The mTOR Inhibitor RAD001 (Everolimus) Improves Survival in Preclinical Models of Primary Human ALL.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 856-856 ◽  
Author(s):  
Roman Crazzolara ◽  
Adam Cisterne ◽  
Marilyn Thien ◽  
John Hewson ◽  
Kenneth Francis Bradstock ◽  
...  
Keyword(s):  
Lymphoblastic Leukemia ◽  
Critical Role ◽  
Single Agent ◽  
Mammalian Target Of Rapamycin ◽  
Constitutive Expression ◽  
Leukemic Cell ◽  
Mtor Inhibitors ◽  
Leukemic Cells ◽  
Control Group

Abstract The Akt/mammalian target of rapamycin (mTOR) signaling pathway is a potential target in acute lymphoblastic leukemia (ALL) due to its constitutive expression and critical role in regulating leukemic cell growth and survival. In this study, we investigated whether RAD001 (Everolimus, Novartis), is effective as a therapeutic agent in a murine model of human ALL. Leukemic cells from 5 separate patient samples were injected into sub-lethally irradiated NOD/SCID mice and treatment was started after leukemia was clearly detectable in the blood (>5% peripheral blasts) and continued for 4 weeks. In 2 of 3 cases examined, animals treated with RAD001 as a single agent (5mg/kg, 3 times weekly) showed 2 to12-fold reduction in the number of circulating blasts and 2.5 to 30-fold decrease in splenomegaly after only 7 days of treatment (p<0.01). In 1 case, blasts completely disappeared by 14 days of treatment accompanied by recovery of normal hematopoiesis. In contrast vehicle treated mice showed progressive leukemia. In all 5 cases examined, decreased leukemic burden was associated with increased survival, with a median survival of 52 days in the RAD001 treated mice compared to 24 days in the control group (p<0.02 for all samples). Combination treatment with RAD001 and Vincristine (0.15–0.25 mg/kg, weekly) was more effective than either agent alone in reducing leukemic cell count and prolonging survival (p<0.02 compared to Vincristine alone). In one case, all mice treated with either RAD001 alone or RAD001 plus Vincristine survived for greater than 10 weeks following the completion of treatment and only one animal (RAD001 treated) showed signs of disease on elective sacrifice. Cell cycle analysis of cells recovered from the spleens of RAD001 treated animals revealed an arrest in the G0/G1 phase. Furthermore, electron microscopy demonstrated the predominant appearance of autophagy as well as limited apoptosis in cells within the sternums of treated animals. In conclusion, we have demonstrated the efficacy of RAD001 alone or with a subtherapeutic dose of Vincristine in an in vivo leukemia model. These preclinical results support further clinical development of mTOR inhibitors for the treatment of ALL patients. RAD001 may provide significant therapeutic benefit when used alone, or in combination with standard chemotherapy agents such as Vincristine.

Pharmacokinetic and Pharmacodynamic Effects of PEG-Asparaginase in Newly Diagnosed Childhood Acute Lymphoblastic Leukemia: Results from a Single Agent Window Study.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 860-860
Author(s):  
Inge M. Appel ◽  
Karin M. Kazemier ◽  
Anjo J.P. Veerman ◽  
Elisabeth van Wering ◽  
Monique L. Den Boer ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Clinical Response ◽  
Lymphoblastic Leukemia ◽  
Single Agent ◽  
Hazard Ratio ◽  
Leukemic Cells ◽  
Newly Diagnosed ◽  
Pharmacodynamic Effects

