scholarly journals Moving on up: Second-Line Agents as Initial Treatment for Newly-Diagnosed Patients with Chronic Phase CML

2011 ◽  
Vol 5 ◽  
pp. CMO.S6416 ◽  
Author(s):  
Marie P. Shieh ◽  
Masato Mitsuhashi ◽  
Michael Lilly

The treatment of chronic myelogenous leukemia (CML) was revolutionized by the development of imatinib mesylate, a small molecule inhibitor of several protein tyrosine kinases, including the ABL1 protein tyrosine kinase. The current second generation of FDA-approved ABL tyrosine kinase inhibitors, dasatinib and nilotinib, are more potent inhibitors of BCR-ABL1 kinase in vitro. Originally approved for the treatment of patients who were refractory to or intolerant of imatinib, dasatinib and nilotinib are now also FDA approved in the first-line setting. The choice of tyrosine kinase inhibitor (ie, standard or high dose imatinib, dasatinib, nilotinib) to use for initial therapy in chronic-phase CML (CML-CP) will not always be obvious. Therapy selection will depend on both clinical and molecular factors, which we will discuss in this review.

Blood ◽  
1999 ◽  
Vol 93 (5) ◽  
pp. 1707-1714 ◽  
Author(s):  
Michael H. Tomasson ◽  
Ifor R. Williams ◽  
Robert Hasserjian ◽  
Chirayu Udomsakdi ◽  
Shannon M. McGrath ◽  
...  

Abstract The TEL/PDGFβR fusion protein is expressed as the consequence of a recurring t(5;12) translocation associated with chronic myelomonocytic leukemia (CMML). Unlike other activated protein tyrosine kinases associated with hematopoietic malignancies, TEL/PDGFβR is invariably associated with a myeloid leukemia phenotype in humans. To test the transforming properties of TEL/PDGFβR in vivo, and to analyze the basis for myeloid lineage specificity in humans, we constructed transgenic mice with TEL/PDGFβR expression driven by a lymphoid-specific immunoglobulin enhancer-promoter cassette. These mice developed lymphoblastic lymphomas of both T and B lineage, demonstrating that TEL/PDGFβR is a transforming protein in vivo, and that the transforming ability of this fusion is not inherently restricted to the myeloid lineage. Treatment of TEL/PDGFβR transgenic animals with a protein tyrosine kinase inhibitor with in vitro activity against PDGFβR (CGP57148) resulted in suppression of disease and a prolongation of survival. A therapeutic benefit was apparent both in animals treated before the development of overt clonal disease and in animals transplanted with clonal tumor cells. These results suggest that small-molecule tyrosine kinase inhibitors may be effective treatment for activated tyrosine kinase–mediated malignancies both early in the course of disease and after the development of additional transforming mutations.


Blood ◽  
1999 ◽  
Vol 93 (5) ◽  
pp. 1707-1714 ◽  
Author(s):  
Michael H. Tomasson ◽  
Ifor R. Williams ◽  
Robert Hasserjian ◽  
Chirayu Udomsakdi ◽  
Shannon M. McGrath ◽  
...  

The TEL/PDGFβR fusion protein is expressed as the consequence of a recurring t(5;12) translocation associated with chronic myelomonocytic leukemia (CMML). Unlike other activated protein tyrosine kinases associated with hematopoietic malignancies, TEL/PDGFβR is invariably associated with a myeloid leukemia phenotype in humans. To test the transforming properties of TEL/PDGFβR in vivo, and to analyze the basis for myeloid lineage specificity in humans, we constructed transgenic mice with TEL/PDGFβR expression driven by a lymphoid-specific immunoglobulin enhancer-promoter cassette. These mice developed lymphoblastic lymphomas of both T and B lineage, demonstrating that TEL/PDGFβR is a transforming protein in vivo, and that the transforming ability of this fusion is not inherently restricted to the myeloid lineage. Treatment of TEL/PDGFβR transgenic animals with a protein tyrosine kinase inhibitor with in vitro activity against PDGFβR (CGP57148) resulted in suppression of disease and a prolongation of survival. A therapeutic benefit was apparent both in animals treated before the development of overt clonal disease and in animals transplanted with clonal tumor cells. These results suggest that small-molecule tyrosine kinase inhibitors may be effective treatment for activated tyrosine kinase–mediated malignancies both early in the course of disease and after the development of additional transforming mutations.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hu Lei ◽  
Han-Zhang Xu ◽  
Hui-Zhuang Shan ◽  
Meng Liu ◽  
Ying Lu ◽  
...  

