scholarly journals A Novel 2-Carbon-Linked Dimeric Artemisinin With Potent Antileukemic Activity and Favorable Pharmacology

2022 ◽  
Vol 11 ◽  
Author(s):  
Amanda B. Kagan ◽  
Blake S. Moses ◽  
Bryan T. Mott ◽  
Ganesha Rai ◽  
Nicole M. Anders ◽  
...  
Keyword(s):  
Myeloid Leukemia ◽  
Antimalarial Activity ◽  
Single Agent ◽  
Therapeutic Window ◽  
Antileukemic Activity ◽  
Standard Chemotherapy ◽  
The Past ◽  
Or Gene ◽  
Cure Rates

Acute myeloid leukemia (AML) remains a devastating disease, with low cure rates despite intensive standard chemotherapy regimens. In the past decade, targeted antileukemic drugs have emerged from research efforts. Nevertheless, targeted therapies are often effective for only a subset of patients whose leukemias harbor a distinct mutational or gene expression profile and provide only transient antileukemic responses as monotherapies. We previously presented single agent and combination preclinical data for a novel 3-carbon-linked artemisinin-derived dimer (3C-ART), diphenylphosphate analog 838 (ART838), that indicates a promising approach to treat AML, given its demonstrated synergy with targeted antileukemic drugs and large therapeutic window. We now report new data from our initial evaluation of a structurally distinct class of 2-carbon-linked dimeric artemisinin-derived analogs (2C-ARTs) with prior documented in vivo antimalarial activity. These 2C-ARTs have antileukemic activity at low (nM) concentrations, have similar cooperativity with other antineoplastic drugs and comparable physicochemical properties to ART838, and provide a viable path to clinical development.

scholarly journals First-in-Human Phase I Study of Iadademstat (ORY-1001): A First-in-Class Lysine-Specific Histone Demethylase 1A Inhibitor, in Relapsed or Refractory Acute Myeloid Leukemia

2020 ◽  
Vol 38 (36) ◽  
pp. 4260-4273
Author(s):  
Olga Salamero ◽  
Pau Montesinos ◽  
Christophe Willekens ◽  
José Antonio Pérez-Simón ◽  
Arnaud Pigneux ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Phase I ◽  
Myeloid Leukemia ◽  
Single Agent ◽  
Antileukemic Activity ◽  
Open Label ◽  
Refractory Acute Myeloid Leukemia ◽  
Acute Myeloid

PURPOSE Iadademstat is a novel, highly potent, and selective inhibitor of LSD1 (KDM1A), with preclinical in vitro and in vivo antileukemic activity. This study aimed to determine safety and tolerability of iadademstat as monotherapy in patients with relapsed/refractory acute myeloid leukemia (R/R AML). METHODS This phase I, nonrandomized, open-label, dose-escalation (DE), and extension-cohort (EC) trial included patients with R/R AML and evaluated the safety, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary antileukemic activity of this orally bioavailable first-in-class lysine-specific demethylase 1 inhibitor. RESULTS Twenty-seven patients were treated with iadademstat on days 1 to 5 (5-220 µg/m2/d) of each week in 28-day cycles in a DE phase that resulted in a recommended dose of 140 µg/m2/d of iadademstat as a single agent. This dose was chosen to treat all patients (n = 14) in an EC enriched with patients with MLL/KMT2A-rearranged AML. Most adverse events (AEs) were as expected in R/R AML and included myelosuppression and nonhematologic AEs, such as infections, asthenia, mucositis, and diarrhea. PK data demonstrated a dose-dependent increase in plasma exposure, and PD data confirmed a potent time- and exposure-dependent induction of differentiation biomarkers. Reductions in blood and bone marrow blast percentages were observed, together with induction of blast cell differentiation, in particular, in patients with MLL translocations. One complete remission with incomplete count recovery was observed in the DE arm. CONCLUSION Iadademstat exhibits a good safety profile together with signs of clinical and biologic activity as a single agent in patients with R/R AML. A phase II trial of iadademstat in combination with azacitidine is ongoing (EudraCT No.: 2018-000482-36).

scholarly journals MDM2 inhibitor APG-115 exerts potent antitumor activity and synergizes with standard-of-care agents in preclinical acute myeloid leukemia models

