ORCID Profile
0000-0002-5095-7981
Current Organisations
University of South Australia
,
SA Pathology
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
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: 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: 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: SAGE Publications
Date: 31-07-2016
Abstract: Molecular monitoring plays an essential role in the clinical management of chronic myeloid leukemia (CML) patients, and now guides clinical decision making. Quantitative reverse-transcriptase-polymerase-chain-reaction (qRT-PCR) assessment of BCR-ABL1 transcript levels has become the standard of care protocol in CML. However, further developments are required to assess leukemic burden more efficiently, monitor minimal residual disease (MRD), detect mutations that drive resistance to tyrosine kinase inhibitor (TKI) therapy and identify predictors of response to TKI therapy. Cartridge-based BCR-ABL1 quantitation, digital PCR and next generation sequencing are ex les of technologies which are currently being explored, evaluated and translated into the clinic. Here we review the emerging molecular methods/technologies currently being developed to advance molecular monitoring in CML.
Publisher: Springer Science and Business Media LLC
Date: 07-11-2019
DOI: 10.1007/S11899-019-00549-1
Abstract: Identification of the BCR-ABL1 fusion oncogene in patients diagnosed with chronic myeloid leukemia (CML) led to the development of targeted therapy responsible for the dramatic survival benefits observed in the past two decades. However, despite these revolutionary findings, there remains marked disparity in patient outcomes. Why do some patients present de novo while others evolve to the more aggressive stages of CML? Why can select patients successfully discontinue therapy as part of a treatment-free remission attempt whereas others fail to meet specific molecular milestones? BCR-ABL1 kinase mutations are only identified in approximately 50% of patients with poor responses and disease progression, suggesting the presence of alternative resistance mechanisms. Numerous institutions have identified the presence of additional genomic events in addition to BCR-ABL1 with the increasing availability of next-generation sequencing. We explore the potential pathways and events that may cooperate with BCR-ABL1 to answer these questions but also challenge the fundamental tenet that BCR-ABL1 is always the sole event initiating CML.
Publisher: American Society of Hematology
Date: 10-2005
DOI: 10.1182/BLOOD-2005-03-1103
Abstract: Most patients with de novo chronic myeloid leukemia (CML) achieve good responses to imatinib, but the rate and degree of molecular response is variable. We assessed the inhibitory concentration 50% for imatinib (IC50imatinib) in 62 patients with de novo chronic-phase CML as a predictor of molecular response. IC50imatinib was determined in pretherapy blood s les by measuring the in vitro imatinib-induced reduction of the phosphorylated form of the adaptor protein Crkl (CT10 regulator of kinase like). There was marked variability between patients, with IC50imatinib ranging from 0.375 to 1.8 μM (median, 0.6 μM). Patients with low IC50imatinib (IC50 ≤ 0.6 μM n = 36) had a 36% probability of achieving 2-log reduction in BCR-ABL (breakpoint cluster region-abelson) by 3 months compared with 8% in patients with high IC50imatinib (n = 26) (P = .01). The IC50imatinib was also predictive of molecular response at 12 months, with 47% of patients in the low IC50imatinib group achieving 3-log reduction and 23% in the high IC50imatinib group (P = .03). The predictive power of IC50imatinib was particularly strong in patients with low Sokal scores. These data provide strong evidence that intrinsic sensitivity to imatinib is variable in previously untreated patients with CML, and the actual level of BCR-ABL kinase inhibition achieved is critical to imatinib response. The IC50imatinib potentially provides a new prognostic indicator for molecular response in patients treated with imatinib. (Blood. 2005 106:2520-2526)
Publisher: Massachusetts Medical Society
Date: 09-10-2003
DOI: 10.1056/NEJMOA030513
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: 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: American Society of Hematology
Date: 07-2003
DOI: 10.1182/BLOOD-2002-09-2896
Abstract: Imatinib-treated chronic myeloid leukemia (CML) patients with acquired resistance commonly have detectable BCR-ABL kinase domain mutations. It is unclear whether patients who remain sensitive to imatinib also have a significant incidence of mutations. We evaluated 144 patients treated with imatinib for BCR-ABL kinase domain mutations by direct sequencing of 40 accelerated phase (AP), 64 late chronic phase (≥ 12 months from diagnosis, late-CP), and 40 early-CP patients. Mutations were detected in 27 patients at 17 different residues, 13 (33%) of 40 in AP, 14 (22%) of 64 in late-CP, and 0 of 40 in early-CP. Acquired resistance was evident in 24 (89%) of 27 patients with mutations. Twelve (92%) of 13 patients with mutations in the adenosine triphosphate (ATP) binding loop (P-loop) died (median survival of 4.5 months after the mutation was detected). In contrast, only 3 (21%) of 14 patients with mutations outside the P-loop died (median follow-up of 11 months). As the detection of mutations was strongly associated with imatinib resistance, we analyzed features that predicted for their detection. Patients who commenced imatinib more than 4 years from diagnosis had a significantly higher incidence of mutations (18 [41%] of 44) compared with those treated within 4 years (9 [9%] of 100), P & .0001. Lack of a major cytogenetic response (MCR) was also associated with a higher likelihood of detecting a mutation 19 (38%) of 50 patients without a MCR had mutations compared with 8 (8.5%) of 94 with an MCR, P & .0001. In conclusion, the detection of kinase domain mutations using a direct sequencing technique was almost always associated with imatinib resistance, and patients with mutations in the P-loop had a particularly poor prognosis. (Blood. 2003 102:276-283)
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 17-09-2020
DOI: 10.3324/HAEMATOL.2019.240739
Abstract: The primary goal of tyrosine kinase inhibitor (TKI) therapy for patients with chronic myeloid leukemia is survival, which is achieved by the vast majority of patients. The initial response to therapy provides a sensitive measure of future clinical outcome. Measurement of BCR-ABL1 transcript levels using real-time quantitative polymerase chain reaction standardized to the international reporting scale is now the principal recommended monitoring strategy. The method is used to assess early milestone responses and provides a guide for therapeutic intervention. When patients successfully traverse the critical first 12 months of TKI therapy, most will head towards another milestone response, deep molecular response (DMR, BCR-ABL1 ≤0.01%). DMR is essential for patients aiming to achieve treatment-free remission and a prerequisite for a trial of TKI discontinuation. The success of discontinuation trials has led to new treatment strategies in order for more patients to reach this milestone response. DMR has been incorporated into endpoints of clinical trials and is considered by some expert groups as the optimal treatment response. But is DMR a stable response and does it provide the ultimate protection against TKI resistance and death? Do we need to increase the sensitivity of detection of BCR-ABL1 to better identify the patients who would likely remain in treatment-free remission after TKI discontinuation? Is it necessary to switch current TKI therapy to a more potent inhibitor if the goal is to achieve DMR? These are issues that I will explore in this review.
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: Ferrata Storti Foundation (Haematologica)
Date: 31-07-2013
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: MDPI AG
Date: 11-12-2020
Abstract: Vast transcriptomics and epigenomics changes are characteristic of human cancers, including leukaemia. At remission, we assume that these changes normalise so that omics-profiles resemble those of healthy in iduals. However, an in-depth transcriptomic and epigenomic analysis of cancer remission has not been undertaken. A striking exemplar of targeted remission induction occurs in chronic myeloid leukaemia (CML) following tyrosine kinase inhibitor (TKI) therapy. Using RNA sequencing and whole-genome bisulfite sequencing, we profiled s les from chronic-phase CML patients at diagnosis and remission and compared these to healthy donors. Remarkably, our analyses revealed that abnormal splicing distinguishes remission s les from normal controls. This phenomenon is independent of the TKI drug used and in striking contrast to the normalisation of gene expression and DNA methylation patterns. Most remarkable are the high intron retention (IR) levels that even exceed those observed in the diagnosis s les. Increased IR affects cell cycle regulators at diagnosis and splicing regulators at remission. We show that aberrant splicing in CML is associated with reduced expression of specific splicing factors, histone modifications and reduced DNA methylation. Our results provide novel insights into the changing transcriptomic and epigenomic landscapes of CML patients during remission. The conceptually unanticipated observation of widespread aberrant alternative splicing after remission induction warrants further exploration. These results have broad implications for studying CML relapse and treating minimal residual disease.
