Seven-year follow-up of patients receiving imatinib for the treatment of newly diagnosed chronic myelogenous leukemia by the TARGET system

Changes in chronic myeloid leukemia treatment modalities and outcomes after introduction of second-generation tyrosine kinase inhibitors as first-line therapy: a multi-institutional retrospective study by the CML Cooperative Study Group

This study investigated changes in treatment modalities and outcomes of chronic myeloid leukemia in the chronic phase (CP-CML) after the approval of second-generation tyrosine kinase inhibitors (2G-TKIs) for first-line therapy. Patients were grouped into those who underwent TKI therapy up to December 2010 (imatinib era group, n = 185) and after January 2011 (2G-TKI era group, n = 425). All patients in the imatinib era group were initially treated with imatinib, whereas patients in the 2G-TKI era group were mostly treated with dasatinib (55%) or nilotinib (36%). However, outcomes including progression-free survival, overall survival, and CML-related death (CRD) did not differ significantly between groups. When stratified by risk scores, the prognostic performance of the ELTS score was superior to that of the Sokal score. Even though both scoring systems predicted CRD in the imatinib era, only the ELTS score predicted CRD in the 2G-TKI era. Notably, the outcome of patients classified as high-risk by ELTS score was more favorable in the 2G-TKI era group than in the imatinib era group. Thus, expanding treatment options may have improved patient outcomes in CP-CML, particularly in patients classified as high-risk by ELTS score.

Regulatory T Cell as a Biomarker of Treatment-Free Remission in Patients with Chronic Myeloid Leukemia

Treatment-free remission (TFR) has become a therapeutic goal in chronic myeloid leukemia (CML), and approximately half of the patients with chronic phase-CML (CML-CP) with deep molecular remission (DMR) by tyrosine-kinase inhibitors (TKIs) have achieved TFR. However, the mechanism of continuous TFR is still unclear, as there are "fluctuate" patients who have BCR-ABL-positive leukemia cells but do not observe obvious relapse. We focused on the immune response and conducted an immune analysis using clinical samples from the imatinib discontinuation study, JALSG-STIM213. The results showed that, in the group that maintained TFR for 3 years, changes in regulatory T (Treg) cells were observed early after stopping imatinib treatment. The effector Treg (eTreg) cells increased transiently at 1 month after stopping imatinib and then returned to baseline at 3 months after stopping imatinib treatment. There was no difference in the Treg phenotype, and CD8+ T cells in the TFR group were relatively activated. High concentrations of imatinib before stopping were negatively correlated with eTreg cells after stopping imatinib. These data suggest immunological involvement in the maintenance of the TFR, and that Treg cells after stopping imatinib might be a biomarker for TFR. Furthermore, high imatinib exposure may have a negative immunological impact on the continuous TFR.

Serial evaluation of the pharmacokinetics of ponatinib in patients with CML and Ph + ALL

Although tyrosine kinase inhibitors (TKIs) play a crucial role in the treatment of chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL), intolerance and resistance to TKIs have been serious problems. Due to a lack of research, the importance of the pharmacokinetics (PK) of TKIs is currently unclear. We examined the PK of the third-generation TKI ponatinib to monitor side effects and efficacy during treatments for one patient with CML-chronic phase (CP-CML) and two who received allogeneic hematopoietic stem cell transplantation (allo-HSCT), one for CML-blastic crisis (BC-CML) and one for Ph + ALL. The patient with CP-CML was intolerant to multiple TKIs (dasatinib, nilotinib, imatinib, and bosutinib) and thus was switched to ponatinib (15 mg/day). The patients who received allo-HSCT for BC-CML and Ph + ALL received ponatinib (15 mg/day) as maintenance therapy. Notably, serial evaluation of the PK of ponatinib showed that the median trough values (ng/ml) were 17.2 (12.2-34.5), 33.1 (21.2-40.3) and 27.7 (13.6-29.9) in patients 1, 2, and 3, respectively. These values were around the target concentration (23 ng/ml). All patients are maintaining complete remission without side effects. In conclusion, serial evaluation of PK of ponatinib may yield meaningful information about its safety and efficacy.