Abstract L-Asparaginase is an effective drug for treatment of children with acute lymphoblastic leukemia. The effectiveness is generally thought to result from a rapid depletion of asparagine in serum and cells. Several studies have shown that in vitro resistance to this drug is an independent prognostic factor in ALL. We investigated the clinical response of one in vivo dose of 1000 IU/m2 PEG-Asparaginase and its pharmacokinetic and pharmacodynamic effects in children with newly diagnosed ALL before the start of combination chemotherapy. 57 children (36M / 21F) were enrolled in the study: 2 pro B-ALL, 38 common/ pre B-ALL and 17 T-ALL. Genotyping of precursor B-ALL revealed 11 hyperdiploid, 8 TELAML1 positive, 2 BCRABL positive, no MLL rearrangement, 8 normal, 11 others. The clinical response to PEG-Asparaginase on day 0 (5 days after the PEG-Asparaginase infusion) was defined as good when the number of leukemic cells of peripheral blood was < 1 × 109/L, as intermediate when leukemic cells were 1-10 × 109/L, and as poor when leukemic cells were > 10 × 109/L. The in vivo window response was significantly related to immunophenotype and genotype: 26/38 common / pre B-ALL cases, especially those with hyperdiploidy and TELAML1 rearrangement, demonstrated a good clinical response compared to 8/17 T-ALL (p=0.01). Both BCRABL positive ALL cases showed a poor response (p=0.04). A poor in vivo clinical window response was related to in vitro resistance to L-Asparaginase (p=0.02) and both in vitro as well as in vivo response were prognostic factors for long-term event-free survival (Hazard ratio 6.4; p=0.004, and Hazard ratio 3.7; p=0.01, respectively). The L-Asparaginase activity in the serum was >100 IU/L for at least 15 days. The asparagine levels remained below the detection limit of 0.2 mM for at least 26 days with a concomitant rise in serum aspartate and glutamate. These findings confirm that PEG-Asparaginase will yield its pharmacodynamic effects for 2-4 weeks. After administration of one in vivo dose of 1000 IU/m2 PEG-Asparaginase no changes in apoptotic parameters or changes in intracellular levels of twenty amino acids in leukemic cells could be measured, in contradiction to the changes found after in vitro exposure. This may be explained by the rapid removal of apoptotic cells from the circulation in vivo. Otherwise it is possible that in vivo mesenchymal cells from the bone marrow supply leukemic blasts with asparagine in response to treatment with L-Asparaginase. Conclusion: The clinical response to one dose of 1000 IU/m2 PEG-Asparaginase intravenously is related to phenotype and genotype and predicts outcome. These results suggest that children with ALL with a poor clinical response to PEG-Asparaginase might benefit from a more intensive antileukemic therapy.

scholarly journals CD7+, CD4-, CD8- acute leukemia: a syndrome of malignant pluripotent lymphohematopoietic cells

Blood ◽  
1989 ◽  
Vol 73 (2) ◽  
pp. 381-390
Author(s):  
J Kurtzberg ◽  
TA Waldmann ◽  
MP Davey ◽  
SH Bigner ◽  
JO Moore ◽  
...  
Keyword(s):  
Lymphoblastic Leukemia ◽  
Leukemic Cell ◽  
Leukemic Cells ◽  
Cell Phenotype ◽  
Therapeutic Approaches ◽  
Myeloid Leukemias ◽  
Cell Gene ◽  
In Vitro Data

Following our initial observation of in vivo conversion of CD7+, CD4-, CD8- acute lymphoblastic leukemia (ALL) cells from lymphoid to myeloid lineages (Proc Natl Acad Sci (USA) 81:253, 1984) we have studied eight additional cases of ALL with this leukemic cell phenotype. The CD7+, CD4-, CD8- phenotype was associated with a distinct clinical entity with those affected predominantly male (either less than 35 years or greater than 65 years of age), with frequent mediastinal and/or thymic masses, skin and CNS disease, high peripheral WBC counts, and bone marrow blasts that were morphologically L1 or not ascribable to a specific lineage. These patients did not respond to conventional chemotherapeutic regimens for either acute lymphoid or myeloid leukemias. No common karyotype or T-cell gene rearrangement pattern could be defined. Importantly, seven of eight patient's leukemic cells studied were capable of multilineage (myeloid, erythroid, monocytoid, megakaryocytoid, and lymphoid) differentiation in vitro. Data is presented suggesting that CD7+, CD4-, CD8- leukemias, in many instances, are leukemias of immature hematopoietic cells. The development of novel therapeutic approaches to this form of leukemia will be necessary to alter its poor prognosis.

CXCR4 Antagonists Mobilize Acute Lymphoblastic Leukemia Cells into the Peripheral Blood and Inhibit Engraftment in Mice.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4592-4592
Author(s):  
Julius Juarez ◽  
John Hewson ◽  
Adam Cisterne ◽  
Rana Baraz ◽  
Kenneth F. Bradstock ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
B Cell ◽  
Cell Count ◽  
Peripheral Blood ◽  
Lymphoblastic Leukemia ◽  
Leukemic Cell ◽  
Leukemic Cells ◽  
Cxcr4 Antagonists

