-related toxicities (hypersensitivity reactions, hypertriglyceridemia, hyperbilirubinemia, transaminitis, pancreatitis, hypofibrinogenemia, etc) according to the Common Terminology Criteria for Adverse Events, version 4.03. Laboratory values recorded were either the peak or the nadir, the more appropriate for toxicity assessment, within a 4-week period following PEG-ASP administration. Secondary objectives were to determine the total number of doses of PEG-ASP administered in comparison to the number of doses intended, and to characterize the rationale for PEG-ASP discontinuation when applicable. Fisher's exact test was used to compare the incidence of PEG-ASP toxicities with respect to pt and treatment characteristics (regimen, age, BMI, gender, Philadelphia chromosome positive (Ph+) vs. Ph-, presence of extramedullary disease, PEG-ASP dose). P values were not adjusted for multiple comparisons. Results: We identified 60 pts with ALL (40 B-ALL and 20 T-ALL) who received at least one dose of PEG-ASP. Nine pts were Ph+. The median pt age at initiation of the treatment was 53, (range, 40 to 80), and 19 pts had a BMI ≥30 kg/m2. Forty-four pts received treatment for newly diagnosed ALL, and 16 pts for relapsed disease. Table 1 lists pt baseline characteristics. Among the 44 pts with newly diagnosed ALL, 27 pts received PEG-ASP as part of pediatric or pediatric-inspired regimens at doses of 2000 - 2500 units/m2, and 1 pt received a modified dose of 1000 units/m2 due to age. The remaining 16 pts received PEG-ASP at doses of 1000 - 2000 units/m2 for consolidation, per established adult regimens (ALL-2 and L-20; Lamanna, et al., Cancer, 2013). Grade 3/4 ASP-related toxicities with a >10% incidence included: hyperbilirubinemia, transaminitis, hypoalbuminemia, hyperglycemia, hypofibrinogenemia, and hypertriglyceridemia. Frontline treatment regimens in which PEG-ASP was used in consolidation cycles only (ALL-2, L-20) were associated w/ a lower incidence of hyperbilirubinemia (p=0.009) and hypertriglyceridemia (p<0.001) compared to those regimens that included PEG-ASP during induction (pediatric/pediatric-inspired regimens) (Table 2). Younger age (40-59 vs. ≥60 years) was associated with a greater risk of hypertriglyceridemia (p<0.001) and higher PEG-ASP dose (≥2000 vs. <2000 units/m2) was associated with a greater risk of hypertriglyceridemia and hypofibrinogenemia (p=0.002 and p=0.025, respectively). Thirty-eight pts (63%) received all intended doses of PEG-ASP. Six pts stopped PEG-ASP to proceed to allogeneic hematopoietic stem cell transplantation (5 in CR1, 1 in CR2), and 7 pts stopped for hypersensitivity reactions. Hepatotoxicity was the only ASP-related toxicity that led to PEG-ASP discontinuation occurring in 5 pts (hyperbilirubinemia, N=4; transaminitis, N=1). The total number of intended doses of PEG-ASP based on regimens used was 186, and 112 were administered. Conclusion: PEG-ASP was incorporated into the treatment of 60 adult ALL pts age ≥40, with manageable toxicity. Seven pts discontinued PEG-ASP due to hypersensitivity reactions and 5 discontinued due to hepatotoxicity, but other reported toxicities did not lead to PEG-ASP discontinuation and the majority of the pts completed all intended doses of PEG-ASP. This study suggests that with careful monitoring, PEG-ASP can safely be administered in adults ≥40 years of age. Disclosures Rajeeve: ASH-HONORS Grant: Research Funding. Tallman:UpToDate: Patents & Royalties; Oncolyze: Consultancy, Membership on an entity's Board of Directors or advisory committees; Delta Fly Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Rigel: Consultancy, Membership on an entity's Board of Directors or advisory committees; Cellerant: Research Funding; Tetraphase: Consultancy, Membership on an entity's Board of Directors or advisory committees; Nohla: Consultancy, Membership on an entity's Board of Directors or advisory committees; BioLineRx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Orsenix: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; ADC Therapeutics: Research Funding; Biosight: Research Funding; Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; KAHR: Consultancy, Membership on an entity's Board of Directors or advisory committees; Daiichi-Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees. Geyer:Dava Oncology: Honoraria; Amgen: Research Funding. Park:Takeda: Consultancy; Allogene: Consultancy; Amgen: Consultancy; AstraZeneca: Consultancy; Autolus: Consultancy; GSK: Consultancy; Incyte: Consultancy; Kite Pharma: Consultancy; Novartis: Consultancy.


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