Publisher: American Society of Hematology
Date: 03-2007
Publisher: Springer Science and Business Media LLC
Date: 17-06-2019
Publisher: Informa UK Limited
Date: 11-01-2019
DOI: 10.1080/10428194.2018.1551533
Abstract: The management of CML in pregnancy is challenging with the need to balance disease control against potential teratogenic effects of TKI therapy. In this multi-center case-cohort study of 16 women in chronic phase, CML ceased TKI treatment pre- or post-conception during their first pregnancy. Thirteen patients were on imatinib 9 ceased their TKI prior to conception and 7 ceased at pregnancy confirmation. Twelve patients had achieved either MMR or better at time of TKI cessation. Eleven women lost MMR during pregnancy and two patients lost CHR. Fourteen women reestablished MMR on TKI recommenced. The depth molecular response prior to conception appeared to correlate well with restoration of disease control on TKI recommencement though duration of MMR did not appear to be as important. While interruption of TKI treatment for pregnancy usually leads to loss of molecular response, loss of hematological response is uncommon and disease control is reestablished with resumption of therapy in the majority of women.
Publisher: American Society of Hematology
Date: 25-11-2021
Publisher: American Society of Hematology
Date: 2007
DOI: 10.1182/ASHEDUCATION-2007.1.376
Abstract: The role of molecular monitoring for patients with chronic myeloid leukemia (CML) is multifaceted. Milestone measurements up to 18 months of first-line imatinib therapy are prognostic and provide warning signals of suboptimal response. Serial measurements for patients with a complete cytogenetic response determine ongoing treatment efficacy or signal pending relapse. The pattern of molecular and cytogenetic response is generally comparable, but only cytogenetic analysis can monitor for the acquisition of clonal abnormalities and has an important role in case of loss of molecular response. For patients treated with imatinib, a rising level of BCR-ABL is a trigger for kinase domain mutation analysis. The characterization of BCR-ABL inhibitor-resistant mutations is important to direct therapeutic intervention because it is now apparent that each resistant mutation functions as a distinct protein with unique biological properties that may confer a gain or loss of function. The benefit to patients of regular molecular analysis is a reassurance of ongoing response using the most sensitive of techniques or a potential improvement in outcome for those where relapse is indicated early. However, despite the obvious benefits of molecular analysis, the measurement techniques may not be quite ready for acceptance into the routine clinical monitoring practices of all clinicians. The challenge now is to standardize and simplify the method so that it can be readily and reliably incorporated into routine laboratory testing procedures.
Publisher: American Association for Cancer Research (AACR)
Date: 12-2007
DOI: 10.1158/1078-0432.CCR-07-0844
Abstract: Purpose: In the first years of imatinib treatment, BCR-ABL remained detectable in all but a small minority of patients with chronic myeloid leukemia. We determined whether BCR-ABL continues to decline with longer imatinib exposure and the incidence and consequence of undetectable BCR-ABL. Experimental Design: BCR-ABL levels were measured in a subset of 53 imatinib-treated IRIS trial patients for up to 7 years (29 first-line, 24 second-line). Levels were deemed undetectable using strict PCR sensitivity criteria. Results: By 18 months, the majority achieved a 3-log reduction [major molecular response (MMR)]. BCR-ABL continued to decline but at a slower rate (median time to 4-log reduction and undetectable BCR-ABL of 45 and 66 months for first-line). The probability of undetectable BCR-ABL increased considerably from 36 to 81 months of first-line imatinib {7% [95% confidence interval (95% CI), 0-17%] versus 52% (95% CI, 32-72%)}. Undetectable BCR-ABL was achieved in 18 of 53 patients and none of these 18 lost MMR after a median follow-up of 33 months. Conversely, MMR was lost in 6 of 22 (27%) patients with sustained detectable BCR-ABL and was associated with BCR-ABL mutations in 3 of 6. Loss of MMR was recently defined as suboptimal imatinib response. There was no difference in the probability of achieving molecular responses between first- and second-line patients but first-line had a significantly higher probability of maintaining MMR [P = 0.03 96% (95% CI, 88-100%) versus 71% (95% CI, 48-93%)]. Conclusions: With prolonged therapy, BCR-ABL continued to decline in most patients and undetectable BCR-ABL was no longer a rare event. Loss of MMR was only observed in patients with sustained detectable BCR-ABL.
Publisher: Elsevier BV
Date: 04-2003
Publisher: Springer Science and Business Media LLC
Date: 14-09-2006
Abstract: Molecular monitoring for patients with chronic myeloid leukaemia (CML) has become an important practice in the era of imatinib therapy. For successful widespread introduction into the mainstream patient monitoring schedule, many procedural aspects of the complex real-time quantitative polymerase chain reaction (RQ-PCR) technique for measuring BCR-ABL transcripts require optimization. Recommendations for harmonizing the differing methodologies have recently been proposed. These recommendations were designed to maximize reliability of analysis for clinical decision making and proposed the adoption of an International Scale of measurement. The purpose of this review is to present the evidence and supporting data for specific recommendations. These recommendations include use of the same source of cells, either blood or marrow, for analysis for validation of equal PCR lification efficiencies of cDNA and standards when using a plasmid to construct standard curves and for ensuring ongoing high-level performance by undertaking a quality assurance programme. Clinicians must know the measurement reliability of an RQ-PCR assay to be able to determine the significance of a change in BCR-ABL level. An assay with poor precision limits the clinical usefulness of results. International harmonization should establish RQ-PCR measurement of BCR-ABL as the best method for monitoring treatment response for patients with CML.
Publisher: Wiley
Date: 26-10-2010
Publisher: Proceedings of the National Academy of Sciences
Date: 16-10-2017
Abstract: Many therapeutic strategies are h ered by the development of drug resistance. High-throughput random mutagenesis screens represent a promising approach for identifying mutations that lead to drug resistance, but have often identified more resistant mutations than are observed in patients, raising questions of their clinical significance. We developed an improved high-throughput mutagenesis screening approach that uses CRISPR-Cas9–based genome editing to generate comprehensive libraries of point mutations at a defined genomic location and systematically study their effect on cell growth. As proof-of-concept, we show our approach accurately predicts the clinical prevalence of drug-resistant mutations in the oncogene BCR-ABL . Our approach can be broadly applied to a variety of oncogenes and represents a new strategy for evaluating resistance susceptibility during drug development.
Publisher: Springer Science and Business Media LLC
Date: 06-08-2022
DOI: 10.1007/S11899-022-00668-2
Abstract: The chronic myeloid leukemia (CML) treatment success story is incomplete as some patients still fail therapy, leading to end-stage disease and death. Here we discuss recent research into CML incidence, the role of comorbidities on survival and detecting patients at risk of failing therapy. The incidence of CML has fallen markedly in high social-demographic index (SDI) regions of the world but there is disturbing evidence that this is not the case in low and low-middle SDI countries. Now that CML patients more frequently die from their co-morbid conditions than from CML the Adult Comorbidity Evaluation-27 score can assist in risk assessment at diagnosis. Non-adherence to therapy contributes greatly to treatment failure. A good doctor-patient relationship and social support promote good adherence, but patient age, gender, and financial burden have negative effects, suggesting avenues for intervention. Mutations in cancer-associated genes adversely affect outcome and their detection at diagnosis may guide therapeutic choice and offer non-BCR::ABL1 targeted therapies. A differential gene expression signature to assist risk detection is a highly sought-after diagnostic tool being actively researched on several fronts. Detecting patients at risk of failing therapy is being assisted by recent technological advances enabling highly sensitive genomic and expression analysis of insensitive cells. However, patient lifestyle, adherence to therapy, and comorbidities are critical risk factors that need to be addressed by interventions such as social and financial support.
Publisher: Elsevier BV
Date: 03-2009
Publisher: Springer Science and Business Media LLC
Date: 25-06-2013
DOI: 10.1038/BJC.2013.318
Publisher: Springer Science and Business Media LLC
Date: 20-11-2009
DOI: 10.1038/LEU.2008.330
Publisher: American Society of Hematology
Date: 02-06-2016
Publisher: Massachusetts Medical Society
Date: 09-03-2017
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 12-09-2014
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: 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: Springer Science and Business Media LLC
Date: 14-05-2019
DOI: 10.1038/S41375-019-0479-8
Abstract: Therapy-related myeloid neoplasms (T-MN) are poorly characterized secondary hematological malignancies following chemotherapy/radiotherapy exposure. We compared the clinical and mutational characteristics of T-MN (n = 129) and primary myelodysplastic syndrome (P-MDS, n = 108) patients. Although the somatic mutation frequency was similar between T-MN and P-MDS patients (93% in both groups), the pattern was distinct. TP53 mutations were more frequent in T-MN (29.5 vs. 7%), while spliceosomal complex mutations were more common in P-MDS (56.5 vs. 25.6%). In contrast to P-MDS, the ring sideroblasts (RS) phenotype was not associated with better survival in T-MN, most probably due to genetic association with TP53 mutations. SF3B1 was mutated in 96% of P-MDS with ≥15% RS, but in only 32% T-MN. TP53 mutations were detected in 92% T-MN with ≥15% RS and SF3B1 wild-type cases. Interestingly, T-MN and P-MDS patients with "Very low" or "Low" Revised International Prognostic Scoring System (IPSS-R) showed similar biological and clinical characteristics. In a Cox regression analysis, TP53 mutation was a poor prognostic factor in T-MN, independent of IPSS-R cytogenetics, disease-modifying therapy, and NRAS mutation. Our data have direct implications for T-MN management and provide evidence that, in addition to conventional disease parameters, mutational analysis should be incorporated in T-MN risk stratification.