AbstractIdentifying novel drug targets to overcome resistance to tyrosine kinase inhibitors (TKIs) and eradicating leukemia stem/progenitor cells are required for the treatment of chronic myelogenous leukemia (CML). Here, we show that ubiquitin-specific peptidase 47 (USP47) is a potential target to overcome TKI resistance. Functional analysis shows that USP47 knockdown represses proliferation of CML cells sensitive or resistant to imatinib in vitro and in vivo. The knockout of Usp47 significantly inhibits BCR-ABL and BCR-ABLT315I-induced CML in mice with the reduction of Lin−Sca1+c-Kit+ CML stem/progenitor cells. Mechanistic studies show that stabilizing Y-box binding protein 1 contributes to USP47-mediated DNA damage repair in CML cells. Inhibiting USP47 by P22077 exerts cytotoxicity to CML cells with or without TKI resistance in vitro and in vivo. Moreover, P22077 eliminates leukemia stem/progenitor cells in CML mice. Together, targeting USP47 is a promising strategy to overcome TKI resistance and eradicate leukemia stem/progenitor cells in CML.


2015 ◽  
Vol 4 (2S) ◽  
pp. 17-20
Author(s):  
Mario Annunziata

Imatinib mesylate is a tyrosine kinase inhibitor that has significant efficacy in the treatment of chronic myelogenous leukemia. In general, hematologic and extrahematologic side effects of imatinib therapy are mild to moderate, with the large majority of patients tolerating prolonged periods of therapy. However, a minority of patients are completely intolerant of therapy, while others are able to remain on therapy despite significant side effects. Here, we describe a chronic phase CML patient with pulmonary arterial hypertension, mechanical hearth valve, who experienced extrahematologic adverse event (persistent grade III cutaneous rash, despite two discontinuations of imatinib and using of steroid). Necessitating switch to one of new tyrosine kinase inhibitors, nilotinib, has resulted in complete cytogenetic response and major molecular response, after 3 and 6 months, respectively. No cross-intolerance with imatinib was observed during nilotinib therapy. Besides, this clinical case suggests that warfarin and nilotinib can be used concurrently without the risk of increased anticoagulant effect.


1991 ◽  
Vol 11 (5) ◽  
pp. 2496-2502
Author(s):  
V Lhoták ◽  
P Greer ◽  
K Letwin ◽  
T Pawson

The elk gene encodes a novel receptorlike protein-tyrosine kinase, which belongs to the eph subfamily. We have previously identified a partial cDNA encompassing the elk catalytic domain (K. Letwin, S.-P. Yee, and T. Pawson, Oncogene 3:621-678, 1988). Using this cDNA as a probe, we have isolated cDNAs spanning the entire rat elk coding sequence. The predicted Elk protein contains all the hallmarks of a receptor tyrosine kinase, including an N-terminal signal sequence, a cysteine-rich extracellular domain, a membrane-spanning segment, a cytoplasmic tyrosine kinase domain, and a C-terminal tail. In both amino acid sequence and overall structure, Elk is most similar to the Eph and Eck protein-tyrosine kinases, suggesting that the eph, elk, and eck genes encode members of a new subfamily of receptorlike tyrosine kinases. Among rat tissues, elk expression appears restricted to brain and testes, with the brain having higher levels of both elk RNA and protein. Elk protein immunoprecipitated from a rat brain lysate becomes phosphorylated on tyrosine in an in vitro kinase reaction, consistent with the prediction that the mammalian elk gene encodes a tyrosine kinase capable of autophosphorylation. The characteristics of the Elk tyrosine kinase suggest that it may be involved in cell-cell interactions in the nervous system.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1669-1669
Author(s):  
Franck E. Nicolini ◽  
Françoise Huguet ◽  
Hélène Labussière-Wallet ◽  
Yann Guillermin ◽  
Madeleine Etienne ◽  
...  