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Douglas D. Fang ◽  
Qiuqiong Tang ◽  
Yanhui Kong ◽  
Tao Rong ◽  
Qixin Wang ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Single Agent ◽  
Standard Of Care ◽  
Tumor Burden ◽  
Antileukemic Activity ◽  
Medical Needs ◽  
Mdm2 Inhibitor ◽  
Acute Myeloid

AbstractAcute myeloid leukemia (AML) is a clinically and genetically heterogeneous clonal disease associated with unmet medical needs. Paralleling the pathology of other cancers, AML tumorigenesis and propagation can be ascribed to dysregulated cellular processes, including apoptosis. This function and others are regulated by tumor suppressor P53, which plays a pivotal role in leukemogenesis. Opposing P53-mediated activities is the mouse double minute 2 homolog (MDM2), which promotes P53 degradation. Because the TP53 mutation rate is low, and MDM2 frequently overexpressed, in patients with leukemia, targeting the MDM2-P53 axis to restore P53 function has emerged as an attractive AML treatment strategy. APG-115 is a potent MDM2 inhibitor under clinical development for patients with solid tumors. In cellular cultures and animal models of AML, we demonstrate that APG-115 exerted substantial antileukemic activity, as either a single agent or when combined with standard-of-care (SOC) hypomethylating agents azacitidine (AZA) and decitabine (DAC), or the DNA-damaging agent cytarabine (Ara-C). By activating the P53/P21 pathway, APG-115 exhibited potent antiproliferative and apoptogenic activities, and induced cell cycle arrest, in TP53 wild-type AML lines. In vivo, APG-115 significantly reduced tumor burden and prolonged survival. Combinations of APG-115 with SOC treatments elicited synergistic antileukemic activity. To explain these effects, we propose that APG-115 and SOC agents augment AML cell killing by complementarily activating the P53/P21 pathway and upregulating DNA damage. These findings and the emerging mechanism of action afford a sound scientific rationale to evaluate APG-115 (with or without SOC therapies) in patients with AML.

Efficacy and safety of aspacytarabine (BST-236) as a single-agent, first-line therapy for patients with acute myeloid leukemia unfit for standard chemotherapy.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 7007-7007
Author(s):  
Jessica K. Altman ◽  
Jamie Koprivnikar ◽  
James K. McCloskey ◽  
Vamsi Kota ◽  
Olga Frankfurt ◽  
...  
Keyword(s):  
Myeloid Leukemia ◽  
De Novo ◽  
Single Agent ◽  
Newly Diagnosed ◽  
Efficacy And Safety ◽  
First Line ◽  
Standard Chemotherapy ◽  
First Line Therapy ◽  
Line Therapy ◽  
De Novo Aml

7007 Background: Aspacytarabine (BST-236) is a prodrug of cytarabine, the backbone of acute myeloid leukemia (AML) standard of care chemotherapy, associated with toxicity which precludes its administration in older patients and patients with comorbidities. Aspacytarabine is inactive in its intact prodrug form until cytarabine is gradually released at pharmacokinetics which decrease the systemic exposure to peak toxic cytarabine levels, resulting in reduced systemic toxicity and relative sparing of normal tissues, enabling therapy with high cytarabine doses to patients otherwise unfit to receive it. Methods: A phase 2b open-label, single-arm study to evaluate the efficacy and safety of aspacytarabine as a first-line single-agent therapy in newly-diagnosed AML patients unfit for standard chemotherapy (NCT03435848). Aspacytarabine is administrated at 4.5 g/m2/d (containing 3 g/m2/d cytarabine) in 1-2 induction and 1-3 consolidation courses, each consisting of 6 daily 1-hour infusions. Patients with secondary AML, prior hypomethylating agent (HMA) therapy, and therapy-related AML, are eligible. Results: To date, in the ongoing study, 46 newly-diagnosed AML patients unfit for standard chemotherapy (median age 75 years) were treated with aspacytarabine and completed 1-4 courses of 4.5 g/m2/d aspacytarabine, including 26 patients (63%) with de novo AML and 17 (37%) with secondary AML. Six patients (13%) were previously treated with HMA (median 12 courses). The baseline median bone marrow blasts was 52%, and 54% and 29% of patients had adverse or intermediate European LeukemiaNet (ELN) score, respectively. Twenty (43%) patients had ECOG 2. Aspacytarabine is safe and well-tolerated in repeated-course administration. Grade > 2 drug-related adverse events include mainly hematological events and infections. The 30-day mortality rate is 11%. Of 43 patients evaluable for efficacy analysis to date, 15 patients (35%) reached a complete remission (CR) following 1 (13 patients) or 2 (2 patients) induction courses, all with complete hematological recovery (median 27.5 days, range 22-39 days). The CR rates in de novo AML patients and patients with adverse ELN score are 46% and 33%, respectively. Of the 11 patients evaluable to date for minimal residual disease (MRD) flow cytometry test, 8 are MRD negative (73%). While aspacytarabine treatment consists of a limited number of courses, median duration of response and median overall survival for responders are not reached at 12 and 24 months, respectively (end of follow up). Updated results will be presented at the meeting. Conclusions: The cumulative clinical data suggest that aspacytarabine, a time-limited single-agent treatment, is safe and efficacious as a first-line therapy for patients who are unfit for intensive chemotherapy, which may establish it as a new tolerable AML chemotherapy backbone. Clinical trial information: NCT03435848.

