Prognosis Of Chronic Myelomonocytic Leukemia Research Articles

P122 - Topic: AS07-Singular Entities/Subtypes/AS07e-Chronic myelomonocytic leukemia and overlap syndromes (MDS/MPN): TET2/SRSF2 STATUS AND THROMBOSIS ARE RELEVANT FOR PROGNOSIS IN CHRONIC MYELOMONOCYTIC LEUKEMIA –DATA FROM A POPULATION-BASED STUDY OF 155 PATIENTS

P122 - Topic: AS07-Singular Entities/Subtypes/AS07e-Chronic myelomonocytic leukemia and overlap syndromes (MDS/MPN): TET2/SRSF2 STATUS AND THROMBOSIS ARE RELEVANT FOR PROGNOSIS IN CHRONIC MYELOMONOCYTIC LEUKEMIA –DATA FROM A POPULATION-BASED STUDY OF 155 PATIENTS

Asxl1 loss cooperates with oncogenic Nras in mice to reprogram the immune microenvironment and drive leukemic transformation

AbstractMutations in chromatin regulator ASXL1 are frequently identified in myeloid malignancies, in particular ∼40% of patients with chronic myelomonocytic leukemia (CMML). ASXL1 mutations are associated with poor prognosis in CMML and significantly co-occur with NRAS mutations. Here, we show that concurrent ASXL1 and NRAS mutations defined a population of CMML patients who had shorter leukemia-free survival than those with ASXL1 mutation only. Corroborating this human data, Asxl1−/− accelerated CMML progression and promoted CMML transformation to acute myeloid leukemia (AML) in NrasG12D/+ mice. NrasG12D/+;Asxl1−/− (NA) leukemia cells displayed hyperactivation of MEK/ERK signaling, increased global levels of H3K27ac, upregulation of Flt3. Moreover, we find that NA-AML cells overexpressed all the major inhibitory immune checkpoint ligands: programmed death-ligand 1 (PD-L1)/PD-L2, CD155, and CD80/CD86. Among them, overexpression of PD-L1 and CD86 correlated with upregulation of AP-1 transcription factors (TFs) in NA-AML cells. An AP-1 inhibitor or short hairpin RNAs against AP-1 TF Jun decreased PD-L1 and CD86 expression in NA-AML cells. Once NA-AML cells were transplanted into syngeneic recipients, NA-derived T cells were not detectable. Host-derived wild-type T cells overexpressed programmed cell death protein 1 (PD-1) and T-cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT) receptors, leading to a predominant exhausted T-cell phenotype. Combined inhibition of MEK and BET resulted in downregulation of Flt3 and AP-1 expression, partial restoration of the immune microenvironment, enhancement of CD8 T-cell cytotoxicity, and prolonged survival in NA-AML mice. Our study suggests that combined targeted therapy and immunotherapy may be beneficial for treating secondary AML with concurrent ASXL1 and NRAS mutations.

Prognostic Role of Gene Mutations in Chronic Myelomonocytic Leukemia (CMML) Patients Treated with Hypomethylating Agents. a Report on 183 Patients