Publisher: Springer Science and Business Media LLC
Date: 05-2010
DOI: 10.1038/LEU.2010.71
Publisher: Springer Science and Business Media LLC
Date: 11-08-2020
DOI: 10.1038/S41375-020-01011-5
Abstract: Blast-phase chronic myeloid leukemia (BP-CML) is associated with additional chromosomal aberrations, RUNX1 mutations being one of the most common. Tyrosine kinase inhibitor therapy has only limited efficacy in BP-CML, and characterization of more defined molecular subtypes is warranted in order to design better treatment modalities for this poor prognosis patient group. Using whole-exome and RNA sequencing we demonstrate that PHF6 and BCORL1 mutations, IKZF1 deletions, and AID/RAG-mediated rearrangements are enriched in RUNX1 mut BP-CML leading to typical mutational signature. On transcriptional level interferon and TNF signaling were deregulated in primary RUNX1 mut CML cells and stem cell and B-lymphoid factors upregulated giving a rise to distinct phenotype. This was accompanied with the sensitivity of RUNX1 mut blasts to CD19-CAR T cells in ex vivo assays. High-throughput drug sensitivity and resistance testing revealed leukemia cells from RUNX1 mut patients to be highly responsive for mTOR-, BCL2-, and VEGFR inhibitors and glucocorticoids. These findings were further investigated and confirmed in CRISPR/Cas9-edited homozygous RUNX1 −/− and heterozygous RUNX1 −/mut BCR-ABL positive cell lines. Overall, our study provides insights into the pathogenic role of RUNX1 mutations and highlights personalized targeted therapy and CAR T-cell immunotherapy as potentially promising strategies for treating RUNX1 mut BP-CML patients.
Publisher: Wiley
Date: 27-03-2019
DOI: 10.1111/BJH.15894
Publisher: Wiley
Date: 20-08-2018
Abstract: 2D semiconductors such as transition metal dichalcogenides (TMDs) and black phosphorus (BP) are currently attracting great attention due to their intrinsic bandgaps and strong excitonic emissions, making them potential candidates for novel optoelectronic applications. Optoelectronic devices fabricated from 2D semiconductors exhibit many-body complexes (exciton, trion, biexciton, etc.) which determine the materials optical and electrical properties. Characterization and manipulation of these complexes have become a reality due to their enhanced binding energies as a direct result from reduced dielectric screening and enhanced Coulomb interactions in the 2D regime. Furthermore, the atomic thickness and extremely large surface-to-volume ratio of 2D semiconductors allow the possibility of modulating their inherent optical, electrical, and optoelectronic properties using a variety of different environmental stimuli. To fully realize the potential functionalities of these many-body complexes in optoelectronics, a comprehensive understanding of their formation mechanism is essential. A topical and concise summary of the recent frontier research progress related to many-body complexes in 2D semiconductors is provided here. Moreover, detailed discussions covering the aspects of fundamental theory, experimental investigations, modulation of properties, and optoelectronic applications are given. Lastly, personal insights into the current challenges and future outlook of many-body complexes in 2D semiconducting materials are presented.
Publisher: Oxford University Press (OUP)
Date: 09-07-2013
DOI: 10.1093/BIOINFORMATICS/BTT375
Abstract: Motivation: With the advent of relatively affordable high-throughput technologies, DNA sequencing of cancers is now common practice in cancer research projects and will be increasingly used in clinical practice to inform diagnosis and treatment. Somatic (cancer-only) single nucleotide variants (SNVs) are the simplest class of mutation, yet their identification in DNA sequencing data is confounded by germline polymorphisms, tumour heterogeneity and sequencing and analysis errors. Four recently published algorithms for the detection of somatic SNV sites in matched cancer–normal sequencing datasets are VarScan, SomaticSniper, JointSNVMix and Strelka. In this analysis, we apply these four SNV calling algorithms to cancer–normal Illumina exome sequencing of a chronic myeloid leukaemia (CML) patient. The candidate SNV sites returned by each algorithm are filtered to remove likely false positives, then characterized and compared to investigate the strengths and weaknesses of each SNV calling algorithm. Results: Comparing the candidate SNV sets returned by VarScan, SomaticSniper, JointSNVMix2 and Strelka revealed substantial differences with respect to the number and character of sites returned the somatic probability scores assigned to the same sites their susceptibility to various sources of noise and their sensitivities to low-allelic-fraction candidates. Availability: Data accession number SRA081939, code at /snv-caller-review/ Contact: david.adelson@adelaide.edu.au Supplementary information: Supplementary data are available at Bioinformatics online.
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: 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 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: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.JMOLDX.2022.04.004
Abstract: Mutation detection is increasingly used for the management of hematological malignancies. Prior whole transcriptome and whole exome sequencing studies using total RNA and DNA identified erse mutation types in cancer-related genes associated with treatment failure in patients with chronic myeloid leukemia. Variants included single-nucleotide variants and small insertions/deletions, plus fusion transcripts and partial or whole gene deletions. The hypothesis that all of these mutation types could be detected by a single cost-effective hybridization capture next-generation sequencing method using total RNA was assessed. A method was developed that targeted 130 genes relevant for myeloid and lymphoid leukemia. Retrospective s les with 121 precharacterized variants were tested using total RNA and/or DNA. Concordance of detection of precharacterized variants using RNA or DNA was 96%, whereas the enhanced sensitivity identified additional variants. Comparison between 24 matched DNA and RNA s les demonstrated 95.3% of 170 variants detectable using DNA were detected using RNA, including all but one variant predicted to activate nonsense-mediated decay. RNA identified an additional 10 variants, including fusion transcripts. Furthermore, the true effect of splice variants on RNA splicing was only evident using RNA. In conclusion, capture sequencing using total RNA alone is suitable for detecting a range of variants relevant in chronic myeloid leukemia and may be more broadly applied to other hematological malignancies where erse variant types define risk groups.
Publisher: American Society of Hematology
Date: 02-12-2016
DOI: 10.1182/ASHEDUCATION-2016.1.156
Abstract: Molecular monitoring of BCR-ABL1 transcripts for patients with chronic myeloid leukemia (CML) is now used to assess response to tyrosine kinase inhibitors (TKIs), including treatment failure that mandates a change of therapy. Therefore, many centers have adopted the molecular technique for measuring BCR-ABL1 and rely on conversion of values to the international reporting scale for appropriate clinical interpretation. However, the technique has a degree of inherent variability despite standardized procedures, which means care should be taken by the clinician when assessing response based on BCR-ABL1 cutoff limits. The last few years have witnessed the emergence of a new molecular response target, which is the achievement and maintenance of a deep molecular response. The ability to achieve treatment-free remission for some patients has shifted the relevant boundary for molecular response. However, the definitive safe BCR-ABL1 transcript level and length of the maintenance phase after which treatment cessation can be attempted has not yet been determined. For patients with TKI resistance, BCR-ABL1 kinase domain mutation analysis remains an essential assessment to guide therapy. Furthermore, low-level mutation detection is clinically relevant for response prediction to subsequent TKI therapy for some patients. Multiple low-level mutations may be a biomarker of a clonally erse disease with the propensity for resistance evolution. Overall, molecular monitoring, including low-level monitoring is a fundamental component of management for patients with CML.
