Response dynamics of pediatric patients with chronic myeloid leukemia on imatinib therapy.
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ABSTRACT:
SUBMITTER: Proschmann R
PROVIDER: S-EPMC5286951 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Imatinib has so far been the first-choice treatment in chronic myeloid leukemia with excellent results. However, only a proportion of patients achieve major molecular response - hence the need to find biological predictors of outcome to select the optimal therapeutic strategy now that more potent inhibitors are available. We investigated a panel of 20 polymorphisms in seven genes, potentially associated with the pharmacogenetics of imatinib, in a subset of 189 patients with newly diagnosed chronic myeloid leukemia enrolled in the TOPS trial. The analysis included polymorphisms in the transporters hOCT1, MDR1, ABCG2, OCTN1, and OATP1A2, and in the metabolizing genes CYP3A4 and CYP3A5. In the overall population, the OCTN1 C allele (rs1050152), a simple combination of polymorphisms in the hOCT1 gene and another combination in the genes involved in imatinib uptake were significantly associated with major molecular response. The combination of polymorphisms in imatinib uptake was also significantly associated with complete molecular response. Analyses restricted to Caucasians highlighted the significant association of MDR1 CC (rs60023214) genotype with complete molecular response. We demonstrate the usefulness of a pharmacogenetic approach for stratifying patients with chronic myeloid leukemia according to their likelihood of achieving a major or complete molecular response to imatinib. This represents an attractive opportunity for therapy optimization, worth testing in clinical trials.
| S-EPMC3561425 | biostudies-literature
Project description:Imatinib is the mainstay of treatment of patients with chronic myeloid leukemia (CML) in Tanzania. Monitoring molecular response to therapy by real-time polymerase chain reaction at defined milestones is necessary for early detection of treatment failure. However, this assay is not routinely performed in Tanzania; therefore, the depth of molecular response among patients with CML is not known. A total of 158 patients with previously diagnosed CML who received imatinib treatment were recruited from January 2019 and followed up through October 2020 at Ocean Road Cancer Institute. Information was obtained at the time of diagnosis and follow-up. Blood samples were collected in EDTA tubes to measure the BCR/ABL ratio on the Gene Xpert system for molecular response determination. The median age of the 158 adult patients was 45 years (range, 18-86). By reference to established treatment milestones, only 37 (23.4%) achieved optimal molecular response. Signs of advanced-stage disease, in particular the need for red cell transfusions before diagnosis (adjusted odds ratio [AOR], 3.4; 95% CI, 1.32-9.17) and cytopenias (AOR, 2.26; 95% CI, 1.03-4.96) necessitating drug interruptions were statistically validated predictors of treatment failure on multivariate, multinomial logistic regression. Patient survival at the 22-month follow-up was lowest, with 78.6% (95% CI, 69.4-85.4) in the failure-to-respond category and highest in patients achieving optimal response 97.0% (95% CI, 80.9-99.6). In summary, the majority of patients with CML treated with imatinib in Tanzania do not obtain deep molecular response. This outcome can be attributed to late diagnosis, the development of cytopenias requiring multiple drug interruptions, and poor adherence to treatment.
| S-EPMC7948290 | biostudies-literature
Project description:Imatinib Mesylate is the drug used for targeted tyrosine kinase inhibition in the beginning of management of all Chronic Myeloid Leukemia (CML) newly diagnosed cases. However, resistance presents a considerable limit to its efficacy. Currently, it is impossible to anticipate IM resistance which makes the recognition of early flags an important treatment goal in CML. In this work we studied the connection between microRNA 30a (miR-30a) and Beclin 1 mediated autophagy and IM resistance in Egyptian CML patients. The study included newly diagnosed (group I, n = 20), imatinib responder (group II, n = 30), imatinib resistant (group III, n = 30) CML patients and a healthy demographically matched control group (group IV, n = 20). miR-30a expression was assayed by quantitative reverse transcription polymerase chain reaction. The variation in expression of miR-30a between CML cases and healthy controls was calculated using relative quantification method (2-ΔΔCT). Beclin 1 was assayed in Peripheral blood mononuclear cells by western blotting. miR-30a was over expressed and Beclin 1 was under expressed in imatinib responders compared to resistant cases median 1.21(0.55-3.02) versus median 0.65 (0.03-1.0) (p = 0.001) and median 950.0 (400.0-2410.0) versus, median 1570.0 (920.0-5430.0) (p < 0.001) respectively. Beclin 1 correlated significantly positively with miR-30a in new cases (p = 0.001) and negatively in imatinib responders (p = 0.021). Receiver Operating Curves demonstrated the performances of miR-30a and Beclin 1 to detect imatinib resistance. They showed sensitivities of 97.14% and 94.29% and specificities of 53.33% and 42.22% at the cut-off values of 1 and 940 respectively. Both miR-30a and Beclin 1 levels showed a relation with imatinib response and can therefore be put forward as valuable markers for detection of resistance and may also have promising future therapeutic implications.
