ORCID Profile
0000-0002-0910-3730
Current Organisation
South Australian Health and Medical Research Institute Limited
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Publisher: American Society of Hematology
Date: 03-2008
DOI: 10.1182/BLOOD-2007-07-104281
Abstract: Imatinib inhibits tyrosine kinases important in osteoclast (c-Fms) and osteoblast (platelet-derived growth factor receptor [PDGF-R], c-Abl) function, suggesting that long-term therapy may alter bone homeostasis. To investigate this question, we measured the trabecular bone volume (TBV) in iliac crest bone biopsies taken from chronic myeloid leukemia (CML) patients at diagnosis and again after 2 to 4 years of imatinib therapy. Half the patients (8 of 17) showed a substantive increase in TBV ( 2-fold), after imatinib therapy, with the TBV in the posttreatment biopsy typically surpassing the normal upper limit for the patient's age group. Imatinib-treated patients exhibited reduced serum calcium and phosphate levels with hypophosphatemia evident in 53% (9 of 17) of patients. In vitro, imatinib suppressed osteoblast proliferation and stimulated osteogenic gene expression and mineralized-matrix production by inhibiting PDGF receptor function. In PDGF-stimulated cultures, imatinib dose-dependently inhibited activation of Akt and Crk-L. Using pharmacologic inhibitors, inhibition of PI3-kinase/Akt activation promoted mineral formation, suggesting a possible molecular mechanism for the imatinib-mediated increase in TBV in vivo. Further investigation is required to determine whether the increase in TBV associated with imatinib therapy may represent a novel therapeutic avenue for the treatment of diseases that are characterized by generalized bone loss.
Publisher: American Society of Hematology
Date: 26-07-2018
DOI: 10.1182/BLOOD-2016-09-739086
Abstract: Ponatinib continued to provide deep, durable responses in heavily pretreated patients with CP-CML. Tolerability was acceptable in this heavily pretreated population with 5 years of follow-up.
Publisher: Springer Science and Business Media LLC
Date: 23-03-2018
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 30-04-2016
Publisher: American Society of Hematology
Date: 25-05-2023
DOI: 10.1182/BLOODADVANCES.2022008854
Abstract: Dysregulation of immune-checkpoint receptors has been reported at diagnosis of chronic myeloid leukemia (CML), however, their role in the maintenance of remission after tyrosine kinase inhibitor (TKI) cessation is unclear. We assessed programmed cell death-1 (PD-1), T-cell immunoglobulin, and mucin-domain containing protein-3 (TIM-3), cytotoxic T-lymphocyte–associated protein-4 (CTLA-4), lymphocyte-activation gene-3 (LAG-3), and T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domains (TIGIT) expression on T-cell subsets, regulatory T cells (T-regs), and natural killer (NK) cells at the time of TKI cessation in 44 patients (22 patients sustained treatment-free remission [TFR] and 22 experienced molecular relapse [MolR]). We confirmed our previous finding that absolute numbers of T-regs are increased in patients who experienced MolR compared with those who sustained TFR. The immune-checkpoint receptors PD-1, CTLA-4, LAG-3, and TIGIT on T or NK cells were not differentially expressed between the MolR and TFR groups. However, TIM-3 was consistently upregulated on bulk T cells (CD3+) and T-cell subsets including, CD4+ T cells, CD8+ T cells, and T-regs, in patients who relapsed in comparison with those who maintained TFR after discontinuation. Furthermore, gene expression analysis from publicly available data sets showed increased TIM-3 expression on CML stem cells compared with normal hematopoietic stem cells. These findings suggest that among the targetable immune-checkpoint molecules, TIM-3 blockade may potentially improve effector immune response in patients with CML stopping TKI, while concomitantly targeting leukemic stem cells and could be a promising therapeutic strategy for preventing relapse after cessation of TKI in patients with CML.
Publisher: Springer Science and Business Media LLC
Date: 21-12-2015
DOI: 10.1038/LEU.2015.352
Publisher: Springer Science and Business Media LLC
Date: 15-02-2013
DOI: 10.1038/LEU.2013.47
Publisher: Springer Science and Business Media LLC
Date: 19-05-2009
DOI: 10.1007/S12185-009-0327-0
Abstract: Nilotinib is a second-generation BCR-ABL kinase inhibitor with improved potency and selectivity compared to imatinib. A Phase I/II dose-escalation study was designed to evaluate the efficacy, safety, and pharmacokinetics of nilotinib in Japanese patients with imatinib-resistant or -intolerant Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML) or relapsed/refractory Ph+ acute lymphoblastic leukemia (ALL). A total of 34 patients were evaluated in this analysis and had a median duration of drug exposure of 293 (range 13-615) days. All 6 CML-CP patients without complete hematologic response (CHR) at baseline rapidly achieved CHR. A major cytogenetic response was achieved in 94% of patients with CML-CP, including a complete cytogenetic response in 69%. A major molecular response was achieved by 56%. These responses were also observed in patients with CML in advanced stages and Ph+ ALL. Non-hematologic adverse events were mostly mild to moderate. Grade 3 or 4 neutropenia and thrombocytopenia occurred in 50 and 28% of patients, respectively. Overall, the results of this study suggest that nilotinib induced significant responses in imatinib-resistant or -intolerant patients with CML-CP and CML in advanced stages and Ph+ ALL. The results of this study confirmed the efficacy and safety of nilotinib in Japanese patients.
Publisher: Springer Science and Business Media LLC
Date: 26-03-2012
DOI: 10.1038/LEU.2012.85
Abstract: In the face of competing first-line treatment options for CML, early prediction of prognosis on imatinib is desirable to assure favorable survival or otherwise consider the use of a second-generation tyrosine kinase inhibitor (TKI). A total of 1303 newly diagnosed imatinib-treated patients (pts) were investigated to correlate molecular and cytogenetic response at 3 and 6 months with progression-free and overall survival (PFS, OS). The persistence of BCR-ABL transcript levels >10% according to the international scale (BCR-ABL(IS)) at 3 months separated a high-risk group (28% of pts 5-year OS: 87%) from a group with >1-10% BCR-ABL(IS) (41% of pts 5-year OS: 94% P=0.012) and from a group with ≤1% BCR-ABL(IS) (31% of pts 5-year OS: 97% P=0.004). Cytogenetics identified high-risk pts by >35% Philadelphia chromosome-positive metaphases (Ph+, 27% of pts 5-year OS: 87%) compared with ≤35% Ph+ (73% of pts 5-year OS: 95% P=0.036). At 6 months, >1% BCR-ABL(IS) (37% of pts 5-year OS: 89%) was associated with inferior survival compared with ≤1% (63% of pts 5-year OS: 97% P 0% Ph+ (34% of pts 5-year OS: 91%) compared with 0% Ph+ (66% of pts 5-year OS: 97% P=0.015). Treatment optimization is recommended for pts missing these landmarks.
Publisher: American Society of Hematology
Date: 30-05-2013
DOI: 10.1182/BLOOD-2013-03-490003
Abstract: As a group of more than 100 experts in chronic myeloid leukemia (CML), we draw attention to the high prices of cancer drugs, with the particular focus on the prices of approved tyrosine kinase inhibitors for the treatment of CML. This editorial addresses the multiple factors involved in cancer drug pricing and their impact on in idual patients and health care policies, and argues for the need to (1) lower the prices of cancer drugs to allow more patients to afford them and (2) maintain sound long-term health care policies.
Publisher: Public Library of Science (PLoS)
Date: 03-01-2017
Publisher: Wiley
Date: 26-10-2010
Publisher: Springer Science and Business Media LLC
Date: 18-05-2012
DOI: 10.1038/LEU.2012.134
Abstract: Evaluating Nilotinib Efficacy and Safety in Clinical Trials Newly Diagnosed Patients compares nilotinib and imatinib in patients with newly diagnosed chronic myeloid leukemia in chronic phase (CML-CP). With a minimum follow-up of 3 years, major molecular response, molecular response of BCR-ABL≤ 0.01% expressed on the international scale (BCR-ABL(IS) MR(4)) and BCR-ABL(IS)≤ 0.0032% (MR(4.5)) rates were significantly higher with nilotinib compared with imatinib, and differences in the depth of molecular response between nilotinib and imatinib have increased over time. No new progressions occurred on treatment since the 2-year analysis. Nilotinib was associated with a significantly lower probability of progression to accelerated phase/blast crisis vs imatinib (two (0.7%) progressions on nilotinib 300 mg twice daily, three (1.1%) on nilotinib 400 mg twice daily and 12 (4.2%) on imatinib). When considering progressions occurring after study treatment discontinuation, the advantage of nilotinib over imatinib in preventing progression remained significant (nine (3.2%) progressions on nilotinib 300 mg twice daily, six (2.1%) on nilotinib 400 mg twice daily and 19 (6.7%) on imatinib). Both nilotinib and imatinib were well tolerated, with minimal changes in safety over time. Nilotinib continues to demonstrate superior efficacy in all key response and outcome parameters compared with imatinib for the treatment of patients with newly diagnosed CML-CP.
Publisher: Springer Science and Business Media LLC
Date: 02-07-2015
DOI: 10.1007/S12185-015-1824-Y
Abstract: Imatinib is generally well tolerated, but gastric antral vascular ectasia (GAVE) remains a rare but significant complication of imatinib therapy. Whilst this complication has been described in other disease settings, only one other case of GAVE has been reported in a chronic myeloid leukaemia (CML) patient receiving imatinib. Herein, we present three CML patients with GAVE complicating imatinib therapy. In all cases, GAVE resolved only with cessation of imatinib. This confirms a causal relationship between GAVE and imatinib. GAVE should be considered as a possible cause of anaemia and upper gastrointestinal bleeding in patients receiving imatinib therapy.
Publisher: Elsevier BV
Date: 02-2009
DOI: 10.1016/J.EXPHEM.2008.09.013
Abstract: Dasatinib (BMS-354825) is a small molecule Src/Abl tyrosine kinase inhibitor approved for the treatment of chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia. Members of the Src family of kinases are involved in the induction of innate and adaptive immunity. The purpose of this study was to evaluate the inhibitory action of dasatinib on antigen-specific CD8(+) and CD4(+) T-cell function, as well as natural killer (NK) cell cytotoxicity. To assess dasatinib-mediated inhibition of antigen-specific T-cell proliferation, transgenic CD4(+) and CD8(+) T cells specific for ovalbumin were utilized. Endogenous CD4(+) and CD8(+) T-cell responses were determined following immunization of dasatinib-treated or control mice with a nonreplicating recombinant virus. Clearance of the RMA-S cells, a major histocompatibility complex (MHC) class I-deficient thymoma sensitive to NK-cell lysis, was analyzed in mice undergoing dasatinib treatment. Dasatinib inhibited antigen-specific proliferation of murine CD4(+) and CD8(+) transgenic T cells in vitro and in vivo. Endogenous antigen-specific helper T-cell recall responses and induction of T-cell-mediated cytotoxicity following immunization with a nonreplicating recombinant virus were also inhibited. So to was the ability of NK cells to eliminate MHC class I-deficient cells in vivo. These findings suggest that dasatinib has the potential to modulate the host immune response at clinical doses and highlights scope for off target applications, e.g., therapeutic immunosuppression in the context of autoimmune pathogenesis and allogeneic tissue transplantation.
Publisher: Springer Science and Business Media LLC
Date: 09-10-2014
Abstract: The efflux transporters adenosine triphosphate (ATP)-binding cassette (ABC)B1 and ABCG2 have been demonstrated to interact with the tyrosine kinase inhibitors (TKIs) imatinib, nilotinib, and dasatinib. However, although some studies conclude that TKIs are substrates of one or both transporters, other studies demonstrate only an inhibitory function. This variation is probably due to differences in the concentration of TKIs assayed and the experimental systems used. This article examines the evidence for clinically relevant interactions between three currently approved TKIs and ABCB1/ABCG2.
Publisher: Springer Science and Business Media LLC
Date: 25-06-2013
DOI: 10.1038/BJC.2013.318
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 12-09-2014
Publisher: American Society of Clinical Oncology (ASCO)
Date: 10-12-2012
Abstract: The association between initial molecular response and longer-term outcomes with nilotinib was examined. Patients with imatinib-resistant or -intolerant chronic myeloid leukemia in chronic phase from the phase II nilotinib registration study with available postbaseline BCR-ABL1 transcript assessments were included (N = 237). BCR-ABL1 transcript levels (International Scale [IS]) at 3 months correlated with complete cytogenetic response (CCyR) by 24 months. Patients with BCR-ABL1 (IS) of 1% to ≤ 10% at 3 months with nilotinib had higher cumulative incidence of CCyR by 24 months than patients with BCR-ABL1 (IS) of 10% (53% v 16%). BCR-ABL1 (IS) at 3 months predicted major molecular response (MMR) by 24 months. Cumulative incidence of MMR by 24 months for patients with BCR-ABL1 (IS) of 0.1% to ≤ 1%, 1% to ≤ 10%, and 10% was 65%, 27%, and 9%, respectively. These differences were observed for patients with or without baseline BCR–ABL1 mutations and for those with imatinib resistance or intolerance. Estimated event-free survival (EFS) rates at 24 months decreased with higher transcript levels at 3 months patients with BCR-ABL1 (IS) of ≤ 1% had an estimated 24-month EFS rate of 82%, compared with 70% for patients with BCR-ABL1 (IS) of 1% to ≤ 10% and 48% for patients with BCR-ABL1 (IS) of 10%. Patients with BCR-ABL1 (IS) of 10% at 3 months had a lower cumulative incidence of CCyR and MMR and lower rates of EFS versus patients with BCR-ABL1 (IS) of ≤ 10%. Prospective studies may determine whether close monitoring or alternative therapies are warranted for patients with minimal initial molecular response.
Publisher: Wiley
Date: 04-2009
DOI: 10.1002/CNCR.24155
Abstract: Dasatinib is a highly potent Bcr-Abl inhibitor that is approved for the treatment of imatinib-resistant or -intolerant chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia. Across a series of phase 2 and 3 trials, dasatinib was associated with durable treatment responses in all phases of the disease and was well tolerated. For this article, the authors reviewed available information on specific side effects associated with the use of dasatinib. On the basis of more than 2 years' experience of dasatinib treatment during clinical trials, they provide practical recommendations for side-effect management.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2010
Publisher: Wiley
Date: 27-03-2019
DOI: 10.1111/BJH.15894
Publisher: American Society of Hematology
Date: 05-02-2015
DOI: 10.1182/BLOOD-2014-07-590315
Abstract: Using imatinib to treat CML first-line, with selective nilotinib switching, leads to excellent molecular response and survival. This strategy may be preferable to universal first-line use of more potent agents, considering efficacy, toxicity, and economic factors.
Publisher: Informa UK Limited
Date: 2008
Publisher: Springer Science and Business Media LLC
Date: 24-05-2012
Publisher: Wiley
Date: 30-04-2020
DOI: 10.1111/BJH.16718
Abstract: There is currently no biomarker that reliably predicts treatment‐free remission (TFR) in chronic myeloid leukaemia (CML). We characterised effector and suppressor immune responses at the time of tyrosine kinase inhibitor (TKI) cessation in patients from the CML8 and CML10 clinical studies. Natural killer (NK) cells with increased expression of activating NK receptors were higher in patients who achieved TFR. There was no difference in the proportion of CD4 + or CD8 + T cells. Furthermore, we found that FoxP3 + regulatory T cells (T reg) and monocytic myeloid‐derived suppressor cells (Mo‐MDSCs) were concomitantly decreased in TFR patients, suggesting that the effector and suppressor arms of the immune system work in concert to mediate TFR. A discovery cohort (CML10) was used to generate a predictive model, using logistic regression. Patients classified into the high‐risk group were more likely to relapse when compared with the low‐risk group (HR 7·4, 95% CI 2·9‐19·1). The model was successfully validated on the independent CML8 cohort (HR 8·3, 95% CI 2·2–31·3). Effective prediction of TFR success may be obtained with an effector‐suppressor score, calculated using absolute NK cell, T reg, and Mo‐MDSC counts, at TKI cessation, reflecting the contribution of both immune suppressors and effectors in the immunobiology underlying successful TFR.