Abstract Abstract 1669 Most epidemiologic studies performed in chronic myelogenous leukemia (CML) relate that the disease occurs preferentially in males with a sex ratio of ∼1.2. In addition, CML can be diagnosed in young adults and masculine fertility is a matter of concern, particularly because tyrosine kinase inhibitors (TKI) may impact on spermatogenesis by a selective inhibition of Src kinases, PDGF-R and c-kit. Sperm cryopreservation is recommended by some authors at diagnosis in males that would expect to have children later on. In a retrospective analysis we have analysed the spermograms of 62 chronic phase (CP) and 2 onset blast crisis (BC) CML males referred to our 3 centres between 2001 and 2012, collected at diagnosis before TKI treatment, and we have compared the results obtained to those of 15 healthy volunteer donors from the cryopreservation bank database, after informed consent. In 10 patients we could collect some data for patients being on imatinib mesylate (IM). CML patients had a median age of 31 (16–48) years, significantly younger than that in the control group of healthy donors: 37 (34–45) years (p=0.001). Sokal scores were 24% high, 27% intermediate and 49% low for evaluable patients (13 patients unknown or not available). The median BCR-ABLIS value at diagnosis was 77.65%. Patients had a median duration of 26 (0–38) days of hydroxyurea prior to commencing any TKI and 65% of evaluable patients had HU before TKI. None of the patients got interferon prior to TKI. The semen cryopreservation was performed within a median of 10 (2–102) days after CML diagnosis and after a median abstinence of 5 (0.5–30) days. The median volume of semen obtained in CML patients was 2.95 (0.5–14.9) ml and 3 (1.4–5.3) ml for normal donors (p=0.3). Williams test showed 72 (0–87)% of necrospermia in patients versus 18 (4–32)% in donors (p=0.00003). The median number of spermatozoa obtained was not different in patients [46 (0.03–200) 106/ml] than that in donors [74 (19.2–253) 106/ml] (p=0.24), as well as the number of spermatozoa per ejaculate observed (p=0.49). The motility of spermatozoa at 30 minutes after collection was not different between patients (median = 47.5%) and donors (median = 50%) (p=0.12), however higher numbers of atypical spermatozoa were observed in patients [median = 77.5 (16–100)%] rather than in donors [median = 45% (22–89)%], p=0.008, and the multiple abnormalities index (MAI) was significantly higher in patients [median = 1.99 (1.14–2.7)] than that in donors [median = 1.33 (1.09–1.55)], p=0.00006. There was no correlation between age at diagnosis, Sokal index and the number of spermatozoa per ml obtained (p=0.7 and 0.21 respectively). Ten CP CML patients had spermograms after a median of 1440 (9–1456) days of IM treatment and the results obtained were compared to i) the results of each individual patient at CP diagnosis and ii) to the results of healthy comparators. In comparison to the characteristics observed at diagnosis, the semen volume (median = 3.1 ml), Williams test (median = 65%), the motility at 30 minutes (median = 37.5%) and the MAI (median = 1.71) were not different (p=ns for all), however, the numbers of spermatozoa (median = 14.9 106/ml and = 37.05 ml per ejaculate) collected on IM were significantly lower (p=0.014 and p=0.045 respectively). The different parameters evaluated on IM were compared to those of normal controls and showed significant alterations. The semen volume was not different (p=0.94), neither the motility of spermatozoa (p=0.24), but the Williams test was highly perturbed on IM [median 65 (24–79)% versus 18 (4–32)% in donors] p=0.00003, as well as the numbers of spermatozoa as 106 per ml, collected on IM [median 14.9 (0.67–179)) versus normal [74 (19.2–253)], p=0.0036 or as 106 per ejaculate collected on IM [median 37.5 (2.68–572.8)) versus normal [149 (30–535.3)], p=0.026. Atypical forms were significantly more abundant on IM [median = 80 (68–90)%] versus healthy controls [median = 45% (22–89)], p=0.0058. Finally, the MAI was severely altered on IM [median = 1.71 (1.61–1.98)] versus normal individuals [median = 1.33 (1.09–1.55)], p=0.00013. In conclusion, this work demonstrates the existence of significant sperm alterations in young males with CML at diagnosis of undetermined origin, prior to any treatment. These alterations persist on IM treatment and little is know about the impact of second generation TKI. Thus the most appropriate approach remains a matter of debate in thus setting. Disclosures: Nicolini: Novartis, Bristol Myers-Squibb, Pfizer, ARIAD, and Teva: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Huguet:Novartis, BMS: Speakers Bureau. Michallet:Novartis, Pfizer, Teva, Genzyme, Janssen Cilag, BMS, Merck, Pfizer, Gilead, Alexion: Consultancy, Speakers Bureau. Etienne:Novartis, Pfizer, speaker for Novartis, BMS: Consultancy.


