How I treat chronic myelomonocytic leukemia. Blood. 2017;130:126-136. [PMID: 28572287 DOI: 10.1182/blood-2017-04-736421]

Venetoclax is effective for chronic myelomonocytic leukemia blastic transformation with RUNX1 mutation

Background: Chronic myelomonocytic leukemia is a clonal hematological disorder with an inherent risk of transformation to acute myeloid leukemia. Recently, there has been exponential discovery of molecular abnormalities in patients with chronic myelomonocytic leukemia. Some of these mutations independently contribute to a higher risk of transformation and result in inferior overall survival. Treatment strategies for patients undergoing blastic transformation in chronic myelomonocytic leukemia, especially after progressing on hypomethylating agents, are currently limited.Case presentation: We present a case of a 70-year-old male patient with chronic myelomonocytic leukemia blastic transformation with RUNX1 mutation following azacitidine monotherapy. Notably, he achieved hematological complete remission after the first course of venetoclax plus azacitidine, leading to the disappearance of RUNX1 mutation. We performed serial assessments of molecular analysis by next generation sequencing throughout his clinical course.Conclusion: The presence of RUNX1 mutation is associated with higher response rates to venetoclax-based combination therapies in chronic myelomonocytic leukemia with blastic transformation. Our findings suggest that even after azacitidine monotherapy, venetoclax plus azacitidine is effective in targeting leukemic clones harboring RUNX1 mutations. Furthermore, we emphasize the significance of molecular analysis, including next-generation sequencing, in providing insights into the detailed dynamics of clonal evolution and guiding treatment decisions.

CBL mutations in chronic myelomonocytic leukemia often occur in the RING domain with multiple subclones per patient: Implications for targeting

Chronic myelomonocytic leukemia (CMML) is a rare blood cancer of older adults (3 in every 1,000,000 persons) characterized by poor survival and lacking effective mutation-specific therapy. Mutations in the ubiquitin ligase Cbl occur frequently in CMML and share biological and molecular features with a clonal disease occurring in children, juvenile myelomonocytic leukemia (JMML). Here we analyzed the clinical presentations, molecular features and immunophenotype of CMML patients with CBL mutations enrolled in a prospective Phase II clinical trial stratified according to molecular markers. Clinically, CBL mutations were associated with increased bone marrow blasts at diagnosis, leukocytosis and splenomegaly, similar to patients harboring NRAS or KRAS mutations. Interestingly, 64% of patients presented with more than one CBL variant implying a complex subclonal architecture, often with co-occurrence of TET2 mutations. We found CBL mutations in CMML frequently clustered in the RING domain in contrast to JMML, where mutations frequently involve the linker helix region (P<0.0001). According to our comparative alignment of available X-ray structures, mutations in the linker helix region such as Y371E give rise to conformational differences that could be exploited by targeted therapy approaches. Furthermore, we noted an increased percentage of CMML CD34+ stem and progenitor cells expressing CD116 and CD131 in all CBL mutant cases and increased CD116 receptor density compared to healthy controls, similar to CMML overall. In summary, our data demonstrate that CBL mutations are associated with distinct molecular and clinical features in CMML and are potentially targetable with CD116-directed immunotherapy.

Temporal trend in survival for chronic myelomonocytic leukemia in the US: a population-based study

Outcomes for chronic myelomonocytic leukemia (CMML) are insufficiently characterized at the population level. We analyzed epidemiological trends for patients between 2001 and 2017, focusing on age, sex, race, and long-term survivors. Using the Surveillance, Epidemiology, and End Results Program, we studied 3929 patients, in four time-period (tp) cohorts, based on year of diagnosis [2001-2004 (tp1); 2005-2009 (tp2); 2010-2013 (tp3); 2014-2017 (tp4)]. Stable incidence overall, male predominance, and higher incidence for White versus Black and 'Other' races were noted. Three-year relative survival (RS) increased from 27.9% to 36.9% between tp1 and tp4. The most pronounced increase occurred between tp1 and tp2. All subgroups generally experienced RS improvements over time, except notably Black patients. Improvements for patients aged 85+ (3-year RS 8.4-23.6% between tp1 and tp4) and increases in long-term survivors (5-year OS from 13.2-22.3%) were observed. Additional study is warranted to explore these associations, particularly for Black patients.

Impact of a novel prognostic model on allogeneic hematopoietic stem cell transplantation outcomes in patients with CMML

Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell malignancy, and allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curable treatment. The outcomes after transplant are influenced by both disease characteristics and patient comorbidities. To develop a novel prognostic model to predict the post-transplant survival of CMML patients, we identified risk factors by applying univariable and multivariable Cox proportional hazards regression to a derivation cohort. In multivariable analysis, advanced age (hazard ratio [HR] 3.583), leukocyte count (HR 3.499), anemia (HR 3.439), bone marrow blast cell count (HR 2.095), and no chronic graft versus host disease (cGVHD; HR 4.799) were independently associated with worse survival. A novel prognostic model termed ABLAG (Age, Blast, Leukocyte, Anemia, cGVHD) was developed and the points were assigned according to the regression equation. The patients were categorized into low risk (0-1), intermediate risk (2, 3), and high risk (4-6) three groups and the 3-year overall survival (OS) were 93.3% (95%CI, 61%-99%), 78.9% (95%CI, 60%-90%), and 51.6% (95%CI, 32%-68%; p < .001), respectively. In internal and external validation cohort, the area under the receiver operating characteristic (ROC) curves of the ABLAG model were 0.829 (95% CI, 0.776-0.902) and 0.749 (95% CI, 0.684-0.854). Compared with existing models designed for the nontransplant setting, calibration plots, and decision curve analysis showed that the ABLAG model revealed a high consistency between predicted and observed outcomes and patients could benefit from this model. In conclusion, combining disease and patient characteristic, the ABLAG model provides better survival stratification for CMML patients receiving allo-HSCT.

An unusual response to 5-azacitidine by a patient with chronic myelomonocytic leukemia

Key Clinical Message

Hypomethylating agents may be useful in some but not all cases of myelodysplastic syndromes. In some versions of these conditions, this treatment may yield deleterious results.

Abstract

Chronic myelomonocytic leukemia (CMML) is considered to be a heterogeneous group of hematopoietic neoplasms. Usually it shares the features of myeloproliferative neoplasms (MPN) and myelodysplastic syndromes (MDS) and is known as MDS/MPN. It occurs mostly in the elderly and has an inherent tendency to transform to acute myeloid leukemia. FDA has approved hypomethylating agents (HMAs) such as 5-azacitidine (AZA) and decitabine (DEC) for the treatment of this disorder. The extent of response rate to AZA varies considerably among patients. Our report describes a patient with CMML who not only did not respond to a conventional dose of intravenous (IV) therapy with AZA, but showed marked progression of the disease with the leucocyte count rising exponentially while undergoing the aforesaid treatment. We believe this is the first such case reported in the currently extant literature.

Coexistence of three hematological malignancies in association with a first time documented mutation: "One train can hide another"°, and even more!

Coexisting malignancies is not only an uncommon event but, it can also represent a medical challenge. Its complexity relies on the difficulty of management and the need for personalized and prioritized therapeutic approaches, on the one hand, and in the potential misdiagnosis of recurrence or even a de novo disease, on the other. Here, we present a case of a 69-year-old patient, who was initially diagnosed with a chronic myelomonocytic leukemia (CMML), followed by monoclonal gammopathy of uncertain significance (MGUS). Few years later, the patient developed Hodgkin's lymphoma (HL), and a new mutation, previously undocumented in the medical literature, was also detected. As a conclusion, we can say that the decision must be taken with caution and must be based on two major factors: 1- The rapid evolution of malignancies: give priority to treating the most rapid/life-threatening disease. 2- Prioritize the treatment of symptomatic disease and/or that which may most improve patients' quality of life.