Autophagy Promotes the Survival and Therapy Resistance of Human Acute Myeloid Leukemia Cells Under Hypoxia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2236-2236 ◽  
Author(s):  
Dirkje W Hanekamp ◽  
Megan K Johnson ◽  
Scott Portwood ◽  
Joshua Acklin ◽  
Eunice S. Wang
Keyword(s):  
Flow Cytometry ◽  
Cell Death ◽  
Acute Myeloid Leukemia ◽  
Tyrosine Kinase Inhibitor ◽  
Myeloid Leukemia ◽  
Kinase Inhibitor ◽  
Single Agent ◽  
Xenograft Models ◽  
Acute Myeloid

Abstract Background: Acute myeloid leukemia (AML) is an aggressive hematological malignancy occurring primarily in older adults. Despite high remission rates following upfront therapy, the disease eventually recurs in most patients, and overall cure rates remain only 20-30%. Preclinical studies have recently demonstrated that the marrow microenvironment in acute leukemic hosts to be intrinsically hypoxic, with AML progression associated with further hypoxia. Moreover, human AML cells and primary AML colonies cultured under hypoxia are markedly less sensitive to cytarabine chemotherapy than normoxic cells. We hypothesized that AML cells may respond to hypoxic stress and mediate chemoresistance in part by invoking autophagy, a highly regulated catabolic process by which cells evade apoptosis by degrading damaged cellular components. To test our hypothesis, we investigated the effects of two known autophagy inhibitors (bafilomycin A1 (Baf) and chloroquine (CQ)) on the sensitivity of human AML cells to various therapeutic agents under differing oxygen levels. Methods: We treated HEL (FLT-3 wildtype) and MV4-11 (FLT-3 ITD mutant) AML cells with autophagy inhibitors (Baf and CQ) alone and in combination with a chemotherapeutic drug (cytarabine (AraC), doxorubicin (Dox), decitabine (Dac)) or a tyrosine kinase inhibitor (sorafenib, SFN) under normoxic (21% O2) or hypoxic (1% O2) conditions. Apoptosis /cell death and proliferation were measured by flow cytometry for Annexin-PI and MTT assays, respectively. Autophagy was assessed by flow cytometry using Cyto-ID Green Dye (Enzo Life Sciences), fluorescent microscropy for acridine orange dye accumulation, and western blot analysis. Results: Autophagy in human ALL and AML cell lines was significantly increased following 24-72 hours of hypoxia (1% O2) as compared with normoxia and was a relatively late response to prolonged low oxygen levels (> 24 hours). Treatment with cytotoxic agents (AraC or Dox) or hypomethylating agent (Dac) resulted in a dose-dependent increases in the number of autophagic vesicles in AML cells consistent with autophagy induction. Low-doses of Baf which selectively inhibits the vacuolar H+ ATPase to prevent lysosomal acidification, and CQ, which blocks lysosome-autophagosome fusion by raising the pH of lysosomes and endosomes, both resulted in buildup of autophagic vesicles by flow cytometry consistent with inhibition of autophagic flux in human AML cells. Combination treatment with an autophagy inhibitor (Baf, CQ) and cytotoxic chemotherapy (AraC, Dox) significantly enhanced apoptosis and cell death over single agent therapy. Treatment with Baf combined with hypomethylating therapy (Dac) synergistically improved the anti-leukemic effects as compared with monotherapy (CI 0.09-0.31)(see Figure). The addition of Baf also improved cell death induced by sorafenib (SFN) on FLT-3 ITD mutant human AML cells (MV4;11) (CI 0.36-0.9) (see Figure). Single agent Baf or CQ treatment resulted in significantly higher levels of apoptosis and cell death in AML cells under hypoxia. The anti-tumor activity of almost all combination regimens was consistently improved under hypoxic versus normoxic culture conditions. In vivo CQ treatment (25-50 mg/kg i.p. daily) in preclinical human AML xenograft models significantly inhibited systemic leukemia progression as a single agent. Further experiments investigating the in vivo effects of CQ combined with other chemotherapeutic agents in preclinical AML xenograft models are ongoing. Conclusions: Our data suggest that human AML cells preferentially induce autophagy to promote survival under chronic hypoxia and following cytotoxic, hypomethylating, and FLT-3 tyrosine kinase inhibitor therapy. Strategies targeting autophagy therefore may have the potential to improve therapeutic responses and overcome chemoresistance of AML cells within the hypoxic bone marrow microenvironment. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