Context: Somatic gene mutations contribute to the heterogeneous prognosis of CMML. The hypomethylating agents (HMA) azacitidine (AZA) and decitabine (DAC) are active in CMML. The specific prognostic value of recurrent gene mutations in CMML treated with HMA has never been reported. Methods: We analyzed a multi-institution retrospective cohort of 183 CMML patients (pts) treated with either AZA or DAC with information on recurrent gene mutations. Results: CMML pts with a median age of 72 years (WHO 2016: CMML-0/1/2 in 37%, 27% and 36% respectively [resp]) were treated with AZA (n=76) or DAC (n=107) for a median of 7 cycles (InterQuartile Range [IQR]: 4 - 15). Median WBC was 15.1 x109/L, cytogenetic risk according to CPSS (Such et al, Haematologica 2011) was low, int and high in 71%, 12% and 17% of pts, resp. CPSS risk (Such et al, Blood 2013) was low, int-1, int-2 and high in 14%, 23%, 49% and 14%, resp. GFM risk (Itzykson et al, JCO 2013) was low, int and high in 33%, 35% and 32%, resp. The Overall Response Rate (ORR) to HMA was 54%, including 17% of complete responses (CR), without significant differences between AZA and DAC. With a median follow-up of 36.7 months, median overall (OS) and AML-free (AMLFS) survival were 24.4 and 19.2 months, resp. Nineteen (10%) pts were transplanted after HMA and censoring at transplant did not affect our results. Compared to AZA pts, DAC pts had higher WBC (p=0.01) and non-significant trends towards lower platelet count (p=0.07) and poorer cytogenetic risk (p=0.08), with a non-significant trend to a poorer OS (p=0.11). Propensity matching on previous treatment with chemotherapy, WBC, platelets count, peripheral blasts count, cytogenetic risk and ASXL1 status at HMA onset confirmed the lack of OS benefit with AZA in the 144 patients (79%) that could be successfully matched (Hazard Ratio [HR]=1.31, p=0.4). All further analyses were nevertheless stratified on HMA. Molecular data was obtained from Sanger sequencing (n=74) or NGS (n=109). The molecular spectrum of our cohort was comparable to previous CMML reports and dominated by frequent mutations in SRSF2 (46%), ASXL1 (45%) and TET2 (39%). Our analysis focused on genes analyzed in ≥90% of patients and found mutated in ≥10% (SRSF2, ASXL1, TET2, NRAS, RUNX1 and CBL). Mutation frequencies in these genes did not differ between AZA and DAC pts, nor between Sanger and NGS. In univariate analysis, a lower ORR was only seen in patients with ASXL1 mutations (ASXL1mut 44% vs ASXL1wt 62%, p=0.02) while only TET2 mutations predicted a higher CR rate (TET2mut 22% vs TET2wt 11%, p=0.02). Multivariate linear regressions confirmed that these differences were independent from clinical parameters. In univariate analysis, mutations in RUNX1 (13% of pts, HR=2.05, p=0.006) and to a lesser extent ASXL1 (45% of pts, HR=1.40, p=0.07) and CBL (12% of pts, HR=1.63, p=0.08) were associated with shorter OS. Similar results were found for AMLFS. There was no significant interaction between TET2 and ASXL1 or SRSF2 status in terms of ORR or OS. Clinical variables associated with poorer OS included splenomegaly (p=0.045), WBC > 13 x 109/L (p=0.003), platelets 2% (p=0.02), peripheral blasts > 1% (p=0.02) and high-risk karyotype (p=0.047). A multivariate Cox model retained RUNX1 mutations (p=0.007), splenomegaly (p=0.049), WBC > 13 x 109/L (p=0.005), platelets Conclusion: Contrary to previous results with smaller patient numbers (Braun et al Blood 2011), treatment with HMA seems to abrogate only partially the poor prognosis of ASXL1 mutations in CMML. RUNX1 mutations confer a poor prognosis in CMML treated with HMA and can be integrated with clinical and hematological parameters to improve prognostication of CMML pts treated with HMA, when compared with classical CMML risk scores. Disclosures Sallman: Celgene: Research Funding. Coombs: Pharmacyclics: Honoraria; H3 Biomedicine: Honoraria. Renneville: CELGENE: Research Funding. Platzbecker: Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Research Funding; Acceleron: Consultancy, Honoraria, Research Funding. Padron: Incyte: Honoraria, Research Funding. Santini: Celgene: Honoraria, Research Funding; Abbvie: Consultancy, Membership on an entity9s Board of Directors or advisory committees; Janssen: Consultancy, Honoraria; Amgen: Membership on an entity9s Board of Directors or advisory committees; Otsuka: Consultancy; Novartis: Honoraria. Fenaux: Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Astex: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Astex: Honoraria, Research Funding; Janssen: Honoraria, Research Funding. Itzykson: Janssen: Research Funding; Novartis: Research Funding.

Mutations in chronic myelomonocytic leukemia and their prognostic relevance.

Chronic myelomonocytic leukemia (CMML) is a hematologic malignancy that overlaps with myeloproliferative neoplasms (MPN) and myelodysplastic syndromes (MDS) and tends to transform into acute myeloid leukemia (AML). Among cases of CMML, > 90% have gene mutations, primarily involving TET2 (~ 60%), ASXL1 (~ 40%), SRSF2 (~ 50%), and the RAS pathways (~ 30%). These gene mutations are associated with both the clinical phenotypes and the prognosis of CMML, special CMML variants and pre-phases of CMML. Cytogenetic abnormalities and the size of genome are also associated with prognosis. Meanwhile, cases with ASXL1, DNMT3A, NRAS, SETBP1, CBL and RUNX1 mutations may have inferior prognoses, but only ASXL1 mutations were confirmed to be independent predictors of the patient outcome and were included in three prognostic models. Novel treatment targets related to the various gene mutations are emerging. Therefore, this review provides new insights to explore the correlations among gene mutations, clinical phenotypes, prognosis, and novel drugs in CMML.

