Preclinical Evaluation of Sorafenib in Combination with Cytarabine and Clofarabine in Acute Myeloid Leukemia (AML).

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4202-4202
Author(s):  
Shuiying Hu ◽  
Hongmei Niu ◽  
Shelley Orwick ◽  
Jeffrey Rubnitz ◽  
John Schuetz ◽  
...  
Keyword(s):  
Cell Lines ◽  
Tyrosine Kinases ◽  
Single Agent ◽  
Fixed Ratio ◽  
Mapk Signaling ◽  
Nucleoside Analogues ◽  
U937 Cells ◽  
Intracellular Accumulation ◽  
Antitumor Effects ◽  
Sequential Administration

Abstract Deregulation of receptor tyrosine kinases and downstream signal transduction pathways may promote leukemogenesis by conferring cell proliferation and survival advantages in AML. The multitargeted tyrosine kinase inhibitor sorafenib (with activity against FLT3, c-kit, PDGFR, VEGFR, RAF) has been shown to have potent antitumor effects in AML cell lines with c-kit and FLT3 mutations, possibly by inducing G0/G1 cell cycle block and apoptosis and inhibiting STAT and/or MAPK signaling (S. Hu Proc AACR 2007). Sorafenib has shown single-agent activity in AML, but clinical responses have not been durable, suggesting that sorafenib is likely to be more clinically effective if combined with other antileukemic agents. In this study, we evaluated the antitumor activity of sorafenib in combination with the nucleoside analogues clofarabine and cytarabine in three AML cell lines (MV4-11, THP-1 and U937), which represent different FAB types and variable alterations in tyrosine kinases. Three sequences of administration including simultaneous, pre-chemotherapy, and pre-sorafenib were evaluated with a MTT cellular proliferation assay using 24- to 72-hr exposures (duplicate experiments performed with 8 replicates each). Combined drug effects were analyzed using the computer software CalcuSyn. The combination of clofarabine with sorafenib at a fixed ratio of 5:1 was synergistic to additive or antagonistic in MV4-11 cells (with FLT-3 ITD) depending on sequence; simultaneous > pre-sorafenib > pre-clofarabine with combination index (CI) values at ≥ ED50 of 0.53–0.80, 0.54–1.12, and 0.93–1.20, respectively. The combination of sorafenib and clofarabine was antagonistic in THP-1 and U937 cells with all three sequences evaluated (CI values at ≥ ED50 of 1.25–1.96). The combination of cytarabine with sorafenib at a fixed ratio of 250:1 was synergistic in MV4-11 cells regardless of the sequence of administration with CI values at ≥ ED50 of 0.28–0.77 in all 3 cell lines, representing an approximate 3–4- fold dose reduction index for both drugs. Although studies evaluating cytarabine and sorafenib in THP-1 and U937 cells are pending, results in MV4-11 cells indicate that cytarabine with sorafenib may be more effective than the combination of clofarabine with sorafenib. Combination studies of clofarabine or cytarabine with sorafenib in blasts from children with AML are ongoing. To understand potential differences between the nucleoside analogues when combined with sorafenib, studies were performed to determine the effect of sorafenib 5 μM (pre-treatment for 15 min) on the cellular accumulation (1-hr exposure) of clofarabine and cytarabine in MV4-11 cells (2 to 3 independent experiments performed in duplicate). Sorafenib decreased the intracellular accumulation of clofarabine by about 2-fold, but increased the intracellular accumulation of cytarabine by approximately 2-fold; transporter studies are ongoing to identify the mechanism(s) of the observed differential drug interaction. In conclusion, sorafenib in combination with cytarabine may represent a promising treatment strategy for AML, where simultaneous or sequential administration appears to be equally effective.

scholarly journals Development of an Axl/Mer Dual Inhibitor, ONO-9330547: Promising Single Agent Activity in an Acute Myeloid Leukemia (AML) Model

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 999-999
Author(s):  
Tomoko Yasuhiro ◽  
Toshio Yoshizawa ◽  
Ryu Fujikawa ◽  
Kohei Tanaka ◽  
Tomoya Koike ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Lines ◽  
Tyrosine Kinases ◽  
Treatment Options ◽  
Single Agent ◽  
Xenograft Model ◽  
Treatment Resistance ◽  
Specific Gene ◽  
Dual Inhibitor ◽  
Term Survival