Abstract The role of CXCL12 in the growth of B cell progenitor acute lymphoblastic leukemia (ALL) and the homing of these cells to the bone marrow has been well established. However the effect of modulating CXCL12/CXCR4 interactions on the growth of ALL cells in vivo has not been examined. In this study we used specific peptide and small molecule antagonists of CXCR4 to examine the importance of CXCL12/CXCR4 interactions in the development of leukemia in an in-vivo murine model of ALL. CXCR4 antagonists induced mobilization of human and murine B cell progenitor ALL cells into the peripheral blood, with a 3.8±1.9 and 6.5±3.3 fold increase in leukemic cells/ml one hour after administration of the antagonist respectively, similar to that observed for normal progenitors. Daily administration of AMD3100 commencing the day following the injection of cells and continuing for 21 days resulted in a mean reduction in peripheral blood white cell count of 50±12% and the leukemic cell count of 63±4%. There was also a significant reduction in both the total cells in the spleen of 58±1% and the leukemic cell number in this organ of 75±11%. A significant reduction in leukemic cell numbers in the bone marrow was observed in one (44% reduction) case. There was reduced infiltration of other organs including kidney, liver and skeletal muscle. This study demonstrates that disrupting the CXCL12/CXCR4 axis in B cell progenitor ALL reduces the tumor burden. Whether this is due to direct inhibitory effects on proliferation and survival, or results from disruption of the leukemic cell interactions within the bone marrow remains to be determined.

Preclinical Evaluation of Tysabri as a Novel Adjuvant Therapy against Drug Resistant B-ALL.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3089-3089 ◽  
Author(s):  
Yao-Te Hsieh ◽  
Enzi Jiang ◽  
Carlton Scharman ◽  
Ella Waters ◽  
Eugene Park ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Adjuvant Therapy ◽  
Conflicts Of Interest ◽  
Lymphoblastic Leukemia ◽  
Single Agent ◽  
Scid Mice ◽  
Prolonged Survival ◽  
Control Group ◽  
Drug Resistant

Abstract Abstract 3089 Poster Board III-26 Novel treatment strategies for pediatric acute lymphoblastic leukemia (ALL) have turned a rapidly deadly diagnosis into a highly treatable entity, but we are still failing 25% of our pediatric ALL patients who die of recurrent ALL. Definitive studies have demonstrated that adhesion of leukemia and lymphoma cells to extracellular matrices or stromal cells protects them against the toxicity of cytoreductive chemotherapy drugs. In this context, a specific role for CD49d, a dominant adhesion molecule for normal lymphocytes, was demonstrated for acute myeloid leukemia (AML) and other malignant hematopoietic cells. The finding that CD49d blockade sensitizes AML cells to chemotoxicity may be of therapeutic potential, as is suggested by recent findings for AML cells engrafted in NOD/SCID mice. CD49d is and is similarly expressed on acute lymphoblastic leukemia (ALL) cells, but our knowledge about CD49d adhesion-mediated chemoprotection of B-ALL is limited. We hypothesized whether similar to primary AML blasts, xenografted ALL cells resistant to chemotherapy can be sensitized to chemotherapy by disrupting their CD49d-mediated adhesive interaction with stroma. To test our hypothesis we used as a CD49d inhibitor the humanized anti-human CD49d antibody natalizumab, or Tysabri®, which is in clinical use for the treatment of relapsing or refractory Multiple Sclerosis. To determine the potential of Tysabri as a single agent to decrease leukemia progression, we engrafted 5-7 weeks old NOD/SCID mice with primary drug resistant B-ALL labeled with lentiviral luciferase to allow monitoring of leukemia using noninvasive bioluminescent imaging. Tysabri administered upon detection of engraftment on Day15 post-injection of leukemia in the dose of either 1 mg (n=3) or 6 mg (n=3) led to remarkably slower leukemia progression regardless of the dose compared to the control group treated with saline only (n=2). Additional administration of Tysabri on day 29 and day 37 did not result in further containment of leukemogenesis but still showed a marked reduction in progression compared to the saline treated control group. In addition, we determined in vivo that a weekly administration of Tysabri in the dose of 5mg/kg/d resulted in prolonged survival compared to the treated control (p<0.05). Next, we assessed the effect of adjuvant anti-CD49d antibody-mediated dislodgement of ALL cells of drug resistant patients in combination with chemotherapy. The group treated for 4 weeks with chemotherapy including Vincristine, Dexamethasone and L-Asparaginase (VDL) in combination with Tysabri (5mg/kg/d) admistered once weekly showed decreased progression of leukemia and significantly prolonged survival (p<0.05) compared to the VDL only treated control group. No toxicity of Tysabri treatment was observed. Taken together, our data indicates the potential of Tysabri as a novel adjuvant therapy for treatment of drug resistant B-ALL. Given the availability of clinical-grade CD49d blocking antibody, clinical studies can follow immediately, should our hypothesis be confirmed in further in vitro an in vivo studies. Disclosures No relevant conflicts of interest to declare.

