Venous and arterial thrombosis in patients with VEXAS syndrome.

ABSTRACT: VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome, caused by somatic mutations in UBA1, is an autoinflammatory disorder with diverse systemic manifestations. Thrombosis is a prominent clinical feature of VEXAS syndrome. The risk factors and frequency of thrombosis in VEXAS syndrome are not well described, due to the disease's recent discovery and the paucity of large databases. We evaluated 119 patients with VEXAS syndrome for venous and arterial thrombosis and correlated their presence with clinical outcomes and survival. Thrombosis occurred in 49% of patients, mostly venous thromboembolism (VTE; 41%). Almost two-thirds of VTEs were unprovoked, 41% were recurrent, and 20% occurred despite anticoagulation. The cumulative incidence of VTE was 17% at 1 year from symptom onset and 40% by 5 years. Cardiac and pulmonary inflammatory manifestations were associated with time to VTE. M41L was positively associated specifically with pulmonary embolism by univariate (odds ratio [OR]: 4.58, confidence interval [CI] 1.28-16.21, P = .02) and multivariate (OR: 16.94, CI 1.99-144.3, P = .01) logistic regression. The cumulative incidence of arterial thrombosis was 6% at 1 year and 11% at 5 years. The overall survival of the entire patient cohort at median follow-up time of 4.8 years was 88%, and there was no difference in survival between patients with or without thrombosis (P = .8). Patients with VEXAS syndrome are at high risk of VTE; thromboprophylaxis should administered be in high-risk settings unless strongly contraindicated.

Spectrum of clonal hematopoiesis in VEXAS syndrome.

Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome is caused by somatic mutations in UBA1 (UBA1mut) and characterized by heterogenous systemic autoinflammation and progressive hematologic manifestations, meeting criteria for myelodysplastic syndrome (MDS) and plasma cell dyscrasias. The landscape of myeloid-related gene mutations leading to typical clonal hematopoiesis (CH) in these patients is unknown. Retrospectively, we screened 80 patients with VEXAS for CH in their peripheral blood (PB) and correlated the findings with clinical outcomes in 77 of them. UBA1mut were most common at hot spot p.M41 (median variant allele frequency [VAF] = 75%). Typical CH mutations cooccurred with UBA1mut in 60% of patients, mostly in DNMT3A and TET2, and were not associated with inflammatory or hematologic manifestations. In prospective single-cell proteogenomic sequencing (scDNA), UBA1mut was the dominant clone, present mostly in branched clonal trajectories. Based on integrated bulk and scDNA analyses, clonality in VEXAS followed 2 major patterns: with either typical CH preceding UBA1mut selection in a clone (pattern 1) or occurring as an UBA1mut subclone or in independent clones (pattern 2). VAF in the PB differed markedly between DNMT3A and TET2 clones (median VAF of 25% vs 1%). DNMT3A and TET2 clones associated with hierarchies representing patterns 1 and 2, respectively. Overall survival for all patients was 60% at 10 years. Transfusion-dependent anemia, moderate thrombocytopenia, and typical CH mutations, each correlated with poor outcome. In VEXAS, UBA1mut cells are the primary cause of systemic inflammation and marrow failure, being a new molecularly defined somatic entity associated with MDS. VEXAS-associated MDS is distinct from classical MDS in its presentation and clinical course.

Acute kidney injury, an underrecognized feature of VEXAS syndrome.