Publisher: American Society of Hematology
Date: 21-12-2006
DOI: 10.1182/BLOOD-2006-09-046888
Abstract: The prognosis for patients with chronic myeloid leukemia (CML) in myeloid blast crisis (MBC) or lymphoid blast crisis (LBC) remains poor. Although imatinib can induce responses in a subset of these patients, resistance to the drug develops rapidly. Dasatinib is a novel, oral, multitargeted kinase inhibitor of BCR-ABL and SRC family kinases. After promising phase 1 results, we report the results of phase 2 clinical trials of dasatinib in patients with imatinib-resistant or -intolerant blast crisis CML (MBC, n = 74 LBC, n = 42). At the 8-month follow-up, dasatinib induced major hematologic responses (MaHRs) in 34% and 31% of MBC- and LBC-CML patients and major cytogenetic responses (MCyRs) in 31% and 50% of these patients, respectively. Most (86%) of these MCyRs were complete cytogenetic responses (CCyRs). Responses were rapid and durable: 88% and 46%, respectively, of MBC- and LBC-CML patients achieving MaHR had not experienced disease progression at the 8-month follow-up. Response rates were similar in patients with and without BCR-ABL mutations known to confer resistance to imatinib. Dasatinib was well tolerated. Nonhematologic adverse events were mild to moderate. Cytopenias were common and could be managed by dose modification. Dasatinib is highly active and produces hematologic and cytogenetic responses in a significant number of patients with imatinib-resistant or -intolerant MBC- and LBC-CML. These trials were registered at www.clinicaltrials.gov as #CA180006 and #CA180015.
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 28-02-2019
Publisher: Elsevier BV
Date: 09-2016
DOI: 10.1016/J.BEHA.2016.10.006
Abstract: Over recent years the early response to therapy has been established as a robust and critical determinant of long term outcome to tyrosine kinase inhibitor therapy. Molecular monitoring has taken centre stage with the incorporation of molecular milestone values into treatment recommendations and guidelines. However, establishing a reliable molecular method that is standardized to the international reporting scale is not a trivial undertaking and more recent data suggest that a single timepoint molecular assessment may not be optimal for identifying the patients at highest risk of treatment failure. This review will discuss the evidence for the importance of the early assessment of response for treatment change decisions, the emerging evidence for incorporating additional s le collection timepoints to assess the initial rate of BCR-ABL1 decline and the controversial suggestion that methods be changed to accommodate this analysis.
Publisher: MDPI AG
Date: 26-01-2022
Abstract: Chronic myeloid leukemia (CML) represents the disease prototype of genetically based diagnosis and management. Tyrosine kinase inhibitors (TKIs), that target the causal BCR::ABL1 fusion protein, exemplify the success of molecularly based therapy. Most patients now have long-term survival however, TKI resistance is a persistent clinical problem. TKIs are effective in the BCR::ABL1-driven chronic phase of CML but are relatively ineffective for clinically defined advanced phases. Genomic investigation of drug resistance using next-generation sequencing for CML has lagged behind other hematological malignancies. However, emerging data show that genomic abnormalities are likely associated with suboptimal response and drug resistance. This has already been supported by the presence of BCR::ABL1 kinase domain mutations in drug resistance, which led to the development of more potent TKIs. Next-generation sequencing studies are revealing additional mutations associated with resistance. In this review, we discuss the initiating chromosomal translocation that may not always be a straightforward reciprocal event between chromosomes 9 and 22 but can sometimes be accompanied by sequence deletion, inversion, and rearrangement. These events may biologically reflect a more genomically unstable disease prone to acquire mutations. We also discuss the future role of cancer-related gene mutation analysis for risk stratification in CML.
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: American Society of Hematology
Date: 24-11-2022
Abstract: Myeloid neoplasms and acute leukemias derive from the clonal expansion of hematopoietic cells driven by somatic gene mutations. Although assessment of morphology plays a crucial role in the diagnostic evaluation of patients with these malignancies, genomic characterization has become increasingly important for accurate diagnosis, risk assessment, and therapeutic decision making. Conventional cytogenetics, a comprehensive and unbiased method for assessing chromosomal abnormalities, has been the mainstay of genomic testing over the past several decades and remains relevant today. However, more recent advances in sequencing technology have increased our ability to detect somatic mutations through the use of targeted gene panels, whole-exome sequencing, whole-genome sequencing, and whole-transcriptome sequencing or RNA sequencing. In patients with myeloid neoplasms, whole-genome sequencing represents a potential replacement for both conventional cytogenetic and sequencing approaches, providing rapid and accurate comprehensive genomic profiling. DNA sequencing methods are used not only for detecting somatically acquired gene mutations but also for identifying germline gene mutations associated with inherited predisposition to hematologic neoplasms. The 2022 International Consensus Classification of myeloid neoplasms and acute leukemias makes extensive use of genomic data. The aim of this report is to help physicians and laboratorians implement genomic testing for diagnosis, risk stratification, and clinical decision making and illustrates the potential of genomic profiling for enabling personalized medicine in patients with hematologic neoplasms.
Publisher: American Society of Hematology
Date: 04-07-2019
Publisher: Galenos Yayinevi
Date: 24-08-2022
Publisher: American Society of Hematology
Date: 15-09-2022
Abstract: The classification of myeloid neoplasms and acute leukemias was last updated in 2016 within a collaboration between the World Health Organization (WHO), the Society for Hematopathology, and the European Association for Haematopathology. This collaboration was primarily based on input from a clinical advisory committees (CACs) composed of pathologists, hematologists, oncologists, geneticists, and bioinformaticians from around the world. The recent advances in our understanding of the biology of hematologic malignancies, the experience with the use of the 2016 WHO classification in clinical practice, and the results of clinical trials have indicated the need for further revising and updating the classification. As a continuation of this CAC-based process, the authors, a group with expertise in the clinical, pathologic, and genetic aspects of these disorders, developed the International Consensus Classification (ICC) of myeloid neoplasms and acute leukemias. Using a multiparameter approach, the main objective of the consensus process was the definition of real disease entities, including the introduction of new entities and refined criteria for existing diagnostic categories, based on accumulated data. The ICC is aimed at facilitating diagnosis and prognostication of these neoplasms, improving treatment of affected patients, and allowing the design of innovative clinical trials.
Publisher: Springer Science and Business Media LLC
Date: 02-10-2003
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: 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: 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: 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: Humana Press
Date: 2006
Abstract: The major mechanism of imatinib resistance for patients with chronic myeloid leukemia (CML) is clonal expansion of leukemic cells with mutations in the Bcr-Abl fusion tyrosine kinase that reduce the capacity of imatinib to inhibit kinase activity. The early detection of such mutations may allow timely treatment intervention to prevent or overcome resistance. Direct sequencing of the BCR-ABL kinase domain is relatively rapid and allows detection of emerging mutations at a sensitivity of approx 20%. Mutations have been detected over a range of 242 amino acids, which spans the entire kinase domain. For optimal sensitivity, the kinase domain of the abnormal gene should be isolated by reverse-transcription (RT) polymerase chain reaction (PCR) lification using primers that hybridize to the BCR and ABL genes. The quality of the RNA is assessed by real-time quantitative PCR prior to analysis, and BCR-ABL levels are determined. Only RNA of adequate quality is used to ensure accurate and reproducible mutation analysis. Depending on the level of BCR-ABL transcripts, a one- or two-step PCR is required to lify the kinase domain. Direct sequencing with dye terminator chemistry is performed using PCR-purified products. The sequence is compared to an ABL kinase domain reference sequence using sequencing analysis software, which aligns the sequences and highlights single or multiple mutations.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2019
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: 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: Elsevier BV
Date: 2014
DOI: 10.1016/J.LEUKRES.2013.09.011
Abstract: Patients with chronic myeloid leukemia develop resistance to both first-generation and second-generation tyrosine kinase inhibitors (TKIs) as a result of mutations in the kinase domain (KD) of BCR-ABL1. A wide range of BCR-ABL1 KD mutations that confer resistance to TKIs have been identified, and the T315I mutant has proven particularly difficult to target. This review summarizes the prevalence, impact, and prognostic implications of BCR-ABL1 KD mutations in patients with chronic myeloid leukemia who are treated with current TKIs and provides an overview of recent treatment guidelines and future trends for the detection of mutations.
Publisher: Springer Science and Business Media LLC
Date: 27-10-2015
DOI: 10.1038/LEU.2015.301
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: 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: 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: 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: Springer Science and Business Media LLC
Date: 05-2003
Publisher: Springer Science and Business Media LLC
Date: 03-2011
DOI: 10.1007/S11899-011-0082-1
Abstract: Molecular monitoring is a key component of the management of patients with chronic myeloid leukemia. The current recommendation is that molecular monitoring be performed in place of cytogenetic assessment when a major molecular response (MMR) is achieved. With the more potent kinase inhibitors nilotinib and dasatinib now approved as front-line therapy, more patients will achieve an MMR and will benefit from molecular monitoring. There is a strong correlation between certain BCR-ABL1 levels and the cytogenetic response, which means that molecular monitoring may act as a surrogate for cytogenetic response, but only if the BCR-ABL1 values are converted to the international reporting scale. Furthermore, improvements in the limit of BCR-ABL1 detection and reduction of intra-assay variability are ongoing issues of importance for molecular monitoring. Standardization of molecular methods to accurately assess the patient response also remains a challenge, despite the recent certification of international scale reference materials.