Transcriptomic Features and Deregulation of Genes Involved in Monopoiesis Influence Outcomes of Patients with Chronic Myelomonocytic Leukemia

INTRODUCTION: Chronic myelomonocytic leukemia (CMML) is characterized by TET2, SRSF2, ASXL1 and RAS pathway mutations known to induce myelomonocytic bias. We have previously shown that upregulation of KDM6B, a histone demethylase that acts as an innate immune signal activator, leads to myeloid bias and expansion of immature myelomonocytic precursors and LSK cells in mice, resulting in rapid development of a myeloproliferative CMML (MP-CMML) phenotype particularly in cooperation with TET2 deletion. However, the role of genes involved in innate immunity regulation and monocyte differentiation in CMML phenotype and outcomes remains unclear. METHODS: We evaluated bone marrow aspirates from 19 patients with CMML and compared their transcriptomic features to those of healthy individuals obtained from AllCells (Emeryville, CA). CD34+ cells were isolated using the CD34 MicroBead Kit and RNA was isolated using the PicoPure RNA isolation kit. Fastq files were mapped to the human genome (build GRCh38) in TopHat2 using the default options. Differential gene expression analysis was conducted using DESeq2 in R version 3.4.2. Pathway enrichment analysis was performed using gene set enrichment analysis, with the fgsea library in R. Genes were ranked according to their Spearman correlation with the gene of interest, and this ranking was used as the input to fgsea. 10 000 gene permutations were used to calculate statistical significance, and a false discovery corrected p-value of 0.05 was required for statistical significance of a gene set. Cox regression and time ROC curves were used to study the relationship between gene expression and survival. We implemented Kaplan-Meier estimator along with optimum cutoff method to show the survival behavior in high versus low predicted model groups. RESULTS: Compared to healthy controls, a total of 1495 genes had significantly differential expression in CMML (q<0.05, FC>2) including 1271 genes which were significantly upregulated, and 224 which were significantly downregulated in CMML (Figure 1A). Gene set enrichment analysis identified 162 gene sets with differential expression in CMML compared to control (q<0.05). Top upregulated genes were associated with interferon (IFN) alpha and beta signaling, chemokine receptors, IFN-gamma, GPC receptor ligand signaling and genes involved in immunomodulatory interactions between lymphoid and non-lymphoid cells (Figure 1B). Unsupervised clustering of gene expression profiles did not discriminate MP-CMML from myelodysplastic (MD-CMML). However, 20 genes were significantly overexpressed and 16 were significantly downregulated in patients with MP-CMML compared to MD-CMML (q<0.05, FC>2). In addition, 6 gene sets were differentially upregulated and 139 were significantly downregulated in pts with MP-CMML compared to MD-CMML (Figure 1C). To evaluate aberrant monopoiesis in CMML, we compared the expression of genes reported to be involved in regulation of monopoiesis among healthy controls and patients with CMML. A total of 23 genes involved in regulation of monopoiesis were found to be upregulated in CMML (Figure 1D). No significant differences in expression of these genes was found between MP-CMML and MD-CMML. To determine if aberrant expression of genes involved in monopoiesis influenced outcomes of pts with CMML, we developed a prediction model using Cox regression including 18 of these genes. Use of this model with optimum cutoffs allowed segregation of pts into two prognostic subsets with distinct survival outcomes (Figure 1E). Use of ROC curves identified high AUC particularly in pts with prolonged survival (>40 months). CONCLUSIONS: CMML is characterized by upregulation of IFN and chemokine receptor signaling which could represent potential therapeutic targets. Aberrant expression of genes involved in regulation of monopoiesis may influence prognosis in CMML. Figure Disclosures Sasaki: Otsuka: Honoraria; Pfizer Japan: Consultancy; Daiichi Sankyo: Consultancy; Novartis: Consultancy, Research Funding. Kantarjian:Sanofi: Research Funding; Pfizer: Honoraria, Research Funding; Abbvie: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; BMS: Research Funding; Daiichi-Sankyo: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Immunogen: Research Funding; Actinium: Honoraria, Membership on an entity's Board of Directors or advisory committees; Ascentage: Research Funding; Adaptive biotechnologies: Honoraria; Aptitute Health: Honoraria; BioAscend: Honoraria; Delta Fly: Honoraria; Janssen: Honoraria; Oxford Biomedical: Honoraria; Jazz: Research Funding. Garcia-Manero:AbbVie: Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Onconova: Research Funding; Acceleron Pharmaceuticals: Consultancy, Honoraria; H3 Biomedicine: Research Funding; Jazz Pharmaceuticals: Consultancy; Merck: Research Funding; Amphivena Therapeutics: Research Funding; Helsinn Therapeutics: Consultancy, Honoraria, Research Funding; Astex Pharmaceuticals: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding.