Proposals for Clinical Trials in Chronic Myelomonocytic Leukemia

OPINION STATEMENT

Chronic myelomonocytic leukemia (CMML) is a clonal hematologic malignancy of mostly older individuals that exhibits both myelodysplastic and myeloproliferative features. CMML presentation and outcome are variable, reflecting genetic and clinical heterogeneity. Hypomethylating agents are the mainstay of therapy but induce complete remissions in less than 20% of patients and do not prolong survival compared to hydroxyurea. Allogeneic stem cell transplant (ASCT) is potentially curative, but few patients qualify due to advanced age and/or comorbidities. Work of the past several years has identified key molecular pathways that drive disease proliferation and transformation to acute leukemia, including JAK/STAT and MAPK signaling and epigenetic dysregulation. There is increasingly compelling evidence that inflammation is a major driver of CMML progression. Thus far however, this mechanistic knowledge has not yet been translated into improved outcomes, suggesting that fundamentally new approaches are required. In this review, we discuss the disease course, new classifications, and current treatment landscape of CMML. We review ongoing clinical studies and discuss options for rationally based future clinical trials.

The spectrum of GATA2 deficiency syndrome

Inherited or de novo germ line heterozygous mutations in the gene encoding the transcription factor GATA2 lead to its deficiency. This results in a constellation of clinical features including nontuberculous mycobacterial, bacterial, fungal, and human papillomavirus infections, lymphedema, pulmonary alveolar proteinosis, and myelodysplasia. The onset, or even the presence, of disease is highly variable, even in kindreds with the identical mutation in GATA2. The clinical manifestations result from the loss of a multilineage progenitor that gives rise to B lymphocytes, monocytes, natural killer cells, and dendritic cells, leading to cytopenias of these lineages and subsequent infections. The bone marrow failure is typically characterized by hypocellularity. Dysplasia may either be absent or subtle but typically evolves into multilineage dysplasia with prominent dysmegakaryopoiesis, followed in some instances by progression to myeloid malignancies, specifically myelodysplastic syndrome, acute myelogenous leukemia, and chronic myelomonocytic leukemia. The latter 3 malignancies often occur in the setting of monosomy 7, trisomy 8, and acquired mutations in ASXL1 or in STAG2. Importantly, myeloid malignancy may represent the primary presentation of disease without recognition of other syndromic features. Allogeneic hematopoietic stem cell transplantation (HSCT) results in reversal of the phenotype. There remain important unanswered questions in GATA2 deficiency, including the following: (1) Why do some family members remain asymptomatic despite harboring deleterious mutations in GATA2? (2) What are the genetic changes that lead to myeloid progression? (3) What causes the apparent genetic anticipation? (4) What is the role of preemptive HSCT?

A noncanonical response to replication stress protects genome stability through ROS production, in an adaptive manner

Cells are inevitably challenged by low-level/endogenous stresses that do not arrest DNA replication. Here, in human primary cells, we discovered and characterized a noncanonical cellular response that is specific to nonblocking replication stress. Although this response generates reactive oxygen species (ROS), it induces a program that prevents the accumulation of premutagenic 8-oxoguanine in an adaptive way. Indeed, replication stress-induced ROS (RIR) activate FOXO1-controlled detoxification genes such as SEPP1, catalase, GPX1, and SOD2. Primary cells tightly control the production of RIR: They are excluded from the nucleus and are produced by the cellular NADPH oxidases DUOX1/DUOX2, whose expression is controlled by NF-κB, which is activated by PARP1 upon replication stress. In parallel, inflammatory cytokine gene expression is induced through the NF-κB-PARP1 axis upon nonblocking replication stress. Increasing replication stress intensity accumulates DNA double-strand breaks and triggers the suppression of RIR by p53 and ATM. These data underline the fine-tuning of the cellular response to stress that protects genome stability maintenance, showing that primary cells adapt their responses to replication stress severity.

Srsf2P95H/+ co-operates with loss of TET2 to promote myeloid bias and initiate a chronic myelomonocytic leukemia-like disease in mice

Recurrent mutations in RNA splicing proteins and epigenetic regulators contribute to the development of myelodysplastic syndrome (MDS) and related myeloid neoplasms. In chronic myelomonocytic leukemia (CMML), SRSF2 mutations occur in ~50% of patients and TET2 mutations in ~60%. Clonal analysis indicates that either mutation can arise as the founder lesion. Based on human cancer genetics we crossed an inducible Srsf2P95H/+ mutant model with Tet2fl/fl mice to mutate both concomitantly in hematopoietic stem cells. At 20-24 weeks post mutation induction, we observed subtle differences in the Srsf2/Tet2 mutants compared to either single mutant. Under conditions of native hematopoiesis with aging, we see a distinct myeloid bias and monocytosis in the Srsf2/Tet2 mutants. A subset of the compound Srsf2/Tet2 mutants display an increased granulocytic and distinctive monocytic proliferation (myelomonocytic hyperplasia), with increased immature promonocytes and monoblasts and binucleate promonocytes. Exome analysis of progressed disease demonstrated mutations in genes and pathways similar to those reported in human CMML. Upon transplantation, recipients developed leukocytosis, monocytosis, and splenomegaly. We reproduce Srsf2/Tet2 co-operativity in vivo, yielding a disease with core characteristics of CMML, unlike single Srsf2 or Tet2 mutation. This model represents a significant step toward building high fidelity and genetically tractable models of CMML.

Decitabine Versus Hydroxyurea for Advanced Proliferative Chronic Myelomonocytic Leukemia: Results of a Randomized Phase III Trial Within the EMSCO Network

PURPOSE

Hydroxyurea (HY) is a reference treatment of advanced myeloproliferative neoplasms. We conducted a randomized phase III trial comparing decitabine (DAC) and HY in advanced myeloproliferative chronic myelomonocytic leukemias (CMML).

PATIENTS AND METHODS

Newly diagnosed myeloproliferative CMML patients with advanced disease were randomly assigned 1:1 to intravenous DAC (20 mg/m2/d days 1-5) or HY (1-4 g/d) in 28-day cycles. The primary end point was event-free survival (EFS), events being death and acute myelomonocytic leukemia (AML) transformation or progression.

RESULTS

One-hundred seventy patients received DAC (n = 84) or HY (n = 86). Median age was 72 and 74 years, and median WBC count 32.5 × 109/L and 31.2 × 109/L in the DAC and HY arms, respectively. Thirty-three percent of DAC and 31% of HY patients had CMML-2. Patients received a median of five DAC and six HY cycles. With a median follow-up of 17.5 months, median EFS was 12.1 months in the DAC arm and 10.3 months in the HY arm (hazard ratio [HR], 0.83; 95% CI, 0.59 to 1.16; P = .27). There was no significant interaction between treatment effect and blast or platelet count, anemia, CMML Prognostic Scoring System, Groupe Francophone des Myelodysplasies, or CMML Prognostic Scoring System–mol risk. Fifty-three (63%) DAC patients achieved a response compared with 30 (35%) HY patients ( P = .0004). Median duration of response was similar in both arms (DAC, 16.3 months; HY, 17.4 months; P = .90). Median overall survival was 18.4 months in the DAC arm and 21.9 months in the HY arm ( P = .67). Compared with HY, DAC significantly reduced the risk of CMML progression or transformation to acute myelomonocytic leukemia (cause-specific HR, 0.62; 95% CI, 0.41 to 0.94; P = .005) at the expense of death without progression or transformation (cause-specific HR, 1.55; 95% CI, 0.82 to 2.9; P = .04).