scholarly journals mTOR inhibitors are synergistic with methotrexate: an effective combination to treat acute lymphoblastic leukemia

Blood ◽  
2008 ◽  
Vol 112 (5) ◽  
pp. 2020-2023 ◽  
Author(s):  
David T. Teachey ◽  
Cecilia Sheen ◽  
Junior Hall ◽  
Theresa Ryan ◽  
Valerie I. Brown ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Cyclin D1 ◽  
Lymphoblastic Leukemia ◽  
Single Agent ◽  
Mtor Inhibitors ◽  
Mechanistic Explanation ◽  
Effective Combination ◽  
Turn Over

Abstract We have previously demonstrated that mTOR inhibitors (MTIs) are active in preclinical models of acute lymphoblastic leukemia (ALL). MTIs may increase degradation of cyclin D1, a protein involved in dihydrofolate reductase (DHFR) synthesis. Because resistance to methotrexate may correlate with high DHFR expression, we hypothesized MTIs may increase sensitivity of ALL to methotrexate through decreasing DHFR by increasing turn-over of cyclin D1. We tested this hypothesis using multiple ALL cell lines and nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice xenografted with human ALL. We found MTIs and methotrexate were synergistic in combination in vitro and in vivo. Mice treated with both drugs went into a complete and durable remission whereas single agent treatment caused an initial partial response that ultimately progressed. ALL cells treated with MTIs had markedly decreased expression of DHFR and cyclin D1, providing a novel mechanistic explanation for a combined effect. We found methotrexate and MTIs are an effective and potentially synergistic combination in ALL.

scholarly journals Mine the Stability of the G2/M Checkpoint to Break Down Acute Lymphoblastic Leukemia Defenses Against Antineoplastic Drugs

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2808-2808
Author(s):  
Andrea Ghelli Luserna di Rorà ◽  
Ilaria Iacobucci ◽  
Neil Beeharry ◽  
Maria Vittoria Falzacappa ◽  
Chiara Ronchini ◽  
...  
Keyword(s):  
Cell Viability ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Single Agent ◽  
Leukemic Cell ◽  
Leukemic Cells ◽  
Antineoplastic Drugs ◽  
Primary Cells ◽  
Dna Damages ◽  
Leukemic Cell Lines