Expressions of BAP1 and TET2 proteins in bone marrow of patients with chronic myelomonocytic leukemia and their significances

Objective To investigate the expressions of BAP1 and TET2 proteins in bone marrow of patients with chronic myelomonocytic leukemia (CMML) and their relationship with the prognosis of CMML. Methods The bone marrow paraffin specimens of 41 cases from 41 adult CMML patients diagnosed by Shanghai Sino-US Joint Leukemia Coordination Group from September 2003 to May 2007 were collected. The immunohistochemistry was used to detect the expressions of BAP1 and TET2 proteins in 41 CMML patients. The expressions of TET2 and BAP1 proteins were also detected by the same method in 40 adult patients with acute myelomonocytic leukemia (AMML) and 20 patients with iron deficiency anemia (IDA) diagnosed at the same time as the comparison. The clinical data of 41 CMML patients were analyzed by using retrospective cohort study. The count data were compared by using chi-square test. The correlation between expressions of BAP1 and TET2 proteins was analyzed by using Pearson correlation analysis. Kaplan-Meier method was used to calculate the survival time, and Log-rank test was used for single factor analysis. Results In 41 CMML patients, the positive expression rate of BAP1 was 31.7% (13/41), including 28.6% (8/28) in CMML-1 patients and 38.5% (5/13) in CMML-2 patients; the positive expression rate of TET2 was 41.5% (17/41), including 39.3% (11/28) in CMML-1 patients and 46.2% (6/13) in CMML-2 patients. In 40 AMML patients, the positive expression rate of BAP1 was 32.5% (13/40), and the positive expression rate of TET2 was 35.0% (14/40). In 20 IDA patients, the positive expression rate of BAP1 was 5.0% (1/20), and TET2 had no positive expression. There was no significant difference in the expressions of BAP1 and TET2 proteins between CMML-1 and CMML-2 patients (χ 2= 0.40, P= 0.53; χ2= 0.17, P= 0.68). There was no significant difference in the expressions of BAP1 and TET2 proteins between CMML and AMML patients (χ 2= 0.01, P= 0.94; χ2= 0.36, P= 0.64). There were significant differences in the positive expression rate of BAP1 and TET2 proteins between hematological neoplastic disease (CMML+AMML) and hematological non-neoplastic disease (IDA) (χ 2= 6.01, P < 0.05; χ 2= 11.04, P < 0.01). Pearson correlation analysis showed that there was no correlation between expressions of BAP1 and TET2 proteins (r= 0.35, P= 0.27). Univariate analysis showed that anemia (Hb < 60 g/L), mature monocyte count ≥ 2.0×109/L, neutrophil count (1.5×109/L), abnormal karyotype were associated with poor prognosis for CMML. Protein expressions of BAP1 and TET2 were not related with the prognosis of CMML (χ 2= 0.28, P= 0.600; χ2= 0.53, P= 0.460). Conclusion Both BAP1 and TET2 proteins have high positive expression rates in CMML patients, but the expressions of them are not related to the prognosis. Key words: Leukemia, myelomonocytic, chronic; BAP1 protein; TET2 protein; Prognosis

Molecular Alterations in Chronic Myelomonocytic Leukemia Monocytes: Transcriptional and Methylation Profiling