CONCLUSION

Compared with HY, frontline treatment with DAC did not improve EFS in patients with advanced myeloproliferative CMML (ClinicalTrials.gov identifier: NCT02214407 ).

[Incidence and clinical significance of platelet transfusion refractoriness after allogeneic hematopoietic stem cell transplantation in patients with chronic myelomonocytic leukemia]

Objective: To retrospectively analyze the incidence and clinical significance of platelet transfusion refractoriness (PTR) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with chronic myelomonocytic leukemia (CMML) . Methods: A cohort of 55 CMML patients received allo-HSCT at Peking University Institute of Hematology during 2004-2021 were retrospectively assessed. The incidence of PTR within 30 days after allo-HSCT was retrospectively analyzed, and the impact on clinical outcomes and bleeding event were compared between patients with platelet transfusion refractoriness (PTR) or effective platelet transfusion (EPT) . Results: The incidence of PTR after allo-HSCT in CMML patients was 25.5% (14/55) . PTR patients had a lower rate of platelet engraftment than EPT patients (28.6% vs 100%) , and the median time of engraftment was 67 (33-144) days and 21 (9-157) days respectively (P<0.010) . There was no significant difference between two groups in acute graft-versus-host disease (aGVHD) and chronic graft-versus-host disease (cGVHD) (P=0.183, P=0.455) . After following-up a median of 684 (24-3978) days, the 1-year overall survival (OS) and 1-year leukemia free survival (LFS) in PTR and EPT patients were (35.4±13.9) % vs (75.1±7.8) % (P=0.037) and (28.1±13.3) % vs (65.3±8.2) % (P=0.072) , respectively. The transplant-related mortality (TRM) were (48.2±2.4) % and (9.0±0.25) %, respectively (P=0.009) . Bleeding events occurred in five patients (35.7%) of PTR and 2 patients (4.9%) of EPT (P=0.009) . Conclusion: In CMML patients with allo-HSCT, the incidence of PTR is 25.5%, which was associated with delayed platelet engraftment, increased bleeding events, inferior OS and increased TRM.

Real-World Data on Chronic Myelomonocytic Leukemia: Clinical and Molecular Characteristics, Treatment, Emerging Drugs, and Patient Outcomes

Despite emerging molecular information on chronic myelomonocytic leukemia (CMML), patient outcome remains unsatisfactory and little is known about the transformation to acute myeloid leukemia (AML). In a single-center cohort of 219 CMML patients, we explored the potential correlation between clinical features, gene mutations, and treatment regimens with overall survival (OS) and clonal evolution into AML. The most commonly detected mutations were TET2, SRSF2, ASXL1, and RUNX1. Median OS was 34 months and varied according to age, cytogenetic risk, FAB, CPSS and CPSS-Mol categories, and number of gene mutations. Hypomethylating agents were administered to 37 patients, 18 of whom responded. Allogeneic stem cell transplantation (alloSCT) was performed in 22 patients. Two-year OS after alloSCT was 60.6%. Six patients received targeted therapy with IDH or FLT3 inhibitors, three of whom attained a long-lasting response. AML transformation occurred in 53 patients and the analysis of paired samples showed changes in gene mutation status. Our real-world data emphasize that the outcome of CMML patients is still unsatisfactory and alloSCT remains the only potentially curative treatment. However, targeted therapies show promise in patients with specific gene mutations. Complete molecular characterization can help to improve risk stratification, understand transformation, and personalize therapy.

Allogeneic Hematopoietic Stem Cell Transplantation for Mixed or Overlap Myelodysplastic/Myeloproliferative Disorders

Chronic myelomonocytic leukemia (CMML) and the remaining, less frequent hybrid, mixed, or overlap myelodysplastic syndromes/myeloproliferative neoplasms (MDSs/MPNs) are difficult to treat neoplastic hematological disorders, exhibiting substantial clinical and prognostic heterogeneity, for which clear therapeutic guidelines or effective treatment options are still missing. CMML has an overall survival ranging from a few months to several years. Although patients with proliferative or dysplastic features may benefit from hydroxyurea and hypomethylating agent treatment, respectively, none of these treatments can establish long-term remission and prevent the inevitable transformation to acute leukemia. Novel targeted treatment approaches are emerging but are still under investigation. Therefore, currently, allogeneic stem cell transplantation (allo-SCT) remains the only treatment modality with a curative potential, but its widespread application is limited, due to significant morbidity and mortality associated with the procedure, especially in the elderly and in patients with comorbidities. Recognition of patient eligibility for allo-SCT is crucial, and the procedure should be addressed to patients with a good performance status without severe comorbidities and mainly to those in intermediate- to high-risk category, with a suitable stem cell donor available. The issues of best timing for performing transplantation, patient and donor eligibility, the type of conditioning regimen, and the outcomes after various allo-SCT procedures are the topics of this review.

A Case of Chronic Myelomonocytic Leukemia Unmasked After Receiving J&J COVID-19 Vaccine

Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell disease that comes under the overlap syndrome (myelodysplastic and myeloproliferative disorders). CMML is characterized by peripheral blood monocytosis and bone marrow dysplasia. The pathogenesis of CMML is poorly understood. Although cytogenetic and molecular abnormalities are common, they are not diagnostic. Herein, we present a rare case of CMML after receiving the J&J COVID-19 vaccine with the rare association of limited scleroderma. Based on the Surveillance, Epidemiology, and End Result (SEER) cancer statistics review 2014-2018, the five-year age-adjusted incidence rate of CMML in both sexes is 0.5/100,000, with greater incidence in males (0.7/100,000) compared to females (0.3/100,000). We emphasize the fact that, based on the previous studies reported, the association of scleroderma with CMML is very rare. Our patient had concomitant CMML and scleroderma, which were unmasked after the patient received the COVID-19 vaccine. Our case suggests the possibility of developing CMML after receiving the J&J COVID vaccine. Immunization has always been a life-saving intervention in history. As the world is foreseeing getting the COVID-19 vaccine, it is essential to report all the possible adverse events for safety monitoring. Physicians should be aware of this unusual complication of the vaccine, and more cases are needed to confirm the association between them.

Monocytosis and its association with clonal hematopoiesis in community-dwelling individuals

Monocytosis associates with a higher frequency of CH with spliceosome and multiple gene mutations, but not isolated DNMT3A/TET2/ASXL1.

Few community-based individuals with monocytosis and CH develop myeloid malignancy (among 166 individuals: n = 4 cases including n = 1 CMML).

Monocytosis may occur in numerous inflammatory conditions but is also the defining feature of chronic myelomonocytic leukemia (CMML). Clonal somatic mutations detectable in CMML may occur with aging in otherwise healthy individuals, so-called “clonal hematopoiesis” (CH). We investigated whether the combination of CH and monocytosis would represent an early developmental stage of CMML. We studied community-dwelling individuals with monocytosis (≥1 × 10⁹/L and ≥10% of leukocytes) in the population-based Lifelines cohort (n = 144 676 adults). The prevalence and spectrum of CH were evaluated for individuals ≥60 years with monocytosis (n = 167 [0.8%]), and control subjects 1:3 matched for age and sex (n = 501). Diagnoses of hematological malignancies were retrieved by linkage to the Netherlands Cancer Registry (NCR). Monocyte counts and the prevalence of monocytosis increased with advancing age. Older individuals with monocytosis more frequently carried CH (50.9% vs 35.5%; P < .001). Monocytosis is associated with enrichment of multiple gene mutations (P = .006) and spliceosome mutations (P = .007) but not isolated mutated DNMT3A, TET2, or ASXL1. Persistent monocytosis over 4 years was observed in 30/102 evaluable individuals and associated with a higher prevalence of CH (63%). Myeloid malignancies, including 1 case of CMML, developed in 4 individuals with monocytosis who all carried CH. In conclusion, monocytosis and CH both occur at an older age and do not necessarily reflect clonal monocytic proliferation. In a fraction of older subjects with monocytosis, CH might constitute early clonal dominance in developing malignant myelomonocytic disease. Mutational spectra deviating from age-related CH require attention.