scholarly journals A Phase I Study of Allogeneic Natural Killer Cell Therapy Generated from Cord Blood Hematopoietic Stem and Progenitor Cells in Elderly Acute Myeloid Leukemia Patients

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1357-1357 ◽  
Author(s):  
Harry Dolstra ◽  
Mieke W.H. Roeven ◽  
Jan Spanholtz ◽  
Basav Hangalapura ◽  
Marleen Tordoir ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Therapy ◽  
Nk Cells ◽  
Myeloid Leukemia ◽  
Nk Cell ◽  
Residual Disease ◽  
Standard Chemotherapy ◽  
Donor Chimerism ◽  
Elderly Aml

Abstract Introduction Elderly acute myeloid leukemia (AML) patients have a poor prognosis due to high relapse rates following standard therapy. Natural Killer (NK) cell alloreactivity has found to control relapse in AML in the HLA-mismatched haploidentical allogeneic stem cell transplantation (allo-SCT) setting. Moreover, allogeneic NK cell infusions can induce complete remission (CR) inpatients with advanced AML. As a consequence, adoptive NK cell transfer may be a promising treatment for elderly AML patients, who are not eligible for allo-SCT. Most clinical studies exploited NK cell products enriched from leukapheresis of haploidentical donors containing low numbers of T cells that could have contributed to the observed therapeutic effects and potentially induced graft-versus-host disease (GVHD). Therefore, we have developed a GMP-compliant culture system for the generation of large batches of NK cells from umbilical cord blood (UCB)-derived CD34+ progenitor cells, without T cell contamination. Here, we report results of a phase I dose escalation study (Dutch Trial Register nr. NTR2818) to evaluate the feasibility, safety and toxicity of allogeneic UCB-NK cell infusion following an immunosuppressive preparative regimen in elderly AML patients. Secondary endpoints were NK cell lifespan and the effects on minimal residual disease (MRD). Methods Elderly AML patients not eligible for allo-SCT, and in morphologic CR after standard therapy, were given preparative chemotherapy consisting of Cyclophosphamide (Cy;900 mg/m2/day) and Fludarabine (Flu;30 mg/m2/day) on days -6 to -2. At day 0, UCB-NK cells at a dose of 3, 10 or up to 30x106/kg body weight were infused without IL-2 treatment to study if in vivo expansion could be obtained without IL-2 support. Patients were assessed for toxicity and GVHD. Donor chimerism was measured by Q-PCR for discriminating DNA polymorphisms. NK cell expansion and phenotype were analyzed by flow cytometry. MRD was evaluated by flow cytometry and molecular techniques. Results Twelve AML patients (68-76 years) have been included, all in morphologic CR after 2 to 3 standard chemotherapy courses (n=6), or 1 standard chemotherapy course followed by subsequent treatment with hypomethylating agents (azacitidine or decitabine) (n=6). Patients were treated with Cy/Flu and an escalating dose of partially HLA-matched UCB-NK cells. Four patients had good/intermediate risk, 4 poor risk and 4 very poor risk AML. To date, 9 patients received NK cell products containing a median of 74% highly activated CD56+ NK cells, with <1x104/kg CD3+ T cells and <3x105/kg CD19+ B cells. Remaining non-NK cells were CD14+ and/or CD15+ monocytic and myelocytic cells. Follow up did not show GVHD or toxicity attributed to the NK cells. As expected, preparative Cy/Flu induced a neutropenic period of 20 ± 16 days, but no severe infections were seen. A temporary repopulation and persistence of UCB-NK cells could be detected in peripheral blood between days 1 and 8 post-infusion, which was associated with increased IL-15 plasma levels observed in most patients. Interestingly, donor chimerism increased with higher doses of infused UCB-NK cells, and donor chimerism up to 3.5% was found in bone marrow (BM) at day 7/8. Further UCB-NK cell maturation in vivo was observed by acquisition of CD16 and KIRs, while expression of activating receptors was sustained. Of the 9 treated patients so far, 5 (56%) are still in CR after 43, 35, 31, 5 and 4 months, whereas 4 patients relapsed after 5, 6 (2 pts) and 15 months. Despite morphologic CR during azacitidine treatment, residual disease of 6-7% with a leukemia-associated phenotype could be detected by flow cytometry before NK cell infusion in BM of two patients. In both patients MRD was reduced to less than 0.05% at 90 days after UCB-NK cell therapy following Flu/Cy conditioning. Conclusion These results show that GMP-compliant UCB-NK cell products containing up to 30x106 NK cells/kg body weight can be safely infused in non-transplant eligible AML patients following immunosuppressive chemotherapy. After infusion, UCB-NK cells repopulate, mature and migrate to BM without supporting IL-2 infusion. Since we observed reduction in MRD in patients on treatment with hypomethylating agents, this UCB-NK cell therapy may induce or sustain CR in elderly AML patients, and could serve as an alternative consolidation therapy for patients with refractory AML or provide bridge to allo-SCT. Disclosures Spanholtz: Glycostem Therapeutics: Employment. Tordoir:Glycostem Therapeutics: Employment. Bohme:Glycostem Therapeutics: Employment. Kok:Glycostem Therapeutics: Employment.