Abstract Purpose: Axl and Mer belong to the TAM (Tyro3, Axl, Mer) family of receptor tyrosine kinases and play a role in regulating cell proliferation, survival, migration and cytokine production. Axl/Mer are over-expressed in various types of haematological and solid tumour cancers and appear to play a key role in epithelial-to-mesenchymal transitions (EMTs), known to be important in tumour metastases and drug resistance. AML is a clonal disease of haematopoietic progenitors characterised by acquired heterogeneous genetic changes that alter cell proliferation and differentiation and Axl is an independent prognostic marker and therapeutic target in AML. Recent studies revealed that AML cells induce expression and secretion of the Axl ligand growth arrest specific gene 6 (Gas6) by bone marrow derived stromal cells (BMDSCs). Gas6 mediates proliferation, survival and chemoresistance of Axl-expressing AML cells, giving rise to a chemoprotective tumour niche environment. Standard chemo-treatment for AML affects not only AML cells but healthy cells which cause severe side effects. In addition, only 40-45% of patients <65 years reach long-term survival with current treatment options and only 10% of patients >65 can be cured. Therefore, there is still a high, unmet medical need for new therapies. ONO-9330547 is a small molecule inhibitor that binds to Axl and Mer kinase with a potency (IC50) of 2.2 and 0.4 nM respectively, therefore, the anti-tumour activity of ONO-9330547 in AML cells was evaluated. Methods: AML cell lines were implanted subcutaneously into female SCID mice. Randomization of mice occurred when mean tumour volume was 100-200 mm3. ONO-9330547 was administered orally at doses up to 3 mg/kg twice daily (BD) for 24 days. Tumour volumes were measured twice a week after initiation of treatment, and tumor volumes were determined using the formula volume (=width2xlength)/2. Animals were euthanized when the tumours reached a maximum volume of 2,000 mm3. Phosphorylation of Axl (P-Axl) and Mer (P-Mer) were detected by Western blotting or Flow cytometry. Results: In AML cell lines assays, ONO-9330547 strongly inhibited both P-Axl and P-Mer with an IC50in the nM range, which resulted in growth inhibitions and inductions of apoptosis. In the MV-4-11 xenograft model, tumour growth inhibition at the final treatment day was 40% in the 0.3 mg/kg BD group and 78% in the 1 mg/kg BD and 100% in the 3 mg/kg BD groups respectively (All treatment groups: P<0.001 vs Vehicle). Specifically, the treatment with ONO-9330547 1 or 3 mg/kg BD resulted in higher and sustained P-Axl inhibition throughout the study, and treatment of 3 mg kg BD resulted in complete remission in all treated mice. Interestingly, up-regulation of Axl and Mer were observed in AML cell lines after the treatment of doxorubicin or Ara-C. The combination of ONO-9330547 with Ara-C resulted in significant anti-tumour effect compared with respective monotherapy. Conclusion: ONO-9330547 is a highly potent dual Axl/Mer inhibitor with evidence of efficacy in AML cells. Moreover, up-regulation of Axl/Mer after chemotherapy indicates the potential combination of ONO-9330547 with standard therapy to overcome treatment resistance in AML. Additional work to investigate and clarify the involvement of Axl/Mer in other types of leukemia are currently underway. Disclosures Yasuhiro: Ono Pharmaceutical Co., Ltd.: Employment. Yoshizawa:Ono Pharmaceutical Co., Ltd.: Employment. Fujikawa:ONO Pharmaceutical Co., Ltd.: Employment. Tanaka:ONO Pharmaceutical Co., Ltd.: Employment. Koike:ONO Pharmaceutical Co., Ltd.: Employment. Kawabata:Ono Pharmaceutical Co., Ltd.: Employment.

Pemetrexed overcomes primary and secondary resistance to erlotinib in human non-small cell lung cancer (NSCLC) cell lines

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 17040-17040
Author(s):  
T. Li ◽  
Y. Ling ◽  
R. Perez-Soler
Keyword(s):  
Cell Lines ◽  
Advanced Nsclc ◽  
Single Agent ◽  
Predictive Biomarkers ◽  
Nsclc Cell ◽  
Wild Type ◽  
Secondary Resistance ◽  
Egfr Gene ◽  
Sequential Administration ◽  
Synergistic Cytotoxicity

17040 Background: Erlotinib (E) and pemetrexed (P) have proven single agent activity in advanced NSCLC after first-line chemotherapy. The presence of K-Ras or EGFR T790M mutations in NSCLC tumors has been associated with primary or secondary resistance to erlotinib. We have previously reported that sequential administration of P followed by E results in synergistic cytotoxicity in NSCLC cells that contain the wild-type EGFR gene. In this study, we evaluate the cytotoxic effects of E and P in E-resistant human NSCLC cell lines that have either EGFR or K-Ras mutations and validate predictive biomarkers for drug sensitivity. Methods: E-resistant NSCLC cell lines [H1650 (EGFRdel E746-A750), H1975 (EGFRL858R/T790M), and A549 (K-RasG12S)] were exposed to E and P continuously for 72 hrs. Combinations of E and P were compared with E or P alone. Cellular effects assayed include cell survival by cell count and MTT assay, cell cycle distribution and apoptosis by flow cytometry after propidium iodide staining, and expression of different elements of the EGFR axis by immunoblots. The degree of cytotoxic synergism was expressed by the combination index (C.I.). Results: P and E have significant cytotoxic synergism (C.I. <1) in these E-resistant NSCLC cell lines. The cytotoxic synergism is, at least in part, mediated by the inhibitory effect of E on the P-induced activation of EGFR-mediated proliferation and/or survival responses (mainly via the PI3K/AKT pathway). Sensitivity of NSCLC cells to P and E might be predicted by the ratio of (p-EGFR:EGFR) to (p-AKT:AKT), reflecting tumor dependency on the EGFR axis for growth and survival. Conclusions: Together with our previous data, we have demonstrated that the combination of P and E is synergistic in E-resistant NSCLC cell lines that have either a wild-type or mutant EGFR gene, or a mutant K-Ras gene. This combination deserves further evaluation in a clinical trial for the treatment of advanced NSCLC. No significant financial relationships to disclose.

