Impact of Drug Transporters ABCB1 and ABCG2 and Regulators of Xenobiotic Transport and Metabolism Pxr and CAR Gene Polymorphisms on Clinical Efficacy of Imatinib in Chronic Myeloid Leukemia (CML)

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5222-5222
Author(s):  
Anna Stepien ◽  
Alessandro Martino ◽  
Federico Canzian ◽  
Daniele Campa ◽  
Angelika Stein ◽  
...  
Keyword(s):  
Treatment Outcome ◽  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Drug Transporters ◽  
Pregnane X Receptor ◽  
Imatinib Therapy ◽  
Molecular Response ◽  
Imatinib Treatment ◽  
Primary Resistance ◽  
Allelic Variants

Abstract Background: Inherited background in mechanisms regulating cellular uptake, elimination and metabolism of imatinib and other BCR-ABL tyrosine kinase inhibitors may influence treatment outcome in chronic myeloid leukemia (CML). Despite good efficacy of imatinib in CML therapy, a proportion of patients show suboptimal responses or even primary resistance. Imatinib is a well-established substrate of ABC-superfamily xenobiotic transporters ABCB1 (MDR1, Pg-P) and ABCG2 (BCRP). However, the results of published studies regarding impact of ABCB1 and ABCG2 single nucleotide polymorphisms (SNPs) on imatinib treatment outcome have shown discrepant results. Moreover, little is known on the potential role of polymorphisms of regulators of xenobiotic transport and metabolism, pregnane X receptor (PXR, NR1|2) and constitutive androstane receptor (CAR, NR1|3) in imatinib efficacy. Aim: In this study we verified whether 61 tagging SNPs in drug transporters genes (ABCB1 and ABCG2) and regulators of xenobiotic transport and metabolism gene (PXR and CAR) genes affect imatinib therapy outcomes in CML. Methods: Genotyping was performed in 256 patients of Polish Caucasian origin (141 men and 117 women) treated with imatinib as first line treatment (229; 89.5%) or after second-line after interferon therapy (27; 10.5%). Tagging SNP approach was used to select the genetic variants and resulted in a selection of 61 tagging SNPs including 26 SNPs for ABCB1, 17 SNPs for ABCG2, 11 SNPs for PXR and 7 SNPs for CAR gene. Complete clinical data on imatinib treatment outcome were assessable for analyses of associations with tested SNPs. The influence of SNPs on imatinib outcomes including achievement of complete cytogenetic response (CCyR) at 12 months, achievement of major molecular response (MMR) at 18 months, progression-free survival (PFS), time to treatment failure (TTF) and overall survival (OS) were tested in regard to established clinical and laboratory predictive factors using logistic regression and proportional-hazards regression models. Three inheritance models (co-dominant, dominant and recessive) were tested for all allelic variants. Results: In this study we found that carriers of minor allele of CAR rs4073054A>C SNP significantly associated with shorter TTF on imatinib therapy (OR=2.42, 95%CI 1.41 - 4.17; p=0.0014; Bonferroni corrected p=0.048). In contrast, no impact of other tested allelic variants in ABCB1, ABCG2, PXR and CAR genes on proportion of patients who achieved CCyR at 12 months, MMR at 18 months as well as on probability of PFS, TTF and OS was observed. Conclusion: Our data suggest that inherited variants in the regulator of xenobiotic transport and metabolism CAR gene may modify results of imatinib therapy in CML patients. In contrast, the results of this relatively large study indicate that polymorphic variants in ABCB1, ABCG2 and PXR genes do not seem to play major role as determinants of response to imatinib in CML. Disclosures Robak: MorphoSys AG: Research Funding.