OBJECTIVES: VEXAS syndrome is an autoinflammatory disease caused by somatic mutation of UBA1 and affects multiple organ systems. Involvement of the kidneys is not well characterized. We aimed to investigate the incidence, risk factors and histopathologic features of acute kidney injury (AKI) in VEXAS syndrome. METHODS: Patients with genetically confirmed UBA1 mutation consistent with VEXAS were included. Charts were manually reviewed. Cox regression analysis was used to identify variables associated with time-to-first acute kidney injury (AKI) event. For patients with a kidney biopsy, histopathologic findings were reviewed. RESULTS: Eighty-one patients were included, all white men, with a mean age of 66.3±8.6 years. Median (IQR) follow up was 3.5 (2.1-5.2) years during which 20 (25%) developed AKI and 22% died. AKI relapsed in 90% of cases for a median of 6 times during the follow up period. Cumulative incidence estimates (95% CI) for AKI at 1, 3 and 5 years were 6.2% (0.80-11.3%), 16.7% (7.5-25.0%) and 27.9% (14.9-38.9%), respectively. Age and baseline C-reactive protein were significantly associated with time-to-first AKI event. Six patients underwent a kidney biopsy. Findings included, plasma cell-rich interstitial nephritis (n = 3), neutrophilic-rich interstitial inflammation (n = 1), leukocytoclastic peritubular capillaritis (n = 1), and acute tubular injury (n = 1). AKI responded well to treatment with glucocorticoids but had relapse upon tapering. CONCLUSION: AKI is an underrecognized feature of VEXAS occurring in 25% of patients in this cohort. Age at diagnosis and CRP were associated with time to first AKI event during follow up. Plasma cell-rich interstitial nephritis was the most common histopathologic finding.

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

Mutations 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 relevance of clonal hematopoiesis in myeloid neoplastic transformation in patients with follicular lymphoma treated with radioimmunotherapy.

While novel radioisotope therapies continue to advance cancer care, reports of therapy-related myeloid neoplasms (t-MN) have generated concern. The prevalence and role of clonal hematopoiesis (CH) in this process remain to be defined. We hypothesized that: (i) CH is prevalent in relapsed follicular lymphoma and is associated with t-MN transformation, and (ii) radiation in the form of radioimmunotherapy (RIT) plays a role in clonal progression. In this retrospective cohort study, we evaluated the prevalence and prognostic impact of CH on clinical outcomes in 58 heavily pre-treated follicular lymphoma patients who received RIT. Patients had been given a median of four lines of therapy before RIT. The prevalence of CH prior to RIT was 46%, while it was 67% (P=0.15) during the course of RIT and subsequent therapies in the paired samples. Fourteen (24%) patients developed t-MN. Patients with t-MN had a higher variant allele fraction (38% vs. 15%; P=0.02) and clonal complexity (P=0.03) than those without. The spectrum of CH differed from that in age-related CH, with a high prevalence of DNA damage repair and response pathway mutations, absence of spliceosome mutations, and a paucity of signaling mutations. While there were no clear clinical associations between RIT and t-MN, or overall survival, patients with t-MN had a higher mutant clonal burden, along with extensive chromosomal abnormalities (median survival, afer t-MN diagnosis, 0.9 months). The baseline prevalence of CH was high, with an increase in prevalence on exposure to RIT and subsequent therapies. The high rates of t-MN with marked clonal complexities and extensive chromosomal damage underscore the importance of better identifying and studying genotoxic stressors accentuated by therapeutic modalities.

ASXL1/TET2 genotype-based risk stratification outperforms ASXL1 mutational impact and is independent of mutant variant allele fractions in chronic myelomonocytic leukemia.

Not available.

VEXAS syndrome: Clinical, hematologic features and a practical approach to diagnosis and management.

VEXAS (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) syndrome is a newly identified disease caused by somatic alterations in UBA1 which produce a recalcitrant inflammatory state along with hematologic disturbances. Patients with VEXAS can have a wide spectrum of clinical symptoms and providers should be familiar with the heterogeneity of associated clinical features. While hematologic parameters may be generally non-specific, peripheral blood features of macrocytosis, monocytopenia, and/or thrombocytopenia coupled with bone marrow vacuolization of erythroid or myeloid precursors should raise suspicion for this condition. Due to an increased mortality, prompt recognition and accurate diagnosis is paramount. Access to testing for confirmation of UBA1 variants is not yet universally available but clinicians should understand the current available options for genetic confirmation of this disease. Treatment options are limited due to lack of prospective clinical trials but cytokine directed therapies such as interleukin-6 inhibitors and JAK-STAT inhibitors as well as hypomethylating agents such as azacitidine have shown evidence of partial effect. Though cases are limited, allogeneic stem cell transplantation holds promise for durable response and potential cure. The intent of this review is to outline the pathophysiology of VEXAS syndrome and to provide a practical approach to diagnosis and treatment.

Clonal Hematopoiesis of Indeterminate Potential Is Associated With Coronary Microvascular Dysfunction In Early Nonobstructive Coronary Artery Disease.