Effect of the combination of the dual mTOR/pI3K inhibitor NVP-BEZ235 with gemcitabine on growth inhibition in pancreatic cancer cells in vitro and in vivo.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e15070-e15070
Author(s):  
Luise Maute ◽  
Johannes Wicht ◽  
Martin Zoernig ◽  
Manuel Niederhagen ◽  
Lothar Bergmann
Keyword(s):  
Pancreatic Cancer ◽  
Tumor Growth ◽  
Cell Lines ◽  
Mtor Inhibitor ◽  
Single Agent ◽  
Human Pancreatic Cancer ◽  
Pancreatic Cancer Cells ◽  
Sequential Administration

e15070 Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignant tumours and is still associated with a very poor prognosis. Therefore new treatment strategies are needed. The PI3K/AKT and mTOR signaling pathways are frequently dysregulated in PDAC. Thus we investigated the effects of NVP-BEZ235, a novel dual PI3K/mTOR inhibitor, alone or in combination with gemcitabine first in vitro and after promising results also in vivo. Methods: We examined the effect of gemcitabine and NVP-BEZ235 (kindly provided by Novartis Pharma) on cell viability as single agents and in combination with sequential administrations in the four human pancreatic cancer cell lines MiaPaCa-2, Panc-1, AsPC-1 and BxPC-3. For in vivo experiments we used NOD SCID Mice, which were injected with BxPc3 into the right flank. Treatments consisted of Gemcitabine alone, NVP-BEZ235 alone, simultaneous application of both, first application of Gemcitabine followed by NVP-BEZ235 and NVP-BEZ235 followed by Gemcitabine. Results: Simultaneous incubation of gemcitabine and NVP-BEZ235 affected the PDAC cell lines significantly better than the single agent administration. But most effective was a sequential administration of gemcitabine followed by NVP-BEZ235. In vivo Gemcitabine and NVP-BEZ235 as single agents showed a slightly reduced tumor growth and the treatment in the sequence NVP-BEZ235 first, followed by Gemcitabine resulted in only a minimal reduction of tumor growth. The most effective results were obtained by simultaneous and even better in the sequence of Gemcitabine followed by NVP-BEZ235, respectively. Conclusions: The combination of gemcitabine with the dual PI3k/mTOR inhibitor NVP-BEZ235 enhanced the efficacy of PDAC treatment via down-regulation of the DDR related gene Survivin in vitro. This combination seems to be significantly more effective than single agent use in vitro and also in vivo. Furthermore we demonstrated that the sequence of administration of these agents could be a relevant issue. These promising results might offer a new and effective option for the treatment of pancreatic cancer in the future.

scholarly journals HER3 Differentiates Basal From Claudin Type Triple Negative Breast Cancer and Contributes to Drug and Microenvironmental Induced Resistance

2020 ◽  
Vol 10 ◽  
Author(s):  
Nicoleta Sinevici ◽  
Bahar Ataeinia ◽  
Veronica Zehnder ◽  
Kevin Lin ◽  
Lauren Grove ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Lines ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Human Cancer ◽  
Single Agent ◽  
Mapk Signaling ◽  
Akt Pathway ◽  
Compensatory Mechanisms ◽  
Tnbc Cell

Triple Negative Breast Cancer (TNBC) is an aggressive form of Breast Cancer (BC). Numerous kinase inhibitors (KI) targeting different pathway nodes have shown limited benefit in the clinical setting. In this study, we aim to characterize the extent of HER3 reliance and to define the effect of Neuregulin (NRG) isoforms in TNBCs. Basal and Claudin type TNBC cell lines were treated with a range of small molecule inhibitors, in the presence or absence of the HER3 ligand NRG. Single agent and combination therapy was also evaluated in human cancer cell lines through viability and biochemical assessment of the AKT/MAPK signaling pathway. We show that Basal (BT20, HCC-70, and MDA-MB-468) and Claudin type (MDA-MB-231, BT-549) TNBC cell lines displayed differential reliance on the HER family of receptors. Expression and dynamic HER3 upregulation was predominant in the Basal TNBC subtype. Furthermore, the presence of the natural ligand NRG showed potent signaling through the HER3-AKT pathway, significantly diminishing the efficacy of the AKT and PI3K inhibitors tested. We report that NRG augments the HER3 feedback mechanism for continued cell survival in TNBC. We demonstrate that combination strategies to effectively block the EGFR-HER3-AKT pathway are necessary to overcome compensatory mechanisms to NRG dependent and independent resistance mechanisms. Our findings suggests that the EGFR-HER3 heterodimer forms a major signaling hub and is a key player in tumorigenesis in Basal but not Claudin type TNBC tested. Thus, HER3 could potentially serve as a biomarker for identifying patients in which targeted therapy against the EGFR-HER3-AKT axis would be most valuable.