scholarly journals AB8939, a Microtubule-Destabilizing Agent with Potential to Overcome Multidrug Resistance, Is Active across the Range (M0-M7) of Acute Myeloid Leukemia Subtypes

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5154-5154
Author(s):  
Armelle Goubard ◽  
Martine Humbert ◽  
Colin Mansfield ◽  
Olivier Hermine ◽  
Patrice Dubreuil ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Ex Vivo ◽  
Single Agent ◽  
Proof Of Concept ◽  
Tubulin Inhibitor ◽  
French American British ◽  
Acute Megakaryocytic Leukemia ◽  
Acute Myeloid

Compound AB8939 is a structurally novel, small chemical molecule, synthesized tubulin inhibitor that can circumvent two of the major resistance mechanisms in acute myeloid leukemia (AML), namely P-glycoprotein (Pgp) and myeloperoxidase (MPO) mediated resistance, thereby conferring an important advantage over traditional tubulin inhibitors. A series of ex vivo and in vivo studies provide proof-of-concept that AB8939 has broad anti-proliferative activity across the breath of acute myeloid leukemia (AML) subtypes, i.e. M0 through M7 of the French-American-British AML classification. Acute myeloid leukemia blasts were isolated from patients' peripheral blood and/or bone marrow samples, collected either at the time of diagnosis or following relapse, and also from patient derived xenograft (PDX) models. After purification, mononuclear cells were treated for 48 hours with various concentrations of AB8939 or cytarabine (Ara-C) and analyzed in a cell proliferation/viability assay. AB8939 produced a strong anti-proliferative action against blasts isolated from AML patients with a majority of IC50 values ranging from 1.4 nM to 1.0 µM. Two-thirds of AML patients had nanomolar sensitivity to AB8939 (IC50 ≤ 500 nM), while 44% where very sensitive (IC50 ≤ 100 nM) and 11% were highly sensitive (IC50 ≤ 10 nM). The potential of AB8939 to overcome Ara-C-resistance was also evident with 66% of Ara-C-resistant blasts (i.e. IC50 >5 µM) being sensitive to AB8939. Notably, AB8939 demonstrated activity across the entire spectrum of AML subtypes, according to the French-American-British (FAB) AML classification, with an IC50 of < 50 nM in M0, M1, M4, M5 and M6 subtypes, corresponding to over 90% of the AML patient population. A slightly lower sensitivity was observed for the M3 subtype (IC50 = 1.25 µM). Additionally, potent AB8939 activity was also seen in Ara-C-insensitive biphenotypic and mixed-phenotype acute leukemia samples. All FAB categories other than M7 were tested in the abovementioned ex vivo assessment. Acute megakaryocytic leukemia (FAB AML subtype M7) is a rare form of adult AML, accounting for only 1% of cases, and is associated with resistance to standard treatment and poor prognosis. The effect of AB8939 in this subtype was assessed in vivo using an AMKL26 model, an NSG mouse model based on cells isolated from a patient with an aggressive acute megakaryocytic leukemia presenting the ETO2-GLIS2 fusion oncogene. Following post graft detection of blasts, single agent AB8939 was administered intravenously at a dose of 2 mg/kg for three consecutive days per week (3 ON / 4 OFF) for 2 weeks and then at 5 mg/kg for three consecutive days per week (3 ON / 4 OFF) for 1 week. At the end of the 3-week treatment period, blast detection in bone marrow was performed via bioluminescence imaging with comparison to vehicle-treated controls. As seen in the figure below, single agent AB8939 showed strong anti-leukemic activity in this AMKL26 mouse model as evidenced by the near eradication of blasts. No blasts could be detected in 6 out of 8 mice treated with AB8939. At the described dosing schedule, AB8939 was well-tolerated with no toxicity-related deaths and no impact on animal body weight or behavior. These findings provide preclinical proof of concept for the development of AB8939 as a next-generation tubulin inhibitor for AML, in particular for poor-prognosis AML subsets and relapse/refractory AML; i.e. patients that currently have very limited therapeutic options and represent the highest unmet medical need. Disclosures Goubard: AB Science: Employment. Humbert:AB Science: Employment. Mansfield:AB Science: Employment, Patents & Royalties. Hermine:AB Science: Membership on an entity's Board of Directors or advisory committees. AB8939 Study Group:AB Science: Consultancy, Employment.

The Novel Fluoropyrimidine FdUMP[10] Is Highly Active Against Acute Myeloid Leukemia

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3302-3302
Author(s):  
Timothy Pardee ◽  
Evan Gomes ◽  
Jamie Jennings-Gee ◽  
David L. Caudell ◽  
William Gmeiner
Keyword(s):  
Acute Myeloid Leukemia ◽  
Cell Lines ◽  
Myeloid Leukemia ◽  
Single Agent ◽  
The Novel ◽  
Highly Active ◽  
Ic50 Values ◽  
Acute Myeloid