| S-EPMC7326757 | biostudies-literature
Project description:Achieving a deep molecular response (DMR) to tyrosine kinase inhibitor (TKI) therapy for chronic myeloid leukemia (CML) remains challenging and at present, there is no biomarker to predict DMR in this setting. Herein, we report that an HMGCLL1 genetic variant located in 6p12.1 can be used as a predictive genetic biomarker for intrinsic sensitivity to imatinib (IM) therapy. We measured DMR rate according to HMGCLL1 variant in a discovery set of CML patients (n?=?201) and successfully replicated it in a validation set (n?=?270). We also investigated the functional relevance of HMGCLL1 blockade with respect to response to TKI therapy and showed that small interfering RNA mediated blockade of HMGCLL1 isoform 3 results in significant decrease in viability of BCR-ABL1-positive cells including K562, CML-T1 or BaF3 cell lines with or without ABL1 kinase domain mutations such as T315I mutation. Decreased cell viability was also demonstrated in murine CML stem cells and human hematopoietic progenitor cells. RNA sequencing showed that blockade of HMGCLL1 was associated with G0/G1 arrest and the cell cycle. In summary, the HMGCLL1 gene polymorphism is a novel genetic biomarker for intrinsic sensitivity to IM therapy in CML patients that predicts DMR in this setting.
| S-EPMC6756062 | biostudies-literature
Project description:Patched homolog 1 gene (PTCH1) expression and the ratio of PTCH1 to Smoothened (SMO) expression have been proposed as prognostic markers of the response of chronic myeloid leukemia (CML) patients to imatinib. We compared these measurements in a realistic cohort of 101 patients with CML in chronic phase (CP) using a simplified qPCR method, and confirmed the prognostic power of each in a competing risk analysis. Gene expression levels were measured in peripheral blood samples at diagnosis. The PTCH1/SMO ratio did not improve PTCH1 prognostic power (area under the receiver operating characteristic curve 0.71 vs. 0.72). In order to reduce the number of genes to be analyzed, PTCH1 was the selected measurement. High and low PTCH1 expression groups had significantly different cumulative incidences of imatinib failure (IF), which was defined as discontinuation of imatinib due to lack of efficacy (5% vs. 25% at 4 years, P = 0.013), probabilities of achieving a major molecular response (81% vs. 53% at first year, P = 0.02), and proportions of early molecular failure (14% vs. 43%, P = 0.015). Every progression to an advanced phase (n = 3) and CML-related death (n = 2) occurred in the low PTCH1 group (P<0.001 for both comparisons). PTCH1 was an independent prognostic factor for the prediction of IF. We also validated previously published thresholds for PTCH1 expression. Therefore, we confirmed that PTCH1 expression can predict the imatinib response in CML patients in CP by applying a more rigorous statistical analysis. Thus, PTCH1 expression is a promising molecular marker for predicting the imatinib response in CML patients in CP.
| S-EPMC5509313 | biostudies-literature
Project description:Standard first-line therapy of chronic myeloid leukemia is treatment with imatinib. In the randomized German Chronic Myeloid Leukemia-Study IV, more potent BCR-ABL inhibition with 800 mg ('high-dose') imatinib accelerated achievement of a deep molecular remission. However, whether and when a de-escalation of the dose intensity under high-dose imatinib can be safely performed without increasing the risk of losing deep molecular response is unknown. To gain insights into this clinically relevant question, we analyzed the outcome of imatinib dose reductions from 800 mg to 400 mg daily in the Chronic Myeloid Leukemia-Study IV. Of the 422 patients that were randomized to the 800 mg arm, 68 reduced imatinib to 400 mg after they had achieved at least a stable major molecular response. Of these 68 patients, 61 (90%) maintained major molecular remission on imatinib at 400 mg. Five of the seven patients who lost major molecular remission on the imatinib standard dose regained major molecular remission while still on 400 mg imatinib. Only two of 68 patients had to switch to more potent kinase inhibition to regain major molecular remission. Importantly, the lengths of the intervals between imatinib high-dose treatment before and after achieving major molecular remission were associated with the probabilities of maintaining major molecular remission with the standard dose of imatinib. Taken together, the data support the view that a deep molecular remission achieved with high-dose imatinib can be safely maintained with standard dose in most patients. Study protocol registered at clinicaltrials.gov 00055874.