Publisher: Springer Science and Business Media LLC
Date: 10-02-2005
Publisher: Elsevier BV
Date: 2006
DOI: 10.1016/J.BLRE.2005.01.008
Abstract: Molecular monitoring of BCR-ABL transcript levels by real-time quantitative PCR is increasingly used to assess treatment response in patients with chronic myeloid leukaemia (CML). This has become particularly relevant in the era of imatinib therapy when residual levels of leukaemia usually fall below the level of detection by bone marrow cytogenetic analysis. Studies of imatinib-treated patients have determined that BCR-ABL levels measured early in therapy can predict subsequent response and the probability of acquired resistance. The defining of a molecular level of response that indicates a high probability of progression-free survival highlights the relevance of molecular analysis for clinical management. Small increases in the BCR-ABL level can identify patients with kinase domain mutations that lead to imatinib resistance. Therefore, these assays can be used as a screening strategy for mutation analysis. As second generation kinase inhibitors commence clinical trials, the molecular response will be a primary end-point that determines efficacy.
Publisher: Springer Science and Business Media LLC
Date: 16-02-2006
Abstract: Real-time quantitative polymerase chain reaction (PCR) for BCR-ABL mRNA in the peripheral blood (RQ-PCR) provides an accurate and reliable measure of response to therapy in chronic myeloid leukaemia (CML). We wanted to determine in what circumstances additional clinically relevant information was provided by simultaneous cytogenetic analysis in RQ-PCR monitored patients receiving imatinib treatment. We analysed 828 simultaneous RQ-PCR and bone marrow cytogenetic analyses from 183 patients with chronic phase CML with a median follow-up of 20 months. Cytogenetic progression was defined as Philadelphia (Ph)-positive clonal evolution, loss of complete cytogenetic response or an increase of > or = 20% Ph-positive cells. Cytogenetic progression occurred in 24/183 (13%) patients. At the time of cytogenetic progression, none of the 24 patients had a major molecular response (MMR > or = 3-log reduction in BCR-ABL from standardised baseline). There were 320 RQ-PCR results from 95 patients indicating MMR. No abnormality was detected in any of the corresponding cytogenetic analyses. A policy of regular RQ-PCR monitoring with cytogenetic analysis targetted only to patients who have not achieved, or have lost MMR would represent a rational approach to monitoring and spare most patients the discomfort of multiple marrow aspirates. This approach depends upon availability of an accurate, reproducible RQ-PCR assay with ongoing quality assurance.
Publisher: American Society of Hematology
Date: 15-07-2007
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 Society for Clinical Investigation
Date: 04-09-2007
DOI: 10.1172/JCI30890
Publisher: American Society of Hematology
Date: 11-2006
DOI: 10.1182/BLOOD.V108.11.2339.2339
Abstract: Real-time quantitative reverse transcriptase PCR for BCR-ABL (RQ-PCR) is used to monitor treatment response in chronic myeloid leukaemia (CML). BCR-ABL levels continue to decline over several years of imatinib treatment and increasing numbers of patients have BCR-ABL levels at or below the limit of detection. The sensitivity of current RQ-PCR assays limits our ability to identify patients who have a continuing decline in BCR-ABL levels or to assess the effects of novel therapies to improve outcome in patients who have a good response to ABL kinase inhibitors, but harbour minimal residual disease. Improvements in therapy for these patients will be hard to assess without more sensitive monitoring of BCR-ABL. BCR-ABL levels are usually reported relative to a control gene. The control gene value gives an indication of the sensitivity achieved within each RNA s le this varies with s le quality and efficiency of reverse transcription (RT). Control gene copy number below a defined value indicates that the analysis may be unreliable. We investigated the use of a random pentadecamer (RP 15mer) primer in the RT reaction to improve the sensitivity of RQ-PCR. The RP primer is reported to be more efficient than the random hexamer (RH 6mer) which is commonly used for RQ-PCR. BCR-ABL and BCR control gene transcripts were measured in 30 peripheral blood s les. After Trizol extraction 2μg RNA and 400U Superscript II reverse transcriptase were added to two RT reactions using RP or RH at a final concentration of 25μM. Each RT and quantitative PCR was performed 2–3 times and results compared using the Wilcoxon signed rank test or paired t-test. A more efficient RT is indicated by higher transcript levels. The table shows that BCR-ABL and BCR control gene values were significantly higher with RP primers. There was a proportionate increase in all transcripts so that the change in BCR-ABL/BCR% was not significant. BCR-ABL and control gene values with pentadecamer or hexamer primers No. of S les Primer Median 25th Percentile 75th Percentile P value (RP v HP) * missing values due to inclusion of s les with undetectable BCR-ABL BCR transcripts 30 RH 438900 241800 1090000 0.001 RP 1203700 836500 2125000 BCR-ABL transcripts 16* RH 280 110 11340 0.001 RP 390 220 32910 BCR-ABL/BCR ratio 16* RH 0.10% 0.06% 5.6% =0.083 RP 0.08% 0.05% 4.2% We tested s les with undetectable BCR-ABL including 10 from CML patients on imatinib, and 10 from BCR-ABL negative control subjects. Each RNA was tested in two independent RTs and Q-PCRs. If the results were discordant a third RQ-PCR was performed and a consensus result determined. Using RP primers 6/10 patient s les were positive 2/10 were positive with RH. None of the BCR-ABL negative control s les was positive with either primer. Sensitivity was calculated using the lower limit of detection and the standardised baseline value for untreated CML patients.The median calculated sensitivity increased from 4.5-log with RH to 5.0-log with RP. The use of pentadecamer primer made possible the detection of BCR-ABL in a small number of patients who had undetectable BCR-ABL with random hexamer RQ-PCR. This initial analysis suggests that the sensitivity of BCR-ABL detection may be improved 2–3-fold with a simple modification to RT methodology. This also has the potential to reduce the number of s les deemed unsatisfactory due to low control gene levels.
Publisher: Springer Science and Business Media LLC
Date: 26-05-2017
DOI: 10.1038/S41598-017-02655-7
Abstract: We describe a novel ERBB1/EGFR somatic mutation (p. C329R c.985 T C) identified in a patient with JAK2 V617F Polycythaemia Vera (PV). This substitution affects a conserved cysteine residue in EGFR domain 2 and leads to the formation of a ligand-independent covalent receptor dimer, associated with increased transforming potential. Aberrant signalling from the EGFR C329R receptor is cell type-dependent and in the TF1.8 erythroid cell line expression of this mutant suppresses EPO-induced differentiation. Clonal analysis shows that the dominant JAK2 V617F -positive clone in this PV patient harbors EGFR C329R , thus this mutation may contribute to clonal expansion. Somatic mutations affecting other ERBB and related receptor tyrosine kinases are observed in myeloproliferative neoplasms (MPN), and we show elevated EGFR levels in MPN s les, consistent with previous reports. Thus activation of this group of receptors, via multiple mechanisms, may contribute to clonal growth and survival of the JAK2 V617F disease clone in MPN.
Publisher: Wiley
Date: 03-02-2022
DOI: 10.1111/BJH.18046
Publisher: Impact Journals, LLC
Date: 03-02-2018
Publisher: Springer Science and Business Media LLC
Date: 27-08-2009
DOI: 10.1038/LEU.2009.168
Abstract: The high efficacy of the standard treatment of chronic myeloid leukemia (CML) with imatinib has prompted the need for accurate methods to monitor response at levels below the landmark of complete cytogenetic remission. Quantification of BCR-ABL transcripts has proven to be the most sensitive method available, and has shown prognostic impact with regard to progression-free survival. Until recently, variations in methods used to quantify BCR-ABL made it difficult to compare results between laboratories. An international program is now underway to harmonize the reporting of results according to an international scale (IS). In this review, we consider the background to the IS and the progress that has been made to date, with a particular focus on ongoing harmonization efforts in Europe. We provide recommendations for the propagation of the IS by national or regional laboratory networks.