Real-world data on efficacy and safety of azacitidine therapy in chronic myelomonocytic leukemia in China: results from a multicenter, retrospective study

Chronic myelomonocytic leukemia (CMML) is a rare and aggressive myeloid malignancy with overlapped features of myelodysplastic syndromes/myeloproliferative neoplasms. Azacitidine (AZA), a hypomethylating agent, has been approved for the treatment of CMML in China, but real-world data are limited. Medical records of CMML patients who had received subcutaneously injected AZA were reviewed from January 2018 at five participating sites in China. Response was assessed according to the modified International Working Group (IWG 2006) criteria. Between January 2018 and November 2020, a total of 24 patients with CMML were included with a median age of 63 years. Patients received a median of 3 cycles of AZA treatment (range, 1-8). Overall response rate (ORR) was 37.5% (9 of 24); CR rate, PR rate, and mCR/HI rate were 8.3% (n = 2), 8.3% (n = 2), and 20.8% (n = 5), respectively. At a median duration of follow-up of 14.0 months (range 0.0-22.0 months), the median overall survival (OS) was 23.0 months. Univariate analysis revealed that ≥ 3 cycles of treatment was significantly associated with a higher 1-year OS rate compared with &lt; 3 cycles of AZA treatment. Treatment was generally well-tolerated. The most common (&gt; 10%) AEs were thrombocytopenia (n = 7, 29.2%), pneumonitis (n = 4, 16.7%) and fever (n = 3, 12.5%). This study provides valuable real-life data in China on the treatment schedules, efficacy and safety of AZA in the treatment of CMML.

Approaching First-Line Treatment in Patients With Advanced CMML: Hypomethylating Agents or Cytotoxic Treatment?

Chronic myelomonocytic leukemia (CMML) is a rare clonal haematological malignancy bearing characteristics of both myelodysplastic syndromes and myeloproliferative neoplasms. It primarily affects older people (median age at diagnosis ~72 years). There are many challenges encountered in its treatment. One striking issue is the lack of strong clinical evidence from large randomized clinical trials for treating this disease. Another issue is that patients with CMML have highly variable outcomes with current treatments. Additional challenges include a wider application of current knowledge, an improved understanding of pathogenesis, development of new therapies, and management of refractory cases/disease progression. It is clear that there is still progress to be made. Here, we review the available first-line treatment options for advanced CMML. Emphasis has been placed on choosing between hypomethylating agents and cytotoxic treatments, on the basis on disease-specific and patient-specific characteristics. A proper selection between these two treatments could lead to a better quality of care for patients with CMML.

Increasing recognition and emerging therapies argue for dedicated clinical trials in chronic myelomonocytic leukemia

Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell disorder with overlapping features of myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN). Median overall survival of this aggressive myeloid malignancy is only 2-3 years, with a 15-30% risk of acute leukemic transformation. The paucity of clinical trials specifically designed for CMML has made therapeutic management of CMML patients challenging. As a result, treatment paradigms for CMML patients are largely borrowed from MDS and MPN. The standard of care still relies on hydroxyurea, hypomethylating agents (HMA), and allogeneic stem cell transplantation, this latter option remaining the only potentially curative therapy. To date, approved drugs for CMML treatment are HMA, including azacitidine, decitabine, and more recently the oral combination of decitabine and cedazuridine. However, HMA treatment does not meaningfully alter the natural course of this disease. New treatment approaches for improving CMML-associated cytopenias or targeting the CMML malignant clone are emerging. More than 25 therapeutic agents are currently being evaluated in phase 1 or phase 2 clinical trials for CMML and other myeloid malignancies, often in combination with a HMA backbone. Several novel agents, such as sotatercept, ruxolitinib, lenzilumab, and tagraxofusp have shown promising clinical efficacy in CMML. Current evidence supports the idea that effective treatment in CMML will likely require combination therapy targeting multiple pathways, which emphasizes the need for additional new therapeutic options. This review focuses on recent therapeutic advances and innovative treatment strategies in CMML, including global and molecularly targeted approaches. We also discuss what may help to make progress in the design of rationally derived and disease-modifying therapies for CMML.

The first description of a singular case of synchronous chronic myelomonocytic leukemia and diffuse large b-cell lymphoma

In CMML, neoplastic monocytes can be distinguished based on their immunophenotype. Supportive care myeloid growth factors in concomitant extranodal non-Hodgkin Lymphoma are safe.

Cytokine-like protein 1-induced survival of monocytes suggests a combined strategy targeting MCL1 and MAPK in CMML

Mouse models of chronic myeloid malignancies suggest that targeting mature cells of the malignant clone disrupts feedback loops that promote disease expansion. Here, we show that in chronic myelomonocytic leukemia (CMML), monocytes that accumulate in the peripheral blood show a decreased propensity to die by apoptosis. BH3 profiling demonstrates their addiction to myeloid cell leukemia-1 (MCL1), which can be targeted with the small molecule inhibitor S63845. RNA sequencing and DNA methylation pattern analysis both point to the implication of the mitogen-activated protein kinase (MAPK) pathway in the resistance of CMML monocytes to death and reveal an autocrine pathway in which the secreted cytokine-like protein 1 (CYTL1) promotes extracellular signal-regulated kinase (ERK) activation through C-C chemokine receptor type 2 (CCR2). Combined MAPK and MCL1 inhibition restores apoptosis of monocytes from patients with CMML and reduces the expansion of patient-derived xenografts in mice. These results show that the combined inhibition of MCL1 and MAPK is a promising approach to slow down CMML progression by inducing leukemic monocyte apoptosis.

Chronic myelomonocytic leukemia diagnosis and management

Chronic myelomonocytic leukemia (CMML) is a rare, heterogeneous myeloid malignancy classified as a myelodysplastic syndromes/myeloproliferative neoplasm (MDS/MPN) overlap syndrome by the World Health Organization (WHO). Its initial presentation can be incidental or associated with myelodysplastic or myeloproliferative symptoms and up to 20% of patients harbor a concurrent inflammatory or autoimmune condition. Persistent monocytosis is the hallmark of CMML but diagnosis can be challenging. Increased understanding of human monocyte subsets, chromosomal abnormalities, and somatic gene mutations have led to more accurate diagnosis and improved prognostication. A number of risk stratification systems have been developed and validated but using those that incorporate molecular information such as CMML Prognostic Scoring System (CPSS)-Mol, Mayo Molecular, and Groupe Francophone des Myelodysplasies (GFM) are preferred. Symptom-directed approaches forms the basis of CMML management. Outcomes vary substantially depending on risk ranging from observation for a number of years to rapidly progressive disease and acute myeloid leukemia (AML) transformation. Patients who are low risk but with symptoms from cytopenias or proliferative features such as splenomegaly may be treated with hypomethylating agents (HMAs) or cytoreductive therapy, respectively, with the goal of durable symptoms control. Allogeneic hematopoietic cell transplantation should be considered for intermediate to high risk patients. The lack of effective pharmaceutical options has generated interest in novel therapeutics for this disease, and early phase clinical trial results are promising.