Publisher: Cold Spring Harbor Laboratory
Date: 17-07-2018
Publisher: Massachusetts Medical Society
Date: 11-09-2014
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 08-08-2013
Publisher: American Society of Hematology
Date: 20-02-2014
DOI: 10.1182/BLOOD-2012-12-475194
Abstract: IL-3 receptor α (CD123) expression is elevated in CML progenitor and stem cells compared with healthy donors. CD123 monoclonal antibody targeting represents a novel, potentially clinically relevant approach to deplete CML progenitor and stem cells.
Publisher: Springer Science and Business Media LLC
Date: 16-09-2010
DOI: 10.1038/LEU.2010.197
Abstract: Previous experience in the treatment of chronic myeloid leukaemia (CML) has shown that the achievement of clinical, morphological and cytogenetic remission does not indicate eradication of the disease. A complete molecular response (CMR no detectable BCR-ABL mRNA) represents a deeper level of response, but even CMR is not a guarantee of elimination of the leukaemia, because the significance of CMR is determined by the detection limit of the assay that is used. Two studies of imatinib cessation in CMR are underway, cumulatively involving over 100 patients. The current estimated rate of stable CMR after stopping imatinib is approximately 40%, but the duration of follow-up is relatively short. The factors that determine relapse risk are yet to be identified. The intrinsic capacity of any residual leukaemia [corrected] cells to proliferate following the withdrawal of treatment may be important, but there may also be a role for immunological suppression of the leukaemia [corrected] clone. No currently available test can formally prove that the leukaemic clone is eradicated. Here we discuss the sensitive measurement of minimal residual disease, and speculate on the biology of BCR-ABL-positive cells that may persist after effective therapy of CML.
Publisher: Springer Science and Business Media LLC
Date: 15-08-2014
DOI: 10.1038/BCJ.2014.60
Publisher: American Society of Hematology
Date: 03-05-2012
DOI: 10.1182/BLOOD-2011-11-393041
Abstract: Rising BCR-ABL1 transcripts indicate potential loss of imatinib response in CML. We determined whether the BCR-ABL1 doubling time could distinguish nonadherence from resistance as the cause of lost response. Distinct groups were examined: (1) acquired clinical resistance because of blast crisis and/or BCR-ABL1 mutations and (2) documented imatinib discontinuation/interruption. Short doubling times occurred with blast crisis (median, 9.0 days range, 6.1-17.6 days n = 12 patients), relapse after imatinib discontinuation in complete molecular response (median, 9.0 days range, 6.9-26.5 days n = 17), and imatinib interruption during an entire measurement interval (median, 9.4 days range, 4.2-17.6 days n = 12 P = .72). Whereas these doubling times were consistently short and indicated rapid leukemic expansion, fold rises were highly variable: 71-, 9.5-, and 10.5-fold, respectively. The fold rise depended on the measurement interval, whereas the doubling time was independent of the interval. Longer doubling times occurred for patients with mutations who maintained chronic phase (CP: median, 48 days range, 17.3-143 days n = 29 P .0001). Predicted short and long doubling times were validated on an independent cohort monitored elsewhere. The doubling time revealed major differences in kinetics according to clinical context. Long doubling times observed with mutations in CP allow time for intervention. A short doubling time for a patient in CP should raise the suspicion of nonadherence.
Publisher: Springer Science and Business Media LLC
Date: 24-04-2012
DOI: 10.1038/BJC.2012.173
Publisher: Informa UK Limited
Date: 11-12-2015
Publisher: American Society of Clinical Oncology (ASCO)
Date: 07-2008
Abstract: Dasatinib is a BCR-ABL inhibitor, 325-fold more potent than imatinib against unmutated BCR-ABL in vitro. Phase II studies have demonstrated efficacy and safety with dasatinib 70 mg twice daily in chronic-phase (CP) chronic myelogenous leukemia (CML) after imatinib treatment failure. In phase I, responses occurred with once-daily administration despite only intermittent BCR-ABL inhibition. Once-daily treatment resulted in less toxicity, suggesting that toxicity results from continuous inhibition of unintended targets. Here, a dose- and schedule-optimization study is reported. In this open-label phase III trial, 670 patients with imatinib-resistant or -intolerant CP-CML were randomly assigned 1:1:1:1 between four dasatinib treatment groups: 100 mg once daily, 50 mg twice daily, 140 mg once daily, or 70 mg twice daily. With minimum follow-up of 6 months (median treatment duration, 8 months range, 1 to 15 months), marked and comparable hematologic (complete, 86% to 92%) and cytogenetic (major, 54% to 59% complete, 41% to 45%) response rates were observed across the four groups. Time to and duration of cytogenetic response were similar, as was progression-free survival (8% to 11% of patients experienced disease progression or died). Compared with the approved 70-mg twice-daily regimen, dasatinib 100 mg once daily resulted in significantly lower rates of pleural effusion (all grades, 7% v 16% P = .024) and grade 3 to 4 thrombocytopenia (22% v 37% P = .004), and fewer patients required dose interruption (51% v 68%), reduction (30% v 55%), or discontinuation (16% v 23%). Dasatinib 100 mg once daily retains the efficacy of 70 mg twice daily with less toxicity. Intermittent target inhibition with tyrosine kinase inhibitors may preserve efficacy and reduce adverse events.
Publisher: American Society of Hematology
Date: 08-08-2013
DOI: 10.1182/BLOOD-2013-05-501569
Abstract: Advances in chronic myeloid leukemia treatment, particularly regarding tyrosine kinase inhibitors, mandate regular updating of concepts and management. A European LeukemiaNet expert panel reviewed prior and new studies to update recommendations made in 2009. We recommend as initial treatment imatinib, nilotinib, or dasatinib. Response is assessed with standardized real quantitative polymerase chain reaction and/or cytogenetics at 3, 6, and 12 months. BCR-ABL1 transcript levels ≤10% at 3 months, % at 6 months, and ≤0.1% from 12 months onward define optimal response, whereas % at 6 months and % from 12 months onward define failure, mandating a change in treatment. Similarly, partial cytogenetic response (PCyR) at 3 months and complete cytogenetic response (CCyR) from 6 months onward define optimal response, whereas no CyR (Philadelphia chromosome–positive [Ph+] %) at 3 months, less than PCyR at 6 months, and less than CCyR from 12 months onward define failure. Between optimal and failure, there is an intermediate warning zone requiring more frequent monitoring. Similar definitions are provided for response to second-line therapy. Specific recommendations are made for patients in the accelerated and blastic phases, and for allogeneic stem cell transplantation. Optimal responders should continue therapy indefinitely, with careful surveillance, or they can be enrolled in controlled studies of treatment discontinuation once a deeper molecular response is achieved.
Publisher: American Society of Hematology
Date: 25-07-2013
DOI: 10.1182/BLOOD-2013-02-483750
Abstract: Approximately 40% of patients with undetectable minimal residual disease on imatinib can stop treatment without loss of molecular response. Patients in treatment-free remission still have detectable BCR-ABL DNA several years after stopping imatinib.
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.CANCERGEN.2017.07.008
Abstract: We report a novel somatic mutation in the kinase domain of JAK2 (R938Q) in a high-risk pediatric case of B-cell acute lymphoblastic leukemia (ALL). The patient developed on-therapy relapse at 12 months, and interestingly, the JAK2 locus acquired loss of heterozygosity during treatment resulting in 100% mutation load. Furthermore, we show that primary ALL mononuclear cells harboring the JAK2 R938Q mutation display reduced sensitivity to the JAK1/2 ATP-competitive inhibitor ruxolitinib in vitro, compared to ALL cells that carry a more common JAK2 pseudokinase domain mutation. Our findings are in line with previous reports that demonstrate that mutations within the kinase domain of JAK2 are associated with resistance to type I JAK inhibitors. Importantly, given the recent inclusion of ruxolitinib in trial protocols for children with JAK pathway alterations, we predict that inter-patient genetic variability may result in suboptimal responses to JAK inhibitor therapy in a subset of cases. The need for alternate targeted and/or combination therapies for patients who display inherent or developed resistance to JAK inhibitor therapy will be warranted, and we propose that kinase-mutants less sensitive to type I JAK inhibitors may present a currently unexplored platform for investigation of improved therapies.
Publisher: American Society of Hematology
Date: 03-12-2009
DOI: 10.1182/BLOOD-2009-04-214221
Abstract: Dasatinib is a BCR-ABL inhibitor with 325-fold higher potency than imatinib against unmutated BCR-ABL in vitro. Imatinib failure is commonly caused by BCR-ABL mutations. Here, dasatinib efficacy was analyzed in patients recruited to phase 2/3 trials with chronic-phase chronic myeloid leukemia with or without BCR-ABL mutations after prior imatinib. Among 1043 patients, 39% had a preexisting BCR-ABL mutation, including 48% of 805 patients with imatinib resistance or suboptimal response. Sixty-threedifferent BCR-ABL mutations affecting 49 amino acids were detected at baseline, with G250, M351, M244, and F359 most frequently affected. After 2 years of follow-up, dasatinib treatment of imatinib-resistant patients with or without a mutation resulted in notable response rates (complete cytogenetic response: 43% vs 47%) and durable progression-free survival (70% vs 80%). High response rates were achieved with different mutations except T315I, including highly imatinib-resistant mutations in the P-loop region. Impaired responses were observed with some mutations with a dasatinib median inhibitory concentration (IC50) greater than 3nM among patients with mutations with lower or unknown IC50, efficacy was comparable with those with no mutation. Overall, dasatinib has durable efficacy in patients with or without BCR-ABL mutations. All trials were registered at www.clinicaltrials.gov as NCT00123474, NCT00101660, and NCT00103844.
Publisher: American Society of Hematology
Date: 05-02-2019
DOI: 10.1182/BLOODADVANCES.2018027516
Abstract: Bone marrow fibrosis may be a late reversible toxicity of high-dose imatinib therapy in chronic myeloid leukemia.
Publisher: Informa UK Limited
Date: 06-06-2020
Publisher: Elsevier BV
Date: 06-2008
DOI: 10.1016/J.CLIM.2008.02.006
Abstract: Dasatinib (BMS-354825) is a Src/ABL tyrosine kinase inhibitor currently approved for the treatment of chronic myeloid leukemia. Dasatinib has increased potency against ABL compared to the current therapy imatinib, and is effective in many cases where disease is resistant to imatinib. Dasatinib also inhibits many Src-family tyrosine kinases. We have demonstrated in this study that dasatinib is able to block the function of normal human T-lymphocytes in vitro at clinically relevant concentrations. T-cell functions including proliferation, activation and cytokine production were all uniformly inhibited in the presence of dasatinib. We also demonstrated inhibition of TCR signalling through Src-family kinase LCK, and predicted that inhibition of LCK and other kinases involved in T-cell signalling by dasatinib is responsible for the suppression of T-cell function. These findings raise the concern about potential T-cell inhibition in patients taking dasatinib, and suggest a possible application for the treatment of T-cell mediated immune disorders.
Publisher: Springer Science and Business Media LLC
Date: 24-06-2017
DOI: 10.1038/LEU.2016.179
Abstract: Tyrosine kinase inhibitor (TKI) therapy results in excellent responses in the majority of patients with chronic myeloid leukaemia. First-line imatinib treatment, with selective switching to nilotinib when patients fail to meet specific molecular targets or for imatinib intolerance, results in excellent overall molecular responses and survival. However, this strategy is less effective in cases of primary imatinib resistance moreover, 25% of patients develop secondary resistance such that 20-35% of patients initially treated with imatinib will eventually experience treatment failure. Early identification of these patients is of high clinical relevance. Since the drug efflux transporter ABCB1 has previously been implicated in TKI resistance, we determined if early increases in ABCB1 mRNA expression (fold change from diagnosis to day 22 of imatinib therapy) predict for patient response. Indeed, patients exhibiting a high fold rise (⩾2.2, n=79) were significantly less likely to achieve early molecular response (BCR-ABL1
Publisher: American Society of Clinical Oncology (ASCO)
Date: 10-02-2011
Abstract: Chronic myeloid leukemia (CML) has been a model disease in the development of targeted therapies. After nearly 40 years of the recognition of the chromosomal abnormality that defines CML, specific therapy was developed, initially with imatinib mesylate, which has transformed our treatment algorithms and has changed the natural history of the disease. Today, most patients have the expectation of a favorable outcome when treated with standard-dose imatinib. However, a significant proportion of patients do not achieve the optimal desirable outcome. Effective salvage therapy followed the recognition of some of the most common mechanisms of resistance. More recently, the focus has turned to new areas of research and medical need, such as improving the front-line therapy to minimize the risk of resistance, to fight the most resistant mutant forms of BCR-ABL, and to eliminate minimal residual disease with the goal of achieving total elimination of the disease and treatment discontinuation. In this review, we analyze the current status of therapy of CML, and we discuss some of the most relevant clinical questions that we face today.
Publisher: Elsevier BV
Date: 11-2017
Publisher: Wiley
Date: 10-11-2020
DOI: 10.1111/BJH.17111
Publisher: American Society of Hematology
Date: 02-07-2015
Publisher: Wiley
Date: 21-06-2022
DOI: 10.1111/BJH.18323
Abstract: Recent approval of asciminib, a novel “specifically targeting the ABL myristoyl pocket” (STAMP) BCR‐ABL1 inhibitor, for the treatment of chronic myeloid leukaemia (CML) patients who have either failed ≥2 lines of therapy or have the T315I mutation, has provided clinicians with a wider selection of potentially effective treatment options. Asciminib has the attractive twin attributes of high potency directed against BCR‐ABL1 and good tolerability based on its limited off‐target effects. However, it is unclear exactly where asciminib will be positioned amongst the other available tyrosine kinase inhibitors (TKIs), especially ponatinib which is also available for the same indications. There are many questions yet to be answered with regard to the optimal use of asciminib which include its role in the first‐ and second‐line settings, combination therapy with other TKIs, and effectiveness in advanced phase CML. In this review, we discuss the available data on asciminib while exploring a number of clinical trials in progress. Finally, we provide our opinion based on the current data about where asciminib is most likely to be the optimal choice, which will hopefully assist clinicians with therapy selection.
Publisher: American Society of Hematology
Date: 08-03-2012
DOI: 10.1182/BLOOD-2011-08-375535
Abstract: Specific imatinib-resistant BCR-ABL1 mutations (Y253H, E255K/V, T315I, F317L, and F359V/C) predict failure of second-line nilotinib or dasatinib therapy in patients with chronic myeloid leukemia however, such therapy also fails in approximately 40% of patients in the chronic phase of this disease who do not have these resistant mutations. We investigated whether sensitive mutation analysis could identify other poor-risk subgroups. Analysis was performed by direct sequencing and sensitive mass spectrometry on 220 imatinib-resistant patients before they began nilotinib or dasatinib therapy. Patients with resistant mutations by either method (n = 45) were excluded because inferior response was known. Of the remaining 175 patients, 19% had multiple mutations by mass spectrometry versus 9% by sequencing. Compared with 0 or 1 mutation, the presence of multiple mutations was associated with lower rates of complete cytogenetic response (50% vs 21%, P = .003) and major molecular response (31% vs 6%, P = .005) and a higher rate of new resistant mutations (25% vs 56%, P = .0009). Sensitive mutation analysis identified a poor-risk subgroup (15.5% of all patients) with multiple mutations not identified by standard screening.