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: Wiley
Date: 06-2002
DOI: 10.1046/J.1365-2141.2002.03508.X
Abstract: We propose a mechanism for dual expression of b2a2 and b3a2 BCR-ABL in chronic myeloid leukaemia (CML). We have identified a BCR allele, present in approximately 29% of the population, which includes an adenine to guanine polymorphism in the putative branchpoint of BCR intron 13. CML patients who expressed both b2a2 and b3a2 transcripts had the allele, which was also associated with alternative transcription of the normal BCR allele. We conclude that the BCR intronic polymorphism is associated with activation of a cryptic branchpoint resulting in reduced efficiency of RNA splicing and exon 14 (b3) skipping in BCR and BCR-ABL.
Publisher: Springer Science and Business Media LLC
Date: 02-04-2013
Publisher: Informa UK Limited
Date: 25-05-2011
Publisher: Springer Science and Business Media LLC
Date: 25-03-2011
DOI: 10.1038/BCJ.2011.10
Publisher: American Society of Hematology
Date: 08-12-2012
DOI: 10.1182/ASHEDUCATION.V2012.1.111.3806846
Abstract: An 80-year-old man has newly diagnosed chronic myeloid leukemia. His BM and blood examination at diagnosis confirms chronic-phase disease, with the Philadelphia chromosome as the sole cytogenetic abnormality. He has intermediate Sokal and Hasford risk,1 and is started on imatinib 600 mg once daily. He lives 5 hours away from the nearest specialist hematology service and prefers followup with his local physician, who cannot perform BM examinations. In patients such as this, is it acceptable to monitor his therapeutic response solely with molecular studies of his peripheral blood?
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: Wiley
Date: 14-06-2021
DOI: 10.1111/BJH.17623
Abstract: With the focus of leukaemia management shifting to the implications of low‐level disease burden, increasing attention is being paid on the development of highly sensitive methodologies required for detection. There are various techniques capable of identification of measurable residual disease (MRD) either evidencing as relevant mutation detection [e.g. nucleophosmin 1 ( NPM1 ) mutation] or trace levels of leukaemic clonal populations. The vast majority of these methods only permit detection of a single clone or mutation. However, mass spectrometry and next‐generation sequencing enable the interrogation of multiple genes simultaneously, facilitating a more complete genomic profile. In the present review, we explore the methodologies of both techniques in conjunction with the important advantages and limitations associated with each assay. We also highlight the evidence and the various instances where either technique has been used and propose future strategies for MRD detection.
Publisher: Springer Science and Business Media LLC
Date: 10-05-2016
Publisher: Elsevier BV
Date: 09-2009
Publisher: American Society of Hematology
Date: 08-12-2012
DOI: 10.1182/ASHEDUCATION.V2012.1.105.3798223
Abstract: Monitoring response to therapy for patients with chronic myeloid leukemia using an effective strategy is fundamental for achieving optimal patient outcomes. It will allow the initiation of timely therapeutic intervention for patients with a suboptimal response or kinase inhibitor therapy failure. Evidence is mounting that reaching molecular targets early in therapy is as important as the initial hematologic and cytogenetic response for the identification of patients who may have a poorer outcome. When the molecular target of a major molecular response is achieved at 18 months, patients reach a safe haven where loss of response is rare. However, this benefit is dependent on continuous drug adherence in most patients. As some patients reach their second decade of successful imatinib therapy, how long will frequent response monitoring be necessary? Assuming that very late relapse will be extremely rare for responding patients remaining on kinase inhibitor therapy, there are reasons for maintaining a regular molecular monitoring frequency, including monitoring adherence assessment and confirming sustained undetectable BCR-ABL1 for those considering a discontinuation trial and for late molecular recurrence in patients who maintain response after treatment discontinuation.
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: Springer Science and Business Media LLC
Date: 25-11-2019
DOI: 10.1038/S41375-019-0647-X
Abstract: Approximately half of patients with chronic myeloid leukemia (CML) in sustained deep molecular response who discontinue tyrosine kinase inhibitors (TKIs) remain in treatment-free remission (TFR). Some of these patients have measurable residual disease (MRD) by BCR-ABL1 mRNA testing, and most have detectable BCR-ABL1 DNA by highly sensitive methods. We used fluorescence-activated cell sorting and BCR-ABL1 DNA PCR to investigate the lineage of residual CML cells in TFR. Twenty patients in TFR for >1 year provided blood for sorting into granulocytes, monocytes, B cells, T cells, and NK cells. MRD was identified predominantly in the lymphoid compartment and never in granulocytes. B cells were more often BCR-ABL1 positive than T cells (18 vs 11/20 patients) and at higher levels (median 10
Publisher: Wiley
Date: 2007
DOI: 10.1002/CNCR.22842
Abstract: Interferon-alpha (IFN-alpha) confers a survival advantage for the minority of patients with chronic myeloid leukemia (CML) who achieve a complete cytogenetic response. The question of whether IFN-alpha-responsive patients can experience further improvements with imatinib has not been answered. Imatinib offers clear quality of life advantages. Furthermore, patients who achieve a major molecular response (MMR) while receiving imatinib are likely to remain progression free. A total of 23 patients treated for a median of 4.5 years with IFN-alpha (range, 1.6-14.3 years) who had achieved a complete (Philadelphia chromosome [Ph] negative, n = 15 patients) or near-complete (1-10% Ph, n = 8 patients) cytogenetic response were studied. The primary objective was to determine whether ceasing therapy with IFN-alpha and switching to 12 months of imatinib treatment at a dose of 400 mg/day could improve the molecular response as assessed by real-time quantitative polymerase chain reaction of BCR-ABL transcript levels. Safety was also assessed. Every patient who had not achieved an MMR while receiving IFN-alpha (n = 16 patients) achieved an MMR after a median of 3 months of imatinib treatment. Significant BCR-ABL reductions (median, 63-fold range, 18-425-fold) occurred in 15 of these patients. Every patient who had already achieved an MMR while receiving IFN-alpha (n = 7 patients) maintained an MMR while receiving imatinib. No patients discontinued imatinib due to toxicity, but 1 patient withdrew consent. These data suggest that switching IFN-alpha-responsive patients to imatinib leads to a rapid improvement in achieving an MMR, a response with established prognostic value, and is well tolerated. The study should help patients and their physicians make evidence-based decisions regarding the potential benefits and risks of switching to imatinib.
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: Wiley
Date: 29-11-2010
DOI: 10.1002/CNCR.25717
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: 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: Wiley
Date: 12-1999
DOI: 10.1046/J.1365-2141.1999.01749.X
Abstract: We have developed a rapid real-time quantitative PCR method for measuring BCR-ABL mRNA levels in peripheral blood in chronic myeloid leukaemia (CML). The technique was used to monitor minimal residual disease for the early detection of relapse and as an assessment of treatment response. Normal BCR mRNA was quantitated to control for RNA degradation and the results reported as a percentage of BCR-ABL/BCR. Every patient measured at diagnosis (n = 21) had increased expression of BCR-ABL of up to 5-fold above the normal BCR levels. With effective treatment the BCR-ABL levels decreased. The molecular data was correlated with Philadelphia chromosome levels in bone marrow and a good correlation was found when treatment induced a cytogenetic response (Spearman correlation = 0.94, P < 0.0001, n = 67 s les). In patients receiving interferon-alpha therapy we found a significant difference in the BCR-ABL levels between cytogenetic response groups. The method was sensitive, reproducible, and readily detected a change in BCR-ABL transcript levels in serial blood s les. S le throughput was high because post PCR processing was unnecessary. We conclude that real-time quantitative PCR monitoring of peripheral blood can be used to reliably monitor disease response in CML.
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: Springer International Publishing
Date: 2021
Publisher: Cold Spring Harbor Laboratory
Date: 04-08-2020
DOI: 10.1101/2020.07.31.20165597
Abstract: Vast transcriptomics and epigenomics changes are characteristic of human cancers including leukemia. At remission, we assume that these changes normalise so that omics-profiles resemble those of healthy in iduals. However, an in-depth transcriptomic and epigenomic analysis of cancer remission has not been undertaken. A striking exemplar of targeted remission induction occurs in chronic myeloid leukemia (CML) following tyrosine kinase inhibitor (TKI) therapy. Using RNA sequencing and whole-genome bisulfite sequencing, we profiled s les from chronic-phase CML patients at diagnosis and remission, and compared these to healthy donors. Remarkably, our analyses revealed that abnormal splicing distinguishes remission s les from normal controls. This phenomenon is independent of the TKI drug used and in striking contrast to the normalisation of gene expression and DNA methylation patterns. Most remarkable are the high intron retention (IR) levels that even exceed those observed in the diagnosis s les. Increased IR affects cell cycle regulators at diagnosis and splicing regulators at remission. We show that aberrant splicing in CML is associated with reduced expression of specific splicing factors, histone modifications and reduced DNA methylation. Our results provide novel insights into the changing transcriptomic and epigenomic landscapes of CML patients during remission. The conceptually unanticipated observation of widespread aberrant alternative splicing after remission induction warrants further exploration. These results have broad implications for studying CML relapse and treating minimal residual disease.
