Germ line DDX41 mutations define a unique subtype of myeloid neoplasms.

Germ line DDX41 variants have been implicated in late-onset myeloid neoplasms (MNs). Despite an increasing number of publications, many important features of DDX41-mutated MNs remain to be elucidated. Here we performed a comprehensive characterization of DDX41-mutated MNs, enrolling a total of 346 patients with DDX41 pathogenic/likely-pathogenic (P/LP) germ line variants and/or somatic mutations from 9082 MN patients, together with 525 first-degree relatives of DDX41-mutated and wild-type (WT) patients. P/LP DDX41 germ line variants explained ∼80% of known germ line predisposition to MNs in adults. These risk variants were 10-fold more enriched in Japanese MN cases (n = 4461) compared with the general population of Japan (n = 20 238). This enrichment of DDX41 risk alleles was much more prominent in male than female (20.7 vs 5.0). P/LP DDX41 variants conferred a large risk of developing MNs, which was negligible until 40 years of age but rapidly increased to 49% by 90 years of age. Patients with myelodysplastic syndromes (MDS) along with a DDX41-mutation rapidly progressed to acute myeloid leukemia (AML), which was however, confined to those having truncating variants. Comutation patterns at diagnosis and at progression to AML were substantially different between DDX41-mutated and WT cases, in which none of the comutations affected clinical outcomes. Even TP53 mutations made no exceptions and their dismal effect, including multihit allelic status, on survival was almost completely mitigated by the presence of DDX41 mutations. Finally, outcomes were not affected by the conventional risk stratifications including the revised/molecular International Prognostic Scoring System. Our findings establish that MDS with DDX41-mutation defines a unique subtype of MNs that is distinct from other MNs.

Long-term follow-up after R-High CHOP/CHASER/LEED with Auto-PBSCT in untreated mantle cell lymphoma-Final analysis of JCOG0406.

Progression-free survival after R-High CHOP/CHASER/LEED with auto-PBSCT in untreated mantle cell lymphoma in JCOG0406 study. A continuous pattern of relapse was observed.

Copanlisib, a novel phosphoinositide 3-kinase inhibitor, combined with carfilzomib inhibits multiple myeloma cell proliferation.

Multiple myeloma (MM) is a uniformly fatal disorder of B cells characterized by the accumulation of abnormal plasma cells. Phosphoinositide 3-kinase (PI3K) signaling pathways play a critical regulatory role in MM pathology. Copanlisib, also known as BAY80-6946, is a potent PI3Kα and δ inhibitor. In this study, we investigated the efficacy of copanlisib and a proteasome inhibitor using MM cell lines and primary samples. The p110α and δ catalytic subunits of the class PI3K increased, and carfilzomib activity reduced in the presence of a supernatant from the feeder cell line, HS-5. Phosphorylation of Akt and activation of caspase 3 and poly (ADP-ribose) polymerase (PARP) partially reduced upon carfilzomib treatment in the presence of HS-5. Apoptosis also decreased. Copanlisib treatment for 72 h inhibited growth in MM cell lines and induced apoptosis. Combination treatment of MM cells with carfilzomib and copanlisib caused greater cytotoxicity than that caused by either drug alone and increased apoptosis. Caspase 3 activity increased while that of Akt decreased after combination treatment with copanlisib and carfilzomib. Further, copanlisib inhibited vascular endothelial growth factor (VEGF)-mediated angiogenesis in vitro and in vivo. It also inhibited C-X-C motif chemokine 12 (CXCL12)-mediated chemotaxis. The data suggest that administration of the PI3K inhibitor, copanlisib, may be a powerful strategy against stroma-associated drug resistance of MM cells and can enhance the cytotoxic effects of proteasome inhibitors in such residual MM cells.

Clonal architecture in patients with myelodysplastic syndromes and double or minor complex abnormalities: Detailed analysis of clonal composition, involved abnormalities, and prognostic significance.