BACKGROUND: Clonal hematopoiesis (CH) of indeterminate potential (CHIP) is a risk factor for cardiovascular disease. The relationship between CHIP and coronary microvascular dysfunction (CMD) is unknown. The current study examines the association between CHIP and CH with CMD and the potential relationships in risk for adverse cardiovascular outcomes. METHODS: In this retrospective observational study, targeted next-generation sequencing was performed for 177 participants with no coronary artery disease who presented with chest pain and underwent routine coronary functional angiogram. Patients with somatic mutations in leukemia-associated driver genes in hematopoietic stem and progenitor cells were examined; CHIP was considered at a variant allele fraction ≥2%; CH was considered at a variant allele fraction ≥1%. CMD was defined as coronary flow reserve to intracoronary adenosine of ≤2. Major adverse cardiovascular events considered were myocardial infarction, coronary revascularization, or stroke. RESULTS: A total of 177 participants were examined. Mean follow-up was 12±7 years. A total of 17 patients had CHIP and 28 had CH. Cases with CMD (n=19) were compared with controls with no CMD (n=158). Cases were 56±9 years, were 68% women, and had more CHIP (27%; P=0.028) and CH (42%; P=0.001) than controls. CMD was associated with independent risk for major adverse cardiovascular events (hazard ratio, 3.89 [95% CI, 1.21-12.56]; P=0.023), and 32% of this risk was mediated by CH. The risk mediated by CH was ≈0.5× as large as the direct effect of CMD on major adverse cardiovascular events. CONCLUSIONS: In humans, we observe patients with CMD are more likely to have CHIP, and nearly one-third of major adverse cardiovascular events in CMD are mediated by CH.

Targeted testing of bone marrow specimens with cytoplasmic vacuolization to identify previously undiagnosed cases of VEXAS syndrome.

OBJECTIVE: To retrospectively identify patients with VEXAS syndrome (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome) among male patients with bone marrow vacuolization using a clinically applicable, targeted-screening approach. METHODS: Bone marrow reports from 1 May 2014 through 18 February 2022 were reviewed for documentation of cytoplasmic vacuolization. Patients with acute leukaemia, lymphoma, metastatic solid tumour, amyloidosis or POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes) syndrome were excluded, as were those without clinical records available for direct chart review. Cases were rated for suspicion of VEXAS syndrome using a 5-point scale based on the presence of laboratory findings, clinical features and treatment response. Patients with available DNA material and moderate (three patients) or high (four to five patients) suspicion were tested for somatic UBA1 variants associated with VEXAS syndrome. RESULTS: A total of 315 reports from 292 unique patients included documentation of vacuolization. Following exclusion criteria, 64 patients underwent direct medical chart review to assess likelihood of VEXAS syndrome, for which 21 patients met moderate to high suspicion. Available DNA was present in eight patients, seven (87.5%) of whom had a pathogenic somatic UBA1 variant consistent with VEXAS syndrome. The distribution of cytoplasmic vacuolization in the bone marrow biopsy reports among patients with VEXAS syndrome were erythroid and myeloid precursors (6/7), erythroid precursors only (1/7) and myeloid precursors only (0/7). CONCLUSION: In this study, the utilization of a clinically applicable targeted-screening approach to test bone marrow specimens (with vacuolization) for the presence of previously undiagnosed VEXAS syndrome resulted in a positive detection rate of 87.5%.

Clinical and molecular correlates of somatic and germline DDX41 variants in patients and families with myeloid neoplasms.