Outcome of Patients with Chronic Myeloid Leukemia Who Recieved an Intermittent Imatinib Therapy.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1034-1034
Author(s):  
Hyun-Gyung Goh ◽  
Soo-Hyun Kim ◽  
Jeong Lee ◽  
Sae-Eun Jang ◽  
Wan-Seok Kim ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Oral Dose ◽  
Median Duration ◽  
Myeloid Leukemia ◽  
Cytogenetic Response ◽  
Imatinib Therapy ◽  
Intermittent Therapy ◽  
Molecular Response ◽  
Imatinib Treatment ◽  
600Mg Daily

Abstract Diagnosis of chronic myeloid leukemia (CML) is based on detection of the BCR-ABL gene or Philadelphia chromosome, and the BCR-ABL tyrosine kinase inhibitor imatinib has been the standard therapy for CML patients. Although imatinib therapy is effective in CML, it is still unclear whether imatinib can be safely discontinued without relapse. This study was designed to investigate the outcome of 26 CML patients after discontinuation of imatinib and to determine whether intermittent imatinib therapy can be employed in CML patients. Between May 2001 and Jun 2007, 555 patients have been treated with imatinib in St Mary’s Hospital of the Catholic University of Korea, and 26 patients discontinued imatinib when they achieved either complete cytogenetic response (CCyR) or complete molecular response (CMR). These 26 patients were diagnosed as Philadelphia positive (Ph+) CML between November 1995 and May 2002, and 22 patients were in chronic phase (CP) and 4 patients were in accelerated phase (AP) at diagnosis. The median age was 35 years (22–56), and 12 patients (46%) were female and 14 (54%) were male. Among 26 patients, 7 received interferon prior to imatinib therapy and 7 underwent SCT. Five patients received both interferon and SCT before imatinib therapy, and the remaining 7 patients received the imatinib as a front line therapy. Imatinib was started at oral dose of 400mg and 600mg daily for patients in CP and AP, respectively, and when they achieved CCyR or CMR, imatinib was discontinued after informed consent of the patient. In case of cytogenetic or molecular relapse, patients in all phases were retreated with imatinib at 400mg daily. Bone marrow (BM) or peripheral blood (PB) samples were obtained at regular intervals from diagnosis for hematologic response (HR), cytogenetic response (CyR) and molecular response (MR) monitorings. Eleven patients discontinued imatinib when they achieved CCyR, and 15 patients discontinued imatinib after achieving CMR. After the median duration of 7 month (4–48) observation without imatinib therapy, hematologic, cytogenetic and molecular relapses occurred in 4, 7 and 10 patients, respectively, and imatinib at oral dose of 400mg daily was reintroduced to all patients except 2 who continued to remain in CMR after imatinib discontinuation. Except 1 patient who expired and 2 patients who are in persistent molecular remission, all of 23 patients are maintaining the best response achieved after imatinib resumption with a median duration of 38 months (16–58). In conclusion, although imatinib cannot be discontinued completely, intermittent therapy can be considered for the treatment of CML patients. Intermittent imatinib treatment should not be restricted to CP patients who achieve CMR, and AP patients or patients with CCyR also can be considered for intermittent imatinib treatment. We will continue the follow-up of the patients enrolled in this study, and long-term study of intermittent imatinib treatment with expanded pool of patients will enable us to determine the accurate consequences of discontinuation of imatinib and intermittent imatinib treatment.

The Impact of Cytogenetic Response At 6 Months of Therapy in Global Survival of Patients with Chronic Myeloid Leukemia Treated with Imatinib in the South of Brazil

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4453-4453
Author(s):  
Laura Fogliatto ◽  
Marcelo Capra ◽  
Mariza Schaan ◽  
Mario Sérgio Fernandes ◽  
Tito Vanelli Costa ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Cytogenetic Response ◽  
Imatinib Therapy ◽  
Molecular Response ◽  
Imatinib Treatment ◽  
Major Molecular Response ◽  
Global Survival ◽  
The Impact