The study analyzes the clonal architecture and the abnormalities involved in a series of 191 patients with myelodysplastic syndromes (MDS) and 2-3 clonal abnormalities. All patients were extracted from an international database. The patients were classified into six clonal subtypes (2A-3C) based on the number of abnormalities and the presentation of unrelated clones (UC) and/or a clonal evolution. UC were detected in 23/191 patients (12%). The composition of UC showed great variability. The only recurrent combination of abnormalities was del(5q) and + 8 in 8 of 23 patients (35%). In patients with clonal evolution, the clone size of the primary and secondary clone varied: Patients with -7 and + 8 in the primary clone showed a larger primary and a smaller secondary clone (-7: median 74% vs 10%; +8 73% vs 18%) while patients with del(5q) in the primary clone showed a smaller primary and a larger secondary clone (33% vs 61%). Univariate and multivariate analyses showed no significant differences regarding overall or AML-free survival between the clonal subtypes. Only the subtype 3C (3 abnormalities and clonal evolution) was an independent risk factor for developing AML (Hazard Ratio 5.5 as compared to subtype 2A, P < .05). Finally, our study confirms that the number of abnormalities clearly defines a significant risk factor for overall- as well as AML-free survival. Importantly, in patients with more than one clone, the calculation of the number of abnormalities in the entire sample instead of the number of abnormalities per clone allows a higher prognostic accuracy.

R-High-CHOP/CHASER/LEED with autologous stem cell transplantation in newly diagnosed mantle cell lymphoma: JCOG0406 STUDY.

Although induction immunochemotherapy including high-dose cytarabine and rituximab followed by high-dose chemotherapy (HDC) with autologous stem cell transplantation (ASCT) is recommended for younger patients (≤65 years old) with untreated mantle cell lymphoma (MCL), no standard induction and HDC regimen has been established. We conducted a phase II study of induction immunochemotherapy of R-High-CHOP/CHASER followed by HDC of LEED with ASCT in younger patients with untreated advanced MCL. Eligibility criteria included untreated MCL, stage II bulky to IV, and age 20-65 years. Patients received 1 cycle of R-High-CHOP followed by 3 cycles of CHASER every 3 weeks. Peripheral blood stem cells (PBSC) were harvested during CHASER. LEED with ASCT was delivered to patients who responded to R-High-CHOP/CHASER. Primary endpoint was 2-year progression-free survival (PFS). From June 2008 to June 2012, 45 patients (median age 59 years; range 38-65 years) were enrolled. PBSC were successfully harvested from 36 of 43 patients. Thirty-five patients completed ASCT. Two-year PFS was 77% (80% CI 68-84), which met the primary endpoint. Five-year PFS and overall survival were 52% (95% CI 34-68%) and 71% (95% CI 51-84%), respectively. Overall response and complete response rates after induction immunochemotherapy were 96% and 82%, respectively. The most common grade 4 toxicities were hematological. In younger patients with untreated MCL, R-High-CHOP/CHASER/LEED with ASCT showed high efficacy and acceptable toxicity, and it can now be considered a standard treatment option.

Exosomal miRNA Signatures for Late-Onset Acute Graft-Versus-Host Disease in Allogenic Hematopoietic Stem Cell Transplantation.

Recent studies have demonstrated that exosomal microRNAs (miRNAs) have the potential of facilitating molecular diagnosis. Currently, little is known about the underlying mechanism behind late-onset acute graft-versus-host disease (LA GVHD). Identifying differentially expressed miRNAs in exosomes should be useful for understanding the role of miRNAs in this disease. This study was established to investigate the relevance of miRNAs in exosomes derived from patients developing LA GVHD after allogeneic hematopoietic stem cell transplantation (HSCT). Plasma samples were collected from patients with LA GVHD (n = 5), non-GVHD (n = 5), and controls (n = 8) for exosomal miRNA expression profiling using a TaqMan low-density array; the results were validated by quantitative reverse transcription polymerase chain reaction (RT-PCR). We analyzed exosomal miRNAs differentially expressed among these three groups. MirTarBase was employed to predict potential target genes of the miRNAs specific for LA GVHD. We detected 55 miRNAs that were differentially expressed with a significant change >2.0-fold between LA GVHD and non-GVHD. Of these, we selected the 10 miRNAs (miR-423-5p, miR-19a, miR-142-3p, miR-128, miR-193b, miR-30c, miR-193a, miR-191, miR-125b, and miR-574-3p) with the most significant differential expression. Using quantitative RT-PCR, we further identified that miR-128 was significantly upregulated at the onset of LA GVHD compared with that in normal controls and is a promising diagnostic marker of LA GVHD, with an area under the curve (AUC) value of 0.975. MirTarBase analysis revealed that the predicted target genes of miR-128 are involved in the immune system and inflammation. Increased expression of miR-128 may serve as a novel, noninvasive biomarker for early LA GVHD diagnosis.

[Human herpesvirus-6 pneumonitis following autologous peripheral blood stem cell transplantation].