Publisher: Elsevier BV
Date: 08-2012
DOI: 10.1016/J.EXPHEM.2012.04.003
Abstract: Development of small molecule tyrosine kinase inhibitors for the treatment of chronic myeloid leukemia has been astonishingly successful however, their off-target effects have generated both challenges and opportunities for extending their clinical application. Dasatinib and imatinib are two of the most commonly used tyrosine kinase inhibitors and both have been shown to impact T-cell function. Due to this activity, their use as potential immune suppressants has been proposed. In this report, we investigated drug interactions with cyclosporine A in suppressing T-cell proliferation. Dasatinib and imatinib were titrated against varying concentrations of cyclosporine in the cultures and T-cell proliferation assessed by 5-6-carboxyfluorescein diacetate, succinimidyl ester dye dilution. These proliferation data were then used to determine the combination index to evaluate additive, synergistic, or antagonistic interactions between the drugs. This analysis uncovered a number of different drug interactions affecting T-cell proliferation. Cyclosporine had an additive or synergistic effect on T-cell proliferation when combined with dasatinib and imatinib for 3 of the 4 methods of stimulating T-cell proliferation. However, when T cells were stimulated with anti-CD3 and anti-CD28 antibodies, this interaction was found to be strongly antagonistic at low dasatinib concentrations. In contrast, this strong antagonism was not observed when imatinib was used in combination with cyclosporine A. This study suggests drug interactions affecting T cells may need to be carefully taken into account when using tyrosine kinase inhibitors. Furthermore, the technique to evaluate drug interactions is novel, and applicable to study any interaction affecting proliferation.
Publisher: Springer Science and Business Media LLC
Date: 03-02-2016
DOI: 10.1038/LEU.2016.5
Publisher: Springer Science and Business Media LLC
Date: 29-08-2022
DOI: 10.1038/S41375-022-01686-Y
Abstract: Therapy-related myeloid neoplasm (tMN) is considered a direct consequence of DNA damage in hematopoietic stem cells. Despite increasing recognition that altered stroma can also drive leukemogenesis, the functional biology of the tMN microenvironment remains unknown. We performed multiomic (transcriptome, DNA damage response, cytokine secretome and functional profiling) characterization of bone marrow stromal cells from tMN patients. Critically, we also compared (i) patients with myeloid neoplasm and another cancer but without cytotoxic exposure, (ii) typical primary myeloid neoplasm, and (iii) age-matched controls to decipher the microenvironmental changes induced by cytotoxics vs. neoplasia. Strikingly, tMN exhibited a profoundly senescent phenotype with induction of CDKN1A and β-Galactosidase, defective phenotype, and proliferation. Moreover, tMN stroma showed delayed DNA repair and defective adipogenesis. Despite their dormant state, tMN stromal cells were metabolically highly active with a switch toward glycolysis and secreted multiple pro-inflammatory cytokines indicative of a senescent-secretory phenotype that inhibited adipogenesis. Critically, senolytics not only eliminated dormant cells, but also restored adipogenesis. Finally, sequential patient s ling showed senescence phenotypes are induced within months of cytotoxic exposure, well prior to the onset of secondary cancer. Our data underscores a role of senescence in the pathogenesis of tMN and provide a valuable resource for future therapeutics.
Publisher: Springer Science and Business Media LLC
Date: 31-05-2009
DOI: 10.1038/NG.392
Publisher: Springer Science and Business Media LLC
Date: 19-12-2016
DOI: 10.1007/S40262-016-0494-0
Abstract: The aims of this study were to determine the effects of the CYP2C8*3 and *4 polymorphisms on imatinib metabolism and plasma imatinib concentrations in chronic myeloid leukaemia (CML) patients. We genotyped 210 CML patients from the TIDELII trial receiving imatinib 400-800 mg/day for CYP2C8*3 (rs11572080, rs10509681) and *4 (rs1058930). Steady-state trough total plasma N-desmethyl imatinib (major metabolite):imatinib concentration ratios (metabolic ratios) and trough total plasma imatinib concentrations were compared between genotypes (one-way ANOVA with Tukey post hoc). CYP2C8*3 (n = 34) and *4 (n = 15) carriers had significantly higher (P < 0.01) and lower (P 50% higher for CYP2C8*1/*4 than for CYP2C8*1/*1 and CYP2C8*3 carriers (2.18 ± 0.66 vs. 1.45 ± 0.74 [P < 0.05] and 1.36 ± 0.98 μg/mL [P < 0.05], respectively). CYP2C8 genotype significantly alters imatinib metabolism in patients through gain- and loss-of-function mechanisms.
Publisher: American Society of Clinical Oncology (ASCO)
Date: 09-2018
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.JMOLDX.2017.05.009
Abstract: Somatic mitochondrial DNA (mtDNA) mutations have been identified in many human cancers, including leukemia. To identify somatic mutations, it is necessary to have a control tissue from the same in idual for comparison. When patients with leukemia achieve remission, the remission peripheral blood may be a suitable and easily accessible control tissue, but this approach has not previously been applied to the study of mtDNA mutations. We have developed and validated a next-generation sequencing approach for the identification of leukemia-associated mtDNA mutations in 26 chronic myeloid leukemia patients at diagnosis using either nonhematopoietic or remission blood s les as the control. The entire mt genome was lified by long-range PCR and sequenced using Illumina technology. Variant caller software was used to detect mtDNA somatic mutations, and an empirically determined threshold of 2% was applied to minimize false-positive results because of sequencing errors. Mutations were called against both nonhematopoietic and remission controls: the overall concordance between the two approaches was 81% (73/90 mutations). Some discordant results were because of the presence of somatic mutations in remission s les, because of either minimal residual disease or nonleukemic hematopoietic clones. This method could be applied to study somatic mtDNA mutations in leukemia patients who achieve minimal residual disease, and in patients with nonhematopoietic cancers who have a matched uninvolved tissue available.
Publisher: Wiley
Date: 26-11-2010
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 14-02-2014
Publisher: Springer Science and Business Media LLC
Date: 26-01-2018
DOI: 10.1038/S41467-017-02633-7
Abstract: The interleukin-3 (IL-3) receptor is a cell-surface heterodimer that links the haemopoietic, vascular and immune systems and is overexpressed in acute and chronic myeloid leukaemia progenitor cells. It belongs to the type I cytokine receptor family in which the α-subunits consist of two fibronectin III-like domains that bind cytokine, and a third, evolutionarily unrelated and topologically conserved, N-terminal domain (NTD) with unknown function. Here we show by crystallography that, while the NTD of IL3Rα is highly mobile in the presence of IL-3, it becomes surprisingly rigid in the presence of IL-3 K116W. Mutagenesis, biochemical and functional studies show that the NTD of IL3Rα regulates IL-3 binding and signalling and reveal an unexpected role in preventing spontaneous receptor dimerisation. Our work identifies a dual role for the NTD in this cytokine receptor family, protecting against inappropriate signalling and dynamically regulating cytokine receptor binding and function.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 02-11-2018
Abstract: Pathological drug withdrawal syndrome is linked to accumulation of JAK2 phosphorylation in V617F myelofibrosis.
Publisher: American Society of Clinical Oncology (ASCO)
Date: 20-07-2009
Abstract: Patients with chronic myelogenous leukemia in accelerated phase (CML-AP) that is resistant or intolerant to imatinib have limited therapeutic options. Dasatinib, a potent inhibitor of BCR-ABL and SRC-family kinases, has efficacy in patients with CML-AP who have experienced treatment failure with imatinib. We now report follow-up data from the full patient cohort of 174 patients enrolled onto a phase II trial to provide a more complete assessment of the efficacy and safety of dasatinib in this population. Patients with imatinib-resistant (n = 161) or -intolerant (n = 13) CML-AP received dasatinib 70 mg orally twice daily. At a median follow-up of 14.1 months (treatment duration, 0.1 to 21.7 months), major and complete hematologic responses were attained by 64% and 45% of patients, respectively, and major and complete cytogenetic responses were achieved in 39% and 32% of patients, respectively. Responses were achieved irrespective of imatinib status (resistant or intolerant), prior stem-cell transplantation, or the presence of prior BCR-ABL mutation. The 12-month progression-free survival and overall survival rates were 66% and 82%, respectively. Dasatinib was generally well tolerated the most frequent nonhematologic severe treatment-related adverse event was diarrhea (52% grade 3 to 4, 8%). Cytopenias were common, including grade 3 to 4 neutropenia (76%) and thrombocytopenia (82%). Pleural effusion occurred in 27% of patients (grade 3 to 4, 5%). Dasatinib is effective in patients with CML-AP after imatinib treatment failure.
Publisher: American Society of Clinical Oncology (ASCO)
Date: 10-01-2017
Abstract: Immunologic surveillance of minimal residual disease in chronic myelogenous leukemia (CML) may be relevant for long-term control or cure of CML. Little is known about immune-modulatory effects of nilotinib in vivo, potentially predicting response to therapy. A prospective and comprehensive flow cytometry–based immunomonitoring program paralleled the ENEST1st clinical study, investigating 52 nilotinib-naïve patients with chronic-phase CML. Data were verified in independent validation cohorts. T cells of patients with CML at diagnosis expressed low l-selectin (CD62L) levels, which was not a result of proportional aberrations of T-cell subsets. Low numbers of CD62L-expressing CD4 + and CD8 + T cells correlated with higher Sokal score, increased spleen size, and high leukocyte and peripheral-blood blast counts. At month 6 during nilotinib therapy, CD62L expression returned to levels of healthy in iduals. The level of CD62L loss on T cells directly correlated with the extent of soluble CD62L (sCD62L) elevation. In parallel, the proteolytic activity of tumor necrosis factor α–converting enzyme (TACE ADAM17, CD156b), the metalloproteinase shedding CD62L, was increased at diagnosis and significantly decreased during nilotinib treatment. High CD62L + expression on both CD4 + and CD8 + T cells and, vice versa, low sCD62L levels at CML diagnosis were linked to superior molecular responses. These findings were corroborated in independent validation cohorts. We demonstrate the prognostic impact of CD62L shedding from T cells and increased sCD62L plasma levels at CML diagnosis on molecular response to tyrosine kinase inhibitor therapy in early chronic-phase CML. Functionally, decreased CD62L may be a consequence of increased TACE-mediated CD62L cleavage and potentially impairs immune-cell function. Larger prospective studies are ongoing to confirm the prognostic relevance of this finding.
Publisher: Elsevier BV
Date: 05-2016
Publisher: Wiley
Date: 30-07-2020
DOI: 10.1111/BJH.17002
Publisher: Oxford University Press (OUP)
Date: 09-2008
DOI: 10.1373/CLINCHEM.2008.105916
Abstract: Background: Real-time quantitative reverse transcription PCR (RQ-PCR) assay for BCR-ABL is used to monitor treatment response in chronic myeloid leukemia (CML). BCR-ABL transcript levels decline over several years of imatinib treatment, and increasing numbers of patients have BCR-ABL transcripts at or below the limit of detection. More sensitive PCR methods are required to assess whether these patients have a long-term continuing decline in residual disease. Methods: We used random pentadecamer (R15) primers for reverse transcription in RQ-PCR and compared the results with our established method that uses random hexamers. An increase in assay sensitivity would be detected as an increase in the number of BCR-ABL transcripts. Results: BCR-ABL transcripts increased by 86% with R15 primers. We used R15 primers to retest 19 s les from selected CML patients who had no BCR-ABL transcripts recently detectable with hexamer primers and detected BCR-ABL transcripts in 68% of the s les. Use of R15 primers showed variable increases in the transcripts for control genes BCR (breakpoint cluster region), ABL1 (c-abl oncogene 1, receptor tyrosine kinase), and GUSB (glucuronidase, beta), depending on the gene examined. The reported BCR-ABL/control gene ratio was affected, and the estimated detection limit of the assay, which was based on increased control gene copy number, was different for each control gene. Conclusions: This simple modification to the reverse transcription methodology improved the detection limit of the RQ-PCR assay for BCR-ABL transcripts. In the field of CML, these results have important implications for defining the detection limit of an assay when the BCR-ABL transcript is undetectable. Random pentadecamer primers may also be useful in other reverse transcription PCR assays for which the abundance of the target RNA is low.
Publisher: Impact Journals, LLC
Date: 05-10-2018
Publisher: American Society of Hematology
Date: 02-05-2013
DOI: 10.1182/BLOOD-2012-04-423418
Abstract: Frontline nilotinib led to fewer, less erse BCR-ABL mutations than imatinib in patients with chronic myeloid leukemia in chronic phase. Rates of progression to accelerated phase/blast crisis were lower with nilotinib than imatinib in patients with emergent BCR-ABL mutations.
Publisher: Springer Science and Business Media LLC
Date: 04-02-2010
DOI: 10.1038/LEU.2009.299
Abstract: In chronic myeloid leukemia (CML) cell lines, brief exposure to pharmacologically relevant dasatinib concentrations results in apoptosis. In this study, we assess the impact of intensity and duration of Bcr-Abl kinase inhibition on primary CD34(+) progenitors of chronic phase CML patients. As CML cells exposed to dasatinib in vivo are in a cytokine-rich environment, we also assessed the effect of cytokines (six growth factors cocktail or granulocyte-macrophage colony-stimulating factor (CSF) or granulocyte-CSF) in combination with dasatinib. In the presence of cytokines, short-term intense Bcr-Abl kinase inhibition (>or=90% p-Crkl inhibition) with 100 nM dasatinib did not reduce CD34(+) colony-forming cells (CFCs). In contrast, without cytokines, short-term exposure to dasatinib reduced CML-CD34(+) CFCs by 70-80%. When cytokines were added immediately after short-term exposure to dasatinib, CML-CD34(+) cells remained viable, suggesting that oncogene dependence of these cells can be overcome by concomitant or subsequent exposure to cytokines. Additional inhibition of Janus tyrosine kinase (Jak) activity re-established the sensitivity of CML progenitors to intense Bcr-Abl kinase inhibition despite the presence of cytokines. These findings support the contention that therapeutic strategies combining intense Bcr-Abl kinase inhibition and blockade of cytokine signaling pathways can be effective for eradication of CML progenitors.
Publisher: Springer Science and Business Media LLC
Date: 29-06-2015
DOI: 10.1038/LEU.2015.168
Publisher: Informa UK Limited
Date: 12-11-2013
Publisher: Springer Science and Business Media LLC
Date: 30-03-2011
DOI: 10.1007/S11899-011-0087-9
Abstract: As of 2011, the choice of tyrosine kinase inhibitor (TKI) for the patient with newly diagnosed chronic-phase chronic myelogenous leukemia (CP-CML) is no longer limited to imatinib but can be expanded to include nilotinib and dasatinib. Since 2000, imatinib has demonstrated remarkable efficacy in the majority of chronic-phase patients. Nilotinib and dasatinib, both more potent TKIs, are likely to produce quicker and deeper molecular responses, but there are no established criteria for choosing the best inhibitor for each patient. We now need to establish clearly defined recommendations to address this new stage, in which in idualized therapy in the front-line should become a reality. Likely to be paramount in this setting are assays that directly assess the efficacy of the protein-drug and drug-transporter interactions, taking into account factors intrinsic to the patient, factors related to disease stage, and the amount of drug freely available in the plasma.
Publisher: Informa UK Limited
Date: 23-04-2012
Publisher: American Society of Hematology
Date: 04-03-2021
Abstract: With treatment-free remission (TFR) rapidly becoming the ultimate goal of therapy in chronic myeloid leukemia (CML), there is a need to develop strategies to maximize sustained TFR by improving our understanding of its key determinants. Chronic-phase CML patients attempting TFR were evaluated to identify the impact of multiple variables on the probability of sustained TFR. Early molecular response dynamics were included as a predictive variable, assessed by calculating the patient-specific halving time of BCR-ABL1 after commencing tyrosine kinase inhibitor (TKI) therapy. Overall, 115 patients attempted TFR and had ≥12 months of follow-up. The probability of sustained TFR, defined as remaining in major molecular response off TKI therapy for 12 months, was 55%. The time taken for the BCR-ABL1 value to halve was the strongest independent predictor of sustained TFR: 80% in patients with a halving time of & .35 days (first quartile) compared with only 4% if the halving time was & .85 days (last quartile) (P & .001). The e14a2 BCR-ABL1 transcript type and duration of TKI exposure before attempting TFR were also independent predictors of sustained TFR. However, the BCR-ABL1 value measured at 3 months of TKI was not an independent predictor of sustained TFR. A more rapid initial BCR-ABL1 decline after commencing TKI also correlated with an increased likelihood of achieving TFR eligibility. The association between sustained TFR and the time taken for BCR-ABL1 to halve after commencing TKI was validated using an independent dataset. These data support the critical importance of the initial kinetics of BCR-ABL1 decline for long-term outcomes.