Chronic myelomonocytic leukemia (CMML) is a genetically heterogeneous hematopoietic stem cell disorder that combines features of a myelodysplastic syndrome and a myeloproliferative neoplasm and exhibits a strong bias towards older age. The prognosis of CMML is poor, with overall survival of less than 3 years in most studies, however recurrent somatic mutations explain only 15-24% of the clinical heterogeneity of CMML (Elena C. et al. Blood 128:1408-17, 2016). The extreme skewing of the CMML age distribution suggests that CMML reflects the malignant conversion of the myelomonocytic-biased differentiation characteristic of an aged hematopoietic system. We hypothesized that separating the contribution of the normal aging process from bona fide CMML-specific alterations will improve the molecular characterization and biological understanding of CMML. We decided to focus on monocytes as the phenotypic minimal common denominator of genetically heterogeneous diseases. CD14+ monocytes were sorted from the blood of untreated CMML patients (N=12, median age 77 years, range 61-90), age-matched healthy controls (old controls: N=12, median age 68 years, range 62-74) and young healthy controls (young controls: N=16, median age 29 years, range 24-44) and subjected to RNA sequencing and DNA methylation profiling. Differentially expressed genes in CMML monocytes compared to healthy controls were identified with DESeq2 using a 1% false discovery rate (FDR) and a fold-change cutoff set at >│2│ (Figure 1A). We identified the 2480 CMML-specific genes by subtracting all genes with significant differences in the young controls vs. old controls comparison from the CMML vs. old controls comparison. The top-25 most significantly upregulated genes (Figure 1B) included transcription factors, TNFα signaling genes, genes that regulate genomic stability, and genes involved in apoptosis. The most significantly downregulated transcripts were genes involved in response to DNA damage, RNA binding, monocyte differentiation and mediators of inflammatory process.To link these observations to function, we imputed the 2480 CMML-specific differentially expressed genes into the ingenuity pathway analysis (IPA) application. This analysis uncovered significant enrichment of pathways involved in: mitotic roles of Polo-like kinase, G2/M DNA damage checkpoint regulation, lymphotoxin β receptor signaling, IL-6 signaling and ATM signaling (Figure 1C). DNA methylation profiling revealed 909 differentially methylated regions (DMRs) between CMML and age-matched controls, with most regions being hypermethylated in CMML monocytes. Of these, 37% of the DMRs were intronic, 22% were exonic, 14 % were in the promoter region (Figure 1D), 10% were downstream, 10% were upstream, the remainder were 3‘ and 5‘-overlaps.We also performed integrated analysis using the promoter DMRs and the gene expression profile to identify CMML-associated genes that are likely to be regulated by specific changes in methylation. We observed concomitant changes in CMML-specific mRNA transcripts and DNA methylation promoter regions in the CMML vs. old controls contrast for 10 genes (Figure 1E). AOAH, SERINC5, TAF3 and AHCYL1 were downregulated and hypermethylated; MS4A3, TNF, VCAM1, and IFT80, were upregulated and hypermethylated; TUBA1B was upregulated and hypomethylated and PITPNA was downregulated and hypomethylated.Our study is the first to combine transcriptional and methylation profiling for molecular characterization of CMML monocytes. Conclusions: (i) age-related gene expression changes contribute significantly to the CMML transcriptome; (ii) the CMML-specific transcriptome is characterized by differential regulation of transcription factors, inflammatory response genes and anti-apoptotic pathway genes; (iii) differences in promoter methylation represent only a small proportion of overall differences in methylation, suggesting that intragenic or intronic methylation is a major contributor to the leukemic phenotype; (iv) age-related changes may be necessary, but are not sufficient to realize the CMML phenotype. [Display omitted] DisclosuresDeininger:Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Blueprint: Consultancy.

Prognostic Role of Gene Mutations in Chronic Myelomonocytic Leukemia Patients Treated With Hypomethylating Agents

Somatic mutations contribute to the heterogeneous prognosis of chronic myelomonocytic leukemia (CMML). Hypomethylating agents (HMAs) are active in CMML, but analyses of small series failed to identify mutations predicting response or survival. We analyzed a retrospective multi-center cohort of 174 CMML patients treated with a median of 7 cycles of azacitidine (n = 68) or decitabine (n = 106). Sequencing data before treatment initiation were available for all patients, from Sanger (n = 68) or next generation (n = 106) sequencing. Overall response rate (ORR) was 52%, including complete response (CR) in 28 patients (17%). In multivariate analysis, ASXL1 mutations predicted a lower ORR (Odds Ratio [OR] = 0.85, p = 0.037), whereas TET2mut/ASXL1wt genotype predicted a higher CR rate (OR = 1.18, p = 0.011) independently of clinical parameters. With a median follow-up of 36.7 months, overall survival (OS) was 23.0 months. In multivariate analysis, RUNX1mut (Hazard Ratio [HR] = 2.00, p = .011), CBLmut (HR = 1.90, p = 0.03) genotypes and higher WBC (log10(WBC) HR = 2.30, p = .005) independently predicted worse OS while the TET2mut/ASXL1wt predicted better OS (HR = 0.60, p = 0.05). CMML-specific scores CPSS and GFM had limited predictive power. Our results stress the need for robust biomarkers of HMA activity in CMML and for novel treatment strategies in patients with myeloproliferative features and RUNX1 mutations.