Contemporary Risk Stratification and Treatment of Chronic Myelomonocytic Leukemia

Chronic myelomonocytic leukemia (CMML) is a hematologic malignancy characterized by absolute monocytosis, one or more lineage dysplasia, and proliferative features including myeloid hyperplasia, splenomegaly, and constitutional symptoms. Because of vast clinical heterogeneity in presentation and course, risk stratification is used for a risk-adapted treatment strategy. Numerous prognostic scoring systems exist, some of which incorporate mutational information. Treatment ranges from observation to allogeneic hematopoietic stem cell transplantation. Therapies include hydroxyurea for cytoreduction, hypomethylating agents, and the JAK1/2 inhibitor ruxolitinib to address splenomegaly and constitutional symptoms. Recently, oral decitabine with cedazuridine was approved and represents a convenient treatment option for CMML patients. Although novel therapeutics are in development for CMML, further work is needed to elucidate possible targets unique to the CMML clone. In this review, we will detail the pathophysiology, risk stratification, available treatment modalities, and novel therapies for CMML, and propose a modern treatment algorithm. IMPLICATIONS FOR PRACTICE: Chronic myelomonocytic leukemia (CMML) is a clinically heterogenous disease, which poses significant management challenges. The diagnosis of CMML requires bone marrow biopsy and aspirate with thorough evaluation. Risk stratification and symptom assessment are essential to designing an effective treatment plan, which may include hypomethylating agents (HMAs) in intermediate or high-risk patients. The recently approved oral decitabine/cedazuridine provides a convenient alternative to parenteral HMAs. Ruxolitinib may be effective in ameliorating proliferative symptoms and splenomegaly. Allogeneic stem cell transplantation remains the only treatment with curative potential; however, novel therapies are in clinical development which may significantly alter the therapeutic landscape of CMML.

Prognostic assessment for chronic myelomonocytic leukemia in the context of the World Health Organization 2016 proposal: a multicenter study of 280 patients

Knowledge on chronic myelomonocytic leukemia (CMML) patients from Argentina and Brazil is limited. Our series of 280 patients depicted an older age at diagnosis (median 72 years old), 26% of aberrant karyotypes, and a prevalence of myelodysplastic (60%) and CMML-0 subtypes (56%). The median overall survival (OS) was 48.2 months for patients in CMML-0 (Ref.), 24.7 months for those in CMML-1 (HR = 2.0, p = 0.001), and 8.8 months for patients in CMML-2 (HR = 4.6, p < 0.001). In the CMML-0 category, median OS were different between myelodysplastic and myeloproliferative subtypes (63.7 vs 21.2 months, p < 0.001); however, no differences were observed within CMML-1 and CMML-2 subtypes (24.7 vs 23.7 months, p = 0.540, and 9.1 vs 8.2 months, p = 0.160). The prognostic impact of 24 variables and 7 prognostic systems was adjusted to the WHO 2016 after validating their usefulness. Multivariate analysis were performed, and the final model revealed Hb ≥ 8 -< 10g/dL (HR 1.7), Hb < 8g/dL (HR 2.8), poor karyotypes (HR 2.1), WHO 2016-CMML-1 (HR 2.1), and CMML-2 (HR 3.5) as independent adverse clinical parameters in our cohort with a borderline influence of platelets count < 50 × 10⁹/L (HR 1.4). We could validate several scoring systems, the WHO 2016 proposal and its prognostic capability, along with accessible covariates, on predicting the outcome in our series of CMML patients from Latin America.

Genetic Aspects of Myelodysplastic/Myeloproliferative Neoplasms

Simple Summary

Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are clonal myeloid neoplasms characterized, at the time of their presentation, by the simultaneous presence of both myelodysplastic and myeloproliferative features. In MDS/MPN, the karyotype is often normal but mutations in genes that are common across myeloid neoplasms can be detected in a high proportion of cases by targeted sequencing. In this review, we intend to summarize the main genetic findings across all MDS/MPN overlap syndromes and discuss their relevance in the management of patients.

Abstract

Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are myeloid neoplasms characterized by the presentation of overlapping features from both myelodysplastic syndromes and myeloproliferative neoplasms. Although the classification of MDS/MPN relies largely on clinical features and peripheral blood and bone marrow morphology, studies have demonstrated that a large proportion of patients (~90%) with this disease harbor somatic mutations in a group of genes that are common across myeloid neoplasms. These mutations play a role in the clinical heterogeneity of these diseases and their clinical evolution. Nevertheless, none of them is specific to MDS/MPN and current diagnostic criteria do not include molecular data. Even when such alterations can be helpful for differential diagnosis, they should not be used alone as proof of neoplasia because some of these mutations may also occur in healthy older people. Here, we intend to review the main genetic findings across all MDS/MPN overlap syndromes and discuss their relevance in the management of the patients.

Expression of mRNA TNFα and level of protein TNFα after exposure sCD40L in bone marrow mononuclear cells of myelodysplastic syndromes

Background

Cytopenia is the primary phenomenon in myelodysplastic syndrome (MDS) amidst hypercellular bone marrow. The soluble CD40 ligand (sCD40L) is considered as a cytokine that can trigger synthesis of tumor necrosis factor α (TNFα) that promotes apoptosis. The objective of this study is to prove that recombinant human sCD40L (rh-sCD40L) exposure on bone marrow mononuclear cells (BMMC) MDS increases TNFα expression at mRNA level and at protein level.

Methods

BMMC from MDS patients whom diagnosed and classified using the WHO 2008 criteria, were exposed to rh-sCD40L and antiCD40L. The expressions of TNFα mRNAs were quantified by qRT-PCR, level of TNFα were measured using the ELISA method.

Results

Exposure of rh-sCD40L significantly increased the expression of TNFα mRNA. The similar exposure also significantly increased the level of TNFα compared to controls. TNFα mRNA expression on BMMC in MDS samples exposed to rh-sCD40L is 3.32 times compared to TNFα mRNA expression without exposure. level of TNFα in supernatant media exposed to rh-sCD40L in MDS samples was higher than that of control samples which were 44.44 and 4.85 pg/mL, P=0.018.

Conclusions

The sCD40L plays a role in increasing the synthesis of TNFα in mRNA level and protein level in BMMC MDS.

Venetoclax/decitabine for a pediatric patient with chronic myelomonocytic leukemia

Chronic myelomonocytic leukemia (CMML) is a myelodysplastic syndrome (MDS)/myeloproliferative disorder most commonly seen in the elderly. We describe an adolescent with monosomy 7 CMML presenting as central diabetes insipidus (DI), who was treated with venetoclax and decitabine as a bridge to hematopoietic stem cell transplantation (HSCT). Central DI is a rare manifestation of monosomy 7-associated MDS including CMML, itself a rare manifestation of GATA2 deficiency, particularly in children. Venetoclax/decitabine was effective for treatment of CMML as a bridge to HSCT.

Chronic myelomonocytic leukemia-associated pulmonary alveolar proteinosis: A case report and review of literature

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a rare condition that can cause progressive symptoms including dyspnea, cough and respiratory insufficiency. Secondary PAP is generally associated with hematological malignancies including chronic myelomonocytic leukemia (CMML). To the best of our knowledge, this is the first reported case of PAP occurring secondary to CMML.

CASE SUMMARY

We report the case of a 63-year-old male who presented with a recurrent cough and gradually progressive dyspnea in the absence of fever. Based upon clinical symptoms, computed tomography findings, bone marrow aspiration, flow cytometry studies and cytogenetic analyses, the patient was diagnosed with PAP secondary to CMML. He underwent whole lung lavage in March 2016 to alleviate his dyspnea, after which he began combined chemotherapeutic treatment with decitabine and cytarabine. The patient died in January 2020 as a consequence of severe pulmonary infection.