The diagnosis of germline predisposition to myeloid neoplasms (MN) secondary to DDX41 variants is currently hindered by the long latency period, variable family histories and the frequent occurrence of DDX41 variants of uncertain significance (VUS). We reviewed 4,524 consecutive patients who underwent targeted sequencing for suspected or known MN and analyzed the clinical impact and relevance of DDX41VUS in comparison to DDX41path variants. Among 107 patients (44 [0.9%] DDX41path and 63 DDX41VUS [1.4%; 11 patients with both DDX41path and DDX41VUS]), we identified 17 unique DDX41path and 45 DDX41VUS variants: 24 (23%) and 77 (72%) patients had proven and presumed germline DDX41 variants, respectively. The median age was similar between DDX41path and DDX41VUS (66 vs. 62 years; P=0.41). The median variant allele frequency (VAF) (47% vs. 48%; P=0.62), frequency of somatic myeloid co-mutations (34% vs 25%; P= 0.28), cytogenetic abnormalities (16% vs. 12%; P=>0.99) and family history of hematological malignancies (20% vs. 33%; P=0.59) were comparable between the two groups. Time to treatment in months (1.53 vs. 0.3; P=0.16) and proportion of patients progressing to acute myeloid leukemia (14% vs. 11%; P=0.68), were similar. The median overall survival in patients with high-risk myelodysplastic syndrome/acute myloid leukemia was 63.4 and 55.7 months in the context of DDX41path and DDX41VUS, respectively (P=0.93). Comparable molecular profiles and clinical outcomes among DDX41path and DDX41VUS patients highlights the need for a comprehensive DDX41 variant interrogation/classification system, to improve surveillance and management strategies in patients and families with germline DDX41 predisposition syndromes.

Patients with telomere biology disorders show context specific somatic mosaic states with high frequency of U2AF1 variants.

Somatic mosaic states in telomere biology disorders are characterized by somatic variants in the spliceosome and DNA damage response and repair pathways. A likely maladaptive response to short telomeres that may lead to increased hematological cancer.

Single-cell genomics reveals the genetic and molecular bases for escape from mutational epistasis in myeloid neoplasms.

Large-scale sequencing studies of hematologic malignancies have revealed notable epistasis among high-frequency mutations. One of the most striking examples of epistasis occurs for mutations in RNA splicing factors. These lesions are among the most common alterations in myeloid neoplasms and generally occur in a mutually exclusive manner, a finding attributed to their synthetic lethal interactions and/or convergent effects. Curiously, however, patients with multiple-concomitant splicing factor mutations have been observed, challenging our understanding of one of the most common examples of epistasis in hematologic malignancies. In this study, we performed bulk and single-cell analyses of patients with myeloid malignancy who were harboring ≥2 splicing factor mutations, to understand the frequency and basis for the coexistence of these mutations. Although mutations in splicing factors were strongly mutually exclusive across 4231 patients (q < .001), 0.85% harbored 2 concomitant bona fide splicing factor mutations, ∼50% of which were present in the same individual cells. However, the distribution of mutations in patients with double mutations deviated from that in those with single mutations, with selection against the most common alleles, SF3B1K700E and SRSF2P95H/L/R, and selection for less common alleles, such as SF3B1 non-K700E mutations, rare amino acid substitutions at SRSF2P95, and combined U2AF1S34/Q157 mutations. SF3B1 and SRSF2 alleles enriched in those with double-mutations had reduced effects on RNA splicing and/or binding compared with the most common alleles. Moreover, dual U2AF1 mutations occurred in cis with preservation of the wild-type allele. These data highlight allele-specific differences as critical in regulating the molecular effects of splicing factor mutations as well as their cooccurrences/exclusivities with one another.

Sustained, complete response to pexidartinib in a patient with CSF1R-mutated Erdheim-Chester disease.

Erdheim-Chester disease (ECD) is a histiocytic neoplasm that predominantly harbors mitogen-activated protein kinase (MAPK) pathway variants. MAPK inhibitors typically are effective treatments, but mutations outside the MAPK pathway, such as CSF1R variants, may cause refractory ECD. We describe a patient with a novel somatic mutation in CSF1R (CSF1RR549_E554delinsQ ) that resulted in refractory ECD affecting the central nervous system. Cell model studies, RNA sequencing analysis, and in silico protein modeling suggested that she had a gain-of-function mutation occurring in a region critical for autoinhibition. The patient was treated with pexidartinib, a CSF1R inhibitor, and has had a complete clinical and metabolic response lasting more than 1.5 years to date. To our knowledge, this is the first report to describe successful treatment of a patient with ECD by using an agent that specifically targets CSF1R. This case also highlights the critical role of individualized molecular profiling to identify novel therapeutic targets in ECD.

Spectrum of hematological malignancies, clonal evolution and outcomes in 144 Mayo Clinic patients with germline predisposition syndromes.