Abstract Abstract 4453 Background Treatment of chronic myeloid leukemia with imatinib leads to disease remission in a majority of patient, but in some patients (pts) controlling the disease remains a challenge. One of the proposed prognostic factors for identifying this subset of pts is the treatment response in the first months of therapy. Objectives We conducted a study to evaluate the importance of the early complete cytogenetic response (CCyR) and the factors associated with its achievement. Methods This is a retrospective study in a cohort of pts with chronic-phase chronic myeloid leukemia (CP-CML) enrolled in 3 Hematology centers in South Brazil. All pts received imatinib 400mg as first or second-line therapy. Early-imatinib treatment was considered when imatinib started before 12 months (mo) from diagnosis. Patient evaluation and response criteria followed the ELN recommendations. The ACE-27 (Adult Comorbidity Evaluation-27) is a 27 item comorbidity index for patients with cancer and assign weights from 1 to 3 based on the dysfunction grade of each condition (mild, moderate and severe, respectively). An ACE-27 score was applied to each patient. Imatinib suspensions were considered if superior to 20 days at any point during therapy. Global survival (GS) was measured from the start of imatinib to the date of death from any cause. Results We analyzed data from 181 pts with CP-CML diagnosed since 1990. The median age at diagnosis was 48 yr (4 – 85) and 55% were male. The median time from diagnosis to imatinib was 7 mo (0 – 178) and 71% pts were early-imatinib treated. Prior therapy with interferon was used in 60% pts. The median of follow-up was 47 mo. With 6 months of imatinib therapy, 123 pts (68%) achieved CCyR, in this group the four year global survival was 97%. 58 (32%) were not in CCyR at 6 months of therapy, in this group the four year GS was 87%. This difference was significant (P=.024; Figure 1). The chance of achieving major molecular response (MMR) during follow up was 79% for the pts with CCyR at 6 months compared to 53% for the group with no CCyR at 6 months (P<0,001). Some factors were associated with reduced chance of CCyR at 6 months. In a multivariate analysis, the pts with late-onset imatinib treatment (more than 12 mo from diagnosis) had a CCyR rate of 31%, in contrast, the pts who started imatinib before 12 mo had a rate of 50% (P=0,02). The pts with good adherence to treatment had greater CCyR rate than those with poor adherence (interruption greater than 20 days), 51,4% and 35%, respectively (P=0,04). Comorbidity measured by ACE-27 score also influenced the CCyR rates at 6 months: 54% of score 0 (no comorbidity) patients achieved CCyR, compared to 30% of pts with score 1 (mild comorbidity), 33% of pts with score 2 (moderate) and 47% of pts with score 3 (severe) (P=0,009). The greater CCyR rate in the severe comorbidity group probably lacks significance due to the reduced number of pts in this group (22). Conclusions A great proportion of pts achieve CCyR after 6 months of imatinib therapy, nevertheless, the pts who achieve CCyR by 6 months of therapy have greater proportion of major molecular response and global survival. Imatinib therapy should be started as soon as possible and additional efforts must be taken to avoid nonadherence. Finally, special attention should be given to pts with comorbidities as their results tend to be worse. Disclosures: No relevant conflicts of interest to declare.

The Role of Early Cytogenetic Response in Patients with Chronic Myeloid Leukemia Treated with Imatinib and the Impact of Adherence and Comorbidities

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4423-4423
Author(s):  
Laura Fogliatto ◽  
Marcelo Capra ◽  
Mariza Shaan ◽  
Tito Vanelli Costa ◽  
Mayde Seadi Torriani ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Median Time ◽  
Myeloid Leukemia ◽  
Cytogenetic Response ◽  
Imatinib Therapy ◽  
Molecular Response ◽  
Imatinib Treatment ◽  
Major Molecular Response ◽  
Complete Cytogenetic Response