Publisher: Springer Science and Business Media LLC
Date: 25-04-2016
DOI: 10.1038/LEU.2016.90
Publisher: Springer Science and Business Media LLC
Date: 06-2005
DOI: 10.1038/NATURE03669
Abstract: The clinical success of the ABL tyrosine kinase inhibitor imatinib in chronic myeloid leukaemia (CML) serves as a model for molecularly targeted therapy of cancer, but at least two critical questions remain. Can imatinib eradicate leukaemic stem cells? What are the dynamics of relapse due to imatinib resistance, which is caused by mutations in the ABL kinase domain? The precise understanding of how imatinib exerts its therapeutic effect in CML and the ability to measure disease burden by quantitative polymerase chain reaction provide an opportunity to develop a mathematical approach. We find that a four-compartment model, based on the known biology of haematopoietic differentiation, can explain the kinetics of the molecular response to imatinib in a 169-patient data set. Successful therapy leads to a biphasic exponential decline of leukaemic cells. The first slope of 0.05 per day represents the turnover rate of differentiated leukaemic cells, while the second slope of 0.008 per day represents the turnover rate of leukaemic progenitors. The model suggests that imatinib is a potent inhibitor of the production of differentiated leukaemic cells, but does not deplete leukaemic stem cells. We calculate the probability of developing imatinib resistance mutations and estimate the time until detection of resistance. Our model provides the first quantitative insights into the in vivo kinetics of a human cancer.
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: S. Karger AG
Date: 2012
DOI: 10.1159/000334716
Abstract: Achieving a major molecular response (MMR) is an important predictor of progression-free survival in chronic myeloid leukemia patients treated with imatinib. This requires accurate measurement of i BCR-ABL1 /i transcripts normalized to a control gene, as well as defining a level ( i BCR-ABL1 /i /control gene ratio) that will correlate with sustained clinical response. To make these measurements comparable between laboratories, an international scale (IS) is necessary. A i BCR-ABL1 /i /control gene ratio of 0.10% represents MMR in the IS. In collaboration with an international reference laboratory in Adelaide, S.A., Australia, we have established and validated a lab-specific conversion factor for expressing i BCR-ABL1 /i transcript levels in the IS. In this report, we explain the process and steps involved in obtaining a valid lab-specific conversion factor for expressing i BCR-ABL1 /i transcript levels in the IS.
Publisher: Springer Science and Business Media LLC
Date: 19-02-2020
Publisher: Elsevier BV
Date: 10-2015
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 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: Ferrata Storti Foundation (Haematologica)
Date: 07-10-2021
DOI: 10.3324/HAEMATOL.2021.279317
Abstract: Cancer treatment is constantly evolving from a one-size-fits-all towards bespoke approaches for each patient. In certain solid cancers, including breast and lung, tumor genome profiling has been incorporated into therapeutic decision-making. For chronic phase chronic myeloid leukemia (CML), while tyrosine kinase inhibitor therapy is the standard treatment, current clinical scoring systems cannot accurately predict the heterogeneous treatment outcomes observed in patients. Biomarkers capable of segregating patients according to outcome at diagnosis are needed to improve management, and facilitate enrollment in clinical trials seeking to prevent blast crisis transformation and improve the depth of molecular responses. To this end, gene expression (GE) profiling studies have evaluated whether GE signatures at diagnosis are clinically informative. Patient material from a variety of sources has been profiled using microarrays, RNA sequencing and, more recently, single-cell RNA sequencing. However, differences in the cell types profiled, the technologies used, and the inherent complexities associated with the interpretation of genomic data pose challenges in distilling GE datasets into biomarkers with clinical utility. The goal of this paper is to review previous studies evaluating GE profiling in CML, and explore their potential as risk assessment tools for in idualized CML treatment. We also review the contribution that acquired mutations, including those seen in clonal hematopoiesis, make to GE profiles, and how a model integrating contributions of genetic and epigenetic factors in resistance to tyrosine kinase inhibitors and blast crisis transformation can define a route to GE-based biomarkers. Finally, we outline a four-stage approach for the development of GE-based biomarkers in CML.
Publisher: Springer Japan
Date: 2016
Publisher: Oxford University Press (OUP)
Date: 1992
Publisher: Humana Press
Date: 2006
Abstract: Real-time quantitative reverse-transcription polymerase chain reaction (RQ-PCR) methods for the quantitation of BCR-ABL mRNA in the blood of patients with chronic myeloid leukemia (CML) has become the predominant molecular monitoring technique. The BCR-ABL fusion gene is expressed in over 95% of patients with CML, and RQ-PCR provides a reliable, high-throughput method to accurately assess the level of treatment response and provides an early indication of emerging drug resistance. The ABI Prism 7700 Sequence Detection System uses TaqMan fluorogenic probes to quantitate specific nucleic acid sequences using RQ-PCR. The analyzer monitors an increase in fluorescence during the PCR cycle, which is proportional to the amount of accumulated product. The starting copy number is calculated relative to a series of standards. The copy number is normalized to a control gene that compensates for variations in the efficiency of the RT step and for the degree of RNA degradation. In our experience, reliable and consistent RQ-PCR requires thorough validation of all aspects of the procedure, including the selection of an appropriate control gene, careful assay design to avoid polymorphisms in primer or probe binding sites and to exclude the lification of contaminating DNA, and monitoring the performance of the RQ-PCR by the use of quality control s les.
Publisher: Springer Science and Business Media LLC
Date: 14-05-2021
DOI: 10.1038/S41467-021-23097-W
Abstract: Blast crisis (BC) predicts dismal outcomes in patients with chronic myeloid leukaemia (CML). Although additional genetic alterations play a central role in BC, the landscape and prognostic impact of these alterations remain elusive. Here, we comprehensively investigate genetic abnormalities in 136 BC and 148 chronic phase (CP) s les obtained from 216 CML patients using exome and targeted sequencing. One or more genetic abnormalities are found in 126 (92.6%) out of the 136 BC patients, including the RUNX1 - ETS2 fusion and NBEAL2 mutations. The number of genetic alterations increase during the transition from CP to BC, which is markedly suppressed by tyrosine kinase inhibitors (TKIs). The lineage of the BC and prior use of TKIs correlate with distinct molecular profiles. Notably, genetic alterations, rather than clinical variables, contribute to a better prediction of BC prognosis. In conclusion, genetic abnormalities can help predict clinical outcomes and can guide clinical decisions in CML.
Publisher: American Society of Hematology
Date: 31-07-2017
DOI: 10.1182/BLOODADVANCES.2017006825
Abstract: Germ line variants in ASXL1 and BIM are strong biomarkers of response to imatinib in chronic phase CML. A combined Sokal risk and ASXL1 and BIM variant model identified a subgroup of patients with the greatest risk of treatment failure.
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: 11-09-2023
Publisher: Elsevier BV
Date: 12-2019
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: 02-09-2015
DOI: 10.1038/LEU.2014.256
Publisher: Oxford University Press (OUP)
Date: 03-05-2016
DOI: 10.1093/BIOINFORMATICS/BTW239
Abstract: The standard method used by high-throughput genome sequencing facilities for detecting mislabelled s les is to use independently generated high-density SNP data to determine s le identity. However, as it has now become commonplace to have multiple s les sequenced from the same source, such as for analysis of somatic variants using matched tumour and normal s les, we can directly use the genotype information inherent in the sequence data to match s les and thus bypass the need for additional laboratory testing. Here we present BAM-matcher, a tool that can rapidly determine whether two BAM files represent s les from the same biological source by comparing their genotypes. BAM-matcher is designed to be simple to use, provides easily interpretable results, and is suitable for deployment at early stages of data processing pipelines. Availability and implementation: BAM-matcher is licensed under the Creative Commons by Attribution license, and is available from: acgf/bam-matcher . Supplementary information: Supplementary data are available at Bioinformatics online. Contact: paul.wang@sa.gov.au
Publisher: Wiley
Date: 27-05-2022
DOI: 10.1111/BJH.18277
Publisher: American Society of Hematology
Date: 24-08-2023
Abstract: Chronic myeloid leukemia (CML) patients who are eligible for treatment-free remission (TFR) may still relapse after tyrosine kinase inhibitor (TKI) cessation. There is a need for accurate predictors of outcome to enable patients with a favorable profile to proceed while avoiding futile attempts. Sensitive detection of residual disease in total leukocytes at treatment cessation is associated with relapse, but is not highly discriminatory, likely because it is a composite measure of residual leukemia derived from different cell lineages whereas only some lineages are relevant for relapse. We prospectively measured BCR::ABL1 DNA as a predictive yes/no binary test in five cellular fractions from 48 patients meeting conventional criteria for TKI discontinuation. The median BCR::ABL1 DNA level was higher in granulocytes and in T cells, but not in other lineages, in patients who relapsed. In the 40 patients undergoing a first TFR attempt we defined three groups with differing relapse risk: granulocytes-positive (100%), granulocytes-negative/T cells-positive (67%), and granulocytes-negative /T cells-negative (25%). These data show the critical importance of lineage-specific assessment of residual disease in the selection of patients who can attempt TFR with a high expectation of success, and concurrently defer patients who have a high probability of relapse.