Publisher: American Society of Hematology
Date: 29-09-2011
DOI: 10.1182/BLOOD-2011-03-341073
Abstract: We prove that the SH2-containing tyrosine phosphatase 1 (SHP-1) plays a prominent role as resistance determinant of imatinib (IMA) treatment response in chronic myelogenous leukemia cell lines (sensitive/KCL22-S and resistant/KCL22-R). Indeed, SHP-1 expression is significantly lower in resistant than in sensitive cell line, in which coimmunoprecipitation analysis shows the interaction between SHP-1 and a second tyrosine phosphatase SHP-2, a positive regulator of RAS/MAPK pathway. In KCL22-R SHP-1 ectopic expression restores both SHP-1/SHP-2 interaction and IMA responsiveness it also decreases SHP-2 activity after IMA treatment. Consistently, SHP-2 knocking-down in KCL22-R reduces either STAT3 activation or cell viability after IMA exposure. Therefore, our data suggest that SHP-1 plays an important role in BCR-ABL–independent IMA resistance modulating the activation signals that SHP-2 receives from both BCR/ABL and membrane receptor tyrosine kinases. The role of SHP-1 as a determinant of IMA sensitivity has been further confirmed in 60 consecutive untreated patients with chronic myelogenous leukemia, whose SHP-1 mRNA levels were significantly lower in case of IMA treatment failure (P .0001). In conclusion, we suggest that SHP-1 could be a new biologic indicator at baseline of IMA sensitivity in patients with chronic myelogenous leukemia.
Publisher: American Society of Hematology
Date: 25-10-0012
DOI: 10.1182/BLOOD-2015-07-655589
Abstract: KIR2DL5B is associated with poor molecular response and transformation-free survival in CML patients enrolled to the TIDEL-II study. KIR genotyping would select out high risk CML patients at baseline and allow better targeting of novel interventions.
Publisher: American Society of Clinical Oncology (ASCO)
Date: 06-2010
Abstract: Organic cation transporter-1 (OCT-1) activity (OA), a measure of the OCT-1–mediated influx of imatinib into CML mononuclear cells (MNCs), is predictive of major molecular response (MMR) at 12 and 24 months in patients with untreated CML. We now report the impact of OA on loss of response, disease transformation, and survival after 5 years of imatinib. OA is defined as the difference in intracellular concentration of carbon-14–imatinib with and without OCT-1 inhibition. OA was measured in blood from 56 patients with untreated chronic-phase CML. More patients who had high OA (ie, median OA value) achieved MMR by 60 months compared with patients who had low OA (89% v 55% P = .007). A low OA was associated with a significantly lower overall survival (87% v 96% P = .028) and event-free survival (EFS 48% v 74% P = .03) as well as a higher kinase domain mutation rate (21% v 4% P = .047). These differences were highly significant in patients who averaged less than 600 mg/d of imatinib in the first 12 months but were not significant in patients averaging ≥ 600 mg/d. Patients with very low OA (ie, quartile 1) were the only group who developed leukemic transformation (21% in quartile 1 v 0% in all other quartiles P = .002). Measurement of OA pretherapy is a predictor for the long-term risk of resistance and transformation in patients with imatinib-treated CML. Early dose-intensity may reduce the negative prognostic impact of low OA. We propose that OA could be used to in idualize dosage strategies for patients with CML to maximize molecular response and optimize long-term outcome.
Publisher: Massachusetts Medical Society
Date: 17-06-2010
Publisher: American Society of Hematology
Date: 02-03-2017
DOI: 10.1182/BLOOD-2016-10-745992
Abstract: Increased immune suppressors and PD-1 abrogates effector responses in CML patients at diagnosis. Enhanced net effector immune responses and decreased PD-1 and immune suppressors may promote sustained deep molecular response in CML.
Publisher: Public Library of Science (PLoS)
Date: 31-01-2018
Publisher: Springer Science and Business Media LLC
Date: 06-11-2014
DOI: 10.1038/LEU.2013.329
Publisher: American Society of Hematology
Date: 11-08-2011
DOI: 10.1182/BLOOD-2011-02-339267
Abstract: Treatment of chronic myeloid leukemia (CML) with the tyrosine kinase inhibitors (TKIs) imatinib mesylate and nilotinib represents a successful application of molecularly targeted anticancer therapy. However, the effect of TKIs on leukemic stem cells remains incompletely understood. On the basis of a statistical modeling approach that used the 10-year imatinib mesylate treatment response of patients with CML and a patient cohort receiving first-line nilotinib therapy, we found that successful long-term therapy results in a triphasic exponential decline of BCR-ABL1 transcripts in many patients. Within our framework, the first slope of −0.052 ± 0.018 (imatinib mesylate) and −0.042 ± 0.015 (nilotinib) per day represents the turnover rate of leukemic differentiated cells, whereas the second slope of −0.0057 ± 0.0038 (imatinib mesylate) and −0.0019 ± 0.0013 (nilotinib) per day represents the turnover rate of leukemic progenitor cells. The third slope allows an inference of the behavior of immature leukemic cells, potentially stem cells. This third slope is negative in most patients, positive in others, and not observable in some patients. This variability in response may be because of insufficient follow-up, missing data, disease heterogeneity, inconsistent compliance to drug, or acquired resistance. Our approach suggests that long-term TKI therapy may reduce the abundance of leukemic stem cells in some patients.
Publisher: Springer Science and Business Media LLC
Date: 02-09-2010
DOI: 10.1038/LEU.2010.188
Publisher: Springer Science and Business Media LLC
Date: 28-05-2018
Publisher: Springer Science and Business Media LLC
Date: 02-09-2010
DOI: 10.1038/LEU.2010.185
Abstract: Around 40-50% of patients with chronic myeloid leukemia (CML) who achieve a stable complete molecular response (CMR undetectable breakpoint cluster region-Abelson leukemia gene human homolog 1 (BCR-ABL1) mRNA) on imatinib can stop therapy and remain in CMR, at least for several years. This raises the possibility that imatinib therapy may not need to be continued indefinitely in some CML patients. Two possible explanations for this observation are (1) CML has been eradicated or (2) residual leukemic cells fail to proliferate despite the absence of ongoing kinase inhibition. We used a highly sensitive patient-specific nested quantitative PCR to look for evidence of genomic BCR-ABL1 DNA in patients who sustained CMR after stopping imatinib therapy. Seven of eight patients who sustained CMR off therapy had BCR-ABL1 DNA detected at least once after stopping imatinib, but none has relapsed (follow-up 12-41 months). BCR-ABL1 DNA levels increased in all of the 10 patients who lost CMR soon after imatinib cessation, whereas serial testing of patients in sustained CMR showed a stable level of BCR-ABL1 DNA. This more sensitive assay for BCR-ABL1 provides evidence that even patients who maintain a CMR after stopping imatinib may harbor residual leukemia. A search for intrinsic or extrinsic (for ex le, immunological) causes for this drug-free leukemic suppression is now indicated.
Publisher: American College of Physicians
Date: 02-10-2018
DOI: 10.7326/L18-0431
Publisher: American Society of Hematology
Date: 30-08-2018
DOI: 10.1182/BLOOD-2018-02-832253
Abstract: Next-generation sequencing revealed variants in cancer-associated genes at diagnosis of CML more frequently in patients with poor outcomes. All patients at BC had mutated cancer genes, including fusions, that predated BCR-ABL1 kinase domain mutations in a majority.
Publisher: Springer Science and Business Media LLC
Date: 09-07-2015
DOI: 10.1038/LEU.2015.170
Abstract: Imatinib is a highly effective therapy for chronic phase-chronic myeloid leukaemia (CP-CML) patients however, responses to frontline imatinib are variable. The human organic cation transporter 1 (OCT1 SLC22A1) has been reported to be the main influx transporter involved in imatinib uptake into CML cells. Furthermore, variation in the efficiency of imatinib influx via OCT1 has been demonstrated to result in the inter-patient variation observed in primary response to imatinib. Although studies have questioned the role of OCT1 in imatinib influx, these have been largely performed in non-clinical settings. Measuring both OCT1 mRNA levels and the functional activity of OCT1 in primary leukaemic cells has been demonstrated to predict molecular response and outcome in imatinib-treated CP-CML patients in several independent studies. Here, the role of OCT1 and OCT1 genetic variants in imatinib uptake and response prediction is summarised and data generated from model systems assessing the role of OCT1 in imatinib transport is discussed.
Publisher: Springer Science and Business Media LLC
Date: 07-02-2017
Publisher: Wiley
Date: 30-03-2020
DOI: 10.1111/BJH.16599
Publisher: Springer Science and Business Media LLC
Date: 02-09-2015
DOI: 10.1038/LEU.2014.256
Publisher: American Society of Hematology
Date: 27-01-2011
DOI: 10.1182/BLOOD-2010-03-277152
Abstract: Nilotinib is a potent selective inhibitor of the BCR-ABL tyrosine kinase approved for use in patients with newly diagnosed chronic myeloid leukemia in chronic phase (CML-CP), and in CML-CP and CML-accelerated phase after imatinib failure. Nilotinib (400 mg twice daily) was approved on the basis of the initial results of this phase 2 open-label study. The primary study endpoint was the proportion of patients achieving major cytogenetic response (CyR). All patients were followed for ≥ 24 months or discontinued early. Of 321 patients, 124 (39%) continue on nilotinib treatment. Overall, 59% of patients achieved major CyR this was complete CyR (CCyR) in 44%. Of patients achieving CCyR, 56% achieved major molecular response. CyRs were durable, with 84% of patients who achieved CCyR maintaining response at 24 months. The overall survival at 24 months was 87%. Adverse events were mostly mild to moderate, generally transient, and easily managed. This study indicates that nilotinib is effective, with a manageable safety profile, and can provide favorable long-term benefits for patients with CML-CP after imatinib failure. This trial was registered at www.clinicaltrials.gov as #NCT00109707.
Publisher: Informa UK Limited
Date: 04-08-2014
DOI: 10.3109/10428194.2014.925547
Abstract: We report long-term results in 40 patients with Philadlephia chromosome-positive (Ph+) acute leukemia who received an imatinib monotherapy window to evaluate in vivo effects on BCR-ABL signaling prior to induction chemotherapy. The first 25 patients (cohort 1) received the LALA-94 protocol without further imatinib (newly diagnosed Ph+ acute lymphoblastic leukemia [ALL]) or induction chemotherapy followed by single-agent imatinib. Subsequent patients (cohort 2) continued imatinib concurrently with either LALA-94 (newly diagnosed Ph + ALL) or other intensive chemotherapy regimens. Cohort 2 had a complete response (CR) rate of 93% and 5-year survival of 69%. For newly diagnosed Ph+ ALL, survival was superior in cohort 2 compared with cohort 1. Toxicity was similar to that expected for chemotherapy alone. Among 10 evaluable patients, rapid loss of phospho-CRKL occurred during the imatinib window in seven patients (all achieved CR) and incomplete inhibition in three patients (none with CR). In summary, a pharmacodynamic window design permitted biomarker assessment of BCR-ABL targeting without compromising clinical outcomes.
Publisher: American Society of Hematology
Date: 28-01-2010
DOI: 10.1182/BLOOD-2009-08-237404
Abstract: Imatinib mesylate is a rationally designed tyrosine kinase inhibitor that has revolutionized the treatment of chronic myeloid leukemia and gastrointestinal stromal tumors. Although the efficacy and tolerability of imatinib are a vast improvement over conventional chemotherapies, the drug exhibits off-target effects. An unanticipated side effect of imatinib therapy is hypophosphatemia and hypocalcemia, which in part has been attributed to drug-mediated changes to renal and gastrointestinal handling of phosphate and calcium. However, emerging data suggest that imatinib also targets cells of the skeleton, stimulating the retention and sequestration of calcium and phosphate to bone, leading to decreased circulating levels of these minerals. The aim of this review is to highlight our current understanding of the mechanisms surrounding the effects of imatinib on the skeleton. In particular, it examines recent studies suggesting that imatinib has direct effects on bone-resorbing osteoclasts and bone-forming osteoblasts through inhibition of c-fms, c-kit, carbonic anhydrase II, and the platelet-derived growth factor receptor. The potential application of imatinib in the treatment of cancer-induced osteolysis will also be discussed.
Publisher: Public Library of Science (PLoS)
Date: 19-03-2013
Publisher: The Endocrine Society
Date: 2013
DOI: 10.1210/JC.2012-2426
Abstract: Imatinib is a tyrosine kinase inhibitor that has been successfully used to treat Philadelphia chromosome-positive chronic myeloid leukemia (CML) and Kit+ gastrointestinal stromal tumors. We have previously shown that imatinib therapy is associated with an increase in trabecular bone volume. In the present study, we performed a prospective analysis of bone indices in imatinib-treated CML patients to determine the mechanism responsible for this altered bone remodeling. This study assessed the effects of high-dose (600 mg/d) imatinib on bone parameters in newly diagnosed chronic-phase Philadelphia chromosome-positive CML patients (n = 11) enrolled in the TIDEL II study. At baseline and after 6, 12, and 24 months of treatment, serum markers of bone remodeling were quantitated, dual-energy x-ray absorptiometry analysis of bone mineral density (BMD) was carried out, and a bone biopsy was collected for histological and micro-computed tomography analysis. Our studies show that the increase in trabecular bone volume and trabecular thickness after imatinib treatment was associated with a significant decrease in osteoclast numbers, accompanied by a significant decrease in serum levels of a marker of osteoclast activity. In contrast, osteoblast numbers were not altered by up to 24 months of imatinib treatment. Notably, we also found that imatinib caused a site-specific decrease in BMD at the femoral neck. These data suggest that imatinib therapy dysregulates bone remodeling, causing a generalized decrease in osteoclast number and activity that is not counterbalanced by a decrease in osteoblast activity, leading to increased trabecular bone volume. Further long-term investigations are required to determine the causes and consequences of the site-specific decrease in BMD at the femoral neck.
Publisher: BMJ
Date: 02-02-2016
DOI: 10.1136/JCLINPATH-2015-203538
Abstract: RT-qPCR is used to quantify minimal residual disease (MRD) in chronic myeloid leukaemia (CML) in order to make decisions on treatment, but its results depend on the level of BCR-ABL1 expression as well as leukaemic cell number. The aims of the study were to quantify inter-in idual differences in expression level, to determine the relationship between expression level and response to treatment, and to investigate the effect of expression level on interpretation of the RT-qPCR result. BCR-ABL1 expression was studied in 248 s les from 65 patients with CML by determining the difference between MRD quantified by RT-qPCR and DNA-qPCR. The results were analysed statistically and by simple indicative modelling. Inter-in idual levels of expression approximated a normal distribution with an SD of 0.36 log. Expression at diagnosis correlated with expression during treatment. Response to treatment, as measured by the number of leukaemic cells after 3, 6 or 12 months of treatment, was not related to the level of expression. Indicative modelling suggested that interpretation of RT-qPCR results in relation to treatment guidelines could be affected by variation in expression when MRD was around 10% at 3 months and by both expression variation and Poisson variation when MRD was around or below the limit of detection of RT-qPCR. Variation between in iduals in expression of BCR-ABL1 can materially affect interpretation of the RT-qPCR when this test is used to make decisions on treatment.
Publisher: American Society of Hematology
Date: 2009
DOI: 10.1182/ASHEDUCATION-2009.1.477
Abstract: The remarkable progress made in the treatment of chronic myeloid leukemia (CML) over the past decade has been accompanied by steady improvements in our capacity to accurately and sensitively monitor response to therapy. After the initial target of therapy, complete cytogenetic response (CCR), is achieved, peripheral blood BCR-ABL transcript levels measured by real-time quantitative reverse transcriptase PCR (RQ-PCR) define the subsequent response targets, major and complete molecular response (MMR and CMR). The majority of patients on first-line imatinib therapy achieve a “safe haven” defined as a confirmed MMR, but 20% to 30% stop imatinib due to intolerance and/or resistance. Many imatinib-resistant patients can be effectively treated with second generation tyrosine kinase inhibitors (TKIs), but the actual drug selected should be based on the resistance profile of each inhibitor, in addition to issues of tolerance and disease phase. The main purpose of monitoring response with cytogenetics and RQ-PCR is to identify patients likely to achieve better long-term outcome if they are switched early to second-line therapy, either another TKI or an allograft. Mutation screening is most valuable in cases of loss of response to imatinib or a second-line TKI, but there are other settings where a high yield of mutations may justify regular mutation screening.