A VEGFR2 Antagonist Inhibits Cell Proliferation, Migration, and Invasion by Blocking the PI3K-Akt and MAPK Signaling Pathways in Thyroid Cancer

2021 ◽  
Author(s):  
Chunhao Liu ◽  
Zhao Liu ◽  
Hao Zhao ◽  
Yue Cao ◽  
Yansong Lin ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Thyroid Cancer ◽  
Cell Lines ◽  
Mapk Signaling ◽  
Vascular Endothelial ◽  
Antitumor Effects ◽  
Invasion And Migration ◽  
And Migration ◽  
Mapk Signaling Pathways

Abstract Background: Vascular endothelial growth factor receptor-2 (VEGFR2)-mediated signaling cascades are involved in proliferation, migration, survival, and permeability changes in vascular endothelial cells. It was thought that VEGFR2 antagonists exerted their antitumor effects by inhibiting angiogenesis in tumor tissues. However, some recent studies have found that they have significant direct antitumor effects in some tumors. The aim of this study was to explore the antitumor effects and mechanisms of VEGFR2 antagonists in thyroid cancer (TC).Methods: The antitumor efficacy of a VEGFR2 antagonist (apatinib) in TC cells was evaluated through a series of in vitro experiments, and xenograft models were used to test its in vivo antitumor activity. The antitumor mechanisms of the VEGFR2 antagonist were explored using western blotting and immunohistochemistry.Results: Compared with that in the normal human thyroid cell line HTori3, the expression of VEGFR2 in TC cell lines (including IHH4, BCPAP, TPC-1, C643, K1, and 8305C) was significantly increased, especially in the C643 and 8305C cell lines. VEGFR2 antagonist inhibited the proliferation of C643 and 8305C cells in a dose-dependent manner, significantly reduced the invasion and migration of these cells, induced G0/G1 phase arrest and promoted cancer cell apoptosis. Additionally, the antiproliferative effect of the VEGFR2 antagonist was significantly reduced after KDR gene knockdown. In vivo experiments showed that tumor growth in nude mice was significantly inhibited in response to apatinib. The western blot and immunohistochemistry results showed that the VEGFR2 antagonist significantly reduced the expression and phosphorylation of VEGFR2 and further inhibited the phosphorylation of the downstream molecules Akt and ERK1/2.Conclusions: The VEGFR2 antagonist inhibited cell proliferation, invasion and migration in TC by inhibiting the PI3K/Akt and MAPK signaling pathways and exerted direct antitumor effects. Thus, directly targeting VEGFR2 can be an effective strategy for TC expressing VEGFR2.

scholarly journals SM09419, a Novel, Small-Molecule CDC-like Kinase (CLK) Inhibitor, Demonstrates Strong Inhibition of the Wnt Signaling Pathway and Antitumor Effects in FMS-like Tyrosine Kinase 3 (FLT3)-Mutant Acute Myeloid Leukemia Models

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1377-1377 ◽  
Author(s):  
Heekyung Chung ◽  
Emily Creger ◽  
Lauren Sitts ◽  
Kevin Chiu ◽  
Chi-Ching Mak ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Tumor Regression ◽  
Single Agent ◽  
Wnt Signaling Pathway ◽  
Antitumor Effects ◽  
Employment Equity ◽  
Equity Ownership