Fusion genes as biomarkers in pediatric cancers: A review of the current state and applicability in diagnostics and personalized therapy

The incidence of pediatric cancers is rising steadily across the world, along with the challenges in understanding the molecular mechanisms and devising effective therapeutic strategies. Pediatric cancers are presented with diverse molecular characteristics and more distinct subtypes when compared to adult cancers. Recent studies on the genomic landscape of pediatric cancers using next-generation sequencing (NGS) approaches have redefined this field by providing better subtype characterization and novel actionable targets. Since early identification and personalized treatment strategies influence therapeutic outcomes, survival, and quality of life in pediatric cancer patients, the quest for actionable biomarkers is of great value in this field. Fusion genes that are prevalent and recurrent in several pediatric cancers are ideally suited in this context due to their disease-specific occurrence. In this review, we explore the current status of fusion genes in pediatric cancer subtypes and their use as biomarkers for diagnosis and personalized therapy. We discuss the technological advancements made in recent years in NGS sequencing and their impact on fusion detection algorithms that have revolutionized this field. Finally, we also discuss the advantages of pairing liquid biopsy protocols for fusion detection and their eventual use in diagnosis and treatment monitoring.

The EUTOS long-term survival score predicts disease-specific mortality and molecular responses among patients with chronic myeloid leukemia in a practice-based cohort

The European Treatment and Outcome Study (EUTOS) long‐term survival (ELTS) score predicts disease‐specific death in patients with chronic myeloid leukemia (CML) being treated with imatinib during the chronic phase (CP) of the disease. However, it is unclear whether the ELTS score predicts CML‐related events or treatment responses. This study evaluated the predictive value of the ELTS score regarding prognosis and treatment response in patients with CML‐CP. Clinical data were retrospectively obtained from patients enrolled in the CML Cooperative Study Group (CML‐CSG), which included patients diagnosed with CML‐CP from April 2001 to January 2016, and treated with any tyrosine kinase inhibitor (TKI) as first‐line therapy. Among 342 eligible patients, the ELTS scores indicated low‐, intermediate‐, and high‐risk in 74%, 21%, and 5% of patients, respectively. Patients with high ELTS scores had significantly higher disease‐specific mortality and worse event‐free survival, progression‐free survival, and overall survival. Among four risk scores, including the Sokal, Hasford, EUTOS, and ELTS scores, risk stratification by the ELTS score had the highest predictive value in assessing patient prognosis, and also in treatment responses. In fact, the EUTOS and ELTS scores were able to predict the major molecular response within 12 months. Most importantly, the ELTS score was the only scoring system that predicted deep molecular response at any time, regardless of risk level (65.0%, 43.7%, and 23.5% in low‐, intermediate‐, and high‐risk groups, respectively). Compared to other risk scores, the ELTS score was the most sensitive risk classification tool for the four endpoints of interest in this study, as well as molecular responses in patients with CML‐CP.

Comparison of the clinical outcomes of nilotinib and dasatinib therapies in newly diagnosed patients in the chronic phase of chronic myeloid leukemia: a retrospective analysis

Treatment with a tyrosine kinase inhibitor (TKI) is the standard of care for patients with chronic myeloid leukemia (CML). The new-generation TKIs, nilotinib and dasatinib, are found to have deeper and faster treatment response rates compared to imatinib in the first-line setting. However, a direct comparison between nilotinib and dasatinib has never been reported previously. Our study aims to compare the outcomes and molecular responses achieved following the first-line use of these two agents in patients with CML-CP. The database of the CML Cooperative Study Group was reviewed and patients with CML in the chronic phase (CP) who were given nilotinib or dasatinib as first-line therapy were identified. Out of 361 patients with CML-CP enrolled in our database, 58 and 63 had been treated with conventional doses of nilotinib (300 mg twice daily) and dasatinib (100 mg once daily), respectively, as first-line therapy. The patient demographics did not show significant differences between the groups. The event-free survival rates did not differ between these two groups. The major molecular response (MMR) and the deep molecular response (DMR) rates by 6, 12, 18, and 24 months did not differ between groups. Among the three scoring systems, only the Hasford score could predict the achievement of DMR, and all of them failed to predict the achievement of MMR in the entire cohort. Our data suggest that both nilotinib and dasatinib have comparable efficacies and promising outcomes.