Abstract Abstract 3302 Acute Myeloid Leukemia (AML) is an aggressive myeloid malignancy that leads to marrow failure and death. This disease affects approximately 12,000 people per year in the United States, causing 9,000 deaths. Despite decades of research, therapy remains essentially unchanged and outcomes are poor. In patients over the age of 60 less then 10% of patients survive 5 years from diagnosis. There is a desperate need for the identification of new active agents with favorable toxicity profiles. The novel polymeric fluoropyrimidine (FP) FdUMP[10] is an oligodeoxynucleotide pro-drug of the thymidylate synthase (TS)-inhibitory FP metabolite 5-fluoro-2'-deoxyuridine-5`-O-monophosphate (FdUMP). The observation that this compound was highly active against several leukemia lines in the NCI 60 cell line screen prompted us to evaluate its activity in several preclinical models of AML. In vitro, FdUMP[10] exhibited remarkable activity against 3 human acute leukemia cell lines, HL60, Jurkat and THP-1, with IC50 values of 3.378 nM (95% CI 2.984 to 3.825), 5.438 nM (4.609 to 6.417) and 4.093 nM (3.413 to 4.907) respectively. We next tested its efficacy against a more genetically defined murine model of AML driven by expression of MLL-ENL. FdUMP[10] exhibited even greater activity against all murine lines tested. The IC50 values of FdUMP[10] against two MLL-ENL driven murine AML cell lines were 214 pM (95%CI 178.9 to 255.9) and 292.3 pM (251.8 to 339.4). The IC50 values observed for FdUMP[10] for all the murine lines tested were lower than both Ara-C (30-40 nM) and doxorubicin (2-4 nM). We then determined the cytotoxic mechanism for FdUMP[10] in vitro. Upon treatment with FdUMP[10] both the human and murine cell lines undergo extensive apoptosis as indicated by Annexin V and propidium iodide staining. Treated cells developed γH2AX foci, rapid and complete TS inhibition and display trapped Topoisomerase I (Topo I) cleavage complexes. FdUMP[10]-mediated induction of apoptosis was p53 independent as murine AML cells that had p53 knocked down by RNAi demonstrated resistance to both Ara-C and doxorubicin, but not to FdUMP[10]. We next tested the efficacy of FdUMP[10] in vivo. The MLL-ENL driven murine AML model results in blasts that can be transplanted into sublethally irradiated, immunocompetent, syngeneic recipients. The recipients develop a fatal and therapy-resistant AML. Lines were generated that expressed a luciferase reporter. Animals were imaged 6–7 days after injection of the leukemias to ensure engraftment and then began treatment with either the combination of Ara-C plus doxorubicin, single-agent FdUMP[10], or observation. Studies were performed using 2 doses of FdUMP[10] at 150 or 300 mg/kg injected on days 1 and 3 and compared to animals treated with 100 mg/kg Ara-C and 3mg/kg doxorubicin injected on days 1 through 5. Both treatments resulted in a statistically significant survival advantage over observation. A preliminary toxicology study compared FdUMP[10], 150 mg/kg daily, to 5-fluorouracil (5 FU), 150 mg/kg daily, or the combination of Ara-C at 100 mg/kg plus doxorubicin at 3 mg/kg daily. All groups were treated for 3, 4 or 5 days. On day 6 animals were sacrificed and organs harvested, sectioned, and stained. Slides were then reviewed by a veterinary pathologist. Tissues most affected were the small intestine, colon, and the bone marrow. The 5FU-treated animals had severe villous blunting and fusion with crypt necrosis in both large and small intestine. In contrast, FdUMP[10]-treated animals had only mild crypt epithelial apoptosis with mitoses. The 5 FU and Ara-C plus doxorubicin groups had a severe pan-cytopenia in the marrow compared to FdUMP[10] treated animals that showed only minimal to mild apoptosis. These data support the assertion that FdUMP[10] has lower toxicity then either Ara-C plus doxorubicin or identically dosed 5 FU. In summary FdUMP[10] exhibited remarkable activity against AML cells in vitro and in vivo. Additionally, FdUMP[10] had decreased toxicity compared to treatment with either single agent 5 FU or combination treatment with Ara-C plus doxorubicin. Disclosures: Gmeiner: Salzburg Therapeutics: Equity Ownership.

The Salicylamide Derivative, Niclosamide, Inhibits CREB Function in Acute Myeloid Leukemia Cells In Vitro and In Vivo

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1647-1647
Author(s):  
Hee-Don Chae ◽  
Nick Cox ◽  
Xiaohua Zhang ◽  
Jae Wook Lee ◽  
David Morgens ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Binding Protein ◽  
Luciferase Reporter ◽  
Therapeutic Window ◽  
Hl60 Cells ◽  
Acute Myeloid