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 05-07-2018
Publisher: Elsevier BV
Date: 12-2009
DOI: 10.1016/J.EXPHEM.2009.09.007
Abstract: Dasatinib (SPRYCEL, BMS-354825) is a small molecule Src/Abl tyrosine kinase inhibitor approved for the treatment of chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia. However, kinases inhibited by dasatinib are also involved in the induction and regulation of innate immunity. The purpose of this study was to evaluate the effect of dasatinib on cytokine secretion in response to toll-like receptor (TLR) stimulation. Dasatinib-treated mice were administered intraperitoneally with lipopolysaccharide (LPS) and serum cytokine (tumor necrosis factor-alpha [TNF-alpha], interleukin [IL]-10, and IL-6) levels and neutrophil accumulation in the lungs were analyzed. Cytokine secretions (TNF-alpha and IL-6) from TLR3-, TLR4-, and TLR9-stimulated RAW264.7, as well as TLR4- and TLR9-stimulated bone marrow-derived macrophages (BMDM) were also evaluated. Dasatinib-treated mice had reduced serum levels of TNF-alpha in response to LPS administration however, other inflammatory hallmarks of systemic LPS administration, such as secretion of IL-6 and accumulation of neutrophils in the lung, were unaffected. In contrast to the reduced TNF-alpha levels, dasatinib treatment increased serum levels of IL-10 following LPS administration. The production of TNF-alpha was also impaired in vitro in response to TLR3, TLR4, and TLR9 stimulation of the mouse macrophage cell line RAW264.7, as well as TLR4 and TLR9 stimulation of BMDM IL-6 production was also impaired in dasatinib-treated BMDM. These findings further support the ability of dasatinib to modulate the host immune response and highlights scope for off-target applications of dasatinib for the control of TNF-alpha-mediated inflammatory disorders.
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 09-08-2018
Publisher: American Society of Hematology
Date: 09-05-2013
DOI: 10.1182/BLOOD-2012-10-462291
Abstract: Independent predictors of stable, undetectable BCR-ABL1 during first-line imatinib therapy were female sex and the BCR-ABL1 value at 3 months. Time to achieve an MMR influenced time to stable, undetectable BCR-ABL1, suggesting slower dynamics of BCR-ABL1 decline with delayed MMR.
Publisher: Springer Science and Business Media LLC
Date: 06-11-2012
DOI: 10.1038/LEU.2012.305
Publisher: Springer Science and Business Media LLC
Date: 11-02-2010
DOI: 10.1038/LEU.2010.7
Publisher: Springer Science and Business Media LLC
Date: 10-12-2010
DOI: 10.1038/LEU.2009.242
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.LEUKRES.2018.02.013
Abstract: Some patients receiving a tyrosine kinase inhibitor (TKI) for the first-line treatment of chronic phase chronic myeloid leukemia (CML-CP) experience intolerable adverse events. Management strategies include dose adjustments, interrupting or discontinuing therapy, or switching to an alternative TKI. This multicenter, single-arm, Phase IIIb study included CML-CP patients intolerant of, but responsive to, first-line treatment with imatinib or dasatinib. All patients were switched to nilotinib 300 mg bid for up to 24 months. The primary endpoint was achievement of MR4.5 (BCR-ABL transcript level of ≤0.0032% on the International Scale) by 24 months. Twenty patients were enrolled in the study (16 imatinib-intolerant, 4 dasatinib-intolerant) which was halted early because of low recruitment. After the switch to nilotinib 300 mg bid, MR4.5 at any time point up to month 24 was achieved in 10 of 20 patients (50%) in the full analysis set. Of the non-hematological adverse events associated with intolerance to prior imatinib or dasatinib, 74% resolved within 12 weeks of switching to nilotinib 300 mg bid. Nilotinib 300 mg bid shows minimal cross intolerance in patients with CML-CP who have prior toxicities to other TKIs and can lead to deep molecular responses.
Publisher: American Society of Clinical Oncology (ASCO)
Date: 04-2012
Publisher: American Society of Clinical Oncology (ASCO)
Date: 10-11-2011
Abstract: BCR-ABL1 mutation analysis is recommended to facilitate selection of appropriate therapy for patients with chronic myeloid leukemia after treatment with imatinib has failed, since some frequently occurring mutations confer clinical resistance to nilotinib and/or dasatinib. However, mutations could be present below the detection limit of conventional direct sequencing. We developed a sensitive, multiplexed mass spectrometry assay (detection limit, 0.05% to 0.5%) to determine the impact of low-level mutations after imatinib treatment has failed. Mutation status was assessed in 220 patients treated with nilotinib or dasatinib after they experienced resistance to imatinib. Mutations were detected by sequencing in 128 patients before commencing nilotinib or dasatinib therapy (switchover). In 64 patients, 132 additional low-level mutations were detected by mass spectrometry alone (50 of 132 mutations were resistant to nilotinib and/or dasatinib). When patients received the inhibitor for which the mutation confers resistance, 84% of the low-level resistant mutations rapidly became dominant clones detectable by sequencing, including 11 of 12 T315I mutations. Subsequent complete cytogenetic response rates were lower for patients with resistant mutations at switchover detected by sequencing (0%) or mass spectrometry alone (16%) compared with patients with other mutations or no mutations (41% and 49%, respectively P .001). Failure-free survival among the 100 patients with chronic phase chronic myeloid leukemia when resistant mutations were detected at switchover by sequencing or mass spectrometry alone was 0% and 0% compared with 51% and 45% for patients with other mutations or no mutations (P = .003). Detection of low-level mutations after imatinib resistance offers critical information to guide subsequent therapy selection. If an inappropriate kinase inhibitor is selected, there is a high risk of treatment failure with clonal expansion of the resistant mutant.
Publisher: American Society of Hematology
Date: 03-07-2014
Publisher: Informa UK Limited
Date: 18-01-2012
DOI: 10.3109/08977194.2011.649919
Abstract: Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pluripotent cytokine produced by many cells in the body, which regulates normal and malignant hemopoiesis as well as innate and adaptive immunity. GM-CSF assembles and activates its heterodimeric receptor complex on the surface of myeloid cells, initiating multiple signaling pathways that control key functions such as cell survival, cell proliferation, and functional activation. Understanding the molecular composition of these pathways, the interaction of the various components as well as the kinetics and dose-dependent mechanics of receptor activation provides valuable insights into the function of GM-CSF as well as the related cytokines, interleukin-3 and interleukin-5. This knowledge provides opportunities for the development of new therapies to block the action of these cytokines in hematological malignancy and chronic inflammation.
Publisher: Wiley
Date: 07-04-2017
DOI: 10.1002/CNCR.30558
Publisher: Springer Science and Business Media LLC
Date: 30-12-2011
Publisher: Springer Science and Business Media LLC
Date: 16-04-2013
DOI: 10.1038/LEU.2013.116
Publisher: Elsevier BV
Date: 03-2015
DOI: 10.1016/J.JMOLDX.2014.10.002
Abstract: The BCR-ABL1 sequence has advantages over the BCR-ABL1 transcript as a molecular marker in chronic myeloid leukemia and has been used in research studies. We developed a DNA real-time quantitative PCR (qPCR) method for quantification of BCR-ABL1 sequences, which is also potentially suitable for routine use. The BCR-ABL1 breakpoint was sequenced after isolation by nested short-range PCR of DNA from blood, marrow, and cells on slides, obtained either at diagnosis or during treatment, or from artificial mixtures. PCR primers were chosen from a library of presynthesized and pretested BCR (n = 19) and ABL1 (n = 568) primers. BCR-ABL1 sequences were quantified relative to BCR sequences in 521 assays on 266 s les from 92 patients. For minimal residual disease detectable by DNA qPCR and RT-qPCR, DNA qPCR gave similar minimal residual disease results as RT-qPCR but had better precision at low minimal residual disease levels. The limit of detection of DNA qPCR depended on the amount of DNA assayed, being 10(-5.8) when 5 μg was assayed and 10(-7.0) when 80 μg was assayed. DNA qPCR may be useful and practical for monitoring the increasing number of patients with minimal residual disease around or below the limit of detection of RT-qPCR as the assay itself is simple and the up-front costs will be amortized if sequential assays are performed.
Publisher: American Society of Hematology
Date: 14-10-2010
DOI: 10.1182/BLOOD-2010-01-267013
Abstract: The functional activity of the organic cation transporter 1 (OCT-1) protein in chronic myeloid leukemia (CML) mononuclear cells (MNCs) is highly predictive of molecular response in imatinib treated patients. Here we investigate whether the MNC OCT-1 activity (OA) provides a surrogate indicator of effective targeting of the more immature CD34+ cells. While confirming our previous findings that high MNC OA is significantly associated with the achievement of major molecular response (MMR P = .017), the present studies found no relationship between high CD34+ OA and the achievement of MMR. Furthermore, no correlation was found between the MNC OA and the CD34+ OA in matched CML s les. These results suggest that the predictive value of the MNC OA may primarily reflect the effective targeting and subsequent reduction of mature CML cells. Therefore kinase inhibition in these mature cells, and not the CD34+ cells, may be the key determinant of response in CML.
Publisher: Wiley
Date: 23-04-2014
DOI: 10.1111/BJH.12892
Abstract: Treatment-free remission (TFR) has recently emerged as a goal of treatment in chronic myeloid leukaemia (CML). Molecular remission is sustained in around 30% of imatinib-treated patients who stop treatment after ≥2 years with undetectable minimal residual disease (UMRD) by conventional real-time reverse transcription polymerase chain reaction. An additional 20-30% of patients will lose UMRD, but remain in stable major molecular remission off treatment. Most patients with molecular recurrence have a significant increase in BCR-ABL1 within the first 6 months off treatment, but there are also rare late relapses. As re-treatment with imatinib restores control, a trial of TFR is safe so long as careful molecular monitoring is provided to enable prompt re-treatment. The minimum eligibility criteria for a trial of TFR are not yet defined, but the available data support a MRD level of around a molecular response of 4.5 log for at least 2 years. Factors associated with a higher probability of TFR include low risk Sokal score, prior interferon treatment, longer total duration of imatinib treatment and higher numbers of natural killer cells at the time of imatinib discontinuation. Preliminary data suggest that the rate of TFR in patients treated with more potent tyrosine kinase inhibitors will probably be higher. The biology that underlies TFR is an area of active investigation.
Publisher: Wiley
Date: 19-08-2013
DOI: 10.1111/BJH.12532
Publisher: Springer Science and Business Media LLC
Date: 12-05-2014
DOI: 10.1038/LEU.2014.156
Abstract: Kinase inhibitors block proliferative signals in BCR-ABL1+ leukemic cells, but their capacity to induce apoptosis is poorly understood. Initial studies suggested that very brief exposure to kinase inhibitors was sufficient to induce apoptosis in chronic myeloid leukemia (CML) cells. However, flaws in this experimental model have subsequently been identified, leading to the conclusion that apoptosis only occurs with sustained low-level kinase inhibition. Thus, the minimum duration of complete kinase inhibition required to commit CML cells to death is unknown. Here we confirm that <1 h is insufficient to induce significant commitment to death in BCR-ABL1+ cell lines and in primary CD34+ progenitor cells, and establish that commitment to cell death only occurs if kinase inhibition is maintained for 4 h or more. Remarkably, signal transducer and activator of transcription 5 (STAT5) inhibition in combination with transient (<1 h) tyrosine kinase inhibitor (TKI) exposure proved lethal for CML progenitors, despite the reactivation of Bcr-Abl after 1 h. JAK kinase inhibition did not induce cell death in combination with transient TKI exposure. Thus, STAT5 appears to be a critical determinant of the time-dependent sensitivity of CML progenitor cells to TKI treatment in a Bcr-Abl-dependent, but JAK-independent, manner. We conclude that combining kinase inhibition with STAT5 inhibition represents a promising therapeutic approach in BCR-ABL1+ leukemias.
Publisher: Springer Science and Business Media LLC
Date: 02-2011
DOI: 10.1038/LEU.2010.250
Publisher: Elsevier BV
Date: 03-2009
Publisher: Springer Science and Business Media LLC
Date: 20-11-2009
DOI: 10.1038/LEU.2008.330
Publisher: Informa UK Limited
Date: 21-08-2013
DOI: 10.3109/10428194.2012.715345
Abstract: Imatinib and nilotinib interact with ABCB1 and ABCG2. However, whether they are substrates or inhibitors is a source of conjecture. Here, in vitro, Bcr-Abl kinase inhibition was used to elucidate the impact of ABCB1/ABCG2 overexpression on imatinib and nilotinib transport. High levels of ABCB1 protein in K562-Dox cells resulted in a significantly increased 50% inhibitory concentration (IC(50)) compared with parental K562 cells for imatinib (IC(50)(IM) 9 µM to 19 µM, p = 0.002) and nilotinib (IC(50)(NIL) 345 nM to 620 nM, p = 0.013). This difference was abrogated by ABCB1 inhibitors. However, overexpression of ABCG2 did not significantly increase IC(50)(IM) or IC(50)(NIL) or significantly decrease IC(50) upon ABCG2 inhibition. Inhibition of ABCB1 but not ABCG2 resulted in a substantial increase in intracellular nilotinib when used at 150 nM but no increase when used at 2 µM. Imatinib and nilotinib appear to be transported by ABCB1 but do not interact strongly with ABCG2. Furthermore, ABCB1 efflux of nilotinib may be concentration-dependent with transport occurring at clinically relevant concentrations.
Publisher: Public Library of Science (PLoS)
Date: 18-08-2016
Publisher: Massachusetts Medical Society
Date: 09-03-2017
Publisher: Springer Science and Business Media LLC
Date: 12-10-2018
DOI: 10.1038/S41375-018-0264-0
Abstract: Following the achievement of deep molecular response on tyrosine kinase inhibitors (TKIs), approximately half of patients with chronic myeloid leukemia (CML) can discontinue TKI and remain in treatment-free remission (TFR). The ALLG CML8 study enrolled 40 imatinib-treated patients with undetectable BCR-ABL1 mRNA (approximately MR
Publisher: Elsevier BV
Date: 03-2008
Publisher: American College of Physicians
Date: 20-02-2018
DOI: 10.7326/M17-1094
Publisher: Springer Science and Business Media LLC
Date: 05-2010
DOI: 10.1038/LEU.2010.71
Publisher: American Society of Hematology
Date: 03-05-2012
DOI: 10.1182/BLOOD-2011-10-385658
Abstract: Chronic myeloid leukemia in chronic phase (CML-CP) is induced by BCR-ABL1 oncogenic tyrosine kinase. Tyrosine kinase inhibitors eliminate the bulk of CML-CP cells, but fail to eradicate leukemia stem cells (LSCs) and leukemia progenitor cells (LPCs) displaying innate and acquired resistance, respectively. These cells may accumulate genomic instability, leading to disease relapse and/or malignant progression to a fatal blast phase. In the present study, we show that Rac2 GTPase alters mitochondrial membrane potential and electron flow through the mitochondrial respiratory chain complex III (MRC-cIII), thereby generating high levels of reactive oxygen species (ROS) in CML-CP LSCs and primitive LPCs. MRC-cIII–generated ROS promote oxidative DNA damage to trigger genomic instability, resulting in an accumulation of chromosomal aberrations and tyrosine kinase inhibitor–resistant BCR-ABL1 mutants. JAK2(V617F) and FLT3(ITD)–positive polycythemia vera cells and acute myeloid leukemia cells also produce ROS via MRC-cIII. In the present study, inhibition of Rac2 by genetic deletion or a small-molecule inhibitor and down-regulation of mitochondrial ROS by disruption of MRC-cIII, expression of mitochondria-targeted catalase, or addition of ROS-scavenging mitochondria-targeted peptide aptamer reduced genomic instability. We postulate that the Rac2-MRC-cIII pathway triggers ROS-mediated genomic instability in LSCs and primitive LPCs, which could be targeted to prevent the relapse and malignant progression of CML.