Efficacy and safety of nilotinib therapy in patients with newly diagnosed chronic myeloid leukemia in the chronic phase

ABL1-tyrosine kinase inhibitors (TKIs) have led to dramatic changes in treatment strategies for chronic myeloid leukemia in the chronic phase (CML-CP). However, clinical studies have highlighted increasing numbers of adverse events (AE) with TKIs. Although TKI modification plays a key role in AE management, this process is poorly understood, particularly in terms of the TKI nilotinib. In the present study, we retrospectively analyzed the records of 70 patients with newly diagnosed (ND)-CML-CP who were treated with nilotinib to investigate the drug potency of nilotinib and treatment management. During a median observation period of 3.4 years, 76% of patients continued nilotinib as a first-line treatment. The 1-year and overall major molecular response (MMR) rates and the overall molecular response (MR) 4.5 rate for all patients receiving first-line nilotinib therapy were 70, 84.2, and 50%, respectively. No case progressed to the accelerated or blast phase during the study. To avoid AEs during the early phase, nilotinib doses were reduced to < 600 mg/day in a third of patients (Reduced group); these patients experienced better therapeutic efficacy and a lower rate of AEs relative to those in Standard group (300 mg twice daily). Ten patients who received < 600 mg/day of nilotinib throughout the study had a 1-year MMR rate and overall MR4.5 rate of 90 and 60%, respectively. In summary, our findings indicate that careful management, including dose reduction, can yield better outcomes in patients with ND-CML-CP.

Chronic myeloid leukemia patients in Tunisia: epidemiology and outcome in the imatinib era (a multicentric experience)

Data are limited in developing countries regarding the clinicopathologic features and response to therapy of chronic myeloid leukemia (CML) in the era of imatinib (IM). The objective of this study is to report on the clinicoepidemiologic features of CML in Tunisia, to evaluate the long-term outcome of patients in chronic (CP) or accelerated phase (AP) treated with IM 400 mg daily as frontline therapy, and to determine imatinib's efficacy and safety. From October 2002 to December 2014, 410 CML patients were treated with IM in six Tunisian departments of hematology. Response (hematologic, cytogenetic, and molecular responses) and outcome-overall survival (OS), event-free survival (EFS), and progression-free survival (PFS)-were evaluated. The following prognostic factors were analyzed for their impact on the European leukemia net (ELN) response, OS, EFS, and PFS at 5 years: age, sex, leukocyte count, Sokal score, European Treatment and Outcome Study (EUTOS) score, CML phase, time to starting IM, and impact of adverse events. The median age was 45 years (3-85 years). Two hundred ten (51.2%) patients were male. Splenomegaly was present in 322 of the 410 (79%). Additional cytogenetic abnormalities were encountered in 25 (6.3%) patients. At diagnosis, 379 (92.4%) patients were in CP, 31 (7.6%) were in AP. The Sokal risk was low in 87 (22.5%), intermediate in 138 (35.7%), and high in 164 patients (41.9%). The EUTOS risk was low in 217 (74%), and high in 77 (26%) patients. The rates of cumulative complete cytogenetic response (CCyR), major molecular response (MMR), and molecular response 4/5 log (MR4.5) in CP/AP-CML patients were 72, 68.4, and 46.4%, respectively. The median time to reach CCyR, MMR, and MR4.5 was 6 months (3-51), 18 months (3-72), and 24 months (3-100), respectively. According to the ELN criteria, optimal, suboptimal response, and failure were noted in 206 (51.8%), 61 (15.3%), and 125 (31.4%) patients, respectively. Five-year event-free survival (EFS), progression-free survival (PFS), and overall survival (OS) were 81, 90, and 90%, respectively. By multivariate analysis, AP, high EUTOS risk, and baseline WBC ≥ 150G/l remained independent predictive factors of non-optimal response to IM. The adverse events (AE) of IM were moderate and tolerable. With the caveats that the monitoring of the disease was not optimal, response rates were similar to those reported in previous studies. It is clear to us that improvements should be made in treatment of AP-CML and high Sokal risk group of CP-CML. The frontline use of second-generation tyrosine kinase inhibitor (TKI) is expected to improve the results of the first-line treatment of these high-risk Tunisian patients, but cost and accessibility of this therapy remain the problems in developing countries.

The Efficacy of Reduced-dose Dasatinib as a Subsequent Therapy in Patients with Chronic Myeloid Leukemia in the Chronic Phase: The LD-CML Study of the Kanto CML Study Group

