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Recent advances in acute myeloid leukemia (AML) biology and its genetic landscape should ultimately lead to more subsetspecific AML therapies, ideally tailored to each patient's disease. Although a growing number of distinct AML subsets have been increasingly characterized, patient management has remained disappointingly uniform. If one excludes acute promyelocytic leukemia, current AML management still relies largely on intensive chemotherapy and allogeneic hematopoietic stem cell transplantation (HSCT), at least in younger patients who can tolerate such intensive treatments. Nevertheless, progress has been made, notably in terms of standard drug dose intensification and safer allogeneic HSCT procedures, allowing a larger proportion of patients to achieve durable remission. In addition, improved identification of patients at relatively low risk of relapse should limit their undue exposure to the risks ofHSCTin first remission. The role of new effective agents, such as purine analogs or gemtuzumab ozogamicin, is still under investigation, whereas promising new targeted agents are under clinical development. In contrast, minimal advances have been made for patients unable to tolerate intensive treatment, mostly representing older patients. The availability of hypomethylating agents likely represents an encouraging first step for this latter population, and it is hoped will allow for more efficient combinations with novel agents. [ABSTRACT FROM AUTHOR]

From 1968 to 1993, 179 newly diagnosed patients with polycythemia vera (PV) were enrolled in a prospective study using pipobroman as first chemotherapy. Among them, 140 fulfilled the Polycythemia Vera Study Group criteria for PV, and 39 patients (22%) can be considered as idiopathic erythrocytosis (IE). Vascular events occurred in 10% of IE and 20% of PV patients and solid tumors in 7.7% of IE and 12.8% of PV patients. There were no differences between PV and IE patients with regard to progression to myelofibrosis (MF), leukemic events and overall survival. Overall, 98.3% of patients initially responded to pipobroman, with very mild toxicity. A total of 164 PV patients who received more than 1 year of pipobroman were analyzed for long-term evolution. The actuarial risk of thrombosis was 15.6 and 23.8% at 10 and 18 years, respectively. In all, 21 patients developed a solid tumor during follow-up, added and/or switched drugs being a risk factor. Actuarial risk of MF was as low as 4.9 and 9.4% at 10 and 15 years, respectively. Actuarial risk of leukemia was 14.4 and 18.7% at 10 and 15 years, respectively. Hyperleukocytosis at diagnosis was the only variable significantly associated with higher risk of leukemia. The median survival was 15.5 years, with two initial adverse prognostic factors: age above 60 years and hyperleukocytosis. Despite an increasing risk of leukemia with time, survival was not lower when compared to the French matched population. Only age and hyperleukocytosis at diagnosis were found to have a prognostic value in PV. [ABSTRACT FROM AUTHOR]

The article highlights the long-term results of two large, randomized trials on managing acute myeloid leukemia (AML) conducted by investigators from the Eastern Cooperative Oncology Group (ECOG) in the U.S. and a collaborative group of European investigators from the Netherlands, Belgium, Germany and Switzerland. Among the factors that negatively influence the outcome of patients with AML are older age, poor performance status and high white-cell count. Both studies have concluded that the 90-milligram (mg) dose of daunorubicin, as compared with the standard 45-mg dose, appear to be similar. According to the authors, high-dose daunorubicin does not benefit the majority of older patients with AML.