A-46-year-old man was diagnosed with peripheral T cell lymphoma, not otherwise specified. He achieved a complete remission after pirarubicin, cyclophosphamide, vincristine, and prednisolone (THP-COP) therapy and successful autologous peripheral blood stem-cell transplantation (AutoSCT). However, 6 months post AutoSCT, he complained of fever. Chest computed tomography of the patient displayed bilateral interstitial pneumonitis. Human herpesvirus-6 (HHV-6) DNA was detected in his bronchoalveolar lavage fluid. Therefore, the patient was confirmed for HHV-6 pneumonitis. The treatment with foscarnet was effective, and no relapse was noticed in the patient. Besides, we have experienced pneumonitis of unknown origin in some patients after autologous or allogeneic stem-cell transplantations. Moreover, most of the above patients were clinically diagnosed using serum or plasma markers. Therefore, examining respiratory symptoms after AutoSCT would enable a more accurate diagnosis as well as treatment of patients with HHV-6 pneumonitis.

Phase 1/2 study of the WT1 peptide cancer vaccine WT4869 in patients with myelodysplastic syndrome.

WT4869 is a synthetic peptide vaccine derived from the Wilms' tumor gene 1 (WT1) protein. This phase 1/2 open-label study evaluated the safety and efficacy of WT4869, and biomarkers for response, in patients with myelodysplastic syndrome. WT4869 (5-1200 µg/dose) was administered intradermally every 2 weeks, according to a 3 + 3 dose-escalation method in higher-risk (International Prognostic Scoring System score ≥1.5) or lower-risk (score <1.5) red blood cell transfusion-dependent patients with myelodysplastic syndrome. Twenty-six patients were enrolled and treated (median age, 75 years; range, 32 to 89). The most common adverse event was injection site reaction (61.5%). Main grade 3 or 4 adverse events were neutropenia (30.8%), febrile neutropenia, pneumonia, elevated blood creatine phosphokinase levels and hypoalbuminemia (all 7.7%). Dose-limiting toxicities occurred in 1 patient in the 50 µg/dose cohort (pyrexia, muscle hemorrhage and hypoalbuminemia) and 1 patient in the 400 µg/dose cohort (pneumonitis); however, the maximum tolerated dose could not be determined from this trial. The overall response rate was 18.2%, the disease control rate was 59.1% and median overall survival was 64.71 weeks (95% confidence interval: 50.29, 142.86) as assessed by the Kaplan-Meier method. Subgroup analysis of azacitidine-refractory patients with higher-risk myelodysplastic syndrome (11 patients) showed median overall survival of 55.71 weeks (approximately 13 months). WT1-specific cytotoxic T lymphocyte induction was observed in 11 of 25 evaluable patients. WT4869 was well tolerated in patients with myelodysplastic syndrome and preliminary data suggest that WT4869 is efficacious. This trial was registered at www.clinicaltrials.jp as JapicCTI-101374.

Genetic variants in C5 and poor response to eculizumab.

BACKGROUND: Eculizumab is a humanized monoclonal antibody that targets complement protein C5 and inhibits terminal complement-mediated hemolysis associated with paroxysmal nocturnal hemoglobinuria (PNH). The molecular basis for the poor response to eculizumab in a small population of Japanese patients is unclear. METHODS: We assessed the sequences of the gene encoding C5 in patients with PNH who had either a good or poor response to eculizumab. We also evaluated the functional properties of C5 as it was encoded in these patients. RESULTS: Of 345 Japanese patients with PNH who received eculizumab, 11 patients had a poor response. All 11 had a single missense C5 heterozygous mutation, c.2654G → A, which predicts the polymorphism p.Arg885His. The prevalence of this mutation among the patients with PNH (3.2%) was similar to that among healthy Japanese persons (3.5%). This polymorphism was also identified in a Han Chinese population. A patient in Argentina of Asian ancestry who had a poor response had a very similar mutation, c.2653C → T, which predicts p.Arg885Cys. Nonmutant and mutant C5 both caused hemolysis in vitro, but only nonmutant C5 bound to and was blocked by eculizumab. In vitro hemolysis due to nonmutant and mutant C5 was completely blocked with the use of N19-8, a monoclonal antibody that binds to a different site on C5 than does eculizumab. CONCLUSIONS: The functional capacity of C5 variants with mutations at Arg885, together with their failure to undergo blockade by eculizumab, account for the poor response to this agent in patients who carry these mutations. (Funded by Alexion Pharmaceuticals and the Ministry of Health, Labor, and Welfare of Japan.).

BCR-ABL1-positive chronic myeloid leukemia emerging in a patient with secondary myelofibrosis harboring the JAK2-V617F mutation.