Objective The aim of this study was to prospectively investigate the efficacy and safety profiles of low-dose dasatinib therapy (50 mg once daily). Methods Patients with chronic myeloid leukemia in the chronic phase (CML-CP) who were being treated with low-dose imatinib (≤200 mg/day), but were resistant to this agent were enrolled in the current study (referred to as the LD-CML study). Results There subjects included 9 patients (4 men and 5 women); all were treated with dasatinib at a dose of 50 mg once daily. Among 8 patients who had not experienced major molecular response (MMR; BCR-ABL1 transcript ≤0.1% according to International Scale [IS]) at study enrollment, 5 attained MMR by 12 months. In particular, 3 of 9 patients demonstrated a deep molecular response (DMR; IS ≤0.0069%) by 18 months. Five patients developed lymphocytosis accompanied by cytotoxic lymphocyte predominance. There was no mortality or disease progression, and all continue to receive dasatinib therapy at 18 months with only 2 patients requiring dose reduction. Toxicities were mild-to-moderate, and pleural effusion was observed in 1 patient (grade 1). Conclusion Low-dose dasatinib can attain MMR and DMR without severe toxicity in patients with CML-CP who are unable to achieve MMR with low-dose imatinib. Switching to low-dose dasatinib should therefore be considered for patients in this setting, especially if they are otherwise considering a cessation of treatment.

Deeper molecular response is a predictive factor for treatment-free remission after imatinib discontinuation in patients with chronic phase chronic myeloid leukemia: the JALSG-STIM213 study

The objective of this prospective clinical trial (JALSG-STIM213, UMIN000011971) was to evaluate treatment-free remission (TFR) rates after discontinuation of imatinib in chronic myeloid leukemia (CML). CML patients who received imatinib treatment for at least 3 years and sustained deep molecular response for at least 2 years were eligible. Molecular recurrence was defined as loss of major molecular response (MMR). Of the 68 eligible patients, 38.2% were women, the median age was 55.0 years, and the median duration of imatinib treatment was 97.5 months. The 12-month TFR rate was 67.6%. Patients who lost MMR were immediately treated with imatinib again; all re-achieved MMR. Three-year treatment-free survival (TFS) was estimated as 64.6% using the Kaplan-Meier method. Undetectable molecular residual disease (UMRD) was defined as no BCR-ABL1 in > 100,000 ABL1 control genes using international scale polymerase chain reaction. UMRD at the study baseline was found to be predictive of continuation of TFR. Our findings suggest that CML patients who meet all the eligibility criteria that have commonly been used in the TFR trials are able to discontinue imatinib use safely. TFR may thus be valuable as a new goal for CML treatment in Japan.

Introduction of second-generation tyrosine kinase inhibitors may reduce the prognostic impact of high-risk patients, according to the European treatment and outcome study (EUTOS) score

Our study aims to highlight the critical role of the introduction of second generation tyrosine kinase inhibitors (2nd TKIs) on the prognosis of patients with chronic myeloid leukemia (CML) in chronic phase (CML-CP), as determined by European Treatment and Outcome Study (EUTOS) system. Patients who were diagnosed with CML-CP before March 2009 were classified into the imatinib group, and those diagnosed after April 2009 were classified into the 2nd TKI group. EUTOS high-risk patients exhibited significantly worse outcomes in terms of event-free survival (EFS), progression-free survival (PFS), and CML-associated death than those considered to be low-risk. Risk stratification by EUTOS score was predictive of risk-associated clinical outcomes in patients classified into the imatinib group; however, the EUTOS score failed to predict the outcomes of patients classified into the 2nd TKI group. Our data suggest that the introduction of 2nd TKIs might have improved treatment outcomes, particularly in EUTOS high-risk patients.

Incidences and outcomes of therapy-related chronic myeloid leukemia in the era of tyrosine kinase inhibitors: Surveillance of the CML Cooperative Study Group

This study was performed to investigate the features and outcome of patients with therapy-related chronic myeloid leukemia (TR-CML) who were treated with tyrosine kinase inhibitors (TKIs). The analysis included 308 patients with CML in the chronic phase who were extracted from the CML Cooperative Study Group database. Of these patients, 11 (3.6%) were identified as having TR-CML. No differences in age, sex, white blood cell count, hemoglobin level, platelet count, or European Treatment and Outcome Study risk were observed between patients with TR-CML vs. de novo CML. However, the responses of TR-CML patients to TKIs (6, 3, and 2 received imatinib, nilotinib, and dasatinib, respectively) were excellent; all achieved major or deep molecular response. Furthermore, the outcomes of TR-CML patients were relatively favorable; the 3-year event-free survival rates in the TR-CML and de novo CML patients were 100% and 94%, respectively; the difference was not statistically significant. In conclusion, our study showed that TR-CML patients could achieve a good clinical course with TKI therapy. Detailed investigations of TR-CML may provide new insights into CML biology.