Germline predisposition syndromes (GPS) result from constitutional aberrations in tumor suppressive and homeostatic genes, increasing risk for neoplasia in affected kindred. In this study, we present clinical and genomic data on 144 Mayo Clinic patients with GPS; 59 evaluated prospectively using an algorithm-based diagnostic approach in the setting of a dedicated GPS/ inherited bone marrow failure syndrome (IBMFS) clinic. Seventy-two (50%) patients had IBMFS (telomere biology disorders-32,Fanconi anemia-18, Diamond Blackfan Anemia - 11, congenital neutropenia-5, Schwachman-Diamond Syndrome-5 and Bloom Syndrome-1), 27 (19%) had GPS with antecedent thrombocytopenia (RUNX1-FPD-15, ANKRD26-6, ETV6-2, GATA1-1, MPL-3), 28 (19%) had GPS without antecedent thrombocytopenia (GATA2 haploinsufficiency-16, DDX41-10, CBL-1 and CEBPA-1) and 17 (12%) had general cancer predisposition syndromes (ataxia telangiectasia-7, heterozygous ATM variants-3, CHEK2-2, TP53-2, CDK2NA-1, NF1-1 and Nijmegen Breakage Syndrome-1). Homozygous and heterozygous ATM pathogenic variants were exclusively associated with lymphoproliferative disorders (LPD), while DDX41 GPS was associated with LPD and myeloid neoplasms. The use of somatic NGS-testing identified clonal evolution in GPS patients, with ASXL1, RAS pathway genes, SRSF2 and TET2 being most frequently mutated. Fifty-two (91%) of 59 prospectively identified GPS patients had a change in their management approach, including additional GPS-related screening in 42 (71%), referral for allogenic HSCT workup and screening of related donors in 16 (27%), medication initiation and selection of specific conditioning regimens in 14 (24%), and genetic counseling with specific intent of fertility preservation and preconceptual counseling in 10 (17%) patients; highlighting the importance of dedicated GPS screening, detection and management programs for patients with hematological neoplasms.

Mutation-enhanced international prognostic systems for essential thrombocythaemia and polycythaemia vera.

Survival prediction in essential thrombocythaemia (ET) and polycythaemia vera (PV) is currently based on clinically-derived variables; we examined the possibility of integrating genetic information for predicting survival. To this end, 906 molecularly-annotated patients (416 Mayo Clinic; 490 University of Florence, Italy), including 502 ET and 404 PV, were recruited. Multivariable analysis identified spliceosome mutations to adversely affect overall (SF3B1, SRSF2 in ET and SRSF2 in PV) and myelofibrosis-free (U2AF1, SF3B1 in ET) survival; TP53 mutations predicted leukaemic transformation in ET; "adverse" mutations occurred in 51 (10%) ET and 8 (2%) PV patients. We confirmed the independent survival effect of adverse mutations [hazard ratio (HR) 2·4, 95% CI 1·6-3·5], age >60 years (6·6, 4·6-9·7), male sex (1·8, 1·3-2·4) and leukocytosis ≥11 × 109 /l (1·6, 1·1-2·2), in ET, and adverse mutations (7·8, 3·1-17·0), age >67 years (5·4, 3·6-8·1), leukocytosis ≥15 × 109 /l (2·8, 1·8-4·2) and thrombosis history (2·0, 1·4-2·9), in PV. HR-based risk point allocation allowed development of three-tiered mutation-enhanced international prognostic systems (MIPSS) which were validated in both cohorts and performance was shown to be superior to conventional scoring systems. Spliceosome mutations enhance survival prediction in ET and PV and identify patients at risk for fibrotic progression. TP53 mutations predict leukaemic transformation in ET.

The germline JAK2 GGCC (46/1) haplotype and survival among 414 molecularly-annotated patients with primary myelofibrosis.