Acute myeloid leukemia (AML) with the FLT3 internal tandem duplication (FLT3-ITD) mutation accounts for ~25% of all AMLs, carries a poor prognosis, and is prone to relapse despite targeted therapy. FLT3 mutations are associated with aberrant activation of the Wnt signaling pathway, which itself is implicated in AML initiation/progression and is required for the self-renewal and survival of leukemic stem cells. CLKs regulate the activity of serine/arginine-rich splicing factors (SRSFs) that modulate spliceosome assembly, mRNA splicing, and gene expression. SM09419 is a novel, oral, small-molecule pan-CLK inhibitor that potently inhibits the Wnt pathway. These studies examined the antitumor activity of SM09419 as a single agent and in combination with targeted and standard therapies in preclinical models of FLT3-ITD AML. In MV-4-11 and MOLM-13 AML cells carrying the FLT3-ITD mutation, SM09419 dose-dependently inhibited SRSF6 phosphorylation and potently suppressed expression of Wnt pathway-related genes (CCND1, MYC, TCF7, DVL2). The effect on cell proliferation was tested in 8 AML cell lines with varying mutation profiles as well as 26 different leukapheresis-derived primary human AML cells. Proliferation was strongly impaired by SM09419 across all tested cell lines (average EC50=0.2 + 0.048 µM]); MV-4-11 and MOLM-13 cells had EC50 of 0.049 and 0.144 µM, respectively. SM09419 also potently inhibited proliferation in all primary AML cells (average EC50=0.048 + 0.0097 µM) regardless of FLT3 mutation status, cytogenetics, or AML diagnosis (de novo or relapsed/refractory). SM09419 also induced apoptosis in MV-4-11 and MOLM-13 cells, increasing caspase 3/7 activation and PARP cleavage while reducing survivin and MCL-1 expression relative to vehicle. In vivo antitumor effects and tolerability of oral SM09419 (QD) alone or combined with either midostaurin (FLT3 inhibitor) or venetoclax (BCL2 inhibitor) and/or azacitidine were assessed in FLT3-ITD xenograft models (n=5-6/group). In MOLM-13 xenografts, SM09419 (12.5 and 25 mg/kg) induced strong tumor growth inhibition (TGI) vs. vehicle at Day 14 (TGI 52% [p&lt;0.05] and 74% [p&lt;0.001], respectively). Midostaurin (50 mg/kg) induced significant TGI vs. vehicle (50%, p&lt;0.05), which was increased when administered in combination with 12.5 mg/kg SM09419 (81%, p&lt;0.001). In MV-4-11 xenografts, single-agent SM09419 (6.25, 12.5, and 25 mg/kg) induced significant TGI vs. vehicle (56% [p&lt;0.05], 94%, and 95% [p&lt;0.001], respectively) at Day 26 with tumor regression in all mice dosed at 12.5 mg/kg and 25 mg/kg. In a subsequent experiment, midostaurin (50 mg/kg) alone and combined with 6.25 mg/kg SM09419 for 23 days induced tumor regression in MV-4-11 xenografts (100% TGI vs. vehicle, p&lt;0.0001). After treatment discontinuation, tumor regression was maintained in all mice (6/6) treated with the combination for 26 days, whereas tumor regrowth was immediately observed in midostaurin-treated mice. In another MV-4-11 xenograft study, the combination of 6.25mg/kg SM09419 with azacitidine (0.8 mg/kg QD) and/or venetoclax (25 mg/kg QD) induced significant TGI (95-98% vs. vehicle, p&lt;0.001) with tumor regression at Day 26. Azacitidine + venetoclax induced 79% TGI (p&lt;0.001), but no tumor regression was observed. The triple combination induced tumor regression in all mice and complete regressions in 4/6 mice (67%); it had a greater effect on slowing tumor regrowth after treatment discontinuation vs. a single agent or doublet. SM09419 alone or in combination was well tolerated in these xenograft models based on body weight measurements. In summary, SM09419 potently inhibited SRSF6 phosphorylation and Wnt signaling pathway activity and induced apoptosis in FLT3-ITD cell lines. It also inhibited proliferation in cell lines and primary AML cells regardless of FLT3 status. The strong in vivo antitumor effects observed as combination treatment suggest that SM09419 combined with standard therapies may provide a clinical benefit by slowing or preventing relapse in AML with a marker of poor prognosis such as FLT3-ITD. A Phase 1 study assessing safety, tolerability, and pharmacokinetics of SM09419 in subjects with advanced hematologic malignancies is being initiated. Disclosures Chung: Samumed, LLC: Employment, Equity Ownership. Creger:Samumed, LLC: Employment, Equity Ownership. Sitts:Samumed, LLC: Employment, Equity Ownership. Chiu:Samumed, LLC: Employment, Equity Ownership. Mak:Samumed, LLC: Employment, Equity Ownership. KC:Samumed, LLC: Employment, Equity Ownership. Tam:Samumed, LLC: Employment, Equity Ownership. Bucci:Samumed, LLC: Employment, Equity Ownership. Stewart:Samumed, LLC: Employment, Equity Ownership. Phalen:Samumed, LLC: Employment, Equity Ownership. Cha:Samumed, LLC: Employment, Equity Ownership.

scholarly journals The Sequenced Combination of Rigosertib and Azacitidine Has Modulatory Effects on CXCL8, RIG-I like Receptor (RLR) and Wnt/β-Catenin Signaling and Downstream Hematopoiesis Pathways in an in Vitro Model of the Myelodysplastic Syndrome

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4231-4231
Author(s):  
Richa Rai ◽  
Stella Melana ◽  
Shyamala C. Navada ◽  
Rosalie Odchimar-Reissig ◽  
Erin P. Demakos ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Lines ◽  
Research Funding ◽  
Bone Marrow Failure ◽  
Single Agent ◽  
Mapk Signaling ◽  
L Cells ◽  
Clinical Resistance ◽  
Functional Pathways