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 12-10-2013
Publisher: American Society of Clinical Oncology (ASCO)
Date: 09-2009
Abstract: Nilotinib is a second-generation tyrosine kinase inhibitor indicated for the treatment of patients with chronic myeloid leukemia (CML) in chronic phase (CP CML-CP) and accelerated phase (AP CML-AP) who are resistant to or intolerant of prior imatinib therapy. In this subanalysis of a phase II study of nilotinib in patients with imatinib-resistant or imatinib-intolerant CML-CP, the occurrence and impact of baseline and newly detectable BCR-ABL mutations were assessed. Baseline mutation data were assessed in 281 (88%) of 321 patients with CML-CP in the phase II nilotinib registration trial. Among imatinib-resistant patients, the frequency of mutations at baseline was 55%. After 12 months of therapy, major cytogenetic response (MCyR) was achieved in 60%, complete cytogenetic response (CCyR) in 40%, and major molecular response (MMR) in 29% of patients without baseline mutations versus 49% (P = .145), 32% (P = .285), and 22% (P = .366), respectively, of patients with mutations. Responses in patients who harbored mutations with high in vitro sensitivity to nilotinib (50% inhibitory concentration [IC 50 ] ≤ 150 nM) or mutations with unknown nilotinib sensitivity were equivalent to those responses for patients without mutations (not significant). Patients with mutations that were less sensitive to nilotinib in vitro (IC 50 150 nM Y253H, E255V/K, F359V/C) had less favorable responses, as 13%, 43%, and 9% of patients with each of these mutations, respectively, achieved MCyR none achieved CCyR. For most patients with imatinib resistance and with mutations, nilotinib offers a substantial probability of response. However, mutational status at baseline may influence response. Less sensitive mutations that occurred at three residues defined in this study, as well as the T315I mutation, may be associated with less favorable responses to nilotinib.
Publisher: American Society of Hematology
Date: 07-07-2016
DOI: 10.1182/BLOOD-2016-01-694265
Abstract: The dramatic success of tyrosine kinase inhibitors (TKIs) has led to the widespread perception that chronic myeloid leukemia (CML) has become another chronic disease, where lifelong commitment to pharmacologic control is the paradigm. Recent trials demonstrate that some CML patients who have achieved stable deep molecular response can safely cease their therapy without relapsing (treatment free remission [TFR]). Furthermore, those who are unsuccessful in their cessation attempt can safely re-establish remission after restarting their TKI therapy. Based on the accumulated data on TFR, we propose that it is now time to change our approach for the many CML patients who have achieved a stable deep molecular response on long-term TKI therapy. Perhaps half of these patients could successfully achieve TFR if offered the opportunity. For many of these patients ongoing therapy is impairing quality of life and imposing a heavy financial burden while arguably achieving nothing. This recommendation is based on the evident safety of cessation attempts and TFR in the clinical trial setting. We acknowledge that there are potential risks associated with cessation attempts in wider clinical practice, but this should not deter us. Instead we need to establish criteria for safe and appropriate TKI cessation. Clinical trials will enable us to define the best strategies to achieve TFR, but clinicians need guidance today about how to approach this issue with their patients. We outline circumstances in which it would be in the patient's best interest to continue TKI, as well as criteria for a safe TFR attempt.
Publisher: American Society of Hematology
Date: 27-02-2014
DOI: 10.1182/BLOOD-2013-06-510396
Abstract: More patients with chronic myeloid leukemia in chronic phase achieve EMR on frontline nilotinib than imatinib. EMR failure on frontline nilotinib or imatinib predicts poor outcomes in patients with chronic myeloid leukemia in chronic phase.
Publisher: American Society of Clinical Oncology (ASCO)
Date: 20-01-2010
Abstract: To evaluate the safety and efficacy of initial treatment with imatinib mesylate 800 mg/d (400 mg twice daily) versus 400 mg/d in patients with newly diagnosed chronic myeloid leukemia in chronic phase. A total of 476 patients were randomly assigned 2:1 to imatinib 800 mg (n = 319) or 400 mg (n = 157) daily. The primary end point was the major molecular response (MMR) rate at 12 months. At 12 months, differences in MMR and complete cytogenetic response (CCyR) rates were not statistically significant (MMR, 46% v 40% P = .2035 CCyR, 70% v 66% P = .3470). However, MMR occurred faster among patients randomly assigned to imatinib 800 mg/d, who had higher rates of MMR at 3 and 6 months compared with those in the imatinib 400-mg/d arm (P = .0035 by log-rank test). CCyR also occurred faster in the 800-mg/d arm (CCyR at 6 months, 57% v 45% P = .0146). The most common adverse events were edema, gastrointestinal problems, and rash, and all were more common in patients in the 800-mg/d arm. Grades 3 to 4 hematologic toxicity also occurred more frequently in patients receiving imatinib 800 mg/d. MMR rates at 1 year were similar with imatinib 800 mg/d and 400 mg/d, but MMR and CCyR occurred earlier in patients treated with 800 mg/d. Continued follow-up is needed to determine the clinical significance of earlier responses on high-dose imatinib.
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 07-02-2012
Publisher: Springer Science and Business Media LLC
Date: 03-2017
DOI: 10.1038/NATURE21702
Abstract: Chronic myeloid leukaemia (CML) is driven by the activity of the BCR-ABL1 fusion oncoprotein. ABL1 kinase inhibitors have improved the clinical outcomes for patients with CML, with over 80% of patients treated with imatinib surviving for more than 10 years. Second-generation ABL1 kinase inhibitors induce more potent molecular responses in both previously untreated and imatinib-resistant patients with CML. Studies in patients with chronic-phase CML have shown that around 50% of patients who achieve and maintain undetectable BCR-ABL1 transcript levels for at least 2 years remain disease-free after the withdrawal of treatment. Here we characterize ABL001 (asciminib), a potent and selective allosteric ABL1 inhibitor that is undergoing clinical development testing in patients with CML and Philadelphia chromosome-positive (Ph
Publisher: The Endocrine Society
Date: 08-2010
DOI: 10.1210/JC.2010-0086
Abstract: The mechanism(s) by which imatinib improves glycemic control in chronic myeloid leukemia (CML) patients with type 2 diabetes remains unclear. Adiponectin is an important regulator of insulin sensitivity that is secreted exclusively by adipocytes. We previously reported that imatinib promotes adipocytic differentiation of mesenchymal stromal cells. We therefore hypothesized that imatinib therapy would be associated with an increase in peripheral and intramedullary adiposity and elevated plasma adiponectin levels. Adiponectin levels in CML patient plasma, at diagnosis and then during imatinib mesylate therapy, was measured using an ELISA. Adiponectin multimers in plasma were analyzed using nondenaturing PAGE and immunoblotting. Intramedullary adiposity and adipose tissue mass was determined using histomorphometry and dual-energy X-ray absorptiometry, respectively. In CML patients, an increase in intramedullary and peripheral adiposity was observed after 6 months of imatinib therapy and plasma adiponectin levels, in the form of high- and low-molecular-weight complexes, were elevated 3-fold, compared with pretreatment levels, after 3, 6, and 12 months of therapy. Elevated adiponectin levels in imatinib-treated CML patients provide a possible mechanism for improved glucose and lipid metabolism reported for some imatinib-treated patients.
Publisher: American Society of Hematology
Date: 06-12-2013
DOI: 10.1182/ASHEDUCATION-2013.1.168
Abstract: With the approval in many countries of nilotinib and dasatinib for frontline therapy in chronic myeloid leukemia, clinicians now have to make a difficult choice. Because none of the 3 available tyrosine kinase inhibitors (TKIs) have shown a clear survival advantage, they all represent reasonable choices. However, in in idual patients, the case may be stronger for a particular TKI. In the younger patient, in whom the prospect of eventually achieving treatment-free remission is likely to be of great importance, dasatinib or nilotinib may be preferred, although their advantage over imatinib in this setting remains to be proven. In patients with a higher risk of transformation (which is currently based on prognostic scoring), the more potent TKIs may be preferred because they appear to be more effective at reducing the risk of transformation to BC. However, imatinib still represents an excellent choice for many chronic myeloid leukemia patients. All of these considerations need to be made in the context of the patient's comorbidities, which may lead to one or more TKIs being ruled out of contention. Whatever first choice of TKI is made, treatment failure or intolerance must be recognized early because a prompt switch to another TKI likely provides the best chance of achieving optimal response.
Publisher: American Society of Hematology
Date: 24-12-2009
DOI: 10.1182/BLOOD-2009-08-215939
Abstract: Preclinical studies of BCR-ABL mutation sensitivity to nilotinib or dasatinib suggested that the majority would be sensitive. Correspondingly, the initial clinical trials demonstrated similar response rates for CML patients after imatinib failure, irrespective of the mutation status. However, on closer examination, clinical evidence now indicates that some mutations are less sensitive to nilotinib (Y253H, E255K/V, and F359V/C) or dasatinib (F317L and V299L). T315I is insensitive to both. Novel mutations (F317I/V/C and T315A) are less sensitive/insensitive to dasatinib. We refer to these collectively as second-generation inhibitor (SGI) clinically relevant mutations. By in vitro analysis, other mutations confer a degree of insensitivity however, clinical evidence is currently insufficient to define them as SGI clinically relevant. Here we examine the mutations that are clearly SGI clinically relevant, those with minimal impact on response, and those for which more data are needed. In our series of patients with mutations at imatinib cessation and/or at nilotinib or dasatinib commencement, 43% had SGI clinically relevant mutations, including 14% with T315I. The frequency of SGI clinically relevant mutations was dependent on the disease phase at imatinib failure. The clinical data suggest that a mutation will often be detectable after imatinib failure for which there is compelling clinical evidence that one SGI should be preferred.
Publisher: Springer Japan
Date: 2016
Publisher: Informa UK Limited
Date: 02-01-2021
Publisher: American Society of Hematology
Date: 31-07-2014
DOI: 10.1182/BLOOD-2013-12-544015
Abstract: Nilotinib induced deeper molecular responses than continued imatinib in patients with minimal residual disease on long-term imatinib. These deeper responses may enable more patients to benefit from treatment-free remission trials.
Publisher: Springer Science and Business Media LLC
Date: 23-03-2014
DOI: 10.1007/S12185-014-1566-2
Abstract: The TOPS trial evaluated high- (800 mg/day n = 319) versus standard-dose (400 mg/day n = 157) imatinib in patients newly diagnosed with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase. Patients had a minimum follow-up of 42 months or discontinued early. Major molecular response (MMR) rates were similar between arms at (51.6 vs 50.2 % for 400 and 800 mg/day, respectively P = 0.77) and by (75.8 vs 79.0 % P = 0.4807) 42 months. There were no differences in event-free survival (EFS), progression-free survival(PFS), or overall survival (OS) between arms. The estimated rates of PFS on treatment and OS at 42 months were significantly higher in patients with MMR at 6, 12, and 18 months compared with those without MMR.Adverse events were more frequent with high-dose imatinib. Patients with B1 treatment interruption (vs [1) and those able to maintain imatinib C600 mg/day (vs\\600 mg/day) in the first year of treatment had faster and higher response rates, but no improvement in EFS or PFS. Adherence to prescribed dose without interruption may be more important than initiation of therapy with higher doses of imatinib. Achievement of MMR correlated with longterm clinical outcomes.
Publisher: American Society of Hematology
Date: 14-04-2016
DOI: 10.1182/BLOOD-2015-09-666214
Abstract: The association between multiple BCR-ABL1 mutations and inferior response to nilotinib/dasatinib was not seen with ponatinib therapy. However, chronic phase patients with T315I plus additional mutation(s) did have poorer responses to ponatinib than those with T315I only.
Publisher: Springer Science and Business Media LLC
Date: 30-07-2009
DOI: 10.1038/LEU.2009.156
Abstract: Dasatinib is a highly potent BCR-ABL inhibitor that has shown durable efficacy in patients with chronic phase (CP) chronic myeloid leukemia (CML) after resistance, suboptimal response, or intolerance to prior imatinib. In patients with CML, BCR-ABL transcript measurement is the most sensitive method for assessing minimal residual disease. Here, molecular responses were analyzed in 1067 patients with CML-CP treated with dasatinib during phase II/III trials. After 3, 6, 12, and 24 months of follow-up, a major molecular response (MMR) was achieved by 12, 22, 35, and 40% of patients, respectively. The 24-month MMR rate was 34% in patients with resistance or suboptimal response to imatinib (n=829) and 63% in imatinib-intolerant patients (n=238). Among patients who had achieved a complete cytogenetic response (CCyR), 72% also achieved MMR. Responses with dasatinib 100 mg once daily were similar to other doses. In landmark analyses, 24-month progression-free survival was higher in patients who had achieved MMR or CCyR at 12 months than in those without MMR or CCyR at 12 months. MMR at 12 months was associated with a longer duration of CCyR. Overall, this analysis shows that dasatinib treatment results in high MMR rates in patients with CML-CP after imatinib failure.
Publisher: Springer Science and Business Media LLC
Date: 11-2008
DOI: 10.1038/LEU.2008.231
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 21-09-2017
Publisher: Springer Science and Business Media LLC
Date: 18-12-2008
DOI: 10.1038/LEU.2008.356
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.CELL.2017.11.007
Abstract: Activating mutations of FLT3 occur in about 30% of acute myeloid leukemia (AML) cases and are associated with relapse and poor prognosis. Midostaurin is the first drug approved for AML since 2000, and the first multi-kinase inhibitor approved for the FLT3-mutant subtype. To view this Bench to Bedside, open or download the PDF.
Publisher: Springer Science and Business Media LLC
Date: 23-07-2009
DOI: 10.1038/LEU.2009.150
Publisher: Springer Science and Business Media LLC
Date: 22-03-2009
DOI: 10.1007/S11899-009-0009-2
Abstract: Tyrosine kinase inhibitor (TKI) therapy has significantly changed the treatment paradigm for patients with chronic myeloid leukemia (CML). The first-generation inhibitor, imatinib, has demonstrated remarkable efficacy in most chronic-phase patients. Disease progression remains a significant risk for the first 2 to 3 years of TKI therapy, but the risk falls significantly thereafter. Early recognition of each in idual's risk of progression may facilitate a customized approach to TKI therapy. Using such an approach, drug selection and treatment intensity would be adjusted on the basis of each patient's disease profile. Currently available prognostic indicators have limited value in the setting of the potent kinase inhibition afforded by TKIs. Furthermore, these indicators provide little guidance regarding optimal drug choice and dose intensity. In the future, assays that directly assess the efficacy of the protein-drug interaction, taking into account factors intrinsic to the patient and the amount of drug freely available in the plasma, are likely to be of greater value.
Publisher: American Society of Hematology
Date: 11-02-2016
DOI: 10.1182/BLOOD-2015-08-660977
Abstract: Ponatinib induces durable responses regardless of baseline BCR-ABL1 mutation status in CP-CML patients. No single or compound mutant consistently confers primary or secondary resistance to ponatinib in CP-CML.
Publisher: Begell House
Date: 2012
DOI: 10.1615/CRITREVONCOG.V17.I1.30
Abstract: Chronic myeloid leukemia (CML) is caused by the formation of the BCR-ABL fusion protein as a result of the t(9 ) chromosomal translocation. The elucidation of its molecular pathogenesis led to the identification of a therapeutic target and the subsequent synthesis and introduction of a small-molecule inhibitor for this target, imatinib. Because CML is the first disease successfully treated by targeted kinase inhibition, it served as a paradigm for discovery of disease mechanism and drug development in other diseases in which constitutive kinase expression plays a central role in pathogenesis. Despite the spectacular success of imatinib, not all CML patients derive great benefit from it. This review will cover some of the currently known prognostic markers of disease response and potential resistance mechanisms.