Abstract CREB (cAMP Response Element Binding protein) is a transcription factor that is overexpressed in primary Acute Myeloid Leukemia (AML) cells and is associated with a decreased event-free survival and increased risk of relapse. We previously demonstrated that CREB overexpression increases leukemia cell growth and survival. Transgenic mice overexpressing CREB in myeloid cells develop a myeloproliferative neoplasm and myelodysplasia. CREB knockdown inhibits AML cell proliferation but not normal hematopoietic stem cell activity in vivo. To demonstrate the feasibility of targeting CREB for treatment for AML, we recently described a small molecule inhibitor of CREB, N-(4-cyanophenyl)-3-hydroxy-2-naphthamide (XX-650-23), which is a compound originally based on naphthol AS-E phosphate first identified as an inhibitor of CREB interaction with its coactivator, CBP (CREB Binding Protein). To identify a lead candidate with improved potency and physicochemical properties, we performed structure-activity relationships (SAR) studies for a series of salicylamides derived from naphthol AS-E phosphate. Development of this series led to the identification of the anthelmintic niclosamide as a potent agent that suppresses cell viability of five AML cell lines (IC50= 280 nM (HL60), 340 nM (KG1), 420 nM (MOLM13), 560 nM (MV411), 360 nM (U937), without a significant decrease in colony forming activity of normal bone marrow cells up to 10 μM (18- to 36-fold therapeutic window). Niclosamide binds CBP with a KD of 22.3 nM by Surface Plasmon Resonance (Biacore) analysis. To determine whether niclosamide specifically inhibits CREB-mediated gene expression in cells, luciferase reporter gene activity under the control of a promoter containing two CRE elements was measured after treatment of niclosamide for 6 hours. Niclosamide inhibited CREB-driven luciferase activity in HL60 cells with an IC50 of 1.09 μM. We also examined the efficacy of niclosamide in an AML patient-derived xenograft (PDX) mouse model. Niclosamide significantly inhibited the progression of AML in mice injected with primary AML cells. The percentage of circulating AML cells in the peripheral blood (%), vehicle vs. niclosamide treatment 5 weeks after engraftment were 28.75 ± 3.507 vs. 0.5363 ± 0.2744 (n=8, p< 0.001, mean ± SEM). In Kaplan Meier analysis, the median survival of PDX mice was 41 days vs. 51.5 days (p = 0.0015, log-rank test). To characterize the cellular effects of niclosamide, we analyzed the DNA profile, apoptosis, DNA-damage, cell cycle regulators, and other signaling molecules using flow cytometry. Niclosamide treatment increased DNA-damaged and apoptosis populations during the G1/S cell cycle phase, which also showed reduced phosphorylated CREB levels. To examine the functional requirement of CREB, we determined the effects of CREB knockdown in HL60 cells treated with niclosamide. CREB knockdown protected