Abstract Abstract 4423 Background Treatment of chronic myeloid leukemia with imatinib leads to disease remission in a majority of patient, but in some patients (pts) controlling the disease remains a challenge. One of the proposed prognostic factors for identifying this subset of pts is the treatment response in the first months of therapy. Objectives We conducted a study to evaluate the importance of the early complete cytogenetic response (CCyR) and the factors associated with its achievement. Methods This is a retrospective study in a cohort of pts with chronic-phase chronic myeloid leukemia (CP-CML) enrolled in 14 Hematology centers in South Brazil. All pts received imatinib 400mg as first or second-line therapy. Early-imatinib treatment was considered when imatinib started before 12 months (mo) from diagnosis. Patient evaluation and response criteria followed the ELN recommendations. The ACE-27 (Adult Comorbidity Evaluation-27) is a 27 item comorbidity index for patients with cancer and assign weights from 1 to 3 based on the dysfunction grade of each condition (mild, moderate and severe, respectively). An ACE-27 score was applied to each patient. Imatinib suspensions were considered if superior to 20 days at any point during therapy. EFS was measured from the start of imatinib to the date of any of the following events while on therapy: death from any cause, loss of complete hematologic response, loss of complete cytogenetic response, discontinuation of therapy for toxicity or lack of efficacy, or progression to accelerated phase or blastic phase. Results We analyzed data from 450 pts with CP-CML diagnosed since 1990. The median age at diagnosis was 48 yr (4 – 85) and 55% were male. The median time from diagnosis to imatinib was 7 mo (0 – 178) and 71% pts were early-imatinib treated. Prior therapy with interferon was used in 60% pts. The median of follow-up was 47 mo. With 6 months of imatinib therapy, 198 pts (44%) achieved CCyR. In this group, the four year cumulative incidence of events was 33 (17%) and the EFS was 75,5%. 252 (56%) were not in CCyR at 6 months of therapy. In this group, a greater proportion of cumulative of events was observed: 86 (34%), and the EFS was 62,3%. This difference was significant (P=0,03; Figure 1). In this group of pts, 63% achieved CCyR after 6 months any time during follow up and the median time for CCyR in these pts was 17 months. The chance of achieving major molecular response (MMR) during follow up was 79% for the pts with CCyR at 6 months compared to 53% for the group with no CCyR at 6 months (P<0,001). Some factors were associated with reduced chance of CCyR at 6 months. In a multivariate analysis, the pts with late-onset imatinib treatment (more than 12 mo from diagnosis) had a CCyR rate of 31%, in contrast, the pts who started imatinib before 12 mo had a rate of 50% (P=0,02). The pts with good adherence to treatment had greater CCyR rate than those with poor adherence (interruption greater than 20 days), 51,4% and 35%, respectively (P=0,04). Comorbidity measured by ACE-27 score also influenced the CCyR rates at 6 months: 54% of score 0 (no comorbidity) patients achieved CCyR, compared to 30% of pts with score 1 (mild comorbidity), 33% of pts with score 2 (moderate) and 47% of pts with score 3 (severe) (P=0,009). The greater CCyR rate in the severe comorbidity group probably lacks significance due to the reduced number of pts in this group (22). Conclusions A great proportion of pts achieve CCyR after 6 months of imatinib therapy, nevertheless, the pts who achieve CCyR by 6 months of therapy have greater proportion of major molecular response and event-free survival. Imatinib therapy should be started as soon as possible and additional efforts must be taken to avoid nonadherence. Finally, special attention should be given to pts with comorbidities as their results tend to be worse. Disclosures: No relevant conflicts of interest to declare.

Characteristics of BCR/ABL1 kinase domain mutations in the patients with chronic myeloid leukemia who are primary resistant to the imatinib therapy

2019 ◽  
Vol 11 (1) ◽  
pp. 27-33
Author(s):  
I Dmytrenko ◽  
J Minchenko ◽  
I Dyagil
Keyword(s):  
Overall Survival ◽  
Chronic Myeloid Leukemia ◽  
Tyrosine Kinase ◽  
Myeloid Leukemia ◽  
High Efficiency ◽  
Kinase Domain ◽  
Imatinib Therapy ◽  
Missense Mutations ◽  
Primary Resistance ◽  
Kinase Domain Mutations