JAK2 mutations in myeloproliferative neoplasms (MPNs) are associated with the germline GGCC (46/1) haplotype. In 2010, we reported an association between shortened survival in primary myelofibrosis (PMF) and nullizygosity for the JAK2 46/1 haplotype. In the current study, we have increased the number of informative cases from 130 to 414 (median age 63 years; 63% males), in order to revisit with the phenotypic and prognostic relevance of the JAK2 46/1 haplotype in PMF. JAK2 46/1 haplotype was documented in 69% of the study patients, including 25% in homozygous and 44% in heterozygous state. Driver mutation frequency in patients homozygous/heterozygous/nullizygous for the 46/1 haplotype was 78%/60%/56% JAK2, 10%/20%/18% type 1-like CALR, 3%/2%/5% type 2-like CALR, 4%/8%/7% MPL, and 6%/10%/14% triple-negative (P = .02). In univariate analysis, nullizygosity for the JAK2 46/1 haplotype was associated with inferior overall survival (HR 1.5, 95% CI 1.1-1.9), most pronounced in JAK2 (P <.001), as opposed to CALR/MPL mutated (P = .48) or triple-negative cases (P = .27). Multivariable analysis that included karyotype, driver mutational status and high-molecular risk mutations confirmed the independent prognostic contribution of nullizygosity for the 46/1 haplotype (P = .02; HR 1.4, 95% CI 1.1-1.8). Nullizygosity for 46/1 also remained significant in the context of the genetically-inspired GIPSS risk model (P = .04), but not in the context of the integrated genetics-clinical MIPSS70+ version 2.0 model (P = .4). Leukemia-free survival was not affected by the 46/1 haplotype (P = .6). The current study confirms the association of nullizygosity for the JAK2 GGCC (46/1) haplotype with inferior survival in JAK2-mutated PMF.

20+ Years and alive with primary myelofibrosis: Phenotypic signature of very long-lived patients.

In the last decade, several prognostic models for primary myelofibrosis (PMF) have been introduced and shown to be effective in predicting overall survival. The main objective for this study was to identify clinical and genetic markers of very long (20+ years) survival in PMF. A total of 1282 patients with PMF were considered (median age 65 years, range 19-92; 63% males); 26 (2%) patients (median age 51 years, range 28-71; 38% males) survived their disease for at least 20 years (long-lived patients) and 626 (49%) patients (median age 68 years, range 27-92; 66% males) died within 5 years of their diagnosis (short-lived patients). Multivariable logistic regression analysis identified 7 variables that were associated with survival beyond 20 years: age ≤ 70 years (P = .002); female sex (P = .03); hemoglobin level ≥ 10 g/dL for women and ≥ 11 g/dL for men (P = .03), leukocyte count ≤25 × 109 /L (P = .009), platelet count ≥100 × 109 /L (P = .002), circulating blasts <2% (P = .03) and absence of constitutional symptoms (P = .04). Five-year mortality was independently predicted by high-molecular risk mutations (P < .001); unfavorable or very high risk karyotype (P < .001); absence of type 1/like CALR mutation (P < .001); age > 70 years (P < .001); constitutional symptoms (P < .001); hemoglobin level < 10 g/dL for women and < 11 g/dL for men (P < .001); leukocyte count >25 × 109 /L (P = .004); and circulating blasts ≥2% (P = .001). This study suggests that genetic risk factors in PMF are associated with early mortality while survival beyond 20 years could be predicted by easily accessible clinical variables, including age, sex, blood counts, and symptoms.

Suboptimal response rates to hypomethylating agent therapy in chronic myelomonocytic leukemia; a single institutional study of 121 patients.

Hypomethylating agents (HMA) are currently the only FDA approved therapy for patients with chronic myelomonocytic leukemia (CMML). In the current retrospective study, we assessed response rates as adjudicated by the IWG (International Working Group) MDS (myelodysplastic syndrome) and MDS/MPN myeloproliferative neoplasm overlap syndrome response criteria, in 121 CMML patients treated with Azacitidine (AZA, n = 56) and Decitabine (DAC, n = 65). The overall response rates were 41% by the IWG MDS (AZA- 45%, DAC-39%), and 56% by the IWG MDS/MPN (AZA-56%, DAC-58%) response criteria, with CR (complete remission) rates of <20% for both agents, by both criteria. There were no significant differences in response rates between proliferative and dysplastic CMML. Moreover, 29% of CMML patients in a CR with HMA progressed to AML (blast transformation), underscoring the limited impact of these agents on disease biology. Progression after HMA response was associated with a median overall-survival (OS) of 8 months, while median OS in patients with primary HMA failure was 4 months. Lower serum LDH levels (<250 Units/L) were associated with HMA responses by both criteria; while ASXL1 and TET2 mutational status had no impact. HMA treated patients had a longer median OS (31 vs 18 months; P = .01), in comparison to those treated with conventional care regimens (excluding observation only patients), without any differences between AZA vs DAC (P = .37). In conclusion, this study highlights the inadequacies of HMA therapy in CMML, retrospectively validates the IWG MDS/MPN response criteria and underscores the need for newer, rationally derived therapies.