Blast Transformation in Chronic Myelomonocytic Leukemia: Risk Factors and Outcome

Background: Prognosis in chronic myelomonocytic leukemia (CMML) is dire and blast transformation (BT) is a main cause of death. Current risk factors and prognostic models are mostly designed to predict overall (OS) and not leukemia-free (LFS) survival. Established risk factors for OS in CMML include anemia, thrombocytopenia, leukocytosis, monocytosis, presence of circulating immature myeloid cells (IMC), peripheral blood (PB) and bone marrow (BM) blasts, lymphocytosis, ASXL1 mutations, high risk abnormal karyotype and advanced age. In the current study, we examined risk factors for BT in CMML and survival outcome after BT.Methods: All CMML patients seen at our institution and with complete presentation data were considered. Clinical and laboratory variables, including cytogenetic information, at time of CMML diagnosis and also at time of BT were collected. DNA analysis for SRSF2, SF3B1, U2AF1, ASXL1 and SETBP1 mutations was carried out on specimens obtained at time of CMML diagnosis. We used both conventional and revised (see accompanying ASH 2014 abstract) cytogenetic risk models to query their influence in the current study population.Results:Clinical and laboratory features at time of CMML diagnosis: 277 consecutive patients (median age 71 years, range 18-91; 67% males) with WHO-defined CMML were considered. 236 (85%) patients had CMML-1 and the remainder CMML-2. According to the molecular Mayo risk model, 86 (33%) were high, 77 (29%) were intermediate-2, 77 (29%) were intermediate-1 and 24 (9%) were low risk. Mutational frequencies were 40% for ASXL1 (n evaluable =264), 44% for SRSF2 (n evaluable =263), 5% for SETBP1 (n evaluable =263). According to the revised Mayo-French consortium cytogenetic risk model, karyotype was high risk in 5%, intermediate in 21% and low risk in 74%.Risk factors for blast transformation (BT): At a median follow-up of 16.2 months for all 277 patients from time of CMML diagnosis, 204 (74%) deaths and 38 (14%) BTs were documented. Median time from CMML diagnosis to BT was 13.3 months. In univariate analysis, female sex, younger age, lower hemoglobin, higher leukocyte count, higher absolute monocyte count, higher lymphocyte count, presence of circulating immature myeloid cells (IMC), increased peripheral blood (PB) blast %, increased bone marrow (BM) blast %, BM blasts ≥10%, CMML-2, abnormal karyotype, high risk karyotype per the Spanish or Mayo-French consortium, and higher risk disease per Mayo, MDACC or Dusseldorf models were all associated with higher risk of BT. In contrast, ASXL1 (p=0.84), SRSF2 (p=0.28) or SETBP1 (p=0.97) mutations were not found to be significant. In multivariable analysis, only PB blast % (p<0.0001), presence of PB IMC (p=0.004) and younger age (p=0.03) remained significant.Outcome of blast transformation: At time of BT, karyotype was abnormal in 58% and clonal evolution from time of CMML diagnosis was documented in 13 (36%) of 36 evaluable patients. Among the 38 patients with BT, induction chemotherapy was documented in 12 patients and allogeneic stem cell transplant (ASCT) in 6. At a median follow-up of 4.2 months from time of BT, 34 (89%) of the 38 patients with BT had died. Among the four patients who were alive at the time of this writing, 3 had received induction chemotherapy and two ASCT. Median survival of patients with BT, from time of disease transformation, was 4.5 months with 1, 2 and 3 year survival rates of approximately 30%, 16% and 3%, respectively. In univariate analysis, higher leukocyte count (p=0.01) and not receiving induction chemotherapy (p=0.03) were associated with shortened survival. Neither ASXL1 nor SRSF2 mutations affected survival after BT.Conclusions: Blast transformation in CMML occurs in approximately 14% of patients followed for a median of less than 1.5 years. Presence of circulating immature cells and percentage of peripheral blood blasts are the major determinants of BT in CMML. Genetic risk factors for overall survival did not appear to influence leukemia-free survival. Prognosis of post-CMML BT is dismal with median survival of less than 6 months and a 3-year survival of less than 5%. Outcome was better in patients receiving induction chemotherapy followed by ASCT. DisclosuresNo relevant conflicts of interest to declare.