Publisher: Springer Science and Business Media LLC
Date: 02-12-2017
DOI: 10.1038/LEU.2016.335
Publisher: Wiley
Date: 12-07-2017
DOI: 10.1111/BJH.14829
Publisher: Wiley
Date: 28-10-2011
DOI: 10.1002/CNCR.26391
Publisher: Elsevier BV
Date: 06-2013
DOI: 10.1016/J.CYTOGFR.2013.03.002
Abstract: The GM-CSF, IL-3 and IL-5 family of cytokines, also known as the βc family due to their receptors sharing the signalling subunit βc, regulates multiple biological processes such as native and adaptive immunity, inflammation, normal and malignant hemopoieis, and autoimmunity. Australian scientists played a major role in the discovery and biological characterisation of the βc cytokines and their recent work is revealing unique features of cytokine receptor assembly and signalling. Furthermore, specific antibodies have been generated to modulate their function. Characterisation of the structural and dynamic requirements for the activation of the βc receptor family and the molecular definition of downstream signalling pathways are providing new insights into cytokine receptor signalling as well as new therapeutic opportunities.
Publisher: Springer Science and Business Media LLC
Date: 13-07-2013
DOI: 10.1038/LEU.2012.193
Publisher: Wiley
Date: 22-07-2023
DOI: 10.1111/BJH.18984
Abstract: The addition of interferon to tyrosine kinase inhibitors (TKIs), to improve deep molecular response (DMR) and potentially treatment‐free remission (TFR) rates in chronic‐phase chronic myeloid leukaemia (CP‐CML) patients is under active investigation. However, the immunobiology of this combination is poorly understood. We performed a comprehensive longitudinal assessment of immunological changes in CML patients treated with nilotinib and interferon‐alpha (IFN‐α) within the ALLG CML11 trial ( n = 12) or nilotinib alone ( n = 17). We demonstrate that nilotinib+IFN transiently reduced absolute counts of natural killer (NK) cells, compared with nilotinib alone. Furthermore, CD16 + ‐cytolytic and CD57 + CD62L − ‐mature NK cells were transiently reduced during IFN therapy, without affecting NK‐cell function. IFN transiently increased cytotoxic T‐lymphocyte (CTL) responses to leukaemia‐associated antigens (LAAs) proteinase‐3, BMI‐1 and PRAME and had no effect on regulatory T cells, or myeloid‐derived suppressor cells. Patients on nilotinib+IFN who achieved MR4.5 by 12 months had a significantly higher proportion of NK cells expressing NKp46, NKp30 and NKG2D compared with patients not achieving this milestone. This difference was not observed in the nilotinib‐alone group. The addition of IFN to nilotinib drives an increase in NK‐activating receptors, CTLs responding to LAAs and results in transient immune modulation, which may influence earlier DMR, and its effect on long‐term outcomes warrants further investigation.
Publisher: American Association for Cancer Research (AACR)
Date: 15-06-2008
DOI: 10.1158/1078-0432.CCR-07-5095
Abstract: Purpose: The organic cation transporter OCT-1 mediates active transport of imatinib. We recently showed that low OCT-1 activity is a major contributor to suboptimal response in chronic myeloid leukemia (CML) patients treated with imatinib. The relevance of OCT-1 activity and efflux pumps in determining intracellular uptake and retention (IUR) of dasatinib was assessed. Experimental Design: The effect of OCT inhibitors on [14C]dasatinib and [14C]imatinib IUR was compared using peripheral blood mononuclear cells from newly diagnosed CML patients. The role of efflux transporters was studied using ABCB1- and ABCG2-overexpressing cell lines and relevant inhibitors. Results: Unlike imatinib, there was no significant difference in the dasatinib IUR at 37°C and 4°C (P = 0.8), and OCT-1 inhibitors including prazosin did not reduce dasatinib IUR significantly. In CML mononuclear cells, prazosin inhibitable IUR was significantly higher for imatinib than dasatinib (6.38 versus 1.48 ng/200,000 cells P = 0.002 n = 11). Patients with high OCT-1 activity based on their imatinib uptake had IC50dasatinib values equivalent to patients with low OCT-1 activity. Dasatinib IUR was significantly lower in ABCB1-overexpressing cell lines compared with parental cell lines (P & 0.05). PSC833 (ABCB1 inhibitor) significantly increased the dasatinib IUR (P & 0.05) and reduced IC50dasatinib (from 100 to 8 nmol/L) in K562-DOX cell line. The ABCG2 inhibitor Ko143 significantly increased dasatinib IUR in ABCG2-overexpressing cell lines and reduced IC50dasatinib. Conclusion: Unlike imatinib, dasatinib cellular uptake is not significantly affected by OCT-1 activity, so that expression and function of OCT-1 is unlikely to affect response to dasatinib. Dasatinib is a substrate of both efflux proteins, ABCB1 and ABCG2.
Publisher: Informa UK Limited
Date: 30-06-2011
DOI: 10.3109/10428194.2011.591013
Abstract: There are three currently identified secondary resistance mechanisms observed in patients with chronic myeloid leukemia (CML) receiving tyrosine kinase inhibitors (TKIs). These are BCR-ABL kinase domain (KD) mutations, increased BCR-ABL expression, and overexpression of drug-efflux proteins (ABCB1 and ABCG2). To investigate the interplay between these three modes of resistance, three CML blast crisis cell lines (K562, its ABCB1-overexpressing variant K562 Dox, and KU812) were cultured in gradually increasing concentrations of imatinib to 2 μM, or dasatinib to 200 nM. Eight imatinib- and two dasatinib-resistant cell lines were established. Two imatinib-resistant K562 lines both had increased BCR-ABL expression as the apparent mode of resistance. However, when a dasatinib-resistant K562 culture was generated we observed gradually increasing BCR-ABL expression which peaked prior to identification of the T315I mutation. BCR-ABL overexpression followed by mutation development was observed in a further 4/10 cell lines, each with different KD mutations. In contrast, three imatinib-resistant K562 Dox lines exhibited only a further increase in ABCB1 expression. All TKI-resistant cell lines generated had increased IC(50) (dose of drug required to reduce phosphorylation of the adaptor protein p-Crkl by 50%) to imatinib, dasatinib, and nilotinib, regardless of which TKI was used to induce resistance. This suggests that currently available TKIs share the same susceptibilities to drug resistance.
Publisher: Springer Science and Business Media LLC
Date: 13-03-2018
Publisher: Springer Science and Business Media LLC
Date: 11-02-2010
DOI: 10.1038/LEU.2010.16
Abstract: Active influx of imatinib in chronic myeloid leukemia (CML) cells is mediated by the organic cation transporter 1 (OCT-1). Functional activity of OCT-1 (OCT-1 Activity) in mononuclear cells is an excellent predictor of molecular response over the first 24 months of imatinib therapy for chronic phase patients. CML progenitor cells are less sensitive to imatinib-induced apoptosis and are likely contributors to disease persistence. We investigated whether alterations in the expression and function of OCT-1 have a role in imatinib resistance in progenitors. We found the intracellular uptake and retention (IUR) of imatinib, OCT-1 Activity and OCT-1 mRNA expression are all significantly lower in CML CD34+ cells compared with mature CD34- cells (P<0.001). However, no differences in IUR or OCT-1 Activity were observed between these subsets in healthy donors. In contrast to OCT-1, ABCB1 and ABCG2 seemed to have no functional role in the transport of imatinib in CML CD34+ cells. Consistent with the observation that nilotinib uptake is not OCT-1 dependent, the IUR of nilotinib did not differ between CML CD34+ and CD34- cells. These results indicate that low imatinib accumulation in primitive CML cells, mediated through reduced OCT-1 Activity may be a critical determinant of long-term disease persistence.
Publisher: Impact Journals, LLC
Date: 03-02-2018
Publisher: American Society of Hematology
Date: 15-04-2008
Publisher: Springer Science and Business Media LLC
Date: 02-04-2013
Publisher: Springer Science and Business Media LLC
Date: 05-07-2012
DOI: 10.1038/LEU.2012.181
Abstract: Nilotinib (Tasigna) is a BCR-ABL1 tyrosine kinase inhibitor approved for the treatment of patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase (CML-CP) who are newly diagnosed or intolerant of or resistant to imatinib. The 48-month follow-up data for patients with CML-CP treated with nilotinib after imatinib resistance or intolerance on an international phase II study were analyzed. Overall, 59% of patients achieved major cytogenetic response 45% achieved complete cytogenetic response while on study. The estimated rate of overall survival (OS) and progression-free survival (PFS) at 48 months was 78% and 57%, respectively. Deeper levels of molecular responses at 3 and 6 months were highly positively correlated with long-term outcomes, including PFS and OS at 48 months. Of the 321 patients initially enrolled in the study, 98 (31%) were treated for at least 48 months. Discontinuations were primarily due to disease progression (30%) or adverse events (21%). Nilotinib is safe and effective for long-term use in responding patients with CML-CP who are intolerant of or resistant to imatinib. Further significant improvements in therapy are required for patients who are resistant or intolerant to imatinib.
Publisher: Wiley
Date: 03-2009
Publisher: Informa UK Limited
Date: 09-07-2013
Publisher: Springer Science and Business Media LLC
Date: 12-03-2009
DOI: 10.1038/LEU.2009.38
Abstract: Imatinib mesylate is considered standard of care for first-line treatment of chronic phase chronic myeloid leukemia (CML-CP). In the phase III, randomized, open-label International Randomized Study of Interferon vs STI571 (IRIS) trial, previously untreated CML-CP patients were randomized to imatinib (n=553) or interferon-alpha (IFN) plus cytarabine (n=553). This 6-year update focuses on patients randomized to receive imatinib as first-line therapy for newly diagnosed CML-CP. During the sixth year of study treatment, there were no reports of disease progression to accelerated phase (AP) or blast crisis (BC). The toxicity profile was unchanged. The cumulative best complete cytogenetic response (CCyR) rate was 82% 63% of all patients randomized to receive imatinib and still on study treatment showed CCyR at last assessment. The estimated event-free survival at 6 years was 83%, and the estimated rate of freedom from progression to AP and BC was 93%. The estimated overall survival was 88% -- or 95% when only CML-related deaths were considered. This 6-year update of IRIS underscores the efficacy and safety of imatinib as first-line therapy for patients with CML.
Publisher: Elsevier BV
Date: 04-2008
DOI: 10.1080/00313020801916172
Abstract: Chronic myeloid leukaemia (CML) is a molecularly defined disease. The BCR-ABL fusion occurs in all cases of classical CML and leukaemic cells express a constitutively activated BCR-ABL tyrosine kinase. Other fusion oncogenes involving tyrosine kinases, including ABL and PDGFRA/B, have been identified, and are associated with leukaemic syndromes that may resemble CML. The discovery and treatment of these related disorders has been facilitated by our detailed understanding of CML. Imatinib mesylate has significantly improved the outcome of patients with CML, but there remains a significant minority of chronic phase CML patients for whom the response to treatment with standard dose imatinib is suboptimal. Cytogenetic and molecular monitoring of the response to treatment provides important prognostic information. Achievement of a major molecular response (MMR) in chronic phase patients treated de novo with imatinib confers near 100% freedom from progression to advanced phase, and MMR is now an important goal of therapy. Standardisation of BCR-ABL molecular monitoring is under way and should enable the accurate and reproducible identification of MMR in laboratories around the world. Point mutations in the kinase domain of BCR-ABL are the most common cause of acquired resistance to imatinib treatment. The susceptibility of a mutation to imatinib, nilotinib, or dasatinib may help to guide changes in therapy in a patient with resistance. In addition to these established methods of monitoring, there are new tests in development that may assist in determining prognosis and optimising therapy. Among patients receiving the same dose of imatinib, the plasma level of imatinib shows considerable inter-patient variation, and there is emerging evidence that higher levels may be associated with improved response to treatment. The intracellular concentration of imatinib also shows considerable variation, most likely related to differences in influx and efflux transport mechanisms. We discuss how these established and emerging assays might be used to optimise the treatment of CML patients.
Publisher: Elsevier BV
Date: 10-2010
DOI: 10.1053/J.SEMINHEMATOL.2010.06.007
Abstract: Current routine monitoring strategies for chronic myeloid leukemia (CML) incorporate hematologic, cytogenetic, and molecular analysis. BCR-ABL1 kinase domain mutation analysis is an important assessment in specific circumstances. The recommendations for when and how frequently to undertake these assessments have recently been updated. However, response assessment is not always straightforward and access to some analytical tools may not be available. Pharmacokinetic assessment of imatinib levels may correlate with clinical response and could help in assessing issues of suboptimal response, excessive toxicity, or noncompliance. Here we provide practical considerations for monitoring response, offer suggestions for alternative assessments in case of failure or limited access of analyses, and consider future monitoring tools.
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 02-02-2017
Publisher: Massachusetts Medical Society
Date: 07-11-2013
Publisher: Elsevier BV
Date: 02-2008
DOI: 10.1053/J.SEMINONCOL.2007.12.002
Abstract: The treatment of chronic myelogenous leukemia (CML) has been revolutionized by the development of the small-molecule tyrosine kinase inhibitor imatinib. The primary target for this drug is the oncogenic BCR-ABL kinase. Five-year survival rates for patients in chronic phase CML is now greater than 80%. Patients who have advanced beyond the chronic phase to the accelerated phase or blast crisis, however, have not faired as well. Progression occurs for a variety of reasons, including late diagnosis, slow response to imatinib, and the development of imatinib-resistant clones. Imatinib resistance has, in part, been addressed with the introduction of the new BCR-ABL inhibitors, namely dasatinib and nilotinib. These drugs have shown efficacy in CML patients with wild-type BCR-ABL and some BCR-ABL mutants that are imatinib-resistant. Unfortunately, some BCR-ABL mutations remain resistant to these therapies and will require the development of alternative treatments, and other mechanisms of imatinib resistance besides BCR-ABL mutation exist. In the future, genetic and pharmacologic tests may allow the clinician to predict response to imatinib. More aggressive therapies are being considered for high-risk patients, including increased dosage of the current tyrosine kinase inhibitors, along with combination therapies. Aggressive therapy holds promise, as the data suggest that responses are improved. Unfortunately, toxicities are also increased, and thus a balance must be found to ensure safety and compliance. This is especially important for young CML patients, who hopefully will remain in remission for decades. Polymerase chain reaction analysis has become of primary importance as a means of assessing disease burden, and given the idiosyncrasies of this technique, standards must be established to allow results to be compared across different institutions. Additionally, the nature of advanced disease is being explored. Intriguingly, genetic analysis of transformed blasts from patients in blast crisis has identified numerous members of the Wnt/B-catenin pathway and JunB as being activated. Increased activity of these pathways correlates with poor response and eventual disease progression. In addition to these data, evidence is emerging associating survival of the quiescent blast cell with Wnt activity, leading to the hope that Wnt inhibitors will increase the likelihood of eradicating these cells. Other areas such as microRNA profiling and DNA methylation patterns are likely to provide important information.
Publisher: Informa UK Limited
Date: 10-2010
Abstract: The Src/Abl tyrosine kinase inhibitor dasatinib is an approved chronic myeloid leukemia treatment and is under investigation for solid tumor therapy. Members of the Src family of kinases (SFKs) are involved in the process of metastasis and dasatinib inhibits the migration and invasiveness of human melanoma cell lines in vitro. SFKs are also involved in immune function and angiogenesis, which both contribute to As active and passive immunotherapies continue to be investigated in metastatic melanoma, we investigated possible interactions between kinase inhibitors and immunotherapies. A murine syngenic model of metastatic melanoma in which B16F10 cells expressed ovalbumin (B16-OVA) was employed and the active immunotherapy comprised immunization with an OVA-expressing recombinant fowlpox virus (FPVOVA).Dasatinib did not affect B16-OVA viability, proliferation, migration or soft agar colony formation. However, depending on drug dose and schedule, differences in the metastatic behavior of B16-OVA were observed in vivo after dasatinib therapy. At a dose of 5 mg/kg/day given before tumor challenge, dasatinib therapy reduced the number of pulmonary metastases. Conversely, a higher dose (25 mg/kg/day), did not affect the number of pulmonary metastases and increased the number of extra-pulmonary metastases. Finally, immunization of B16-OVA-bearing mice with FPVOVA reduced the number of lung metastases. Prior treatment of these mice with dasatinib 5 mg/kg/day did not affect the incidence of lung metastases. Although the mechanisms by which dasatinib alters the metastatic behavior of B16-OVA cells in vivo remain to be determined, we hypothesize that dasatinib acts via multiple tumor-extrinsic processes that include immune function and neoangiogenesis.