Ph+ (BCR::ABL+) B-ALL was considered to be high risk, but recent advances in BCR::ABL-targeting TKIs has shown improved outcomes in combination with backbone chemotherapy. Nevertheless, new treatment strategies are needed, including approaches without chemotherapy for elderly patients. LIMK1/2 acts downstream from various signaling pathways, which modifies cytoskeleton dynamics via phosphorylation of cofilin. Upstream of LIMK1/2, ROCK is constitutively activated by BCR::ABL, and upon activation, ROCK leads to the phosphorylation of LIMK1/2, resulting in the inactivation of cofilin by its phosphorylation and subsequently abrogating its apoptosis-promoting activity. Here, we demonstrate the anti-leukemic effects of a novel LIMK1/2 inhibitor (LIMKi) CEL_Amide in vitro and in vivo for BCR::ABL-driven B-ALL. The IC50 value of CEL_Amide was ≤1000 nM in BCR::ABL+ TOM-1 and BV-173 cells and induced dose-dependent apoptosis and cell cycle arrest in these cell lines. LIMK1/2 were expressed in BCR::ABL+ cell lines and patient cells and LIMKi treatment decreased LIMK1 protein expression, whereas LIMK2 expression was unaffected. As expected, CEL_Amide exposure caused specific activating downstream dephosphorylation of cofilin in cell lines and primary cells. Combination experiments with CEL_Amide and BCR::ABL TKIs imatinib, dasatinib, nilotinib, and ponatinib were synergistic for the treatment of both TOM-1 and BV-173 cells. CDKN2Ako/BCR::ABL1+ B-ALL cells were transplanted in mice, which were treated with combinations of CEL_Amide and nilotinib or ponatinib, which significantly prolonged their survival. Altogether, the LIMKi CEL_Amide yields activity in Ph+ ALL models when combined with BCR::ABL-targeting TKIs, showing promising synergy that warrants further investigation. [ABSTRACT FROM AUTHOR]

The bromodomain and extra-C-terminal domain (BET) protein family is a class of epigenetic readers that recognize acetyl-lysine residues of histones, and their targeting with small molecules is a novel therapeutic approach [[1]]. Cell cycle and apoptosis induction were evaluated in a subset of cell lines, including two resistant models (NALM1, K562) after 48-h treatments with 500 nM OTX015 (Figure 1(A)). Similarly, OTX015 significantly down-regulated I MTHFD1L i and I BCL2 i in all leukemic cell lines after 4 or 24 h of treatment, in a similar manner as I MYC i , although the effect on I BCL2 i appeared reversible in three nonresistant cell lines (Figure S2). We then evaluated the downstream effects of OTX015 (500 nM) combined with azacitidine (3 µM) or panobinostat (20 nM) in sensitive and resistant OTX015 cell lines. [Extracted from the article]

Azacitidine (AZA) prolonged overall survival (OS) in the AZA-AML-001 trial. However, few subjects were randomized to AZA or intensive chemotherapy (IC). The Medical Research Council (MRC) and the Leukemia Research Foundation (LRF) developed a score for older AML patients receiving IC or non-intensive regimens, whereas the E-ALMA study validated a score for survival and response in elderly patients receiving AZA in daily practice. Both identified three groups with different risk estimates. This analysis evaluates the efficacy of frontline AZA in older AML patients (N = 710) unfit for IC from different national registries (E-ALMA + series) stratified by the MRC/LRF risk score. Median OS of patients categorized as good, standard and poor-risk groups by the MRC/LRF score was 13.4 (95% CI, 10.8-16), 12.4 (95% CI, 9.9-14.8), and 8.1 months (95% CI, 7-9.1), respectively (p = .0001). In conclusion, this is the largest retrospective cohort of older AML patients treated with AZA. [ABSTRACT FROM AUTHOR]

We wanted to describe the characteristics, treatment and outcome of autoimmune and inflammatory diseases (SAIDs) associated with chronic myelomonocytic leukemia (CMML), and conducted a French multicenter retrospective study and a literature review. We included 26 cases of CMML (median age 75 years, 54% female), 80% with CMML-1. CPSS score was low (0 or 1) in 75% of cases. SAIDS was systemic vasculitis in 54%. Diagnosis of the 2 diseases was concomitant in 31% cases, and CMML was diagnosed before SAIDs in 12 cases (46%). First line treatment for SAIDs consisted mostly of steroid, with 85% of response. Second-line treatment was needed in 40% cases. Six patients received hypomethylating agents, with 66% response on SAIDs. A literature review found 49 cases of CMML-associated SAIDs, in whom SAIDs was systemic vasculitis in 29% cases. Hence, vasculitis is the most frequent SAIDs associated with CMML. After initial response to steroids, recurrence and steroid-dependence were frequent. Hypomethylating agents may be interesting in this context. [ABSTRACT FROM AUTHOR]