Mutation of the colony-stimulating factor-3 receptor gene is a rare event with poor prognosis in chronic myelomonocytic leukemia

Mutation of the colony-stimulating factor-3 receptor gene is a rare event with poor prognosis in chronic myelomonocytic leukemia

Heterogeneity of molecular markers in chronic myelomonocytic leukemia: a disease associated with several gene alterations.

The relatively homogenous clinical features and poor prognosis of chronic myelomonocytic leukemia (CMML) are associated with a molecular heterogeneity, with various mutations impacting several convergent pathways. Due to the restricted understanding of the mechanism involved in leukemogenesis, CMML still appears as a diagnostic and therapeutic undertaking, and poor prognosis of leukemia. Contrary to chronic myelogenous leukemia, BCR-ABL1-positive, cytogenetic, and molecular abnormalities of CMML are not specific and not pathognomonic, confirming the different levels of heterogeneity of this disease. Various mutations can be associated with a common phenotype not distinct at the clinical level, further demonstrating that molecular probings are needed for choosing individual targeted therapies.

Allogeneic stem cell transplantation and donor lymphocyte infusions for chronic myelomonocytic leukemia

Prognosis in chronic myelomonocytic leukemia (CMML) is unfavorable and the optimal therapy remains uncertain. Currently, allogeneic stem cell transplantation is the only known curative therapeutic option. However, the data available are limited and restricted to small retrospective series. There is even less information on the use of donor lymphocyte infusions (DLI) for this disease. We reviewed our experience of allogeneic stem cell transplantation and DLI for adults with CMML. Seventeen consecutive adults underwent allogeneic stem cell transplantation from related (n=14) or unrelated (n=3) donors. Median age was 50 years (range 26-60). Seven patients (41%) demonstrated relapse or persistent disease at a median of 6 months (range 3-55.5). Five patients underwent DLI for morphologic relapse and one for mixed donor chimerism. Two patients achieved durable complete remissions of 15 months each. The overall transplant-related mortality was 41% (n=7). With a median follow-up of 34.5 months, three patients (18%) currently remain alive and in continuous CR. The current study demonstrates a graft-versus-leukemia effect in CMML, both for allogeneic stem cell transplantation and for DLI. Nevertheless, consistent with reported experience of others, overall outcomes remain less than optimal and unpredictable.

Allogeneic Stem Cell Transplantation (ASCT) and Donor Lymphocyte Infusions (DLI) in the Management of Chronic Myelomonocytic Leukemia (CMML).