Background: MDS is characterized by ineffective hematopoiesis and multiple cytopenias. Azacitidine (AZA), a hypomethylating agent (HMA), the standard therapy for higher-risk MDS patients (pts), improves hematopoiesis in 50% of MDS pts, with a median response of 14-24 months. Those pts who initially respond to AZA either relapse or progress with bone marrow failure and have a median survival of 4 to 6 months. Both primary and secondary resistance is a significant challenge and results in poor survival. Rigosertib (RIGO), a small molecule Ras mimetic, as a single agent improved hematopoiesis in 15% of MDS pts who had failed a prior HMA. In vitro data of synergy of RIGO combined with AZA that was sequence dependent (Skiddan et al. AACR 2006), led to a Phase I/II study of the combination of RIGO/AZA and demonstrated an overall response rate of 90% in HMA naïve and 54% in HMA failures pts (Navada et al. ASH 2018). Restoration of functional hematopoiesis in response to treatment with AZA when combined with RIGO in pts, who had failed an HMA, is a unique observation in overcoming the HMA clinical resistance phenotype. Elucidating mechanisms leading to restoration of HMA effects on hematopoiesis could have profound clinical benefit. Methods: We investigated the molecular mechanisms in response to AZA and RIGO either alone or in sequential combinations (SC) in vitro. Pathway specific real time PCR (QPCR) for epigenetic modification genes, hematopoiesis signaling genes, interferon signaling genes, MAPK signaling genes and antiviral response genes was performed in MDS-L (AZA sensitive) as well asBW-90 (AZA resistant) cell lines treated with RIGO, AZA and SC. Functional analysis was performed using Ingenuity pathway analysis (IPA) software. Reverse phase protein array (RPPA) was also performed on the MDS-L and BW-90 cell lines treated with AZA and RIGO alone and SCs for the validation. Results: We observed differential expression (DE) pattern of the genes in response to AZA, RIGO and their SCs both in MDS-L and BW-90 cell lines. The functional pathways associated with DE genes predominantly impacts RIG-I like receptor (RLR) signaling (anti-viral defense pathway), T cell exhaustion signaling, Wnt/β-catenin signaling and hematopoiesis pathway in MDS-L cells treated with RIGO/AZA combinations compared to other treatments (Table 1, Fig 1A). However, RIGO alone induces the dysregulation of RIG-I like receptor signaling and T cell exhaustion signaling in BW-90 cells (Table 1, Fig A). Expression of CXCL8 was observed to be elevated in RIGO and SCs by 7-9 fold compared to untreated MDS-L cells while no significant difference was found in response to any treatment in BW-90 cells (Fig 1B). CXCL8 is a RLR signaling responsive gene and is also one of the genes which were observed to be involved in hematopoiesis signaling identified by pathway enrichment analysis. Similar to QPCR data we observed striking differences in MDS-L and BW-90 cells in response to different treatments at protein level and functional pathways by RPPA analysis and IPA, respectively. RIGO is a RAS mimetic and interrupts RAS-RAF binding (Reddy et al ASH 2014), in this study we observed RIGO in combination with AZA inhibits several MAPK signaling pathways including PI3K/AKT/mTOR, ERK/MAPK and p38 MAPK signaling in MDS-L cells. RIGO had been reported to inhibit PI3K/AKT pathway as a single agent (Xu et al. Sci Rep 2014). In addition, Wnt/β-catenin pathway was predicted to be specifically activated in MDS-L cells with SCs. Both QPCR and RPPA results demonstrated activation of Wnt/β-catenin signaling pathway in response to RIGO alone and the combination with AZA. Importantly, expression of two genes Jun (proto oncogene) and CD44 (Wnt target gene) that are associated with the Wnt/β-catenin signaling pathway were upregulated at both mRNA (Fig 1C) and protein level (Fig 1D) which suggests a crucial role of RIGO in wnt signaling. Conclusions: These data demonstrate that RIGO sequenced with AZA upregulates RLR, Wnt/β-catenin and hematopoiesis signaling. Involvement of CXCL8 (RLR responsive gene) and activation of wnt signaling genes suggests their linkage to hematopoiesis. Further studies are underway to determine the effects of these signaling pathways on improving hematopoiesis both in vitro and in vivo in the HMA clinical resistance setting to identify potential therapeutic targets to reverse bone marrow failure in pts with HMA resistance. Disclosures Navada: Onconova Therapeutics Inc: Research Funding. Reddy:Onconova Therapeutics Inc: Equity Ownership, Research Funding. Silverman:Medimmune: Research Funding; Onconova Therapeutics Inc: Patents & Royalties, Research Funding; Celgene: Research Funding.

FIH phase I dose escalation study of FN1501, an investigational FLT-3 inhibitor with multiple targets in patients with relapsed or refractory solid tumors and acute myeloid leukemia.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e15656-e15656
Author(s):  
Gary Edward Richardson ◽  
Ulka N. Vaishampayan ◽  
Viviana Bozon ◽  
Ai-Min Hui ◽  
Stephen K. Williamson
Keyword(s):  
Acute Myeloid Leukemia ◽  
Solid Tumors ◽  
Cell Lines ◽  
Tyrosine Kinases ◽  
Myeloid Leukemia ◽  
Single Agent ◽  
Leukemia Cell ◽  
Post Dose ◽  
Leukemia Cell Lines ◽  
Acute Myeloid