CONCLUSION

This case offers insight regarding the mechanistic basis for PAP secondary to CMML and highlights potential risk factors.

Occurrence of a Clonal T-Cell Population in a Case of Chronic Myelomonocytic Leukemia

Chronic myelo-monocytic leukemia (CMML) is an aggressive myeloid neoplasm with some features of a myelodysplastic syndrome (MDS) and others of a myeloproliferative neoplasm (MPN). Rarely, patients with CMML have a co-existing lympho-proliferative disorder (LPD). In most cases, the lymphoid neoplasm is diagnosed first, and the CMML is considered to be a secondary therapy-induced form of leukemia. We report herein a unique case of de-novo CMML, with an underlying clonal T-cell population and describe its clinical presentation and laboratory findings. A 70-year old male presented with a 3-month history of cough, dsypnea, abdominal distension, and low-grade fever. Physical and radiological examination revealed hepatosplenomegaly but no lymphadenopathy. Peripheral blood had absolute monocytosis with marrow showing CMML with 10% blasts along with dysplasia in myeloid and erythroid lineages. Flow cytometry indicated possibility of chronic myelo-monocytic leukemia with 13% monocytic cells along with an additional clonal population of gamma/delta T cells (15%) with aberrant immunophenotype. Polymerase chain reaction (PCR) analysis was positive for clonal T-cell rearrangement. A diagnosis of CMML with an underlying clonal T-CLPD was made. The synchronous occurrence of CMML and T-cell neoplasm may be attributed to a genetic mutation common to both. Currently, there are no treatment guidelines for group of patients; hence individualized therapeutic strategies should be implemented to enable symptomatic improvement and provide optimum care.

Outcomes of patients with chronic myelomonocytic leukaemia treated with non-curative therapies: a retrospective cohort study

BACKGROUND

Approval of hypomethylating agents in patients with chronic myelomonocytic leukaemia is based on trials done in patients with myelodysplastic syndromes. We aimed to investigate whether hypomethylating agents provide a benefit in subgroups of patients with chronic myelomonocytic leukaemia compared with other treatments.

METHODS

For this retrospective cohort study, data were retrieved between Nov 30, 2017, and Jan 5, 2019, from 38 centres in the USA and Europe. We included non-selected, consecutive patients diagnosed with chronic myelomonocytic leukaemia, who received chronic myelomonocytic leukaemia-directed therapy. Patients with acute myeloid leukaemia according to 2016 WHO criteria at initial diagnosis (ie, ≥20% blasts in the bone marrow or peripheral blood) or with unavailability of treatment data were excluded. Outcomes assessed included overall survival, time to next treatment, and time to transformation to acute myeloid leukaemia. Analyses were adjusted by age, sex, platelet count, and Chronic myelomonocytic leukaemia-Specific Prognostic Scoring System (CPSS). Patients were grouped by first received treatment with either hydroxyurea, hypomethylating agents, or intensive chemotherapy, and stratified by risk according to blast count, French-American-British subtype, CPSS, WHO 2016 subtype, and the eligibility criteria of the DACOTA trial (NCT02214407).

FINDINGS

949 patients diagnosed with chronic myelomonocytic leukaemia between April 13, 1981, and Oct 26, 2018, were included. Median follow-up was 23·4 months (IQR 11·5-42·3) from diagnosis and 16·2 months (6·6-31·6) from start of first-line treatment. 412 (43%) of 949 patients received hypomethylating agents as first treatment, 391 (41%) hydroxyurea, and 83 (9%) intensive chemotherapy. Adjusted median overall survival for patients treated with hydroxyurea versus hypomethylating agents was 15·6 months (95% CI 13·1-17·3) versus 20·7 months (17·9-23·4); hazard ratio (HR) 1·39 (1·17-1·65; p=0·0002) and 14·0 months (9·8-17·2) versus 20·7 months (17·9-23·4; HR 1·55 [1·16-2·05]; p=0·0027) for those treated with intensive chemotherapy versus hypomethylating agents. In patients with myeloproliferative chronic myelomonocytic leukaemia (myeloproliferative CMML), median overall survival was 12·6 months (10·7-15·0) versus 17·6 months (14·8-21·5; HR 1·38 [1·12-1·70]; p=0·0027) for patients treated with hydroxyurea versus hypomethylating agents, and 12·3 months (8·4-16·6) versus 17·6 months (14·8-21·5; HR 1·44 [1·02-2·03]; p=0·040) for intensive chemotherapy versus hypomethylating agents. Hypomethylating agents did not confer an overall survival advantage for patients classified as having lower-risk disease (ie, myelodysplastic chronic myelomonocytic leukaemia with <10% blasts, CMML-0, or lower-risk CPSS).

INTERPRETATION

These data suggest hypomethylating agents as the preferred therapy for patients with higher-risk chronic myelomonocytic leukaemia and those with myeloproliferative CMML. Our findings also suggest that CPSS is a valuable tool to identify patients who are most likely to benefit from hypomethylating agents. Further evidence from prospective cohorts would be desirable.

FUNDING

The Austrian Group for Medical Tumor Therapy.

Molecular Pathogenesis and Treatment Perspectives for Hypereosinophilia and Hypereosinophilic Syndromes

Hypereosinophilia (HE) is a heterogeneous condition with a persistent elevated eosinophil count of >350/mm³, which is reported in various (inflammatory, allergic, infectious, or neoplastic) diseases with distinct pathophysiological pathways. HE may be associated with tissue or organ damage and, in this case, the disorder is classified as hypereosinophilic syndrome (HES). Different studies have allowed for the discovery of two major pathogenetic variants known as myeloid or lymphocytic HES. With the advent of molecular genetic analyses, such as T-cell receptor gene rearrangement assays and Next Generation Sequencing, it is possible to better characterize these syndromes and establish which patients will benefit from pharmacological targeted therapy. In this review, we highlight the molecular alterations that are involved in the pathogenesis of eosinophil disorders and revise possible therapeutic approaches, either implemented in clinical practice or currently under investigation in clinical trials.

Curcumol and FTY720 synergistically induce apoptosis and differentiation in chronic myelomonocytic leukemia via multiple signaling pathways

Chronic myelomonocytic leukemia (CML) is a myeloid tumor characterized by MDS (myelodysplastic syndrome) and MPN (myeloproliferative neoplasms). Allogeneic hematopoietic stem cell transplantation, chemotherapy, interferon, and targeted therapy are the main treatment methods for CML. Tyrosine kinase inhibitors (TKIs) are also a treatment option, and patients are currently recommended to take these drugs throughout their lives to prevent CML recurrence. Therefore, there is a need to investigate and identify other potential chemotherapy drugs. Currently, research on CML treatment with a single drug has shown little progress. Fingolimod (FTY720), an FDA-approved drug used to treat relapsing multiple sclerosis, has also shown great potential in the treatment of lymphocytic leukemia. In our study, we find that FTY720 and curcumol have a significant inhibitory effect on K562 cells, K562/ADR cells, and CD34⁺ cells from CML patients. RNAseq data analysis shows that regulation of apoptosis and differentiation pathways are key pathways in this process. Besides, BCR/ABL-Jak2/STAT3 signaling, PI3K/Akt-Jnk signaling, and activation of BH3-only genes are involved in CML inhibition. In a K562 xenograft mouse model, therapy with curcumol and FTY720 led to significant inhibition of tumor growth and induction of apoptosis. To summarize, curcumol and FTY720 synergistically inhibit proliferation involved in differentiation and induce apoptosis in CML cells. Therefore, synergistic treatment with two drugs could be the next choice of treatment for CML.