This retrospective study describes efficacy of Azacitidine on autoimmune disorders (AID) associated with MDS/CMML in 22 patients. Response of AID to Azacitidine was observed in 19 patients (86%). Reduction or discontinuation of steroids and/or immunosuppressive therapy (IST) was possible in 16 cases (73%). Hematologic response was seen in 55% of the patients. MDS/CMML and AID evolution was concordant in 13 cases (59%): both favorable (n = 11), both unfavorable (n = 2), but AID improved while MDS/CMML worsened (n = 8) and vice versa (n = 1). Azacitidine frequently seems effective in controlling steroid-dependent AID associated with MDS/CMML, but prospective studies are necessary to confirm those findings. [ABSTRACT FROM AUTHOR]

Outcome of patients with high risk MDS and CMML who failed treatment with azacitidine remains poor with a median survival of 6 months, without established therapy available except allogeneic hematopoietic stem cell transplantation. The objective of our study was to evaluate efficacy of decitabine after azacitidine failure in a relatively large patient cohort based on conflicting results with 0–28% response rates (RR) in this setting in small patient series. Thirty-six consecutive high risk MDS and CMML patients who received decitabine after azacitidine failure were retrospectively reviewed. Response was based on IWG 2006 criteria for MDS and CMML with WBC <13 G/l and also included for proliferative CMML the evolution of WBC, splenomegaly (SMG) and extramedullary disease (EMD). Patients received a median number of 3 (range 1–27) cycles of decitabine and 12 patients received at least 6 cycles. Seven (19.4%) patients were responders including 3 marrow CR (mCR), 2 stable disease (SD) with HI-E, 1 SD with HI-N and HI-P and 1 SD with HI-N. In a CMML patient with SD, specific skin lesions resolved with decitabine. Responses were generally short lived (2–5 months) except 1 responder currently ongoing with +11 months follow up. Two non-responders had prolonged SD (without HI) of 21 and 27 months duration respectively. Median OS from onset of decitabine was 7.3 months, without significant difference between responders and non-responders. Treatment with decitabine after azacitidine failure yielded modest ORR (19.4%) with short response duration and poor OS. Thus, use of decitabine in such patients who failed or progressed after azacitidine cannot be recommended, underscoring the need for novel strategies in this setting. [ABSTRACT FROM AUTHOR]

Abstract: Forty-seven percent of adults with acute myeloid leukemia (AML) who entered the ALFA-9802 trial and achieved a first complete remission (CR) experienced a first relapse. We examined the outcome of these 190 adult patients. Eighty-four patients (44%) achieved a second CR. The median overall survival (OS) after relapse was 8.9months with a 2-year OS at 25%. Factors predicting a better outcome after relapse were stem cell transplant (SCT) performed in second CR and a first CR duration >1year. Risk groups defined at the time of diagnosis and treatment received in first CR also influenced the outcome after relapse. The best results were obtained in patients with core binding factor (CBF)-AML, while patients initially defined as favorable intermediate risk showed a similar outcome after relapse than those initially entering the poor risk group. We conclude that most adult patients with recurring AML could not be rescued using current available therapies, although allogeneic SCT remains the best therapeutic option at this stage of the disease. [Copyright &y& Elsevier]

Infections are a major complication in patients with acute myeloid leukemia undergoing intensive chemotherapy. They remain a major cause of therapy-associated morbidity and mortality, and represent a frequent cause of treatment withdrawal. An analysis of the medical charts of 459 younger adults included in the multicenter Acute Leukemia French Association (ALFA)-9802 trial showed that 1369 febrile episodes occurred among the 459 registered patients, including fever without identifiable source (23%) and clinically or microbiologically documented infections (77%). Bloodstream infections occurred in 314 episodes, including 129 documented episodes with Gram-positive and 96 with Gram-negative pathogens. Pulmonary infection was diagnosed in 144/1054 documented infectious episodes (14%). Invasive fungal infection was probable or proven in 116 patients. In all, 15 patients died of infection-associated complications, of whom seven died during early induction therapy, one during salvage therapy and seven during consolidation therapy. Better supportive care strategies may improve overall survival in patients undergoing chemotherapy for acute myeloid leukemia. [ABSTRACT FROM AUTHOR]