A 53-year-old woman with a 27-year history of myeloproliferative neoplasms came to our hospital because of a marked white blood cell count increase and progressive anemia. Clinical examination demonstrated positivity for BCR-ABL1 and JAK2-V617F mutations. She was given a diagnosis of chronic myeloid leukemia. Using the international scale, a molecular response (MR) 4.5 was achieved after treatment with dasatinib, despite the persistence of marked splenomegaly. The pathological findings of myelofibrosis were demonstrated by bone marrow biopsy. After stopping dasatinib administration for 4 years and 5 months, treatment with ruxolitinib was started. Five months later, the size of her spleen was reduced. We speculated that translocation of BCR-ABL1 might have occurred in a sub-clone of the JAK2-V617F mutated tumor clone.

Exosomes promote bone marrow angiogenesis in hematologic neoplasia: the role of hypoxia.

PURPOSE OF REVIEW: To review the data on angiogenesis related to exosomes secreted by tumor cells in hematologic neoplasia and to elucidate the role of exosomes and exosomal miRNA in the bone marrow microenvironment, especially under hypoxic conditions. RECENT FINDINGS: Cross-talk between bone marrow tumor cells and surrounding cells, including endothelial cells, is important for tumor growth in hematologic neoplasia. In addition to conventional signaling pathways, exosomes, which are small endosome-derived vesicles containing miRNAs, can help to modulate the microenvironment without directly contacting nontumorous cells. The human myeloid leukemia cell line K562 secretes exosomes containing a large amount of miR-92a that enhances angiogenesis under normoxic and hypoxic conditions. With chronic hypoxia, exosomes secreted by multiple myeloma cells also enhance angiogenesis by targeting factor-inhibiting hypoxia-inducible factor-1 via miR-135b. SUMMARY: Intercellular communication between tumor cells and a heterogeneous population of bone marrow stromal cells is mediated by exosomes containing various functional proteins, mRNA, and miRNA. Hypoxia is a major regulator of exosomal content and affects angiogenesis in various types of hematologic neoplasia. Functional analysis of exosomes and exosome-mediated cell-cell interactions not only clarifies molecular pathogenesis but also suggests new treatment strategies for hematologic neoplasia through targeting exosomes.

Exosomal miR-135b shed from hypoxic multiple myeloma cells enhances angiogenesis by targeting factor-inhibiting HIF-1.

Exosomes are small endosome-derived vesicles containing a wide range of functional proteins, mRNA, and miRNA. Exosomal miRNA from cancer cells helps modulate the microenvironment. In multiple myeloma (MM), the massive proliferation of malignant plasma cells causes hypoxia. To date, the majority of in vitro hypoxia studies of cancer cells have used acute hypoxic exposure (3-24 hours). Thus, we attempted to clarify the role of MM-derived exosomes in hypoxic bone marrow by using MM cells grown continuously in vitro under chronic hypoxia (hypoxia-resistant MM [HR-MM] cells). The HR-MM cells produced more exosomes than the parental cells under normoxia or acute hypoxia conditions, and miR-135b was significantly upregulated in exosomes from HR-MM cells. Exosomal miR-135b directly suppressed its target factor-inhibiting hypoxia-inducible factor 1 (FIH-1) in endothelial cells. Finally, exosomal miR-135b from HR-MM cells enhanced endothelial tube formation under hypoxia via the HIF-FIH signaling pathway. This in vitro HR myeloma cell model will be useful for investigating MM cell-endothelial cell interactions under hypoxic conditions, which may mimic the in vivo bone marrow microenvironment. Although tumor angiogenesis is regulated by various factors, exosomal miR-135b may be a target for controlling MM angiogenesis.

Downregulation of Plasma miR-215 in Chronic Myeloid Leukemia Patients with Successful Discontinuation of Imatinib.

Approximately 40% of chronic myeloid leukemia (CML) patients who discontinue imatinib (IM) therapy maintain undetectable minimal residual disease (UMRD) for more than one year (stopping IM (STOP-IM)). To determine a possible biomarker for STOP-IM CML, we examined plasma miRNA expression in CML patients who were able to discontinue IM. We first screened candidate miRNAs in unselected STOP-IM patients, who had sustained UMRD after discontinuing IM for more than six months, in comparison with healthy volunteers, by using a TaqMan low-density array for plasma or exosomes. Exosomal miR-215 and plasma miR-215 were downregulated in the STOP-IM group compared to the control, indicating that the biological relevance of the plasma miR-215 level is equivalent to that of the exosomal level. Next, we performed real-time quantitative RT-PCR in 20 STOP-IM patients, 32 patients with UMRD on continued IM therapy (IM group) and 28 healthy volunteers. The plasma miRNA-215 level was significantly downregulated in the STOP-IM group (p < 0.0001); we determined the cut-off level and divided the IM group patients into two groups according to whether the plasma miR-215 was downregulated or not. The IM group patients with a low plasma miR-215 level had a significantly higher total IM intake, compared to the patients with elevated miR-215 levels (p = 0.0229). Functional annotation of miR-215 target genes estimated by the Database for Annotation, Visualization and Integrated Discovery (DAVID) bioinformatic tools involved cell cycle, mitosis, DNA repair and cell cycle checkpoint. Our study suggests a possible role of miR-215 in successful IM discontinuation.