HL60 cells from niclosamide treatment-mediated cytotoxic effects (IC50=670 nM for CREB knockdown vs. 200 nM for vector control cells). Furthermore, combination treatment of niclosamide with XX-650-23 in HL60 cells showed an additive antiproliferative effect, suggesting that niclosamide and XX-650-23 regulate the same targets or pathways to inhibit viability of AML cells. To further identify genes that confer resistance or sensitivity to niclosamide, we performed a functional shRNA screen using subsets of whole genomic shRNA libraries (apoptosis, motility, other cancer; 35154 elements). We identified 53 genes, including tumor necrosis factor receptor superfamily members, which when knocked downed conferred resistance to niclosamide at a 10% false discovery rate. Taken together, our results demonstrate that niclosamide is a potential drug to treat AML by inducing DNA-damage, apoptosis and cell cycle arrest through the inhibition of CREB-dependent pathways in AML cells. Disclosures No relevant conflicts of interest to declare.

Low efficacy of methotrexate in childhood acute myeloid leukemia (AML): Single-agent therapeutic window study in relapsed AML

2006 ◽  
Vol 47 (5) ◽  
pp. 539-542 ◽  
Author(s):  
G.J.L. Kaspers ◽  
D. Reinhardt ◽  
G. Fleischhack ◽  
H. Armendariz ◽  
B. Stark ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Single Agent ◽  
Therapeutic Window ◽  
Childhood Acute Myeloid Leukemia ◽  
Acute Myeloid

scholarly journals Comparing cure rates for gemtuzumab ozogamicin plus standard chemotherapy vs standard chemotherapy alone in acute myeloid leukemia patients

2021 ◽  
Author(s):  
Bogdan Muresan ◽  
Carla Mamolo ◽  
Joseph C Cappelleri ◽  
Ruth Mokgokong ◽  
Athina Palaka ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Survival Rates ◽  
Gemtuzumab Ozogamicin ◽  
Standard Chemotherapy ◽  
Term Survival ◽  
Long Term Survival ◽  
Cure Rates ◽  
Acute Myeloid

Aim: Assess the suitability of standard parametric, piecewise and mixture cure models (MCMs) for modeling long-term survival of acute myeloid leukemia patients achieving remission following treatment with gemtuzumab ozogamicin (GO) + standard chemotherapy (SC) or SC alone. MCMs can model survival data comprising of statistically cured (patients in long-term remission) and uncured patients. Materials & methods: Models were fit to patient-level data corresponding to individual treatment arms. Results: Visual inspection showed that MCMs fit the clinical data best. Survival modeling with MCMs showed that treatment with GO + SC versus SC alone results in higher statistical cure rates for event-free survival (rates: 26–35% vs 21–23%) and overall survival (rates: 48–52% vs 38–44%). Conclusion: MCMs are well suited to modeling long-term survival in acute myeloid leukemia patients. Clinical trial registration: NCT00927498 ( ClinicalTrials.gov )

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