Abstract: FLT3 internal tandem duplication (FLT3-ITD) is usually considered as a bad marker for minimal residual disease (MRD) follow-up in acute myeloid leukemia (AML). Our objective was to evaluate the suitability of FLT3-ITD as a target for MRD detection by real-time quantitative PCR, in comparison with two other molecular MRD markers, NPM1 mutation and WT1 overexpression, in 20 adult AML patients treated in Acute Leukemia French Association (ALFA) trials. Overall, these 3 MRD markers showed comparable kinetics in 17/20 (85%) cases. Furthermore, we found that FLT3-ITD MRD levels after induction chemotherapy are predictive of complete remission duration. [Copyright &y& Elsevier]

Abstract: Initially, tyrosine kinase inhibitors (TKIs) were developed as targeted therapies that would solely interfere with aberrant tyrosine kinase activation in malignant cells. Nevertheless, preclinical and clinical studies demonstrated that TKI also exhibit “off-target” effects, that is effects not mediated by the assumed mechanisms of action. We and others showed that the epidermal growth factor receptor (EGFR) inhibitors erlotinib and gefitinib exert potent antineoplastic effects on EGFR-negative myeloblasts from patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Here, we undertook a side-by-side comparison of the anti-leukemic efficacy of four different TKI in MDS and AML. Besides the EGFR inhibitor erlotinib, which served as a point of reference, we employed the dual EGFR/HER2 TKI lapatinib, as well as the multikinase inhibitors dasatinib and sorafenib. All four drugs had anti-leukemic effects on cell line models of MDS/AML in vitro as well as on malignant blasts from MDS/AML patients ex vivo. We explored the biological phenomena underlying this anti-leukemic efficacy. Since it is established that a therapeutic benefit in MDS/AML can be conveyed by induction of cell cycle arrest, apoptosis and/or differentiation, we deciphered the individual contribution of these three phenomena to the anti-leukemic action of each of the four TKI. The concomitant assessment of the panel of TKI enables us thus to define (and quantify) their differential capacity to impact on the three biological phenomena, and provide further evidence that these mechanisms are not solely explained by on-target effects. [Copyright &y& Elsevier]

Hydroxyurea is the standard therapy of chronic myelomonocytic leukemia (CMML) presenting with advanced myeloproliferative and/or myelodysplastic features. Response to hypomethylating agents has been reported in heterogeneous series of CMML. We conducted a phase 2 trial of decitabine (DAC) in 39 patients with advanced CMML defined according to a previous trial. Median number of DAC cycles was 10 (range, 1-24). Overall response rate was 38% with 4 complete responses (10%), 8 marrow responses (21%), and 3 stable diseases with hematologic improvement (8%). Eighteen patients (46%) demonstrated stable disease without hematologic improvement, and 6 (15%) progressed to acute leukemia. With a median follow-up of 23 months, overall survival was 48% at 2 years. Mutations in ASXL1, TET2, AML1, NRAS, KRAS, CBL, FLT3, and janus kinase 2 (JAK2) genes, and hypermethylation of the promoter of the tumor suppressor gene TIF1γ, did not predict response or survival on DAC therapy. Lower CJUN and CMYB gene expression levels independently predicted improved overall survival. This trial confirmed DAC efficacy in approximately 40% of CMML patients with advanced myeloproliferative or myelodysplastic features and suggested that CJUN and CMYB expression could be potential biomarkers in this setting. [ABSTRACT FROM AUTHOR]