Direct effect of dasatinib on signal transduction pathways associated with a rapid mobilization of cytotoxic lymphocytes

It has been shown that an increase in cytotoxic lymphocyte counts in the peripheral blood occurs rapidly after taking dasatinib, but the underlying mechanism is not yet elucidated. To investigate the influence of dasatinib on signal transduction pathways, we investigated the changes in JAK-STAT, mitogen-activated protein kinase (MAPK), and AKT in cytotoxic lymphocytes, including natural killer (NK) cells and cytotoxic T lymphocytes (CTLs), before and after dasatinib treatment in chronic myeloid leukemia patients. Among a total of 30 patients, 18 were treated with dasatinib, nine with imatinib, and three with nilotinib. At constitutive levels, the expression of phosphorylated proteins, pSTAT1, pSTAT3, and pERK in NK cells and pSTAT3 in CTLs, was significantly higher in dasatinib-treated patients. Among the patients evaluated, only dasatinib-treated patients showed inhibition of multiple signaling pathways after taking a tyrosine kinase inhibitor. The magnitude of pERK and pAKT inhibition was closely associated with an increase in NK cells and CTLs, respectively, after taking a tyrosine kinase inhibitor. Those responses were more evident in patients with cytomegalovirus IgG positivity. In this study, we demonstrated for the first time, the influence of dasatinib on cell events in cytotoxic lymphocytes in vivo and explained the possible underlying mechanism that results in lymphocyte mobilization after dasatinib treatment.

Clinical Features and Treatment Outcomes of 51 Patients with Chronic Myeloid Leukemia Treated with a Tyrosine Kinase Inhibitor at a Single Institution from 2002 to 2014

Although clinical trials of first- and second-generation tyrosine kinase inhibitors (TKIs) have been shown to improve the prognosis of chronic myeloid leukemia (CML), there is still uncertainty about the clinical features, treatment outcomes, adverse effects, and other possible problems of their use in the clinical setting. We retrospectively analyzed 51 CML patients treated with TKIs at a single institution between 2002 and 2014. The patients (median age: 53.8 years) were classified as having chronic (n = 48), accelerated (n = 2), or blastic phase (n = 1) CML. Our treatments included both 1st generation TKIs (60.8%) and 2nd generation TKIs (39.2%). We found that the overall response rates of complete cytogenetic response (CCyR), major molecular response (MMR), and MR4 (molecular response 4) were 90.2%, 78.4%, and 64.7%, respectively. Second line 2nd generation TKIs had response rates equivalent to those of 1st line 1st generation TKIs. Moreover, 1st line 2nd generation TKIs tended to achieve an early response rate. Overall survival (OS) at 5 years was 93.2%. Sudden blastic crisis (BC) occurred in 2 CML patients receiving TKI with CCyR status. Hematopoietic stem cell transplantation was performed for BC (n = 1) and sudden BC (n = 2). Side effects of all grades (1-3) and grade 3 alone were 64.7% and 11.8%, respectively. Dose reduction, replacement with another TKI, or low dose TKI treatment may be useful methods to control side effects. Further reasons of TKI discontinuation were economic problems (n = 3) and pregnancy (n = 1). Consequently, our treatment strategy for CML demonstrated good response rate and OS. Currently, treatment discontinuation due to intolerance, resistance, economic problems, pregnancy, and sudden BC remains a concern in clinical practice.

Oligoclonality and new agent evaluation in acute lymphoblastic leukaemia

New agent development rests on the fundamental assumption that candidate agents or drug combinations that induce objective responses after relapse will prevent relapse, if applied prior to relapse. However, cumulative experience now includes at least 5 examples of interventions with post-relapse objective response rates greater than 50% that failed to improve outcomes when applied prior to relapse. Emerging insights into oligoclonality provide some explanation. In acute lymphoblastic leukaemia, the predominant clones at relapse differ from the predominant clones at presentation. Arguably, the more highly proliferative clones that predominate at relapse differ in drug sensitivity from the less proliferative clones that escape primary therapy. Interventions effective against the predominant clones at relapse may have no effect on the antecedent escapee clones. Response is not sufficient in new agent development. Duration of response has attracted less attention because of variability in post-remission therapy but some patient subsets have such a uniformly dismal outcome that details of post-remission therapy may be irrelevant. Benchmarks are needed. Are recovering blasts members of the same clone or do they represent a new clone? When you eradicate the predominant clones you get a response. When you eradicate all clones, you get a cure.