Abstract Although impressive developments have been made in the treatment of Acute Lymphoblastic Leukemia (ALL) patients, the overall survival is still very poor. With the exception of novel therapeutic strategies based on monoclonal antibodies (Bi-specific T-cell engagers, BiTEs) or immunogenic cells (CART cells), the therapeutic approaches for adult ALL patients are still base on non-selective chemotherapy or on tyrosine kinase inhibitors (TKIs) for the patients harboring the BCR-ABL1 fusion transcript. In addition a large percentage of initial successfully treated patients frequently develop relapses. Thus there is a need to improve the efficacy of conventional therapies, in particular those related to TKIs and to DNA damaging agents, in order to reduce the off-target toxicity and avoid relapses. In the present study we evaluated the in vitro, ex vivo and in vivo efficacy of MK-1775, a specific Wee1 inhibitor, in single agent and in combination with different therapeutic agents normally used for the treatment of B-/T-ALL. We firstly started by evaluated the efficacy of the compound in single agent on a panel of human B and T ALL cell lines (n=8) and on primary cells isolated from the bone marrow of adult B-ALL patients (n=8). The inhibition of Wee1 deeply reduced the cell viability and the proliferation rate, induced the apoptosis and increased the DNA damages of both leukemic cell lines and primary cells. Further cell-cycle analysis showed that in leukemic cell lines the treatment increased the number of cell in late S and G2/M phase. Light microscopy analyses, looking for nuclei morphology, confirmed that MK-1775 increased the number of mitotic cells but it interfered with normal mitotic division (induction of aberrant mitosis as showed by the increment of DNA bridges and micro-nuclei). The effects of the compound on the cell cycle profile and on the G2/M checkpoint were confirmed also in immunoblotting analyses, by the increment of phospho-HH3(ser10) and of Myt1 (mitotic isoform), and by gene expression analysis looking to specific genes involved in the G2/M checkpoints (PrimePcr DNA damage assay, Biorad). In particular genes like GADD45A and CCNB1/CCNB2 were significantly up-regulated between treated and untreated samples. Finally using a T-ALL mouse model we evaluated the effect of MK-1775 in single agent. Although no significative differences were seen between treated and un-treated samples, due to a very aggressive phenotype of the disease (all animal died after only 18 days from the engraftment), molecular analyses confirmed that the treatment induced DNA damages (increase of H2A.X and p-Chk1 ser317) and inhibited Wee1 functionality (reduction of pCDC2) on leukemic blasts isolated from both spleens and bone marrows. To evaluate if the inhibition of the G2/M checkpoint could sensitize leukemic cells to the toxicity of antineoplastic drugs, Philadelphia-negative ALL cell lines and primary leukemic cells (n=9) where treated with increasing concentration of MK-1775 and increasing concentration of the nucleotide analogue, clofarabine. Statistical analyses (Combination index value) confirmed the synergy of the combination in the reduction of the cell viability, in the inhibition of the proliferation and in the induction of the apoptosis. Similar results were seen on Philadelphia-positive ALL cell lines and primary cells (n=3) combining the MK-1775 with the TKI, bosutinib. The simultaneously inhibition of the Wee1 and the BCR-ABL downstream pathway resulted in a synergic inhibition of the cell viability, reduction of the proliferation and induction of apoptosis. In our opinion the pre-clinical results of this study are the basis for a future clinical evaluation of MK-1775 for the treatment of ALL patients. Acknowledgments: ELN, AIL, AIRC, progetto Regione-Università 2010-12 (L. Bolondi), Fondazione del Monte di Bologna e Ravenna, FP7 NGS-PTL project. Disclosures Martinelli: Novartis: Speakers Bureau; BMS: Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; MSD: Consultancy; Pfizer: Consultancy, Speakers Bureau; Ariad: Consultancy, Speakers Bureau; Genentech: Consultancy; Celgene: Consultancy, Speakers Bureau.

scholarly journals Efficacy of Focal Adhesion Kinase Inhibition in Combination with Dasatinib in BCR-ABL1 Acute Lymphoblastic Leukemia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3766-3766 ◽  
Author(s):  
Michelle L. Churchman ◽  
Luke Jones ◽  
Kathryn Evans ◽  
Jennifer Richmond ◽  
Irina M Shapiro ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
Lymphoblastic Leukemia ◽  
Single Agent ◽  
Leukemic Cells ◽  
Employment Equity ◽  
Self Renewal ◽  
Equity Ownership