The chronic myeloid leukemia (CML) development is associated with the formation of the BCR/ABL1 fusion gene and the BCR/ABL1 protein with increased tyrosine kinase activity. Despite the high efficiency of targeted therapy, up to 30% of patients do not respond on such therapy i.e. are primary resistant. The presence of BCR/ABL1 kinase domain mutations is considered to be one of the reasons of tyrosin kinase inhibitors resistance. To evaluate the frequency of BCR/ABL1 kinase domain mutations in Ukrainian cohort of CML patients with primary resistance to imatinib therapy, we retrospectively studied BCR/ABL1 kinase domain mutations in peripheral blood of 107 CML patients. The nucleotide sequence was determined by direct sequencing by Sanger. Mutations were reported in 45 of 107 (41.7%) CML patients. Two mutations at a time were revealed in 8 patients. So a total of 53 mutations were found out. Among them 49 were missense-mutations and 4 - deletions of different regions of the BCR/ABL1 kinase domain gene. The missense-mutations F359I/V (12 patients), T315I (8 patients) and G250E (6 patients) were most common. By localization, the mutations majority (23 of 53) was in the P-loop, 10 mutations - in the contact site, 13 mutations - in the catalytic domain and 6 – in the A-loop. Of the detected mutations, 26 (49%) resulted in a disruption of the hydrogen bond between BCR/ABL1-tyrosine kinase and imatinib. Significant reduction in overall survival was found in patients with BCR/ABL1 kinase domain mutations compared with patients with wild-type of BCR/ABL1 gene (p=0.018). The estimated 3-year overall survival was 83.4% (95% CI: 77.0%-89.8%) and 94.3% (95% CI: 91.0%-97.3%), respectively. Therefore, mutations of the BCR/ABL1 kinase domain are one of the mechanisms of primary resistance in CML patients on imatinib therapy. The occurrence of BCR/ABL1 gene mutations impairs the prognosis of imatinib therapy response.

Analyses of Treatment Outcome According to Age in Patients With Chronic Myeloid Leukemia Receiving Front-line Imatinib Therapy

2017 ◽  
Vol 17 (10) ◽  
pp. 696-702
Author(s):  
Irena Ćojbašić ◽  
Lana Mačukanović-Golubović ◽  
Miodrag Vučić ◽  
Ivan Tijanić
Keyword(s):  
Treatment Outcome ◽  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Imatinib Therapy ◽  
Front Line

scholarly journals The Role of Monitoring the Bcr-Abl Transcript Levels in the Management of Patients with Chronic Myeloid Leukemia

2013 ◽  
Vol 59 (2) ◽  
pp. 71-74
Author(s):  
Aliz-Beáta Tunyogi ◽  
I Benedek ◽  
Judit Beáta Köpeczi ◽  
Erzsébet Benedek ◽  
Enikő Kakucs ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Kinase Inhibitors ◽  
Blast Crisis ◽  
Chronic Gvhd ◽  
Molecular Response ◽  
Imatinib Treatment ◽  
Molecular Monitoring ◽  
Hematopoietic Stem ◽  
Transcript Levels

Abstract Introduction: Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder; the molecular hallmark of the disease is the BCR-ABL gene rearrangement, which usually occurs as the result of a reciprocal translocation between chromosomes 9 and 22. Tyrosine kinase inhibitors (TKI) were the first drugs that targeted the constitutively active BCR-ABL kinase and it have become the standard frontline therapy for CML. Monitoring the treatment of CML patients with detection of bcr-abl transcript levels with real time qualitative polymerase chain reaction (RQ-PCR) is essential in evaluating the therapeutic response. Material and method: At the Clinical Hematology and BMT Unit Tîrgu Mureș, between 2008-2011, we performed the molecular monitoring of bcr-abl transcript levels with RQ-PCR in 16 patients diagnosed with CML. Results: We have 11 patients on imatinib treatment who achieved major molecular response. One patient lost the complete molecular response after 5 years of treatment. Two patients in blast crisis underwent allogeneic hematopoietic stem cell transplantation from identical sibling donors. The first patient is in complete molecular remission after 4 years of the transplant with mild chronic GVHD. The other patient had an early relapse with treatment refractory disease and died from evolution of the disease. Three patients with advanced phases of the disease present increasing transcript levels. We performed the dose escalation, and for two of them the switch to the second generation of TKI. Conclusions: Regular molecular monitoring of individual patients with CML is clearly desirable. It allows for a reassessment of the therapeutic strategy in cases of rising levels of BCR-ABL as an early indication of loss of response.