Publisher: Springer Science and Business Media LLC
Date: 12-10-2011
DOI: 10.1007/S10147-011-0328-X
Abstract: Real-time quantitative polymerase chain reaction (RQ-PCR) has been widely used for molecular monitoring for patients with chronic myeloid leukemia (CML). Currently, RQ-PCR is not based on the concept of international scale (IS) in Japan mainly because none of the domestic laboratories have obtained their own conversion factor (CF) which makes it possible to convert locally scaled BCR-ABL (BCR-ABL (L)) value to the IS (BCR-ABL (IS)). To join the global trend of molecular assessment of BCR-ABL in CML patients, we have tried to obtain a CF in Japan. S les from 55 patients were exchanged between the Japanese laboratory and the reference laboratory in Adelaide, and BCR-ABL and internal control gene transcripts of the s les were measured using RQ-PCR. The patient bias conversion method was used to determine the CF for the IS using the Bland and Altman method. The local CF in the Japanese laboratory was determined to be 0.87. Based on this CF, 0.1% BCR-ABL (IS), defined as major molecular response, becomes equivalent to 731 copy/μg RNA BCR-ABL (L). This study is the first to introduce a laboratory-specific CF for harmonizing RQ-PCR methodology for detecting BCR-ABL transcripts to Japan, which may open new windows for molecular assessment of CML patients in Japan.
Publisher: American Society of Hematology
Date: 05-2002
Abstract: Point mutations were found in the adenosine triphosphate (ATP) binding region of BCR/ABL in 12 of 18 patients with chronic myeloid leukemia (CML) or Ph-positive acute lymphoblastic leukemia (Ph+ ALL) and imatinib resistance (defined as loss of established hematologic response), but they were found in only 1 of 10 patients with CML with imatinib refractoriness (failure to achieve cytogenetic response). In 10 of 10 patients for whom s les were available, the mutation was not detected before the initiation of imatinib therapy. Three mutations (T315I, Y253H, and F317L present in 3, 1, and 1 patients, respectively) have a predicted role in abrogating imatinib binding to BCR/ABL, whereas 3 other mutations (E255K, G250E, and M351T, present in 4, 2, and 2 patients, respectively) do not. Thus we confirm a high frequency of mutations clustered within the ATP-binding region of BCR/ABL in resistant patients. Screening may allow intervention before relapse by identifying emerging mutations with defined impacts on imatinib binding. Certain mutations may respond to higher doses of imatinib, whereas other mutations may mandate switching to another therapeutic strategy.
Publisher: SAGE Publications
Date: 03-1996
DOI: 10.1177/000456329603300204
Abstract: We have developed an indirect sandwich ELISA for measuring plasma apolipoprotein E (apo-E), using commercially available antibodies. A monoclonal anti-apo-E was used as the capture antibody and the captured apo-E detected with polyclonal anti-apo-E antiserum (goat). The detecting antibody was quantitated using horseradish peroxidase-conjugated rabbit immunoglobulin to goat immunoglobulins. There was no detectable cross-reactivity between the three antisera. Interference with the assay by apolipoprotein A-1, bilirubin and haemoglobin was not significant up to 1·7 g/L, 1250 μmol/L and 13·0 g/dL, respectively. The ELISA method showed high correlation with an established immunonephelometric method (ELISA apo-E=104 Immunonephelometric apo-E+16 r 2 = 0·954, P 0·0001, n = 39). The assay has a measuring range between 5 and 560 mg/L. The coefficient of duplicates was 20%, within-run coefficients of variation (CV) ranged from 3·7 to 6·0% and between-run CV from 6·1 to 15·1%. The reference range determined for 168 normotriglyceridaemic subjects was 20 to 130 mg/L. In an analysis of the lipoprotein subfractions isolated by ultracentrifugation as the fraction of density less than 1·25 g/mL and separated by gel permeation chromatography, apo-E was found to be associated with very low-density lipoprotein and large high-density lipoprotein.
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: 23-03-2023
DOI: 10.3324/HAEMATOL.2022.282184
Abstract: The BCR::ABL1 gene fusion initiates chronic myeloid leukemia (CML), however evidence has accumulated from studies of highly selected cohorts that variants in other cancer-related genes are associated with treatment failure. Nevertheless, the true incidence and impact of additional genetic abnormalities (AGAs) at diagnosis of chronic phase (CP)-CML is unknown. We sought to determine whether AGAs at diagnosis in a consecutive imatinib-treated cohort of 210 patients enrolled in the TIDEL-II trial influenced outcome despite a highly proactive treatment intervention strategy. Survival outcomes including overall survival, progression-free survival, failure-free survival and BCR::ABL1 kinase domain mutation acquisition were evaluated. Molecular outcomes were measured at a central laboratory and included major molecular response (MMR, BCR::ABL1 ≤0.1%IS), MR4 (BCR::ABL1 ≤0.01%IS) and MR4.5 (BCR::ABL1 ≤0.0032%IS). AGAs included variants in known cancer genes and novel rearrangements involving the formation of the Philadelphia chromosome. Clinical outcomes and molecular response were assessed based on the genetic profile and other baseline factors. AGAs were identified in 31% of patients. Potentially pathogenic variants in cancer-related genes were detected in 16% of patients at diagnosis (including gene fusions and deletions) and structural rearrangements involving the Philadelphia chromosome (Ph-associated rearrangements), detected in 18%. Multivariable analysis demonstrated that the combined genetic abnormalities plus the ELTS clinical risk score were independent predictors of lower molecular response rates and higher treatment failure. Despite a highly proactive treatment intervention strategy, first-line imatinib-treated patients with AGAs had poorer response rates. This data provides evidence for the incorporation of genomically-based risk assessment for CML.
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: Elsevier BV
Date: 10-2011
Publisher: American Society of Hematology
Date: 11-2004
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 12-2022
DOI: 10.3324/HAEMATOL.2022.281493
Abstract: Chronic myeloid leukemia is characterized by a single genetic abnormality resulting in a fusion gene whose mRNA product is easily detected and quantified by reverse-transcriptase polymerase chain reaction analysis. Measuring residual disease was originally introduced to identify patients relapsing after allogeneic stem cell transplantation but rapidly adopted to quantify responses to tyrosine kinase inhibitors. Real-time quantitative polymerase chain reaction is now an essential tool for the management of patients and is used to influence treatment decisions. In this review we track this development including the international collaboration to standardize results, discuss the integration of molecular monitoring with other factors that affect patients’ management, and describe emerging technology. Four case histories describe varying scenarios in which the accurate measurement of residual disease identified patients at risk of disease progression and allowed appropriate investigations and timely clinical intervention.
Publisher: Wiley
Date: 06-2000
DOI: 10.1046/J.1365-2141.2000.02042.X
Abstract: An atypical BCR-ABL transcript in a patient with Philadelphia (Ph)-positive chronic myeloid leukaemia (CML) was detected using a long polymerase chain reaction technique. Sequence analysis revealed a joining of BCR exon e8 and ABL exon a2, with a 55-base pair (bp) insert of an inverted sequence of ABL intron 1b between them, giving rise to an in frame e8a2 BCR-ABL transcript. This is the first report of a BCR-ABL transcript with the insertion of an inverted sequence. The long PCR technique is a useful screen for atypical BCR-ABL transcripts not detected by standard techniques.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2011
Publisher: Ferrata Storti Foundation (Haematologica)
Date: 05-07-2018
Publisher: Springer Science and Business Media LLC
Date: 20-04-2022
No related grants have been discovered for Susan Branford.