To assess the value of administering timed-sequential chemotherapy (TSC; 2 therapeutic sequences separated by a 4-day interval-free chemotherapy) or high-dose cytarabine (HDAraC) cycles in consolidation therapy for acute myeloid leukemia (AML), 459 patients 15 to 50 years of age were enrolled in the prospective randomized Acute Leukemia French Association-9802 trial. Complete remission was achieved in 89%. A total of 237 patients were then randomized to either TSC consolidation (120 patients) or HDAraC consolidation cycles (117 patients). Overall, there was no significant difference between the 2 consolidation arms (5-year event-free survival [EFS]: 41% for HDAraC vs 35% for TSC), or cumulative incidence of relapse, or treatment-related mortality. Cytogenetically normal AML NPM1+ or CEBPA+ and FLT3-ITD- had the same outcome as those with favorable cytogenetics. When considering favorable and unfavorable risk groups, the trend was in favor of HDAraC. However, the difference became significant when considering intermediate cytogenetics (5-year EFS: 49% vs 29%; P = .02), especially cytogenetically normal AML (5-year EFS: 48% vs 31%; P = .04), which was related to lower relapse rate and less toxicity. This study demonstrates that TSC did not produce any benefit when used as consolidation therapy in younger adults compared with HDAraC. This trial was registered at www.clinicaltrials.gov as #NCT00880243. [ABSTRACT FROM AUTHOR]

The article presents a study on leukemic cell priming with granulocyte-macrophage colony-stimulating factor (GM-CSF) which may modulate cell cycle kinetics and susceptible to phase-specific chemotherapeutic agents. In this study, cytogenetics, mutation detection and statistical analysis were used to 259 patients with acute myeloid leukemia (AML). The results show that priming of leukemia cells with GM-CSF may enhance complete remission (CR) rate and event-free survival (EFS).

Abstract: Erlotinib and gefitinib, two inhibitors of the epidermal growth factor receptor (EGFR), can stimulate apoptosis and differentiation of myeloid cell lines that lack EGFR, unveiling a novel, therapeutically exploitable off-target effect of tyrosine kinase inhibitors. Here, we performed a side-by-side comparison of erlotinib and gefitinib effects on a broad spectrum of malignant myeloid cell lines, as well as on primary myeloblasts freshly purified from the bone marrow of patients with myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Both erlotinib and gefitinib induce apoptosis of a cell line (KG-1) that represents AML, and differentiation in another cell line (P39) derived from a patient with high-risk MDS. In this setting, erlotinib was more efficient than gefitinib. Erlotinib and gefitinib were equipotent in inducing apoptosis of primary CD34+ myeloblasts from MDS and AML patients, yet had no toxic effect on CD34+ progenitor cells from healthy donors. Although the response of individual MDS and AML patients in vitro was highly heterogeneous, the pro-apoptotic effects of erlotinib and gefitinib correlated significantly. These results suggest that erlotinib and gefitinib share a mechanistically related off-target effect that may be taken advantage of for the therapy of MDS and AML. [Copyright &y& Elsevier]

Several reports of successful empirical treatment of idiopathic hypereosinophilic syndrome with imatinib led to the recent identification of the FIP1L1–PDGFRA fusion gene rearrangement, which characterizes a distinctive group of chronic eosinophilic leukemias. This fusion gene can be detected in eosinophils, neutrophils, mast cells, T cells, B cells and monocytes in FIP1L1–PDGFRA-positive hypereosinophilic patients suggesting a multilineage involvement. Furthermore, the same FIP1L1–PDGFRA rearrangement was identified in patients with hypereosinophilia and atypical mast cell proliferations, raising the question of a disease with two concomitant lines of differentiation. In addition, a recent report noted two cases with the association of FIP1L1–PDGFRA-positive chronic eosinophilic leukemia and T-cell lymphoblastic lymphoma (T-LBL). We report here the only third case of synchronous chronic eosinophilic leukemia and T-LBL, both associated with a FIP1L1–PDGFRA fusion transcript, confirming the occurrence of such disease and suggesting a clonal proliferation with two lines of differentiation probably arising from a primitive multipotent medullary stem cell. [ABSTRACT FROM AUTHOR]