Publisher: American Society of Hematology
Date: 15-11-2008
DOI: 10.1182/BLOOD-2008-06-161737
Abstract: We conducted a trial in 103 patients with newly diagnosed chronic phase chronic myeloid leukemia (CP-CML) using imatinib 600 mg/day, with dose escalation to 800 mg/day for suboptimal response. The estimated cumulative incidences of complete cytogenetic response (CCR) by 12 and 24 months were 88% and 90%, and major molecular responses (MMRs) were 47% and 73%. In patients who maintained a daily average of 600 mg of imatinib for the first 6 months (n = 60), MMR rates by 12 and 24 months were 55% and 77% compared with 32% and 53% in patients averaging less than 600 mg (P = .037 and .016, respectively). Dose escalation was indicated for 17 patients before 12 months for failure to achieve, or maintain, major cytogenetic response at 6 months or CCR at 9 months but was only possible in 8 patients (47%). Dose escalation was indicated for 73 patients after 12 months because their BCR-ABL level remained more than 0.01% (international scale) and was possible in 45 of 73 (62%). Superior responses achieved in patients able to tolerate imatinib at 600 mg suggests that early dose intensity may be critical to optimize response in CP-CML. The trial was registered at www.ANZCTR.org.au as #ACTRN12607000614493.
Publisher: Springer Science and Business Media LLC
Date: 13-02-2015
DOI: 10.1038/LEU.2015.35
Publisher: Springer Science and Business Media LLC
Date: 05-03-2009
DOI: 10.1038/LEU.2009.43
Publisher: American Society of Hematology
Date: 15-02-2008
DOI: 10.1182/BLOOD-2007-04-083196
Abstract: Patients with imatinib-resistant or -intolerant accelerated-phase chronic myelogenous leukemia (CML-AP) have very limited therapeutic options. Nilotinib is a highly selective BCR-ABL tyrosine kinase inhibitor. This phase 2 trial was designed to characterize the efficacy and safety of nilotinib (400 mg twice daily) in this patient population with hematologic response (HR) as primary efficacy endpoint. A total of 119 patients were enrolled and had a median duration of treatment of 202 days (range, 2–611 days). An HR was observed in 56 patients (47% 95% confidence interval [CI], 38%-56%). Major cytogenetic response (MCyR) was observed in 35 patients (29% 95% CI, 21%-39%). The median duration of HR has not been reached. Overall survival rate among the 119 patients after 12 months of follow-up was 79% (95% CI, 70%-87%). Nonhematologic adverse events were mostly mild to moderate. Severe peripheral edema and pleural effusions were not observed. The most common grade 3 or higher hematologic adverse events were thrombocytopenia (35%) and neutropenia (21%). Grade 3 or higher bilirubin and lipase elevations occurred in 9% and 18% of patients, respectively, resulting in treatment discontinuation in one patient. In conclusion, nilotinib is an effective and well-tolerated treatment in imatinib-resistant and -intolerant CML-AP. This trial is registered at www.clinicaltrials.gov as NCT00384228.
Publisher: Springer Science and Business Media LLC
Date: 05-03-2009
DOI: 10.1038/LEU.2009.45
Publisher: Springer Science and Business Media LLC
Date: 16-10-2013
DOI: 10.1038/LEU.2012.295
Publisher: Springer Science and Business Media LLC
Date: 10-2012
DOI: 10.1038/LEU.2012.175
Publisher: American Society of Hematology
Date: 24-07-2014
DOI: 10.1182/BLOOD-2014-03-566323
Abstract: Among patients with % BCR-ABL1, at 3 months, the poorest-risk group can be distinguished by the rate of BCR-ABL1 decline from baseline. Patients with BCR-ABL1 values on a constant downward trajectory may rapidly reach the level considered optimal with additional follow-up.
Publisher: American Society of Clinical Oncology (ASCO)
Date: 10-12-2009
Abstract: To review and update the European LeukemiaNet (ELN) recommendations for the management of chronic myeloid leukemia with imatinib and second-generation tyrosine kinase inhibitors (TKIs), including monitoring, response definition, and first- and second-line therapy. These recommendations are based on a critical and comprehensive review of the relevant papers up to February 2009 and the results of four consensus conferences held by the panel of experts appointed by ELN in 2008. Cytogenetic monitoring was required at 3, 6, 12, and 18 months. Molecular monitoring was required every 3 months. On the basis of the degree and the timing of hematologic, cytogenetic, and molecular results, the response to first-line imatinib was defined as optimal, suboptimal, or failure, and the response to second-generation TKIs was defined as suboptimal or failure. Initial treatment was confirmed as imatinib 400 mg daily. Imatinib should be continued indefinitely in optimal responders. Suboptimal responders may continue on imatinb, at the same or higher dose, or may be eligible for investigational therapy with second-generation TKIs. In instances of imatinib failure, second-generation TKIs are recommended, followed by allogeneic hematopoietic stem-cell transplantation only in instances of failure and, sometimes, suboptimal response, depending on transplantation risk.
Publisher: Springer Science and Business Media LLC
Date: 13-04-2008
DOI: 10.1038/NATURE06866
Abstract: The Philadelphia chromosome, a chromosomal abnormality that encodes BCR-ABL1, is the defining lesion of chronic myelogenous leukaemia (CML) and a subset of acute lymphoblastic leukaemia (ALL). To define oncogenic lesions that cooperate with BCR-ABL1 to induce ALL, we performed a genome-wide analysis of diagnostic leukaemia s les from 304 in iduals with ALL, including 43 BCR-ABL1 B-progenitor ALLs and 23 CML cases. IKZF1 (encoding the transcription factor Ikaros) was deleted in 83.7% of BCR-ABL1 ALL, but not in chronic-phase CML. Deletion of IKZF1 was also identified as an acquired lesion at the time of transformation of CML to ALL (lymphoid blast crisis). The IKZF1 deletions resulted in haploinsufficiency, expression of a dominant-negative Ikaros isoform, or the complete loss of Ikaros expression. Sequencing of IKZF1 deletion breakpoints suggested that aberrant RAG-mediated recombination is responsible for the deletions. These findings suggest that genetic lesions resulting in the loss of Ikaros function are an important event in the development of BCR-ABL1 ALL.
Publisher: Wiley
Date: 06-11-2015
Publisher: Springer Science and Business Media LLC
Date: 11-09-2023
Publisher: Springer Science and Business Media LLC
Date: 10-04-2008
DOI: 10.1038/LEU.2008.84
Abstract: Dasatinib, a potent inhibitor of BCR-ABL in vitro, is effective for patients with chronic myelogenous leukemia (CML) resistant or intolerant to imatinib. To provide a more definitive assessment of dasatinib in chronic-phase (CP)-CML, we report extended follow-up of a phase II trial, presenting data for the entire patient cohort (N=387). Dasatinib (70 mg) twice daily was administered to patients with imatinib-resistant or -intolerant CP-CML. With median follow-up of 15.2 months (treatment duration, <1-18.4 months), a complete hematologic response was attained or maintained in 91% of patients. A major cytogenetic response (MCyR) was attained or maintained by 59% (52% imatinib resistant and 80% imatinib intolerant) this was complete in 49% of patients (40% imatinib resistant and 75% imatinib intolerant). Of 230 patients achieving an MCyR, 7 experienced disease progression. Fifteen-month progression-free survival was 90% while overall survival was 96%. Grade 3/4 thrombocytopenia and neutropenia were reported in 48 and 49% of patients, respectively. Non-hematologic toxicity (any grade) consisted primarily of diarrhea (37%), headache (32%), fatigue (31%), dyspnea (30%) and pleural effusion (27%). Pleural effusions were classified as grade 3 in 6% of reported events, with no incidence of grade 4. Dasatinib is associated with high response rates in patients with imatinib-resistant or -intolerant CP-CML.
Publisher: American Association for Cancer Research (AACR)
Date: 31-10-2011
DOI: 10.1158/1078-0432.CCR-11-0396
Abstract: Purpose: Imatinib induces a durable response in most patients with Philadelphia chromosome–positive chronic myeloid leukemia, but it is currently unclear whether imatinib reduces the leukemic stem cell (LSC) burden, which may be an important step toward enabling safe discontinuation of therapy. In this article, we use mathematical models of BCR–ABL levels to make inferences on the dynamics of LSCs. Experimental Design: Patients with at least 1 BCR–ABL transcript measurement on imatinib were included (N = 477). Maximum likelihood methods were used to test 3 potential hypotheses of the dynamics of BCR–ABL transcripts on imatinib therapy: (i) monoexponential, in which there is little, if any, decline in BCR–ABL transcripts (ii) biexponential, in which patients have a rapid initial decrease in BCR–ABL transcripts followed by a more gradual response and (iii) triexponential, in which patients first exhibit a biphasic decline but then have a third phase when BCR–ABL transcripts increase rapidly. Results: We found that most patients treated with imatinib exhibit a biphasic decrease in BCR–ABL transcript levels, with a rapid decrease during the first few months of treatment, followed by a more gradual decrease that often continues over many years. Conclusions: We show that the only hypothesis consistent with current data on progenitor cell turnover and with the long-term, gradual decrease in the BCR–ABL levels seen in most patients is that these patients exhibit a continual, gradual reduction of the LSCs. This observation may explain the ability to discontinue imatinib therapy without relapse in some cases. Clin Cancer Res 17(21) 6812–21. ©2011 AACR.
Publisher: Springer Science and Business Media LLC
Date: 19-11-2007
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 22-10-2011
Publisher: Wiley
Date: 27-05-2022
DOI: 10.1111/BJH.18277
Publisher: Springer Science and Business Media LLC
Date: 12-05-2021
DOI: 10.1038/S41375-021-01260-Y
Abstract: The ENESTop study evaluated treatment-free remission (TFR) in patients with chronic myeloid leukemia (CML) in chronic phase who had received ≥3 years of tyrosine kinase inhibitor therapy and achieved sustained deep molecular response only after switching from imatinib to nilotinib. After 1-year nilotinib consolidation, 126 patients attempted TFR. At 48 weeks (primary analysis), 57.9% (73/126) were in TFR. In the present analysis at 5 years, 42.9% (54/126) were in TFR. Since the 48-week analysis, among patients who left the TFR phase, 58% (11/19) did not have a loss of molecular response and discontinued for other reasons. Of the 59 patients who reinitiated nilotinib upon loss of major molecular response (MMR) or confirmed loss of MR
Publisher: Elsevier BV
Date: 09-2011
Publisher: Elsevier BV
Date: 04-2017
Publisher: American Society of Hematology
Date: 11-11-2010
DOI: 10.1182/BLOOD-2010-03-273979
Abstract: This study examines the prognostic significance of early molecular response using an expanded dataset in chronic myeloid leukemia patients enrolled in the International Randomized Study of Interferon and STI571 (IRIS). Serial molecular studies demonstrate decreases in BCR-ABL transcripts over time. Analyses of event-free survival (EFS) and time to progression to accelerated phase/blast crisis (AP/BC) at 7 years were based on molecular responses using the international scale (IS) at 6-, 12-, and 18-month landmarks. Patients with BCR-ABL transcripts 10% at 6 months and 1% at 12 months had inferior EFS and higher rate of progression to AP/BC compared with all other molecular response groups. Conversely, patients who achieved major molecular response [MMR: BCR-ABL (IS) ≤ 0.1%] by 18 months enjoyed remarkably durable responses, with no progression to AP/BC and 95% EFS at 7 years. The probability of loss of complete cytogenetic response by 7 years was only 3% for patients in MMR at 18 months versus 26% for patients with complete cytogenetic response but not MMR (P .001). This study shows a strong association between the degree to which BCR-ABL transcript numbers are reduced by therapy and long-term clinical outcome, supporting the use of time-dependent molecular measures to determine optimal response to therapy. This study is registered at www.clinicaltrials.gov as NCT00006343.
Publisher: Springer Science and Business Media LLC
Date: 22-02-2016
DOI: 10.1038/LEU.2016.34
Abstract: Early molecular response (EMR, BCR-ABL1 (IS)⩽10% at 3 months) is a strong predictor of outcome in imatinib-treated chronic phase chronic myeloid leukemia (CP-CML) patients, but for patients who transform early, 3 months may be too late for effective therapeutic intervention. Here, we employed multiplex cytokine profiling of plasma s les to test newly diagnosed CP-CML patients who subsequently received imatinib treatment. A wide range of pro-inflammatory and angiogenesis-promoting cytokines, chemokines and growth factors were elevated in the plasma of CML patients compared with that of healthy donors. Most of these normalized after tyrosine kinase inhibitor treatment while others remained high in remission s les. Importantly, we identified TGF-α and IL-6 as novel biomarkers with high diagnostic plasma levels strongly predictive of subsequent failure to achieve EMR and deep molecular response, as well as transformation to blast crisis and event-free survival. Interestingly, high TGF-α alone can also delineate a poor response group raising the possibility of a pathogenic role. This suggests that the incorporation of these simple measurements to the diagnostic work-up of CP-CML patients may enable therapy intensity to be in idualized early according to the cytokine-risk profile of the patient.
Publisher: Elsevier BV
Date: 04-2009
DOI: 10.1053/J.SEMINHEMATOL.2009.01.008
Abstract: Imatinib is the standard of care for previously untreated chronic myeloid leukemia (CML), with high response rates that lead to improved event-free and overall survival compared with interferon alfa. Imatinib dose is one important factor affecting response, and early clinical studies showed promising molecular response rates with high-dose therapy. Large, randomized trials are now ongoing to test this potential benefit and establish whether a starting dose of 800 mg/d improves long-term clinical outcomes compared with the current standard dose of 400 mg/d. Low plasma imatinib levels are associated with a decreased chance of response. The importance of imatinib dosing and plasma levels is likely due to their impact on intracellular concentrations of the drug. Cellular influx of imatinib is mediated by the OCT-1 protein, and patients with low OCT-1 activity may benefit from dose-intensive therapy. For nonresponding or slowly responding patients, dose escalation to 600 to 800 mg/d may lead to durable responses in patients with primary or secondary resistance. Regular monitoring of response is crucial to maximize therapeutic success, and improved understanding of the factors affecting response will guide future clinical strategies.
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 29-12-2012
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2011
Publisher: American Society of Hematology
Date: 15-11-2018
DOI: 10.1182/BLOOD-2018-05-848630
Abstract: With the advent of tyrosine kinase inhibitors (TKIs), the goals of therapy in chronic myeloid leukemia (CML) are steadily shifting. Long-term disease control on TKI therapy has been the goal and expectation for most patients. More recently, treatment-free remission (TFR) has entered mainstream practice and is increasingly being adopted as the main goal of therapy. This therapeutic shift not only influences TKI selection but also, has necessitated the refinement and dissemination of highly sensitive and accurate molecular monitoring techniques. Measurement of BCR-ABL1 messenger RNA expression through reverse transcription quantitative polymerase chain reaction, reported according to the International Scale, has become the primary tool for response assessment in CML. Achieving specific time-dependent molecular milestones, as defined by global therapeutic guidelines, has been established as critical in maximizing optimal outcomes while identifying patients at risk of therapy failure. Depth and duration of a deep molecular response have become the new therapeutic targets in patients considered for TFR. Consequently, molecular monitoring in CML has become even more critical to ongoing response assessment, identifying patients with TKI resistance and poor drug adherence, and enabling TFR to be attempted safely and effectively.
Publisher: Springer Science and Business Media LLC
Date: 23-02-2011
DOI: 10.1038/CLPT.2011.12
Publisher: Springer Science and Business Media LLC
Date: 20-04-2022
Location: Australia
No related grants have been discovered for Timothy Hughes.