Background:Overall prognosis in CMML is unfavorable. The only curative option is ASCT, yet the limited data available from the largest reported series, reports 2 year overall (OS) and disease free (DFS) survival of only 21% and 18%, respectively [Kroger et al, BJH 2002, 118: 67]. Data on DLI for CMML are generally restricted to case reports. We retrospectively reviewed our experience of ASCT and DLI for adults with CMML.Patients:Seventeen consecutive patients (11 males) with CMML underwent ASCT from 1992 to 2004. At transplant, median (range) age was 50 years (26–60), duration of disease 7 months (2.5–44), and bone marrow (BM) blast count 6% (1–58%). Prior to transplant, 11 had evolved into acute myeloid leukemia (AML). Of these, 10 received standard induction chemotherapy but only one achieved complete remission (CR); 5 had persistent CMML and 4 refractory AML. Karyotype at transplant was either normal (n=9) or revealed isolated monosomy 7 (n=4), complex (n=1), or single, nonrecurrent abnormalities.ASCT:Conditioning was Cytoxan/Total Body Irradiation in all but one who received a non-myeloablative (NMA) regimen (cladrabine/ATG/thiotepa). Stem cell source was HLA-identical sibling in 14 patients and unrelated in 3 peripheral blood (PB) in 7, BM in 8, or both in 2. Median BM mononuclear cell/kg dose was 2.3 (1.7–4.15) x 108 and PB CD34 cell/kg was 5.12 (0.94–7.29) x 106. Graft versus host disease (GVHD) prophylaxis was cyclosporin alone (n=3), with methotrexate (n=12), or prednisone (n=1) or was tacrolimus/methotrexate (n=1).Post-transplant course:All but one patient who died on day 11 of sepsis engrafted (sustained ANC > 500) at a median of 19.5 days (13–31). CR was documented in 13 (76%) post-ASCT. Acute GVHD was grade II-IV (75%) and III-IV (37.5%) and chronic GVHD was extensive (n=37.5%). Seven (41%) demonstrated relapse or persistent disease at a median of 6 months (3–55.5) and 13 (76%) have died due to disease (n=6) or transplant related mortality (n=7).DLI:Six patients underwent DLI for morphologic (4 recurrent/persistent CMML, 1 early AML with extramedullary disease) or cytogenetic relapse (n=1), at a median of 19.5 days (6–52) post-relapse. Median BM blast count at DLI was 3% (1–22%). The median CD3+ cell dose infused was 30.45 x 107 cells/kg (11.2–45.5), given in a median of 3 infusions (range: 1–3). Four did not respond, but two (one with cytogenetic and one with morphologic relapse) achieved a durable CR of 15 months each, both had extensive CGVHD, from which one died of complications. The other relapsed but failed to respond to a second DLI and died of disease.Survival:For the entire cohort, median DFS and OS were 6 months and 7 months, respectively. At last follow up, 4 remain alive, 3 in continuous CR (18%), at 12, 29 (treated with the NMA regimen) and 116 months, respectively. Of the 3 patients surviving in remission, all had transformed to AML prior to ASCT and only one had achieved CR following induction chemotherapy. Multivariate analysis failed to demonstrate any significant effect of age, duration of disease, BM blast %, karyotype or induction chemotherapy on RFS or OS, likely reflecting the small numbers available for analysis.Conclusion:The current study demonstrates anti-CMML activity of both ASCT and DLI although overall outcome is less than encouraging and unpredictable. Novel approaches are needed.

Chronic Myelomonocytic Leukemia According to FAB Classification: Analysis of 35 Cases

Thirty-five patients who fulfilled the FAB diagnosis criteria of chronic myelomonocytic leukemia (CMML), i.e., myelodysplastic features, monocytosis over 10(9)/liter, bone marrow monocyte infiltration, blast cells less than 5% in the peripheral blood and less than 30% in the bone marrow, are analyzed. CMML appears as an entity distinct from myelodysplastic and myeloproliferative disorders. Splenomegaly, anemia, thrombocytopenia, leukocytosis with monocytes and granulocytic cells in all stages of development, increased blood and urine lysozyme levels without renal failure, and polyclonal hyperimmunoglobulinemia are its main clinical and biologic features. With conventional cytotoxic drugs (6-mercaptopurine, hydroxyurea), the prognosis of CMML appears poor (median survival 475 days). None of the clinical hematologic or biologic parameters tested had a significant effect on prognosis. As other chemotherapy trials seemed necessary, we recently administered small doses of cytosine-arabinoside (ARA-C) to six patients over several consecutive days and obtained a complete remission in four. These preliminary results must be confirmed by larger series using the diagnostic criteria proposed by the FAB cooperative group.

Chronic myelomonocytic leukemia according to FAB classification: analysis of 35 cases

Thirty-five patients who fulfilled the FAB diagnosis criteria of chronic myelomonocytic leukemia (CMML), i.e., myelodysplastic features, monocytosis over 10(9)/liter, bone marrow monocyte infiltration, blast cells less than 5% in the peripheral blood and less than 30% in the bone marrow, are analyzed. CMML appears as an entity distinct from myelodysplastic and myeloproliferative disorders. Splenomegaly, anemia, thrombocytopenia, leukocytosis with monocytes and granulocytic cells in all stages of development, increased blood and urine lysozyme levels without renal failure, and polyclonal hyperimmunoglobulinemia are its main clinical and biologic features. With conventional cytotoxic drugs (6-mercaptopurine, hydroxyurea), the prognosis of CMML appears poor (median survival 475 days). None of the clinical hematologic or biologic parameters tested had a significant effect on prognosis. As other chemotherapy trials seemed necessary, we recently administered small doses of cytosine-arabinoside (ARA-C) to six patients over several consecutive days and obtained a complete remission in four. These preliminary results must be confirmed by larger series using the diagnostic criteria proposed by the FAB cooperative group.