In all, 236 adults with newly diagnosed acute lymphoblastic leukemia (ALL) were randomly assigned to receive either granulocyte colony-stimulating factor (G-CSF), or granulocyte- macrophage CSF (GM-CSF), or no CSF during a 4-week 4-drugs induction chemotherapy. Two successive trials were performed. CSFs were given from the last infusion of anthracycline in Trial 1 or from day 4 of induction therapy in Trial 2 until neutrophil recovery. A total of 95 patients were included in the G-CSF group, 67 in the GM-CSF group, and 74 in the control group. Overall, CSFs showed a trend for a reduced incidence of severe infections and of days with antibiotics. Median time for neutrophil recovery was 17 days with G-CSF, 18 days with GM-CSF, and 21 days without CSF. In Trial 2, duration of hospitalization was significantly lower in the G-CSF group than in the other groups (P<0.05). Time to neutrophil recovery was also significantly shorter (P<0.05) and severe infections were lower in the G-CSF group (P= 0.01). CR rate was higher in the GM-CSF group as compared to the control group. This tended to be confirmed for the most aggressive ALL and was statistically significant for Philadelphia-positive ALL after salvage therapy (P = 0.04). There were no significant differences between the three groups in terms of disease-free survival. [ABSTRACT FROM AUTHOR]

In all, 625 patients with acute lymphoblastic leukemia (ALL) entered the Leucémie Aiguë Lymphoblastique de l'Adulte-94 trial from June 1994 to June 1999, and received a 4-week induction therapy followed either by chemotherapy alone or stem cell transplantation (SCT). In a clinical phase II study, 40 patients with standard- or high-risk ALL - except Philadelphia chromosome-positive ALL -, relapsing at least 3 months after the beginning of therapy and who did not receive any SCT, received a rescue protocol combining amsacrine 120?mg/m2/day, days 1-3, cytarabine 1?g/m2/12?h, days 1-5, and etoposide 100?mg/m2/day, days 1-5. All relapses occurred ‘on therapy’. In all, 16 patients (40%) achieved a second complete remission. The median time to neutrophil recovery >0.5 × 109/l was 27 days. The median time to platelet recovery >50 × 109/l was 28 days. Extra-hematologic toxicity was mild (only one toxic death from severe infection). The median overall survival was 5.4 months. The median disease-free survival (DFS) was 3.2 months with a 3-year DFS of 12%. Unfavorable prognostic factors for complete remission achievement were: high-risk ALL at diagnosis (P=0.03), and white blood cell count at relapse =30 × 109/l (P=0.02). No relationship was found between survival and any characteristics of the disease. Four patients underwent allogeneic SCT (two phenoidentical and two genoidentical) and three patients received autologous SCT. This treatment combining amsacrine, cytarabine, and etoposide was therefore effective and well tolerated in ‘on-therapy’-relapsed ALL. However, the median DFS was short requiring the rapid completion of effective intensive postremission therapy.The Hematology Journal (2004) 5, 123-129. doi:10.1038/sj.thj.6200353 [ABSTRACT FROM AUTHOR]

In spite of the recent improvement in the outcome of acute promyelocytic leukaemia (APL) with treatment combining all trans retinoic acid (ATRA) and chemotherapy (CT), some patients with this disease still have a poor outcome. The prognostic significance of chromosomal abnormalities in addition to t(15;17) in APL is uncertain. We examined the prognostic significance of secondary chromosomal changes in 292 patients included in a European trial who were treated with ATRA and CT. The incidence of chromosomal abnormalities in addition to t(15;17) was 26% and trisomy 8 was the most frequent secondary change (46% of the cases with secondary changes). No significant differences were seen with regard to age, sex, initial white blood cell count, % of circulating blasts, platelet count, fibrinogen level and incidence of microgranular variants between patients with or without additional rearrangements. Outcome was also similar between patients with t(15;17) alone and patients with t(15;17) and other clonal abnormalities for complete remission (92% vs. 93% respectively), event-free survival at 2 years (76·1% vs. 78·1% respectively), relapse at 2 years (16·7% vs. 11·6% respectively) and overall survival at 2 years (79·9% vs. 79·5% respectively). Analysis according to the type of induction treatment (ATRA followed by CT or ATRA plus CT) or the type of maintenance treatment (with ATRA, low-dose CT or both) also failed to show any difference between the two groups. Thus, in a large cohort of APL patients treated with ATRA and CT, additional chromosomal abnormalities had no impact on prognosis. [ABSTRACT FROM AUTHOR]