Abstract Introduction: BCR-ABL1+ B-progenitor acute lymphoblastic leukemia (Ph+ B-ALL) is a highly aggressive disease that is often refractory to currently available therapies. Our previous genomic profiling studies have identified loss-of-function or dominant negative mutations in IKZF1, encoding the lymphoid transcription factor Ikaros, in over 80% of Ph+ ALL. In addition, deletion of CDKN2A, which encodes the INK4A and ARF tumor suppressors, is observed in approximately half of all cases (Mullighan et al., 2008). Alterations of IKZF1 are associated with poor outcome despite the use of tyrosine kinase inhibitors (TKIs). Ikzf1 alterations, including Ikaros isoform 6 (IK6), result in the acquisition of stem cell-like features, enhanced self-renewal, expression of adhesion molecules, and transcriptional upregulation of focal adhesion kinase (FAK), resulting in increased adhesion in vitro and in vivo, and decreased sensitivity to TKIs (Churchman, Cancer Cell, in press). VS-4718 is a potent, selective, and orally bioavailable FAK inhibitor currently under evaluation in a phase 1 clinical trial in subjects with various solid tumors, however in vivo efficacy in hematological malignancies had not been evaluated. Targeting FAK with VS-4718 is an attractive approach to abrogate the adhesive phenotype of IKZF1-altered leukemic cells potentially enhancing the effects of dasatinib in the treatment of high-risk BCR-ABL1 B-ALL. Methods: We examined the efficacy and mechanisms of FAK inhibition using VS-4718 as a single agent and in combination with dasatinib in vitro and in vivo in a range of xenograft and genetically engineered mouse models of BCR-ABL1 ALL. Each model had concomitant deletion of Arf which is observed in approximately 50% of human cases. Results: A pre-clinical in vivo trial of dasatinib and VS-4718 combination therapy in a murine C57Bl/6 Arf-/- BCR-ABL1 pre-B cell model resulted in a marked increase in survival in both IK6-expressing and non-IK6 cohorts of mice, and one complete long-term remission in the IK6-expressing group. Further, we showed increased efficacy of VS-4718 and dasatinib, compared to either agent alone, against two highly aggressive human Ph+ IK6-expressing B-ALL xenografts in vivo, with decreased infiltration of leukemic cells in bone marrow and spleens demonstrating a synergistic effect of the VS-4718/dasatinib combination. In vitro cell viability was reduced with induction of apoptosis at increasing concentrations of VS-4718 as a single agent, and further potentiated the effects of dasatinib in cytotoxicity assays using human xenografted and murine leukemic cells. VS-4718 profoundly diminished the ability of BCR-ABL1-expressing cells to form cell-matrix adhesions in vitro, as evident by the reduced adherence to fibronectin monolayers and bone marrow stromal cells. VS-4718 almost completely abolished the colony-forming potential of BCR-ABL1-expressing murine pre-B cells with and without Ikzf1 alterations at drug concentrations that do not affect cell viability suggestive of a reduction in self-renewal. Calvarial imaging of mice transplanted with Ikzf1-altered BCR-ABL1 leukemic cells and treated with VS-4718 alone in vivo revealed a discernible reduction in adhesion in the intact bone marrow niche of Prrx1-Cre; LSL-tdTomato recipient mice. VS-4718 treated leukemic cells localized to Prrx1-expressing perivascular endothelial cells and exhibited round morphology in contrast to the typical spindle-like appearance of Ikzf1-altered pre-B cells adhering to the bone marrow stroma, suggesting that VS-4718 treatment abolished the aberrant leukemic cell-stromal adhesion induced by Ikaros alterations in vivo. Conclusions: Direct inhibition of FAK with VS-4718 attenuates the adhesive, stem-like properties of IKZF1-altered BCR-ABL1 leukemic cells that contribute to the poor prognosis of patients treated with currently available therapies. Targeted FAK inhibition is thus a promising avenue for improving the response of BCR-ABL1 ALL to dasatinib, particularly in refractory cases harboring IKZF1 alterations. These data support the clinical development of VS-4718 in combination with dasatinib in Ph+ B-ALL. Disclosures Shapiro: Verastem: Employment, Equity Ownership. Pachter:Verastem: Employment, Equity Ownership. Weaver:Verastem: Employment, Equity Ownership. Mullighan:Amgen: Honoraria, Speakers Bureau; Cancer Science Institute: Membership on an entity's Board of Directors or advisory committees; Loxo Oncology: Research Funding; Incyte: Consultancy, Honoraria. Off Label Use: The FAK inhibitor VS-4718 for the treatment of BCR-ABL1 acute lymphoblastic leukemia in preclinical models.

scholarly journals CD7+, CD4-, CD8- acute leukemia: a syndrome of malignant pluripotent lymphohematopoietic cells

Blood ◽  
1989 ◽  
Vol 73 (2) ◽  
pp. 381-390 ◽  
Author(s):  
J Kurtzberg ◽  
TA Waldmann ◽  
MP Davey ◽  
SH Bigner ◽  
JO Moore ◽  
...  
Keyword(s):  
Lymphoblastic Leukemia ◽  
Leukemic Cell ◽  
Leukemic Cells ◽  
Cell Phenotype ◽  
Therapeutic Approaches ◽  
Myeloid Leukemias ◽  
Cell Gene ◽  
In Vitro Data

Abstract Following our initial observation of in vivo conversion of CD7+, CD4-, CD8- acute lymphoblastic leukemia (ALL) cells from lymphoid to myeloid lineages (Proc Natl Acad Sci (USA) 81:253, 1984) we have studied eight additional cases of ALL with this leukemic cell phenotype. The CD7+, CD4-, CD8- phenotype was associated with a distinct clinical entity with those affected predominantly male (either less than 35 years or greater than 65 years of age), with frequent mediastinal and/or thymic masses, skin and CNS disease, high peripheral WBC counts, and bone marrow blasts that were morphologically L1 or not ascribable to a specific lineage. These patients did not respond to conventional chemotherapeutic regimens for either acute lymphoid or myeloid leukemias. No common karyotype or T-cell gene rearrangement pattern could be defined. Importantly, seven of eight patient's leukemic cells studied were capable of multilineage (myeloid, erythroid, monocytoid, megakaryocytoid, and lymphoid) differentiation in vitro. Data is presented suggesting that CD7+, CD4-, CD8- leukemias, in many instances, are leukemias of immature hematopoietic cells. The development of novel therapeutic approaches to this form of leukemia will be necessary to alter its poor prognosis.