1986 ◽  
Vol 6 (12) ◽  
pp. 4467-4477
Author(s):  
J A Cooper ◽  
C S King

Phosphorylation of pp60c-src at Tyr-527, six residues from the carboxy terminus, has been implicated in regulation of the protein-tyrosine kinase activity of pp60c-src. Here we show that dephosphorylation of pp60c-src by phosphatase treatment in vitro caused a 10- to 20-fold increase in pp60c-src protein-tyrosine kinase activity. Binding of specific antibody to the region of pp60c-src which contains phosphotyrosine-527 also increased kinase activity. Each treatment increased phosphorylation of added substrates and of Tyr-416 within pp60c-src by a similar mechanism that involved altered interactions with ATP and increased catalytic rate. We suggest that the phosphorylated carboxy terminus acts as an inhibitor of the protein kinase domain of pp60c-src, unless its conformation is altered by either dephosphorylation or antibody binding. The antibody additionally stimulated the phosphorylation of forms of pp60c-src that had reduced gel mobility, much like those phosphorylated in kinase reactions containing pp60c-src activated by polyomavirus medium tumor antigen. These in vitro experiments provide models for the activation of pp60c-src in cells transformed by polyomavirus. We also show that autophosphorylation of pp60c-src at Tyr-527 occurs only to a very limited extent in vitro, even when Tyr-527 is made available for phosphorylation by treatment with phosphatase. This suggests that other protein-tyrosine kinases may normally phosphorylate Tyr-527 and regulate pp60c-src in the cell.


Blood ◽  
1995 ◽  
Vol 86 (12) ◽  
pp. 4389-4399 ◽  
Author(s):  
ZK Indik ◽  
JG Park ◽  
S Hunter ◽  
AD Schreiber

Because hematopoietic cells express multiple Fc gamma receptor isoforms, the role of the individual Fc gamma receptors in phagocytosis has been difficult to define. Transfection of Fc gamma receptors into COS-1 cells, which lack endogeneous Fc gamma receptors but have phagocytic potential, has proved valuable for the study of individual Fc gamma receptor function. Using this model system, we have established that a single class of human Fc gamma receptor mediates phagocytosis in the absence of other Fc receptors and that isoforms from each Fc gamma receptor class mediate phagocytosis, although the requirements for phagocytosis differ. In investigating the relationship between structure and function for Fc gamma receptor mediated phagocytosis, the importance of the cytoplasmic tyrosines of the receptor or its associated gamma chain has been established. For example, two cytoplasmic YXXL sequences, in a configuration similar to the conserved tyrosine-containing motif found in Ig gene family receptors, are important for phagocytosis by the human Fc gamma receptor, Fc gamma RIIA. Fc gamma RI and Fc gamma RIIIA do not possess cytoplasmic tyrosines but transmit a phagocytic signal through interaction with an associated gamma subunit that contains two YXXL sequences in a conserved motif required for phagocytosis. The human Fc gamma RII isoforms Fc gamma RIIB1 and Fc gamma RIIB2 do not induce phagocytosis and have only a single YXXL sequence. Cross-linking the phagocytic Fc gamma receptors induces tyrosine phosphorylation of either Fc gamma RIIA or the gamma chain, and treatment with tyrosine kinase inhibitors reduces both phagocytosis and phosphorylation of the receptor tyrosine residues. Activation of protein tyrosine kinases follows Fc gamma receptor engagement of IgG-coated cells. The data indicate that coexpression of the protein tyrosine kinase Syk, which is associated with the gamma chain in monocytes/macrophages, is important for phagocytosis mediated by Fc gamma RI and Fc gamma RIIIA. Furthermore, phosphatidylinositol-3 kinase is required for phagocytosis mediated by Fc gamma RIIA as well as for phagocytosis mediated by Fc gamma RI/gamma and Rc gamma RIIIA/gamma.


Blood ◽  
1997 ◽  
Vol 90 (12) ◽  
pp. 4947-4952 ◽  
Author(s):  
Martin Carroll ◽  
Sayuri Ohno-Jones ◽  
Shu Tamura ◽  
Elisabeth Buchdunger ◽  
Jürg Zimmermann ◽  
...  

Abstract CGP 57148 is a compound of the 2-phenylaminopyrimidine class that selectively inhibits the tyrosine kinase activity of the ABL and the platelet-derived growth factor receptor (PDGFR) protein tyrosine kinases. We previously showed that CGP 57148 selectively kills p210BCR-ABL–expressing cells. To extend these observations, we evaluated the ability of CGP 57148 to inhibit other activated ABL tyrosine kinases, including p185BCR-ABL and TEL-ABL. In cell-based assays of ABL tyrosine phosphorylation, inhibition of ABL kinase activity was observed at concentrations similar to that reported for p210BCR-ABL. Consistent with the in vitro profile of this compound, the growth of cells expressing activated ABL protein tyrosine kinases was inhibited in the absence of exogenous growth factor. Growth inhibition was also observed with a p185BCR-ABL–positive acute lymphocytic leukemia (ALL) cell line generated from a Philadelphia chromosome–positive ALL patient. As CGP 57148 inhibits the PDGFR kinase, we also showed that cells expressing an activated PDGFR tyrosine kinase, TEL-PDGFR, are sensitive to this compound. Thus, this compound may be useful for the treatment of a variety of BCR-ABL–positive leukemias and for treatment of the subset of chronic myelomonocytic leukemia patients with a TEL-PDGFR fusion protein.


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