• LIM kinase 1 and 2 are expressed in FLT3-ITD mutated AML cell lines. • The LIMK1/2 inhibitor CEL_Amide has antiproliferative effects in those cells. • CEL_Amide synergizes with FLT3-ITD inhibitors in vitro and in vivo. • Dephosphorylation of cofilin constitutes a potential biomarker for LIMK1/2 action. Patients with FLT3-ITD mutated (FLT3-ITD+) Acute Myeloid Leukemia (AML), have frequently relapsed or refractory disease and FLT3-ITD+ inhibitors have limited efficacy. Rho kinases (ROCK) are constitutively activated by FLT3-ITD+ in AML via PI3 kinase and Rho GTPase. Upon activation by ROCK, LIM kinases (LIMK) inactivate cofilin by phosphorylation which affects cytoskeleton dynamics, cell growth and apoptosis. LIMK inhibition leads to cofilin activation via dephosphorylation and activated cofilin localizes to mitochondria inducing apoptosis. Thus, we investigated the therapeutic potential of the LIMK1/2 inhibitor CEL_Amide (LIMKi) in FLT3-ITD+ AML. Expression of LIMK1/2 in FLT3-ITD+ cell lines MOLM-13 and MV-4-11 cells could be detected by RT-qPCR and at the protein level. IC50 after LIMKi monotherapy was 440 nM in MOLM-13 cells and 420 nM in MV4-11 cells. Treatment with LIMKi decreased LIMK1 protein levels and repression of inactivating phosphorylation of cofilin in FLT3-ITD+ cells. Combination experiments with LIMKi and FLT3 inhibitors including midostaurin, crenolanib and gilteritinib were synergistic for treatment of MOLM-13 cells while combinations with quizartinib were additive. Combinations of LIMKi and the hypomethylating agent azacitidine or the ROCK inhibitor fasudil were additive. In NOD-SCID mice engrafted with MOLM13-LUC cells, the FLT3 inhibitor midostaurin and LIMKi delayed MOLM13-LUC engraftment as detected by in vivo bioluminescence imaging and the LIMKi and midostaurin combination prolonged significantly survival of leukemic mice. LIMK1/2 inhibition by the small molecule CEL_Amide seems to have promising activity in combination with FLT3 inhibitors in vitro as well as in vivo and may constitute a novel treatment strategy for FLT3-ITD+ AML. [ABSTRACT FROM AUTHOR]

The article presents information on a study which showed that the outcome of high risk myelodysplastic syndrome (MDS) after azacitidine (AZA) failure. The study the outcome of 74 patients with secondary acute myeloid leukaemia (AML) after AZA treatment failure, collected from two Johns Hopkins University trials and the French AZA compassionate programme.

Bromodomain and Extra-Terminal inhibitors (BETi) such as OTX015 are active in Acute Myeloid Leukaemias (AML). Their activity on Leukemic Stem Cells (LSCs) is less documented. We interrogated the anti-LSC activity of OTX015 in a niche-like long-term culture in 26 primary AML samples and validated our findings in vivo. OTX015 impaired LSCs in AMLs harbouring Core Binding Factor or KMT2A gene fusions, NPM1 or chromatin/spliceosome genes mutations, but not in those with aneuploidy/TP53 mutations. In four patients, we dissected the transcriptomic footprint of Bet inhibition on LSCs versus blasts. Our results can instruct future clinical trials of BETi in AML. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented which talks about the risks associated with azacitidine treatment of myelodysplastic syndromes (MDS) patients is presented.

The article reports that activating somatic mutations in Tyrosine Kinase (TK) genes are frequent events in haematological malignancies. The structural and functional consequences of these mutations were variable in molecular modelling. Group for Research on Adult Acute Lymphoblastic Leukaemia (GRAAL) study included assesment of JAK1, a Janus Kinase (JAK) family member.