scholarly journals Pre-Clinical Efficacy of the Novel Kinase Inhibitor Nintedanib on PAX5 Fusion Genes in Pediatric Ph-like B-Cell Precursor Acute Lymphoblastic Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 745-745
Author(s):  
Grazia Fazio ◽  
Silvia Bresolin ◽  
Claudia Saitta ◽  
Daniela Silvestri ◽  
Elena Vendramini ◽  
...  
Keyword(s):  
B Cell ◽  
Kinase Inhibitor ◽  
Fusion Gene ◽  
Ex Vivo ◽  
Lymphoblastic Leukemia ◽  
Single Agent ◽  
Leukemic Cells ◽  
Fusion Genes ◽  
Significant Efficacy

Despite the current risk-based stratification protocol, 15% of pediatric patients with B-Cell Precursor Acute Lymphoblastic Leukemia (BCP-ALL) still experience relapse. In the large subset of 'B-other' patients (negative for common fusion transcripts, non-high hyperdiploid and non-Down Syndrome), 'Ph-like' is a high risk subgroup with high incidence of relapses, which represents 30% of B-others or 10-15% of BCP-ALL patients. The PAX5 gene, encoding for a B-cell related transcription factor, is frequently involved in several translocations in Ph-like patients, determining the formation of fusion genes encoding for aberrant proteins. Our previous studies showed that PAX5 fusions sustain survival of leukemic cells by Lymphocyte kinase (LCK) hyperactivation, which can be targeted by the kinase inhibitor Nintedanib/BIBF1120. This study aims (i) to unravel the functional features of PAX5 fusion genes, elucidating the involved signaling pathways; (ii) to develop new pre-clinical strategies to target PAX5 fusion genes, testing the efficacy of the LCK inhibitor BIBF1120. We selected a cohort of 138 B-other cases among 400 childhood BCP-ALL cases enrolled in Italy in AIEOP-BFM ALL2000/R2006 protocols; by gene expression analysis (HG-U133Plus2.0 Affymetrix array), 59/138 presented as Ph-like, and by NGS, a driver fusion gene was identified in 34/59 (58%). Beside known genetic lesions, such as P2RY8/CLRF2 (N=9), EBF1 fusions (N=3), TCF3/HLF (N=1), IKZF1-fusion (N=1) and BCL9/MEF2D (N=1), and single cases with novel fusions, seven cases were carrying a PAX5 fusion gene, representing the most frequent rearrangement. Ex-vivo inhibition with BIBF1120 was setup on primary cells from 5 PAX5-fusion BCP-ALL samples, demonstrating significant efficacy in inducing leukemic cell apoptosis, both as single agent and in combination with standard chemotherapeutic agents (Annexin V viability assay of leukemic cells in co-culture on human bone marrow stroma). Strikingly, in 3/5 cases dexamethasone and BIBF1120 had a synergistic effect and were further tested in in vivo assays. A daily treatment was performed at bulk disease detection (BM aspiration, mean engraftment 20% CD10/CD19+) in patient-derived xenotransplanted NSG mice from 2 different PAX5 fusion cases. At the endpoint (after two weeks), in the PAX5/AUTS2 PDX mice we detected a mild effect in the BM by BIBF1120 alone (disease reduction 24%, p=0.057), further enhanced in combination with dexamethasone (-49%, p=0.005, with a mean engraftment in vehicle mice of 82.6%). In the spleen, the efficacy was highly significant both for BIBF1120 (-52%, p=0.025) and the combination (-91%, p=0.015, mean engraftment vehicle 69.5%). A similar statistical significant effect was observed also in peripheral blood, whilst, BIBF1120 alone showed a specific significant efficacy in CNS meninges. Analogous results have been observed in PDX from the PAX5/DACH2 PDX mice; BM leukemia decreased 47% using BIBF1120 alone (p=0.004), further diminished by the combination (-65%, p=0.0004, with a mean engraftment in vehicle mice of 65%). In the spleen, the efficacy was highly significant both with BIBF1120 (-45.6%, p=0.04) and for the combination (-96.3%, p=0.0008, mean engraftment vehicle 72.4%). Strikingly, BIBF1120 treatment alone showed analogous efficacy in PB and CNS, with leukemia decrease as low as -45% (p=0.04) and -76% (p=0.007), respectively, and the combination nearly achieved remission in PB (-94%, p=0.0001) and it was significant in CNS (-81.2%, p=0.03). Dexamethasone alone was not effective in the BM and spleen, whereas it decreased the leukemia bulk both in PB (-65%, p=0.0004) and CNS (-52.8%, p=0.03). Overall, BIBF1120 treatment was more effective than dexamethasone. Interestingly, phosphoflow analysis showed a marked inhibition by BIBF1120 of pAkt-Thr308 and its downstream effectors, such as pS6 and 4pEBP1, in ex vivo BM and spleen cells. In conclusions, PAX5 fusion genes are highly recurrent among Ph-like patients and can potentially be targeted by Nintendanib/BIBF1120, that showed a significant effect ex vivo and in vivo, even as a single agent. Disclosures No relevant conflicts of interest to declare.