Frequency of del(12p) is commonly underestimated in myelodysplastic syndromes: Results from a German diagnostic study in comparison with an international control group.

In myelodysplastic syndromes (MDS), deletion of the short arm of chromosome 12 (del(12p)) is usually a small abnormality, rarely detected as a single aberration by chromosome banding analysis (CBA) of bone marrow metaphases. Del(12p) has been described in 0.6 to 5% of MDS patients at initial diagnosis and is associated with a good to intermediate prognosis as a sole anomaly according to current scoring systems. Here, we present the results of a systematic del(12p) testing in a German prospective diagnostic study (clinicaltrials.gov: NCT01355913) on 367 MDS patients in whom CD34+ peripheral blood cells were analysed for the presence of del(12p) by sequential fluorescence in situ hybridization (FISH) analyses. A cohort of 2,902 previously published MDS patients diagnosed by CBA served as control. We demonstrate that, using a sensitive FISH technique, 12p deletion occurs significantly more frequently in MDS than previously described (7.6% by CD34+ PB-FISH vs. 1.6% by CBA, P < 0.001) and is often associated with other aberrations (93% by CD34+ PB-FISH vs. 60% by CBA). Additionally, the detection rate can be increased by repeated analyses in a patient over time which is important for the patient´s prognosis to distinguish a sole anomaly from double or complex aberrations. To our knowledge, this is the first study to screen for 12p deletions with a suitable probe for ETV6/TEL in 12p13. Our data suggest that the supplement of a probe for the detection of a 12p deletion to common FISH probe panels helps to avoid missing a del(12p), especially as part of more complex aberrations.

Musculoskeletal pain after stopping tyrosine kinase inhibitor in patients with chronic myeloid leukemia: a questionnaire survey.

We conducted a questionnaire survey to assess the state of patients with CML after discontinuation of TKI therapy. Nine of 27 patients developed musculoskeletal pain after TKI discontinuation. One had discontinued nilotinib and eight had discontinued imatinib therapy. Median time to symptom development after discontinuation was 2 weeks. Four experienced grade 3 symptoms as per the CTCAE ver. 4.0. One had pain persisting over a period of 21 months. There was a significant difference between patients with and without symptoms as regards female gender and the probability of persistent MMR. Awareness of this withdrawal syndrome after TKI discontinuation is imperative.

Validation of cytogenetic risk groups according to International Prognostic Scoring Systems by peripheral blood CD34+FISH: results from a German diagnostic study in comparison with an international control group.

International Prognostic Scoring Systems are used to determine the individual risk profile of myelodysplastic syndrome patients. For the assessment of International Prognostic Scoring Systems, an adequate chromosome banding analysis of the bone marrow is essential. Cytogenetic information is not available for a substantial number of patients (5%-20%) with dry marrow or an insufficient number of metaphase cells. For these patients, a valid risk classification is impossible. In the study presented here, the International Prognostic Scoring Systems were validated based on fluorescence in situ hybridization analyses using extended probe panels applied to cluster of differentiation 34 positive (CD34(+)) peripheral blood cells of 328 MDS patients of our prospective multicenter German diagnostic study and compared to chromosome banding results of 2902 previously published patients with myelodysplastic syndromes. For cytogenetic risk classification by fluorescence in situ hybridization analyses of CD34(+) peripheral blood cells, the groups differed significantly for overall and leukemia-free survival by uni- and multivariate analyses without discrepancies between treated and untreated patients. Including cytogenetic data of fluorescence in situ hybridization analyses of peripheral CD34(+) blood cells (instead of bone marrow banding analysis) into the complete International Prognostic Scoring System assessment, the prognostic risk groups separated significantly for overall and leukemia-free survival. Our data show that a reliable stratification to the risk groups of the International Prognostic Scoring Systems is possible from peripheral blood in patients with missing chromosome banding analysis by using a comprehensive probe panel (clinicaltrials.gov identifier:01355913).

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).

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.