e15656 Background: FN1501 inhibits various tyrosine kinases as CDK4/6, KIT, PDGFR, ALK and RET proteins, particularly potent on FLT3 and EGFR2. A Ph1 FIH trial for patients (pts) with solid tumors and Acute Myeloid Leukemia (AML) is on-going1. Preclinical data showed that FN1501 inhibits the phosphorylation of FLT3 and its downstream kinase STAT5 in human acute leukemia cell lines, arrests the cell cycle inducing apoptosis and inhibits growth and proliferation of leukemia cells. It has anti-proliferation activity against other leukemia cell lines bearing FLT3 mutations, and lymphoma cell lines2, 3. Methods: 26 pts with advanced solid tumors or AML enrolled in the escalation phase and received IV FN1501 on days 1, 3, 5, 8, 10 and 12 on 21-day cycles. Primary objectives are safety and MTD, secondary objectives include preliminary activity, PK and PD. Plasma PK were assessed at different timepoints pre and post dose in C1 and C2. Results: As of 6FEB20, 26 pts have been treated in 7 ascending doses of 2.5mg, 5mg, 10mg, 15mg, 22.5mg, 30mg and 40mg. A 54 mg dose cohort is on-going. No DLTs, no SAEs or deaths associated to FN1501 have been reported. 12 pts (46%) had one grade 3 or higher TEAE and 7 pts (27%) had dose interruptions due to a TEAE. Administration of FN1501 to pts with metastatic solid tumors has resulted in anti-tumor activity. 9 pts had durable stable disease across 4 doses in renal, endometrial, ovarian, gastric, appendix and thymic malignancies. One pt with serous endometrial carcinoma achieved a cPR after 2 cycles at 40mg with a 47% tumor size reduction (target lesions). As of 26Oct19 preliminary PK data showed a t1/2 of approximately 12.7-19.0 hours post-dose. Mean Cmax and AUC increased proportionally with dose and Clearance is consistent among all doses. Conclusions: This on-going Ph1trial of FN1501 is providing evidence of dose or exposure effects as a single agent in patients with solid tumors. Since FN1501 targets multiple kinases on addition to FLT3, antitumor activity beyond AML is also being observed, suggesting that the potent inhibitory effects of other tyrosine kinases, including EGFR2 may be playing a role in the regulation of cellular functions, cell growth, differentiation and angiogenesis effects. FN1501 has been well tolerated and AEs are manageable. Genomic alterations investigations are underway to identify candidate biomarkers useful for predicting sensitivity to the multiple FN1501 tyrosine kinases. Further development of FN1501 is warranted. Clinical trial information: NCT03690154.

scholarly journals Combination effect of lapatinib with foretinib in HER2 and MET co-activated experimental esophageal adenocarcinoma

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Md. Sazzad Hassan ◽  
Fiona Williams ◽  
Niranjan Awasthi ◽  
Margaret A. Schwarz ◽  
Roderich E. Schwarz ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Cell Line ◽  
Esophageal Adenocarcinoma ◽  
Cell Lines ◽  
Tyrosine Kinases ◽  
Single Agent ◽  
Survival Models ◽  
Her2 Positive

AbstractRecent studies have demonstrated that HER2 and MET receptor tyrosine kinases are co-overexpressed in a subset esophageal adenocarcinoma (EAC). We therefore studied the usefulness of combining HER2 and MET targeting by small-molecule inhibitors lapatinib and foretinib, respectively, both in in-vitro and in-vivo models of experimental EAC. We characterized MET and HER2 activation in a panel of human EAC cell lines, and the differential susceptibility of these EAC cell lines to single agent or combination of foretinib and lapatinib. We then explored the antitumor efficacy with survival advantage following foretinib and lapatinib monotherapy and in combination in murine subcutaneous xenograft and peritoneal metastatic survival models of human EAC. The OE33 EAC cell line with strong expression of phosphorylated both MET and HER2, demonstrated reduced sensitivity to foretinib and lapatinib when used as a single agent. The co-administration of foretinib and lapatinib effectively inhibited both MET and HER2 phosphorylation, enhanced inhibition of cell proliferation and xenograft tumor growth by inducing apoptosis, and significantly enhanced mouse overall survival, overcoming single agent resistance. In the OE19 EAC cell line with mainly HER2 phosphorylation, and the ESO51 EAC cell line with mainly MET phosphorylation, profound cell growth inhibition with induction of apoptosis was observed in response to single agent with lack of enhanced growth inhibition when the two agents were combined. These data suggest that combination therapy with foretinib and lapatinib should be tested as a treatment option for HER2 positive patients with MET-overexpressing EAC, and could be a novel treatment strategy for specific EAC patients.

scholarly journals SM09419, a Novel, Small-Molecule CDC-like Kinase (CLK) Inhibitor, Demonstrates Strong Inhibition of the Wnt Signaling Pathway and Antitumor Effects in Tumor Protein p53 (TP53)-Mutant Acute Myeloid Leukemia Models

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3913-3913
Author(s):  
Heekyung Chung ◽  
Emily Creger ◽  
Lauren Sitts ◽  
Kevin Chiu ◽  
Chi-Ching Mak ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Cell Lines ◽  
Tumor Regression ◽  
Single Agent ◽  
Wnt Signaling Pathway ◽  
Antitumor Effects ◽  
Employment Equity ◽  
Equity Ownership ◽  
Induced Apoptosis