A Pilot Study of the Telomerase Inhibitor Imetelstat for Myelofibrosis.

BACKGROUND: Current drugs for myeloproliferative neoplasm-associated myelofibrosis, including Janus kinase (JAK) inhibitors, do not induce complete or partial remissions. Imetelstat is a 13-mer lipid-conjugated oligonucleotide that targets the RNA template of human telomerase reverse transcriptase. METHODS: We sought to obtain preliminary information on the therapeutic activity and safety of imetelstat in patients with high-risk or intermediate-2-risk myelofibrosis. Imetelstat was administered as a 2-hour intravenous infusion (starting dose, 9.4 mg per kilogram of body weight) every 1 to 3 weeks. The primary end point was the overall response rate, and the secondary end points were adverse events, spleen response, and independence from red-cell transfusions. RESULTS: A total of 33 patients (median age, 67 years) met the eligibility criteria; 48% had received prior JAK inhibitor therapy. A complete or partial remission occurred in 7 patients (21%), with a median duration of response of 18 months (range, 13 to 20+) for complete responses and 10 months (range, 7 to 10+) for partial responses. Bone marrow fibrosis was reversed in all 4 patients who had a complete response, and a molecular response occurred in 3 of the 4 patients. Response rates were 27% among patients with a JAK2 mutation versus 0% among those without a JAK2 mutation (P=0.30) and 32% among patients without an ASXL1 mutation versus 0% among those with an ASXL1 mutation (P=0.07). The rate of complete response was 38% among patients with a mutation in SF3B1 or U2AF1 versus 4% among patients without a mutation in these genes (P=0.04). Responses did not correlate with baseline telomere length. Treatment-related adverse events included grade 4 thrombocytopenia (in 18% of patients), grade 4 neutropenia (in 12%), grade 3 anemia (in 30%), and grade 1 or 2 elevation in levels of total bilirubin (in 12%), alkaline phosphatase (in 21%), and aspartate aminotransferase (in 27%). CONCLUSIONS: Imetelstat was found to be active in patients with myelofibrosis but also had the potential to cause clinically significant myelosuppression. (Funded by Geron; ClinicalTrials.gov number, NCT01731951.).

Mutations and karyotype predict treatment response in myelodysplastic syndromes.

We examined the influence of mutations and karyotype on conventional treatment response, specifically hematological improvement in anemia, in primary myelodysplastic syndromes (MDS). Cytogenetic and next generation sequencing (NGS)-derived mutation information was available in 357 patients (median age 74 years; 70% males); the revised international prognostic scoring system risk distribution was very high in 11%, high 15%, intermediate 17%, low 40% and very low 16%. At least one mutation was detected in 81% of patients; most frequent were SF3B1 (32%), ASXL1 (27%), TET2 (24%) and U2AF1 (15%). At median follow-up of 24 months, treatment with hypomethylating agents (HMAs) was documented in 121 (34%) patients, lenalidomide (LEN) in 55 (15%), and erythropoiesis stimulating agents (ESAs) in 136 (38%). ASXL1 mutations adversely affected response to HMAs (27% vs 48%; P = 0.02) and LEN (9% vs 43%; P = 0.04), but not ESAs (P = 0.6). LEN response was also adversely affected by U2AF1 mutations (0% vs 42%; P = 0.02) and high risk karyotype (0% vs 41% in intermediate vs 47% in low risk; P = 0.01). Patients with SF3B1 mutations were more likely to respond to LEN (56% vs 27%; P = 0.04). Contrary to previous reports, we found no association between TET2 mutations and HMA treatment response (40% vs 41%; P = 0.9), even in the absence of ASXL1 mutations (P = 0.4).We conclude that ASXL1 mutations in MDS predict inferior response to treatment with both HMAs and LEN; response to LEN was also compromised by U2AF1 mutations and high risk karyotype; SF3B1 mutations identified patients likely to respond to LEN.