scholarly journals European Treatment and Outcome Study (Eutos) Score Predicts Early Molecular Response to Imatinib Therapy in Chronic Phase Chronic Myeloid Leukemia Patients (Cp-Cml)

2014 ◽  
Vol 25 ◽  
pp. iv337
Author(s):  
K. Sudheer Reddy ◽  
M. Manickavasagam ◽  
V. Venkata Sampath ◽  
D. Barghavi ◽  
A. Vindhyavasini ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Chronic Phase ◽  
Imatinib Therapy ◽  
Molecular Response ◽  
Outcome Study ◽  
Eutos Score

Long Term Adherence to Imatinib Therapy Is the Critical Factor for Achieving Molecular Responses in Chronic Myeloid Leukemia Patients.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3290-3290 ◽  
Author(s):  
Alex Bazeos ◽  
Jamshid Khorashad ◽  
François-Xavier Mahon ◽  
Lina L Eliasson ◽  
Dragana Milojkovic ◽  
...  
Keyword(s):  
Chronic Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Research Funding ◽  
Independent Predictor ◽  
Chronic Phase ◽  
Imatinib Therapy ◽  
Adherence Rate ◽  
Molecular Response ◽  
Molecular Responses ◽  
Adherence To Therapy

Abstract Abstract 3290 Poster Board III-1 There is a great variability in the degree of molecular responses achieved by chronic myeloid leukemia (CML) patients treated with imatinib. These different levels of molecular response could reflect different degrees of adherence to therapy. We measured the adherence to imatinib therapy in 87 consecutive CML chronic phase patients who had received imatinib 400 mg day as first line therapy for a median of 59.7 months before enrolment (range 25–104) and therefore all them were in complete cytogenetic response. Adherence levels were monitored during a 3-month period using microelectronic monitoring devices (MEMS) and were related to levels of molecular response. MEMS consist of an electronic device fitted in the cap of a normal looking medication bottle that automatically records each time the bottle is opened. MEMS are considered as the ‘gold standard' for measuring adherence. We also measured the imatinib plasma level, the presence of TKD mutations and the following prognostic factors measured at diagnosis: hOCT1 transcripts level, polymorphism 1236C&gt;T in ABCB1, Sokal risk group, hemoglobin, leukocytes , BCR-ABL1 transcript type and BCR1-ABL1 ratio and demographic data. The study protocol was approved by the Research Ethics Committee and patients gave written informed consent to participate. The median adherence rate was 97.6% (range 22.6–103.8%). In 23 (26.4%) patients adherence was ≤90% (median 76%) and in 12 (13.8%) ≤80% (median 63%). We found a strong association between adherence rate (≤90% or &gt;90%) and the 6-year probability of major molecular response (MMR) (28.4% vs 94.5%, p&lt;0.0001) and complete molecular response (CMR) (0% vs 43.8%, p=0.002) (Fig 1). Multivariate analysis identified adherence (RR=11.7, p=0.001) and expression of the molecular transporter hOCT1, (RR=1.79, p=0.038) as the only independent predictors for MMR. Adherence was the sole independent predictor for CMR. No molecular responses were observed when the adherence was ≤20% (p=0.0001). In patients whose imatinib dose had been increased (n=32) the adherence was poor (median 86.4%). Adherence was the only independent predictor for failure to achieve a 3-log transcript reduction (RR=17.66, p=0.006) in this subgroup of patients. Patients with CML vary greatly in their response, as demonstrated originally by Sokal et al. in 1984, and the same variation is seen in patients treated with imatinib in the modern era. The basis for this variation is unknown but it has been attributed to the intrinsic biological heterogeneity of the leukemia. In contrast we show here that adherence to therapy is the major factor determining the degree of response that a CML patient treated with imatinib will achieve. Disclosures: Mahon: Novartis: Consultancy, Research Funding. Apperley:Novartis: Consultancy, Honoraria. Rezvani:Novartis: Consultancy, Honoraria, Research Funding. Marin:Novartis: Consultancy, Research Funding.

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