Acute myeloid leukemia (AML) with TP53 mutation makes up ~13% of AML cases and is an aggressive, treatment-resistant subtype with dismal prognosis and limited therapeutic options. Aberrant activation of the Wnt signaling pathway is associated with AML initiation/progression and is required for the self-renewal and survival of leukemic stem cells, making Wnt signaling inhibition a potential therapeutic modality for adverse AML. CLKs regulate the activity of serine/arginine-rich splicing factors (SRSFs) that modulate spliceosome assembly, mRNA splicing, and gene expression. SM09419 is a novel, oral, small-molecule pan-CLK inhibitor that potently inhibits the Wnt pathway in a Wnt signaling reporter assay. The purpose of these studies was to examine the antitumor activity of SM09419 as a single agent and in combination with standard therapies in preclinical models of TP53 mutant (TP53mut) AML. In TF-1a and KG-1a AML cells with TP53 mutations, SM09419 dose-dependently inhibited SRSF6 phosphorylation and potently suppressed expression of Wnt-related genes (LEF1, MYC, DVL2) and proteins vs. vehicle. The effect of SM09419 on cell proliferation was tested in 6 TP53mut AML cell lines. Proliferation was strongly impaired by SM09419 across all cell lines (EC50=0.23 + 0.056 µM). SM09419 significantly induced apoptosis in TF-1a and KG-1a cells, increasing caspase 3/7 activation and PARP cleavage while reducing survivin and MCL-1 expression relative to vehicle. In addition, SM09419 potently inhibited cell proliferation when tested in 27 leukapheresis-derived human primary AML cell lines (EC50=0.046 + 0.0061 µM) regardless of TP53 status, cytogenetics, or AML diagnosis (de novo or relapsed/refractory). In vivo antitumor effects and tolerability of oral SM09419 (QD) alone or combined with cytarabine (Ara-C), venetoclax (VEN), or azacytidine (AZA) were assessed in mice bearing TP53mut flank xenografts (n=5-15/group). In TF-1a xenografts, SM09419 (12.5 and 25 mg/kg) induced significant tumor growth inhibition (TGI) vs. vehicle at D20 (TGI 55-56% [p<0.01]). VEN (50mg/kg) was not effective (3% TGI) and combining VEN with SM09419 had no additional benefit (52%-60% TGI). In Kasumi-1 xenografts, SM09419 (12.5 and 25 mg/kg), AZA (0.8 mg/kg), and VEN (25 mg/kg) induced TGI vs. vehicle of 87%, 95% (both p<0.0001), 72% (p<0.001), and 48% (NS), respectively at D18. SM09419 25 mg/kg alone induced tumor regression in 40% (2/5) of the mice. SM09419 (12.5 mg/kg) + VEN induced greater TGI vs. vehicle (96%, p<0.0001) with tumor regression in 80% (4/5) of the mice, while AZA + VEN induced 79% TGI (p<0.001) with no tumor regression. In KG-1a xenografts, single-agent SM09419 (12.5 and 25 mg/kg) and Ara-C (10mg/kg) induced significant TGI vs. vehicle (53%, 98%, and 80% [p<0.001], respectively) at D28 but VEN (12.5mg/kg) did not (35% TGI). The combination of SM09419 (12.5 mg/kg) + VEN (12.5 mg/kg) improved TGI (98%) vs. vehicle. Tumor regression was seen in all mice with single-agent SM09419 (25 mg/kg) and 12.5 mg/kg + VEN. In another KG-1a xenograft study, mice were treated with combinations of SM09419 (12.5 mg/kg), AZA (0.8 mg/kg), and VEN (25 mg/kg) for 20 days followed by 21 days of SM09419 (25 mg/kg) or vehicle maintenance in some groups. SM09419 + VEN, SM09419 + AZA, and AZA + VEN induced TGI of 95%, 64%, and 58%, respectively (all p<0.0001), with 80% (12/15) regression in SM09419 + VEN. The triplet induced 91% TGI but was not well tolerated due to GI toxicity. In the maintenance phase, SM09419 given QD or QOD greatly slowed tumor regrowth vs. vehicle at D41 in mice previously treated with SM09419 + VEN (80% and 72% TGI [p<0.001], respectively). SM09419 QD maintenance therapy also slowed tumor regrowth following AZA + VEN (p<0.0001). SM09419 alone and in combination (except with AZA + VEN) was well tolerated in all tested xenografts. In summary, SM09419 potently inhibited SRSF phosphorylation and Wnt pathway signaling and induced apoptosis in TP53mut AML cell lines. It also inhibited proliferation in cell lines and primary AML cells regardless of TP53 status. Strong in vivo antileukemic effects were observed with SM09419 as a single agent or in combination with other AML therapies, suggesting that it is a potential treatment for hard-to-treat AML subtypes such as TP53mut AML. A Phase 1 study assessing safety, tolerability, and pharmacokinetics of SM09419 in subjects with advanced hematologic malignancies is being initiated. Disclosures Chung: Samumed, LLC: Employment, Equity Ownership. Creger:Samumed, LLC: Employment, Equity Ownership. Sitts:Samumed, LLC: Employment, Equity Ownership. Chiu:Samumed, LLC: Employment, Equity Ownership. Mak:Samumed, LLC: Employment, Equity Ownership. KC:Samumed, LLC: Employment, Equity Ownership. Tam:Samumed, LLC: Employment, Equity Ownership. Bucci:Samumed, LLC: Employment, Equity Ownership. Stewart:Samumed, LLC: Employment, Equity Ownership. Phalen:Samumed, LLC: Employment, Equity Ownership. Cha:Samumed, LLC: Employment, Equity Ownership.

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