Successful long-term treatment with azacitidine in patient with chronic myelomonocytic leukemia

The purpose of this article was to present a case of successful long term treatment with azacitidine in patient with Chronic Myelomonocytic Leukemia (CMML) and discussing possible contributing factors for its long term efficacy. Data from our case were compared with similar data available in the literature. Effective treatment with azacitidine resulted in overall survival of 11 years 5 months and we showed that applying multiple cycles of treatment is feasible. Our patient received 71 cycles of treatment with total duration of 7 years and 3 months. Our report about a patient with CMML and a good clinical course revealed, that long term treatment with azacitidine is feasible in some patients. Initially low bone marrow blast count, a relatively small malignant CMML clone, reduction of spleen size and fast platelet response seemed to be factors determining long term response to treatment in our patient. More data on CMML treatment by Hypomethylating Agents and their analysis are needed in order to make firm conclusions.

Acquired Pure Red Cell Aplasia Associated with Chronic Myelomonocytic Leukemia: Too Many of One, Not Enough of the Other

There is a growing body of literature outlining the association between certain hematological malignancies, such as chronic myelomonocytic leukemia (CMML), and systemic autoimmune diseases. Diagnosis and management can be difficult, particularly when autoimmune phenomena overlap with features of the underlying illness. This is especially the case in patients who develop immune-mediated cytopenias in the context of underlying bone marrow disease. CMML associated with immune thrombocytopenia and hemolytic anemia has been reported a number of times in the literature; however, there are only scattered case reports describing CMML associated with acquired pure red cell aplasia. Here, we describe the diagnostic and management approach to a patient who developed both diseases.

Coombs-positive refractory acquired thrombotic thrombocytopenic purpura in a patient with chronic myelomonocytic leukemia successfully treated with rituximab

OBJECTIVES

Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare autoimmune disorder characterized by auto-antibodies to Willebrand factor (vWF) cleaving enzyme (ADAMTS13), resulting in unusually large vWF multimers that lead to platelet aggregation, microthrombi formation and microangiopathic hemolytic anemia. Hemolysis in aTTP is mechanical; thus, direct antiglobulin test (Coombs test) is usually negative. Multiple autoimmune conditions and various auto-antibodies have been described in the context of chronic myelomonocytic leukemia (CMML). In this paper, we describe the first case of CMML with auto-antibodies to ADAMTS13, presenting initially as plasmapheresis-refractory Coombs-positive aTTP. Results: Although our patient was not treated for CMML, a complete remission of aTTP was eventually achieved with rituximab. Conclusion; We propose that aTTP should be in the differential diagnosis of CMML patients with thrombocytopenia and anemia (Coombs positive or not) who develop signs of thrombotic microangiopathy. Further studies are much needed to decipher the immune-mediated processes in CMML.

Proliferative activity is disturbed in myeloproliferative neoplasms (MPN), myelodysplastic syndrome (MDS), and MDS/MPN diseases. Differences between MDS and MDS/MPN

The proliferation marker Ki-67 is widely used within the field of diagnostic histopathology as a prognostic marker for solid cancers. However, Ki-67 is hardly used for prognostic and diagnostic purposes in flow cytometric analyses of hematologic neoplasms. In the present study, we investigated to what extent the proliferative activity, as determined by Ki-67 expression, is disturbed in myeloproliferative neoplasms (MPN), myelodysplastic syndrome (MDS), and MDS/MPN diseases. Bone marrow aspirates from 74 patients suffering from MPN, MDS, or MDS/MPN, and aspirates from 50 non-malignant cases were analyzed by flow cytometry for Ki-67 expression in the erythro-, myelo-, and monopoiesis. Ki-67 expression was used to investigate the proliferative activity during the various maturation steps within these hematopoietic cell lineages. In the MPN patient cohort, the proliferative activity of all cell lineages is significantly higher during almost all maturation stages compared to those of the benign control cohort. In the MDS and MDS/MPN cohort, a significantly lower proliferative activity is observed in the early maturation stages. In the MDS/MPN patient cohort, increased proliferative activity is seen in the later stages of the maturation. MDS and MDS/MPN display a distinct pattern in the proliferating fraction of maturing hematopoietic cells. This could become of added value in order to classify these malignancies based on their biological background and behavior, as well as in gaining a better understanding into the pathobiology of these malignancies.

The transcriptome of CMML monocytes is highly inflammatory and reflects leukemia-specific and age-related alterations

Chronic myelomonocytic leukemia (CMML) is an aggressive myeloid neoplasm of older individuals characterized by persistent monocytosis. Somatic mutations in CMML are heterogeneous and only partially explain the variability in clinical outcomes. Recent data suggest that cardiovascular morbidity is increased in CMML and contributes to reduced survival. Clonal hematopoiesis of indeterminate potential (CHIP), the presence of mutated blood cells in hematologically normal individuals, is a precursor of age-related myeloid neoplasms and associated with increased cardiovascular risk. To isolate CMML-specific alterations from those related to aging, we performed RNA sequencing and DNA methylation profiling on purified monocytes from CMML patients and from age-matched (old) and young healthy controls. We found that the transcriptional signature of CMML monocytes is highly proinflammatory, with upregulation of multiple inflammatory pathways, including tumor necrosis factor and interleukin (IL)-6 and -17 signaling, whereas age per se does not significantly contribute to this pattern. We observed no consistent correlations between aberrant gene expression and CpG island methylation, suggesting that proinflammatory signaling in CMML monocytes is governed by multiple and complex regulatory mechanisms. We propose that proinflammatory monocytes contribute to cardiovascular morbidity in CMML patients and promote progression by selection of mutated cell clones. Our data raise questions of whether asymptomatic patients with CMML benefit from monocyte-depleting or anti-inflammatory therapies.

Improving the accuracy of prognostication in chronic myelomonocytic leukemia

INTRODUCTION

Chronic myelomonocytic leukemia (CMML) is a hematological malignancy that is extremely variable regarding its clinical course. It may present either as a chronic disorder with mild symptoms and low disease burden for several years, thereby justifying a watch-and-wait-strategy, or may soon progress to acute myeloid leukemia (AML) leaving allogeneic stem cell transplantation as the only curative treatment option.

AREAS COVERED

Attempts have been made to integrate clinical, cytogenetic, and molecular parameters into scoring systems aiming at providing reliable prognostic information. In this article, we discuss several prognostic parameters and validate prognostic scores in a cohort of 645 patients with CMML.

EXPERT OPINION

We show that the CPSS (CMML prognostic scoring system) is a useful prognostic tool. The integration of molecular data into the new CPSS-mol will further improve prognostic accuracy, primarily by identifying an increased proportion of higher-risk patients.

Chronic myelomonocytic leukaemia stem cell transcriptomes anticipate disease morphology and outcome

BACKGROUND

Chronic myelomonocytic leukaemia (CMML) is a clinically heterogeneous stem cell malignancy with overlapping features of myelodysplasia and myeloproliferation. Over 90% of patients carry mutations in epigenetic and/or splicing genes, typically detectable in the Lin-CD34+CD38- immunophenotypic stem cell compartment in which the leukaemia-initiating cells reside. Transcriptional dysregulation at the stem cell level is likely fundamental to disease onset and progression.

METHODS

We performed single-cell RNA sequencing on 6826 Lin-CD34+CD38-stem cells from CMML patients and healthy controls using the droplet-based, ultra-high-throughput 10x platform.