| S-EPMC6518910 | biostudies-literature
Project description:The mechanism of action of imatinib is known to involve the Fas-mediated apoptosis pathway. Consequently inter-individual variations in this apoptosis pathway might be associated with imatinib response or resistance.This study attempted to focus on eight genotypes in the apoptosis pathway including FAS (rs1800682, rs2229521, rs2234767 and rs2234978), FASLG (rs763110), CASP10 (rs13006529), and APAF1 (rs1439123, rs2288713) and analyzed their association with treatment outcomes including molecular response with 4.5 log reduction (MR4.5), following imatinib therapy in 187 Korean CML patients.The GG/GA genotype in FAS (rs2234767) showed a higher rate of MR4.5 than the AA genotype (at 5 years 59.7 vs 37.4 %, p = 0.013). Using a bootstrap procedure for internal validation we confirmed that FAS (rs2234767) correlates with MR4.5 (p = 0.050). Multivariate analysis confirmed that the FAS genotype (rs2234767) is an independent surrogate for MR4.5 (p = 0.019, HR 0.43, 95 % CI [0.22-0.87]).The Fas/FasL signaling pathway may represent the major pathway that mediates apoptosis in CML treated with imatinib. SNP markers in the apoptosis pathway including FAS genotype (rs2234767) can be potential surrogates for predicting deeper molecular response after imatinib therapy.
| S-EPMC4806489 | biostudies-literature
Project description:Imatinib is a tyrosine kinase inhibitor that has revolutionized the treatment of chronic myeloid leukemia (CML). Despite its efficacy, about a third of patients discontinue the treatment due to therapy failure or intolerance. The rational identification of patients less likely to respond to imatinib would be of paramount clinical relevance. We have shown that transmembrane transporter hOCT1 genotyping predicts imatinib activity. In parallel, Polycomb group genes (PcGs) are epigenetic repressors implicated in CML progression and in therapy resistance.We measured the expression of eight PcGs in paired pre- and post-imatinib bone marrow samples from 30 CML patients.BMI1, PHC3, CBX6 and CBX7 expression was significantly increased during imatinib treatment. Post-treatment levels of CBX6 and CBX7 predicted 3-month response rate. Measurement of post-treatment BMI1 levels improved the predictive power of hOCT1 genotyping.These results suggest that the expression levels of PcGs might be useful for a more accurate risk stratification of CML patients.
| S-EPMC5551942 | biostudies-literature
Project description:BACKGROUND:Imatinib mesylate given orally at a daily dose of 400 mg is the standard of care as initial therapy for patients with chronic myeloid leukemia (CML) in chronic phase (CML-CP). Treatment guidelines propose dose escalation based on clinical assessments of disease response. METHODS:Response and survival were analyzed in a cohort of patients (n = 106) with newly diagnosed CML-CP who were enrolled on the International Randomized Study of Interferon and STI571 (IRIS) trial, who began treatment with imatinib at a dose of 400 mg daily, and who subsequently underwent dose escalation to either 600 mg or 800 mg daily. Reasons for dose escalation were evaluated retrospectively based on 2 sets of criteria: the IRIS protocol-defined criteria (n = 39 patients) and the European LeukemiaNet (ELN) recommendations (n = 48 patients). RESULTS:Among all 106 patients who underwent dose escalation, the rates of freedom from progression to accelerated phase or blast phase and overall survival were 89% and 84% at 3 years after dose increase, respectively. A cytogenetic response was obtained in 42% of patients who had their dose escalated based on protocol criteria and in 38% of patients who had their dose escalated according to the ELN recommendations. CONCLUSIONS:The results from this retrospective analysis supported imatinib dose escalation as an appropriate initial option for patients with CML-CP who were experiencing suboptimal cytogenetic response or resistance.
| S-EPMC4445370 | biostudies-literature
Project description:Early molecular response is associated with improved probability of deep molecular response and superior survival in patients with CML-CP. However, ~1 in 3 patients on first-line imatinib do not achieve this threshold. The phase 2b DASCERN trial (NCT01593254) assessed the outcome of early switch to dasatinib in patients with suboptimal response to first-line imatinib. Adult patients with CML-CP were randomized (2:1) to receive 100 mg dasatinib (n = 174) or continue imatinib at ≥400 mg (n = 86). The primary endpoint was the rate of major molecular response (MMR) at 12 months, which was 29% (dasatinib) and 13% (imatinib; P = 0.005). After ≥2 years of follow-up, 45 patients (52%) randomized to continue imatinib had crossed over to dasatinib. Considering treatment crossover, the 2-year cumulative MMR rate was 64% with dasatinib and 41% with imatinib (66% and 67%, respectively by intent-to-treat). Adverse events were consistent with the established safety profiles of both drugs. The results of this first prospective study support early monitoring of patients treated with first-line imatinib, and suggest that switching to dasatinib in cases of suboptimal response may offer clinical benefit. Further follow-up is needed to assess the long-term clinical benefit of early switching.
| S-EPMC7387297 | biostudies-literature