Association between the concentration of imatinib in bone marrow mononuclear cells, mutation status of ABCB1 and therapeutic response in patients with chronic myelogenous leukemia

Low concentrations of imatinib (IM) in bone marrow cells have been linked with poor prognosis in patients with chronic myeloid leukemia (CML), which may be caused by the emergence of ATP-binding cassette transporter B1 (ABCB1) mutations. The aim of present study was to investigate how clinical outcomes vary among patients with different single nucleotide polymorphisms (SNPs) of ABCB1. A total of 48 adult patients with CML and higher than median ABCB1 mRNA levels were selected for testing of ABCB1 SNPs. In 28 of the 48 patients, the IM concentration and expression levels of human organic cation transporter 1 (hOCT1) and ABCB1 in bone marrow mononuclear cells (BMMCs) were also tested. Correlations between treatment outcomes and IM concentration or the SNP status of ABCB1 were analyzed. Patients were classified by therapeutic response as major molecular response (MMR) (n=11), complete cytogenetic response (CCyR) (n=19) and non-CCyR (n=18) groups. It was found that the concentration of IM in BMMCs of the CCyR group was significant higher than that of the resistant groups (P=0.013). In addition, the IM concentration was positively correlated with the expression of hOCT1 mRNA (R=0.456, P=0.033), but negatively correlated with the expression of ABCB1 mRNA (R=-0.491, P=0.015). Furthermore, the mRNA expression level of ABCB1 was not associated with therapeutic response, but SNPs of the ABCB1 gene were associated with the response to IM. In conclusion, the concentration of IM in BMMCs may be regulated by the ABCB1 gene, and SNPs of the ABCB1 gene predict the therapeutic response to IM in patients with CML.

Early cytotoxic lymphocyte expansion contributes to a deep molecular response to dasatinib in patients with newly diagnosed chronic myeloid leukemia in the chronic phase: results of the D-first study

Dasatinib is one of the key treatment options for chronic myeloid leukemia (CML) patients. Increase in lymphocyte counts has been known to be predictive of a good treatment response under dasatinib treatment as a second line therapy. However, clinical significance of lymphocyte dynamics in the upfront setting has yet to be clarified. To investigate the significance of lymphocyte dynamics in newly diagnosed chronic phase (CP)-CML, patient data of D-First study (ClinicalTrials.gov NCT01464411) were analyzed. Fifty-two CML-CP patients enrolled to this study were treated with dasatinib (100 mg day(-1) ) and all were followed-up for 18 months. The incidence of lymphocyosis was observed in 14 (27%), but it was not associated with deep molecular response achievement. However, natural killer (NK) cell or cytotoxic T lymphocyte (CTL) counts at 1 month were significantly higher in patients with deep molecular response (DMR) by 18 months compared to those without DMR. When the patients were divided into two groups according to those calculated thresholds by receiver operating characteristic curve (407/μL for NK cells and 347/μL for CTLs), the cumulative DMR rates by 18 months were significantly better in higher value group compared to lower value group. In contrast, regulatory T cell counts were significantly lower at 12 and 15 months in patients achieved DMR. These results suggest the presence of dual effects of dasatinib on immune system through the cytotoxic lymphocytes activation and Treg deregulation in different periods in newly diagnosed CML-CP.

Shorter halving time of BCR-ABL1 transcripts is a novel predictor for achievement of molecular responses in newly diagnosed chronic-phase chronic myeloid leukemia treated with dasatinib: Results of the D-first study of Kanto CML study group

To investigate the factors that affect molecular responses on dasatinib treatment in patients with chronic-phase chronic myeloid leukemia (CML-CP), we performed a clinical trial named the "D-First study." Fifty-two patients with newly diagnosed CML-CP were enrolled in this study and received 100 mg dasatinib once daily. A deep molecular response (DMR) was defined as <50 copies/μg RNA of BCR-ABL1 transcript value corrected by GAPDH, which ensures <0.01% of BCR-ABL1 transcript value according to International Scale (BCR-ABL1(IS)). The halving time for BCR-ABL1 transcripts was calculated using transcript levels before dasatinib treatment, transcript levels after 3 months of treatment, and the treatment time between these two points. In terms of molecular response, 38 of 51 (75%) patients reached major molecular response (MMR) by 12 months, and the rate of DMR by 18 months was 59% (30/51). While both BCR-ABL1 transcript levels before treatment and a shorter halving time of BCR-ABL1 transcripts (≤14 days) were significant factors affecting achievement of MMR by 12 months, the Sokal score at diagnosis was not associated with MMR. Importantly, the halving time was the only factor that predicted achievement of DMR by 18 months. We showed that patients with CML-CP treated with dasatinib can be stratified according to the early treatment response as determined by the halving time of BCR-ABL1 transcripts. These data emphasize the significance of the early response from dasatinib treatment in achieving a DMR. (ClinicalTrials.gov; NCT01464411).