Effective Targeting of Leukemic Cells in Children with B-Precursor Acute Lymphoblastic Leukemia Treated with Anti-CD22 (Epratuzumab). A Children’s Oncology Group (COG) Study.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2585-2585 ◽  
Author(s):  
Michael J. Borowitz ◽  
William L. Carroll ◽  
Peter C. Adamson ◽  
Mitchell S. Cairo ◽  
David M. Goldenberg ◽  
...  
Keyword(s):  
Induction Chemotherapy ◽  
Lymphoblastic Leukemia ◽  
Single Agent ◽  
Poor Response ◽  
Antigen Expression ◽  
Response To Therapy ◽  
Leukemic Cells ◽  
Color Flow

Abstract Identifying new approaches to treating relapsed ALL is a top priority because these patients fare poorly with current retrieval strategies. COG protocol ADVL04P2 is a phase I/II feasibility pilot study for children with relapsed B-precursor ALL that uses epratuzumab, a humanized anti-CD22 monoclonal antibody, in combination with conventional re-induction chemotherapy. Children whose blasts are CD22 positive first receive 4 doses of 360 mg/m2 epratuzumab as a single agent on days minus(−)14, −10, −6 and −2. Subsequently, they receive epratuzumab weekly in combination with standard re-induction chemotherapy starting on day 0. We assessed the effectiveness of epratuzumab targeting by by assaying CD22 expression on residual leukemic blasts. Peripheral blood was obtained from 15 patients 24 hours after administration of the first dose (day −13), and again at day −6 and day 0 and stained with the combination of CD10/CD22/CD45/CD19 in four color flow cytometry to permit assessment of CD22 on analytically isolated leukemic blasts. We determined quantitative expression of CD22 with a calibration kit (Quantibrite, BDBiosciences, San Jose, CA) using two PE-conjugated anti CD22 antibodies directed against different epitopes of the CD22 molecule: clone RFB4 (Caltag, Burlingame CA), directed against the same epitope as epratuzumab, and clone SHCL-1 (BDBiosciences), directed against a non-cross-reacting epitope of CD22. RFB4 binding was decreased by more than 99% within 24 hours after administration of the first dose in all patients, indicating rapid targeting of epratuzumab to leukemic cells. In all but 4 patients, levels remained low at all subsequent time points; in 2 patients expression was restored to about 15% of baseline levels by day 0, and 2 additional patients had very small (1–2%) subsets of blasts with significant expression, one at day −6 and one at day 0. In contrast to RFB4, SHCL-1 identified residual CD22 antigen expression, but SHCL-1 binding was decreased by an average of 70–75% in 14 of 15 patients at all three post-epratuzumab timepoints. The one patient with no change in SHCL-1 binding was a patient with MLL-rearranged ALL with very low levels of CD22 expression at diagnosis, and poor response to therapy. Because binding of epratuzumab to CD22 has been shown to result in antigen internalization in vitro, we interpret our findings as demonstrating in vivo internalization of CD22 with epratuzumab binding, though we cannot exclude either shedding of antigen or conformational change to block SHCL-1 sites. We conclude that epratuzumab rapidly targets CD22 on ALL blasts in vivo, though some blasts in some patients may escape over time. Targeting is associated with a physical change in CD22 antigen expression in most patients, most likely through internalization.

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