FINDINGS

We found substantial inter- and intra-patient heterogeneity, with CMML stem cells displaying distinctive transcriptional programs. Compared with normal controls, CMML stem cells exhibited transcriptomes characterized by increased expression of myeloid-lineage and cell cycle genes, and lower expression of genes selectively expressed by normal haematopoietic stem cells. Neutrophil-primed progenitor genes and a MYC transcription factor regulome were prominent in stem cells from CMML-1 patients, whereas CMML-2 stem cells exhibited strong expression of interferon-regulatory factor regulomes, including those associated with IRF1, IRF7 and IRF8. CMML-1 and CMML-2 stem cells (stages distinguished by proportion of downstream blasts and promonocytes) differed substantially in both transcriptome and pseudotime, indicating fundamentally different biology underpinning these disease states. Gene expression and pathway analyses highlighted potentially tractable therapeutic vulnerabilities for downstream investigation. Importantly, CMML patients harboured variably-sized subpopulations of transcriptionally normal stem cells, indicating a potential reservoir to restore functional haematopoiesis.

INTERPRETATION

Our findings provide novel insights into the CMML stem cell compartment, revealing an unexpected degree of heterogeneity and demonstrating that CMML stem cell transcriptomes anticipate disease morphology, and therefore outcome.

FUNDING

Project funding was supported by Oglesby Charitable Trust, Cancer Research UK, Blood Cancer UK, and UK Medical Research Council.

[Impact of splenomegaly on outcomes of allogeneic hematopoietic stem cell transplantation in patients with chronic myelomonocytic leukemia]

目的

探讨脾肿大对慢性粒-单核细胞白血病（CMML）异基因造血干细胞移植（allo-HSCT）预后的影响。

方法

对2004年至2018年在北京大学血液病研究所接受allo-HSCT后的25例CMML患者进行回顾性分析，根据预处理前2周是否伴有脾脏肿大分为脾肿大组和非脾肿大组，比较两组患者在植入、移植物抗宿主病（GVHD）、复发以及生存方面的差异。

结果

①脾肿大组15例（男8例，女7例），中位年龄45（23~61）岁；非脾肿大组10例（男、女各5例），中位年龄39（12~56）岁。两组患者基线特征差异无统计学意义（P>0.05）。②脾肿大组、非脾肿大组粒细胞植入率分别为93.3%（14/15）、100.0%（10/10），中位植入时间分别为17（11~20）d、14（11~18）d（χ²=5.303，P=0.021）；脾肿大组、非脾肿大组血小板植入率分别为80.0%（12/15）、90.0%（9/10）（P=0.212），中位植入时间分别为17（12~33）d、15（12~19）d（χ²=0.470，P=0.493）。③脾肿大组5例发生急性GVHD（Ⅰ/Ⅱ度4例，Ⅲ/Ⅳ度1例），非脾肿大组6例发生急性GVHD（Ⅰ/Ⅱ度5例，Ⅲ/Ⅳ度1例）（χ²=0.204，P=0.652）。脾肿大组、非脾肿大组移植后100 d的急性GVHD累积发生率分别为33.3%（95%CI 14.9%~51.7%）、20.0%（95%CI 2.8%~37.2%）（P=0.635）。脾肿大组5例发生慢性GVHD（广泛型3例），非脾肿大组未发生慢性GVHD（P=0.041）。④脾肿大组、非脾肿大组3年累积复发率分别为（42.7±2.6）%、（11.1±1.2）%（χ²=1.824，P=0.122），3年总生存率分别为（61.5±13.5）%、（68.6±15.1）%（χ²=0.351，P=0.554），3年无白血病生存率分别为（56.3±14.8）%、（80.0±17.9）%（χ²=1.148，P=0.284）。

结论

脾肿大可致CMML患者allo-HSCT后粒细胞植入延迟，对生存及复发无影响。

Leukemoid reaction in chronic myelomonocytic leukemia patients undergoing surgery: perioperative management recommendations

CMML patients comprise an elderly and frail patient population with comorbidities that often require surgical intervention. Postsurgical leukemoid reaction, a life-threatening complication in CMML patients, may be driven by molecular mechanisms.

Chronic Myelomonocytic Leukemia: 2018 Update to Prognosis and Treatment

PURPOSE OF REVIEW

Chronic myelomonocytic leukemia (CMML) is a rare and often aggressive myeloid malignancy. Historically, prognostic markers and therapeutic paradigms have been applied from myelodysplastic syndromes (MDS) or myeloproliferative neoplasms (MPNs). Interest has increased recently in developing tailored approaches for the MDS/MPN overlap syndrome of CMML.

RECENT FINDINGS

Multiple prognostic scores have been validated specifically for CMML in the past 5 years. These incorporate somatic mutations, with ASXL1 mutations repeatedly correlating with poor prognosis. Accurate prognostication can guide treatment. Hypomethylating agents (HMAs) and curative allogeneic blood or marrow transplantation (BMT) remain the most available standard treatments. Recently, a number of novel approaches using unapproved therapies (i.e., lenalidomide, ruxolitinib, sotatercept, and tipifarnib) have demonstrated some efficacy in CMML. Increased recognition and interest in CMML have led to the development of a number of new prognostic models and potential treatment options. Standard treatment options remain limited and clinical trials should be strongly considered whenever available.

Contemporary treatment approaches to CMML - Is allogeneic HCT the only cure?

Chronic Myelomonocytic Leukemias are frequently diagnosed in older adults. Their prognosis is heterogeneous, but several prognostic factors can identify patients with an expected survival of a few years only, including among younger patients eligible for allogeneic stem cell transplantation. Based on the retrospective data available, we discuss how to identify CMML patients for whom curative therapy must be envisaged. We emphasize that, although transplantation remains the only path to cure in CMML, it can be envisaged in only a minority of patients. Despite increased donor availability, its potential remains limited by significant rates of mortality caused both by the procedure and by post-transplantation relapses. We review the options available to bridge patients to transplant, the management of transplantation itself (choice of donor, graft source and condition regimen), and finally the potential for post-transplantation interventions. Our review underscores the need for further prospective studies of allogeneic stem cell transplantation in CMML.

Antidepressive properties of macrophage-colony stimulating factor in a mouse model of depression induced by chronic unpredictable stress

Previous studies have reported that macrophage-colony stimulating factor (M-CSF), a drug that is used to treat hematological system disease, can ameliorate chronic stress-induced depressive-like behaviors in mice. This indicates that M-CSF could be developed into a novel antidepressant. Here, we investigated the antidepressive properties of M-CSF, aiming to explore its potential values in depression treatment. Our results showed that a single M-CSF injection at the dose of 75 and 100 μg/kg, but not at 25 or 50 μg/kg, ameliorated chronic unpredictable stress (CUS)-induced depressive-like behaviors in mice at 5 h after the drug treatment. In a time-dependent experiment, a single M-CSF injection (100 μg/kg) was found to ameliorate the CUS-induced depressive-like behaviors in mice at 5 and 8 h, but not at 3 h, after the drug treatment. The antidepressant effect of the single M-CSF injection (100 μg/kg) in chronically-stressed mice persisted at least 10 days and disappeared at 14 days after the drug treatment. Moreover, 14 days after the first injection, a second M-CSF injection (100 μg/kg) still produced antidepressant effects at 5 h after the drug treatment in chronically-stressed mice who re-displayed depressive-like phenotypes. The antidepressant effect of M-CSF appeared to be mediated by the activation of the hippocampal microglia, as pre-inhibition of microglia by minocycline (40 mg/kg) or PLX3397 (290 mg/kg) pretreatment prevented the antidepressant effect of M-CSF in CUS mice. These results demonstrate that M-CSF produces rapid and sustained antidepressant effects via the activation of the microglia in the hippocampus in a dose- and time-dependent manner.