The European Treatment and Outcome Study score is associated with clinical outcomes and treatment response following European LeukemiaNet 2013 recommendations in chronic-phase chronic myeloid leukemia

The introduction of tyrosine kinase inhibitors has dramatically improved outcomes for many patients with chronic myeloid leukemia (CML), but some cases are resistant to this treatment. To compare the prognostic performance of Sokal, Hasford, and European Treatment and Outcome Study (EUTOS) scores, patient outcomes and treatment responses were investigated following the European LeukemiaNet (ELN) 2013 recommendations. Seventy-three patients with newly diagnosed chronic-phase CML (CML-CP) treated with any tyrosine kinase inhibitor as initial therapy were analyzed. All scoring systems significantly predicted treatment response at 3 and 6 months; however, only the EUTOS score significantly predicted treatment response at 12 months, following the ELN 2013 recommendations. The 5-year event-free survival rates were 93 and 35 % in the low- and high-risk groups according to the EUTOS score (P < 0.0001). Moreover, the 5-year overall survival rates were 98 and 51 % in the low- and high-risk groups by EUTOS score (P < 0.0001). We suggest that the EUTOS score may provide a better stratification of CML-CP patients for predicting treatment response.

Turkish Chronic Myeloid Leukemia Study: Retrospective Sectional Analysis of CML Patients

Objective: here have been tremendous changes in treatment and follow-up of patients with chronic myeloid leukemia (CML) in the last decade. Especially, regular publication and updating of NCCN and ELN guidelines have provided enermous rationale and base for close monitorization of patients with CML. But, it is stil needed to have registry results retrospectively to evaluate daily CML practices.

Materials and Methods: In this article, we have evaluated 1133 patients’ results with CML in terms of demographical features, disease status, response, resistance and use of second-generation TKIs.

Results: The response rate has been found relatively high in comparison with previously published articles, and we detected that there was a lack of appropriate and adequate molecular response assessment.

Conclusion: We concluded that we need to improve registry systems and increase the availability of molecular response assessment to provide high-quality patient care.

Conflict of interest:None declared.

Deep molecular response in chronic myeloid leukemia: the new goal of therapy?

Chronic myeloid leukemia (CML) is caused by formation of the BCR-ABL1 fusion protein. Tyrosine kinase inhibitors (TKI) that target BCR-ABL1 are now the standard of care for patients with CML. Molecular monitoring of residual BCR-ABL1 mRNA transcripts, typically performed using real-time quantitative PCR, has improved treatment management, particularly for patients with CML in chronic phase. Major molecular response (MMR; i.e., a ≥3-log reduction in BCR-ABL1 transcript levels) is used in current treatment guidelines to assess prognosis. Recent evidence suggests that deeper molecular responses (≥4-log reductions in BCR-ABL1 transcript levels), particularly when attained early during treatment, may have even better correlation with long-term outcomes, including survival and disease progression. Furthermore, achieving deep molecular response is a requirement for entering trials evaluating treatment-free remission (TFR). In this review, we discuss the evolving definition of minimal residual disease and the various levels of molecular response under evaluation in current clinical studies. In addition, the available clinical data on achieving MMR and deeper levels of molecular response with TKI therapy, the prognostic value of deep molecular response, and factors that may predict a patient's ability to achieve and sustain a deep molecular response on TKI therapy are also discussed. Available data from TFR studies are addressed. We discuss current knowledge of the ideal conditions for attempting treatment discontinuation, factors predictive of molecular relapse, when TKI therapy should be restarted, and which therapeutic strategies (when administered in the first-line setting and beyond) are expected to best enable successful TFR.

Imatinib-induced decompensated heart failure in an elderly patient with chronic myeloid leukemia: case report and literature review

Because it is safe and well tolerated, imatinib is a standard first-line therapy for chronic myeloid leukemia (CML). Although there have been sporadic reports of imatinib-induced cardiotoxicity, including left ventricle (LV) dysfunction and heart failure, the evidence for it is contradictory. Here, we reported a case of an 88-year-old male patient with CML developed decompensated heart failure following imatinib therapy. Four days after the initiation of imatinib, the patient developed orthopnea, edema and a pleural effusion accompanied by abdominal distension, nausea and vomiting. The chest X-ray film showed an enlarged cardiac profile. The echocardiogram demonstrated a decreased LV ejection fraction and enlarged left-side cardiac chambers. B-type natriuretic peptide concentrations were markedly increased. The patient recovered soon after the withdrawal of imatinib and introduction of comprehensive therapy for heart failure. Imatinib-induced cardiotoxicity in elderly patients is a potentially serious complication that merits further evaluation.

Complete clearance of Ph+ metaphases after 3 months is a very early indicator of good response to imatinib as front-line treatment in chronic myelogenous leukemia

AIM

To address the incidence and the prognostic role of a very early standard complete cytogenetic response (CCyR) or all Ph- metaphases (MET-, when <20 cells were evaluable).

METHODS

We revised 182 chronic phase chronic myelogenous leukemia patients treated with frontline imatinib (IM) at two institutions from June 2002 to June 2011.

RESULTS

After 3 months of treatment, 138 patients (75.8%) achieved CCyR/MET- while 44 patients (24.2%) still presented Ph+ metaphases (MET+) (<33%, 24 patients; ≥33%, 20 patients). On univariate analysis, palpable spleen enlargement (p < 0.001), WBC count >100.0 × 10(9)/l at onset (p < 0.001), and male gender (p = 0.019) had a negative impact on achievement of CCyR/MET- at 3 months. Among patients with CCyR/MET- after 3 months, there were 15 failures (10.8%) compared to 21 (47.7%) among patients with MET+ (p < 0.001). The 5-year overall survival was 97.0% in patients CCyR/MET- at 3 months and 91.8% in patients MET+ at 3 months (p = 0.277); the 5-year progression-free survival was 88.2% in patients CCyR/MET- at 3 months and 48.4% in patients MET+ at 3 months (p < 0.001).

CONCLUSIONS

The achievement of CCyR/MET- at 3 months seems to have prognostic relevance and could be a very early and useful indicator of an excellent response to IM beyond European LeukemiaNet guidelines.

Development of an effective therapy for chronic myelogenous leukemia

Targeted small-molecule drugs have revolutionized treatment of chronic myeloid leukemia (CML) during the last decade. These agents interrupt a constitutively active BCR-ABL, the causative agent for CML, by interfering with adenosine 5' triphosphate-dependent ABL tyrosine kinase. Although the efficacy of tyrosine kinase inhibitors (TKIs) has resulted in overall survival of greater than 90%, TKIs are not curative. Moreover, no currently approved TKIs are effective against the T315I BCR-ABL variant. However, a new generation of TKIs with activity against T315I is on the horizon. We will highlight the clinical utility of historical CML therapeutics, those used today (first- and second-generation TKIs), and discuss treatment modalities that are under development. Recent advances have illuminated the complexity of CML, especially within the marrow microenvironment. We contend that the key to curing CML will involve strategies beyond targeting BCR-ABL because primitive human CML stem cells are not dependent on BCR-ABL. Ultimately, drug combinations or exploiting synthetic lethality may transform responses into definitive cures for CML.

Comprehensive therapeutic outcomes of frontline imatinib mesylate in newly diagnosed chronic phase chronic myeloid leukemia patients in Korea: feasibility assessment of current ELN recommendation

Optimal responses during imatinib therapy are commonly defined following the European LeukemiaNet (ELN) recommendations. Achievements of these optimal responses have not, however, been comprehensively tested as response-related prognostic factors using single center data sets. We evaluated the parameters using long-term (median 63 months) outcomes from 363 chronic phase chronic myeloid leukemia patients treated with imatinib as frontline therapy at our center. Intention-to-treat analysis showed comparable rates of complete cytogenetic response (86 %), major molecular response (MMR, 54 %), and complete molecular response (MR(4.5), 8 %). Estimated overall survival, progression-free survival, and event-free survival at 7 years were 94, 88 and 84 %, respectively. Achievement of recommended optimal response at 6 months (major cytogenetic response) and 12 months (complete cytogenetic response) yielded significantly better overall, progression-free, and event-free survival. However, achievement of recommended optimal response at 18 months (MMR) provided marginal benefit only in event-free survival. Most ELN criteria were predictive of long-term outcomes, with the exception of the clinical significance of achieving MMR at 18 months. Treatment adherence in the early treatment period was one of the important independent predictors of favorable long-term outcome. Durable cytogenetic and molecular responses were maintained in a majority of patients treated with optimal dose intensity.